Ion Transport Kinetics in Low‐Temperature Lithium Metal Batteries

The deployment of rechargeable batteries is crucial for the operation of advanced portable electronics and electric vehicles under harsh environment. However, commercial lithium-ion batteries using ethylene carbonate electrolytes suffer from severe loss in cell energy density at extremely low temperature. Lithium metal batteries (LMBs), which use Li metal as anode rather than graphite, are expected to push the baseline energy density of low-temperature devices at the cell level. Albeit promising, the kinetic limitations of standard cell chemistries under subzero operation condition inevitably hamper the cyclability of LMBs, resulting in a severe decline in plating/stripping reversibility and short-circuit hazards due to the dendritic growth. Such performance degradation becomes more pronounced with decreasing temperature, ascribing to sluggish ion transport kinetics during charging/discharging processes which includes Li+ solvation/desolvation, ion transport through bulk electrolyte, as well as ion diffusion within solid electrolyte interphase and bulk electrode materials at low temperature. In this review, the critical limiting factors and challenges for low-temperature ion transport behaviors are systematically reviewed and discussed. The strategies to enhance Li+ transport kinetics in electrolytes, electrodes, and electrolyte/electrode interface are comprehensively summarized. Finally, perspective on future research direction of low-temperature LMBs toward practical applications is proposed.