Electrochemical performance of CuO nanocrystal film fabricated by room temperature sputtering

To develop high performance anode materials for thin film batteries, copper oxide (CuO) film is fabricated at room temperature by reactive radio frequency magnetron sputtering. Morphological characterization shows that the CuO film consists of compacted CuO columnar grains of 20 nm in diameter and 200 nm in thickness. The measurement of lithium storage capacity and cyclability of the CuO film show that the first charge capacity of the film is 585 mAh g−1 with an efficiency of 68.3% at a current density of 200 mA g−1. After the 50th cycle, the capacity retention remains as high as 97.4%. The nanostructured CuO film also shows a good rate capability even being cycled at 3000 mA g−1 (5 C), demonstrating that the CuO film can be a promising material as an anode for high performance thin film batteries, especially for thin film battery with amorphous electrolyte.