Microstructure and electrochemical properties of iron oxide film fabricated by aerosol deposition method for lithium ion battery

The microstructure and electrochemical properties of Fe2O3 films, which are fabricated by an aerosol deposition (AD) method, are investigated in this study. For the high rate capability in Li ion battery, not only the nano-size grain but also the path for electrolyte is required in thin/thick electrode films. The microstructure is formed in Fe2O3 AD films. The Fe2O3 AD film shows the dense microstructure and the small grain size of a few nanometers. In particular, the space for electrolyte is also observed in the Fe2O3 AD film which has the dense microstructure. In addition, the AD method has the excellent deposition speed (1-10 min for 1 μm, 10 × 10 cm2). In this manuscript, it is indicated that an Fe2O3 AD film has the excellent rate capability because of the self-fitted microstructure, which shows the path for electrolyte as well as the nano-size grains. In addition, the high capacity of 150 μAh cm−2 is also observed at the Fe2O3 AD film (the current density of 50 μA cm−2, the film thickness: 300 nm).