In situ growth of Ag aerogels mediating effective electrocatalytic CO2 reduction and Zn-CO2 batteries

•In-situ growth of Ag aerogels on carbon cloth was prepared as cathode electrode.•Its electrocatalytic CO2 performance was conducted in H-cell and Zn-CO2 batteries.•The FECO of 99.6%, and EECO of 59.85% were achieved at −1.0 V vs. RHE in H-cell.•It shows power density of 2.16 mW cm−2 and FECO of 95.3% in Zn-CO2 batteries.•CO2 fixing and energy storage and conversion were achieved simultaneously.