Separators for electrochemical cells
AssigneesOptodot Corporation, Sihi GmbH & Co. KG
InventorsZhong Xu, Steven A. Carlson
Life of this patent
Estimating the term…
Abstract
Provided are separators for use in batteries and capacitors comprising (a) at least 50% by weight of an aluminum oxide and (b) an organic polymer, wherein the aluminum oxide is surface modified by treatment with an organic acid to form a modified aluminum oxide, and wherein the treatment provides dispersibility of the aluminum oxide in aprotic solvents such as N-methyl pyrrolidone. Preferably, the organic acid is a sulfonic acid, such as p-toluenesulfonic acid. Also preferably, the organic polymer is a fluorinated polymer, such as polyvinylidene fluoride. Also provided are electrochemical cells and capacitors comprising such separators.
Claims36
A separator for an electric current producing cell comprising a microporous layer, the microporous layer comprising:
- (a) a modified hydrated aluminum oxide formed by surface treating hydrated aluminum oxide with a sulfonic acid to provide the modified hydrated aluminum oxide with dispersibility in aprotic solvents;
- and
- (b) an organic polymer that is not soluble in water or alcohols.
A separator for an electric current producing cell comprising a microporous layer, the microporous layer comprising:
- (a) a modified hydrated aluminum oxide formed by surface treating hydrated aluminum oxide with a sulfonic acid to provide the modified hydrated aluminum oxide with dispersibility in aprotic solvents;
- and
- (b) an organic polymer;
- wherein the separator is flame retardant and does not melt at temperatures lower than 300° C.
An electrochemical cell comprising:
- an anode,
- a cathode,
- an organic electrolyte comprising a lithium salt, and
- a separator interposed between the anode and the cathode, wherein the separator comprises a microporous layer, the microporous layer comprising:
- (a) a modified hydrated aluminum oxide formed by surface treating hydrated aluminum oxide with a sulfonic acid to provide the modified hydrated aluminum oxide with dispersibility in aprotic solvents;
- and
- (b) an organic polymer that is not soluble in water or alcohols.
A method of making a battery separator for use in an electric current producing cell comprising the steps of:
- (a) preparing a dispersion of modified aluminum oxide, wherein the modified hydrated aluminum oxide has been formed by treatment with a sulfonic acid to provide the modified hydrated aluminum oxide with dispersibility in aprotic solvents;
- (b) preparing an organic polymer solution comprising an organic polymer that is not soluble in water or alcohols;
- (c) mixing the dispersion of Step (a) and the solution of Step (b);
- and
- (d) coating the mixture of Step (c) onto a substrate.
A method of making an electric current producing cell comprising the steps of:
- (a) providing an anode;
- (b) providing a cathode;
- and
- (c) interposing a microporous separator between the anode and the cathode to form a separator/electrode cell, wherein the microporous separator comprises a microporous layer comprising:
- a modified hydrated aluminum oxide formed by surface treating hydrated aluminum oxide with a sulfonic acid to provide the modified hydrated aluminum oxide with dispersibility in aprotic solvents;
- and an organic polymer that is not soluble in water or alcohols.
Dependencies are inferred from the claim text.