US 3,977,901 A · Metal/air cells and improved air electrodes for use therein

Abstract

Air electrodes for use in electrochemical energy cells which comprise a hydrophilic layer and a hydrophobic layer laminated thereto. The hydrophilic layer essentially comprises a hydrophilic composite which includes I. an oxygen absorption/reduction carbon, Ii. a material selected from the group consisting of A. CuWO.sub.4, NiWO.sub.4, CoWO.sub.4 and WC with 1-20 wt. % Co. for a unifunctional electrode, or B. WS.sub.2, WC, and WC with 1-20 Wt.% Co. for a bi-functional electrode, and Iii. a nonwetting agent containing a polytetrafluoroethylene. A metal current collector is molded into the composite to form a substantially flat hydrophilic layer. A catalyst is preferably incorporated into the composite of a bifunctional electrode to increase cycling life. The hydrophobic layer, comprising a sheet of porous fluorinated ethylene propylene, polypropylene or polytetrafluoroethylene, is laminated to the hydrophilic layer to complete the air electrodes of the invention.

Claims15

Dependent claims

An air electrode for use in electrochemical energy cells comprising:

A. a hydrophilic layer consisting essentially of
1. a hydrophilic composite comprising
i. about 1 part by weight of oxygen absorption/reduction carbon particles having a total surface area of from about 30 to about 600 sq. meters/gram;
ii. about 0.5-4 parts by weight of a low oxygen overvoltage material selected from the group consisting of CuWO.sub.4, NiWO.sub.4 CoWO.sub.4, WS.sub.2, WC and WC fuse sinter coated with 1-20 wt.% Co and mixtures thereof;
iii. an effective amount of a bonding/nonwetting agent including at least polytetrafluoroethylene;
and
iv. an effective amount of a catalyst for oxygen reduction and decomposition of perhydroxides selected from the group consisting of silver, platinum and silver mercury alloy;
and
2. a metal current collector molded into said composite to form a hydrophilic layer;
and
B. a hydrophobic layer laminated to said hydrophilic layer.

8 more elements

An air electrode for use in electrochemical energy cells capable of non destructive charging comprising:

A. a hydrophilic layer consisting essentially of
1. a hydrophilic composite comprising
i. about 1 part by weight of substantially discrete oxygen absorption/reduction carbon black particles having a particle size range of between about 0.005-0.13 microns and a total probable surface area of from about 30-600 sq. meters/gram.;
ii. about 0.5-4 parts by weight of low oxygen over voltage material selected from the group consisting of CuWO.sub.4, NiWO.sub.4, CoWO.sub.4, WS.sub.2, WC and WC fuse sinter coated with 1-20 wt.% Co. and mixtures thereof;
iii. an effective amount of bonding/nonwetting agent including at least polytetrafluoroethylene;
and
iv. an effective amount of a catalyst for oxygen reduction and decomposition of perhydroxides selected from the group consisting of silver, platinum and silver mercury alloy;
and
2. a metal current collector molded into said composite to form a hydrophilic layer;
and
B. a hydrophobic layer laminated to said hydrophilic layer.

8 more elements

A metal/air battery comprising a metal electrode selected from the group consisting of iron, zinc and cadmium;

at least one electrode, effective to allow non destructive battery charging at between about 0.50-0.75 volts above a Hg/HgO reference electrode, spaced apart from said metal electrode, the electrode comprising:
A. a hydrophilic layer consisting essentially of
1. a hydrophilic composite comprising
i. acetylene black carbon;
ii. a low oxygen over voltage material selected from the group consisting of CuWO.sub.4, NiWO.sub.4, CoWO.sub.4, WS.sub.2, WC and WC fuse sinter coated with 1-20 wt.% Co. and mixtures thereof;
iii. an effective amount of bonding/non-wetting agent including at least polytetrafluoroethylene;
and
iv. an effective amount of a catalyst for oxygen reduction and decomposition of perhydroxides selected from the group consisting of silver, platinum and silver mercury alloy;
and
2. A metal current collector molded into said composite to form a substantially flat hydrophilic layer;
and
B. a hydrophobic layer laminated to said hydrophilic layer;
and an alkali hydroxide electrolyte in contact with said metal electrode and the hydrophilic layer of said air electrode.

10 more elements

Dependencies are inferred from the claim text.

Metal/air cells and improved air electrodes for use therein

Life of this patent

Metal/air cells and improved air electrodes for use therein

Life of this patent

Abstract

Claims15