Enhanced the Stability and Storage Capability of Sulfide-Based Material With the Incorporation of Carbon Nanotube for High-Performance Supercapattery Device

Supercapattery is a recently developed energy storage device that includes the properties of a supercapacitor and a rechargeable battery. A hydrothermal method is used to synthesize the sulfide-based materials. The structural morphology, elemental composition, and electrochemical properties are measured using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and potentiostat system. The specific capacitance is enhanced up to 1964.2 F/g by making the composite with carbon nanotubes (CNTs), which is higher than the reference sample (MnS). In the case of a real device, the obtained value of specific capacity in manganese sulfide/CNTs/activated carbon is 240 C/g which is much improved compared to the previously reported values. In a supercapattery device, an excellent energy density of 53.3 Wh/Kg and a high power density of 7995 W/kg are obtained. The stability of the device is measured up to 1000 cycles and achieved the specific capacity retention of 86% with columbic efficiency of 97%. Electrochemical impedance spectroscopy (EIS) and Brunauer–Emmett–Teller (Lee et al., 2012, Self-standing Positive Electrodes of Oxidized few-Walled Carbon Nanotubes for Light-Weight and High-Power Lithium Batteries,” Energy Environ. Sci., 5(1), pp. 5437–5444) measurements confirm the improvement in surface area and electrochemical properties. Our results show that a 50/50 weight ratio of manganese sulfide and CNTs are more suitable and provide opportunities to design high-performance energy storage devices.