Abstract: A process for preparing a metallic cadmium powder for use in a nickel-cadmium by heat melting metallic cadmium in an evaporator, introducing an inert gas into the evaporator to discharge cadmium vapor along with the inert gas into a cooler, and collecting the resulting metallic cadmium powder, wherein the process condition is regulated such that at least one of the following conditions (1) and (2) can be satisfied:(1) the amount of the inert gas flow introduced into the evaporator is at least 30 Nl/g of cadmium vapor while the direction of introducing the inert gas into the evaporator is set against the surface of the molten cadmium; and(2) the temperature of the molten cadmium in the evaporator and the amount of the inert gas flow introduced into the evaporator are set such that the following formulae can be satisfied:log y.gtoreq.8.8.times.10.sup.-3 x-5.3 (600.ltoreq.x.ltoreq.900), andlog y.gtoreq.1.8.times.10.sup.-3 x-0.96 (330.ltoreq.x.ltoreq.600),wherein x is the temperature (.degree.C.

Abstract: An active material for the positive electrode of a lead-accumulator and a lead-accumulator utilizing the active material are provided, the active material consisting of lead oxide as the principal component and at least one component selected from the group consisting of bismuth, bismuth compounds, thallium and thallium compounds as an additive which is effective to improve the energy utilization and the lifetime of the accumulator.