Lithium ion battery using crosslinkable separator
AssigneeAsahi Kasei Kabushiki Kaisha
InventorsXun Zhang, Ryo Kuroki, Yuki Fukunaga, Hiromi Kobayashi, Mitsuko Saito
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Abstract
A separator for an electricity storage device comprising a silane-modified polyolefin, wherein silane crosslinking reaction of the silane-modified polyolefin is initiated when it contacts with the electrolyte solution, as well as a method for producing the separator.
Claims22
A separator for an electricity storage device comprising a silane-modified polyolefin, wherein a silane crosslinking reaction of the silane-modified polyolefin is initiated when the separator for an electricity storage device contacts with an electrolyte solution.
A separator for an electricity storage device comprising a silane-modified polyolefin, wherein silane crosslinking reaction of the silane-modified polyolefin takes place when the separator for an electricity storage device contacts with an electrolyte solution.
A method for producing a separator for an electricity storage device, which comprises the following steps:
- (1) a sheet-forming step in which a silane-modified polyolefin, polyethylene and a plasticizer are extruded into a sheet using an extruder, cooled to solidification and shaped into a molded sheet;
- (2) a stretching step in which the molded sheet is subjected to biaxial stretching to a 20-fold to 250-fold area increase to form a stretched sheet;
- (3) a porous body-forming step in which the plasticizer is extracted from the stretched sheet to form a porous body;
- (4) a heat treatment step in which the porous body is subjected to heat treatment and subjected to stretching and relaxation in the transverse direction to obtain a heat-treated porous body;
- (8B) a coating step in which an inorganic porous layer including inorganic particles and a resin binder is formed on at least one surface of the heat-treated porous body to form a silane-crosslinking precursor;
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- (9) an assembly step in which a laminated stack or wound body of electrodes and the silane-crosslinking precursor, and a nonaqueous electrolyte solution, are housed in an exterior body, contacting the silane-crosslinking precursor with the nonaqueous electrolyte solution.
Dependencies are inferred from the claim text.