Samsung Sdi Co., Inc.

Daehyun Hong

Imhyuck Bae

Sangho Lee

Dowon Kim

Jihyun Chun

Jaehyun Cho

Jinwoo Kim

Byung-Soo Kim

Jinseong Park

Seyeong Kang

Suna Lee

Taejoon Park

Hyunwook Jung

The present invention relates to a separator for a lithium secondary battery and a lithium secondary battery including the separator, the separator for a lithium secondary battery including: a polyolefin-based porous substrate; and a coating layer on at least one surface of the polyolefin-based porous substrate, wherein a coefficient of performance Q1 of the polyolefin-based porous substrate as represented by Equation 1 is greater than or equal to 1.2 (gf/nm·μm), a coefficient of performance Q2 of the polyolefin-based porous substrate as represented by Equation 2 is greater than or equal to 0.25 (gf/nm·%), and the coating layer includes a binder and inorganic particles. Detailed descriptions of Equations 1 and 2 are as described in the specification.

Separator for lithium secondary battery and lithium secondary battery comprising same

Provided is a separator for a secondary battery including a porous substrate and a coating layer disposed on at least one surface of the porous substrate. The coating layer includes a first fluorine-based binder including a vinylidene fluoride (VDF)-derived unit and a hexafluoropropylene (HFP)-derived unit, and a second fluorine-based binder including vinylidene fluoride (VDF)-derived unit and a tetrafluoroethylene (TFE)-derived unit, the hexafluoropropylene (HFP)-derived unit is included in an amount of less than or equal to 5 mol % based on 100 mol % of the first fluorine-based binder, the tetrafluoroethylene (TFE)-derived unit is included in an amount of greater than 10 mol % and less than or equal to 40 mol % based on 100 mol % of the second fluorine-based binder.

Separator for secondary battery and lithium secondary battery comprising same

A method of preparing a composite separator for a lithium battery includes: coating a binder composition on one side or both sides of a porous substrate; hot-air drying the porous substrate coated with the binder composition; and supplying a non-solvent during the hot-air drying, such that a porous layer is on one side or both sides of the porous substrate, wherein the binder composition includes a good-solvent, a binder, and inorganic particles, an amount of the non-solvent supplied during the hot-air drying is from 12 g/mto 17 g/m, and a ratio (e) of the hot-air supply speed to the moving speed of the porous substrate per unit transit time in the hot-air dryer is from 2.2 to 5.0.

Method for preparing composite separator including controlling amount of non-solvent supplied during hot-air drying, composite separator including porous substrate with fluorine-based resin porous layer with more small-diameter pores than large-diameter pores, and lithium battery comprising composite separator

This application relates to a separator for a rechargeable battery. The separator includes a porous substrate and a coating layer on at least one surface of the porous substrate. The coating layer includes a binder including a fluorine-based binder and a (meth)acryl-based binder, and a filler. The fluorine-based binder includes a first structural unit derived from vinylidene fluoride and a second structural unit derived from at least one monomer of hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, ethylene tetrafluoride, and ethylene monomers, and the second structural unit is included in an amount of 10 wt % or less with respect to the fluorine-based binder. The fluorine-based binder includes a first fluorine-based binder having a weight average molecular weight of 800,000 to 1,500,000 and a second fluorine-based binder having a weight average molecular weight of less than or equal to 600,000. The (meth)acryl-based binder has pencil hardness of 5H or higher.

Separator for rechargeable battery and lithium rechargeable battery comprising same

A coating composition is used to prepare a separator for a rechargeable lithium battery. The coating composition includes inorganic particles, a binder, a silane-based dispersant, and a polymeric additive, the silane-based dispersant includes a silane-based compound having fewer than 8 carbons in an alkyl main chain, and the polymeric additive includes a fatty acid compound and a polymer polyol. The coating composition may have secured or improved long-term storage stability, and may thus provide for a composite separator having a reduced number of black spot defects after coating the separator.

Inorganic particle coating composition including binder, silane-based dispersant, fatty acid, and polymer polyol, method for preparing separator using the same, and separator and lithium battery employing the separator

A separator for a rechargeable battery, a method of preparing a separator, and a rechargeable lithium battery, the separator including a porous substrate; and at least one coating layer on one surface of the porous substrate, wherein the coating layer includes a fluorine-containing binder, a filler, and an additive, the fluorine-containing binder has a concentration gradient in which a concentration thereof in the coating layer increases toward an outer surface of the separator in a thickness direction of the separator, an infrared spectral intensity of a C&#x2014;F group of the fluorine-containing binder is greater than 0.0030 to less than 0.0050, the additive is a hydrocarbon polymer compound that includes a carboxyl group, and a weight average molecular weight of the hydrocarbon polymer compound is about 5,000 g/mol to about 15,000 g/mol.

Separator for rechargeable battery, method of preparing the same and rechargeable lithium battery including the same

A separator and an electrochemical battery, the separator including a porous substrate; and a porous bonding layer on one surface or both surfaces of the porous substrate, wherein the porous bonding layer includes a first polyvinylidene fluoride-based polymer, the first polyvinylidene fluoride-based polymer including a polyvinylidene fluoride-based homopolymer or a polyvinylidene fluoride-based copolymer that includes a vinylidene fluoride repeating unit and a hexafluoropropylene repeating unit, and a second polyvinylidene fluoride-based polymer, the second polyvinylidene fluoride-based polymer including a vinylidene fluoride repeating unit and a (meth)acrylate repeating unit, or a vinylidene fluoride repeating unit and a repeating unit of a monomer that includes at least one of an epoxy group, a hydroxy group, a carboxyl group, an ester group, or an acid anhydride group.

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Suwon-si, South Korea

Daehyun Hong