Abstract: Novel double chromate compositions having the general formula:MM'(CrO.sub.4).sub.2,wherein M and M' are silver and bismuth, respectively. Methods of making AgBi (CrO.sub.4).sub.2 are characterized by reacting silver dichromate with a bismuth salt to provide equal numbers of silver and bismuth atoms. These double chromate compositions have particular utility in batteries as active positive material. Due to the steadiness of discharge voltage and duration of discharge of batteries employing these double chromate compositions, such batteries are especially adapted for use in clocks and in cardiostimulators or pacemakers.BACKGROUND OF THE INVENTIONThis invention relates to a new chemical composition, and more particularly to a double chromate having the formula MM' (CrO.sub.4).sub.2 where M and M' represent metals, to methods of making it, and to its use as a positive active material in batteries.From the disclosure of French Pat. No.

Abstract: Method for manufacturing pure silver chromate in which a soluble chromate is made to react with a silver salt in a bichromate medium. The bichromate medium stabilizes the pH and makes it possible to operate in a concentrated medium. The pure product obtained may be used more particularly as a positive active substance in an electrochemical generator having a non-aqueous electrolyte, for it enables avoidance of losses in capacity during idle and storage periods of the generator.