Electrochemical characteristics and cycle performance of LiMn2O4/a-Si microbattery

A LiMn2O4 thin film and an amorphous Si (a-Si) thin film were prepared by radio-frequency (rf) magnetron sputtering. Each thin film was electrochemically evaluated by cyclic voltammetry (CV) and galvanostatic cycling. The rate of capacity fade on cycling was monitored as a function of the voltage window and current density. This was compared with the cycle performance of cathode and anode using two kinds of electrolyte, I M LiPF6 in EC/DMC and PC, for 100 cycles. It was found that the discharge capacity of optimized LiMn2O4/a-Si full-cell reached 24 muAh(cm(2)-mum) in the first cycle, and a reversible capacity of about 16 muAh/(cm(2) mum) was still maintained after 100 cycles. In a voltage window of 3.0-4.2 V, LiMn2O4/a-Si full-cell exhibits relatively stable cycle performance compared to a voltage window of 2.75-4.2 V (C) 2003 Elsevier B.V. All rights reserved.