Local-high-concentration molecular catalysts enabled by covalent organic frameworks for rechargeable Li | |SOCl₂...

Rechargeable Li | |SOCl₂•I₂ batteries, with their high specific energy, rely fundamentally on molecular catalysts to enable efficient redox processes. However, the inadequate accumulation of molecular catalysts at the positive electrode interface critically impairs their catalytic performance, especially under high specific capacity conditions. Herein, we propose to create localized high-concentration environments of molecular catalysts by using covalent organic frameworks with well-aligned pore structures and tailored functionality, which simultaneously enhance micropore accessibility (η = 82.6%) and capture ability (E_ads = -0.78 eV) of molecular catalyst, far surpassing conventional porous carbon (η = 38%, E_ads = -0.33 eV). This approach enables Li | |SOCl₂•I₂ battery to achieve stable 500 mAh/g over 1200 cycles and 2000 mAh/g over 80 cycles with an average Coulombic efficiency of up to 99.5%. Even at a low I₂ concentration of 7 mg/mL, the Li | |SOCl₂•I₂ battery using covalent organic frameworks delivers a high discharge capacity of 5000 mAh/g. The covalent organic frameworks-mediated localization of molecular catalysts enhances reaction kinetics and pathways, contributing to a substantial improvement in the overall performance of the Li | |SOCl₂•I₂ battery system.