Superior Li<sup>+</sup> Kinetics by “Low-Activity-Solvent” Engineering for Stable Lithium Metal Batteries
Haifeng Tu, Zhigang He, Ao Sun, Farwa Mushtaq, Linge Li, Zhicheng Wang, Yaping Kong, Rong Huang, Hongzhen Lin, Wanfei Li, Fangmin Ye, Pan Xue, Meinan Liu
Abstract
The structure of solvated Li + has a significant influence on the electrolyte/electrode interphase (EEI) components and desolvation energy barrier, which are two key factors in determining the Li + diffusion kinetics in lithium metal batteries. Herein, the “solvent activity” concept is proposed to quantitatively describe the correlation between the electrolyte elements and the structure of solvated Li + . Through fitting the correlation of the electrode potential and solvent concentration, we suggest a “low-activity-solvent” electrolyte (LASE) system for deriving a stable inorganic-rich EEI. Nano LiF particles, as a model, were used to capture free solvent molecules for the formation of a LASE system. This advanced LASE not only exhibits outstanding antidendrite growth behavior but also delivers an impressive performance in Li/LiNi 0.8 Co 0.1 Mn 0.1 O 2 cells (a capacity of 169 mAh g –1 after 250 cycles at 0.5 C).