Bimetal-Organic Framework Nanoboxes Enable Accelerated Redox Kinetics and Polysulfide Trapping for Lithium-Sulfur Batteries

Lithium-sulfur (Li−S) batteries are considered as promising candidates for next-generation energy storage systems in view of the high theoretical energy density and low cost of sulfur resources. The suppression of polysulfide diffusion and promotion of redox kinetics are the main challenges for Li−S batteries. Herein, we design and prepare a novel type of ZnCo-based bimetallic metal–organic framework nanoboxes (ZnCo-MOF NBs) to serve as a functional sulfur host for Li−S batteries. The hollow architecture of ZnCo-MOF NBs can ensure fast charge transfer, improved sulfur utilization, and effective confinement of lithium polysulfides (LiPSs). The atomically dispersed Co−O₄ sites in ZnCo-MOF NBs can firmly capture LiPSs and electrocatalytically accelerate their conversion kinetics. Benefiting from the multiple structural advantages, the ZnCo-MOF/S cathode shows high reversible capacity, impressive rate capability, and prolonged cycling performance for 300 cycles.     

Six-Electron-Redox Iodine Electrodes for High-Energy Aqueous Batteries

Iodine (I₂) shows great promising as the active material in aqueous batteries due to its distinctive merits of high abundance in ocean and low cost. However, in conventional aqueous I₂-based batteries, the energy storage mechanism of I⁻/I₂ conversion is only two-electron redox reaction, limiting their energy density. Herein, six-electron redox chemistry of I₂ electrodes is achieved via the synergistic effect of redox-ion charge-carriers and halide ions in electrolytes. The redox-active Cu²⁺ ions in electrolytes induce the conversion between Cu²⁺ ions and I₂ to CuI at low potential. Simultaneously, the Cl⁻ ions in electrolytes activate the I₂/ICl redox couple at high potential. As a result, in our case, I₂-based battery system with six-electron redox is developed. Such energy storage mechanism with six-electron redox leads to high discharge potential and capacity, excellent rate capability, as well as stable cycling behavior of I₂ electrodes. Impressively, six-electron-redox I₂ cathodes can match various aqueous metal (e.g. Zn, Mn and Fe) anodes to construct metal||I₂ hybrid batteries. These hybrid batteries not only deliver enhanced capacities, but also exhibit higher operate voltages, which contributes to superior energy densities. Therefore, this work broadens the horizon for the design of high-energy aqueous I₂-based batteries.     

Large Interlayer Distance and Heteroatom-Doping of Graphite Provide New Insights into the Dual-Ion Storage Mechanism in Dual-Carbon Batteries

Dual-ion batteries (DIBs) is a promising technology for large-scale energy storage. However, it is still questionable how material structures affect the anion storage behavior. In this paper, we synthesis graphite with an ultra-large interlayer distance and heteroatomic doping to systematically investigate the combined effects on DIBs. The large interlayer distance of 0.51 nm provides more space for anion storage, while the doping of the heteroatoms reduces the energy barriers for anion intercalation and migration and enhances rapid ionic storage at interfaces simultaneously. Based on the synergistic effects, the DIBs composed of carbon cathode and lithium anode afford ultra-high capacity of 240 mAh g⁻¹ at current density of 100 mA g⁻¹. Dual-carbon batteries (DCBs) using the graphite as both of cathode and anode steadily cycle 2400 times at current density of 1 A g⁻¹. Hence, this work provides a reference to the strategy of material designs of DIBs and DCBs.     

Advanced Current Collectors for Alkali Metal Anodes

High-energy-density batteries are in urgent need to solve the ever-increasing energy storage demand for portable electronic devices, electric vehicles, and renewable solar and wind energy systems. Alkali metals, typically lithium(Li), sodium(Na) and potassium(K), are considered as the promising anode materials owing to their low electrochemical potential, low density, and high theoretical gravimetric capacities. However, the problem of dendrite growth of alkali metals during their plating/stripping process will lead to low Coulombic efficiencies, a short lifespan and huge volume expansion, eventually hindering their practical commercialization. To resolve this issue, a very effective approach is engineering the anodes on structured current collectors. This review summarizes the development of the alkali metal batteries and discusses the recent advances in rational design of anode current collectors. First, the challenges and strategies of suppressing alkali-metal dendrite growth are presented. Then the special attention is paid to the novel current collector design for dendrite-free alkali metal anodes. Finally, we give conclusions and perspective on the current challenges and future research directions toward advanced anode current collectors for alkali metal batteries.     

Electrolyte Regulation towards Stable Lithium‐Metal Anodes in Lithium–Sulfur Batteries with Sulfurized Polyacrylonitrile Cathodes

Lithium–sulfur (Li–S) batteries are highly regarded as the next‐generation energy‐storage devices because of their ultrahigh theoretical energy density of 2600 Wh kg^?1. Sulfurized polyacrylonitrile (SPAN) is considered a promising sulfur cathode to substitute carbon/sulfur (C/S) composites to afford higher Coulombic efficiency, improved cycling stability, and potential high‐energy‐density Li–SPAN batteries. However, the instability of the Li‐metal anode threatens the performances of Li–SPAN batteries bringing limited lifespan and safety hazards. Li‐metal can react with most kinds of electrolyte to generate a protective solid electrolyte interphase (SEI), electrolyte regulation is a widely accepted strategy to protect Li‐metal anodes in rechargeable batteries. Herein, the basic principles and current challenges of Li–SPAN batteries are addressed. Recent advances on electrolyte regulation towards stable Li‐metal anodes in Li–SPAN batteries are summarized to suggest design strategies of solvents, lithium salts, additives, and gel electrolyte. Finally, prospects for future electrolyte design and Li anode protection in Li–SPAN batteries are discussed.     

An Organodiselenide Comediator to Facilitate Sulfur Redox Kinetics in Lithium–Sulfur Batteries with Encapsulating Lithium Polysulfide Electrolyte

Lithium–sulfur (Li–S) batteries are regarded as promising high-energy-density energy storage devices. However, the cycling stability of Li–S batteries is restricted by the parasitic reactions between Li metal anodes and soluble lithium polysulfides (LiPSs). Encapsulating LiPS electrolyte (EPSE) can efficiently suppress the parasitic reactions but inevitably sacrifices the cathode sulfur redox kinetics. To address the above dilemma, a redox comediation strategy for EPSE is proposed to realize high-energy-density and long-cycling Li–S batteries. Concretely, dimethyl diselenide (DMDSe) is employed as an efficient redox comediator to facilitate the sulfur redox kinetics in Li–S batteries with EPSE. DMDSe enhances the liquid–liquid and liquid–solid conversion kinetics of LiPS in EPSE while maintains the ability to alleviate the anode parasitic reactions from LiPSs. Consequently, a Li–S pouch cell with a high energy density of 359 Wh kg⁻¹ at cell level and stable 37 cycles is realized. This work provides an effective redox comediation strategy for EPSE to simultaneously achieve high energy density and long cycling stability in Li–S batteries and inspires rational integration of multi-strategies for practical working batteries.     

A Deeper Understanding of Metal Nucleation and Growth in Rechargeable Metal Batteries Through Theory and Experiment

Lithium and sodium metal batteries continue to occupy the forefront of battery research. Their exceptionally high energy density and nominal voltages are highly attractive for cutting-edge energy storage applications. Anode-free metal batteries are also coming into the research spotlight offering improved safety and even higher energy densities than conventional metal batteries. However, uneven metal nucleation and growth which leads to dendrites continues to limit the commercialisation of conventional and anode-free metal batteries alike. This review connects models and theories from well-established fields in metallurgy and electrodeposition to both conventional and anode-free metal batteries. These highly applicable models and theories explain the driving forces of uneven metal growth and can inform future experiment design. Finally, the models and theories that are most relevant to each anode-related cell component are identified. Keeping these specific models and theories in mind will assist with rational design for these components.     

New electrochemical energy storage systems based on metallic lithium anode—the research status,problems and challenges of lithium-sulfur,lithium-oxygen and all solid state batteries

Li-ion batteries have played a key role in the portable electronics and electrification of transport in modern society. Nevertheless,the limited highest energy density of Li-ion batteries is not sufficient for the long-term needs of society. Since lithium is the lightest metal among all metallic elements and possesses the lowest redox potential of.3.04 V vs. standard hydrogen electrode, it delivers the highest theoretical specific capacity of 3860 mA h g~(-1) and a high working voltage of full batteries which causes a great interest in electrochemical energy storage systems. Lithium-sulfur, lithium-oxygen and corresponding all solid state batteries based on metal lithium anode have received widely attention owing to their high energy densities. However, the problems in the cathode,electrolyte and anode of these three systems restrict their practical application. In this review, the research status and problems of these three energy storage systems are summarized and the challenges and future perspectives are also outlined.     

Reaction mechanism and additional lithium storage of mesoporous MnO_2 anode in Li batteries

Nanostructured transition metal oxides,employed as anode materials for lithium-ion batteries,exhibit a higher capacity than the theoretical capacity based on the conversion reaction.To date,the reasons behind this phenomenon are unclear.For the one-step evolution of anode material for lithium-ion batteries,it is essential to understand the lithium storage reaction mechanism of the anode material.Herein,we provide a detailed report on the lithium storage and release mechanism of MnO2,using synchrotron-based X-ray techniques.X-ray diffraction and X-ray absorption spectroscopy results indicate that during the first discharge,MnO2 is reduced in the order of MnO2→LixMnO2(1相似文献   

Polyimide Compounds For Post-Lithium Energy Storage Applications

The exploration of cathode and anode materials that enable reversible storage of mono and multivalent cations has driven extensive research on organic compounds. In this regard, polyimide (PI)-based electrodes have emerged as a promising avenue for the development of post-lithium energy storage systems. This review article provides a comprehensive summary of the syntheses, characterizations, and applications of PI compounds as electrode materials capable of hosting a wide range of cations. Furthermore, the review also delves into the advancements in PI based solid state batteries, PI-based separators, current collectors, and their effectiveness as polymeric binders. By highlighting the key findings in these areas, this review aims at contributing to the understanding and advancement of PI-based structures paving the way for the next generation of energy storage systems.     

多孔泡沫铜和硫脲协同作用构筑无枝晶锂负极

锂金属作为下一代储能电池的理想负极材料一直受到极大的关注,然而锂枝晶的不可控生长和负极副反应带来的低库伦效率问题严重限制了锂金属电池的发展。这里,我们提出了一种多孔泡沫铜和硫脲协同作用的策略,利用硫脲分子的超填充作用实现锂金属在多孔泡沫铜表面的均匀沉积。在电解液中添加0.02 mol·L^-1硫脲作为电解质添加剂,采用多孔泡沫铜的Li||Cu半电池在循环300圈以后,库伦效率仍保持在98%以上。此外,在5C的高倍率条件下,Li||Li FePO4全电池循环300圈以后仍有94%的容量保持率。本工作为锂金属负极保护提供了一种新的策略并且该策略也可以扩展到其他金属负极保护中,非常有利于下一代高能量密度储能电池的开发。     

Challenges of Lithium Metal Anode Enlightened from 2019 Nobel Prize in Chemistry

The 2019 Nobel Prize in Chemistry was awarded to three scientists who have made great contributions in discovery of lithium-ion batteries(LIBs). The LIBs with graphite as anode have dominated the rechargeable battery markets of portable electronics and electric vehicles(EVs). For the next-generation batteries, high energy density is the important trend of development. Thus lithium metal is considered as the most promising anode owing to its highest theoretical capacity and the lowest electrochemical potential. However, the severe safety concerns hinder its practical application. The uncontrollable growth of lithium dendrites leads to capacity decay, low Coulombic efficiency, possible short circuit and thermal runaway. In this perspective, various methods to protect Li metal anode have been analyzed. The development of solid-state electrolytes(SSEs) and the role of lithium anode in SSEs are discussed. Several new strategies for improving the safety of Li metal based batteries are proposed to realize the real market-oriented security applications.     

Active Diluent-Anion Synergy Strategy Regulating Nonflammable Electrolytes for High-Efficiency Li Metal Batteries

High-energy Li metal batteries (LMBs) consisting of Li metal anodes and high-voltage cathodes are promising candidates of the next generation energy-storage systems owing to their ultrahigh energy density. However, it is still challenging to develop high-voltage nonflammable electrolytes with superior anode and cathode compatibility for LMBs. Here, we propose an active diluent-anion synergy strategy to achieve outstanding compatibility with Li metal anodes and high-voltage cathodes by using 1,2-difluorobenzene (DFB) with high activity for yielding LiF as an active diluent to regulate nonflammable dimethylacetamide (DMAC)-based localized high concentration electrolyte (LHCE-DFB). DFB and bis(fluorosulfonyl)imide (FSI⁻) anion cooperate to construct robust LiF-rich solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI), which effectively stabilize DMAC from intrinsic reactions with Li metal anode and enhance the interfacial stability of the Li metal anodes and LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathodes. LHCE-DFB enables ultrahigh Coulombic efficiency (98.7 %), dendrite-free, extremely stable and long-term cycling of Li metal anodes in Li || Cu cells and Li || Li cells. The fabricated NCM811 || Li cells with LHCE-DFB display remarkably enhanced long-term cycling stability and excellent rate capability. This work provides a promising active diluent-anion synergy strategy for designing high-voltage electrolytes for high-energy batteries.     

Cobalt Oxide-Based Electrocatalysts with Bifunctionality for High-Performing Rechargeable Zinc-Air Batteries

In recent years, the rapid growth in renewable energy applications has created a significant demand for efficient energy storage solutions on a large scale. Among the various options, rechargeable zinc-air batteries (ZABs) have emerged as an appealing choice in green energy storage technology due to their higher energy density, sustainability, and cost-effectiveness. Regarding this fact, a spotlight is shaded on air electrode for constructing high-performance ZABs. Cobalt oxide-based electrocatalysts on the air electrode have gained significant attention due to their extraordinary features. Particularly, exploration and integration of bifunctional behavior for energy storage has remarkably promoted both ORR and OER to facilitate the overall performance of the battery. The plot of this review is forwarded towards in-depth analysis of the latest advancements in electrocatalysts that are based on cobalt oxide and possess bifunctional properties along with an introduction of the fundamental aspects of ZABs, Additionally, the topic entails an examination of the morphological variations and mechanistic details mentioning about the synthesis processes. Finally, a direction is provided for future research endeavors through addressing the challenges and prospects in the advancement of next-generation bifunctional electrocatalysts to empower high-performing ZABs with bifunctional cobalt oxide.     

Recent Advances of Freestanding Cathodes for Li-S Batteries

Lithium-sulfur batteries (LSBs) with high energy density and low cost have been recognized as one of the most promising next-generation energy storage systems. Although it has taken decades of development, the practical application of LSBs has been hindered by several inherent obstacles, particularly the severe shuttle effect and sluggish reaction kinetics in the sulfur cathode. Various strategies have been proposed to address these problems via rational design of electrode materials and configurations. Freestanding sulfur cathode could be a promising strategy to improve the sulfur mass loading at the cathode level and energy density of LSBs. This minireview will briefly summary the recent advances in freestanding cathodes for LSBs. The advantages and disadvantages of various freestanding cathodes are discussed and the prospects for the development of flexible cathodes are envisioned.     

锂金属负极的挑战与改善策略研究进展

锂金属由于其高比容量和低电极电势等优点被认为是下一代高比能量电池体系中最有潜力的负极材料。然而由于锂金属的高活性,锂负极在循环过程中会产生大量的枝晶,导致SEI(solid-electrolyte interphase)破裂,并且枝晶增加了电极与电解液的接触面积,使得副反应进一步增加。此外,脱落的枝晶形成死锂,从而降低电池的充放电库仑效率。并且不可控的锂枝晶持续生长会刺穿隔膜引发电池短路,伴随着电池热失控等安全问题。本综述基于锂负极存在的主要挑战,结合理解锂枝晶的成核生长模型等机理总结并深度分析近些年来在液态和固态电解质体系中改善锂金属负极的主要策略及其作用机理,为促进高比能量锂金属电池的应用提供借鉴参考作用。     

下一代能源存储技术及其关键电极材料

由于能源危机与环境问题,全球能源的消耗正逐渐从传统化石能源转向其它清洁高效能源。高效清洁能源的存储是电动汽车和智能电网的关键技术,对新能源、新材料和新能源汽车国家战略新兴产业的发展具有重要意义。锂离子电池是目前广泛应用的一种能源存储器件。电动汽车和智能电网对能量密度、功率密度、循环寿命和成本等方面的要求越来越高,传统的锂离子电池面临巨大挑战,发展下一代能源存储技术迫在眉睫。高能量密度的锂硫电池和锂空气电池,低成本、高安全性的室温钠离子电池受到了越来越多的关注。本文简要总结了近年来锂硫电池、锂空气电池和钠离子电池及其关键电极材料的研究进展,并对这些新型能源存储技术存在的问题和未来的前景做出了分析和展望。     

《能源电化学材料》专辑序言

以电化学能量储存和转化为特点的电池、电容器等储能技术,正在信息通讯、新能源汽车、微电网、分布式发电、大型电力储能、智能电网等领域得到广泛应用,将有力推动能源互联网的快速发展. 作为储能核心技术之一的锂电池、钠电池与超级电容器,更加受到重视. 这些电化学储能装置的性能依赖于所使用的电极材料与结构等. 发展高能量密度、高功率密度和长循环寿命的低成本储能体系成为能源电化学材料研究的核心. 本专辑围绕锂离子电池、钠离子电池、锂硫电池、超级电容器等,收录了在该领域具有丰富研究经验的团队所撰写的8篇相关综述和研究论文. 其中,围绕下一代锂离子电池负极硅材料,邀请了3篇综述和研究论文;鉴于丰富的钠资源,在钠离子电池研究方面也邀请了3篇综述论文;同时在高能量密度的锂硫电池和高功率密度的超级电容器方面各邀请1篇论文. 从这些论文中,可以部分看出锂离子电池、钠离子电池、锂硫电池、超级电容器等能源电化学材料的研究进展. 希望借助此专辑的出版,能使广大读者更好地了解上述几类电池、电容器的研究现状,研究趋势和存在问题及挑战,为更深入地开展该领域研究提供参考,以推动我国能源电化学材料研究的进一步发展. 在此,对专辑的所有作者、审稿人及编辑部工作人员的辛勤劳动,表示最衷心的感谢！     

Bulk-Phase Reconstruction Enables Robust Zinc Metal Anodes for Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries are inherently safe, but the severe dendrite growth and corrosion reaction on zinc anodes greatly hinder their practical applications. Most of the strategies for zinc anode modification refer to the research of lithium metal anodes on surface regulation without considering the intrinsic mechanisms of zinc anode. Herein, we first point out that surface modification cannot permanently protect zinc anodes due to the unavoidable surface damage during the stripping process by solid–liquid conversion. A bulk-phase reconstruction strategy is proposed to introduce abundant zincophilic sites both on the surface and inside the commercial zinc foils. The bulk-phase reconstructed zinc foil anodes exhibit uniform surfaces with high zincophilicity even after deep stripping, significantly improving the resistance to dendrite growth and side reactions. Our proposed strategy suggests a promising direction for the development of dendrite-free metal anodes for practical rechargeable batteries with high sustainability.     

Metal-air batteries: from oxygen reduction electrochemistry to cathode catalysts

Because of the remarkably high theoretical energy output, metal-air batteries represent one class of promising power sources for applications in next-generation electronics, electrified transportation and energy storage of smart grids. The most prominent feature of a metal-air battery is the combination of a metal anode with high energy density and an air electrode with open structure to draw cathode active materials (i.e., oxygen) from air. In this critical review, we present the fundamentals and recent advances related to the fields of metal-air batteries, with a focus on the electrochemistry and materials chemistry of air electrodes. The battery electrochemistry and catalytic mechanism of oxygen reduction reactions are discussed on the basis of aqueous and organic electrolytes. Four groups of extensively studied catalysts for the cathode oxygen reduction/evolution are selectively surveyed from materials chemistry to electrode properties and battery application: Pt and Pt-based alloys (e.g., PtAu nanoparticles), carbonaceous materials (e.g., graphene nanosheets), transition-metal oxides (e.g., Mn-based spinels and perovskites), and inorganic-organic composites (e.g., metal macrocycle derivatives). The design and optimization of air-electrode structure are also outlined. Furthermore, remarks on the challenges and perspectives of research directions are proposed for further development of metal-air batteries (219 references).