CN115966789A - Battery diaphragm, preparation method thereof, battery and vehicle - Google Patents
Battery diaphragm, preparation method thereof, battery and vehicle Download PDFInfo
- Publication number
- CN115966789A CN115966789A CN202310084587.8A CN202310084587A CN115966789A CN 115966789 A CN115966789 A CN 115966789A CN 202310084587 A CN202310084587 A CN 202310084587A CN 115966789 A CN115966789 A CN 115966789A
- Authority
- CN
- China
- Prior art keywords
- diaphragm
- battery
- microcapsules
- matrix
- heat
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Cell Separators (AREA)
Abstract
The invention provides a battery diaphragm and a preparation method thereof, a battery and a vehicle. In the cycle process of the battery, along with the extension of the cycle time of the battery, the microcapsules arranged in and/or on the surface of the diaphragm matrix are broken, and the electrolyte additive in the microcapsules flows out, so that the electrolyte additive in the electrolyte gradually consumed in the battery is supplemented, and the cycle life of the battery is prolonged; the battery diaphragm provided by the invention is provided with the microcapsules in the diaphragm matrix and/or on the surface of the diaphragm matrix, so that the cycle life of the battery is prolonged on the basis of not reducing the energy density of a battery core; moreover, the battery separator is low in manufacturing cost.
Description
Technical Field
The invention belongs to the technical field of batteries, relates to a battery diaphragm, and particularly relates to a battery diaphragm, a preparation method of the battery diaphragm, a battery and a vehicle.
Background
With the rapid development of the battery industry, the application of the lithium ion battery in the energy storage field and the electric automobile is wider and wider, and the requirement on the cycle life of the battery core is higher and higher. The design of the existing long-circulating battery core is realized by selecting positive and negative active substances and matching electrolyte, the diaphragm is usually a common polyolefin diaphragm or a polyolefin diaphragm coated with ceramic, no special design is made, when the positive and negative active substances and an electrochemical system are determined, the circulation is basically determined, the diaphragm is an inert substance in the battery and does not participate in the reaction, and therefore, the battery circulation is not promoted.
The battery diaphragm disclosed at present is not specially designed, and the cycle life of the battery cannot be prolonged under the condition of not influencing the energy density of the battery. Therefore, it is important to develop and design a novel battery separator, a preparation method thereof, a battery and a vehicle.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a battery diaphragm, a preparation method thereof, a battery and a vehicle, wherein in the circulation process of the battery, along with the extension of the battery circulation time, microcapsules arranged in and/or on the surface of a diaphragm matrix are broken, and an electrolyte additive in the microcapsules flows out, so that the electrolyte additive in the electrolyte gradually consumed in the battery is supplemented, and the extension of the battery circulation life is realized; the battery diaphragm provided by the invention is provided with the microcapsules in the diaphragm matrix and/or on the surface of the diaphragm matrix, so that the cycle life of the battery is prolonged on the basis of not reducing the energy density of a battery core; moreover, the battery separator is low in manufacturing cost.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a battery separator comprising a separator matrix having microcapsules disposed therein and/or on a surface thereof, the microcapsules comprising a protective layer wall and an electrolyte additive within the protective layer wall.
Preferably, a heat-resistant material is further provided on the inside and/or surface of the separator base.
Preferably, the heat-resistant material includes a ceramic material and/or a heat-resistant polymer material.
Preferably, the ceramic material comprises any one of alumina, boehmite, silica or titania or a combination of at least two thereof.
Preferably, the heat-resistant polymer material comprises any one of or a combination of at least two of aromatic polyamide fiber, polymethyl methacrylate or polyimide.
Preferably, a bonding material layer is arranged on the surface of the membrane substrate, and microcapsules are arranged in the bonding material layer.
Preferably, the heat-resistant material is disposed in the adhesive material layer.
Preferably, the material of the binding material layer includes any one of polyvinylidene fluoride, polymethyl methacrylate, polyacrylate or modified polyacrylic acid or a combination of at least two of them.
Preferably, the material of the protective layer capsule wall comprises polymer.
Preferably, the polymer comprises any one of polyamide, polyurethane, polyethylene, polypropylene, polyvinylpyrrolidone, epoxy resin or sodium alginate or a combination of at least two thereof.
Preferably, the electrolyte additive includes an inorganic additive and/or an organic additive.
Preferably, the inorganic additive comprises an inorganic film-forming additive.
Preferably, the inorganic film-forming additive comprises any one or a combination of at least two of lithium tetrafluoroborate, lithium hexafluorophosphate, lithium difluorooxalato borate, lithium bisoxalato borate, lithium difluorooxalato phosphate, lithium tetrafluorooxalato phosphate, or lithium difluorosulfonimide.
Preferably, the organic additive comprises any one of fluoro carbonate, chloro carbonate, bromo carbonate, succinonitrile, adiponitrile, vinylene carbonate or fluoro ethylene carbonate or a combination of at least two of the same.
Preferably, the protective layer capsule wall contains an electrolyte solvent, and the electrolyte solvent comprises any one or a combination of at least two of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl acrylate, ethyl propionate and methyl acetate.
Preferably, the membrane substrate includes a polyolefin-based membrane and/or a non-woven membrane.
In a second aspect, the present invention provides a method for preparing a battery separator according to the first aspect, the method comprising:
mixing the raw materials of the diaphragm matrix with the microcapsules, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
or firstly adopting a diaphragm preparation process to obtain a diaphragm matrix, and then coating the microcapsule on the diaphragm matrix to obtain the battery diaphragm;
or mixing the raw materials of the diaphragm matrix and part of the microcapsules, obtaining the diaphragm matrix containing the microcapsules by adopting a diaphragm preparation process, and coating the rest microcapsules on the diaphragm matrix to obtain the battery diaphragm.
As a preferable technical scheme of the preparation method, the preparation method comprises the following steps:
mixing the raw materials of the diaphragm matrix, the microcapsules and the heat-resistant material, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
or firstly adopting a diaphragm preparation process to obtain a diaphragm matrix, and then mixing the microcapsule, the heat-resistant material, the binder and the solvent and coating the mixture on the diaphragm matrix to obtain the battery diaphragm;
or mixing the raw materials of the diaphragm matrix, partial microcapsules and partial heat-resistant materials, obtaining the diaphragm matrix containing the microcapsules and the heat-resistant materials by adopting a diaphragm preparation process, and coating the rest microcapsules, the rest heat-resistant materials, the binder and the solvent on the diaphragm matrix to obtain the battery diaphragm.
In a third aspect, the present invention provides a battery comprising a battery separator as described in the first aspect.
In a fourth aspect, the invention provides a vehicle comprising a battery according to the third aspect.
Compared with the prior art, the invention has the following beneficial effects:
in the cycle process of the battery, because the negative active material embeds lithium, the negative pole piece is expanded to extrude the battery diaphragm, the extrusion force borne by the battery diaphragm is continuously increased along with the extension of the cycle time of the battery, so that the microcapsules arranged in the diaphragm matrix and/or on the surface of the diaphragm matrix are broken, and the electrolyte additive in the microcapsules flows out, thereby supplementing the electrolyte additive in the electrolyte gradually consumed in the battery, and realizing the extension of the cycle life of the battery;
the battery diaphragm provided by the invention is provided with the microcapsules in the diaphragm matrix and/or on the surface of the diaphragm matrix, so that the cycle life of the battery is prolonged on the basis of not reducing the energy density of a battery core; moreover, the battery separator is low in manufacturing cost.
Detailed Description
The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
In one embodiment, the invention provides a battery separator, which comprises a separator substrate, wherein microcapsules are arranged in and/or on the surface of the separator substrate, and the microcapsules comprise a protective layer capsule wall and an electrolyte additive in the protective layer capsule wall.
The invention discloses a diaphragm substrate, which is characterized in that microcapsules are arranged in and/or on the surface of the diaphragm substrate, and the microcapsules are arranged in the diaphragm substrate, on the surface of the diaphragm substrate or on both the surface and the interior of the diaphragm substrate.
After the conventional battery is assembled and injected with liquid, the battery can be normally used only by pre-charging. A certain amount of additives are consumed during battery formation, an SEI film is formed on the surface of a negative electrode, and the additives remaining in the electrolyte after battery formation can help the battery to repair the SEI film in the circulation process, so that the battery can be helped to prolong the circulation. If the cycle service life of the battery is prolonged, the cycle service life of the battery can be prolonged by adding more electrolyte additives, but if the additives are directly added into the initial electrolyte, the SEI film formed in the formation process is too thick, the internal resistance of the battery is increased, and the cycle is not facilitated. Therefore, the battery diaphragm is designed, the microcapsules are arranged inside and/or on the surface of the diaphragm base body, and the electrolyte additive is filled in the microcapsules. In the cycle process of the battery, because the negative active material embeds lithium, the negative pole piece is caused to expand and extrude the diaphragm of the battery, along with the extension of the cycle time of the battery, the extrusion force born by the diaphragm of the battery is continuously increased, so that the microcapsules arranged in the inner part and/or on the surface of the diaphragm matrix are broken, and the electrolyte additive in the microcapsules flows out, thereby supplementing the electrolyte additive in the electrolyte gradually consumed in the battery, and further realizing the extension of the cycle life of the battery.
The battery diaphragm provided by the invention is provided with the microcapsules in the diaphragm matrix and/or on the surface of the diaphragm matrix, so that the cycle life of the battery is prolonged on the basis of not reducing the energy density of a battery core; moreover, the battery separator is low in manufacturing cost.
Further, a heat-resistant material is provided inside and/or on the surface of the separator base.
The diaphragm substrate is internally and/or superficially provided with heat-resistant materials, wherein the heat-resistant materials are arranged inside the diaphragm substrate, the heat-resistant materials are arranged on the surface of the diaphragm substrate, or the heat-resistant materials are arranged inside and on the surface of the diaphragm substrate.
The heat-resistant material is arranged in and/or on the surface of the diaphragm substrate, so that the heat resistance of the battery diaphragm is improved, and the safety performance of the battery is improved.
Further, the heat-resistant material includes a ceramic material and/or a heat-resistant polymer material.
Further, the ceramic material comprises any one or combination of at least two of alumina, boehmite, silica, or titania, and typical, but non-limiting combinations include combinations of alumina and boehmite, alumina and silica, alumina and titania, boehmite and silica, silica and titania, alumina, boehmite, silica and titania, or alumina, boehmite, silica and titania.
Further, the heat-resistant polymer material includes any one or a combination of at least two of aramid fiber, polymethyl methacrylate, or polyimide, and typical but non-limiting combinations include a combination of aramid fiber and polymethyl methacrylate, a combination of polymethyl methacrylate and polyimide, or a combination of aramid fiber, polymethyl methacrylate, and polyimide.
Furthermore, a bonding material layer is arranged on the surface of the diaphragm substrate, and microcapsules are arranged in the bonding material layer.
The bonding material layer is directly arranged on the surface of the diaphragm substrate, and the microcapsules are arranged in the bonding material layer, so that the adhesion force of the microcapsules and the diaphragm substrate is increased, and the microcapsules are prevented from falling off from the surface of the diaphragm substrate.
Further, a heat-resistant material is provided inside the adhesive material layer.
The heat-resistant material is arranged in the bonding material layer, so that the adhesion force between the heat-resistant material and the diaphragm substrate is increased, and the heat-resistant material is prevented from falling off from the surface of the diaphragm substrate.
Further, the material of the adhesive material layer includes any one of polyvinylidene fluoride, polymethyl methacrylate, polyacrylate or modified polyacrylic acid or a combination of at least two of them, and typical but non-limiting combinations include a combination of polyvinylidene fluoride and polymethyl methacrylate, a combination of polyvinylidene fluoride and polyacrylate, a combination of polyvinylidene fluoride and modified polyacrylic acid, a combination of polymethyl methacrylate and polyacrylate, a combination of polyacrylate and modified polyacrylic acid, a combination of polyvinylidene fluoride, polymethyl methacrylate and polyacrylate, a combination of polyvinylidene fluoride, polyacrylate and modified polyacrylic acid, a combination of polymethyl methacrylate, polyacrylate and modified polyacrylic acid, or a combination of polyvinylidene fluoride, polymethyl methacrylate, polyacrylate and modified polyacrylic acid.
Furthermore, the material of the capsule wall of the protective layer comprises polymer.
Further, the polymer includes any one or a combination of at least two of polyamide, polyurethane, polyethylene, polypropylene, polyvinylpyrrolidone, epoxy resin or sodium alginate, typical but non-limiting combinations include a combination of polyamide and polyurethane, a combination of polyurethane and polyethylene, a combination of polypropylene and polyvinylpyrrolidone, a combination of epoxy resin and sodium alginate, a combination of polyamide, polyurethane and polyethylene, a combination of polyethylene, polypropylene and polyvinylpyrrolidone, a combination of polyvinylpyrrolidone, epoxy resin and sodium alginate, a combination of polyamide, polyurethane, polyethylene and polypropylene, or a combination of polyethylene, polypropylene, polyvinylpyrrolidone and epoxy resin.
Further, the electrolyte additive includes any one of inorganic additives and/or organic additives or a combination of at least two thereof.
Further, the inorganic additives include inorganic film-forming additives.
Further, the inorganic film-forming additive includes any one or a combination of at least two of lithium tetrafluoroborate, lithium hexafluorophosphate, lithium difluorooxalato borate, lithium bisoxalato borate, lithium difluorooxalato phosphate, lithium tetrafluorooxalato phosphate, or lithium difluorosulfonimide, and typical but non-limiting combinations include a combination of lithium tetrafluoroborate and lithium hexafluorophosphate, a combination of lithium hexafluorophosphate and lithium difluorooxalato borate, a combination of lithium bisoxalato borate and lithium difluorooxalato phosphate, a combination of lithium difluorooxalato phosphate and lithium tetrafluorooxalato phosphate, a combination of lithium tetrafluorooxalato phosphate and lithium difluorosulfonimide, a combination of lithium tetrafluoroborate, lithium hexafluorophosphate and lithium difluorooxalato borate, or a combination of lithium hexafluorophosphate, lithium difluorooxalato borate, lithium bisoxalato borate and lithium difluorooxalato phosphate.
Further, the organic additive includes any one or a combination of at least two of fluoro carbonate, chloro carbonate, bromo carbonate, succinonitrile, adiponitrile, vinylene carbonate or fluoroethylene carbonate, and typical but non-limiting combinations include a combination of fluoro carbonate and chloro carbonate, a combination of chloro carbonate and bromo carbonate, a combination of bromo carbonate and succinonitrile, a combination of adiponitrile and vinylene carbonate, a combination of vinylene carbonate and fluoroethylene carbonate, a combination of fluoro carbonate, chloro carbonate and bromo carbonate, or a combination of succinonitrile, adiponitrile, vinylene carbonate and fluoroethylene carbonate.
Further, the protective layer capsule wall contains an electrolyte solvent, and the electrolyte solvent comprises any one or a combination of at least two of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl acrylate, ethyl propionate and methyl acetate, and typical but non-limiting combinations include a combination of ethylene carbonate and propylene carbonate, a combination of propylene carbonate and dimethyl carbonate, a combination of ethyl methyl carbonate and diethyl carbonate, a combination of ethyl acrylate and ethyl propionate, a combination of ethyl propionate and methyl acetate, a combination of ethylene carbonate, propylene carbonate and dimethyl carbonate, or a combination of propylene carbonate, dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate.
Further, the diaphragm substrate includes a polyolefin diaphragm and/or a non-woven diaphragm.
In another embodiment, the present invention provides a method for preparing the above battery separator, the method comprising:
mixing the raw materials of the diaphragm matrix with the microcapsules, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
or firstly adopting a diaphragm preparation process to obtain a diaphragm matrix, and then coating the microcapsule on the diaphragm matrix to obtain the battery diaphragm;
or mixing the raw materials of the diaphragm matrix and part of the microcapsules, obtaining the diaphragm matrix containing the microcapsules by adopting a diaphragm preparation process, and coating the rest microcapsules on the diaphragm matrix to obtain the battery diaphragm.
The preparation process of the diaphragm is a conventional diaphragm preparation process in the prior art.
The method of coating the microcapsules on the separator substrate in the present invention may be to mix the microcapsules with a solvent and then coat the microcapsules or to bond the microcapsules to the separator substrate using a binder, but is not limited to the above-mentioned coating method, and other coating methods not mentioned above may be applied.
The preparation method of the battery diaphragm provided by the invention realizes the arrangement of the microcapsules in the inner part and/or on the surface of the diaphragm matrix under the condition of not increasing additional working procedures, has simple process and lower cost, and is beneficial to large-scale popularization and use.
Further, the preparation method comprises the following steps:
mixing the raw materials of the diaphragm matrix, the microcapsules and the heat-resistant material, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
or firstly adopting a diaphragm preparation process to obtain a diaphragm matrix, and then mixing the microcapsule, the heat-resistant material, the binder and the solvent and coating the mixture on the diaphragm matrix to obtain the battery diaphragm;
or mixing the raw materials of the diaphragm matrix, partial microcapsules and partial heat-resistant materials, obtaining the diaphragm matrix containing the microcapsules and the heat-resistant materials by adopting a diaphragm preparation process, and coating the rest microcapsules, the rest heat-resistant materials, the binder and the solvent on the diaphragm matrix to obtain the battery diaphragm.
The invention mixes the microcapsule, the heat-resistant material, the binder and the solvent, coats the mixture on the diaphragm substrate and dries the mixture to obtain the battery diaphragm with the surface provided with the binder material layer, and the inside of the binder material layer is provided with the microcapsule and the heat-resistant material.
The solvent in the present invention includes deionized water and/or N-methylpyrrolidone, but is not limited to the listed solvent types, and other solvents not listed as solvents may be suitable.
The preparation method realizes that the microcapsule and the heat-resistant material are simultaneously arranged in and/or on the surface of the diaphragm matrix under the condition of not increasing additional working procedures, and has simple process and lower cost.
In another embodiment, the invention provides a battery comprising a battery separator as described above.
In another embodiment, the invention provides a vehicle comprising the battery described above.
Example 1
The embodiment provides a battery diaphragm, which comprises a polyolefin diaphragm, wherein a microcapsule is arranged in the polyolefin diaphragm, the microcapsule comprises a protective layer capsule wall and fluoro-carbonate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsule is made of polyamide;
the preparation method of the battery separator comprises the following steps:
mixing the raw materials of the polyolefin diaphragm with the microcapsule, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
wherein, the polyolefin diaphragm comprises the following raw materials: polyethylene and polypropylene.
Example 2
The embodiment provides a battery diaphragm, which comprises a non-woven fabric diaphragm, wherein a microcapsule is arranged in the non-woven fabric diaphragm, the microcapsule comprises a protective layer capsule wall and a propylene carbonate solution of chlorocarbonate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsule is made of polyurethane;
the preparation method of the battery separator comprises the following steps:
mixing the raw materials of the non-woven fabric diaphragm with the microcapsules, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
wherein, the raw materials of the non-woven fabric diaphragm comprise: polyimide materials and polyethylene terephthalate.
Example 3
The embodiment provides a battery diaphragm, which comprises a polyolefin diaphragm, wherein a microcapsule and aluminum oxide are arranged in the polyolefin diaphragm, the microcapsule comprises a protective layer capsule wall and lithium hexafluorophosphate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsule is made of sodium alginate;
the preparation method of the battery diaphragm comprises the following steps:
mixing the raw materials of the polyolefin diaphragm, the microcapsules and the aromatic polyamide fiber, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
wherein, the polyolefin diaphragm comprises the following raw materials: polyethylene and polypropylene.
Example 4
The embodiment provides a battery diaphragm, which comprises a non-woven fabric diaphragm, wherein a microcapsule and aluminum oxide are arranged in the non-woven fabric diaphragm, the microcapsule comprises a protective layer capsule wall and ethyl propionate solution of lithium difluoro (oxalato) borate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsule is made of polyethylene;
the preparation method of the battery separator comprises the following steps:
mixing the raw materials of the non-woven fabric diaphragm, the microcapsule and the polymethyl methacrylate, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
wherein, the raw materials of the non-woven fabric diaphragm comprise: polyimide materials and polyethylene terephthalate.
Example 5
The embodiment provides a battery diaphragm, which comprises a non-woven fabric diaphragm, wherein a polyvinylidene fluoride layer is arranged on the surface of the non-woven fabric diaphragm, a microcapsule and titanium oxide are arranged in the polyvinylidene fluoride layer, the microcapsule comprises a protective layer capsule wall and lithium tetrafluoroborate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsule is made of polyethylene;
the preparation method of the battery separator comprises the following steps:
firstly, a non-woven fabric diaphragm is obtained by adopting a diaphragm preparation process, and then the microcapsule, titanium oxide, polyvinylidene fluoride and a solvent are mixed and coated on the non-woven fabric diaphragm to obtain the battery diaphragm.
Example 6
The embodiment provides a battery diaphragm, which comprises a polyolefin diaphragm, wherein a polyacrylate layer is arranged on the surface of the polyolefin diaphragm, a microcapsule and titanium oxide are arranged in the polyacrylate layer, the microcapsule comprises a protective layer capsule wall and a methyl ethyl carbonate solution of lithium tetrafluoroborate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsule is made of polypropylene;
the preparation method of the battery separator comprises the following steps:
firstly, a diaphragm preparation process is adopted to obtain a polyolefin diaphragm, and then microcapsules, boehmite, polyacrylate and a solvent are mixed and coated on the polyolefin diaphragm to obtain the battery diaphragm.
Example 7
The embodiment provides a battery diaphragm which comprises a non-woven fabric diaphragm, wherein microcapsules and aluminum oxide are arranged in the non-woven fabric diaphragm, a polymethyl methacrylate layer is arranged on the surface of the non-woven fabric diaphragm, the microcapsules and the aluminum oxide are arranged in the polymethyl methacrylate layer, the microcapsules comprise a protective layer capsule wall and a diethyl carbonate solution of chlorocarbonate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsules is made of polyvinylpyrrolidone;
the preparation method of the battery separator comprises the following steps:
firstly, mixing raw materials of a non-woven fabric diaphragm, partial microcapsules and partial alumina, obtaining the non-woven fabric diaphragm containing the microcapsules and the alumina by adopting a diaphragm preparation process, then mixing the rest microcapsules, the rest alumina, polymethyl methacrylate and a solvent, and coating the mixture on the non-woven fabric diaphragm to obtain a battery diaphragm;
wherein, the raw materials of the non-woven fabric diaphragm comprise: polyimide materials and polyethylene terephthalate.
Example 8
The embodiment provides a battery diaphragm, which comprises a non-woven fabric diaphragm, wherein microcapsules and aluminum oxide are arranged in the non-woven fabric diaphragm, a modified polyacrylic acid layer is arranged on the surface of the non-woven fabric diaphragm, the microcapsules and the aluminum oxide are arranged in the modified polyacrylic acid layer, the microcapsules comprise a protective layer capsule wall and chlorocarbonate in the protective layer capsule wall, and the protective layer capsule wall of the microcapsules is made of epoxy resin;
the preparation method of the battery separator comprises the following steps:
firstly, mixing raw materials of a non-woven fabric diaphragm, partial microcapsules and partial silicon dioxide, obtaining the non-woven fabric diaphragm containing the microcapsules and aluminum oxide by adopting a diaphragm preparation process, then mixing the rest microcapsules, the rest silicon dioxide, the modified polyacrylic acid and a solvent, and coating the mixture on the non-woven fabric diaphragm to obtain a battery diaphragm;
wherein, the raw materials of the non-woven fabric diaphragm comprise: polyimide materials and polyethylene terephthalate.
Comparative example 1
This example provides a battery separator which is the same as example 1 except that the microcapsules provided inside the polyolefin-based separator are omitted.
Comparative example 2
This example provides a battery separator similar to that of example 2, except that microcapsules provided inside the nonwoven fabric separator were omitted.
Comparative example 3
This example provides a battery separator similar to that of example 5, except that microcapsules provided in the polyvinylidene fluoride layer were omitted.
Comparative example 4
This example provides a battery separator which is the same as example 6 except that the microcapsules provided in the polyacrylate layer are omitted.
The preparation process of the separator in the above examples and comparative examples was: mixing the raw materials of the non-woven fabric diaphragm or the polyolefin diaphragm with white oil, heating, melting and uniformly mixing, extruding and stretching to form a film, and extracting low molecular substances by using volatile solvents of dichloromethane and trichloroethylene to form a microporous film;
assembling the battery diaphragm, the positive pole piece and the negative pole piece in the above examples and comparative examples, after injecting liquid, pre-charging to obtain a battery, and performing a cycle performance test and a thermal shrinkage performance test on the obtained battery, wherein the test results are shown in table 1;
the method for testing the cycle performance comprises the following steps: 1C charging at 100% SOC, 1C discharge cycle test, and the number of cycles at which the capacity retention ratio of the battery was 80% as measured is shown in Table 1;
the method for testing the heat shrinkage performance comprises the following steps: the separator was placed in a temperature oven at 130 ℃ for 1 hour, and the dimensions of the separator before and after heating were measured, respectively, for shrinkage = (dimension before shrinkage-dimension after shrinkage)/dimension before shrinkage × 100%, and the degree of thermal shrinkage (%) at 130 ℃ was measured as shown in table 1.
TABLE 1
From table 1, it can be seen:
(1) The battery diaphragm obtained from the embodiments 1 to 8 has more cycle cycles in the cycle performance test, and the battery diaphragm provided by the invention has better cycle stability, and the battery diaphragm provided by the invention is provided with microcapsules in the inner part and/or on the surface of the diaphragm substrate, so that the cycle life of the battery is prolonged on the basis of not reducing the energy density of a battery core; moreover, the manufacturing cost of the battery diaphragm is low;
(2) It can be seen from the comparison between examples 1 and 2 and examples 3 and 4 that the provision of the heat-resistant material inside the separator substrate is advantageous for improving the heat resistance of the battery separator, thereby improving the thermal stability of the battery, because when heat is dissipated during the recycling process of the battery, a large amount of heat is blocked and absorbed by the heat-resistant material, and the temperature rise of the battery is avoided, thereby enhancing the heat resistance of the battery and improving the safety of the battery;
(3) It can be known from the comparison between the examples 1 and 2 and the comparative examples 1 and 2 that the arrangement of the microcapsules in the diaphragm matrix is beneficial to improving the cycle stability of the battery diaphragm, in the cycle process of the battery, because the negative active material embeds lithium, the negative pole piece expands to extrude the battery diaphragm, and along with the extension of the cycle time of the battery, the extrusion force borne by the battery diaphragm is continuously increased, so that the microcapsules arranged in the diaphragm matrix of the battery diaphragm are broken, and the electrolyte additive in the microcapsules flows out, thereby supplementing the electrolyte additive in the electrolyte gradually consumed in the battery, and further realizing the extension of the cycle life of the battery;
(3) It can be known from the comparison between the embodiments 5 and 6 and the comparative examples 3 and 4 that the microcapsules arranged on the surface of the diaphragm substrate are beneficial to improving the cycle stability of the battery diaphragm, in the cycle process of the battery, because the negative active material embeds lithium, the negative pole piece is caused to expand, the battery diaphragm is extruded, along with the extension of the cycle time of the battery, the extrusion force borne by the battery diaphragm is continuously increased, so that the microcapsules arranged on the surface of the diaphragm substrate are broken, the electrolyte additive in the microcapsules flows out, the electrolyte additive in the electrolyte gradually consumed in the battery is supplemented, and the cycle life of the battery is prolonged.
In conclusion, in the cycle process of the battery, the negative electrode active material embeds lithium to cause the negative electrode plate to expand and extrude the battery diaphragm, and the extrusion force borne by the battery diaphragm is continuously increased along with the extension of the cycle time of the battery, so that the microcapsules arranged in the diaphragm matrix and/or on the surface of the diaphragm matrix are broken, and the electrolyte additive in the microcapsules flows out, thereby supplementing the electrolyte additive in the electrolyte gradually consumed in the battery, and further prolonging the cycle life of the battery; the battery diaphragm provided by the invention is provided with the microcapsules in the diaphragm matrix and/or on the surface of the diaphragm matrix, so that the cycle life of the battery is prolonged on the basis of not reducing the energy density of a battery core; moreover, the battery separator is low in manufacturing cost.
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope of the present invention and the disclosure.
Claims (10)
1. The battery diaphragm is characterized by comprising a diaphragm matrix, wherein microcapsules are arranged in and/or on the surface of the diaphragm matrix, and each microcapsule comprises a protective layer diaphragm wall and an electrolyte additive in the protective layer diaphragm wall.
2. The battery separator according to claim 1, wherein a heat-resistant material is further provided inside and/or on the surface of the separator base.
3. The battery separator according to claim 2, wherein the heat-resistant material comprises a ceramic material and/or a heat-resistant polymer material;
preferably, the ceramic material comprises any one of alumina, boehmite, silica or titania or a combination of at least two thereof;
preferably, the heat-resistant polymer material comprises any one of or a combination of at least two of aromatic polyamide fiber, polymethyl methacrylate or polyimide.
4. The battery separator according to claim 2 or 3, wherein a bonding material layer is provided on a surface of the separator substrate, and microcapsules are provided in the bonding material layer;
preferably, the heat-resistant material is arranged in the bonding material layer;
preferably, the material of the bonding material layer includes any one or a combination of at least two of polyvinylidene fluoride, polymethyl methacrylate, polyacrylate or modified polyacrylic acid.
5. The battery separator as claimed in any of claims 1 to 4, wherein the material of the protective layer capsule wall comprises a polymer;
preferably, the polymer comprises any one of polyamide, polyurethane, polyethylene, polypropylene, polyvinylpyrrolidone, epoxy resin or sodium alginate or a combination of at least two of them;
preferably, the electrolyte additive comprises an inorganic additive and/or an organic additive;
preferably, the inorganic additive comprises an inorganic film-forming additive;
preferably, the inorganic film-forming additive comprises any one or a combination of at least two of lithium tetrafluoroborate, lithium hexafluorophosphate, lithium difluorooxalato borate, lithium bisoxalato borate, lithium difluorooxalato phosphate, lithium tetrafluorooxalato phosphate, or lithium difluorosulfonimide;
preferably, the organic additive comprises any one of fluoro carbonate, chloro carbonate, bromo carbonate, succinonitrile, adiponitrile, vinylene carbonate or fluoro ethylene carbonate or a combination of at least two of the same;
preferably, the protective layer capsule wall contains an electrolyte solvent, and the electrolyte solvent comprises any one or a combination of at least two of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl acrylate, ethyl propionate and methyl acetate.
6. The battery separator according to any one of claims 1 to 5, wherein the separator substrate comprises a polyolefin-based separator and/or a non-woven separator.
7. A method for preparing a battery separator as defined in any one of claims 1 to 6, comprising:
mixing the raw materials of the diaphragm matrix with the microcapsules, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
or firstly adopting a diaphragm preparation process to obtain a diaphragm matrix, and then coating the microcapsule on the diaphragm matrix to obtain the battery diaphragm;
or mixing the raw materials of the diaphragm matrix and part of the microcapsules, obtaining the diaphragm matrix containing the microcapsules by adopting a diaphragm preparation process, and coating the rest microcapsules on the diaphragm matrix to obtain the battery diaphragm.
8. The method of manufacturing according to claim 7, comprising:
mixing the raw materials of the diaphragm matrix, the microcapsule and the heat-resistant material, and obtaining the battery diaphragm by adopting a diaphragm preparation process;
or firstly adopting a diaphragm preparation process to obtain a diaphragm matrix, and then mixing the microcapsule, the heat-resistant material, the binder and the solvent and coating the mixture on the diaphragm matrix to obtain the battery diaphragm;
or mixing the raw materials of the diaphragm matrix, part of the microcapsules and part of the heat-resistant material, obtaining the diaphragm matrix containing the microcapsules and the heat-resistant material by adopting a diaphragm preparation process, and then coating the rest of the microcapsules, the rest of the heat-resistant material, the binder and the solvent on the diaphragm matrix to obtain the battery diaphragm.
9. A battery comprising the battery separator of any one of claims 1-6.
10. A vehicle characterized in that the vehicle comprises the battery of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310084587.8A CN115966789A (en) | 2023-02-01 | 2023-02-01 | Battery diaphragm, preparation method thereof, battery and vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310084587.8A CN115966789A (en) | 2023-02-01 | 2023-02-01 | Battery diaphragm, preparation method thereof, battery and vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115966789A true CN115966789A (en) | 2023-04-14 |
Family
ID=87352858
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310084587.8A Pending CN115966789A (en) | 2023-02-01 | 2023-02-01 | Battery diaphragm, preparation method thereof, battery and vehicle |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115966789A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116565334A (en) * | 2023-06-07 | 2023-08-08 | 宁夏宝丰昱能科技有限公司 | Multilayer composite liquid absorption material and preparation method and application thereof |
| CN116742278A (en) * | 2023-08-14 | 2023-09-12 | 中材锂膜(宜宾)有限公司 | Separator, preparation method thereof, electrochemical cell using separator and electricity utilization device |
-
2023
- 2023-02-01 CN CN202310084587.8A patent/CN115966789A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116565334A (en) * | 2023-06-07 | 2023-08-08 | 宁夏宝丰昱能科技有限公司 | Multilayer composite liquid absorption material and preparation method and application thereof |
| CN116742278A (en) * | 2023-08-14 | 2023-09-12 | 中材锂膜(宜宾)有限公司 | Separator, preparation method thereof, electrochemical cell using separator and electricity utilization device |
| CN116742278B (en) * | 2023-08-14 | 2023-10-24 | 中材锂膜(宜宾)有限公司 | Separator, preparation method thereof, electrochemical cell using separator and electricity utilization device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115966789A (en) | Battery diaphragm, preparation method thereof, battery and vehicle | |
| CN106519742B (en) | A kind of fire resistant ceramic modified slurry and the lithium ion battery separator for coating the slurry | |
| CN110197888B (en) | Battery diaphragm and lithium ion battery | |
| Lee et al. | A review of recent developments in membrane separators for rechargeable lithium-ion batteries | |
| JP5193234B2 (en) | Microporous polymer membrane for lithium ion battery and method for producing the same | |
| CN104124427B (en) | Electrode, electrochemical device comprising electrode, and manufacture method of electrode | |
| US20090169984A1 (en) | Composite separator films for lithium-ion batteries | |
| CN107611314B (en) | Lithium ion battery and coating diaphragm thereof | |
| CN101246958B (en) | Lithium ion battery and combination electrode used for the same and production method thereof | |
| CN109841784A (en) | Composite diaphragm for secondary cell and the lithium secondary battery including it | |
| CN111653717A (en) | Preparation method of composite diaphragm, composite diaphragm and lithium ion battery | |
| CN109411676B (en) | Para-aramid coating slurry and preparation method thereof, para-aramid diaphragm and preparation method thereof, and secondary battery | |
| CN104140502B (en) | A kind of lithium ion battery separator binding agent, preparation method and use the barrier film of this binding agent | |
| CN101989651A (en) | Method for preparing cross-linked ceramic-coated separator containing ionic polymer, ceramic-coated separator prepared by the method, and lithium secondary battery using the same | |
| WO2021023196A1 (en) | Lithium ion battery and device | |
| KR101943193B1 (en) | Polymer-Ceramic Hybrid Coating Composition and Method of Making Secondary Battery Separator Employing the Same | |
| CN1930703A (en) | Separator coated with electrolyte-miscible polymer and electrochemical device using the same | |
| CN102263290A (en) | Polymer battery and preparation method thereof | |
| CN109411675B (en) | Nickel-cobalt-manganese/nickel-cobalt-aluminum acid lithium battery, functional diaphragm for same and production process of diaphragm | |
| CN117423957A (en) | Ceramic microsphere, diaphragm containing ceramic microsphere and lithium ion battery containing diaphragm | |
| KR101473394B1 (en) | Separator for adsorbing metal ion and secondary battery comprising same, and method for preparing separator | |
| CN101677139B (en) | Method of preparing gel polymer lithium ion battery | |
| CN115548463B (en) | Semi-solid battery and preparation method thereof | |
| CN111033803A (en) | Microcapsule, separator including the same, and electrochemical device including the separator | |
| CN112652859A (en) | Flame-retardant structure, preparation method thereof and lithium battery structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |