Pronounced improvement of supercapacitor capacitance by using redox active electrolyte of p-phenylenediamine

In this work, we present a simple but efficient template carbonization method to convert 1,4dichlorobenzene (p-DCB) into nanoporous carbon materials, using commercial available Mg(OH)(2) as template. The resulting carbon exhibits a large BET surface area of 1204.5 m(2) g(-1), and high pore volume of 2.03 cm(3) g(-1). More importantly, a novel redox active electrolyte of p-phenylenediamine (PPD) with quick reversible Faradaic process is introduced into the KOH electrolyte, forming PPD-KOH mixture electrolyte, to largely improve the electrochemical performance. As a result, the specific capacitance of the carbon sample obtained by adding 12 mmol PPD into 6 mol L-1 KOH can reach up to 501.4 F g(-1) at 3 A g(-1), which is almost 4.21 times than that of the pristine one (similar to 119.2 F g(-1)). Besides, it revealed that the PPD concentration in KOH electrolyte also plays a crucial role in determining the supercapacitor performance. The present redox active electrolyte of PPD is highly promising for producing superior electrochemical performance of supercapacitors. (C) 2015 Elsevier Ltd. All rights reserved.