Effect of TiO2 grain size on performance of Ba0.5Sr0.5TiO3 based capacitors for energy storage application

Abstract Performance of energy storage devices, particularly metal‐insulator‐metal capacitors are evaluated mainly by leakage current and specific capacitance. The insulator material BaSrTiO shows high specific capacitance owing to its high relative permittivity. In this work, BaSrTiO nanopowder is synthesized using commercially available TiO nanopowder (ACS reagent grade) as well as using synthesized TiO nanopowder from Ti isopropoxide. The crystallinity and grain sizes of commercially available and synthesized TiO nanopowder differ. The effects of crystallinity and grain size of TiO nanopowder on specific capacitance and leakage current density of BaSrTiO ceramic based metal‐insulator‐metal capacitors are investigated in this paper. An 88 % reduction in grain size is achieved in TiO nanopowder synthesized from Ti isopropoxide compared to commercially available TiO nanopowder. A 45 % enhancement in specific capacitance and 57 % enhancement in leakage current are achieved in BaSrTiO ceramic based metal‐insulator‐metal capacitor synthesized using TiO nanopowder with lower grain size. The lower leakage current of metal‐insulator‐metal capacitor with BaSrTiO ceramic of low grain size is investigated with its structure using X‐ray powder diffraction pattern analysis as well. The BaSrTiO ceramics synthesized using TiO nanopowder with lower grain size is a suitable candidate for insulator material in metal‐insulator‐metal capacitors for energy storage application.