A lithium-ion supercapacitor with a positive electrode based on a highly porous carbon material modified with an electronically conducting polymeric nickel Schiff base complex has been developed for the first time. The electrochemical capacity of the obtained device was over 40% higher than the capacitance of the cell with a non-modified positive electrode without compromising other performance parameters (working voltage, resistance, number of charge-discharge cycles).

Complexes of metals with Schiff bases are considered as promising materials for creating energy storage and photovoltaic devices. In this work, the semiconducting properties of a polymer nickel film with a salen-type ligand (poly-Ni(CH3O-Salen)) were studied by spectrophotometric and Faraday impedance spectroscopy. The Mott-Schottky analysis showed that the polymer film is a semiconducting material with a fairly narrow band gap, high charge carrier density and p-type conductivity. Using the method of Faraday impedance spectroscopy, the limiting stage of the oxygen photoelectroreduction reaction, the process of charge transfer from the film to molecular oxygen, has been established.

This work describes the method of preparation of composite lithium-ion battery cathodes that allows total replacement of conventional polymer binders and electroconductive carbon black additives with redox-active conductive polymeric nickel complexes of salen-type Schiff base ligands in the electrode layer. The structure and electrochemical behavior of the electrodes prepared by this method have been investigated. Polymeric metal complexes have been shown to successfully perform the functions of binding and conductive components and also reversibly store charge in the lithium iron phosphate cathodes, which could result in the improvement of the specific capacity of the cathode layer, as compared with the conventional electrodes.

Effect of the modification of a porous carbon material used in supercapacitors by a polymeric complex of cobalt with a Salen-type Schiff base ligand on the material capacity have been studied. Conjunction of multielectron redox processes in the polymer with the proposed effective modification technology makes it possible to increase the electrode capacity by 2.4 times in comparison with unmodified carbon electrodes. Specific capacity of the polymer poly-[Co(CH3OSaltmen)] at a polymer deposition density of 1.3 mg•cm-2 was 170 mA•h•g-1.