Electrolyte Design for Anode-Free Lithium Metal Batteries

Abstract

Current lithium-ion batteries (LIBs) are approaching their energy density limits and thus may not keep up with the ever-increasing demand for higher specific energy density in today’s energy storage and power applications. Anode-free lithium metal batteries (AFLMBs) utilize the full theoretical capacity of Li metal anode (3860 mAh g-1, ten times higher than lithiated graphite) and offer lower cost and better safety than cells with Li excess. However, due to the low efficiency of Li deposition and stripping, AFLMBs suffer from rapid capacity loss.In this presentation, we will discuss a unique coin cell configuration design with high compression for AFLMBs. The high pressure leads to more stable cycling performance, providing a more accurate assessment of AFLMBs.1 A carbonate-glyme hybrid electrolyte for AFLMB is demonstrated with a capacity retention of 73% for 50 cycles. The hybrid electrolyte possesses a unique solvation structure, where diglyme solvates both Li-ions and film-forming additive, while carbonates dilute the mixture, enabling facile ion migrations.2 C. Zhou, A. J. Samson, M. A. Garakani, and V. Thangadurai, J. Electrochem. Soc., 168, 060532 (2021).C. Zhou et al., Energy Storage Mater., 42, 295–306 (2021) https://doi.org/10.1016/j.ensm.2021.07.043.