Engineering the Active Sites of Graphene Catalyst: From CO2 Activation to Activate Li-CO2 Batteries

Abstract

As one of the CO₂ capture and utilization technologies, Li-CO₂ batteries have attracted special interest in the application of carbon neutral. However, the design and fabrication of a low-cost high-efficiency cathode catalyst for reversible Li₂CO₃ formation and decomposition remains challenging. Here, guided by theoretical calculations, CO₂ was utilized to activate the catalytic activity of conventional nitrogen-doped graphene, in which pyridinic-N and pyrrolic-N have a high total content (72.65%) and have a high catalytic activity in both CO₂ reduction and evolution reactions, thus activating the reversible conversion of Li₂CO₃ formation and decomposition. As a result, the designed cathode has a low voltage gap of 2.13 V at 1200 mA g^-1 and long-life cycling stability with a small increase in the voltage gap of 0.12 V after 170 cycles at 500 mA g^-1. Our work suggests a way to design metal-free catalysts with high activity that can be used to activate the performance of Li-CO₂ batteries.

Keywords: CO2 activation; Li-CO2 batteries; active site; graphene; nitrogen configuration.