Defect-rich porous carbon as a metal-free catalyst for high-performance Li-CO2 batteries

Abstract

Li-CO2 batteries have been considered as next-generation high-energy-density batteries due to their high theoretical energy density and efficient CO2 fixation. However, the slow reaction kinetics of CO2 reduction and evolution reactions during discharge and charge process severely limits its practical application. Hence, a MOF-5 derived defect-rich porous carbon (c-p-MOF-5) is developed as a durable metal-free catalyst to accelerate CO2 conversion for high-performance Li-CO2 batteries. Benefiting from plentiful pores with large surface area for facilitating CO2 and Li+ diffusion, and rich defect for improving CO2 conversion reactions kinetics, the resultant Li-CO2 battery with c-p-MOF-5 shows excellent electrochemical performance with a high discharge capacity of 22,000 mA h g−1, good rate capability with a low potential gap of 1.7 V at 1000 mA g−1, and high stability over 250 cycles at a current density of 500 mA g−1. This work not only develops an efficient cathode catalyst for Li-CO2 batteries, but also provides a facile method to prepare defect-rich metal-free carbon-based catalysts for Li-CO2 batteries and beyond.