Low cost bipolar current collector-separator for electrochemical cells
AssigneeGeneral Electric Company
InventorRichard J. Lawrance
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Abstract
A bipolar current collector-separator for electrochemical cells consists of a molded aggregate of electro-conductive graphite and a thermoplastic fluoropolymer combined in a weight ratio of 2.5:1 to 16:1. The bulk resistivity of such a molded bipolar current collector-separator is less than 4.times.10.sup.-3 ohm inches (.OMEGA. in.). It has excellent corrosion resistance to a variety of feedstocks such as brine, aqueous HCl, etc. and to various electrolysis products such as caustic, chlorine, hydrogen, etc. In one alternative form the anodic side of a current collector-separator for a water electrolyzer is covered by a thin layer of a passivated metallic foil thus protecting the graphite current collector against attack by oxygen.
Claims13
A bipolar current collecting, fluid distributing, cell separating element for electrochemical cells for conducting current from the anode electrode of one cell unit to cathode electrode of the adjacent cell unit comprising:
- (a) a pressure molded aggregate of electrically conductive carbon/graphite particles and thermoplastic fluorocarbon polymer resin particles in a weight ratio of 2.5:1 to 16:1 whereby said molded aggregate has a bulk resistivity which is less than 4.times.10.sup.-3 ohm/inch,
- (b) said molded aggregate having a fluid impervious main body, at least one recessed chamber on one side of said main body and a plurality of spaced, conductive projections extending from the base of said chamber for contacting and permitting current flow between the electrode of adjacent cell unit,
- (c) means communicating with said recessed chambers to permit introduction and removal of fluids.
Dependencies are inferred from the claim text.