Dual-Phase Coexistence Design and Advanced Electrochemical Performance of Cu₂MoS₄ Electrode Materials for Supercapacitor Application: Ren Hao Xu, Pian Pian Ma, Guan Fu Liu, Yin Qiao, Rui Yang Hu, Li Yuan Liu, Muslum Demir, and Guo Hua Jiang; Energy Fuels 2023, 37, 8, 6158–6167 (https://doi.org/10.1021/acs.energyfuels.2c04273)

Abstract

The tetragonal layered transition metal copper–molybdenum sulfide Cu₂MoS₄ (CMS) possesses a high theoretical electrochemical potential because of its abundant redox properties and large layered surface area, which is favorable for ion adsorption/desorption and transport. Cu₂MoS₄ contains P and I phases, exhibiting different crystal structures, ion transport characteristics, and electrochemical properties accordingly. In this work, for the first time, Cu₂MoS₄ electrode materials with dual-phase compositions are designed and prepared for supercapacitor application, providing a synergistic effect with high electron transport efficiency and structural stability. Upon an in-depth optimization process, the optimal CMS-4 sample having P and I phases coexisting yields the optimal electrochemical behavior. The CMS-4@carbon cloth (CC) electrode provides a specific capacity of 33.9 mAh g^–1 at 1 A g^–1, which is 12.6 and 4.0 times higher than the pure P and I phases, respectively. The assembled MnO₂@CC//CMS-4@CC supercapacitor exhibits a high energy density of 16.8 Wh kg^–1 at 800 W kg^–1 power density. The results demonstrate that two-phase coexistence of Cu₂MoS₄ significantly enhances the electrochemical activities owing to the synergistic effects of P and I phases and provides a promising material for supercapacitor negative electrodes.

Minireview on the Leakage Ignition and Flame Propagation Characteristics of Hydrogen: Advances and Perspectives: Caiping Wang, Lingchen Zhao, Jiao Qu, Yang Xiao, Jun Deng, and Chi-Min Shu; Energy Fuels 2023, 37, 8, 5653–5666 (https://doi.org/10.1021/acs.energyfuels.2c03866)

Abstract

Hydrogen energy is a clean and efficient type of green energy whose use has been widely promoted. However, because of its physical and chemical characteristics, hydrogen tends to cause fires and explosions under certain conditions, which restricts its widespread application. After briefly describing the danger of high-pressure hydrogen (HPH), this paper summarizes the ignition and flame propagation characteristics of HPH leakage diffusion and describes the influences of various factors, such as leakage location, initial leakage velocity, initial pressure, presence of vents, ignition location, pipe size, and presence of obstacles, on these characteristics. HPH is likely to ignite spontaneously at the moment of leakage, and this ignition involves complex dynamics. Finally, the gap in the current research on HPH is described, and suggestions are provided for future research to promote the safe and efficient use of hydrogen energy.

Techno-Economic Assessment of Natural Gas Combined Cycle Power Plants with Carbon Capture and Utilization: Zhiwei Zhang, Dong-Hoon Oh, Vo Dat Nguyen, Chang-Ha Lee, and Jae-Cheol Lee; Energy Fuels 2023, 37, 8, 5961–5975 (https://doi.org/10.1021/acs.energyfuels.3c00122)

Abstract

Carbon utilization in natural gas combined cycle (NGCC) power plants has attracted great attention due to necessary carbon reduction demands. In this study, NGCC power plants integrated with the carbon capture and utilization process (CCU) were developed: Case 2 (NGCC power plant with CO₂ conversion on precarbon capture) and case 3 (NGCC power plant with CO₂ conversion on postcarbon capture). Integrated process configurations were evaluated and compared with case 1 (NGCC power plant only with postcombustion carbon capture) in terms of technical (net power generation, natural gas consumption rate, syngas production rate, CO₂ quantity released into the environment) and economic (total capital cost, total annual revenue, return on investment, payback period, and cash flow) performance. Here, case 2 represented the most environmentally friendly option with the lowest CO₂ released. Besides, case 3 generated the highest amount of electricity due to a lower compression pressure demand for CO₂ utilization than storage in case 1. The economic analysis indicated that the payback periods of cases 1, 2, and 3 were 9.2, 17.18, and 6.9, respectively. Case 3 was the best option under the least capital expenditure, operating expenditure, and the highest annual revenue. Additionally, case 2 was competitive in terms of low total capital cost as compared to case 1. Therefore, the suggested NGCC power plant processes with CCU are viable options for reducing CO₂ emissions and improving the economics of NGCC power plants. In addition, the process may be used as a model for further CO₂ utilization from flue gas released by gas power plants.

Mn-Doped Na₄Fe₃(PO₄)₂P₂O₇ as a Low-Cost and High-Performance Cathode Material for Sodium-Ion Batteries: Qingdong Tao, Haiyang Ding, Xin Tang, Kaibo Zhang, Jinhan Teng, Haomiao Zhao, and Jing Li; Energy Fuels 2023, 37, 8, 6230–6239 (https://doi.org/10.1021/acs.energyfuels.3c00340)

Abstract

Na₄Fe₃(PO₄)₂P₂O₇ (NFPP) is considered to be an ideal cathode material for sodium-ion batteries due to its high theoretical capacity, stable structure, small volume change, low cost, and nontoxicity. However, the inherent low electronic conductivity of polyanionic materials limits the application of this material. In this work, we improved the electronic conductivity and structural stability of the material through a dual modification synergistic strategy of manganese ion doping and surface carbon coating and prepared Na₄Fe_2.9Mn_0.1(PO₄)₂P₂O₇@C (0.1 Mn-NFPP@C) composites by a simple mechanical-assisted chemical synthesis method. It can release 119.6 mAh g^–1 at 0.1C. The capacity retention rate is 97.4% after 100 cycles at 1C and 84.8% after 3000 cycles at 10C. Many tests and calculations in this work also show that 0.1 Mn-NFPP@C modified by Mn²⁺ doping and carbon coating has higher electronic conductivity and electrochemical kinetics and thus exhibits better electrochemical performance.

Modeling Biomass Particle Evolution at Pyrolysis Conditions Considering Shrinkage and Chemical Kinetics with Conjugate Heat Transfer: Yongsuk Cho and Song-Charng Kong; Energy Fuels 2023, 37, 8, 5926–5941 (https://doi.org/10.1021/acs.energyfuels.2c03892)

Abstract

Biomass pyrolysis is an attractive method to produce renewable biofuel in a short time scale. This paper discusses a computational study considering particle shrinkage and reaction kinetics to characterize biomass particle evolution under pyrolysis conditions. A representative elementary volume (REV) scale simulation was conducted in three dimensions to resolve the gas and solid domains. The interface was modeled using the conjugated heat transfer (CHT) and the adapted partially saturated method (PSM) in the lattice Boltzmann (LB) framework. A sufficient gas thickness was considered to simulate the interface physics, such as the thermal boundary layer and product gas outflux. The current simulation was validated using three different experiments. The particle conversion time, temperature, and shrinkage were well predicted. A parametric study investigated the effect of different modeling approaches and operating conditions. Results show that the internal heat transfer is affected by the particle size, inlet gas velocity, reactor temperature, and geometry. The Fourier number decreases to a nearly constant value as the particle size increases. The Péclet number increases linearly with the reactor temperature. Sub-particle scale simulation results reveal that the CHT model and permeability need to be considered when simulating gaseous product efflux out of the biomass particle. Three regimes are identified based on the particle permeability: diffusion-limited, mixed, and advection-limited. The gaseous product efflux delays the overall conversion in the mixed regime. A modified heat transfer coefficient is formulated based on the current numerical study.

Designing Ag@NiO as Air Electrode Catalysts with Synergistic Interface and Doping Engineering Strategies for High-Performance Lithium–Oxygen Batteries: Yan Lu, Yalin Zhou, Xiaoshi Lang, Tan Wang, Tingting Qu, Lan Li, Chuangang Yao, Xindou Yu, Yuhan Teng, and Kedi Cai; Energy Fuels 2023, 37, 8, 6257–6265 (https://doi.org/10.1021/acs.energyfuels.3c00378)

Abstract

Li–O₂ batteries with higher energy density are recognized as promising next-generation energy storage devices. However, sluggish oxygen redox kinetics leads to large overpotential and poor cycle performance which restrict the practical application of Li–O₂ batteries. In this work, we successfully prepare Ag@NiO via the interface and doping synergistic effect engineering strategy as a highly efficient air electrode catalyst to accelerate electrochemical reactions during the oxygen reduction reaction and oxygen evolution reaction procedure in lithium–oxygen batteries. The interface binding between Ag and NiO can be strengthened by generating Ag nanoparticles on the surface of NiO, and the electronic structure can be regulated after doping Ag, which offers more active sites and high conductivity to boost the catalytic activity. Therefore, Ag@NiO as an efficient air electrode catalyst for Li–O⁺₂ batteries exhibits superior electrochemical performance. This means that the interface and doping synergistic effect engineering strategy boosts the oxygen redox kinetics which opens up new paths for highly efficient air electrode catalysts of Li–O₂ batteries.

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives:  Da Song, Yan Lin, Chengyang Li, Shiwen Fang, Fang He, Zhen Huang, Zengli Zhao, Ya Xiong, and Hongyu Huang; Energy Fuels 2023, 37, 8, 5743–5756 (https://doi.org/10.1021/acs.energyfuels.3c00402)

Abstract

Chemical looping technology is one of the most promising approaches in the fields of fuel conversion, pollution removal, energy conservation, and carbon dioxide capture and utilization and has been extensively investigated for more than two decades. A majority of the chemical looping process is achieved through the migration and transformation of lattice oxygen. Thus, exploring the migration and transformation of lattice oxygen is critical to clarify chemical looping’s reaction rules to allow for further control of reaction selectivity and yield. Herein, recent advances in the exploration of lattice oxygen’s migration mechanism are systematically reviewed, with a focus on structure–activity relationships. The great roles that characterization techniques perform to address the challenges in exploring the migration mechanism of lattice oxygen activities are discussed first. We then outline the categories of oxygen carrier materials and the migration mechanism of lattice oxygen. Lastly, the most promising research directions that design high-performance oxygen carriers with well-regulated lattice oxygen activity through the redox reaction mechanism are overviewed. We infer that the research on the relationship between lattice oxygen activity and target products is challenging but essential─it is a direction worthy of our efforts in the future.

Cross-Linked Polymer Composite Electrolyte Incorporated with Waste Seashell Based Nanofiller for Lithium Metal Batteries: Pandurangan Swathi, Sreejith O. V., Thamayanthi Panneerselvam, Ramaswamy Murugan, and Arun Prasath Ramaswamy; Energy Fuels 2023, 37, 8, 6186–6196 (https://doi.org/10.1021/acs.energyfuels.2c04381)

Abstract

The next-generation electric vehicle requires superior safety and high-energy-density batteries for better performance. Currently, solid polymer electrolytes provide better safety, high mechanical stability, and a desirable electrode-to-electrolyte interface in lithium-ion batteries compared to those in conventional battery systems. However, the ionic conductivity of solid-state electrolytes remains challenging at room and low operating temperatures. Herein, we report that incorporating a greener calcium hydroxide (CH) based nanofiller derived from natural waste seashells with polymer electrolyte gives a tremendously increased lithium-ion conductivity of 4.12 × 10^–5 S cm^–1 at 25 °C. The cross-linked composite polymer electrolyte (CCPE) was prepared with PEO, LiClO₄ salt, greener nanofiller, and cross-linking monomers via the facile ultraviolet (UV) polymerization technique. The photosensitive vinyl groups of diacrylate and the thio groups of the tetrathiol monomer undergo a thiol–ene click reaction to form a highly cross-linked network with homogeneously distributed LiClO₄ and CH nanofiller. The incorporation of 15 wt % of CH greener nanofiller significantly improved the amorphous phase of the composite electrolyte and showed a wide electrochemical window of 5 V. The fine porous structure of CH greener nanofiller incorporated in the solid-state cross-linked network electrolyte channelizes for smooth lithium-ion mobility. The fabricated full cell exhibits good discharge capacity, of 160 mAh g^–1 to 150 mAh g^–1 at 0.1 C over 50 cycles with a high Coulombic efficiency of 95 % at 60 °C. Naturally derived, cost-effective greener nanofiller from waste seashells acts as a prominent additive to prepare solid-state electrolytes with high stability in lithium metal batteries.

Carbon-Coated MnO Quantum Dot-Decorated Three-Dimensional Graphene Aerogel Composite for High-Performance Lithium-Ion Batteries: Ran Liu, Xiaoning Zhao, Haibo Zhao, Liang Liang, Shaolei Zhao, and Yiwen Zhang; Energy Fuels 2023, 37, 8, 6240–6247 (https://doi.org/10.1021/acs.energyfuels.3c00350)

Abstract

Herein, carbon-coated MnO QDs decorated on a graphene aerogel (GA, C@MnO QDs/GA) were fabricated by forming a manganese oxide gel in situ on the GA, followed by supercritical drying and carbonization. The composite combines the uniform distribution of ultra-small MnO QDs and the conducting GA with the 3D porous interconnected network structure. The well-dispersed tiny MnO quantum dots can buffer the volume change and shorten the ion diffusion path to improve the reaction kinetics. The GA can provide a 3D conductive channel for rapid electron transfer and Li diffusion. When used as anodes for Li-ion batteries, C@MnO QDs/GA electrodes displayed superior electrochemical performance, such as ultra-high discharge capacity, excellent cycling stability, and outstanding rate performance. A high discharge capacity of 1698 mA h g^+–1 was delivered after 100 cycles at 200 mA g^–1, and a capacity of 702 mA h g^–1 can be retained at a high current density of 2000 mA g^–1. The results suggest that the C@MnO QDs/GA materials designed in this work can be potential anodes for high-performance LIBs, providing meaningful implications for further exploration of oxide anodes for next-generation alkali metal-ion batteries.

Calcite–Fluid Interfacial Tension: H₂ and CO₂ Geological Storage in Carbonates: Mirhasan Hosseini, Muhammad Ali, Jalal Fahimpour, Alireza Keshavarz, and Stefan Iglauer; Energy Fuels 2023, 37, 8, 5986–5994 (https://doi.org/10.1021/acs.energyfuels.3c00399)

Abstract

Underground hydrogen storage (UHS) and CO₂ geological storage (CGS) are two outstanding techniques for meeting the universal energy demand and reducing anthropogenic greenhouse gases (GHGs). In this context, the calcite–fluid interfacial tension (γ_{calcite–fluid}) is a critical parameter for gas s torage in carbonate formations as it affects the spreading and flow of fluids in porous media, gas injection/withdrawal rate, gas storage capacity, and containment safety. However, there is a scarcity of γ_{calcite–fluid} data (e.g., γ_{calcite–gas} and γ_{calcite–water} for carbonate/gas/water systems) at geological conditions in the literature. In addition, there is no independent experimental method to measure γ_rock–fluid; thus, advancing and receding contact angles are often used to calculate it by a combination of Neumann’s equation of state and Young’s equation. We, therefore, theoretically calculated γ_{calcite–fluid} as a function of the main geological parameters, including temperature, pressure, organic acid concentration, and salinity for calcite/H₂/water and calcite/CO₂/water systems. We recognized that γ_{calcite–gas} decreased with pressure, salinity, and organic acid concentration but increased with temperature. Also, a slight increase in γ_{calcite–water} with organic acid concentration and salinity was noticed at 15 MPa, 323.15 K, and 10 MPa, 323.15 K, respectively. However, γ_{calcite–water} slightly decreased with temperature, assuming that it remained constant with pressure. Furthermore, the values of γ_{calcite–fluid} for a H₂/brine system were more than those for a CO₂/brine system. This work thus provides a deep understanding of the wetting characteristics at calcite/H₂/water and calcite/CO₂/water interfaces and leads to a better investigation of H₂/CO₂ storage in carbonate formations.

Review on Thermal Management of Lithium-Ion Batteries for Electric Vehicles: Advances, Challenges, and Outlook: Liange He, Zihan Gu, Yan Zhang, Haodong Jing, and Pengpai Li; Energy Fuels 2023, 37, 7, 4835–4857 (https://doi.org/10.1021/acs.energyfuels.2c04243)

Abstract

Due to strict regulations and the requirement to reduce greenhouse gas emissions, electric vehicles (BEVs) are a promising mode of transportation. The lithium battery is the most important power source for an electric vehicle, but its performance and life are greatly restricted by temperature. To ensure the safety of automobile operation and alleviate mileage anxiety, it is urgent to understand the current situation and predict the development and challenge of battery thermal management system. This work reviews the existing thermal management research in five areas, including cooling and heating methods, modeling optimization, control methods, and thermal management system integration for lithium batteries. Battery thermal management types include air-based, liquid-based, PCM-based, heat-pipe-based, and direct cooling. Designing a better battery thermal management system not only needs to be optimized using algorithms on the model but also it uses intelligent algorithms for precise control to achieve safety and reduce energy consumption. This work also reviews the differences in thermal management systems between square and cylindrical batteries and summarizes the development trend of modularity in battery thermal management systems.

Synergistic Reductive Electrolysis Mixture Additive-Based Dual-Cell Configuration: An Effective Approach for High-Performance Aqueous Aluminum–Air Battery: Siva Palanisamy, Abdul Kareem, Arunkumar Prabhakaran Shyma, Kathavarayan Thenmozhi, Nandhakumar Eswaramoorthy, Vinoth Kumar Ponnusamy, and Sellappan Senthilkumar; Energy Fuels 2023, 37, 7, 5556–5566 (https://doi.org/10.1021/acs.energyfuels.3c00090)

Abstract

Neutral aqueous electrolyte-based aluminum–air (Al–air) batteries have managed to gather significant attention because of their characteristic safety and cost effectiveness. However, the formation of the passivation layer [Al(OH)₃] on the aluminum anode inhibits the long-term shelf life of the battery. Herein, a novel strategy to overturn the passivation by altering the aluminum/electrolyte interface is proposed. Incorporation of synergistic reductive electrolysis mixture additives (Tiron + NaNO₃) can significantly reduce the passivation of the aluminum anode. The efficacy of the Tiron + NaNO₃ synergistic mixture additive has been systematically examined using half-cell and full-cell with different concentrations of the additives in 0.5% NaCl. Furthermore, dual cell performance was investigated with optimum concentration (0.005 M Tiron + 0.005 M NaNO₃) of the additive in 0.5% NaCl as the anolyte and different concentrations of H₂SO₄ as the catholyte. It is found that the resulting pumpless dual cell battery comprising neutral electrolyte with 0.005 M Tiron + 0.005 M NaNO₃ mixture additive as the anolyte and 1 M H₂SO₄ as the catholyte demonstrated a remarkable cell potential of 1.14 V at a current density of 1 mA g^–1, which is closer to the theoretical value. Morphological investigations using optical microscopy studies and X-ray photoelectron spectroscopic investigations also confirmed that the Tiron + NaNO₃ additive is effective in preventing the discharge product on both anode and cathode surfaces and thus resulting in enhanced battery performance.

Research Progress on Synthesis and Adsorption Properties of Porous Composite Adsorbents for Adsorption Cooling and Desalination Systems: A Mini-review: Wenhao Xie, Weisan Hua, and Xuelai Zhang; Energy Fuels 2023, 37, 7, 4751–4768 (https://doi.org/10.1021/acs.energyfuels.2c03700)

Abstract

The adsorption cooling and desalination system is expected to become the mainstream technology of refrigeration and desalination in the future, because it has significant advantages of low temperature driving and low carbon emission. The system based on adsorption technology merits a small environmental impact and low energy consumption, which can help solve the water and energy crises. More importantly, it can use low-grade heat energy to reduce overall carbon emissions in the working process. The adsorbent is the essential component of an adsorption system, and improving the adsorbent is a vital technological advancement for increasing system effectiveness. Porous materials, such as zeolite, silica gel, and metal–organic frameworks, are the most studied adsorption materials in adsorption cooling and desalination systems. They behave differently regarding stability, thermal conductivity, adsorption capacity, and regeneration temperature. The research status of several different adsorbents, such as zeolite, silica gel and metal–organic frameworks, was comprehensively reviewed and compared. In-depth research was done on several composite adsorption materials’ synthesis processes, characterization, and adsorption traits. The obstacles they experienced were then studied, along with the development trend of composite porous adsorbents. The purpose of this study is to provide a reference for researchers committed to developing new adsorption materials under various applications and conditions.

Advances and Perspective of Noble-Metal-Free Nitrogen-Doped Carbon for pH-Universal Oxygen Reduction Reaction Catalysts: Yuyun Irmawati, Bagas Prakoso, Falihah Balqis, Indriyati, Rike Yudianti, Ferry Iskandar, and Afriyanti Sumboja; Energy Fuels 2023, 37, 7, 4858–4877 (https://doi.org/10.1021/acs.energyfuels.2c04272)

Abstract

With the increasing demand for diversification of renewable energy sources, the high activity and stability of electrocatalysts in all pH ranges have been highlighted as one of the future directions in electrochemical energy generation and storage systems. Noble-metal-free nitrogen-doped carbon (M-N/C) has been explored as a substitute for the expensive platinum-based oxygen reduction reaction (ORR) electrocatalysts. However, its ORR activity remains limited to alkaline electrolytes. In acidic medium, its low activity and stability correspond to metallic site dissolution and protonation of N-functional groups, which are even worse in neutral electrolytes because of low ionic conductivity and low H concentration. This review summarizes strategies to improve the stability and activity of M-N/C as pH-universal ORR electrocatalysts. First, the ORR mechanism focusing on active site identification for each pH condition is discussed. Four strategies, including engineering pore structure, adding carbon shell wrapping, and introducing multiple nonmetal dopants and dual metallic active sites on the carbon substrate, are then evaluated to design pH-universal ORR electrocatalysts with distinguished activity and stability. Lastly, future perspectives are given to show the viewpoint of further development and potential applications of M-N/C electrocatalysts.⁺

Polyethylene Oxide/Sodium Sulfonamide Polymethacrylate Blends as Highly Conducting Single-Ion Solid Polymer Electrolytes: Jorge L. Olmedo-Martínez, Asier Fdz De Anastro, María Martínez-Ibañez, Alejandro J. Müller, and David Mecerreyes; Energy Fuels 2023, 37, 7, 5519–5529 (https://doi.org/10.1021/acs.energyfuels.2c04296)

Abstract

In this work, blends of polyethylene oxide (PEO) and poly(sodium 1-[3-(methacryloyloxy) propylsulfonyl]-1-(trifluoromethanesulfonyl) imide) (PNaMTFSI) in different compositions were investigated for their application as solid electrolytes for sodium batteries. PNaMTFSI and PEO are miscible, exhibiting only one T_g in the whole range of compositions. PNaMTFSI was shown to reduce the crystal growth rate of PEO crystals but increase PEO nucleation, making the overall crystallization rate higher in blends with 15 and 30 wt % PNaMTFSI. The ionic conductivity is also affected by the blend composition. The highest values of ionic conductivity were observed with 15 and 30 wt % PNaMTFSI at high temperatures equal to 5.84 × 10^–5 and 7.74 × 10^–5 S cm^–1 at 85 °C, respectively, with values of sodium-ion transference numbers of higher than 0.83 and electrochemical stability between 3.5 and 4.5 V versus Na/Na⁺⁰ depending on the composition, which opens the possibility of its use in sodium batteries. Finally, a comparison was made between the effect of sodium and lithium on these types of electrolytes, showing that sodium electrolytes have a lower ionic conductivity due to the larger size of the Na cation. The differences in the spherulitic growth rate and overall crystallization rate between Li and Na-containing electrolytes were compared and rationalized in terms of the blends’ intermolecular interactions and the relative contribution of primary nucleation and growth.

Low-Cost and Large-Scale Preparation of H₂O and Mg²⁺ Co-Preintercalated Vanadium Oxide with High-Performance Aqueous Zn-Ion Batteries: Xiaoxiao Cui, Hui Liu, Xuena Du, Xianmin Huang, Hongyu Zhao, Ruogu Zheng, Hai Wang, Dai Dang, and Chen Qing; Energy Fuels 2023, 37, 7, 5530–5539 (https://doi.org/10.1021/acs.energyfuels.3c00043)

Abstract

Rechargeable zinc-ion batteries (ZIBs) are considered the most promising energy storage device to replace lithium-ion batteries (LIBs) due to their high security and environment-friendly feature. However, the synthesis of high-performance cathode materials usually requires harsh conditions (such as high temperature and high pressure), which limits the practical application of ZIBs. Herein, a facile large-scale preparation of H₂O and Mg²⁺ co-intercalated vanadium oxide is realized by heating vanadium pentoxide and magnesium sulfate solution in a water bath at low temperature. Through in-depth investigation, it is found that the introduced H₂O and Mg²⁺ not only expand the layer spacing of vanadium pentoxide but also improve the structural stability of V–O layers and ion diffusion. As a result, the obtained product displays an excellent specific capacity of 473 mAh g^–1 at 0.1 A g^–1 and superior cycle performance when used as the cathode material of ZIBs. Such a result indicates that H₂O and Mg²⁺ co-intercalated vanadium oxide shows a good application prospect.

Nano FeSb₂S₄ Anchored on Exfoliated Graphite for Sodium-Ion Battery Anode via a Two-Step Fabrication: Peng Wang, Yihong Ding, Ying Chu, Xinxin Zhu, Jie Lin, Lixiong Shao, and Tianbiao Zeng; Energy Fuels 2023, 37, 7, 5577–5585 (https://doi.org/10.1021/acs.energyfuels.3c00106)

Abstract

FeSb₂S₄ is considered a potential anode material of sodium-ion batteries (SIBs) due to the high theoretical capacity (877 mAh g^–1) and fast Na diffusion kinetics. Synthesis of the FeSb⁺₂S₄-based anode via a simple strategy is essential for practical applications. In this study, nano FeSb₂S₄ anchored on exfoliated graphite (FeSb₂S₄-G) was fabricated via a two-step strategy: heat treatment of commercial FeS+Sb₂S₃ powder and then ball-milling with commercial graphite. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations reveal that the pulverized nano FeSb₂S₄ and exfoliated graphite establish the chemical bonds, which is very advantageous to boost the charge/discharge reversibility. As-prepared FeSb₂S₄-G delivered 577 mAh g^–1 in the second cycle under 100 mA g^–1 and kept 385 mAh g^–1 in the 70th cycle; the cycling stability surpassed bulk FeSb₂S₄ (662 mAh g^–1 in the 2nd cycle, 109 mAh g^–1 in the 70th cycle). Considering only two steps of the synthesis processes, this work presents a viable strategy for fabricating high-performance FeSb₂S₄-based SIB anode materials.

Emerging Exsolution Materials for Diverse Energy Applications: Design, Mechanism, and Future Prospects: Hyeongwon Jeong, Yo Han Kim, Bo-Ram Won, Hyejin Jeon, Chan-ho Park, and Jae-ha Myung; Chem. Mater. 2023, 35, 10, 3745–3764 (https://doi.org/10.1021/acs.chemmater.3c00004)

Abstract

Nanostructured catalytic materials are considered to be a favorable design concept for various energy conversion and storage systems. Nanosized metal catalysts supported on oxide scaffolds have been adopted in numerous fields, including fuel cells, gas sensors, and chemical reforming devices. Nevertheless, nanometal catalysts often suffer from durability issues. Although surface-decorated nanometal catalysts can deliver sufficient catalytic activity, some of them still exhibit durability issues in severe operating environments. Recently, nanocatalysts produced by in situ exsolution have been demonstrated to overcome the practical limitations of conventional nanometal catalysts. The exsolution is defined as a process in which a catalytically active dopant in perovskite oxide is exsolved on its surface as highly dispersed nanometal catalysts. In particular, exsolution nanocatalysts embedded on perovskite oxides exhibit higher nanoparticle densities and greater resistance to particle agglomeration than conventional nanometal catalysts. This Perspective presents an overview of recent advances in exsolution materials for energy applications including fundamental mechanisms, design strategies for host oxides, and practical applications. The future prospects of these materials and the scope for further optimization are also discussed.

Bimetallic Pt–Ni Two-Dimensional Interconnected Networks: Developing Self-Assembled Materials for Transparent Electronics: Pavel Khavlyuk, Andrei Mitrofanov, Volodymyr Shamraienko, René Hübner, Johannes Kresse, Konstantin B. L. Borchert, and Alexander Eychmüller; Chem. Mater.  2023, 35, 7, 2864–2872 (https://doi.org/10.1021/acs.chemmater.2c03707)

Abstract

Continuous advancements in science and technology in the field of flexible devices encourage researchers to dedicate themselves to seeking candidates for new flexible transparent conductive films (FTCFs). Our recently developed two-dimensional (2D) metal aerogels are considered as a new class of FTCFs. Here, we describe a new large-scale self-assembly synthesis of bimetallic Pt–Ni 2D metal aerogels with controllable morphology during the synthesis. The obtained 2D aerogels require only a low quantity of precursors for the synthesis of percolating nanoscale networks with areas of up to 6 cm² without the need of an additional drying step. Stacks of the obtained monolayer structures display low sheet resistances (down to 270 Ω/sq), while decreasing the optical transparency. In perspective, the 2D bimetallic Pt–Ni aerogels not only enrich the structural diversity of metal aerogels but also bring forth new materials for further applications in flexible electronics and electrocatalysis with reduced costs of production.

Room-Temperature CO₂ Hydrogenation to Methanol over Air-Stable hcp-PdMo Intermetallic Catalyst: Hironobu Sugiyama, Masayoshi Miyazaki, Masato Sasase, Masaaki Kitano, and Hideo Hosono; J. Am. Chem. Soc. 2023, 145, 17, 9410–9416 (https://doi.org/10.1021/jacs.2c13801)

Abstract

CO₂ hydrogenation to methanol is one of the most promising routes to CO₂ utilization. However, difficulty in CO₂ activation at low temperature, catalyst stability, catalyst preparation, and product separation are obstacles to the realization of a practical hydrogenation process under mild conditions. Here, we report a PdMo intermetallic catalyst for low-temperature CO₂ hydrogenation. This catalyst can be synthesized by the facile ammonolysis of an oxide precursor and exhibits excellent stability in air and the reaction atmosphere and significantly enhances the catalytic activity for CO₂ hydrogenation to methanol and CO compared with a Pd catalyst. A turnover frequency of 0.15 h^–1 was achieved for methanol synthesis at 0.9 MPa and 25 °C, which is comparable to or higher than that of the state-of-the-art heterogeneous catalysts under higher-pressure conditions (4–5 MPa).

Multivariate Flexible Framework with High Usable Hydrogen Capacity in a Reduced Pressure Swing Process: Arijit Halder, Ryan A. Klein, Sarah Shulda, Gavin A. McCarver, Philip A. Parilla, Hiroyasu urukawa, Craig M. Brown, and C. Michael McGuirk;  J. Am. Chem. Soc. 2023, 145, 14, 8033–8042 (https://doi.org/10.1021/jacs.3c00344)

Abstract

Step-shaped adsorption–desorption of gaseous payloads by flexible metal–organic frameworks can facilitate the delivery of large usable capacities with significantly reduced energetic penalties. This is desirable for the storage, transport, and delivery of H₂, as prototypical adsorbents require large swings in pressure and temperature to achieve usable capacities approaching their total capacities. However, the weak physisorption of H₂ typically necessitates undesirably high pressures to induce the framework phase change. As de novo design of flexible frameworks is exceedingly challenging, the ability to intuitively adapt known frameworks is required. We demonstrate that the multivariate linker approach is a powerful tool for tuning the phase change behavior of flexible frameworks. In this work, 2-methyl-5,6-difluorobenzimidazolate was solvothermally incorporated into the known framework CdIF-13 (sod-Cd(benzimidazolate)₂), resulting in the multivariate framework sod-Cd(benzimidazolate)_1.87(2-methyl-5,6-difluorobenzimidazolate)_0.13 (ratio = 14:1), which exhibited a considerably reduced stepped adsorption threshold pressure while maintaining the desirable adsorption–desorption profile and capacity of CdIF-13. At 77 K, the multivariate framework exhibits stepped H₂ adsorption with saturation below 50 bar and minimal desorption hysteresis at 5 bar. At 87 K, saturation of step-shaped adsorption occurs by 90 bar, with hysteresis closing at 30 bar. These adsorption–desorption profiles enable usable capacities in a mild pressure swing process above 1 mass %, representing 85–92% of the total capacities. This work demonstrates that the desirable performance of flexible frameworks can be readily adapted through the multivariate approach to enable efficient storage and delivery of weakly physisorbing species.

Nucleation and Growth Mode of Solid Electrolyte Interphase in Li-Ion Batteries: Yu-Xing Yao, Jing Wan, Ning-Yan Liang, Chong Yan, Rui Wen, and Qiang Zhang; J. Am. Chem. Soc. 2023, 145, 14, 8001–8006 (https://doi.org/10.1021/jacs.2c13878)

Abstract

The solid electrolyte interphase (SEI) is regarded as the most important yet least understood component in Li-ion batteries. Considerable effort has been devoted to unravelling its chemistry, structure, and ion-transport mechanism; however, the nucleation and growth mode of SEI, which underlies all these properties, remains the missing piece. We quantify the growth mode of two representative SEIs on carbonaceous anodes based on classical nucleation theories and in situ atomic force microscopy imaging. The formation of inorganic SEI obeys the mixed 2D/3D growth model and is highly dependent on overpotential, whereby large overpotential favors 2D growth. Organic SEI strictly follows the 2D instantaneous nucleation and growth model regardless of overpotential and enables perfect epitaxial passivation of electrodes. We further demonstrate the use of large current pulses during battery formation to promote 2D inorganic SEI growth and improve capacity retention. These insights offer the potential to tailor desired interphases at the nanoscale for future electrochemical devices.

Highly Connected Three-Dimensional Covalent Organic Framework with Flu Topology for High-Performance Li-S Batteries: Wenbo Liu, Kang Wang, Xiaoning Zhan, Zhixin Liu, Xiya Yang, Yucheng Jin, Baoqiu Yu, Lei Gong, Hailong Wang, Dongdong Qi, Daqiang Yuan, and Jianzhuang Jiang; J. Am. Chem. Soc. 2023, 145, 14, 8141–8149 (https://doi.org/10.1021/jacs.3c01102)

Abstract

Lithium-sulfur batteries (LSBs) have been considered as a promising candidate for next-generation energy storage devices, which however still suffer from the shuttle effect of the intermediate lithium polysulfides (LiPSs). Covalent-organic frameworks (COFs) have exhibited great potential as sulfur hosts for LSBs to solve such a problem. Herein, a pentiptycene-based D_2h symmetrical octatopic polyaldehyde, 6,13-dimethoxy-2,3,9,10,18,19,24,25-octa(4′-formylphenyl)pentiptycene (DMOPTP), was prepared and utilized as a building block toward preparing COFs. Condensation of DMOPTP with 4-connected tetrakis(4-aminophenyl)methane affords an expanded [8 + 4] connected network 3D-flu-COF, with a flu topology. The non-interpenetrated nature of the flu topology endows 3D-flu-COF with a high Brunauer–Emmett–Teller surface area of 2860 m² g^–1, large octahedral cavities, and cross-linked tunnels in the framework, enabling a high loading capacity of sulfur (∼70 wt %), strong LiPS adsorption capability, and facile ion diffusion. Remarkably, when used as a sulfur host for LSBs, 3D-flu-COF delivers a high capacity of 1249 mA h g^–1 at 0.2 C (1.0 C = 1675 mA g^–1), outstanding rate capability (764 mA h g^–1 at 5.0 C), and excellent stability, representing one of the best results among the thus far reported COF-based sulfur host materials for LSBs and being competitive with the state-of-the-art inorganic host materials.

Highly Stable Iron- and Carbon-Based Electrodes for Li-Ion Batteries: Negative Fading and Fast Charging within 12 Min: Wonyoung Choi, Jaeyun Ha, Yong-Tae Kim, and Jinsub Choi; ChemSusChem 2022, 15, e202201137, Research Article: doi.org/10.1002/cssc.202201137

Abstract

Lithium-ion batteries (LIBs) with high energy density and safety under fast-charging conditions are highly desirable for electric vehicles. However, owing to the growth of Li dendrites, increased temperature at high charging rates, and low specific capacity in commercially available anodes, they cannot meet the market demand. In this study, a facile one-pot electro-chemical self-assembly approach has been developed for constructing hybrid electrodes composed of ultrafine Fe3O4 particles on reduced graphene oxide (Fe3O4@rGO) as anodes for LIBs. The rationally designed Fe3O4@rGO electrode containing 36 wt% rGO exhibits an increase in specific capacity as cycling progresses, owing to improvements in the active sites, electro-chemical kinetics, and catalytic behavior, leading to a high specific capacity of 833 mAhg_1 and outstanding cycling stability over 2000 cycles with a capacity loss of only 0.127% per cycle at 5 Ag_1, enabling the full charging of batteries within 12 min. Furthermore, the origin of this abnormal improvement in the specific capacity (called negative fading), which exceeds the theoretical capacity, is investigated. This study opens up new possibilities for the commercial feasibility of Fe3O4@rGO anodes in fast-charging LIBs.

Bifunctional In Situ Polymerized Interface for Stable LAGP-Based Lithium Metal Batteries: Shengnan Zhang, Zhen Zeng, Wei Zhai, Guangmei Hou, Lina Chen, and Lijie Ci; Adv. Mater. Interfaces 2021, 8, 2100072 (DOI: 10.1002/admi.202100072)

Abstract

All-solid-state lithium metal batteries (ASSLMBs) have attracted intensive research attention since their incomparable energy density and the further advance of ASSLMBs is severely dependent on the development of solid electrolytes. Unfortunately, as one of the most studied solid electrolytes, the practical applications of (NASICON)-type Li 1.5Al0.5Ge0.5P3O12 (LAGP) electrolyte is hindered by not only its inferior interfacial contact with elec – trodes but also its undesirable instability toward Li metal anodes. In this work, a bifunctional in situ formed poly(vinylene carbonate) (PVCA)-based buffer layer is introduced between the LAGP electrolyte and the metallic Li anode to improve interface compatibility and the electrolyte stability . The improved interface contact between LAGP and electrodes and the enhanced stability of LAGP enable ASSLMBs with excellent electrochem – ical performance. The Li/LAGP/Li symmetric cell with the PVCA-based interlayer can maintain a low overpotential of 80 mV for 800 h at 0.05 mA cm–2. Inspiringly, the as-assembled ASSLMBs with LiFePO4 as the cathode also present excellent cyclic stability with a high initial dis – charge capacity of 150 mAh g –1 at 0.5 C and superior capacity retention of 96% after 200 cycles.

In-Built Quasi-Solid-State Poly-Ether Electrolytes Enabling Stable Cycling of High-Voltage and Wide-Temperature Li Metal Batteries Yong Chen, Feng Huo, Shimou Chen, Weibin Cai, and Suojiang Zhang; Adv. Funct. Mater. 2021, 31, 2102347 (DOI: 10.1002/adfm.202102347)

Abstract

Developing solid-state electrolytes with good compatibility for high-voltage cathodes and reliable operation of batteries over a wide-temperature-range are two bottleneck requirements for practical applications of solid-state metal batteries (SSMBs). Here, an in situ quasi solid-state poly-ether electrolyte (SPEE) with a nano-hierarchical design is reported. A solid-eutectic electrolyte is employed on the cathode surface to achieve highly-stable performance in thermodynamic and electrochemical aspects. This performance is mainly due to an improved compatibility in the electrode/ electrolyte interface by nano-hierarchical SPEE and a reinforced interface stability, resulting in superb-cyclic stability in Li||Li symmetric batteries (>4000 h at 1 mA cm−2/1 mAh cm−2; >2000 h at 1 mA cm−2/4 mAh cm−2), which are the same for Na, K, and Zn batteries. The SPEE enables outstanding cycle-stability for wide-temperature operation (15–100 °C) and 4 V-above batteries (Li||LiCoO2 and Li||LiNi0.8Co0.1Mn0.1O2). The work paves the way for development of practical SSMBs that meet the demands for wide-temperature applicability, high-energy density, long lifespan, and mass production.

Synergistic Coupling of Li_6.4La₃Zr_1.4Ta_0.6O₁₂ and Fluoroethylene Carbonate Boosts Electrochemical Performances of Poly(Ethylene Oxide)-Based All-Solid-State Lithium Batteries Lu Zhang, Zhitao Wang, Hu Zhou, Xiaogang Li, Qian Liu, Ping Wang, and Aihua Yuan; ChemElectroChem 2022, 9, e202200641; (https://doi.org/10.1002/celc.202200641)

Abstract

All-solid-state lithium batteries (ASSLBs) with poly(ethylene oxide) (PEO)-based composites solid-state electrolytes have received much attention owing to their higher energy density and better safety compared with conventional liquid electro-lytes. However, ASSLBs with PEO-based solid-state electrolytes generally suffer from severe capacity degradation and interface transfer obstacles during the charge/discharge process. In this work, fluoroethylene carbonate (FEC) is employed as a reducing additive to in-situ form LiF-rich and stable solid-state electrolyte interface (SEI). Benefiting from the integrated advantages of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) and FEC binary additives, the number of lithium-ion transference increases to 0.48, which facilitates the stable cycling of Lij jLi symmetrical batteries over 900 h at 0.1 mAcm_2. The synergistic interplay of LLZTO and FEC constructs a stable LiF-rich SEI film, effectively addressing the interfacial problems caused by lithium dendrites and promoting the transport of Li ions. Therefore, the high ionic conductivity and self-healing anode-electrolyte interface are achieved. This study provides a facile and economical strategy to solve the problem of the lithium-electrolyte interface. It is of great scientific significance for the development of dendrite-free solid-state lithium metal batteries.

Water–Salt Oligomers Enable Supersoluble Electrolytes for High-Performance Aqueous Batteries Shengying Cai, Xingyuan Chu, Chang Liu, Haiwen Lai, Hao Chen, Yanqiu Jiang, Fan Guo, Zhikang Xu, Chunsheng Wang, and Chao Gao; Adv. Mater. 2021, 33, 2007470 (https://doi.org/10.1002/adma.202007470)

Abstract

Aqueous rechargeable batteries are highly safe, low-cost, and environmentally friendly, but restricted by low energy density. One of the most efficient solutions is to improve the concentration of the aqueous electrolytes. However, each salt is limited by its physical solubility, generally below 21–32 mol kg−1 (m). Here, a ZnCl2/ZnBr2/Zn(OAc)2 aqueous electrolyte with a record super-solubility up to 75 m is reported, which breaks through the physical solubility limit. This is attributed to the formation of acetate-capped water–salt oligomers bridged by Br−/Cl−-H and Br−/Cl−/O-Zn2+ interactions. Mass spectrometry indicates that acetate anions containing nonpolarized protons prohibit the overgrowth and precipitation of ionic oligomers. The polymer-like glass transition temperature of such inorganic electrolytes is found at ≈−70 to −60 °C, without the observation of peaks for salt-crystallization and water-freezing from 40 to −80 °C. This supersoluble electrolyte enables high-performance aqueous dual-ion batteries that exhibit a reversible capacity of 605.7 mAh g−1, corresponding to an energy density of 908.5 Wh kg−1, with a coulombic efficiency of 98.07%. In situ X-ray diffraction and Raman technologies reveal that such high ionic concentrations of the supersoluble electrolyte enable a stage-1 intercalation of bromine into macroscopically assembled graphene cathode.

A dendrite free Zn-Fe hybrid redox flow battery for renewable energy storage: C. Balakrishnan Jeena, P. Jose Elsa, P. Peter Moly, K. Jacob Ambily, Vadakkan T. Joy; Energy Storage. 2022;4:e275 (https://doi.org/10.1002/est2.275)

Abstract

About two thirds of global greenhouse emissions is caused by burning of fossil fuels for energy purposes and this has spurred great research interest to develop renewable energy technologies based on wind, solar power, and so on. Redox flow batteries (RFB) are receiving wide attention as scalable energy-storage systems to address the intermittency issues of renewable energy sources. However, for widespread commercialization, the redox flow batteries should be economically viable and environmentally friendly. Zinc based batte-ries are good choice for energy storage devices because zinc is earth abundant and zinc metal has a moderate specific capacity of 820 mA hg_1 and high volu-metric capacity of 5851 mA h cm_3. We herein report a zinc-iron (Zn-Fe) hybrid RFB employing Zn/Zn(II) and Fe(II)/Fe(III) redox couples as positive and negative redox systems, respectively, separated by a self-made anion exchange membrane (AEM). The battery delivers a good discharge voltage of approximately 1.34 V at 25 mA cm_2, with a coulombic efficiency (CE) of 92%, voltage efficiency (VE) of 85% and energy efficiency (EE) of ~78% for 30 charge-discharge cycles. Repeated galvanostatic charge/discharge cycles show no degradation in performance, confirming the excellent stability of the system. A key advancement in the present Zn-Fe hybrid redox flow battery with AEM separator is that no dendrite growth was observed on zinc electrode on repeated charge-discharge cycles, which was the serious drawback of many previously reported zinc based redox flow batteries.

A High-Performance Asymmetric Supercapacitor Based on Tungsten Oxide Nanoplates and Highly Reduced Graphene Oxide Electrodes: Muhammad Ashraf, Syed Shaheen Shah, Ibrahim Khan, Md. Abdul Aziz, Nisar Ullah, Mujeeb Khan, Syed Farooq Adil, Zainab Liaqat, Muhammad Usman, Wolfgang Tremel, and Muhammad Nawaz Tahir; Chem. Eur. J. 2021, 27, 6973 –6984 (doi.org/10.1002/chem.202005156)

Abstract

Tungsten oxide/graphene hybrid materials are at-tractive semiconductors for energy-related applications. Herein, we report an asymmetric supercapacitor (ASC, HRG// m-WO₃ ASC), fabricated from monoclinic tungsten oxide (m- WO₃) nanoplates as a negative electrode and highly reduced graphene oxide (HRG) as a positive electrode material. The supercapacitor performance of the prepared electrodes was evaluated in an aqueous electrolyte (1_M H₂SO₄) using three-and two-electrode systems. The HRG//m-WO₃ ASC exhibits a maximum specific capacitance of 389 Fg_1 at a current den-sity of 0.5 Ag_1, with an associated high energy density of 93 Whkg_1 at a power density of 500 Wkg_1 in a wide 1.6 V operating potential window. In addition, the HRG//m-WO₃ ASC displays long-term cycling stability, maintaining 92% of the original specific capacitance after 5000 galvanostatic charge–discharge cycles. The m-WO₃ nanoplates were pre-pared hydrothermally while HRG was synthesized by a modified Hummers method.

Thermodynamic Characterization of Gas Mixtures for Non-Thermal Plasma CO₂ Conversion Applications with Soft-SAFT: Cristina Mas-Peiro, Héctor Quinteros-Lama, Josep Oriol Pou, and Fèlix Llovell;  J. Chem. Eng. Data 2023, 68, 6, 1376–1387 (https://doi.org/10.1021/acs.jced.3c00131)

Abstract

Carbon dioxide (CO₂) transformation into added-value products through non-thermal plasma (NTP) represents a novel technology of interest. The process involves, apart from CO₂, mixtures of different gases such as carbon monoxide (CO), oxygen (O₂), nitrogen (N₂), argon (Ar), and hydrogen (H₂) for subsequent CO₂ methanation. In this work, a preliminary study of the thermodynamic representation of the mixtures relevant in the context of carbon capture, utilization, and storage (CCUS) processes, but focused on the NTP conversion, is presented. The thermodynamic characterization is achieved through the application of the polar soft-statistical associating fluid theory (SAFT) equation of state (EoS), which allows molecular parameterization of pure compounds and the description of mixtures at different conditions of temperature and pressure. An accurate parametrization of all gases is carried out by explicitly considering the quadrupolar nature of CO₂, CO, and N₂. The characterization is then used to describe several single-phase densities, derivative properties, second virial coefficients, and the vapor–liquid equilibrium (VLE) of CO₂ binary mixtures with Ar, O₂, CO, N₂, and H₂, as well as combinations between some of these gases. A parametric analysis of the impact of the binary parameters on the equilibria description is carried out to assess the temperature dependency. The results have overall shown good agreement to experimental data in most conditions using one or two binary parameters. Finally, ternary systems involving CO₂, O₂, Ar, and N₂ have been predicted in good agreement with the experimental data, demonstrating the capacity of the model to evaluate the behavior of multicomponent gas mixtures.

Alloying Strategy for High-Performance Zinc Metal Anodes: Ruotong Li, Yingxiao Du, Yuehua Li, Zhangxing He, Lei Dai, Ling Wang, Xianwen Wu, jiujun Zhang, and Jin Yi; ACS Energy Lett. 2023, 8, 1, 457–476 (https://doi.org/10.1021/acsenergylett.2c01960)

Abstract

Owing to the advantages of low cost, high energy density, and environment friendly, aqueous zinc ion batteries (AZIBs) are considered as promising energy storage devices. Inevitable zinc dendrites, corrosion, passivation, and hydrogen evolution reactions of zinc anodes have seriously hampered the practical application of AZIBs. To address the above-mentioned issues, zinc anode alloying is proposed as an emerging modification strategy. Therefore, it is essential to systematically summarize the obtained research results on zinc alloying strategies and analyze new perspectives. Based on the presented studies on zinc alloying anode, different improvement mechanisms are described, such as an artificial interface alloy protective layer, an electrostatic shielding effect, heterogeneous seeds as zincophilic sites, vertical plane matching strategy, etc. According to the different synthesis methods and mechanisms of action, recent advances have been summarized. Finally, the potential development prospects for further upgrading the alloying of zinc anodes are presented.

Towards Commercialization of Graphite as an Anode for Na-ion Batteries: Evolution, Virtues, and Snags of Solvent Cointercalation: Krishnan Subramanyan and Vanchiappan Aravindan; ACS Energy Lett. 2023, 8, 1, 436–446 (https://doi.org/10.1021/acsenergylett.2c02295)

Abstract

Sodium-ion storage in graphite through a solvent cointercalation mechanism is extremely robust regarding cycling stability, rate performance, and Coulombic efficiency. The graphite half cell has a low working voltage and high power density. The respectable capacity, even at high current rates, makes graphite in a glyme-based system a versatile energy storage device. This perspective comprehensively looks at graphite-based sodium-ion full cells and how they perform. Electrolyte composition, cathode working voltage, irreversibility, precycling, and high current performance are the key points to consider during full-cell fabrication. Some general factors to consider during the full-cell assembly are put forward in this perspective.

A Highly Reversible Low-Cost Aqueous Sulfur–Manganese Redox Flow Battery: Jiafeng Lei, Jiafeng Lei, Yanxin Yao, Yaqin Huang, and Yi-Chun Lu; ACS Energy Lett. 2023, 8, 1, 429–435 (https://doi.org/10.1021/acsenergylett.2c02524)

Abstract

Redox flow batteries are promising energy storage technologies. Low-cost electrolytes are the prerequisites for large-scale energy storage applications. Herein, we describe an ultra-low-cost sulfur–manganese (S–Mn) redox flow battery coupling a Mn²⁺/MnO₂(s) posolyte and polysulfide negolyte. In addition to the intrinsically low cost active materials, the polysulfide negolyte removes the long-unresolved metal dendrite issue of metal–Mn batteries (e.g., Zn–Mn²⁺/MnO₂(s) batteries), enabling substantially improved cycling stability at a high areal capacity (50–100 mAh cm^–2). Due to the low cost of both sulfur and manganese species, this system promises an ultralow electrolyte cost of $11.00 kWh^–1 (based on achieved capacity). This work broadens the horizons of aqueous manganese-based batteries beyond metal–manganese chemistry and offers a practical route for low-cost and long-duration energy storage applications.

Aqueous Colloid Flow Batteries Based on Redox-Reversible Polyoxometalate Clusters and Size-Exclusive Membranes: Yuzhu Liu, Ge-Hua Wen, Junchuan Liang, Song-Song Bao, Jie Wei, Huaizhu Wang, Pengbo Zhang, Mengfei Zhu, Qingqing Jia, Jing Ma, Li-Min Zheng, and Zhong Jin; ACS Energy Lett. 2023, 8, 1, 387–397 (https://doi.org/10.1021/acsenergylett.2c02121)

Abstract

Aqueous redox flow batteries (ARFBs) exhibit great potential for large-scale energy storage, but the cross-contamination, limited ion conductivity, and high costs of ion-exchange membranes restrict the wide application of ARFBs. Herein, we report the construction of aqueous colloid flow batteries (ACFBs) based on redox-active polyoxometalate (POM) colloid electrolytes and size-exclusive membrane separators. The aqueous suspensions of POM clusters, such as [N(C₃H₇)₄]₄[H₁₂(VO₂)₁₂(C₆H₅PO₃)₈]·xH₂O and [N(C₃H₇)₄]₄[H₁₂(VO₂)₁₂(4-FC₆H₄PO₃)₈]·xH₂O, deliver good reversibility, high redox kinetics, and long cycling life. The nanoscale sizes of POM clusters make them compatible with cheap commercial dialysis membrane separators to replace expensive ion-exchange membranes, thus inhibiting the cross-contamination of active species via size exclusion. The ACFBs achieve a high energy efficiency of ∼90% and an ultralow capacity fade rate of 0.004% per cycle. This work highlights the great potential of ACFBs based on redox-reversible POM clusters and size-exclusion membrane separators toward grid-scale and sustainable energy storage applications.

Regulating Zn(002) Deposition toward Long Cycle Life for Zn Metal Batteries: Zhimei Huang, Zezhuo Li, Yueda Wang, Jianlong Cong, Xiaolong Wu, Xiaohui Song, Yongxin Ma, Hongfa Xiang, and Yunhui Huang; ACS Energy Lett. 2023, 8, 1, 372–380 (https://doi.org/10.1021/acsenergylett.2c02359)

Abstract

Regulating the Zn deposition orientation is an efficient way to suppress Zn dendrites and stabilize Zn anodes in aqueous Zn ion batteries (ZIBs). Few studies have been conducted to control Zn(002) deposition by altering the Zn²⁺ solvation structure with a cosolvent. Herein, the bifunctional high-polarity cosolvent hexamethylphosphoramide (HMPA) is proposed in an aqueous electrolyte. It not only suppresses the H₂ evolution reaction via the reshaped Zn²⁺ solvation structure with decreased H₂O activity but also induces Zn(002) deposition with a hexagonal-close-packed morphology due to the strong absorption ability of HMPA to Zn(002). With the optimized electrolyte, Zn dendrites and the HER are suppressed and an ultralong cycle life of 1500 cycles with 99.6% Coulombic efficiency is achieved in Zn||Cu cells. Zn||NH₄V₅O₁₀ and Zn||polyaniline full cells exhibit improved cycling performances compared to that of the bare electrolyte. Our finding provides a feasible and promising way to stabilize Zn anodes and promote the commercial application of ZIBs.

Interphases and Electrode Crosstalk Dictate the Thermal Stability of Solid-State Batteries: Bairav S. Vishnugopi, Md Toukir Hasan, Hanwei Zhou, and Partha P. Mukherjee; ACS Energy Lett. 2023, 8, 1, 398–407 (https://doi.org/10.1021/acsenergylett.2c02443)

Abstract

Solid-state batteries, because of their high energy density, are promising candidates for long-range electric vehicles and electric aviation. While the enhanced safety potential of solid-state batteries has been typically ascribed to the nonflammability of solid electrolytes, an extensive interrogation of their thermal stability is still required. In this work, we reveal how the thermal stability in sulfide-based solid-state batteries is critically dependent on the interphase interactions at the solid electrolyte/Li interface, thereby illustrating the drastically different thermal signature of Li₁₀SnP₂S₁₂ when compared with Li₃PS₄ and Li₆PS₅Cl. Our study shows that thermal runaway occurs even for a pristine Li₁₀SnP₂S₁₂/Li interface and is severely exacerbated with cycling, which exhibits a massive thermal spike at the melting point of Li; this shift in thermal response uniquely correlates to the Li₁₀SnP₂S₁₂ interphase evolution. On the basis of these distinct thermal signatures, cell-level mechanistic safety maps cognizant of the Li/interphase interaction, cathode/Li crosstalk, and specific energy are delineated.

Zero-Gap Electrochemical CO₂ Reduction Cells: Challenges and Operational Strategies for Prevention of Salt Precipitation: Mark Sassenburg, Maria Kelly, Siddhartha Subramanian, Wilson A. Smith, and Thomas Burdyny; ACS Energy Lett. 2023, 8, 1, 321–331 (https://doi.org/10.1021/acsenergylett.2c01885)

Abstract

Salt precipitation is a problem in electrochemical CO₂ reduction electrolyzers that limits their long-term durability and industrial applicability by reducing the active area, causing flooding and hindering gas transport. Salt crystals form when hydroxide generation from electrochemical reactions interacts homogeneously with CO₂ to generate substantial quantities of carbonate. In the presence of sufficient electrolyte cations, the solubility limits of these species are reached, resulting in “salting out” conditions in cathode compartments. Detrimental salt precipitation is regularly observed in zero-gap membrane electrode assemblies, especially when operated at high current densities. This Perspective briefly discusses the mechanisms for salt formation, and recently reported strategies for preventing or reversing salt formation in zero-gap CO₂ reduction membrane electrode assemblies. We link these approaches to the solubility limit of potassium carbonate within the electrolyzer and describe how each strategy separately manipulates water, potassium, and carbonate concentrations to prevent (or mitigate) salt formation.

Elementary Decomposition Mechanisms of Lithium Hexafluorophosphate in Battery Electrolytes and Interphases: Evan Walter Clark Spotte-Smith, Thea Bee Petrocelli, Hetal D. Patel, Samuel M. Blau, and Kristin A. Persson; ACS Energy Lett. 2023, 8, 1, 347–355 (https://doi.org/10.1021/acsenergylett.2c02351)

Abstract

Electrolyte decomposition constitutes an outstanding challenge to long-life Li-ion batteries (LIBs) as well as emergent energy storage technologies, contributing to protection via solid electrolyte interphase (SEI) formation and irreversible capacity loss over a battery’s life. Major strides have been made to understand the breakdown of common LIB solvents; however, salt decomposition mechanisms remain elusive. In this work, we use density functional theory to explain the decomposition of lithium hexafluorophosphate (LiPF₆) salt under SEI formation conditions. Our results suggest that LiPF₆ forms POF₃ primarily through rapid chemical reactions with Li₂CO₃, while hydrolysis should be kinetically limited at moderate temperatures. We further identify selectivity in the proposed autocatalysis of POF₃, finding that POF₃ preferentially reacts with highly anionic oxygens. These results provide a means of interphase design in LIBs, indicating that LiPF₆ reactivity may be controlled by varying the abundance or distribution of inorganic carbonate species or by limiting the transport of PF₆^– through the SEI.

3D-Printed Porous Thermoelectrics for In Situ Energy Harvesting: Danwei Zhang, Xiu Jun Genevieve Lim, Xinwei Li, Kivanc Saglik, Samantha Faye Duran Solco, Xian Yi Tan, Yihao Leow, Wei Zhai, Chee Kiang Ivan Tan, Jianwei Xu, and Ady Suwardi; ACS Energy Lett. 2023, 8, 1, 332–338  (https://doi.org/10.1021/acsenergylett.2c02425)

Abstract

The rapid growth of industrialization has resulted in an tremendous increase in energy demands. The vast amount of untapped waste heat found in factories and power plants can be harnessed to power devices. Thermoelectric materials enable a clean conversion of heat to electrical energy and vice versa, without the need for moving parts. However, existing thermoelectric generators are limited to capturing heat from exterior surfaces. Additive manufacturing offers itself as a cost-effective process that produces complex parts which can recover waste heat from direct heat flows. Herein, we report the first ever in situ energy harvester through porous 3D thermoelectrics. Complex 3D-printed Bi_0.5Sb_1.5Te₃ open cellular structures of high specific surface area are fabricated to allow a high rate of heat transfer throughout the heat pipes with negligible effect on the liquid flow. This work opens up exciting possibilities of energy harvesting from natural self-sustaining thermal gradients found in exhaust pipes and heat exchangers.

Seasonal Fluctuations in Nitrate Levels Can Trigger Lead Solder Corrosion Problems in Drinking Water: Kathryn G. Lopez, Jinghua Xiao, Christopher Crockett, Christian Lytle, Haley Grubbs, and Marc Edwards;  Environ. Sci. Technol. Lett. 2023, 10, 1, 21–26 (https://doi.org/10.1021/acs.estlett.2c00581)

Abstract

After a utility switched its source water from ground to surface water in 2017, first draw water lead levels spiked due to increased lead solder corrosion that could not be explained by existing knowledge. When lead release was not adequately reduced with a 90:10 orthophosphate/polyphosphate corrosion inhibitor blend or even high levels of 100% orthophosphate, an in-depth investigation of possible causes revealed a strong correlation between 90th percentile lead and seasonal fluctuations in surface water nitrate levels. Complementary bench-scale studies that tested new copper coupons with lead solder and harvested pipes from a worst case home verified a strong relationship between nitrate and elevated lead. Lead release in the presence of nitrate became increasingly erratic with time, resulting in the spalling of large lead solder particulates up to 7 mm in length into the water. Lead levels were occasionally >1000 ppb in homes and >100000 ppb in the bench experiments with harvested pipe. Orthophosphate was unable to sufficiently reduce lead levels below the action level during periods with high nitrate levels in the bench studies. Water utilities and regulators should proactively consider possible unintended consequences of higher nitrate levels on lead release when changing source waters or during seasonal runoff events.

Selective Extraction of Silver and Palladium in Leachate Based on EDTA Complexation: Electrodeposition, Nucleation Mechanism, and Kinetic Analysis: Ya Liu, Qingming Song, and Zhenming Xu;  ACS Sustainable Chem. Eng. 2022, 10, 50, 16647–16656 (https://doi.org/10.1021/acssuschemeng.2c04479)

Abstract

The development of green recycling technology for precious metals such as Ag and Pd from secondary resources can prevent environmental pollution caused by improper disposal, and it can alleviate resource shortage and promote sustainable development. Ag and Pd often coexist in some solid waste. This study proposed the extraction of Ag and Pd stepwise from leachate through the green technology of potential-controlled electrodeposition, and the reduction potential difference of Ag and Pd in solution was increased based on EDTA (ethylenediaminetetraacetic acid) complexation. The electrochemical behavior of Ag and Pd⁺²⁺ in solution was investigated. It was determined that the electrodeposition separation of Ag and Pd⁺²⁺ can be achieved with a pH of 9 and an EDTA molar ratio of 1:1.5 in the solution. With sequential electrodeposition at 0 V and −0.7 V, 99.3% of Ag and 96.15% of Pd were recovered, respectively, and their purity was achieved 100%. Pd electrodeposition conformed to three-dimensional instantaneous nucleation and growth mechanism analyzed with the Scharifker–Hills model. Compared with the EDTA-free environment, the diffusion coefficient of ions reduced, and the activation energy of Ag and Pd reduction reaction increased in the EDTA environment. This study provides an environmentally friendly and efficient method for precious metal recovery from secondary resources.

Density Functional Simulation of Adsorption Behavior within the Dicalcium Silicate-Accelerated Carbonation System: Meicheng Zhao, Meijuan Rao, Fazhou Wang, Yong Tao, and Linnu Lu; ACS Sustainable Chem. Eng. 2022, 10, 50, 16825–16832 (https://doi.org/10.1021/acssuschemeng.2c05321)

Abstract

In this study, the adsorption behavior of various molecules, including H₂O, CO₂, and H₂CO₃, on the C₂S surface in the carbonation system was systematically compared to elucidate the microscopic mechanism in early accelerated carbonation using density functional theory and ab initio molecular dynamics. The electronic structures on β-C₂S and γ-C₂S surfaces differ, in that the valence band maximum is contributed by the O p orbital and Ca s orbital, respectively. This difference results in different proton–surface interactions. The protons hydroxylated the [SiO₄]^4– tetrahedra on the β-C₂S surface. On the γ-C₂S surface, the protons enter the interior surface to form a three-coordination configuration with Ca atoms in addition to bonding with the [SiO₄]^4– tetrahedra. The adsorption energy for the dissociative adsorption of H₂CO₃ on both β-C₂S and γ-C₂S surfaces is significantly higher than that of H₂O, and the dissociative adsorption configurations are also more stable. CO₂ only has a strong adsorption tendency on the γ-C₂S surface, where it acquires electrons from the surface Ca atoms to become activated. In the molecular adsorption phase, γ-C₂S interacts more strongly with CO₂, H₂CO₃, and its dissociation products.

Structure-Dependent Surface Molecule-Modified Semiconductor Photocatalysts: Recent Progress and Future Challenges: Yanan Liu, Haiyang Guo, Mengyuan Yu, Congcong Shen, and An-Wu Xu;  ACS Sustainable Chem. Eng. 2022, 10, 50, 16476–16502 (https://doi.org/10.1021/acssuschemeng.2c05634)

Abstract

For the photocatalytic process, the development of efficient photocatalysts is a key and important issue. In recent progress, grafting molecules on the surface of semiconductors via coordination chemistry has received increasing attention owing to its unique advantages. The molecules in molecule-modified semiconductor photocatalysts exhibit three main specific functions, that is, enhancing the light absorption capacity, accelerating charges transfer and improving the surface reaction kinetics; and the regulable structure of molecule has an essential impact on the above functions. In this review, a general introduction to the photocatalysis phenomenon, evaluation and construction of photocatalysts is given first. Then, the type of molecules is introduced; the case studies in typical applications of photocatalytic hydrogen evolution, pollutants removal and carbon dioxide reduction are addressed, focusing on the fabrication, photocatalytic performance and structure–function relationship. In the last section, the underlying challenges and opportunities in future research for molecule-modified photocatalysts are addressed and concluded.

Wedge-Shaped Hopper Design for Milled Woody Biomass Flow: Yimin Lu, Wencheng Jin, Nepu Saha, Jordan Lee Klinger, Yidong Xia, and Sheng Dai; ACS Sustainable Chem. Eng. 2022, 10, 50, 16803–16813 (https://doi.org/10.1021/acssuschemeng.2c05284)

Abstract

The bioenergy industry has been challenged by unstable flow and transport of milled biomass in material handling operations. Handling issues such as hopper clogging and auger jamming are attributed to knowledge gaps between existing handling units designed for bulk solids and their suitability for milled biomass with high compressibility. This work investigates various flow behaviors of granular woody biomass in wedge-shaped hoppers. Hopper flow physical experiments and numerical simulations are conducted to study the influence of the critical material attributes and critical processing parameters on the flow pattern, arching, and throughput. The results show that (1) the preferred flow pattern, mass flow, can be achieved by controlling the material’s internal friction angle, hopper inclination, and hopper wall friction; (2) hopper arching, governed by the competing gravity-driven force against flow resistance from material internal friction and material–wall friction, can be controlled by the hopper wall friction angle and the inclination angle; and (3) flow throughput can be accurately estimated from our empirical equation with inputs of hopper outlet geometry and particle-scale to bulk-scale material attributes. This study elucidates woody biomass flow physics and provides guidance for industrial equipment design.

Combustion of Salicornia bigelovii Pyrolysis Bio-oil and Surrogate Mixtures: Experimental and Kinetic Study: Ribhu Gautam, Shashank S. Nagaraja, Sultan Alturkistani, Yitong Zhai, Can Shao, Mohammed Albaqshi, Gabriele M. Fiene, Mark Tester, and S. Mani Sarathy; Energy Fuels 2023, 37, 1, 385–400 (https://doi.org/10.1021/acs.energyfuels.2c02769)

Abstract

Pyrolysis bio-oil (PBO), a renewable and sustainable alternative energy source, is gaining significant importance. PBOs are polar, viscous, and acidic in nature, which restrict their direct utilization. The blending of PBOs with fossil-based fuels in combustion processes can potentially reduce net carbon emissions. The utilization of PBOs in combustion systems warrants an understanding of their combustion chemistry, which serves as the motivation for this study. In this study, pyrolysis of a saltwater halophyte, Salicornia bigelovii, was performed to obtain PBO. Based on the PBO composition, a blend of pyrrole, furfural, and toluene was prepared as a surrogate. The combustion chemistry of a three-component surrogate comprising oxygen- and nitrogen-containing compounds is studied for the first time. To understand the gas-phase combustion chemistry of the PBO surrogate, experiments were performed in a jet-stirred reactor (JSR) at atmospheric pressure and a residence time of 2 s in the temperature range of 780–960 K (ϕ = 0.25). Also, the PBO surrogate was blended in the ratios of 10 and 20% (by wt) with a toluene/iso-octane (80/20 mol/mol) mixture and investigated to mimic the combustion of PBO with hydrocarbons. A detailed chemical kinetic mechanism was compiled using different sub-mechanisms for surrogate components. NUIGMech1.2 was used as the base mechanism. Fuel-reactant species and 17 product species were identified to understand the combustion chemistry of PBO surrogate and its blends. Furthermore, rate of production analysis was performed to understand the pathways vital for forming intermediates. In addition, the thermal stability of PBO was studied in a thermogravimetric analyzer in the temperature range of 105–750 °C in oxygen and nitrogen atmospheres. The mass loss and derivative mass loss profiles were acquired, different stages of the reactions were identified under the oxygen atmosphere, and the apparent kinetic parameters were determined via the Friedman method.

Sustainable and Flexible Energy Storage Devices: A Review: Dawid Kasprzak, Carmen C. Mayorga-Martinez, and Martin Pumera; Energy Fuels 2023, 37, 1, 74–97 (https://doi.org/10.1021/acs.energyfuels.2c03217)

Abstract

In recent years, the growing demand for increasingly advanced wearable electronic gadgets has been commonly observed. Modern society is constantly expecting a noticeable development in terms of smart functions, long-term stability, and long-time outdoor operation of portable devices. Excellent flexibility, lightweight nature, and environmental friendliness are no less important aspects of the choice of mobile electronics. Naturally, electronic devices need efficient portable power sources (batteries and supercapacitors) that meet the above-mentioned requirements. However, most of these power sources use plastic substrates for their manufacture. Hence, this review is focused on research attempts to shift energy storage materials toward sustainable and flexible components. We would like to introduce recent scientific achievements in the application of noncellulosic polysaccharides for flexible electrochemical energy storage devices as constituents in composite materials for both batteries and supercapacitors. In this review, we will summarize the introduction of biopolymers for portable power sources as components to provide sustainable as well as flexible substrates, a scaffold of current collectors, electrode binders, gel electrolyte matrices, separators, or binding scaffolds for whole devices.

Carbon Storage through Rapid Conversion of Forsterite into Solid Oxalate Phases: Roni Grayevsky, Amit G. Reiss, and Simon Emmanuel; Energy Fuels 2023, 37, 1, 509–517 (https://doi.org/10.1021/acs.energyfuels.2c03245)

Abstract

Carbon capture and storage are likely to be critical components in lowering atmospheric CO₂ levels. Mineralization is often proposed as a method to store carbon and typically involves reacting CO₂ directly with silicate minerals, such as forsterite, to form carbonate minerals. However, this reaction is slow under standard conditions, so that sequestering significant amounts of carbon can take years or decades. Here, we demonstrate the feasibility of using a reaction between oxalic acid and forsterite to create stable carbon-bearing oxalate minerals. We performed a series of batch experiments at room temperature and pressure to quantify the forsterite dissolution rate and the efficiency of Mg utilization. Our results show that conversion of forsterite to Mg and Fe oxalate is achieved rapidly: after 30 days, 52% of Mg was converted to Mg oxalate so that 1 t of forsterite can be used to store 177 kg of carbon. Our calculations show that reacting ultramafic mine tailings with oxalic acid has the potential to make a significant contribution toward the global target for CO₂ removal by carbon capture and storage.

Silicon Nitride, a Close to Ideal Ceramic Material for Medical Application: Robert B. Heimann; Ceramics 2021, 4(2), 208-223 (https://doi.org/10.3390/ceramics4020016)

Abstract

This topical review describes the salient results of recent research on silicon nitride, a ceramic material with unique properties. The outcome of this ongoing research strongly encourages the use of monolithic silicon nitride and coatings as contemporary and future biomaterial for a variety of medical applications. Crystallographic structure, the synthesis and processing of monolithic structures and coatings, as well as examples of their medical applications that relate to spinal, orthopedic and dental implants, bone grafts and scaffolds, platforms for intelligent synthetic neural circuits, antibacterial and antiviral particles and coatings, optical biosensors, and nano-photonic waveguides for sophisticated medical diagnostic devices are all covered in the research reviewed herein. The examples provided convincingly show that silicon nitride is destined to become a leader to replace titanium and other entrenched biomaterials in many fields of medicine.