As the demand for new power increases, such as the next generation all-electric cars, many composites are promoted as new potential materials and exhibit good electrochemical performance. Metal-containing polymer chemistry is a growing field and the development of polymer-modified electrodes is of great interest to researchers not only because Schiff base complexes polymers can be conveniently polymerized by direct electrolysis, but also because of potential applications in electrocatalysts, chemical sensors and electrochromic display.

Researchers with University of Science and Technology Beijing, Tsinghua University and Institute of Process Engineering (IPE) conducted experiments to study the electropolymerization and electrochemical performance of salen-type redox polymer on different carbon supports for supercapacitors.

In their work, Ni(salen) was used for electropolymerization to form conductive polymer acting as an electroactive material for supercapacitor by depositing onto the electrode surface with activated carbon (AC), mesoporous carbon (MC) and multi-walled carbon nanotube (MWCNT) as a support, respectively. The polymer film produced by Ni[salen]-type monomers were combined with the support materials to improve the performance of electric double layer capacitors (EDLC). Different properties of microstructure, size distribution among the three kinds of carbon supports were addressed, and the resulting variations in electrochemical response of the as-prepared poly[Ni(salen)] were demonstrated and discussed through electrochemical measurement method.

The electropolymerization was conducted in a closed three-electrode compartment cell. The electrodeposition of Ni(salen) on the resulting electrode (1 cm×1 cm) was performed in AN solution which containing 1.0 mmol L？1 Ni(salen) complex monomer and 0.1 mol L？1 TBAP by potential dynamic electrode position. The poly[Ni(salen)] electrodes were then washed and tested in a monomer-free solution in acetonitrile. Cyclic voltammetry (CV), chronoamperometry (CA), galvanostatic charge/discharge test, and electrochemical impedance spectroscopy (EIS) were measured with the same counter and reference electrodes.

Poly[Ni(salen)] was synthesized onto different carbon supports including AC, MC and MWCNT via potential dynamic polymerization and the effects of the substrates on electrochemical performance of conducting redox polymer were analyzed. Results showed the important role of the supports, and Poly[Ni(salen)] with different supports had different initial growth rates and exhibited various ionic diffusion abilities. Poly[Ni(salen)] grown on the MWCNT support possessed a higher charge storage ability, and the capacitance of the as-prepared poly[Ni(salen)] with MWCNT as a support increased to 3.79 times as the performance of raw MWCNT electrode.

While how to union the two materials effectively, fully display respective merits and their conformity superiority have not been discussed yet. More information about the paper please see Electrochimica Acta.