Film-shaped sol–gel Li4Ti5O12 electrode for lithium-ion microbatteries

Homogeneous and transparent film-shaped spinel Li4Ti5O12 electrodes on gold coated quartz were synthesized 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 TiO2 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 of Li4Ti5O12 electrodes obtained with the higher lithium content composition.

► Nanostructured Li4Ti5O12 thin film electrodes for Li-ion microbatteries were developed. ► Li4Ti5O12 thin films were produced by sol–gel method and dip-coating process. ► Composition Li/Ti = 6/5 presents single face-centered cubic spinel phase Li4Ti5O12. ► Good galvanostatic cycling and very flat discharge–charge were obtained. ► Li4Ti5O12 thin films are potential anode materials for lithium-ion microbatteries.