Boosting Cycling Stability and Rate Capability of Li-CO2 Batteries via Synergistic Photoelectric Effect and Plasmonic Interaction.

Abstract

Sluggish CO2 reduction/evolution kinetics at cathodes seriously impede the realistic applications of Li-CO2 batteries. Herein, synergistic photoelectric effect and plasmonic interaction are introduced to accelerate CO2 reduction/evolution reactions by designing a silver nanoparticle-decorated titanium dioxide nanotube array cathode. The incident light excites energetic photoelectrons/holes in titanium dioxide to overcome reaction barriers, and induces the intensified electric field around silver nanoparticles to enable effective separation/transfer of photogenerated carriers and a thermodynamically favorable reaction pathway. The resulting Li-CO2 battery demonstrates ultra-low charge voltage of 2.86 V at 0.10 mA cm-2 , good cycling stability with 86.9 % round-trip efficiency after 100 cycles, and high rate capability at 2.0 mA cm-2 . This work offers guidance on rational cathode design for advanced Li-CO2 batteries and beyond.