Photoelectrocatalyst in Lithium–Carbon Dioxide Batteries: A Systematic Review and Mechanistic Analysis

Lithium–carbon dioxide batteries have significant potential in energy storage due to their high energy density (1876 Wh kg⁻¹) and ability to recycle CO₂. However, their practical application is significantly hindered by the sluggish cathodic kinetics. While electrocatalysts have been extensively studied to improve reaction kinetics, they remain incapable of overcoming the fundamental thermodynamic bottlenecks of these reactions. To address this limitation, photoresponsive electrocatalysts have emerged as an innovative solution. By introducing light fields, these catalysts utilize photoelectric coupling mechanism to surpass thermodynamic limits, reduce energy loss, and enhance overall battery performance. This review systematically discusses the design strategies of photoresponsive electrocatalysts, including plasmonic resonance effects, heterojunction construction, combining photosensitive materials with conductive substrates, and nanostructure optimization. These approaches have demonstrated remarkable advantages in enhancing light absorption, promoting photogenerated carrier separation, and improving catalytic activity. The mechanisms, methods for performance characterization, and specific roles of these catalysts in facilitating CO₂ reduction and Li₂CO₃ decomposition are comprehensively explored. In response to challenges such as electrolyte decomposition in practical applications, this review also summarizes research directions such as the development of solid-state batteries, aiming to provide reference for the design and development of catalysts in light-assisted lithium carbon dioxide batteries.