Hydrogen-Bonded Organic Framework to Upgrade Cycling Stability and Rate Capability of Li-CO2 Batteries

Elaborately designed multifunctional electrocatalysts capable of promoting Li⁺ and CO₂ transport are essential for upgrading the cycling stability and rate capability of Li-CO₂ batteries. Hydrogen-bonded organic frameworks (HOFs) with open channels and easily functionalized surfaces hold great potential for applications in efficient cathodes of Li-CO₂ batteries. Herein, a robust HOF_S (HOF-FJU-1) is introduced for the first time as a co-catalyst in the cathode material of Li-CO₂ batteries. HOF-FJU-1 with cyano groups located periodically in the pore can induce homogeneous deposition of discharge products and accommodate volumetric expansion of discharge products during cycling. Besides, HOF-FJU-1 enables effective interaction between Ru⁰ nanoparticles and cyano groups, thus forming efficient and uniform catalytic sites for CRR/CER. Moreover, HOF-FJU-1 with regularly arranged open channels are beneficial for CO₂ and Li⁺ transport, enabling rapid redox kinetic conversion of CO₂. Therefore, the HOF-based Li-CO₂ batteries are capable of stable operation at 400 mA g⁻¹ for 1800 h and maintain a low overpotential of 1.96 V even at high current densities up to 5 A g⁻¹. This work provides valuable guidance for developing multifunctional HOF-based catalysts to upgrade the longevity and rate capability of Li-CO₂ batteries.