Organocatalytic Lithium Chloride Oxidation by Covalent Organic Frameworks for Rechargeable Lithium‐Chlorine Batteries

Abstract Rechargeable Li−Cl 2 battery is a promising high energy density battery system. However, reasonable cycle life could only be achieved under low specific capacities due to the sluggish oxidation of LiCl to Cl 2 . Herein, we propose an amine‐functionalized covalent organic framework (COF) with catalytic activity, namely COF−NH 2 , that significantly decreases the oxidation barrier of LiCl and accelerates the oxidation kinetics of LiCl in Li−Cl 2 cell. The resulting Li−Cl 2 cell using COF−NH 2 (Li−Cl 2 @COF−NH 2 ) simultaneously exhibits low overpotential, ultrahigh discharge capacity up to 3500 mAh/g and a promoted utilization ratio of deposited LiCl at the first cycle (UR−LiCl) of 81.4 %, which is one of the highest reported values to date. Furthermore, the Li−Cl 2 @COF−NH 2 cell could be stably cycled for over 200 cycles when operating at a capacity of 2000 mAh/g at −20 °C with a Coulombic efficiency (CE) of ≈100 % and a discharge plateau of 3.5 V. Our superior Li−Cl 2 batteries enabled by organocatalyst enlighten an arena towards high‐energy storage applications.