A solid-state semiconductor battery with silica-coated TiO2 core–shell energy storage nanoparticles for rechargeable device application

A solid-state semiconductor battery with the n-type WO3/silica-coated TiO2 core–shell nanoparticles/p-type NiO laminated structure for the rechargeable device has been developed. The electricity storage layer comprises poly-acrylonitrile mixed with core–shell nanoparticles containing n-type TiO2 particles coated with an insulating SiO2 shell. The average diameter size of nanoparticles was determined from 20 to 50 nm by a high-resolution transmission electron microscope and the relative atomic weight percentage of the Si on the coated TiO2 nanoparticles had been qualitatively determined by the energy dispersive spectrometer. The silica-coated TiO2 nanoparticles in the composite were assigned to the mixed phases of Anatase and Rutile by XRD analysis. Furthermore, photoluminescence analysis has verified the energy levels present in the bandgap of the silica-coated TiO2 core–shell nanoparticles. The device exhibits a constant-current discharge capacity of 0.16 mA h at a discharge voltage of 2.46 V. The energy density of the charging layer has been estimated to 12.3 Wh/kg. Finally, a mechanism of the solid-state semiconductor battery has also been proposed.