Superior performance of cobalt oxide/carbon composite for solid-state supercapattery devices

Asymmetric devices are fabricated by cramming the active material Co3O4/C composite (positive electrode) with activated carbon (negative electrode). Devices are examined under aqueous and gelled electrolyte. The theoretical model is adopted to study the charge storage mechanism in two devices. It has been observed that the capacitive and diffusion-controlled contribution of electrode material is affected by the phase change of electrolyte. Diffusive contribution is prominent in case of 1 M KOH aqueous electrolyte while more capacitive contribution has been noticed in PVA-KOH-C gelled electrolyte. By changing the phase of electrolyte, the potential window is enhanced which upsurges the energy density of device. For commercial applications, solid state device exhibits more energy storage and have high safety standards than aqueous electrolyte-based devices.

Automated summary

The study found that the contribution of electrode material in terms of capacitance and diffusion control is affected by the phase change of electrolyte. Changing the phase of electrolyte enhances the potential window and increases the energy density of the device. Solid state devices exhibit higher energy storage and safety standards in commercial applications compared to devices based on aqueous electrolytes.