Solar-driven, CO2-fed rechargeable molten salt carbon battery for rational carbon capture, electricity and fuel production

Herein, a solar-driven, CO2-fed rechargeable molten salt carbon battery is reported, which has the characteristics of capacity-tunable and noble metal catalyst-free, and continuously captures CO2 and converts it into fuel (CO). The battery uses mixed molten carbonate as the electrolyte, which has excellent reversible electrode kinetics and superior ionic conductivity, providing the rechargeable molten salt battery excellent storage capacity and power capability. The battery is capable of continuously absorbing CO2 from the atmosphere and converting it into carbon and carbon monoxide when it is charged. The carbon accumulates at the cathode and is used to discharge, thus producing carbon monoxide, constituting a battery capable of continuously converting carbon dioxide into carbon monoxide and storing electrical energy. The battery is perfectly matched to solar thermal and solar electricity and can be used as a novel method of storing solar energy. This paper investigates the battery performance under four electrolyte conditions. The results show that the battery has the most superior discharge performance when using a Li-Na-K-Cs-Li2O mixed electrolyte, maintaining ultra-high faradaic efficiency (100%) for 20 cycles. This work provides a new horizon for CO2 conversion and solar energy utilization.