High rate performances of all-solid-state In/LiCoO2 cells with the Li2S-P2S5 glass-ceramic electrolytes

Composite positive electrodes for all-solid-state In/LiCoO2 cells with Li2S-P2S5 glass-ceramic electrolytes were designed in order to improve rate performances of the cells. In the composite positive electrodes with LiCoO2 in 40 wt.% and the glass-ceramic electrolyte in 60 wt.%, suitable lithium ion conducting paths were formed, and the addition of vapor grown carbon fiber (VGCF) made it easier to form electron-conducting paths. The solid-state cell kept high capacities of about 90 mAh g(-1) even under high current densities of over 1 mA cm(-2) after charged and discharged under low current densities for 100 cycles. It was, thus, suggested that high rate performances of all-solid-state cells were achieved by controlling the mixed state of composite electrodes and the operating condition during charge-discharge cycles. (c) 2006 Elsevier B.V. All rights reserved.