Electropolymerization and energy storage of poly[Ni(salphen)]/MWCNT composite materials for supercapacitors

Ni(salphen), a Schiff base ligand compound, was synthesized and electropolymerized on multiwalled carbon nanotube (MWCNT) electrodes in an acetonitrile solution via the pulse potentiostatic method and then applied as a supercapacitor electrode material. The polymerization mode was investigated through methyl replacement in the para-position of phenyl rings in the Ni(salphen) monomer, and it was found that the Ni(salphen) monomers would polymerize by the generation of CC bonds between the phenyl rings in the para-position of the phenol moieties. The optimum condition for polymerization was evaluated, and when the polymerization time was 8 min, poly[Ni(salphen)] exhibited a specific capacitance up to 200 F g−1 at a current density of 0.1 mA cm−2, and the capacitance remains at 164 F g−1 at 20 mA cm−2. The energy density of the poly[Ni(salphen)] electrode reached 40 Wh kg−1 at 0.1 mA cm−2, about eight times greater than for a pure MWCNT electrode. Electrochemical performances were investigated, and the composites showed good redox property and ion transfer capability. This work showed that Ni(salphen) may be an attractive material in supercapacitors© 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44464.