全固态锂硫电池中界面问题的研究现状

由于锂金属负极的理论比容量和固态电解质的安全性高,全固态锂硫电池越来越受到研究者的青睐.与液态锂硫电池相比,全固态锂硫电池最大的不同在于使用固态电解质替换了液态电解质,且固态电解质材料不可燃,因此有着更高的安全性.此外,经过优化处理后的固态电解质有着足够的机械强度,可以有效抑制锂枝晶的产生.同时在产品的制备和运输方面,全固态电池也有着更大的优势.然而,全固态电池中存在着大量的固固界面,这些固固界面会导致在循环过程中产生界面电阻、体积畸变等一系列问题,会制约全固态锂硫电池的商业应用.因此,近年来学者们对固固界面进行了广泛的研究,不断改进制备工艺,表征界面变化过程,并对离子迁移路径进行了模拟和验证.目前,全固态锂硫电池已经有部分投入了商业应用.全固态锂硫电池主要包括含硫正极、锂金属负极和固态电解质,而固态电解质主要分为无机固态电解质和有机固态电解质两大类.因此,对固态电解质界面的研究也可以分为两大类:一类是固态电解质内部界面,包括无机电解质与无机电解质之间的界面或者无机电解质与有机电解质之间的界面,该界面主要对离子电导率有着重要影响;另一类主要包括固态电解质与正负极之间的界面,对电池的化学稳定性、体积稳定性和离子电导率等均存在较大的影响.近年来,研究者发现通过改变混合方法、粒径、多孔基体和体积压力等能够有效改善界面.同时,随着表征技术的发展,越来越多的原位界面表征技术能够更加直观地展现界面的变化状态.本文系统性地阐述了全固态锂硫电池的内、外界面存在的问题和研究现状,并探讨了全固态锂硫电池未来的发展趋势和研究重点,以期为制备稳定、高性能的全固态锂硫电池提供参考.     

锂金属电池中复合固态电解质与负极界面的研究进展

与传统锂离子电池相比,全固态锂金属电池因其安全性好、能量密度高的特点备受关注.但是电极与固态电解质的固固接触带来较大的界面阻抗,而锂金属较为活泼易与固态电解质发生反应,造成了界面不稳定.界面问题已经成为制约全固态电池发展的关键因素之一.有机-无机复合固态电解质兼顾无机固态电解质和有机固态电解质的优势,具有较高离子电导率和一定的力学强度,展现出优异的实用化前景.本文综述了近年来复合固态电解质与金属锂负极界面改性的研究进展,总结了当前界面改性的主要研究思路:包括在界面构筑"软接触"、调节固态电解质的力学性能以及调控界面处锂离子的沉积动力学过程等.同时,也对今后界面改性的研究趋势进行了展望.     

全固态锂电池中金属锂负极及其界面设计的研究进展

锂金属具有低的氧化还原电位(-3.04 V vs标准氢电极)和高比容量(3860 mAh/g),是理想的锂二次电池负极材料.由金属锂负极/固态电解质/嵌锂正极组装的固态锂电池,有望成为未来航空航天、机器人、高端电子和电动汽车等相关技术产业的动力源.然而,在充放电过程中,由于锂的不均匀沉积-溶解造成锂与电解质接触面产生大量树枝状枝晶,并沿着电解质方向不断生长,最终造成电池内部短路而失效.使用较高杨氏模量的固态电解质,可以很大程度上阻挡锂枝晶的生长,但仍不能满足电池长循环和安全性的要求.此外,金属锂与固态电解质表面是固固接触,造成了界面电阻大以及金属锂与固态电解质的界面反应等问题,这严重阻碍了固态锂金属电池的发展与使用.本文综述了近年来基于固态电解质的金属锂电池抑制锂枝晶生长和提高固固界面相容性的相关策略,并对金属锂/固态电解质界面设计的发展趋势进行展望.     

Li7La3Zr2O12固态电解质负极界面研究进展

石榴石型固态电解质锂镧锆氧(Li₇La₃Zr₂O₁₂,LLZO)具有高达5 V的宽电化学窗口,在固态电解质体系中,与金属锂负极具有良好的匹配性,使其有望成为下一代高能量电池。但LLZO与电极界面的稳定性问题极大地限制了其实际应用。本文从金属锂负极特性、LLZO电解质特性、LLZO/Li界面接触三个方面对LLZO/Li界面的稳定性问题展开分析,阐述界面稳定性的根源,同时对界面优化方法进行总结,提出LLZO/Li负极界面发展应注意的问题。     

人造固态电解质界面在锂金属负极保护中的应用研究EI北大核心CSCD

锂金属具有最低的氧化还原电位(-3.04V vs标准氢电极)和极高的比容量(3860mAh·g^-1),是理想的锂二次电池负极材料.然而电化学循环过程中,由于锂的不均匀成核生长,其表面产生锂枝晶,锂枝晶持续生长会刺穿隔膜,造成电池短路甚至引发火灾.因此需要对锂金属负极进行保护,抑制负面问题,发挥高性能.人造固态电解质界面技术是一种有效的锂金属负极保护策略,本质是预先在锂金属表面涂覆上保护层,保护层具有较高的离子传导性和电化学稳定性、较好的阻隔性和机械强度,可得到高效率、长寿命和无枝晶的锂金属负极.本文将近年来人造固态电解质界面在锂金属负极保护中的研究进展进行综述,对其制备方法、结构特点、锂金属负极循环性能、全电池电化学性能等方面作了详细介绍,分析当前存在问题并指出锂金属负极研究不仅需要加深机理研究还得与实际应用相结合.     

合金材料在锂金属负极中的应用研究进展EI北大核心

金属锂具有极低的电极电势及超高的比容量,是高比能锂二次电池的理想负极材料。然而,锂枝晶生长、体积膨胀效应及界面不稳定等问题限制了其商业化应用。通过合金负极、界面保护、负极结构设计及固态电解质等策略,可显著改善上述问题。锂合金材料具有高比容量、高离子电导率及良好亲锂性等特点,在上述策略中均扮演着重要角色。本文介绍合金材料的电化学性质,综述近年来合金材料在锂金属负极中的应用研究进展;最后梳理合金材料在锂金属负极中应用所面临的问题,并提出加强基础理论研究等建议。     

合金材料在锂金属负极中的应用研究进展

金属锂具有极低的电极电势及超高的比容量，是高比能锂二次电池的理想负极材料。然而，锂枝晶生长、体积膨胀效应及界面不稳定等问题限制了其商业化应用。通过合金负极、界面保护、负极结构设计及固态电解质等策略，可显著改善上述问题。锂合金材料具有高比容量、高离子电导率及良好亲锂性等特点，在上述策略中均扮演着重要角色。本文介绍合金材料的电化学性质，综述近年来合金材料在锂金属负极中的应用研究进展；最后梳理合金材料在锂金属负极中应用所面临的问题，并提出加强基础理论研究等建议。     

石墨烯在固态电池界面改性中的应用

全固态锂电池具有安全可靠性高、能量密度大、循环寿命长、电化学窗口宽、高温适应性强等优点，制约其实际应用的主要瓶颈在于电极与固态电解质之间的界面问题，包括负极界面区的锂枝晶、体积膨胀，正极界面区的结构变化、空间电荷层、界面反应等。石墨烯因其特殊的二维结构，优良的导电、导热及力学性能而广泛应用于电化学储能领域。综述了石墨烯在电极/固态电解质界面改性方面的研究进展，并对石墨烯在固态电池领域的应用前景进行了展望。     

人造固态电解质界面在锂金属负极保护中的应用研究

锂金属具有最低的氧化还原电位(-3.04 V vs标准氢电极)和极高的比容量(3860 mAh·g~(-1)),是理想的锂二次电池负极材料。然而电化学循环过程中,由于锂的不均匀成核生长,其表面产生锂枝晶,锂枝晶持续生长会刺穿隔膜,造成电池短路甚至引发火灾。因此需要对锂金属负极进行保护,抑制负面问题,发挥高性能。人造固态电解质界面技术是一种有效的锂金属负极保护策略,本质是预先在锂金属表面涂覆上保护层,保护层具有较高的离子传导性和电化学稳定性、较好的阻隔性和机械强度,可得到高效率、长寿命和无枝晶的锂金属负极。本文将近年来人造固态电解质界面在锂金属负极保护中的研究进展进行综述,对其制备方法、结构特点、锂金属负极循环性能、全电池电化学性能等方面作了详细介绍,分析当前存在问题并指出锂金属负极研究不仅需要加深机理研究还得与实际应用相结合。     

应用于全固态锂电池的复合固态电解质研究进展

基于固态电解质和锂金属负极的全固态锂离子电池能量密度高、 安全性好,能够有效地抑制锂枝晶生长并改善电池的本征安全性.固态电解质作为全固态电池的关键材料,成为近年来的研究热点.目前,通过在聚合物基体中添加无机填料得到的复合固态电解质具有优异的力学性能和电化学性能,实现了对单一固态电解质体系的"取长补短",被视为最具前景的...     

全固态锂离子电池中金属锂负极界面优化改性研究

以共聚物PEDOT-co-PEG作为锂金属阳极的表面改性层,采用磷酸铁锂复合阳极和“石榴石型”物质以及聚合氧乙烷聚合物组成的固体电解质制备了全固态锂离子电池。采用SEM分析了锂金属充电-放电反复操作后的形态学改变;采用电化学组抗谱试验研究了改性后的锂金属以及复合固体电解质接触面的稳定性并对全固态锂离子电池的充电-放电性能和界面稳定性进行了研究。结果表明,未改性的锂金属在固态电池充电-放电过程中会生成锂枝晶,从而导致全固态锂离子电池的高电流密度容量快速衰变;“石榴石型”物质以及聚合氧乙烷聚合物组成的固体电解质与改性后的金属锂具有良好的接触面,从而扼制锂枝晶的形成,提高全固态锂离子电池的机械性能;在PEDOT-co-PEG共聚物改性锂金属后,全固态锂离子电池的平稳性显著提高,且容量减弱放缓。     

All‐Solid‐State Batteries with a Limited Lithium Metal Anode at Room Temperature using a Garnet‐Based Electrolyte

Metallic lithium (Li), considered as the ultimate anode, is expected to promise high‐energy rechargeable batteries. However, owing to the continuous Li consumption during the repeated Li plating/stripping cycling, excess amount of the Li metal anode is commonly utilized in lithium‐metal batteries (LMBs), leading to reduced energy density and increased cost. Here, an all‐solid‐state lithium‐metal battery (ASSLMB) based on a garnet‐oxide solid electrolyte with an ultralow negative/positive electrode capacity ratio (N/P ratio) is reported. Compared with the counterpart using a liquid electrolyte at the same low N/P ratios, ASSLMBs show longer cycling life, which is attributed to the higher Coulombic efficiency maintained during cycling. The effect of the species of the interface layer on the cycling performance of ASSLMBs with low N/P ratio is also studied. Importantly, it is demonstrated that the ASSLMB using a limited Li metal anode paired with a LiFePO₄ cathode (5.9 N/P ratio) delivers a stable long‐term cycling performance at room temperature. Furthermore, it is revealed that enhanced specific energies for ASSLMBs with low N/P ratios can be further achieved by the use of a high‐voltage or high mass‐loading cathode. This study sheds light on the practical high‐energy all‐solid‐state batteries under the constrained condition of a limited Li metal anode.     

Polymer electrolytes and interfaces in solid-state lithium metal batteries

The polymer electrolyte based solid-state lithium metal batteries are the promising candidate for the high-energy electrochemical energy storage with high safety and stability. Moreover, the intrinsic properties of polymer electrolytes and interface contact between electrolyte and electrodes have played critical roles for determining the comprehensive performances of solid-state lithium metal batteries. In this review, the development of polymer electrolytes with the design strategies by functional units adjustments are firstly discussed. Then the interfaces between polymer electrolyte and cathode/anode, including the interface issues, remedy strategies for stabilizing the interface contact and reducing resistances, and the in-situ polymerization method for enhancing the compatibilities and assembling the batteries with favorable performances, have been introduced. Lastly, the perspectives on developing polymer electrolytes by functional units adjustment, and improving interface contact and stability by effective strategies for solid-state lithium metal batteries have been provided.     

Horizontal Growth of Lithium on Parallelly Aligned MXene Layers towards Dendrite‐Free Metallic Lithium Anodes

Although metallic lithium is an extremely promising anode for lithium‐based batteries due to its high theoretical capacity, the uncontrollable growth of lithium dendrites, in particular under deep stripping and plating, have stagnated its application. It is demonstrated that parallelly aligned MXene (Ti₃C₂T_x ) layers enable the efficient guiding of lithium nucleation and growth on the surface of 2D MXene nanosheets, giving rise to horizontal‐growth lithium anodes. Moreover, the inherent fluorine terminations in MXene afford a uniform and durable solid electrolyte interface with lithium fluoride at the anode/electrolyte interface, efficiently regulating electromigration of lithium ions. Thus, a dendrite‐free lithium anode with a long cycle life up to 900 h and excellent deep stripping–plating capabilities up to 35 mAh cm^?2 is achieved, which can further serve as an anode for a lithium metal battery, exhibiting high cycle stability up to 1000 cycles.     

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.     

塑料锂离子电池用聚合物电解质性能表征

以导电聚合物作为电解质的塑料锂离子电池被认为是迄今锂电池发展最新水平，研制性能优良的聚合物电解质是生产该种锂离子电池的关键技术，因此对聚合物电解质的表征是必不可少的步骤，电导率，扩散系数，迁移数和电化学窗口是表征聚合物电解质的重要指标，文中介绍了塑料锂离子电池用聚合物电解质性能的表征方法，给出了交流阻抗，浓差极化，断电流，线性伏安扫描等实验方法，并对其作为分析和讨论。     

Double‐Layer Polymer Electrolyte for High‐Voltage All‐Solid‐State Rechargeable Batteries

No single polymer or liquid electrolyte has a large enough energy gap between the empty and occupied electronic states for both dendrite‐free plating of a lithium‐metal anode and a Li⁺ extraction from an oxide host cathode without electrolyte oxidation in a high‐voltage cell during the charge process. Therefore, a double‐layer polymer electrolyte is investigated, in which one polymer provides dendrite‐free plating of a Li‐metal anode and the other allows a Li⁺ extraction from an oxide host cathode without oxidation of the electrolyte in a 4 V cell over a stable charge/discharge cycling at 65 °C; a poly(ethylene oxide) polymer contacts the lithium‐metal anode and a poly(N‐methyl‐malonic amide) contacts the cathode. All interfaces of the flexible, plastic electrolyte remain stable with no visible reduction of the Li⁺ conductivity on crossing the polymer/polymer interface.     

Advanced Composite Solid Electrolytes for Lithium Batteries: Filler Dimensional Design and Ion Path Optimization

Composite solid electrolytes are considered to be the crucial components of all-solid-state lithium batteries, which are viewed as the next-generation energy storage devices for high energy density and long working life. Numerous studies have shown that fillers in composite solid electrolytes can effectively improve the ion-transport behavior, the essence of which lies in the optimization of the ion-transport path in the electrolyte. The performance is closely related to the structure of the fillers and the interaction between fillers and other electrolyte components including polymer matrices and lithium salts. In this review, the dimensional design of fillers in advanced composite solid electrolytes involving 0D–2D nanofillers, and 3D continuous frameworks are focused on. The ion-transport mechanism and the interaction between fillers and other electrolyte components are highlighted. In addition, sandwich-structured composite solid electrolytes with fillers are also discussed. Strategies for the design of composite solid electrolytes with high room temperature ionic conductivity are summarized, aiming to assist target-oriented research for high-performance composite solid electrolytes.     

锂/硫电池的研究现状、问题及挑战

锂/硫电池是以金属锂为负极、单质硫为正极而构筑的二次电池体系。锂/硫电池具有高的理论能量密度 (2600 Wh/kg), 成为最具发展潜力的高能化学电源体系。但这种基于溶解?沉积反应的锂/硫电池体系仍面临一些无法避免的问题, 包括金属锂负极的显著结构变化、硫正极材料存在的活性物质利用率低和循环性能差等缺点, 制约了锂/硫电池的发展。本文结合近年来关于锂/硫电池的突破进展, 简要阐述了锂/硫电池的研究现状、问题及面临的挑战。     

全固态薄膜锂充电电池的研究进展

全固态薄膜锂充电电池由于安全可靠性强、能量密度大、工作电压高、循环寿命长等诸多优点已经成为微型电子器件匹配电源的良好选择.阴极、阳极、固体电解质材料是全固态薄膜锂充电电池的重要组成部分,对于其开发和研究十分重要.综述了目前应用较多的阴极、阳极及固体电解质材料,并阐述了其物理特性、电化学性能和主要的制备方法;电池结构设计同样影响着整个电池的性能,介绍了电池结构对充放电特性的影响,且展望了其今后的研究热点和发展方向.