物理化学学报 >> 2022, Vol. 38 >> Issue (6): 2107030.doi: 10.3866/PKU.WHXB202107030

所属专题: 面向电化学储能与转化的表界面工程

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锂离子电池隔膜的功能化改性及表征技术

莫英1, 肖逵逵1, 吴剑芳1, 刘辉2, 胡爱平1, 高鹏1,*(), 刘继磊1,*()   

  1. 1 湖南大学材料科学与工程学院,湖南省清洁能源材料及技术国际联合实验室,先进炭材料及应用技术湖南省重点实验室,长沙 41008
    2 湖南农业大学化学与材料科学学院,长沙 410128
  • 收稿日期:2021-07-16 录用日期:2021-08-19 发布日期:2021-08-26
  • 通讯作者: 高鹏,刘继磊 E-mail:gaop@hnu.edu.cn;liujilei@hnu.edu.cn
  • 作者简介:高鹏,1988年生,毕业于Alfred University-New York State College of Ceramics,现工作于湖南大学。助理教授,硕士生导师,主要研究方向包括缺陷结构设计、电化学储能和先进(原位)表征
    刘继磊,湖南大学教授,博士生导师。主要从事原位谱学电化学表征,高性能电化学储能材料和器件设计、优化和机理研究
  • 基金资助:
    国家自然科学基金(51802091);国家自然科学基金(22075074);湖南省杰出青年科学基金(2020JJ2004);湖南省重大科技专项资助项目(2020WK2013);湖南省创新科研基金(2018RS3046);湖南省自然科学基金(2020JJ5035);湖南省自然科学常德联合基金项目(2018JJ4001)

Lithium-Ion Battery Separator: Functional Modification and Characterization

Ying Mo1, Kuikui Xiao1, Jianfang Wu1, Hui Liu2, Aiping Hu1, Peng Gao1,*(), Jilei Liu1,*()   

  1. 1 College of Materials Science and Engineering, Hunan Joint International Laboratory of Advanced Materials and Technology of Clean Energy, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha 410082, China
    2 School of Chemistry and Material Science, Hunan Agricultural University, Changsha 410128, China
  • Received:2021-07-16 Accepted:2021-08-19 Published:2021-08-26
  • Contact: Peng Gao,Jilei Liu E-mail:gaop@hnu.edu.cn;liujilei@hnu.edu.cn
  • About author:Email: liujilei@hnu.edu.cn (J.L)
    Email: gaop@hnu.edu.cn (P.G)
  • Supported by:
    the National Natural Science Foundation of China(51802091);the National Natural Science Foundation of China(22075074);the Outstanding Young Scientists Research Funds from Hunan Province(2020JJ2004);Major Science and Technology Program of Hunan Province(2020WK2013);the Creative Research Funds from Hunan Province(2018RS3046);the Natural Science Foundation of Hunan Province(2020JJ5035);the Joint Natural Science Project of Hunan-Changde(2018JJ4001)

摘要:

随着锂离子电池在动力和规模化储能等新能源领域应用的不断拓展,具有特殊功能且满足特定使用需求隔膜的设计准则、制备/改性方法及表征技术亟需系统深入研究。针对锂离子电池高性能和高安全性的要求,研究人员已通过结构设计和表面化学改性等策略优化了隔膜的本征特性,并通过系列表征技术探讨了隔膜的功能化改性对锂离子电池电化学性能的影响。基于以上背景,本文从离子传输、枝晶形核与生长、及安全性能三个方面详细探讨了隔膜对电池性能影响的关键因素及其改性方法,并系统总结了隔膜结构、物化特性、力学性能、热学性能以及电化学性能的表征技术,以期为功能隔膜的合理设计,从而优化锂离子电池性能提供理论和实践指导。同时,本文对隔膜未来的进一步研究和发展提出了展望。

关键词: 隔膜, 功能化改性, 锂离子电池, 电化学性能, 表征技术

Abstract:

The design functions of lithium-ion batteries are tailored to meet the needs of specific applications. It is crucial to obtain an in-depth understanding of the design, preparation/ modification, and characterization of the separator because structural modifications of the separator can effectively modulate the ion diffusion and dendrite growth, thereby optimizing the electrochemical performance and high safety of the battery. Moreover, the development and utilization of various characterization techniques are critical and essential in bridging the intrinsic properties of separators and their impacts on the electrochemical performance, which guide the functional modification of the separators. In this review, we systematically summarized the recent progress in the separator modification approaches, primarily focusing on its effects on the batteries' electrochemical performance and the related characterization techniques. Herein, we provide a brief introduction on the separators' classification that mainly includes (modified) microporous membranes, nonwoven mats, and composite membranes; thereafter, we discuss the basic requirements that facilitate the use of membranes as separators, such as good wettability with electrolyte, high permeability for ions, and several intrinsic properties including good thermal stability, electronic insulation, excellent (electro)chemical stability, high mechanical strength, and appropriate thickness/porosity. We then highlight the factors that affect the batteries' performance from the viewpoints of ion diffusion, dendrite growth, and safety, along with the modification approaches. Specifically, the separator should possess high ionic conductivity and uniform ion transmission, which can be achieved by adjusting its composition and through surface modifications. The severe dendrite growth, especially in lithium-metal batteries, could be inhibited by controlling the pore structures, increasing affinity between separator and metal anode, constructing artificial solid electrolyte interphase (SEI), adopting high strength separator, as well as smart design of the separator. The safety issue, which is a major concern that limits battery applications, could be mitigated by increasing the separator's mechanical strength, thermal stability, and shutting the batteries down below thermal runaway temperature through various functionalization approaches. More importantly, the characterizations of the separators' structure, and their mechanical, thermal, and electrochemical properties are systematically summarized, including scanning electron microscope (SEM)/atomic force microscope (AFM) for surface morphology observation, focused ion beam scanning electron microscopic (FIB-SEM)/X-ray tomography (X-ray CT) for 3D structure detection, mercury intrusion porosimetry (MIP)/Brunauer-Emmett-Teller (BET)/Gurley number measurement for pore structure analysis, contact angle and climbing behavior of electrolyte in separators for wettability measurements, characterizations of the separator's tensile behavior, puncture behavior and compression behavior, thermo-gravimetric analysis (TGA)/differential scanning calorimetry (DSC)/infrared thermography (FLIR) for thermal properties test, and the electrochemical methods for determining the separator's electrochemical stability, ionic conductivity, internal resistance, lithium-ion transference number, cycle/rate performance, as well as self-discharge characteristic. These characterizations provide theoretical and practical basis for the rational design of functional separators and optimization of the electrochemical performance of lithium-ion batteries. Finally, we provide the perspectives on several related issues that need to be further explored in this research field.

Key words: Separator, Functional modification, Lithium-ion battery, Electrochemical performance, Characterization technology

MSC2000: 

  • O646