Engineering the Active Sites of Graphene Catalyst: From CO<sub>2</sub> Activation to Activate Li-CO<sub>2</sub> Batteries.

Chen, Biao; Wang, Dashuai; Zhang, Biao; Zhong, Xiongwei; Liu, Yingqi; Sheng, Jinzhi; Zhang, Qi; Zou, Xiaolong et al. · ACS Nano · 2021

basic_science · Level V

Where this comes from

Abstract

As one of the CO<sub>2</sub> capture and utilization technologies, Li-CO<sub>2</sub> 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 Li<sub>2</sub>CO<sub>3</sub> formation and decomposition remains challenging. Here, guided by theoretical calculations, CO<sub>2</sub> 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 CO<sub>2</sub> reduction and evolution reactions, thus activating the reversible conversion of Li<sub>2</sub>CO<sub>3</sub> formation and decomposition. As a result, the designed cathode has a low voltage gap of 2.13 V at 1200 mA g<sup>-1</sup> and long-life cycling stability with a small increase in the voltage gap of 0.12 V after 170 cycles at 500 mA g<sup>-1</sup>. Our work suggests a way to design metal-free catalysts with high activity that can be used to activate the performance of Li-CO<sub>2</sub> batteries.