Abstract
Li-CO2 battery provides a new strategy to simultaneously solve the problems of energy storage and greenhouse effect. However, the severe polarization of CO2 reduction and CO2 evolution reaction impede the practical application. Herein, anodic TiO2 nanotube arrays are first introduced as carbon-free and free-standing cathode for photo-assisted Li-CO2 battery, and the photo-assisted charge and discharge mechanism is first clarified from the perspective of photocatalysis. Mixed-phase TiO2 exhibits a long cycling life of 580h (52 cycles) at 0.025mA cm-2 and delivers a high discharge specific capacity of 3001 µAh cm-2 under UV illumination. The charge voltage dramatically reduces from 4.53 to 3.03V under UV illumination. The improvement of photo-assisted Li-CO2 battery performance relies on the synergistic effect of the hierarchical porous structure, strong UV absorption, efficient separation, and transfer of photo-generated electrons and holes at hetero-phase junction, and the facilitation of photo-generated electrons and holes on CO2 reduction and CO2 evolution reaction. This work can provide useful guidance for designing efficient photocathode for photo-assisted Li-CO2 battery and other metal-air batteries.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
