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

Abstract

In this work, we present a simple but efficient template carbonization method to convert 1,4-dichlorobenzene (p-DCB) into nanoporous carbon materials, using commercial available Mg(OH)2 as template. The resulting carbon exhibits a large BET surface area of 1204.5m2g−1, and high pore volume of 2.03cm3g−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 6molL−1 KOH can reach up to 501.4Fg−1 at 3Ag−1, which is almost 4.21 times than that of the pristine one (∼119.2Fg−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.