In‐situ Electrochemical Strategy for Preparing Concentrated Electrolytes in Inorganic Mineral Frameworks by Exhausting Solvent Molecules

Abstract

Concentrated electrolytes are attracting attention because of superior electrochemical stability. A typical method to prepare concentrated electrolytes is by adding additional expensive lithium salts to the diluent electrolytes. Herein, a novel quasisolid electrolyte, "concentrated electrolyte-in-mineral frameworks" (CEIMF), was prepared by in-situ exhausting solvent molecules. The obtained electrolyte showed an outstanding lithium-ion transference number of 0.936 and Li-ion conductivity of 3.85 × 10 À 4 S cm À 1 at room temperature, and exhibited excellent electrochemical stability (corresponding to the oxidation voltage of 5.2 V). The LiFePO 4 //Li cells assembled with CEIMF displayed superior long-term cycle stability with an initial discharge specific capacity of 92.7 mA h g À 1 and capacity retention of 72.4 % after 1100 cycles at 1 C. In addition, the cycle performance of LiNi 0.8 Co 0.1 Mn 0.1 O 2 //Li batteries was improved by the use of CEIMF as electrolytes. This work provides a novel in-situ strategy to construct hybrid electrolytes for advanced lithium-ion batteries.