Analysis of Capacity Fade from Entropic Heat Coefficient of Li[NixCoyMnz]O-2/Graphite Lithium Ion Battery

作者:Yun Feng ling; Jin Wei ren; Tang Ling; Li Wencheng; Pang Jing; Lu Shi gang*
来源:Journal of the Electrochemical Society, 2016, 163(5): A639-A643.
DOI:10.1149/2.0311605jes

摘要

The entropic heat coefficient (i.e., dU/dT) of Li[NixCoyMnz]O-2/graphite before and after cycle was determined using the electrochemical thermodynamics measurements (ETMs) tool. DU/dT could be attributed to the individual electrodes for this notable battery and associates with the Li-intercalated state. Lithium intercalation number in negative and positive electrode was calculated and compared for the battery before and after cycle, respectively. Results show that the trend of dU/dT with Li-intercalated state before and after cycle is basically consistent except for the initial and maximum state. DU/dT has the typical characteristics of stage structures of graphite. In particular, these changes is independent of the battery aging. Negative electrode has greater Li-intercalated depth loss than that of positive electrode after cycle, thus negative electrode is the dominant degradation factor of the battery.