柔性储能电池电极的设计、制备与应用EI北大核心CSCD

随着便携式、可穿戴电子器件的迅速发展,柔性储能器件的研究逐渐转向微型化、轻柔化和智能化等方向。同时人们对器件的能量密度、功率密度和力学性能有了更高的要求。电极材料作为柔性储能器件的核心部分,是决定器件性能的关键。柔性储能电子器件的发展,又迫切需要新型电池技术和快速、低成本且可精准控制其微结构的制备方法。因此,柔性锂/钠离子电池、柔性锂硫电池、柔性锌空电池等新型储能器件的研发成为目前学术界研究的热点。本文论述了近年来柔性储能电池电极的研究现状,着重对柔性电极材料的设计(独立柔性电极和柔性基底电极)、不同维度柔性电极材料的制备工艺(一维材料、二维材料和三维材料)和柔性储能电极的应用(柔性锂/钠离子电池、柔性锂硫电池、柔性锌空电池)进行对比分析,并对电极材料的结构特性和电化学性能进行了讨论。最后,指出了柔性储能器件目前所面临的问题,并针对此类问题展望了柔性储能器件未来的重点在于新型固态电解质的研发、器件结构的合理设计及封装技术的不断优化。     

Lithium garnets: Synthesis,structure, Li+ conductivity,Li+ dynamics and applications

Inorganic solid fast Li⁺ conductors based batteries are expected to overcome the limitations over safety concerns of flammable organic polymer electrolytes based Li⁺ batteries. Hence, an all-solid-state Li⁺ battery using non-flammable solid electrolyte have attracted much attention as next-generation battery. Therefore, in the development of all-solid-state lithium rechargeable batteries, it is important to search for a solid electrolyte material that has high Li⁺ conductivity, low electronic conductivity, fast charge transfer at the electrode interface and wide electrochemical window stability against potential electrodes and lithium metal. Hence, significant research effort must be directed towards developing novel fast Li⁺ conductors as electrolytes in all-solid-state lithium batteries. Among the reported inorganic solid Li⁺ conductive oxides, garnet-like structural compounds received considerable attention in recent times for potential application as electrolytes in all-solid-state lithium batteries. The focus of this review is to provide comprehensive overview towards the importance of solid fast lithium ion conductors, advantages of lithium garnets over other ceramic lithium ion conductors and understanding different strategies on synthesis of lithium garnets. Attempts have also been made to understand relationship between the structure, Li⁺ conduction and Li⁺ dynamics of lithium garnets. The status of lithium garnets as solid electrolyte in electrochemical devices like all-solid state lithium battery, lithium-air battery and sensor are also discussed.     

有机电解液在钠离子电池中的研究进展

随着对大型储能电池的需求逐渐增加,钠离子电池由于其资源丰富,价格低廉且与锂性质相似等优点而被广泛关注。在钠离子电池的关键材料选择中,钠离子电池的电化学性能和安全性同时受电解液的影响,这不仅决定了电池的电化学窗口和能量密度,而且还控制着电极/电解液界面的性质。本文首先综述了钠离子电池电解质的基本要求、主要分类,重点讨论了对钠离子电池电解质的选择性要求及不同钠盐的物化性能和对固体电解质界面的影响;其次针对不同溶剂和材料的兼容性以及材料在不同溶剂体系中的储能机制等,分别对材料在醚类和酯类电解液中获得的固体电解质界面特点、倍率性能、循环性能等展开分析。最后指出钠离子电池电解质未来在与材料的匹配、关键性表征方法等方面的发展路线。     

量子点/碳复合材料在碱金属离子电池的应用进展EI北大核心

碱金属离子电池作为可充电电池,是目前重要的储能设备之一。它凭借能量密度大、工作电压高、无“记忆效应”、自放电小、绿色无污染等优点在近些年来受到人们的广泛关注。电极材料是影响碱金属离子电池电化学性能的重要因素之一,因此,寻求比容量高、结构稳定的电极材料是推动碱金属离子电池发展的关键。量子点/碳复合材料(QDs/C)集合量子点与碳材料的优势,是碱金属离子电池优异的候选电极材料。本文首先对量子点进行简要介绍,然后分别综述单质量子点/碳复合材料、化合物量子点/碳复合材料及异质结构量子点/碳复合材料在碱金属离子电池中的应用进展。最后,分析量子点/碳复合材料作为碱金属离子电池电极材料的优势与不足,针对目前存在的问题提出了未来发展的方向:(1)探索新型方法,解决量子点及其复合材料的团聚问题;(2)研究SEI膜的结构性能等,解决首次库仑效率偏低的问题;(3)明确反应机理,获取更优异的电化学性能。     

Defect Engineering on Electrode Materials for Rechargeable Batteries

The reasonable design of electrode materials for rechargeable batteries plays an important role in promoting the development of renewable energy technology. With the in-depth understanding of the mechanisms underlying electrode reactions and the rapid development of advanced technology, the performance of batteries has significantly been optimized through the introduction of defect engineering on electrode materials. A large number of coordination unsaturated sites can be exposed by defect construction in electrode materials, which play a crucial role in electrochemical reactions. Herein, recent advances regarding defect engineering in electrode materials for rechargeable batteries are systematically summarized, with a special focus on the application of metal-ion batteries, lithium–sulfur batteries, and metal–air batteries. The defects can not only effectively promote ion diffusion and charge transfer but also provide more storage/adsorption/active sites for guest ions and intermediate species, thus improving the performance of batteries. Moreover, the existing challenges and future development prospects are forecast, and the electrode materials are further optimized through defect engineering to promote the development of the battery industry.     

3Ah高镍/硅氧碳软包电池循环容量衰减分析EI北大核心CSCD

随着电动汽车的发展,对电池能量密度提出了更高的要求,具有高能量密度的高镍/硅氧碳软包电池成为长续航电动汽车的首选,但是高镍/硅氧碳电池在实际使用中存在容量快速衰减的问题。采用无损电化学分析和事后拆解分析对循环过程中电池容量和内阻的变化进行检测,通过对比电池循环前后正负极结构、材料形貌和表面成分的变化,揭示高镍/硅氧碳电池循环失效机制。结果表明:电池容量衰减呈现平稳期、快速衰减期和急速衰减期3个阶段。循环后电池极化更加严重,电池极化内阻、负极表面膜阻抗和电荷转移阻抗明显增加。通过微分曲线分析结合拆解分析发现,高镍正极材料衰减较少,硅氧碳负极材料衰减和活性锂离子损失较多。硅氧颗粒膨胀开裂,负极活性物质损失,负极表面膜连续生长消耗过多的活性锂为电池容量快速衰减的主要原因。     

An Overview of Fiber-Shaped Batteries with a Focus on Multifunctionality,Scalability, and Technical Difficulties

Flexible and wearable energy storage devices are receiving increasing attention with the ever-growing market of wearable electronics. Fiber-shaped batteries display a unique 1D architecture with the merits of superior flexibility, miniaturization potential, adaptability to deformation, and compatibility with the traditional textile industry, which are especially advantageous for wearable applications. In the recent research frontier in the field of fiber-shaped batteries, in addition to higher performance, advances in multifunctional, scalable, and integrable systems are also the main themes. However, many difficulties exist, including difficult encapsulation and installation of separators, high internal resistance, and poor durability. Herein, the design principles (e.g., electrode preparation and battery assembly) and device performance (e.g., electrochemical and mechanical properties) of fiber-shaped batteries, including lithium-based batteries, zinc-based batteries, and some other representative systems, are summarized, with a focus on multifunctional devices with environmental adaptability, stimuli-responsive properties, and scalability up to energy textiles, with the hope of enlightening future research directions. Finally, technical challenges in the realistic wearable application of these batteries are also discussed with the aim of providing possible solutions and new insights for further improvement.     

Evolution of 3D Printing Methods and Materials for Electrochemical Energy Storage

Additive manufacturing has revolutionized the building of materials, and 3D-printing has become a useful tool for complex electrode assembly for batteries and supercapacitors. The field initially grew from extrusion-based methods and quickly evolved to photopolymerization printing, while supercapacitor technologies less sensitive to solvents more often involved material jetting processes. The need to develop higher-resolution multimaterial printers is borne out in the performance data of recent 3D printed electrochemical energy storage devices. Underpinning every part of a 3D-printable battery are the printing method and the feed material. These influence material purity, printing fidelity, accuracy, complexity, and the ability to form conductive, ceramic, or solvent-stable materials. The future of 3D-printable batteries and electrochemical energy storage devices is reliant on materials and printing methods that are co-operatively informed by device design. Herein, the material and method requirements in 3D-printable batteries and supercapacitors are addressed and requirements for the future of the field are outlined by linking existing performance limitations to requirements for printable energy-storage materials, casings, and direct printing of electrodes and electrolytes. A guide to materials and printing method choice best suited for alternative-form-factor energy-storage devices to be designed and integrated into the devices they power is thus provided.     

Molten salts for rechargeable batteries

The growing demand of advanced electrochemical energy storage devices for various applications, including portable electronic products, electric vehicles, and large-scale energy storage grids, has triggered extensive research interests and efforts on various rechargeable batteries such as lithium/sodium-ion batteries (LIBs/NIBs), aluminium-ion batteries (AIBs), liquid metal batteries (LMBs), and molten-air batteries (MABs) in the past decades. A key issue to push forward the development of these batteries is the exploration of high-performance electrodes and electrolytes, which calls for efficient and versatile synthetic methods. Molten salts (MSs), liquid-phase ionic compounds or mixtures, provide an effective platform to widen the reaction temperatures and enrich the chemical environments for the synthesis of novel electrode materials and electrolytes. In this review, the general principles of molten salts and recent research progresses on molten salt-based battery materials are surveyed. Molten-salt synthesis of electrode materials, including sintering and electrolysis, are emerging as competitive substitutes for conventional synthesis techniques. These methods have shown their effectiveness and uniqueness in adjusting the crystal structure, morphology, and performance of electrode materials for LIBs/NIBs, as suggested by recent progresses and applications of diverse cathodes (layered oxides, spinel oxides, polyanions, etc.) and anodes (metal oxides, alloys, carbons, etc.). Furthermore, the applications of molten salts as effective electrolytes are demonstrated in representative new-type secondary batteries including AIBs, LMBs and MABs. Finally, the emerging opportunities, challenges, and interesting research trends are envisioned to promote the further development of molten-salt methodology for rechargeable batteries.     

Compact energy storage enabled by graphenes: Challenges,strategies and progress

Storing as much energy as possible in as compact a space as possible is an ever-increasing concern to deal with the emerging “space anxiety” in electrochemical energy storage (EES) devices like batteries, which is known as “compact energy storage”. Carbons built from graphene units can be used as active electrodes or inactive key materials acting as porous micro- or even nano-reactors that facilitate battery reactions and play a vital role in optimizing the volumetric performance of the electrode and the battery. In this review, we discuss and clarify the key issues and specific strategies for compact energy storage, especially in batteries. The use of shrinkable carbon networks to produce small yet sufficient reaction space together with smooth charge delivery is highlighted as the simplest structure–function-performance relationship when used in supercapacitors and is then extended to overcome problems in compact rechargeable lithium/sodium/potassium batteries. Special concerns about cycling stability, fast charging and safety in compact batteries are discussed in detail. Strategies for compact energy storage ranging from materials to electrodes to batteries are reviewed here to provide guidance for how to produce a compact high energy battery by densifying the electrodes using customized carbon structures.     

Plasma‐Assisted Synthesis and Surface Modification of Electrode Materials for Renewable Energy

Renewable energy technology has been considered as a “MUST” option to lower the use of fossil fuels for industry and daily life. Designing critical and sophisticated materials is of great importance in order to realize high‐performance energy technology. Typically, efficient synthesis and soft surface modification of nanomaterials are important for energy technology. Therefore, there are increasing demands on the rational design of efficient electrocatalysts or electrode materials, which are the key for scalable and practical electrochemical energy devices. Nevertheless, the development of versatile and cheap strategies is one of the main challenges to achieve the aforementioned goals. Accordingly, plasma technology has recently appeared as an extremely promising alternative for the synthesis and surface modification of nanomaterials for electrochemical devices. Here, the recent progress on the development of nonthermal plasma technology is highlighted for the synthesis and surface modification of advanced electrode materials for renewable energy technology including electrocatalysts for fuel cells, water splitting, metal–air batteries, and electrode materials for batteries and supercapacitors, etc.     

MOFs及衍生复合材料在锂硫电池中的设计应用

在能源危机与环境问题日益凸显的背景下,电化学储能技术得到了迅速发展。在“超越锂”储能领域的竞争者中,锂硫电池(Li-S)因其具有高理论比容量、高质量能量密度并且环境友好、价格低廉等优点,成为最有前途的新储能技术。但是,锂硫电池的发展仍存在一些瓶颈问题需要解决,例如正极材料导电性能差、多硫化物穿梭效应及在充放电过程中电极体积膨胀等。作为锂硫电池的关键组成部分,电极和隔膜材料的设计和制备对解决这些问题及电池整体性能提升起到了重要的作用。金属有机骨架(MOFs)及衍生的复合材料作为锂硫电池电极或隔膜修饰材料,具有质量轻、电子和离子传导性好、孔道丰富和活性位点均匀分布等优势。此外,这类复合材料还具备形貌和组分可控、来源丰富和孔径可调等特性,从而便于机制研究。本文全面介绍了锂硫电池组成、工作原理并综述了近几年MOFs及衍生复合材料在锂硫电池中的研究进展,重点讨论了其在正极材料和隔膜材料中的应用,并对未来该材料在锂硫电池研究方向上的前景和突破进行了展望。      

The Regulating Role of Carbon Nanotubes and Graphene in Lithium‐Ion and Lithium–Sulfur Batteries

The ever‐increasing demands for batteries with high energy densities to power the portable electronics with increased power consumption and to advance vehicle electrification and grid energy storage have propelled lithium battery technology to a position of tremendous importance. Carbon nanotubes (CNTs) and graphene, known with many appealing properties, are investigated intensely for improving the performance of lithium‐ion (Li‐ion) and lithium–sulfur (Li–S) batteries. However, a general and objective understanding of their actual role in Li‐ion and Li–S batteries is lacking. It is recognized that CNTs and graphene are not appropriate active lithium storage materials, but are more like a regulator: they do not electrochemically react with lithium ions and electrons, but serve to regulate the lithium storage behavior of a specific electroactive material and increase the range of applications of a lithium battery. First, metrics for the evaluation of lithium batteries are discussed, based on which the regulating role of CNTs and graphene in Li‐ion and Li–S batteries is comprehensively considered from fundamental electrochemical reactions to electrode structure and integral cell design. Finally, perspectives on how CNTs and graphene can further contribute to the development of lithium batteries are presented.     

高镍三元锂离子电池低温放电性能研究进展EI北大核心CSCD

随着新能源汽车产业的迅速发展,消费者对电动汽车续航里程的要求不断提高。高镍三元锂离子电池因其比能量高成为电动汽车中最具应用前景的动力电池,但该电池体系依然面临着低温性能差的问题。本文综述近年来高镍三元锂离子电池低温性能的研究进展,重点总结高镍三元锂离子电池低温性能的影响因素,一方面从热力学角度分析低温下高镍三元正极材料和石墨负极材料的结构变化、电解液相态和溶剂化结构变化以及黏结剂玻璃化转变对电池低温性能的影响;另一方面从动力学角度分析高镍三元电池低温放电过程中的速率控制步骤。归纳目前高镍三元锂离子电池低温性能的主要改善措施,其中低温电解液的设计包括优化溶剂、改善锂盐及使用新型添加剂三个方面,对电极材料低温性能的改善主要是通过体相掺杂、表面包覆及材料颗粒粒径降低的方式。总结电池中低温性能研究中存在的对电池低温热力学特性研究不够明确、对电池低温动力学过程研究方式单一以及对电池中的反应顺序存在的影响认识不足等问题。     

3D-Printed Silicone Substrates as Highly Deformable Electrodes for Stretchable Li-Ion Batteries

Stretchable energy storage devices receive a considerable attention at present due to their growing demand for powering wearable electronics. A vital component in stretchable energy storage devices is its electrode which should endure a large and repeated number of mechanical deformations during its prolonged use. It is crucial to develop a technology to fabricate highly deformable electrode in an easy and an economic manner. Here, the fabrication of stretchable electrode substrates using 3D-printing technology is reported. The ink for fabricating it contains a mixture of sacrificial sugar particles and polydimethylsiloxane resin which solidifies upon thermal curing. The printed stretchable substrate attains a porous structure after leaching the sugar particles in water. The resulting printed porous stretchable substrates are then utilized as electrodes for Li-ion batteries (LIBs) after loading them with electrode materials. The batteries with stretchable electrodes exhibit a decent electrochemical performance comparable to that of the conventional electrodes. The stretchable electrodes also exhibit a stable electrochemical performance under various mechanical deformations and even after several hundreds of stretch/release cycles. This work provides a feasible route for constructing LIBs with high stretchability and enhanced electrochemical performance thereby providing a platform for realizing stretchable batteries for next generation wearable electronics.     

锂离子电池正极负极材料研究进展

近年来,锂离子电池因其优异的特性,发展十分迅速。锂离子电池的优异性能与电池的材料选择,材料的制备工艺等密切相关,可以说,锂离子电池的性能,很大程度上取决于电池的正负极材料以及电解质和隔膜材料的选择和制备。基于这种的重要性,本文对目送２锂离子电池的正极和负极材料的研究进展进行了综合评述。     

Metal organic framework (MOF) in aqueous energy devices

Aqueous energy devices are under the spotlight of current research due to their safety, low cost and ease of handling. Metal-organic frameworks (MOFs) and their derivatives have spurred extensive exploration as they provide a library of new electrode materials. The rich and structural flexibilities (such as metal nodes, ligands, pore structure) endow MOFs and MOFs-derivatives with vast opportunities for various energy devices. In this review, we discuss the correlation between MOF structural parameters and electrochemical performance for aqueous energy devices in the scope of zinc-based batteries (Zn-ion, Zn-alkaline and Zn-air batteries), potassium-ion batteries and supercapacitors. For each energy device, the effect of determinative factors and structural modulating strategies of MOFs and derivatives are highlighted. Finally, we summarize the challenges and provide our perspective about MOFs and derivatives for future aqueous energy devices.     

Review of Design Routines of MXene Materials for Magnesium-Ion Energy Storage Device

Renewable energy storage using electrochemical storage devices is extensively used in various field applications. High-power density supercapacitors and high-energy density rechargeable batteries are some of the most effective devices, while lithium-ion batteries (LIBs) are the most common. Due to the scarcity of Li resources and serious safety concerns during the construction of LIBs, development of safer and cheaper technologies with high performance is warranted. Magnesium is one of the most abundant and replaceable elements on earth, and it is safe as it does not generate dendrite following cycling. However, the lack of suitable electrode materials remains a critical issue in developing electrochemical energy storage devices. 2D MXenes can be used to construct composites with different dimensions, owing to their suitable physicochemical properties and unique magnesium-ion adsorption structure. In this study, the construction strategies of MXene in different dimensions, including its physicochemical properties as an electrode material in magnesium ion energy storage devices are reviewed. Research advancements of MXene and MXene-based composites in various kinds of magnesium-ion storage devices are also analyzed to understand its energy storage mechanisms. Finally, current opportunities, challenges, and future prospects are also briefly discussed to provide crucial information for future research.     

High‐Performance Integrated Self‐Package Flexible Li–O2 Battery Based on Stable Composite Anode and Flexible Gas Diffusion Layer

With the rising development of flexible and wearable electronics, corresponding flexible energy storage devices with high energy density are required to provide a sustainable energy supply. Theoretically, rechargeable flexible Li–O₂ batteries can provide high specific energy density; however, there are only a few reports on the construction of flexible Li–O₂ batteries. Conventional flexible Li–O₂ batteries possess a loose battery structure, which prevents flexibility and stability. The low mechanical strength of the gas diffusion layer and anode also lead to a flexible Li–O₂ battery with poor mechanical properties. All these attributes limit their practical applications. Herein, the authors develop an integrated flexible Li–O₂ battery based on a high‐fatigue‐resistance anode and a novel flexible stretchable gas diffusion layer. Owing to the synergistic effect of the stable electrocatalytic activity and hierarchical 3D interconnected network structure of the free‐standing cathode, the obtained flexible Li–O₂ batteries exhibit superior electrochemical performance, including a high specific capacity, an excellent rate capability, and exceptional cycle stability. Furthermore, benefitting from the above advantages, the as‐fabricated flexible batteries can realize excellent mechanical and electrochemical stability. Even after a thousand cycles of the bending process, the flexible Li–O₂ battery can still possess a stable open‐circuit voltage, a high specific capacity, and a durable cycle performance.     

基于离子选择性迁移策略的动力/储能电池隔膜的研究进展

随着锂离子电池等新能源电池在动力/储能领域的不断发展,传统商业聚烯烃隔膜由于润湿性与离子选择性差、孔隙率低等缺点已不能满足高性能锂电池的发展需要。近年来学者针对提升隔膜离子导电性能方面做了大量研究,然而锂电池充放电过程中通常只有阳离子传输参与氧化还原反应,二元电解质中锂离子通常被溶剂分子包围形成较大的溶剂鞘导致阴离子的移动能力反而强于锂离子,电池内部低的阳离子传输效率导致电池出现浓差极化、锂枝晶等问题,限制电池在高倍率下的应用,因此设计抑制阴离子穿梭促进阳离子快速迁移的新型电池隔膜在提升电池综合性能方面具有优异的发展前景。本文从近期的研究热点出发,主要从基团功能化设计、路易斯酸的俘获效应、空间筛分等策略详细介绍基于提升阳离子迁移能力的新型隔膜在电池领域的发展,最后总结指出电池隔膜领域存在的挑战和未来的发展方向。