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

作者:Ran, Fen*; Shen, Kuiwen; Tan, Yongtao; Peng, Bowu; Chen, Shaohua*; Zhang, Weijie; Niu, Xiaoqin*; Kong, Lingbin; Kang, Long
来源:Journal of Membrane Science, 2016, 514: 366-375.
DOI:10.1016/j.memsci.2016.05.011

摘要

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 mesopores 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 5 wt% of PAN-b-PMMA-b-PAN and the electrochemical performance was tested at the current densities from 0.5 to 5 A g(-1), a high-end specific capacitance of 297.0 F g(-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 2 A g(-1) in 6 M KOH aqueous solution. Moreover, symmetric supercapacitors assembled with the prepared materials achieved high energy density (15.8 Wh Kg(-1)) and power density (4000 W Kg(-1)) in 1 M 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.