Method for preparing active carbon for super-capacitor from potassium humate in one-step carbonization way

Abstract

The invention provides a method for preparing active carbon for a super-capacitor from potassium humate in a one-step carbonization way. The method comprises the following steps of placing the potassium humate in a reaction kettle, heating the reaction kettle to 180 DEG C at a heating rate of 5 to 20 DEG C per minute under the protection of nitrogen, dehydrating for 0.5h at the constant temperature, then heating the reaction kettle to 600 to 900 DEG C, carbonizing the potassium humate for 0.5h to 3h at the constant temperature, naturally cooling to the room temperature under the protection of nitrogen after the carbonization is ended, sequentially acid-dipping and washing a carbonized product till the product is neutral, and filtering and drying the neutral product to obtain the active carbon for the super-capacitor. The active carbon for the super-capacitor has medium specific surface area (ranging from 80 to 500 m<2> / g), high forming density (ranging from 0.76 to 0.93 g / cm<3>) and high volumetric specific capacitance which can reach 100 to 150 F / cm<3> when the active carbon is in 3mol / L KOH electrolyte, and the active carbon is particularly applicable to the high-energy super-capacitor with limited space.

Description

technical field

[0001] The invention relates to a method for preparing activated carbon, in particular to a method for preparing activated carbon for supercapacitors by one-step carbonization of potassium humate. technical background

[0002] Supercapacitor is a new type of energy storage device, which has the advantages of high power density of ordinary capacitors and high energy density of secondary batteries, fast charging speed, long cycle life, safety and pollution-free. Supercapacitors are mainly composed of electrode materials, electrolytes, current collectors, and diaphragms. Among them, electrode materials are the key factors that determine the performance of supercapacitors. Therefore, the development of electrode materials with excellent performance has attracted extensive attention. Among many electrode materials (such as activated carbon, carbon aerogel, porous carbon such as carbon nanotubes, metal oxides and conductive polymers), activated carbon is due to its...