context: Fig. 1a schematically shows the composition of the light-assisted Li–CO2 battery, which consisted of a Li anode, a non-aqueous electrolyte, a separator, and a cathode with the photo-electro-catalyst. Upon discharging under illumination (Fig. 1b), the photocatalyst is excited to generate holes and electrons after absorbing photons. Since the conduction band potential (VCB) of the photocatalyst is more negative than the standard redox potential of 2.8 V, photoexcited electrons could reduce CO2 by a photocatalytic reaction. Notably, the solar light provides significant energy for CO2 reduction in sharp contrast with the conventional Li–CO2 battery, in which the carbon dioxide reduction reaction (CO2RR) process is driven by the electrocatalytic reaction. Meanwhile, photoexcited holes capture the electrons from the Li anode through the external circuit due to the more positive valence band potential (VVB) than 2.8 V, ensuring the continuous supply of photoexcited electrons for the CO2RR process. During the charging process (Fig. 1c), the inverse reaction 4Li + 3CO2 → 2Li2CO3 + C is promoted by the photoexcited holes on the cathode on account of the positive VB position compared with 2.8 V. Simultaneously, the photoexcited electrons transfer to the anode through the external circuit to reduce Li+ to Li metal. In this photoassisted charging process, the photovoltage generated on the photo-catalyst is utilized to compensate the charging potential of the Li–CO2 battery.