不同粒径正极材料对锂离子电池性能的影响  

Effects of different particle sizes of cathode materials on electrochemical performance of lithium-ion batteries

作　　者：张小洪 王明灿 班宵汉 田文燕 刘江涛 石斌 袁再芳 ZHANG Xiaohong;WANG Mingcan;BAN Xiaohan;TIAN Wenyan;LIU Jiangtao;SHI Bin;YUAN Zaifang(State Key Laboratory of Advanced Chemical Power Sources,Guizhou Meiling Power Sources Co.,Ltd.,Zunyi Guizhou 563003,China)

机构地区：[1]贵州梅岭电源有限公司特种化学电源全国重点实验室,贵州遵义563003

出　　处：《电源技术》2024年第12期2368-2373,共6页Chinese Journal of Power Sources

基　　金：贵州省科技厅项目(黔科合平台人才-GCC[2023]025、黔科合中引地[2024]008、黔科合基础-[2024]青年399)。

摘　　要：采用三种不同粒径的LiFePO4(LFP)材料与石墨负极复配组装叠片式软包电池,通过粉末电阻率、激光粒度仪及SEM对材料的导电性、粒度和形貌进行了分析,研究了不同粒径对电池电化学性能的影响。结果表明不同粒径大小的正极材料对材料压实密度和电池常温性能影响不大,但具有更小粒径的LFP-W正极材料(初始尺寸小于100 nm)在大倍率下有着显著优势,在3 C下的容量保持率高达74.37%,这得益于更小的颗粒粒径缩短了Li+的迁移路径,提高了Li+的迁移速率;同时LFP-W电池在低温-20℃下的放电容量保持率为64.36%,表现出优异的低温放电能力,因此粒径更小的LFP正极材料具有更优异的倍率性能和低温性能。This article used three different particle sizes of LiFePO4(LFP)materials and graphite negative electrodes to assemble laminated soft pack batteries.The conductivity,particle size,and morphology of the materials were analyzed by powder resistivity,laser particle size analyzer,and SEM,and the influence of different particle sizes on the electrochemical performance of the battery was studied.The results show that positive electrode materials with different particle sizes have little effect on material compaction density and battery room temperature performance.However,LFP-W positive electrode materials with smaller particle sizes(initial size<100 nm)had significant advantages at high rates,with a capacity retention rate of up to 74.37%at 3 C.This is due to the smaller particle size shortening the migration path of Li+and improving its migration rate;At the same time,the discharge capacity retention rate of LFP-Wbattery at low temperature-20℃is 64.36%,demonstrating excellent low-temperature discharge ability.Therefore,LFP positive electrode materials with smaller particle size have better rate performance and low-temperature performance.

关 键 词：锂离子电池 LFP材料 粒径 倍率性能 低温性能 

分 类 号：TM912[电气工程—电力电子与电力传动]