Film-shaped sol-gel Li_4Ti_5O_(12) electrode for lithium-ion microbatteries

摘要

Homogeneous and transparent film-shaped spinel Li_4Ti_5O_(12) electrodes on gold coated quartz were syn-thesized by sol-gel and a dipping procedure after thermal treatments at 700 C. The influence of the lithium precursor content on the phase composition, structure and electrochemical behavior of this material was studied. Spectral ellipsometry measurements and SEM-EDX analysis indicate an average thickness between 385 and 560 nm. Rutile TiO_2 is detected using grazing incidence X-ray analysis and Micro-Raman in compositions with a lower content of lithium. Good galvanostatic cycling and very flat discharge-charge profiles confirm the high purity ofLi_4Ti_5O_(12) electrodes obtained with the higher lithium content composition.