Combinational effects of oxygen plasma irradiation and annealing on Li Mn2 O4 thin film cathodes
Journal
Journal of the Electrochemical Society
Journal Volume
158
Journal Issue
3
Pages
A262-A265
Date Issued
2011
Author(s)
Abstract
Polycrystalline thin films are deposited by radio frequency (rf) magnetron sputtering followed by air annealing at 600 and . The films are then treated with an rf driven oxygen plasma. The crystallographic structures and surface morphologies of the thin films are studied. Plasma treatments induce different trends of microstructural evolution in 600 and annealed films. The microstructural evolutions are induced by the combination effects of plasma treatments and air annealing. The results can be interpreted by the atomic relaxation and resputtering models. For both high and low temperature annealed films, a well-tuned plasma treatment can result in films with a dense subsurface microstructures and a grain size of , which shows a greatly enhanced electrochemical performances. Under optimal treatments conditions, the electrochemical performances of the films can be greatly improved. The treated samples are tested under harsh conditions, including deep discharge to and cycling at elevated temperature of , and such subsurface structure is found to suppress the development of rock-salt phase.
SDGs
Type
journal article