The Characterization of LiMn2O4 Thin Film Cathode for Lithium Rechargeable Microbattery Prepared by Liquid Source Misted Chemical Deposition

Liquid source misted chemical deposition was used to fabricate LiMn2O4 film as a cathode for lithium rechargeable microbatteries. The effect of crystallization temperature on the film properties was investigated by X‐ray diffraction (XRD), Raman spectroscopy (RS), X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), cyclic voltammetry (CV), and charge/discharge experiments. When the heat treatment for crystallization of the as‐deposited film was carried out at 800 °C in a rapid thermal apparatus (RTA) in an oxygen atmosphere for 5 min, the structural and compositional purity, and the electrochemical activity of the deposited film, were optimized. The LiMn2O4 films prepared by this method exhibited much better electrochemical rechargeability than those deposited by other techniques, such as sputtering, laser ablation, sol–gel coating, etc. The prepared film exhibits an initial discharge capacity of 62.5 μA h cm–2 μm–1 and a low capacity fade of 8.0 % over 100 cycles. Homogeneous LiMn2O4 films are produced by LSMCD (liquid source misted chemical deposition). Sectional SEM analysis on as deposited films show no discontinuation (see Figure). Annealing the deposit at 800 °C produces films exhibiting high initial discharge capacity of 62.5 μA h cm–2 μm–1 and good capacity retention of 92% over 100 cycles.