Electrochemical Quartz Crystal Microbalance Investigations of LiMn[sub 2]O[sub 4] Thin Films at Elevated Temperatures

Abstract

Electrochemical properties of a film in 1 M solution was studied by means of the electrochemical quartz crystal microbalance (QCM) at an elevated temperature (50°C). The film preparation was conducted by an electrostatic spray deposition, which enabled us to obtain a uniform and dense film of on a QCM electrode at low temperature (400°C) to avoid the thermal damage of the quartz. During the galvanostatic charge‐discharge experiment, the mass of electrode specimen increased, most likely due to the formation of a passivation film. If an as‐prepared electrode was only immersed in the solution at 50°C, the mass of electrode decreased steadily, resulting eventually in extinction of the manganese film. Such manganese dissolution was attended by a shift of open circuit voltage from 3.8 to 4.3 V vs. Li, suggesting a formation for as an intermediate in the dissolution reaction. © 2000 The Electrochemical Society. All rights reserved.