超音波噴霧ミストCVD法によるリチウム系酸化物の成膜

抄録

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.