Cycling-Driven Structural Changes in a Thin-Film Lithium Battery on Flexible Substrate

摘要

Long-term cycling effects on thin-film lithium batteries of 10 _m thick Li/LIPON/LiCoO_2 deposited on a flexible substrate were investigated. Scanning electron microscopic and Raman spectroscopic analysis results revealed that cycling resulted in an in_creased fraction of (003)-oriented grains in originally (101)/(104)-oriented LiCoO_2 films in a hexagonal structure followed by a phase transition to a low temperature spinel phase and shrinkage of the LiCoO_2 films and roughening of the Pt_LiCoO_2 interface, leading to a capacity decline of～ 27% over 1040 cycles. The data contribute to a basic understanding of the structural causes responsible for the internal cell resistance and the cycle life of all-solid-state thin-film batteries.