Gas diffusion electrode for cells

Claim 2

A gas diffusion electrode according to claim 1 in which said carbon powder is activated carbon powder subjected to a waterproofing treatment.

Claim 3

A gas diffusion electrode according to claim 1 in which a plurality of reinforcing members (7) are provided on the gas side face of said electrode.

Claim 4

A gas diffusion electrode for cells comprising a layer (202) participating in the electrode reaction, said layer consisting essentially of carbon powder and a binder therefor, said binder consisting of a powder of a copolymer of tetrafluoroethylene and hexafluoropropylene, and a pre-formed porous fluorocarbon resin paper-like layer (201) consisting of fibers of polytetrafluoroethylene integrally attached to the gas supply side of said layer (202), said layer (202) having a current collector (203) embedded therein.

Claim 5

A gas diffusion electrode for cells comprising a layer (302) participating in the electrode reaction, said layer consisting essentially of carbon powder and a binder therefor said binder consisting of a powder of a copolymer of tetrafluoroethylene and hexafluoropropylene, a pre-formed porous fluorocarbon resin paper-like layer (301) consisting of fiberS of polytetrafluoroethylene disposed on the gas supply side of said layer (302), and a powdery synthetic resin layer (305) of a water repelling and binding nature consisting of a copolymer of tetrafluoroethylene and hexafluoropropylene disposed on the other side of said fluorocarbon resin film (301).

Claim 6

A gas diffusion electrode for cells comprising a first pre-formed porous fluorocarbon resin paper-like layer (401) consisting of fibers of polytetrafluoroethylene, a layer (402) disposed on one side of said first fluorocarbon resin paper-like layer (401) and participating in the electrode reaction, said layer (402) consisting essentially of carbon powder and a binder therefor, said binder consisting of a powder of a copolymer of tetrafluoroethylene and hexafluoropropylene, a powdery synthetic resin layer (405) of a water repelling and binding nature consisting of a copolymer of tetrafluoroethylene and hexafluoropropylene disposed on the other side of said first fluorocarbon resin paper-like layer, and a second pre-formed porous fluorocarbon resin paper-like layer (401'') consisting of fibers of polytetrafluoroethylene disposed on the other side of said powdery synthetic layer (405).

Claim 7

A gas diffusion electrode for cells comprising a pre-formed porous fluorocarbon resin paper-like layer (501) consisting of fibers of polytetrafluoroethylene, a powdery synthetic resin layer (505) of water repelling and binding nature consisting of a copolymer of tetrafluoroethylene and hexafluoropropylene disposed on one side of said fluorocarbon resin paper-like layer (501), and a layer (502) disposed on the other side of said powdery synthetic resin layer (505) and participating in the electrode reaction, said layer (502) consisting essentially of carbon powder and a binder therefor, said binder consisting of a powder of a copolymer of tetrafluoroethylene and hexafluoropropylene.

Claim 8

A gas diffusion electrode for cells comprising a pre-formed porous fluorocarbon resin paper-like layer (601) consisting of fibers of polytetrafluoroethylene, a current collector (603) integrally bonded to said film (601) on one side thereof, a layer (602) consisting essentially of carbon powder and a binder therefor, said binder consisting of a powder of a copolymer of tetrafluoroethylene and hexafluoropropylene disposed on the collector side of said fluorocarbon resin paper-like layer (601), and a powdery synthetic resin layer (605) of a water repelling and binding nature consisting of a copolymer of tetrafluoroethylene and hexafluoropropylene disposed on the other side of said fluorocarbon resin paper-like layer (601).

Claim 9

A gas diffusion electrode for cells comprising a layer participating in the electrode reaction, said layer consisting essentially of carbon powder and binder therefor, said binder consisting of a powder of a copolymer of tetrafluoroethylene and hexafluoropropylene, and a porous fluorocarbon resin paper-like layer consisting of fibers of polytetrafluoroethylene embedded in said layer participating in the electrode reaction.

Claim 10

A method for making a gas diffusion electrode as described in claim 2, characterized by coating a mixture of carbon powder and a solution of said copolymer binder on one face of said pre-formed porous fluorocarbon resin film paper-like oayer to obtain an integrally bonded electrode structure.