The Synthesis and Characterization of Bioactive Carbon Material Supercapacitor Loaded with Nickel Hydroxide

Abstract

Supercapacitor is an environmentally friendly energy storage device, which fills the gap between traditional capacitors and batteries, and its energy density and power density are higher than the battery [1]. Moreover, the supercapacitor has the characteristics of high charging and discharging efficiency and long cycle life. This makes it used in the electric vehicles, high powered weapons, standby power in electronic equipment, flash of industrial equipment and ignition device [2]. So it has great significance for the basic research, the development of electronic industry and the electric vehicle to carry out the supercapacitor electrode materials [3]. Here, we firstly prepared the activated carbon materials by carbonizing, activating the biological material, then prepared the nickel hydroxide/activated carbon composites by direct precipitation method, and studied the electrochemical properties of composite materials with different nickel hydroxide (Ni(OH)2) contents (the mass fraction). The results of cyclic voltammetry and constant current charge-discharge are that a small amount of Ni(OH)2 are mixed in the carbon surface and pores, the composite material has a good specific capacitance, stability, charging and discharging performance compared with the activated carbon. When the mass fraction of Ni(OH)2 is 12%, the supercapacitor exhibits the excellent electrochemical properties, its capacitance is up to 400.78F/g which improved 75.21% compared with the activated carbon’s capacitance (228.74F/g). 6mol/L potassium hydroxide (KOH) is used as an electrolyte, the capacitance is only reduced to 94.42% after conducting 1000 times cycle life tests. This means that the supercapacitor shows a good stability.