Carbon-Coated Current Collectors for High-Power Lithium-Ion Secondary Batteries

The goal of this project is to develop a viable C-coating process of the current collector in order to improve the overall power performance of the electrode of Li-ion batteries. Two major parts of research works toward this goal were carried out. 1 Al and Cu foils were subjected to high-temperature chemical vapor deposition T-CVD to produce surface C-coating, and the resulting foils were used as current collectors for LiFePO4 and Li4Ti5O12. The C-coating remarkably enhanced the power performance of both electrodes. The enhancement was attributed to a combination of two factors--removal of the native oxide layer and modification of surface hydrophobicity--both of which reduced the resistance at the current-collector active layer interface. 2 A low-temperature plasma-assisted chemical vapor deposition PA-CVD vacuum chamber was built and tested. The design of the chamber allows for roll-to-roll plasma treatment of metal foils under vacuum condition, and it is ready for carry out low-temperature coating processes in the next-year phase of research.