Light/Electricity Energy Conversion and Storage for a Hierarchical Porous In₂S₃@CNT/SS Cathode towards a Flexible Li‐CO₂ Battery

Abstract

Abstract A photoinduced flexible Li‐CO 2 battery with well‐designed, hierarchical porous, and free‐standing In 2 S 3 @CNT/SS (ICS) as a bifunctional photoelectrode to accelerate both the CO 2 reduction and evolution reactions (CDRR and CDER) is presented. The photoinduced Li‐CO 2 battery achieved a record‐high discharge voltage of 3.14 V, surpassing the thermodynamic limit of 2.80 V, and an ultra‐low charge voltage of 3.20 V, achieving a round trip efficiency of 98.1 %, which is the highest value ever reported (<80 %) so far. These excellent properties can be ascribed to the hierarchical porous and free‐standing structure of ICS, as well as the key role of photogenerated electrons and holes during discharging and charging processes. A mechanism is proposed for pre‐activating CO 2 by reducing In 3+ to In + under light illumination. The mechanism of the bifunctional light‐assisted process provides insight into photoinduced Li‐CO 2 batteries and contributes to resolving the major setbacks of the system.