Low-Temperature and Fast-Charging Lithium Metal Batteries Enabled by Solvent–Solvent Interaction Mediated Electrolyte
Akang Huang, Zheng Ma, Pushpendra Kumar, Honghong Liang, Tao Cai, Fei Zhao, Zhen Cao, Luigi Cavallo, Qian Li, Jun Ming
Abstract
Lithium metal batteries utilizing lithium metal as the anode can achieve a greater energy density. However, it remains challenging to improve low-temperature performance and fast-charging features. Herein, we introduce an electrolyte solvation chemistry strategy to regulate the properties of ethylene carbonate (EC)-based electrolytes through intermolecular interactions, utilizing weakly solvated fluoroethylene carbonate (FEC) to replace EC, and incorporating the low-melting-point solvent 1,2-difluorobenzene (2FB) as a diluent. We identified that the intermolecular interaction between 2FB and solvent can facilitate Li + desolvation and lower the freezing point of the electrolyte effectively. The resulting electrolyte enables the LiNi 0.8 Co 0.1 Mn 0.1 O 2 ||Li cell to operate at −30 °C for more than 100 cycles while delivering a high capacity of 154 mAh g –1 at 5.0C. We present a solvation structure and interfacial model to analyze the behavior of the formulated electrolyte composition, establishing a relationship with cell performance and also providing insights for the electrolyte design under extreme conditions.