Patent ID: 8652685

Claim:
A process for making an electrochemical cell comprising the steps: (a) preparing an oxygen reduction catalyst via an oxidation-reduction reaction at less than 65° C. in a reaction mixture having a solvent comprising water, an oxidizing agent whose cation is not reduced in the reaction, and a reducing agent whose anion is not oxidized or reduced in the reaction, wherein the oxidizing agent comprises no component that is insoluble in the solvent, the reducing agent comprises no component that is insoluble in the solvent, and at least one of the oxidizing agent and the reducing agent comprises manganese; (b) precipitating the catalyst, wherein the catalyst has a crystallite size less than 10 nm, as calculated from X-ray diffraction using a CrKα radiation source, based on a full width at half maximum for a peak at a 2-theta value of 107° using a Scherrer equation; (c) preparing a catalytic mixture from the catalyst; (d) forming the catalytic mixture into a catalytic layer; (e) preparing a catalytic electrode comprising the catalytic layer; and (f) combining the catalytic electrode with a counter electrode and an electrolyte, with a separator between the catalytic layer of the catalytic electrode and the counter electrode, in a housing comprising an oxygen entry port, wherein the catalytic electrode is accessible to air entering the cell through the air entry port, wherein the catalyst comprises a manganese oxide comprising a molecular formula of K x Mn y O z , wherein x:y is from greater than 0:1 to 1:4 and y:z is from 1:2 to 1:4, and further wherein the catalyst comprises a majority of generally spherical particles having an aspect ratio of 1:1 to 2:1.