储能科学与技术 ›› 2023, Vol. 12 ›› Issue (8): 2457-2481.doi: 10.19799/j.cnki.2095-4239.2023.0262

• 储能材料与器件 • 上一篇    下一篇

锂离子电池单颗粒动力学表征方法综述

左安昊(), 方儒卿, 李哲()   

  1. 清华大学车辆与运载学院,北京 100084
  • 收稿日期:2023-04-25 修回日期:2023-06-02 出版日期:2023-08-05 发布日期:2023-08-23
  • 通讯作者: 李哲 E-mail:zah20@mails.tsinghua.edu.cn;zhe_li@tsinghua.edu.cn
  • 作者简介:左安昊(1998—),男,博士研究生,研究方向为电池材料单颗粒动力学测试方法,E-mail:zah20@mails.tsinghua.edu.cn
  • 基金资助:
    国家自然科学基金项目(U1864214)

Kinetic characterization of electrode materials for lithium-ion batteries via single-particle microelectrodes

Anhao ZUO(), Ruqing FANG, Zhe LI()   

  1. School of Vehicle and Mobility, Tsinghua University, Beijing 100084, China
  • Received:2023-04-25 Revised:2023-06-02 Online:2023-08-05 Published:2023-08-23
  • Contact: Zhe LI E-mail:zah20@mails.tsinghua.edu.cn;zhe_li@tsinghua.edu.cn

摘要:

传统的电池材料性能测试方法将材料制成半电池或全电池,并根据电池性能(如能量密度、倍率性能、体积形变等)反推材料性能,如实际克容量、平衡电势、扩散系数、离子/电子电导、交换电流密度、体积膨胀率等。该方法存在以下两方面问题:第一,误差显著:电池含有多种材料,单体性能测试结果受到不同材料各自热/动力学过程的混合影响,不能反映单一材料性能;第二,浪费巨大:电池单体容量远超单个粉体颗粒容量,以单体为对象进行材料性能测试将浪费大量物料、电能、时间。综合比较不同尺度电池研究对象后,本工作认为直接对单个颗粒开展电化学测试既剥离了电极中非活性物质及孔隙的影响,又保留了材料缺陷、微观结构等特性,是目前表征材料动力学性能的理想方案。本工作围绕锂离子电池单颗粒动力学表征方法,梳理了单颗粒尺度测试技术,并在测试体系、测试对象、对象可选择性、嵌锂态控制、外部应力等方面综合比较了各种方法。基于此,从材料性能表征与材料参数获取两方面论述了基于接触式单颗粒微电极和连接式单颗粒微电极的动力学表征方法。最后,综述了单颗粒动力学表征方法与其他材料表征方法的联用案例以及发展方向。

关键词: 锂离子电池, 单颗粒微电极, 动力学表征, 参数获取

Abstract:

Conventional methods to test the battery materials' performance involve fabricating half/full cells and inferring material performance based on statistical results drawn from battery performance, such as energy density, rate capability, volume deformation, etc. These parameters are used to deduce material properties, including ionic/electronic conductivity, actual specific capacity, and exchange current density. However, such methods are marred by several issues. Firstly, significant errors are introduced as nonactive substances and the combined thermodynamic/kinetic processes influence individual material testing. These factors result in inaccurate and misleading performance reflections of active material. Secondly, testing the material performance on cells significantly wastes materials, energy, and time due to the far-exceeding cell capacity compared to individual particles. After comprehensively comparing different research objects for batteries, this paper proposed that direct electrochemical testing of single particles is currently the optimal approach for characterizing the kinetic performance of materials. This approach eliminated the influence of nonactive substances and pores in the porous electrode while retaining characteristics such as material defects, microstructure, etc. This paper reviewed various techniques for testing at the single-particle scale in lithium-ion batteries. In addition, a comparative analysis was conducted on aspects such as testing system, testing objects, object selectivity, lithiation state control, external stress, etc. Additionally, kinetic characterizations using contact-based and integrated single-particle microelectrodes were discussed, highlighting their effectiveness in performance characterization and parameter estimation. Finally, the paper discussed the combined use of single-particle kinetic characterization with other material characterization methods, as well as their future directions.

Key words: lithium-ion battery, single-particle microelectrode, kinetics characterization, parameter estimation

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