Abstract
Composite electrodes for supercapacitors have been obtained, consisting of a matrix of highly dispersed carbon materials: microcrystalline graphite and multi-walled carbon nanotubes, also a filler of nanoparticles of nickel hydroxide. Β-Co (OH) 2 and β-Ni (OH) 2 nanopowders were obtained by chemical deposition from solution. To create the electrodes, a polyvinylidene fluoride polymer in the form of a powder was used as a bonding material. The main technological stages of the manufacture of electrodes were determined, the parameters of the obtained structures were measured by the method of cyclic voltammetry and galvanostatic charge-discharge. For the manufacture of carbon electrodes, the optimal ratios of highly dispersed carbon materials, a binder polymer and a solvent have been determined to create mechanically strong layers with high conductivity and capacity. The technique of creating capacitor structures and measuring the capacitance of the obtained electrochemical capacitors has been worked out. Capacitors made of highly dispersed carbon materials showed typical rectangular curves of cyclic voltammetry and a linear decay-rise of the galvanostatic charge-discharge dependences. Typical values of specific capacity ~ 50 F / g were obtained. Composite electrodes made of nickel hydroxide nanoparticles in a carbon matrix demonstrated an increase in capacitance to ~ 180 F / g. It is shown that composite electrodes are promising for creating capacitors with a high specific capacity.