J. Mater. Sci. Technol. ›› 2018, Vol. 34 ›› Issue (11): 2189-2196.DOI: 10.1016/j.jmst.2018.03.010

• Orginal Article • Previous Articles     Next Articles

Synthesis of porous carbon spheres derived from lignin through a facile method for high performance supercapacitors

Yuemei Chena, Guoxiong Zhanga, Jingyuan Zhanga, Haibo Guoa, Xin Fengb, Yigang Chena, *()   

  1. a Department of Electronic Information Materials, School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China
    b Nano-Science & Technology Research Center, Shanghai University, Shanghai, 200444, China;
  • Received:2017-07-30 Revised:2017-11-04 Accepted:2017-12-30 Online:2018-11-20 Published:2018-11-26

Abstract:

Porous carbon spheres (PCS) derived from lignin have been prepared through a facile method and fabricated as electrodes for electric double-layer capacitors. Spherical shaped mixtures of lignosulfonate and crystalized KOH are formed by spray drying of a solution of lignosulfonate and KOH. Activation by KOH is performed at high temperatures along with lignosulfonate carbonization. With an appropriate pore structure, the obtained PCS have a specific surface area of 1372.87 m2 g-1 and show a capacitance of 340 F g-1 in 3 M KOH at a current density of 0.5 A g-1. Moreover, a symmetric supercapacitor fabricated using the PCS as electrodes show a maximum capacitance of 68.5 F g-1, and an energy density of 9.7 W h kg-1 at a power density of 250 W kg-1. The capacity retention is more than 94.5% after 5000 galvanostatic charge-discharge cycles. The excellent characteristics seem to be ascribed to the pore structures of PCS that have a large specific surface area and a low electrical resistance.

Key words: Porous carbon spheres, Supercapacitors, Spray drying, KOH activation