High temperature-functioning ceramic-based ionic liquid electrolyte engraved planar HAp/PVP/MnO2@MnCO3 supercapacitors on carbon cloth

Abstract

In this study, we prepared ceramic-based hydroxyapatite (HAp)/polyvinylpyrrolidone (PVP)/MnO₂@MnCO₃ composites for high temperature-operable electrolyte-engraved planar supercapacitors. The electrode material was prepared to deposit a composite coating of HAp, PVP, and MnO₂@MCO₃ on carbon cloth via a one-step hydrothermal technique. The chemical compositions, crystallinity, morphologies, and thermal stability of the resulting composites were investigated by carrying out Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy, and thermogravimetric analyses. The XPS profiles of the composites exhibited Mn 2p_1/2 (653.6 eV), Mn 2p_3/2 (642.2 eV), N 1s (401.3 eV), and C 1s (285.1 eV) peaks. The planar supercapacitor showed an areal capacitance of ∼84 mF cm⁻² and a gravimetric specific capacitance of 409.5 F g⁻¹ with energy density of 56.9 W h kg⁻¹. The supercapacitor exhibited a specific capacitance of 126 F g⁻¹ up to 400 °C. The supercapacitor showed capacity retention of 90% after 100 000 charge–discharge cycles. The supercapacitor prepared in this study was found to be suitable for application in smart electronic devices operating at high temperatures.