Structural and electrochemical properties of undoped and In3+-doped multi-phase zinc- antimony oxide for a high-performance pseudocapacitor

•Undoped/In3+-doped ZnSb2O4 was synthesized using the wet chemical solution.•In3+-doped ZnSb2O4 was predicted a weak p-type semiconductor with the lower-than-band gap optical absorption.•The Cs of 470 mAh g−1 was obtained for the In3+/ZAO electrode at the scan rate of 10 mV s−1.•In3+ doping leads increasing energy density and power density ~ 1.4 fold.•The 81% capacitance retention and 93% coulombic efficiency after 150 cycles are achieved. Pseudocapacitive charge storage devices based on undoped and In3+-doped multi-phase zinc- antimony oxide (ZAO) with high potential insertion/removal processes of disulfide ions the electrodes were performed. The thin film morphologies related to a more regular grain shape, leading to enhanced surface mobility and nucleation density. The sizes of the nanoparticles (NPs) for undoped and In3+-doped ZAO were uniformly distributed between ~ 100 − 500 nm. Based on electronic structure calculations, the In3+-doped ZnSb2O4 behaves as a weak p-type semiconductor with a lower-than-band gap optical absorption and has greater charge storage performance diffused into the surface of electrode. This results in it obtaining a lower barrier layer and charge transfer resistance at the interface. In3+ doping in the ZAO electrode was driven in increments of energy density (77.34 Wh kg−1), power density (13.92 kW kg−1), specific capacitance (470 mAh g−1@10 mV s−1), and average capacitance retention (~87%). It is noted that the synthesized material in the present study and the importance of In3+ doping should be further considered for high-performance pseudocapacitor applications. [Display omitted]