Increasing the operation voltage of LiCoO2 (LCO) is a direct way to enhance the energy density of the Li-ion batteries. However, overcharging the cells results in a very fast degradation of cycling stability due to the irreversible changes in the electrode structure, and formation of an unstable solid-electrolyte interface layer. In this work, Ag thin film was prepared on commercial LCO cathode by using magnetron sputtering technique to modify the interface between electrode and the electrolyte. Various electrochemical and physical characterizations were performed to understand the diffusion kinetics of Li ions at the electrode-electrolyte interface. Coating the electrode surface with Ag thin film delivers an improved Coulombic efficiency, which is an indication of suppressed parasitic reactions at the electrode surface. As a result of the surface modification, Ag coated electrode enables an improved electrochemical performance with a much better cycling capability compared to that of the uncoated electrode. This work may lead to new methods on the interface modifications of LCO and other electrode materials to achieve high-capacity Li-ion batteries at high-voltage operations.
5:00 PM–7:00 PM Apr 23, 2019 (US - Arizona)
PCC North, 300 Level, Exhibit Hall C-E