(1. 中山大学 物理科学与工程技术学院,广州 510275;
2. 江门三捷电池实业有限公司 博士后工作站,江门 529000;
3. 东北大学 材料与冶金学院,沈阳 110004)
摘 要: 采用恒电位间歇滴定法(PITT)和电化学阻抗谱技术(EIS)测定锂离子电池正极材料LiFePO4中Li+扩散系数。结果表明:随着嵌锂量的变化,锂离子的扩散系数(
关键字: LiFePO4; 扩散系数; PITT; EIS
(1. School of Physics and Engineering, Sun Yat-Sen University,Guangzhou 510275, China;
2. Postdoctoral Workstation, Jiangmen JJJ Battery Co. Ltd.,Jiangmen 529000, China;
3. School of Materials and Metallurgy, Northeastern University,Shenyang 110004, China)
Abstract:The chemical diffusion coefficient of Li-ion in LiFePO4 cathode material was measured by potentiostatic intermittent titration technique (PITT) and electrochemical impedance spectrum (EIS). The results show that the diffusion coefficient ranges in 10−13−10−16 cm2/s. With the change of Li content the diffusion coefficient appears an extremely large value firstly, latter appears a minimum, then increases. The calculated values by PITT are in agreement with those by EIS.
Key words: LiFePO4; diffusion coefficient; potentiostatic intermittent titration technique(PITT); electrochemical impedance spectrum(EIS)