Potassium-ion aqueous supercapattery composed by solar carbon and nickel-zinc prussian blue analogue

•Relative abundant raw materials were employed to obtain double layer solar carbon and faradaic Ni-ZnHCF.•Solar carbon can reach more than 215 F g−1and exhibits excellent rate capability.•Mixed Ni-ZnHCF exhibited paramount performance compare to single PBAs.•Electrodes exhibit similar rate capability and energy storage capacity.•Assembled K-ion supercapattery shows excellent stability evaluated by GCD and EIS.