Taming Solvent-Solute Interaction Accelerates Interfacial Kinetics in Low-Temperature Lithium-Metal Batteries

Lithium (Li)-metal batteries promise energy density beyond 400 Wh kg(-1), while their practical operation at an extreme temperature below -30 degrees C suffers severe capacity deterioration. Such battery failure highly relates to the remarkably increased kinetic barrier of interfacial processes, including interfacial desolvation, ion transportation, and charge transfer. In this work, the interfacial kinetics in three prototypical electrolytes are quantitatively probed by three-electrode electrochemical techniques and molecular dynamics simulations. Desolvation as the limiting step of interfacial processes is validated to dominate the cell impedance and capacity at low temperature. 1,3-Dioxolane-based electrolyte with tamed solvent-solute interaction facilitates fast desolvation, enabling the practical Li|LiNi0.5Co0.2Mn0.3O2 cells at -40 degrees C to retain 66% of room-temperature capacity and withstand remarkably fast charging rate (0.3 C). The barrier of desolvation dictated by solvent-solute interaction environments is quantitatively uncovered. Regulating the solvent-solute interaction by low-affinity solvents emerges as a promising solution to low-temperature batteries.

Automated summary

Lithium (Li)-metal batteries suffer severe capacity deterioration at extreme temperatures due to increased kinetic barrier of interfacial processes. This study quantitatively probes the interfacial kinetics in three different electrolytes and reveals that desolvation is the limiting step dominating the cell impedance and capacity at low temperature. The use of a 1,3-dioxolane-based electrolyte with tamed solvent-solute interaction facilitates fast desolvation and enables practical Li|LiNi0.5Co0.2Mn0.3O2 cells at -40 degrees C to retain 66% of room-temperature capacity and withstand fast charging rates. The barrier of desolvation dictated by solvent-solute interaction environments is quantitatively uncovered, and regulating this interaction emerges as a promising solution to low-temperature batteries.