Densification of CMD by the chlorate reaction and properties of the product. Chlorate hanno ni yoru CMD no jushitsuka shori to sono seiseibutsu no bussei

The chemically synthesized manganese dioxide (CMD) was studied in densification by the chlorate reaction (CR). The battery is not so sufficiently filled with CMD, as low in apparent density, that sufficient discharge capacity can not be obtained. The CR is a method to heighten the apparent density of manganese dioxide, as produced in CMD pore, by the change of chloric acid to hydrochloric acid, in solution containing CMD and M {sup 2+}. The CR was high in reaction speed with highness in acid concentration. In case of low acid concentration, the reaction, if going as far as a high value in weight ratio (CR%) of CR-produced manganese dioxide to total manganese dioxide, stops with pore capacity lost. But in case of high acid concentration, reaction-produced particles are formed, through further proceeding with reaction, around particles to be treated. Manganese dioxide starts to be produced where pore is large in diameter. The crystalline structure is of gamma-manganese dioxide in the nitric acid system and more develops in case of low acid concentration. That structure in the sulfuric acid is of gamma and alpha in case of low and high acid concentrations, respectively. The crystalline structure is considerably influenced by the acid concentration and CR%. 10 refs., 8 figs.