Abstract
Lithium transition-metal oxides have been recognized as key component materials in lithium-ion secondary batteries. In this article we report the fabrication of lithium manganese oxide (LiMn2O4) thin films with spinel structure, which is a promising candidate material as a positive electrode, by a safe, low-cost, and highly-controllable vapor-phase deposition technique, namely a mist chemical vapor deposition (CVD) method. With the use of lithium acetylacetonato (Li(acac)) and manganese acetylacetonato (Mn(acac)3) as the precursors and their water solution as the reaction source being supplied in the form of small particles, that is, mist formed by being applied ultrasonic power, LiMn2O4 thin films with (111)-face spinel structure was deposited on platinum as well as c-face sapphire substrates at 1000°C. Further reduction in the deposition temperature is expected by using modified reactor configuration with fine-channel structure offering sufficient suppression of the reaction sources onto the substrates. This deposition technique may be applicable for a variety of lithium-based oxide thin films possessing promising potentials to be used in lithium-ion batteries.
