Enhancement in performance of negative electrode of supercapacitor based on nitrogen doped porous carbon spheres

It is a great challenge to prepare high capacitance negative electrodes for high energy density supercapacitor devices. In this work, nitrogen doped carbon spheres in-situ grown on Ni foam (N doped CS/NF) are prepared as a binder-free negative electrode for supercapacitors. Due to the formation of hierarchical porous structure and N contents after nitrogen-doping, the specific area and electrochemical active sites on the surface of the electrode are effectively increased. Therefore, the specific capacitance of N doped CS/NF electrode is remarkably improved compared to pristine carbon spheres electrode. The synthesized N doped CS/NF negative electrode provides a high areal specific capacitance (C-A) of 5.75 F cm(-2) at 5 mA cm(-2) and mass specific capacitance (C-m) of 287.5 F g(-1) at 0.25 A g(-1). Furthermore, the electrode shows an excellent cycle stability of 115.6% after 10000 cycles at 100 mA cm(-2). This study proposes a synergistic approach to enhance the electrochemical performance of supercapacitor's negative electrode. (C) 2019 Elsevier B.V. All rights reserved.