Booming Li–CO₂ Batteries by Optimizing Electronic Structural Configuration of Cathodic Catalysts

Li–CO₂ batteries (LCOBs) have garnered significant research interest in recent years owing to their exceptional theoretical energy density and potential carbon neutrality responses. However, challenges such as the stable thermodynamic properties of CO₂ and the nonconductivity of product Li₂CO₃ still hinder the practical application of LCOBs, resulting in high overpotential, poor energy conversion efficiency, and restricted capacity. It is believed that changing the electronic structure of the CO₂ cathodic catalyst to improve the inert interface of product nucleation and decomposition by manipulating the d-band center of transition metal-based materials could effectively solve the problem of sluggish kinetics of both CO₂ reduction reaction (CO₂RR) and CO₂ evolution reaction (CO₂ER). In this review, we summarize the ongoing progresses of representative cathodic catalysts for LCOBs from 2015 to 2024. We also evaluate the correlation between catalyst morphology and structure characteristics on the electrochemical activity of LCOBs. More importantly, we systematically discuss the d-band center regulation strategies that alter the electronic properties of catalysts, including heteroatom doping, defect/vacancy engineering, surface/interface engineering, crystalline engineering, heterojunction, atomic-sized catalysis, and strain modulation. We believe that this review would offer a profound understanding on the optimization of electronic configuration for CO₂ cathodic materials in LCOBs.