Abstract
This piper reports that spinel-phase Li 4 Ti 5 O 12 thin films were successfully grown by radio frequency (rf) magnetron sputtering on an Au/Ti/SiO 2 /Si substrate. In this process, the buffer layer of gold serves as a template for the texture growth of Li 4 Ti 5 O 12 film. The growth temperature affects the microstructure and electrochemical characteristics of the deposited films. In our study, the spinel phase of Li 4 Ti 5 O 12 appears at deposition temperatures above 500°C. The redox peaks in the cyclic voltammetry of the Li/Li 4 Ti 5 O 12 cell approach the typical value of 1.55 V as raising the deposition temperature. Moreover, the influences of the surface morphology of the film on the capacity were studied. They show that a columnar structure with high porosity was obtained in the film deposited above 650°C. The columnar grains with good crystallinity of the deposited Li 4 Ti 5 O 12 enhance die capacity of the electrode. In this work, the capacity of 53 μAh/cm 2 μm can be attained for the film with a thickness of 230 nm deposited at 700°C. This study sheds light on the realization of a solid-state thin film battery and provides a possible solution of electrical power for a mobile integrated circuit chip. © 2005 The Electrochemical Society. All rights reserved.