A Novel Porous Activated Carbon Derived from Biomass for High Performance Supercapacitors

Abstract

Herein, to achieve waste utilization we report a novel porous activated carbon (KDTPAC) material prepared by using the old leaves of Kuding Tea tree already planted on a large scale. This carbon material gives a specific capacitance as high as 311 F/g at 1 A/g, a good rate capability with 69% of initial capacitance retention when the current density increases from 1 to 10 A/g, and an excellent cycling stability of 94% capacitance retention after 30000 charge-discharge cycles. The symmetric supercapacitor device assembled with this material can deliver an energy density of about 21 Wh/kg at 500 W/kg; moreover, displays a 76% of capacitance retention as the current density increases from 0.5 to 10 A/g, especially, still remains a 93% of initial capacity after 30000 charge-discharge cycles, exhibiting a superior rate capability and cycling stability. Such high performance is attributed to the superior physicochemical properties of this material.

Keywords: Electrochemical energy storage, ultra-high specific surface area, suitable aperture distribution, excellent cycling stability, high energy density