J. Mater. Sci. Technol. ›› 2021, Vol. 95: 105-113.DOI: 10.1016/j.jmst.2021.03.066

• Research Article • Previous Articles     Next Articles

Biowaste derived porous carbon sponge for high performance supercapacitors

Wenbin Zhanga, Bei Liua, Mei Yanga,d,**(), Yijiang Liua, Huaming Lia,b, Pingle Liuc,*()   

  1. aCollege of Chemistry, Xiangtan University, Xiangtan 411105, China
    bKey Laboratory of Polymeric Materials & Application Technology of Hunan Province, Key Laboratory of Advanced Functional Polymeric Materials of College of Hunan Province, and Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, China
    cCollege of Chemical Engineering, Xiangtan University, Xiangtan 411105, China
    dPostdoctoral Station of Chemical Engineering and Technology, Xiangtan University, Xiangtan 411105, China
  • Received:2020-11-30 Revised:2021-03-24 Accepted:2021-03-25 Published:2021-12-30 Online:2021-05-25
  • Contact: Mei Yang,Pingle Liu
  • About author:* E-mail addresses: liupingle@xtu.edu.cn (P. Liu).
    ** College of Chemistry, Xiangtan University, Xiangtan 411105, China. E-mail addresses: yangmei@xtu.edu.cn (M. Yang),

Abstract:

Here, an agricultural waste (the stem pith of helianthus annuus, SPHA) is firstly used as the precursor for preparing three-dimensional (3D) porous carbon sponge (PCS). The as-prepared 3D PCS (SPHA-700) possesses unique sponge-like structure, large specific surface area (SSA) and high nitrogen doping level (4.52 at.%), which benefit the enhancement of conductivity (5.8 S cm-1) and wettability. As a binder-free electrode for solid-state symmetric supercapacitor, SPHA-700 delivers a relatively high specific capacitance of 137.1 F g-1 at 0.5 A g-1. Moreover, activated SPHA-700 (SPHA-ac-700-2) displays an even higher specific capacitance (403.6 F g-1 at 0.5 A g-1) in 6.0 M KOH electrolyte. The SPHA-ac-700-2-based symmetrical supercapacitor can offer high specific capacitance (271 F g-1 at 1 A g-1) and good rate capability (82.1% of capacitance retention at 1-80 A g-1) in 6.0 M KOH electrolyte, together with high energy density (23.3 Wh kg-1 at 450 W kg-1) in 1.0 M Na2SO4 electrolyte. Such excellent performance of SPHA-ac-700-2 is believed to have originated from the crushed sponge-like structure, O/N-co-doping (10.6 at.% O and 3.3 at.% N), high SSA, large total pore volume, and hierarchical pore structure.

Key words: Agricultural waste, Carbon sponge, Three-dimension, Supercapacitors