物理化学学报 >> 2021, Vol. 37 >> Issue (1): 2006021.doi: 10.3866/PKU.WHXB202006021

所属专题: 金属锂负极

综述 上一篇    下一篇

锂金属负极的挑战与改善策略研究进展

刘凡凡1, 张志文1, 叶淑芬1, 姚雨1, 余彦1,2,*()   

  1. 1 中国科学技术大学,中国科学院能量转换材料重点实验室,材料科学与工程系,合肥微尺度物质科学国家研究中心,合肥 230026
    2 中国科学院洁净能源创新研究院,辽宁 大连 116023
  • 收稿日期:2020-06-10 录用日期:2020-07-01 发布日期:2020-07-08
  • 通讯作者: 余彦 E-mail:yanyumse@ustc.edu.cn
  • 作者简介:余彦,教授,博士生导师,国家杰出青年基金获得者,英国皇家化学会会士,Journal of Power Sources副主编。主要从事高性能锂离子电池、钠离子电池、锂硫电池等关键电极材料的设计、合成及储能机制研究
  • 基金资助:
    国家重点研发计划(2018YFB0905400);国家自然科学基金(51622210);国家自然科学基金(51872277);国家自然科学基金(U1910210);中国科学院洁净能源创新研究院合作基金(DNL180310);中央高校基本科研基金(Wk2060140026)

Challenges and Improvement Strategies Progress of Lithium Metal Anode

Fanfan Liu1, Zhiwen Zhang1, Shufen Ye1, Yu Yao1, Yan Yu1,2,*()   

  1. 1 Hefei National Laboratory for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, Hefei 230026, China
    2 Dalian National Laboratory for Clean Energy (DNL), Chinese Academy of Sciences (CAS), Dalian 116023, Liaoning Province, China
  • Received:2020-06-10 Accepted:2020-07-01 Published:2020-07-08
  • Contact: Yan Yu E-mail:yanyumse@ustc.edu.cn
  • About author:Yan Yu. Email: yanyumse@ustc.edu.cn; Tel.: +86-551-63607179
  • Supported by:
    the National Key R & D Research Program of China(2018YFB0905400);the National Natural Science Foundation of China(51622210);the National Natural Science Foundation of China(51872277);the National Natural Science Foundation of China(U1910210);the Dalian National Laboratory for Clean Energy (DNL) Cooperation Fund, the CAS(DNL180310);the Fundamental Research Funds for the Central Universities, China(Wk2060140026)

摘要:

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。

关键词: 锂金属负极, 三维基体, 电解液, 添加剂, 人造SEI, 锂金属电池

Abstract:

The Li metal anode is considered the most promising anode for next-generation high energy density batteries owing to its high theoretical capacity and low electrode potential. The development of batteries with high energy density is essential to meet the growing demand for energy storage devices in the modern world. However, the Li metal anode has operational problems. The high activity of Li causes dendritic growth during the cycling process, which leads to the cracking of the SEI (solid-electrolyte interphase), increased side reactions, and formation of dead Li. Furthermore, if the growth of Li dendrites is left uncontrolled, it can penetrate the separator and create a short-circuit accompanied by thermal runaway. Additionally, the complete utilization of active Li is challenged by the infinite volume expansion of the Li anode. To improve the application scope of Li metal batteries, it is imperative to develop advanced strategies for inhibiting Li dendritic growth, enhancing the stability of the SEI, reducing the accumulation of dead Li, and buffering the volume expansion. Understanding the mechanisms and models of Li nucleation and growth provides insight into solving these problems. This review summarizes some of the important models of Li nucleation and growth such as the surface nucleating model, charge-induced model, SEI model, and deposition/dissolution model. These models aid comprehension of the Li nucleation and growth process under various conditions. This review also discusses the strategies explored in the literature for improving the electrodes (such as three-dimensional (3D) matrix), electrolyte, SEI, and separator to realize uniform deposition of Li and improved utilization of Li. The 3D matrix strategy for improving the electrode design explores various matrices including graphene-based, carbon fiber-based, porous metal-based, and powder-based for buffering the volume expansion and reducing the local current density. To improve the electrolyte, concentrated lithium salts and functional additives are employed to stabilize the SEI and inhibit dendritic growth by regulating the chemical composition of SEI and inducing the deposition of Li. With respect to improving the design of the SEI, strategies for the construction of inorganic or organic components with high ionic conductivity and stable structure are explored for even distribution of Li ions and to avoid SEI rupture. This can reduce electrolyte consumption and dead Li formation. The modification of the separator by functional nanocarbon layer can control the direction of dendritic growth, thereby preventing the penetration of dendrites into the separator and achieving a uniform Li deposition layer. Finally, all solid state Li metal batteries (ASSLMBs) are discussed that utilize ceramic and polymer electrolytes owing to high safety of the solid state electrolyte. Therefore, reducing the interfacial resistance and suppressing dendritic growth between the Li anode and the electrolyte is key for the practical applications of ASSLMBs. Overall, this review provides a summary and outlook for promoting the practical applications of Li metal batteries.

Key words: Li metal anode, 3D matrix, Electrolyte, Additive, Artificial SEI, Li metal battery

MSC2000: 

  • O646