Boosting Energy Efficiency and Stability of Li–CO<sub>2</sub> Batteries via Synergy between Ru Atom Clusters and Single‐Atom Ru–N<sub>4</sub> sites in the Electrocatalyst Cathode
Jiangfeng Lin, Jingnan Ding, Jingnan Ding, Haozhi Wang, Xinyi Yang, Xuerong Zheng, Zechuan Huang, Wanqing Song, Jia Ding, Jia Ding, Xiaopeng Han, Wenbin Hu
Abstract
Abstract The Li–CO 2 battery is a novel strategy for CO 2 capture and energy‐storage applications. However, the sluggish CO 2 reduction and evolution reactions cause large overpotential and poor cycling performance. Herein, a new catalyst containing well‐defined ruthenium (Ru) atomic clusters (Ru AC ) and single‐atom Ru–N 4 (Ru SA ) composite sites on carbon nanobox substrate (Ru AC+SA @NCB) (NCB = nitrogen‐doped carbon nanobox) is fabricated by utilizing the different complexation effects between the Ru cation and the amine group (NH 2 ) on carbon quantum dots or nitrogen moieties on NCB. Systematic experimental and theoretical investigations demonstrate the vital role of electronic synergy between Ru AC and Ru–N 4 in improving the electrocatalytic activity toward the CO 2 evolution reaction (CO 2 ER) and CO 2 reduction reaction (CO 2 RR). The electronic properties of the Ru–N 4 sites are essentially modulated by the adjacent Ru AC species, which optimizes the interactions with key reaction intermediates thereby reducing the energy barriers in the rate‐determining steps of the CO 2 RR and CO 2 ER. Remarkably, the Ru AC+SA @NCB‐based cell displays unprecedented overpotentials as low as 1.65 and 1.86 V at ultrahigh rates of 1 and 2 A g −1 , and twofold cycling lifespan than the baselines. The findings provide a novel strategy to construct catalysts with composite active sites comprising multiple atom assemblies for high‐performance metal–CO 2 batteries.