Engineering the Active Sites of Graphene Catalyst: From CO<sub>2</sub> Activation to Activate Li-CO<sub>2</sub> Batteries
Biao Chen, Dashuai Wang, Biao Zhang, Xiongwei Zhong, Yingqi Liu, Jinzhi Sheng, Qi Zhang, Xiaolong Zou, Guangmin Zhou, Hui–Ming Cheng
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.