Lithium Metal Negative Electrode for Batteries with High Energy Density: Lithium Utilization and Additives

Metallic lithium is considered to be the ultimate negative electrode for a battery with high energy density due to its high theoretical capacity. In the present study, to construct a battery with high energy density using metallic lithium as a negative electrode, charge/ discharge tests were performed using cells composed of LiFePO4 and metallic lithium at various lithium utilization values. A relationship was observed between utilization and cycle performance, and the degradation behavior of metallic lithium was evaluated by cross-sectional FE-SEM observations. We also investigated the effects of additives in the electrolyte and found that FEC and VC effectively improved cycle performance. (C) The Author(s) 2020. Published by ECSJ.