Cornhusk mesoporous activated carbon electrodes and seawater electrolyte: The sustainable sources for assembling retainable supercapacitor module

Renewable and sustainable energy sources are essential for modern society especially for the energy storage device owing to the usage of nonrenewable resources and considering the cost of the raw materials. In this work, we design a supercapacitor utilizing activated carbon from the agricultural waste cornhusk (CHAC) as an electrode material and seawater as the electrolyte. Moreover, the supercapacitor is assembled and test employing different substrates such as stainless steel, nickel foam, carbon cloth and titanium. Among them, the Ti-based electrode exhibits comparable electrochemical performances and high stability in the seawater electrolyte than the stainless steel (SS)-based and other electrodes. The supercapacitor with CHAC deposit on Ti substrate shows considerable specific capacitance value (130 F g⁻¹), better energy density (7.74 W h kg⁻¹) and stability ~98% for 10000 cycles in an optimize electrolyte concentration (seawater). Furthermore, a laboratory-scale portable supercapacitor module demonstrates considerable electrochemical performances and also the retainability of the device can maintain by recharging fresh electrolyte after several charging/discharging cycles.