Lockheed Missiles & Space Company, Inc.

William R Momyer

Ernest L Littauer

An improved air cathode structure for use in primary batteries and the like. The cathode structure includes a matrix active layer, a current collector grid on one face of the matrix active layer, and a porous, nonelectrically conductive separator on the opposite face of the matrix active layer, the collector grid and separator being permanently bonded to the matrix active layer. The separator has a preselected porosity providing low IR losses and high resistance to air flow through the matrix active layer to maintain high bubble pressure during operation of the battery. In the illustrated embodiment, the separator was formed of porous polypropylene. A thin hydrophobic film is provided, in the preferred embodiment, on the current collecting metal grid.

Air cathode structure manufacture

An electrochemical cell is shown wherein anode 1 of a reactive metal having an insulating film 2 thereon is separated from cathode 6 by a non-conductive flow screen 4. A porous, expandable element 5 is positioned between screen 4 and cathode 6 to maintain essentially uniform dimensions of the electrolyte flow channel defined by screen 4 as the anode is consumed during cell operation. Preferably, when a multiplicity of cells are electrically connected together, a plurality of separator elements 8 between the respective anodes and cathodes are utilized to ensure that each cell in the multi-cell configuration is subject to essentially identical compression forces in assembly and during discharge.

Electrochemical cell

In a reactive metal-water electrochemical cell, an alkaline electrolyte, containing soluble peroxide ions which improve the uniformity of reaction at the anode, reduces the anode's sensitivity to changes in the hydroxyl ion concentration of the electrolyte, reduces the anode's sensitivity to electrolyte flow rate and reduces the anode's sensitivity to temperature. The improved characteristics of the cell result from the ability of the peroxide ions to stabilize the anode and also to be reduced at a more electronegative potential than is required for the reduction of water. The soluble peroxide ion, HO.sub.2.sup.-, is formed when hydrogen peroxide, sodium peroxide and other soluble inorganic peroxide compounds are dissolved in the alkaline solution.

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Palo Alto, CA, United States of America

William R Momyer