反应速率对锂硫电池放电性能影响的模型分析
Modeling Analysis on Effect of Reaction Rate on Discharge Performance for Lithium-Sulfur Battery
李鹏 1吕曹 1王飞 1李莎莎 1池永庆1
作者信息
- 1. 太原科技大学化学工程与技术学院,山西太原 030024
- 折叠
摘要
锂硫电池是下一代高能量密度二次电池的重要候选者,其性能改善需深入理解电池中锂、硫间复杂宏观电化学反应过程.基于Newman多孔电极模型思路,结合多孔硫正极特点,合理简化,建立了描述锂硫电池放电过程模型.模型计算与文献实验结果对比表明,模型能较好模拟放电过程趋势、关键特征,验证了模型有效性;不同电化学动力学参数变化下放电结果模拟表明:增大锂离子交换电流密度有利于提高性能;对于正极硫多步电化学反应过程,S8(l)还原反应速率需保持在较高水平上,S82-、S62-还原反应速率不是多步电化学反应的控制步,提高S42-、S22-还原反应速率可以改善电池比容量、功率性能.
Abstract
Lithium-sulfur battery is an important candidate for the next generation of high energy density secondary batteries,and its performance improvement requires a deep understanding of the complex macroscopic electrochemical reaction processes between lithium and sulfur in the battery.In this paper, based on the Newman porous electrode model idea, combined with the typical characteristics of porous sulfur cathode, discharge process model of lithium-sulfur battery was established by reasonable simplification. The comparison of the experimental data and the discharge curve calculated by the model showed that the simulation results could basically represent the trend and key features, and validity of the model was verified. Otherwise,the simulation of discharge results under different electrochemical kinetic parameters showed that increasing the exchange reaction rate of lithium cathode oxidation was beneficial to improve the performance. For positive sulfur multi-step electrochemical reaction process,S8(l) reduction reaction rate need be maintained at a high level,S82- and S62- reduction reaction rates were not control step of multi-step electrochemical reaction, and increasing the S42- and S22- reduction reaction rates could improve the specific capacity performance and power performance of the cell.
关键词
锂硫电池/模型/动力学过程/放电性能/电化学反应速率Key words
Lithium-sulfur battery/Model/Kinetic processes/Discharge performance/Electrochemical reaction rate引用本文复制引用
基金项目
山西省青年科技研究基金项目(201901D211296)
山西省回国留学人员科研资助项目(HGKY2019086)
出版年
2024
NETL
NSTL
万方数据