Separator having coating containing ethylene carbonate, secondary battery, battery module, battery pack, and power consumption apparatus
The present application provides a separator, a secondary battery, a battery module, a battery pack, and a power consumption apparatus. The separator may include a porous base film and a bonding layer coated on one or both faces of the porous base film. The bonding layer may be composed of ethylene carbonate and an optional nucleating agent.
1 . A separator, comprising a porous base film and a bonding layer coated on one or both faces of the porous base film, the bonding layer consists essentially of ethylene carbonate and a nucleating agent,
wherein the nucleating agent is an inorganic nucleating agent,
the inorganic nucleating agent is one or more of a metal or non-metal oxide, a hydroxide, a fluoride, a sulfate, a silica, a phosphate, a carbonate, or carbon black, and
an amount of the nucleating agent added is greater than or equal to 0.5° and less than or equal to 10% and a mass percentage of the ethylene carbonate is equal to or greater than 90% and less than 100% with respect to a total weight of the bonding layer.
2 . The separator according to claim 1 , wherein the nucleating agent is a powder, and has a particle size expressed by D50 of 0.001-5 μm.
3 . The separator according to claim 1 , wherein a material of the porous base film is one or more of polypropylene, polyethylene, polyethylene terephthalate, polyimide, polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-propylene copolymer, polyamide, polyacrylonitrile, viscose fiber, and silk fiber.
4 . The separator according to claim 1 , wherein the porous base film has a thickness of 5-30 μm.
5 . The separator according to claim 1 , wherein the bonding layer is a continuous coating or a discontinuous coating.
6 . The separator according to claim 1 , wherein the bonding layer has a coverage of 1-100%.
7 . The separator according to claim 1 , wherein the bonding layer has a thickness of 0.1-100 μm.
8 . The separator according to claim 1 , wherein the inorganic nucleating agent is one or more of silica, alumina, and aluminum hydroxide.
9 . The separator according to claim 8 , wherein the silica is a nano silicon micropowder.
10 . The separator according to claim 1 , wherein the amount of the nucleating agent added is 0.05% 0.5%-1%.
11 . The separator according to claim 1 , wherein the mass percentage of the ethylene carbonate is equal to or greater than 99% and less than 100% with respect to a total weight of the bonding layer.
12 . A method for producing a separator, the method comprising: coating a bonding material onto one or both faces of a porous base film, and cooling and solidifying the bonding material in an environment at or below room temperature to form a bonding layer, the bonding material consisting essentially of molten ethylene carbonate, and a nucleating agent,
wherein the nucleating agent is an inorganic nucleating agent, the inorganic nucleating agent is one or more of a metal or non-metal oxide, a hydroxide, a fluoride, a sulfate, a silica, a phosphate, a carbonate, or carbon black, and
an amount of the nucleating agent added is greater than or equal to 0.5% and less than or equal to 10% and a mass percentage of the ethylene carbonate is equal to or greater than 90% and less than 100% with respect to a total weight of the bonding layer.
13 . The method according to claim 12 , further comprising:
melting the ethylene carbonate between 40° C. and 100° C., or mixing the molten ethylene carbonate with the nucleating agent, to obtain the bonding material, wherein a mass fraction ratio of the ethylene carbonate to the nucleating agent is equal to or greater than 90% and less than 100%; and
after the bonding material is coated onto one or both faces of the porous base film, performing cooling at room temperature or at 7-15° C. with a low-temperature auxiliary, to obtain the separator.
14 . The method according to claim 12 , wherein the nucleating agent is one or more of silica, alumina, and aluminum hydroxide.
15 . The method according to claim 12 , wherein an amount of the nucleating agent added is 0.5%-1%.
16 . The method according to claim 12 , wherein the coating is performed by using one or more of roller coating, spray coating, and dip coating.
17 . The method according to claim 12 , wherein the coating has a coating weight of 0.5-20 g/m 2 .