LiNiVO4–promising thin films for use as anode material in microbatteries

Thin films of lithium nickel vanadates (LixNiVyOz) have been prepared by radio frequency magnetron sputtering from a LiNiVO4 target. The discharge gas was either pure argon or a mixture of argon and oxygen. The deposition rates as well as the composition and morphology of the films strongly depend on the sputtering parameters. For a total pressure of 1 Pa, the V/Ni atomic ratio varies between 0.75 for films developed in a pure argon plasma and 1.65 when the partial pressure of oxygen is 100 mPa. The thin film containing the two types of transition metals in an equiatomic ratio (Li1.1NiVO4) has given the best electrochemical properties as an anode displaying a specific capacity that became stable at 1000 mAh/g after three cycles, which is at least as high as for bulk material.