Activated hierarchical porous carbon as electrode membrane accommodated with triblock copolymer for supercapacitors

• Published in: Journal of membrane science 2016-09, Vol.514, p.366-375
• Main Authors: Ran, Fen, Shen, Kuiwen, Tan, Yongtao, Peng, Bowu, Chen, Shaohua, Zhang, Weijie, Niu, Xiaoqin, Kong, Lingbin, Kang, Long
• Format: Article
• Language: English
• Subjects: Activated carbon; Activated hierarchical porous carbon; Block copolymers; Capacitance; Carbon; Current density; Electrodes; Membranes; Phase inversion; Supercapacitors; Triblock polymer
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2016.05.011

Homopolymer PAN and triblock copolymer PAN-b-PMMA-b-PAN synthesized by RAFT polymerization were used to fabricate activated hierarchical porous carbon membranes by combining phase inversion, carbonization, and HNO3 activation method; during the preparation process, a lot of micro- and meso-pores generated because of phase separation of PAN and microphase separation of PAN-b-PMMA-b-PAN. The hierarchical porous structure shortened ions transport paths and facilitated the rapid migration of electrolyte ions. When the polymer membrane was prepared by the casting solution with 5wt% of PAN-b-PMMA-b-PAN and the electrochemical performance was tested at the current densities from 0.5 to 5Ag−1, a high-end specific capacitance of 297.0Fg−1 and a capacitance retention of 75% were obtained in three-electrode configuration; this specific capacitance remained above 90% of initial value after 2000 cycles at 2Ag−1 in 6M KOH aqueous solution. Moreover, symmetric supercapacitors assembled with the prepared materials achieved high energy density (15.8WhKg−1) and power density (4000WKg−1) in 1M Na2SO4 solution. The unique features and structures endowed the electrode membrane with good capacitive performance in both three-electrode and two-electrode configuration, which can be used as electrode membranes for high-performance energy storage devices and other applications. [Display omitted] •An electrode membrane of activated hierarchical porous carbon was fabricated•Micro- and meso-pores generated due to the phase and microphase separation.•Effects of copolymer concentration on structure and performance were studied•High electrochemical performance for supercapacitor was obtained.