Effect of annealing temperature on electrochemical performance of thin-film LiMn2O4 cathode

Spinel LiMn2O4 thin-film cathodes were obtained by spin-coating the chitosan-containing precursor solution on a Pt-coated silicon substrate followed by a two-stage heat-treatment procedure. The LiMn2O4 film calcined at 700 °C for 1 h showed the highest Li-ion diffusion coefficient, 1.55 × 10−12 cm2 s−1 (PSCA measurement) among all calcined films. It is attributed to the larger interstitial space and better crystal perfection of LiMn2O4 film calcined at 700 °C for 1 h. Consequently, the 700 °C-calcined LiMn2O4 film exhibited the best rate performance in comparison with the ones calcined at other temperatures.