Dual Catalytic Sites of Alloying Effect Bloom CO2 Catalytic Conversion for Highly Stable Li–CO2 Battery

Abstract

Owing to the ingenious utilization of CO2 conversion electrochemistry, rechargeable Li–CO2 batteries, have attracted more and more attention. However, the large potential polarization resulting from the sluggish CO2 reduction/evolution electrochemistry degrades energy efficiency and cycling performance. One possibility to break the kinetic bottlenecks of -Li–CO2 batteries is to design high-efficiency catalysts with flexible geometric and electronic structures. Herein, an efficient synergistic catalyst with unique alloyed dual catalytic sites composed of uniformly ultrafine Ir–Ru alloyed nanoparticles modified nitrogen-doped carbon nanotube composite (denoted as IrRu/N-CNT) is synthesized. Combining the synergistic effect between the remarkably enhanced catalytic activity of Ir–Ru dual catalytic sites, the Li–CO2 battery delivers a high discharge capacity of 6228 mAh g−1 and outstanding stability over 7660 h. Density functional theory (DFT) calculation results uncover that the excellent electrochemical performance is ascribed to the novel dual catalytic sites on the surface of IrRu nanoalloys, which effectively modify its electronic structures and shorten the electron transfer pathway, leading to the deposition of film-like Li2CO3 products. This study highlights the novel view of building a dual catalytic site and provides some new insights for understanding the catalytic mechanism of an alloying-type bifunctional catalyst toward realizing high-performance Li–CO2 batteries.