Multitarget Design of Fluorinated Carboxylate Electrolytes for Lithium-Metal Batteries under Low Temperature

To improve the lithium metal battery (LMB) performance under low temperature, developing advanced electrolytes is an effective strategy. Compared to traditional ethylene carbonate (EC) electrolytes, carboxylate-based electrolytes are potential candidates for low-temperature batteries due to their inherent advantages of low viscosity and melting point. Further, the fluorination strategy could weaken the interaction between Li⁺ and electrolytes to reduce the transportation barrier of Li⁺. However, the structure-activity relationship of fluorinated carboxylate molecules is still unclear, and insight is lacking at the molecular level. To tackle this issue, theoretical calculations were employed to screen fluorinated carboxylates with the variables of the number and position of fluorinated groups and alkyl chain length, meeting the requirement of a high Li⁺ diffusion coefficient (D_Li+) and low desolvation energy (DSE) barrier for fast Li⁺ transportation kinetics. Finally, two fluorinated carboxylates were screened for LMBs at low temperature, aiming to accelerate the electrolyte design from a theoretical point of view.