化工学报 ›› 2020, Vol. 71 ›› Issue (8): 3710-3721.DOI: 10.11949/0438-1157.20200279

• 能源和环境工程 • 上一篇    下一篇

锂离子电池大电流放电过程模拟研究

董缇1(),彭鹏1,王亦伟1,曹文炅1,郑耀东2,雷博3,蒋方明1()   

  1. 1.中国科学院广州能源研究所, 中国科学院可再生能源重点实验室, 广东省新能源和可再生能源研究开发与应用 重点实验室, 广东 广州 510640
    2.中国南方电网有限责任公司,广东 广州 510063
    3.南方电网科学院有限责任公司,广东 广州 510063
  • 收稿日期:2020-03-18 修回日期:2020-05-07 出版日期:2020-08-05 发布日期:2020-08-05
  • 通讯作者: 蒋方明
  • 作者简介:董缇(1989—),男,博士,助理研究员,dongti@ms.giec.ac.cn
  • 基金资助:
    国家重点研发计划项目(2018YFB0905300);广东省新能源和可再生能源研究开发与应用重点实验室项目(Y909jh1)

Simulation on lithium ion battery discharge process with large current

Ti DONG1(),Peng PENG1,Yiwei WANG1,Wenjiong CAO1,Yaodong ZHENG2,Bo LEI3,Fangming JIANG1()   

  1. 1.Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, Guangdong, China
    2.China Southern Power Grid, Guangzhou 510063, Guangdong, China
    3.Electric Power Research Institute, China Southern Power Grid, Guangzhou 510063, Guangdong, China
  • Received:2020-03-18 Revised:2020-05-07 Online:2020-08-05 Published:2020-08-05
  • Contact: Fangming JIANG

摘要:

随着锂离子电池的广泛应用,电池以更大功率、更高倍率运行的需求日益迫切,探索锂离子电池大电流运行时的电-热行为及内部关键参数演化十分必要。建立了锂离子电池的电化学-热(ECT)模型和电池材料的热滥用模型,模拟了方形单层LiCoO2/C电芯在不同放电电流下的电-热行为,对比分析了电池分别以1C和14C倍率放电时电池内部关键电化学参数的演化过程。结果表明:随着放电电流增加,电池内部积聚的热量会引发材料的放热反应,有引发电池热失控的可能性;大电流放电过程电解液中锂离子浓度、输运电流密度、过电势、电解质电势和固相颗粒表面的锂离子浓度波动较大,在电池内部相关区域形成了明显的浓度差、密度差和电势差。

关键词: 锂离子电池, 大电流放电, 传热, 化学反应, 传递过程, 电化学参数演化

Abstract:

With the widespread application of lithium-ion batteries, the demand for batteries to operate at higher power and higher rates is becoming more and more urgent. It is necessary to explore the electro-thermal behavior and internal key parameters of lithium-ion batteries at high current operation. In this paper, a combined model of the electrochemical- thermal (ECT) coupling model and the thermal model for abusive reaction of battery materials is established. The electrical-thermal behaviors of a prismatic single-layer LiCoO2/C cell during discharge processes of various C-rates are simulated. The key electrochemical parameters and their dynamics for the cell during 1C and 14C discharge processed are analyzed and compared. The results show that with the increase of discharge current, heat accumulation in the battery will trigger the exothermic reactions of battery materials, making the battery vulnerable to thermal runaway. Besides, the concentration of Li-ion in the electrolyte, the transfer current density, the over potential, the electrolyte potential and the lithium concentration at the surface of solid particles fluctuate greatly during high C-rate discharge processes, leading to significant differences of species concentration, density and electric potential in the relevant regions inside the battery.

Key words: Li-ion battery, large current discharge, heat transfer, chemical reaction, transport processes, evolution of electrochemical parameters

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