Separator for electrochemical cells
OwnerChristopher F Randell e, Mark A Schubert +1inventors
InventorsChristopher F Randell e, Mark A Schubert, John p Myers
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Abstract
A copolymer of an ethylenically unsaturated carboxylic acid, e.g. acrylic or methacrylic acid, and an aromatic sulphonate or carboxylate, e.g. sodium styrenesulphonate, either alone or supported on a substrate, may be used as a separator for an electrochemical cell.
Claims23
An electrochemical cell comprising an anode and a cathode separated by a separator which is electrically insulating but ionically conducting, wherein said separator comprises a copolymer of an ethylenically unsaturated carboxylic acid of formula I or salt thereof
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- and an aromatic compound of formula II
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- wherein R1, R2, R3, R4, R5 and R6 are selected from the group consisting of a hydrogen atom, an alkyl group having from 1 to 10 carbon atoms, and an aryl group, R7 is selected from the group consisting of a sulphonate, a carboxylate group and an associated balancing cation, and A is selected from the group consisting of a direct bond and an alkyl group having up to 8 atoms.
An electrochemical cell according to claim 1, in which the compound of formula (I) has the formula (Ia):
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- where R1, R2 and R3 are as defined in claim 100.
An electrochemical cell according to any one of the preceeding claims, in which the amount of said polymer is from 10 to 60 gsm.
A process for assembling an electrochemical cell according to any one of the preceding claims, in which:
- an anode or a cathode is inserted into a battery housing;
- a separator is formed on said anode or cathode by applying a solution or dispersion of said copolymer of an acid of formula (I) or salt thereof and said aromatic compound of formula (II) thereon and depositing said copolymer from said solution or dispersion;
- and completing the electrochemical cell.
Dependencies are inferred from the claim text.