O.V. Volkova, V.V. Zakharov, S.V. Pershina, B.D. Antonov, А.Е. Vakhromeeva.
ABSTRACT
Discharge characteristics of the heat activated battery with NiCl2-WO3 mixtures as a cathode material has been investigated. Using of mixtures instead of pure nickel chloride allows are decreasing of the discharge temperature of electrochemical cell without loss of power characteristics was founded. The maximum capacity of the discharge plateau is 0.35 A×h/g. The optimal composition of the cathode mixture contains 10 wt % WO3. Composition and morphology of reduction products of the cathode materials have been determined. It was found that during the discharge of electrochemical cell, the initial nickel chloride and tungsten oxide are reduced to metals. The reduction process is accompanied by diffusion of lithium halides from the separator into the cathode space. Reduced metals (Ni, W) form a network of branched dendrites covered with a salt film based on lithium chloride. In the cathode reaction zone, the salt film consists of solid solutions and mixture of complex compounds of the system Li, Ni, W ll Cl, Br, O, which reduce the polarization of the electrode, stabilize the discharge plateau, and increase the discharge voltage of the electrochemical cell. It was shown that the reduction process of transition metal ions to metals occurs by the melt mechanism under the mode of diffusion kinetics.
KEYWORDS
thermoactivated chemical current sources; cathode; tungsten oxide; nickel chloride
DOI: 10.31857/S0235010621060128