Anionic Coordination Manipulation of Multilayer Solvation Structure Electrolyte for High‐Rate and Low‐Temperature Lithium Metal Battery

Abstract

AbstractChallenges from high‐energy‐density storage applications have boosted the pursuit of designing high‐rate and low‐temperature lithium (Li) metal batteries (LMBs). Formulating high‐concentration electrolytes (HCEs) with a high transference number (t+) is an alternative solution to satisfy these demands. However, the implementation of HCEs is impeded by their lower ionic conductivity, higher viscosity, poorer wettability, and higher melting point, which are harmful to the practical applications. Herein, an anionic coordination manipulation strategy is proposed to break the constraints presented by HCEs. By manipulating the anionic species with different coordinating abilities, a high t+ up to 0.9 can be achieved even in the low‐concentration electrolytes of 1 mol L−1. By further forming a multilayer solvation structure in the anion manipulated electrolyte using non‐polar diluents, high Li Coulombic efficiency superior to 99% can be maintained under a high current density of 3 mA cm−2, and much‐improved performance is also demonstrated in high‐loading Li metal pouch cells. Furthermore, when applying multilayer solvated structure in electrolyte engineering, Li metal anodes at subzero temperature and LMBs at 0 °C also exhibit impressive cycling stability. This work provides a new guideline for designing advanced electrolytes for high‐rate LMBs under practical conditions.