Nitrogen-Rich Porous Carbon/NiMn Hybrids as Electrode Materials for High-Performance Supercapacitors

Abstract

The present work deals with the fabrication of four different electrode materials, that is, nitrogen-rich porous carbon (NRPC), NRPC/Mn, NRPC/Ni, and NRPC/NiMn, with a three-dimensional architecture following a simple strategic method. Polybenzoxazine is used as the precursor to prepare NRPC that serves both as a support and a electron collector. The inclusion of mono- and bimetallic transition compounds into the NRPC backbone, that is, NRPC/Mn, NRPC/Ni, and NRPC/NiMn, serves as the electrochemically active species. Several spectroscopic and microscopic methods are used to characterize the fabricated electrode materials. The prepared materials possess pore volume between 0.18 and 0.42 cm3/g. Scanning electron microscopy images of NRPC/NiMn show a 3D flowerlike structure. The formation of this 3D flower morphology depicts stable architecture showing improved electrochemical performance. Cyclic voltammetry, galvanostatic charge–discharge curves, and electrochemical impedance spectroscopy are used to evaluate the electrochemical performance of the prepared electrode materials. The electrochemical study reveals a high specific capacitance of 1825 F/g for NRPC/NiMn, with an efficiency of 78% maintained even after 2500 cycles.