商用LiMn2O4及LiFePO4材料其電化學性能及失效模式分析之研究

The Electrochemical Performance and Fading Mechanism Analysis of Commercial LiMn2O4 and LiFePO4

蘇靜怡(C. Y. Su) ； 吳弘俊(H. C. Wu)

《材料科學與工程》 38卷2期 (2006/06) Pp. 82-87

https://doi.org/10.6409/JMSE.200606.0082

摘要

本研究是將商用LiMn2O4及LiFePO4正極材料搭配MCMB負極材料組成18650型式的全電池進行電化學性能測試及失效模式分析。由實驗得知，較小顆粒的LiMn2O4材料有較佳的大電流放電速率，而導電性差的LiFePO4材料其大電流放電速率最差。另由失效模式分析得知有金屬摻雜的LiMn2O4有較佳的高溫循環壽命和較少的Mn溶解；LiFePO4之金屬溶解量(Fe)比LiMn2O4少十倍，故表現較佳的高溫循環壽命。

關鍵字

電化學性能 ； 失效模式 ； LiFePO4

並列摘要

In this research, the 18650 cells contained commercialized LiMn2O4 or LiFePO4 cathodes and MCMB anodes were made, and the electrochemical performance and fading mechanism of the cells were analyzed. From the results, it could be concluded that LiMn2O4 possessing smaller particle size shows better discharge efficiency at large current, while the low-conductivity LiFePO4 material exhibits the worst performance. In addition, from the analysis of fading mechanism, it reveals the metal-doped LiMn2O4 could provide longer cycle life and less Mn dissolution under high temperature test. Compared to LiMn2O4, LiFePO4 behaves better cyclability in the high temperature environment because of ten times less metal (Fe) dissolution.

並列關鍵字

electrochemical performance ； fading mechanism ； LiFePO4