Separator and method for manufacturing the same, battery, and power consumption device

Abstract

The present application discloses a separator and its manufacturing method, a battery and a power consumption device, wherein the coating is formed on at least a portion of the surface of the substrate, the coating comprises composite particles, first inorganic particles and an adhesive, the composite particles form protrusions on the coating surface, the composite particles comprise polyacrylate particles and ion-conducting particles, the ion-conducting particles are between at least two of the polyacrylate particles, and the mass ratio of the first inorganic particles to the ion-conducting particles is 1:0.007-0.06.

Description

Technical Field

[0001] This application belongs to the field of secondary battery technology, and specifically relates to a separator, a method for manufacturing the same, a battery, and a power consumption device.

Background Art

[0002] Since secondary batteries have excellent characteristics such as being lightweight, pollution-free, and having no memory effect, they are widely used in various household appliances and electric vehicles.

[0003] With the continuous development of the new energy industry, the requirements for the use of secondary batteries by customers are increasing. For example, although secondary batteries are designed to have an increasingly high energy density, an increase in the energy density of the battery tends to damage the balance of electrochemical performance or safety performance.

[0004] Therefore, how to simultaneously achieve good cycle performance and safety performance of the battery has become an important challenge in the field of battery design.

Summary of the Invention

[0005] In view of the technical problems in the background art, the purpose of this application is to provide a separator and enable a battery containing the same to simultaneously achieve good cycle performance and safety performance.

[0006] To achieve the above object, according to the first aspect of this application, a separator is provided. This separator is a coating formed on at least a part of the surface of a base material and includes composite particles, first inorganic particles, and an adhesive. The composite particles form protrusions on the coating surface. The composite particles include polyacrylate particles and ion-conductive particles, and there are ion-conductive particles between at least two of the polyacrylate particles. Here, the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06.

[0007] Compared with the prior art, the present application includes at least the beneficial effects described below. By adopting composite particles containing polyacrylate particles and ion-conductive particles in the separator and having ion-conductive particles between at least two polyacrylate particles, adhesion during the high-temperature granulation process of the composite particles can be avoided, the ion-conductive ability of the separator can be improved, the compression rate of the composite particles can be improved, and the adhesion between the separator and the electrode plate can be made relatively appropriate. Compared with adopting polyvinylidene fluoride particles on the conventional separator, the separator coating of the present application includes composite particles, first inorganic particles, and an adhesive. On the one hand, the separator resistance is reduced, and on the other hand, the adhesion between this separator and the electrode plate is made appropriate during the manufacturing and use processes of the battery core. Most importantly, this separator is provided with an appropriate compression rate to ensure that when the cycle expansion force of the battery core increases, the lithium-ion transmission channel is not blocked and the kinetic performance is not deteriorated, thereby enhancing the kinetic performance of the battery. At the same time, the first inorganic particles in the separator coating can improve the high-temperature resistance of the separator, and the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06. The first inorganic particles and the ion-conductive particles in the composite particles can form a penetrating passage, which is beneficial for the transmission of lithium ions in the electrolyte, that is, to improve the ion electrical conductivity of the separator. Also, when the battery undergoes thermal runaway and high temperature occurs, the protrusions formed on the coating surface by the composite particles can form a large-area adhesive film structure to reduce or block the ion transmission channel, and can mitigate the heat propagation of the battery, thereby effectively improving the cycle performance and high-temperature safety performance of the battery.

[0008] In some embodiments of the present application, based on the mass of the coating, the content of the first inorganic particles is 50% - 70%, preferably 55% - 65%. Thereby, on the one hand, the high-temperature resistance of the separator can be improved, and on the other hand, it is beneficial for forming a penetrating passage with the ion-conductive particles in the composite particles, thereby improving the ion electrical conductivity of the separator.

[0009] In some embodiments of the present application, based on the mass of the coating, the content of the ion-conductive particles is 0.5% - 3%, preferably 0.6% - 1.2%. Thereby, the ionic conductivity of the separator can be improved.

[0010] In some embodiments of the present application, the dielectric constant of the ion-conductive particles is 5 or more, preferably 10 or more. Thereby, the ionic conductivity of the separator can be improved.

[0011] In some embodiments of the present application, the ion-conductive particles include at least one of second inorganic particles and organic-inorganic hybrid composite particles. Thereby, the ionic conductivity of the separator can be improved.

[0012] In some embodiments of the present application, the second inorganic particles are BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3 (PLZT), PB(Mg3Nb 2 / 3 )O3 - PbTiO3 (PMN - PT), HfO2, SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiC, AlO(OH), Al2O3·H2O, Li3PO4, Li x Ti y (PO4)3, γ - AlOOH, BaSO4, Mg(OH)2, SiO2, SrTiO3, at least one of BaTiO3 and MgF2. Thereby, the ionic conductivity of the separator can be improved.

[0013] In some embodiments of the present application, the composite particles include ion-conductive particles in the form of primary particles.

[0014] In some embodiments of the present application, the ratio of the Dv50 of the first inorganic particles to the Dv50 of the ionic conductive particles in the primary particle form is 0.5 - 200:1, preferably 1 - 4:1. Thereby, the ionic conductivity of the separator can be improved.

[0015] In some embodiments of the present application, the Dv50 of the first inorganic particles is 0.5 μm - 2 μm, preferably 1 μm - 2 μm. Thereby, the ionic conductivity of the separator can be improved.

[0016] In some embodiments of the present application, the mass ratio of the composite particles to the first inorganic particles is (5 - 30):(50 - 70). Thereby, the kinetic performance of the battery can be improved.

[0017] In some embodiments of the present application, the Dv50 of the composite particles is larger than the Dv50 of the first inorganic particles. Thereby, it is advantageous to form a protrusion structure on the separator coating surface, thereby improving the kinetic performance of the battery core.

[0018] In some embodiments of the present application, the Dv50 of the composite particles is ≧ 2.5 μm, preferably 2.5 μm - 10 μm, more preferably 3 μm - 8 μm. Thereby, it is advantageous to form a protrusion structure on the coating surface, thereby improving the kinetic performance of the battery core.

[0019] In some embodiments of the present application, the composite particles include a first aggregate, and the first aggregate includes at least two of the ionic conductive particles. Thereby, the kinetic performance of the battery can be enhanced.

[0020] In some embodiments of the present application, 0.01 μm ≦ Dv50 of the first aggregate ≦ Dv10 of the composite particles. Thereby, the compression ratio of the separator can be increased.

[0021] In some embodiments of the present application, the Dv50 of the ion-conductive particles in the form of primary particles is 0.01 μm - 1 μm, preferably 0.5 μm - 1 μm. Thereby, it can be ensured that the composite particles do not fuse in the manufacturing process to block the separator ion transport channels.

[0022] In some embodiments of the present application, the composite particles include a second aggregate, and the second aggregate includes at least two of the polyacrylate particles.

[0023] In some embodiments of the present application, the Dv50 of the second aggregate is 0.3 μm - 5 μm, preferably 1 μm - 2 μm.

[0024] In some embodiments of the present application, the polyacrylate particles include polyacrylate particles in the form of primary particles and / or polyacrylate particles in the form of secondary particles.

[0025] In some embodiments of the present application, the Dv50 of the polyacrylate particles in the form of primary particles is 50 nm - 400 nm, preferably 100 nm - 200 nm. Thereby, the ion conduction ability of the entire separator coating can be enhanced, the separator resistance can be reduced, and the kinetic performance of the battery core can be enhanced.

[0026] In some embodiments of the present application, the Dv50 of the polyacrylate particles in the form of secondary particles is 2 μm - 15 μm, preferably 5 μm - 8 μm. Thereby, a buffer space for releasing the stress between the electrode plates can be provided, and it can be prevented that the bending angle of the wound battery core breaks due to stress accumulation.

[0027] In some embodiments of the present application, the content of the ion-conductive particles in the composite particles is 1 wt% - 50 wt%, optionally 1 wt% - 40 wt%, and further optionally 2 wt% - 15 wt%. Thereby, the separator is provided with an appropriate compression ratio.

[0028] In some embodiments of the present application, the height of both sides of the protrusion is 15 μm - 60 μm. Thereby, while improving the safety of the battery, the kinetic performance of the battery core can be improved.

[0029] In some embodiments of the present application, the surface of the protrusion has the first aggregate. Thereby, the kinetic performance of the battery can be improved.

[0030] In some embodiments of the present application, the adhesive includes a linear copolymer having a hydroxyl group and a carboxylate. Thereby, it is advantageous to form a continuous bridge penetrating between the first inorganic particles and the ion-conductive particles in the composite particles, thereby improving the ion electrical conductivity of the separator.

[0031] In some embodiments of the present application, the adhesive includes a linear copolymer having a hydroxyl group, a carboxylate, an amide group, and an epoxy group. Thereby, it is advantageous to form a continuous bridge penetrating between the first inorganic particles and the ion-conductive particles in the composite particles, thereby improving the ion electrical conductivity of the separator.

[0032] In some embodiments of the present application, the linear copolymer includes polymerization products of various monomers as follows, that is, (1) a first type of monomer including at least one of acrylic acid, methacrylic acid, methyl methacrylate, tert-butyl methacrylate, isobornyl methacrylate, methylolacrylamide, acrylamide, styrene, and acrylonitrile, and (2) A second monomer containing at least one of ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, decyl acrylate, cyclohexyl acrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-hexyl methacrylate, tridecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, ethylene urea ethyl methacrylate, dicyclopentenyl oxyethyl methacrylate, tetrahydrofuryl methacrylate, trifluoroethyl methacrylate, ethylene urea ethyl methacrylate, acrylic methacrylate, dicyclopentenyl oxyethyl methacrylate, tetrahydrofuryl methacrylate and trifluoroethyl methacrylate, (3) A third monomer containing at least one of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, γ-methacryloxypropyltrimethoxysilane, N-methylolacrylamide, N-butoxymethyl (meth)acrylamide, diacetoneacrylamide, ethyl acetoacetate methacrylate, divinylbenzene and an epoxy resin with an epoxy value of 0.35 to 0.50, (4) A fourth monomer containing at least one of polyvinyl alcohol, polypropylene alcohol, polypropylene glycol, polyethylene glycol and polyvinyl alcohol.

[0033] Thereby, the linear copolymer having the above monomers can improve the coating yield of the substrate by providing good wettability on the substrate for the adhesive, enhance the coating density, and more importantly, enhance the adhesion between the first inorganic particles and the composite particles and the substrate, greatly enhance the heat shrinkage performance of the separator, thereby enhancing the safety performance of the battery core, and a chemical reaction can occur between the particle material in the coating, thereby generating an appropriate dense structure and further improving the safety of the separator. Further, such three-dimensional interaction allows lithium ions to pass through the transmission channel, increases the ionic conductivity of the separator, and enhances the kinetic performance of the battery core.

[0034] In some embodiments of the present application, the mass ratio of the composite particles to the adhesive is (80 - 90):(5 - 20), preferably (85 - 90):(8 - 15). Thereby, the cycle performance and safety performance of the battery can be improved.

[0035] In some embodiments of the present application, the coating further includes organic particles, and the organic particles include at least one of polytetrafluoroethylene particles, polychlorotrifluoroethylene particles, polyvinyl fluoride particles, polyvinylidene fluoride particles, polyethylene particles, polypropylene particles, polyacrylonitrile particles, polyethylene oxide particles, copolymer particles of fluorine-containing alkenyl monomer units and vinyl monomer units, copolymer particles of fluorine-containing alkenyl monomer units and acrylic acid-based monomer units, copolymer particles of fluorine-containing alkenyl monomer units and acrylate-based monomer units, and modified compound particles of the above homopolymers or copolymers. The organic particles and the composite particles form the protrusions on the coating surface. Thereby, the cycle performance and safety performance of the battery can be improved.

[0036] In some embodiments of the present application, the organic particles form a third aggregate.

[0037] In some embodiments of the present application, the Dv50 of the third aggregate is 5 μm - 30 μm, preferably 5 μm - 12 μm.

[0038] In some embodiments of the present application, the third aggregate contains organic particles in the form of primary particles, and there is a gap between two adjacent organic particles. Thereby, the ionic conductivity of the separator can be improved.

[0039] In some embodiments of the present application, the Dv50 of the organic particles in the form of primary particles is 50 nm - 400 nm, preferably 100 nm - 200 nm.

[0040] In some embodiments of the present application, the mass ratio of the composite particles to the organic particles is (20 - 90):(0 - 70), preferably (45 - 90):(0 - 45). Thereby, the cost of the battery can be reduced while improving its safety performance and cycle performance.

[0041] According to a second aspect of the present application, a method for manufacturing a separator is provided. This method includes: (1) providing a substrate; and (2) forming a coating containing composite particles, first inorganic particles, and an adhesive on at least a part of the surface of the substrate, wherein the composite particles form protrusions on the surface of the coating, the composite particles include polyacrylate particles and ion-conductive particles, and there are ion-conductive particles between at least two of the polyacrylate particles, and here, the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06.

[0042] Thereby, this separator has excellent ionic conductivity and compressibility, and there is appropriate adhesiveness between this separator and the electrode plate, thereby improving the cycle performance of the battery while enhancing its safety performance.

[0043] According to a third aspect of the present application, a battery is provided, which includes a separator according to the first aspect of the present application, or a separator manufactured based on the method of the second aspect of the present application. Since the battery of the present application includes the separator according to the above of the present application or the separator manufactured by the above method, it has excellent safety performance and cycle performance.

[0044] According to a fourth aspect of the present application, a power consumption device is provided, which includes a battery according to the third aspect of the present application, and the battery is used to provide electrical energy. Since the power consumption device of the present application includes the battery according to the above of the present application, it has at least the same advantages as the above battery.

Brief Description of the Drawings

[0045] To more clearly illustrate the technical solution of the present application, the following briefly introduces the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can also obtain other drawings based on these drawings on the premise of not paying creative labor.

[0046]

Figure 1

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Figure 9

Embodiments for Carrying Out the Invention

[0047] Hereinafter, the present application will be described in more detail while combining the embodiments for carrying out the invention. It should be understood that these embodiments for carrying out the invention are only for explaining the present application and not for limiting the scope of the present application.

[0048] For the sake of simplicity and clarity, this specification specifically discloses only several numerical ranges. However, any lower limit and any upper limit can form a range that is not clearly described in combination, any lower limit and other lower limits can form a range that is not clearly described in combination, and similarly any upper limit and any other upper limit can form a range that is not clearly described in combination. In addition, each individually disclosed point or single numerical value itself can form a range that is not clearly described in combination with any other point or single numerical value as a lower limit or upper limit or in combination with other lower limits or upper limits.

[0049] In the description of this specification, unless otherwise specified, the term "or" is inclusive. That is, the phrase "A or B" represents "A, B, or both A and B". More specifically, any of the conditions where A is true (or exists) and B is false (or does not exist), where A is false (or does not exist) but B is true (or exists), and where both A and B are true (or exist) satisfy "A or B".

[0050] In the description of this specification, it should be noted that, unless otherwise specified, "above" and "below" include this number, and "plural" in "one or more" means two or more.

[0051] Unless otherwise specified, the terms used in this application have the well-known meanings generally understood by those skilled in the art. Unless otherwise specified, the numerical values of each parameter mentioned in this application can be measured using various commonly used measurement methods in the art (for example, it can be tested according to the methods given in the examples of this application).

[0052] The examples of this application provide a separator. Referring to FIG. 1, it is a coating formed on at least a part of the surface of a substrate and comprising composite particles, first inorganic particles, and an adhesive, wherein the composite particles form protrusions on the coating surface, the composite particles include polyacrylate particles and ion-conductive particles, and there are ion-conductive particles between at least two of the polyacrylate particles, and the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06.

[0053] It should be noted that "the coating is formed on at least a part of the surface of the substrate" should be understood as the coating being in direct contact with the surface of the substrate, that is, the so-called "direct contact", or there is another layer between the substrate surface and the coating, that is, the so-called "indirect contact". At the same time, "there are ion-conductive particles between at least two of the polyacrylate particles and the composite particles form protrusions on the coating surface" means that the separator is cut along its thickness direction, and then a scanning electron microscope (SEM) is used to scan the cross-section of the separator coating. From the SEM image, it can be seen that the composite particles include polyacrylate particles and ion-conductive particles, there are ion-conductive particles between some of the polyacrylate particles, and the composite particles form protrusions on the coating surface.

[0054] Specifically, the test is performed using a ZEISS Sigma300 scanning electron microscope, and the test is carried out according to the following steps of operation. First, the separator to be tested is cut into a 6 mm × 6 mm sample to be tested, the sample to be tested is sandwiched using two pieces of conductive heat-conducting copper foil, the space between the sample to be tested and the copper foil is adhered and fixed with double-sided tape, crimped for 1 hour using a flat iron block weighing 400 g to make the gap between the sample to be tested and the copper foil as small as possible, then cut with scissors so that the edges are aligned, pasted onto a sample stage with conductive adhesive, and the sample should protrude slightly beyond the edge of the sample stage. Then the sample stage is mounted on the sample holder, locked and fixed, the power of the IB-19500CP argon ion cross-section polisher is turned on and evacuated to 10 Pa -4 Pa, the argon gas flow rate is set to 0.15 MPa, the voltage is set to 8 KV, the polishing time is set to 2 hours, the sample stage is adjusted to the rocking mode and polishing begins. After the polishing is completed, an ion-polished cross-sectional morphology (CP) image of the sample to be tested is obtained using a ZEISS Sigma300 scanning electron microscope.

[0055] While not wishing to be bound by any theory, the inventors have discovered through extensive research the following. The separator coating of the present application contains composite particles, first inorganic particles, and an adhesive. The composite particles and the first inorganic particles are adhered to a substrate via the adhesive. The composite particles include polyacrylate particles and ion-conductive particles, and there are ion-conductive particles between at least two polyacrylate particles in the composite particles. On the one hand, due to the presence of the ion-conductive particles in the composite particles, adhesion does not occur during the high-temperature treatment of the granulation process between the polyacrylate particles. The polyacrylate particles after adhesion, when used in the separator coating, cause ion transmission to be obstructed, thereby reducing the ion-conductive ability of the separator. On the other hand, since the polyacrylate particles have a relatively low compressibility, when used alone in the separator coating, they are likely to block the holes of the separator and then block the anode surface under the action of pressure, thereby reducing ion conduction and the kinetic performance of the battery. However, by installing ion-conductive particles between the polyacrylate particles, its compressibility can be improved, and it can be guaranteed that the kinetic performance of the separator and the anode is not affected by this composite particle, thereby enhancing the kinetic performance of the battery. At the same time, the first inorganic particles in the separator coating can improve the high-temperature resistance of the separator, and the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06. The first inorganic particles and the ion-conductive particles in the composite particles can form a penetrating passage, which is beneficial for the transmission of lithium ions in the electrolyte, that is, it improves the ion conductivity of the separator. Further, the composite particles form protrusions on the coating surface, and the separator contacts the electrode plate through these protrusions. On the one hand, during the winding process, the protrusions provide an appropriate space to release stress and prevent the fracture of the electrode plate, improving safety. On the other hand, a gap is left between the separator and the electrode plate, which is beneficial for the flow and infiltration of the electrolyte and improves the kinetic performance of the battery core.With the combined action of the above conditions, an appropriate adhesive force is provided between the separator and the electrode plate, thereby improving the kinetic performance of the battery. When the battery is in high-temperature operation, the protrusions can form a large-area adhesive film structure to reduce or block the ion transmission channels, and can mitigate the heat propagation of the battery, thereby effectively improving the cycle performance and safety performance of the battery at high temperatures.

[0056] As a result of intensive research, the inventor of the present invention has discovered that when the separator of the present application satisfies the above conditions and further selectively satisfies one or some of the following conditions, the performance of the battery can be further improved.

[0057] In some embodiments, the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06, such as 1:0.008 - 0.06, 1:0.009 - 0.06, 1:0.01 - 0.06, 1:0.011 - 0.06, 1:0.013 - 0.06, 1:0.015 - 0.06, 1:0.017 - 0.06, 1:0.02 - 0.06, 1:0.025 - 0.06, 1:0.03 - 0.06, 1:0.035 - 0.06, 1:0.04 - 0.06, 1:0.045 - 0.06, 1:0.05 - 0.06, 1:0.055 - 0.06, etc. Thereby, on the one hand, the high-temperature resistance of the separator can be improved, and on the other hand, it is advantageous for the ion-conductive particles and the first inorganic particles in the composite particles to form a penetrating passage, thereby improving the ion and electrical conductivity of the separator.

[0058] In some embodiments, based on the mass of the coating, the content of the first inorganic particles is 50% - 70%, for example 51% - 70%, 52% - 70%, 53% - 70%, 54% - 70%, 55% - 70%, 55% - 69%, 55% - 68%, 55% - 67%, 55% - 66%, 55% - 65%, 56% - 64%, 57% - 63%, 58% - 62%, 59% - 61%, 59% - 60%, etc. Thereby, the high-temperature resistance and ionic conductivity of the separator can be improved simultaneously. In some other embodiments of the present application, based on the mass of the coating, the content of the first inorganic particles is 55% - 65%.

[0059] In some embodiments, the first inorganic particles may include one or more of boehmite (γ - AlOOH), aluminum oxide (Al2O3), barium sulfate (BaSO4), magnesium oxide (MgO), magnesium hydroxide (Mg(OH)2), silicon dioxide (SiO2), tin dioxide (SnO2), titanium dioxide (TiO2), calcium oxide (CaO), zinc oxide (ZnO), zirconium oxide (ZrO2), yttrium oxide (Y2O3), nickel oxide (NiO), cerium oxide (CeO2), strontium titanate (SrTiO3), barium titanate (BaTiO3), magnesium fluoride (MgF2). For example, the inorganic particles may include one or more of boehmite (γ - AlOOH) and aluminum oxide (Al2O3).

[0060] In some embodiments, based on the mass of the coating, the content of the ion-conductive particles is 0.5% - 3%, for example, 0.5% - 2.8%, 0.5% - 2.5%, 0.5% - 2.3%, 0.5% - 2%, 0.5% - 1.8%, 0.5% - 1.5%, 0.5% - 1.2%, 0.6% - 1.2%, 0.7% - 1.1%, 0.8% - 1%, 0.9% - 1%, etc. Thereby, the ion-conductive particles with this content can form a communication bridge penetrating the first inorganic particles, thereby improving the ionic conductivity of the separator. In some other embodiments of the present application, based on the mass of the coating, the content of the ion-conductive particles is 0.6% - 1.2%.

[0061] In some embodiments, the dielectric constant of the ion-conductive particles is 5 or more. The ion-conductive particles satisfying this dielectric constant can form a passage penetrating the first inorganic particles, and this passage is advantageous for the transmission of lithium ions in the electrolyte, thereby significantly improving the ionic conductivity of the separator. In some other embodiments of the present application, the dielectric constant of the ion-conductive particles is 10 or more. Thereby, the ionic conductivity of the separator can be further improved.

[0062] By way of example, the production of the composite particles of the present application may refer to the following steps.

[0063] (1) Provide a polymer monomer for producing polyacrylate particles, polymerize the polymer monomer to obtain a polyacrylate polymer, (2) Add a solvent and ion-conductive particles to the polyacrylate polymer obtained in step (1), and after stirring, obtain a mixed slurry, (3) Dry the mixed slurry in step (2) to remove the solvent, and then crush and pulverize it to obtain the composite particles described in the present application.

[0064] It should be noted that the polymerization of the polymer monomer may be carried out by adopting polymerization methods generally used in the art. For example, emulsion polymerization or suspension polymerization methods may be adopted for polymerization.

[0065] In some embodiments, in step (1), additives may be further added to the polymerization system of the polymer monomer, such as an emulsifier, for example, sodium dodecyl sulfate, and a polymerization initiator, for example, ammonium persulfate.

[0066] In some embodiments, in step (1), the polymer monomer for producing polyacrylate particles includes at least the following polymer monomers.

[0067] A first polymer monomer having at least one ester bond, optionally one or more of methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, vinyl acetate, trifluoroethyl methacrylate, glycidyl methacrylate or trimethylolpropane triacrylate, and further optionally one or more of methyl methacrylate, lauryl acrylate, lauryl methacrylate or trimethylolpropane triacrylate. A second polymer monomer having at least one cyano bond, optionally one or more of acrylonitrile, methacrylonitrile, ethacrylonitrile, and further optionally one or more of acrylonitrile, methacrylonitrile. A third polymer monomer, which has at least one amide bond and is selectively one or more of acrylamide, N-methylolacrylamide, and N-butoxymethacrylamide, and more selectively one or more of acrylamide and N-methylolacrylamide.

[0068] Thereby, the polyacrylate particles are formed by polymerizing by adopting at least the above three kinds of polymer monomers, and can be provided with appropriate adhesiveness to the electrode plate in the separator, improving the kinetic performance of the battery.

[0069] In some embodiments, the weight ratio of the first polymer monomer, the second polymer monomer, and the third polymer monomer in the formed polyacrylate particles is 1:0 - 0.8:0.05 - 0.75, for example, 1:0.1 - 0.8:0.05 - 0.75, 1:0.1 - 0.7:0.05 - 0.75, 1:0.2 - 0.6:0.05 - 0.75, 1:0.3 - 0.5:0.05 - 0.75, 1:0.3 - 0.4:0.05 - 0.75, 1:0 - 0.8:0.05 - 0.7, 1:0 - 0.8:0.1 - 0.7, 1:0 - 0.8:0.15 - 0.65, 1:0 - 0.8:0.2 - 0.6, 1:0 - 0.8:0.3 - 0.5, 1:0 - 0.8:0.4. Thereby, the kinetic performance of the battery can be improved. In some other embodiments, the weight ratio of the first polymer monomer, the second polymer monomer, and the third polymer monomer in the formed polyacrylate particles is 1:0.1 - 0.6:0.1 - 0.6.

[0070] In some embodiments, the ion-conductive particles include at least one of second inorganic particles and organic-inorganic hybrid composite particles, where the second inorganic particles are BaTiO3, Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3 (PLZT), PB(Mg3Nb 2 / 3)O3-PbTiO3 (PMN-PT), HfO2, SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiC, AlO(OH), Al2O3·H2O, Li3PO4, Li x Ti y contains at least one of (PO4)3, γ-AlOOH, BaSO4, Mg(OH)2, SiO2, SrTiO3, BaTiO3 and MgF2.

[0071] In some embodiments, the organic-inorganic hybrid composite particles contain metal atoms and / or their cations, and organic ligands, and the basic units constituting the organic-inorganic hybrid composite particles are periodically assembled along at least one spatial direction. When the organic-inorganic hybrid composite particles adopt a given composition, the ionic conductivity of the separator can be significantly improved.

[0072] In some embodiments, the organic-inorganic hybrid composite particles are formed by periodically assembling at least one basic unit represented by Formula 1 along at least one spatial direction, In formula 1 of TIFF0007701992000001.tif, M is a cation of one or more metals selected from Zn, Co, Cu, Fe, Cd, Mn, Ag, Rh, Ru, Be, Mg, Al, Sc, Cr, Ni, Y, Ti, Zr, Hf, Li, Na, K, In, Ca, Sr, Pb, lanthanide metals, and actinide metals, and y is a numerical value within the range of 0.1 - 10. For example, y is 0.2 - 10, 0.5 - 10, 0.7 - 10, 1 - 10, 2 - 10, 3 - 10, 4 - 10, 5 - 10, 6 - 10, 7 - 10, 8 - 10, 9 - 10, 9.2 - 10, 9.5 - 10. Optionally, M is a cation of one or more metals selected from Zn, Co, Cu, Fe, Cd, Mn, Mg, Cr, Ni, Y, Na, K. Further optionally, M is a cation of one or more metals selected from Co, Fe, Mn, and Ni. When M is a cation of two or more metals, y represents the number of all metal cations in the basic unit M shown in a single formula 1. By selecting this type of metal ion M, the ion conduction performance of the organic-inorganic hybrid composite particles can be enhanced, and further the ionic conductivity of the separator can be increased.

[0073] In some embodiments, in the organic-inorganic hybrid composite particles of formula (I) above, A is an atom or cation of one or more metal elements selected from Li, Na, K, Rb, Cs, Be, Sr, Zn, Al, Mg, and Ca, and / or one or more molecules selected from H2, O2, H2O, CO2, NH3, CH4, methyl formate, ethyl acetate, and propylene carbonate. z is a numerical value from 0 to 100, for example, 1 - 95, 1.5 - 90, 1.6 - 85, 1.7 - 80, 1.8 - 75, 1.9 - 70, 2 - 65, 2.5 - 60, 3 - 50, 3.5 - 40, 4 - 30, 5 - 20, 6 - 10, etc. Optionally, z is a numerical value from 1.8 to 2. Optionally, A is an atom or cation of one or more metal elements and / or one or more molecules selected from Li, Na, K, Zn, H2O, CO2, NH3, CH4, and methyl formate. Further optionally, A is an atom or cation of one or more metal elements selected from Li, Na, and K. By selecting the A moiety in formula (I), the affinity of the composite particles for the electrolyte can be increased, the liquid retention capacity can be enhanced, and the kinetic performance of the secondary battery can be improved.

[0074] In some embodiments, in the organic-inorganic hybrid composite particles of formula (I) above, L is one or more ligands selected from a cyano group (CN - ), a thiocyanato group (SCN - ), nitriles and their salts, acid radicals, esters, and acid anhydrides. Optionally, L is one or more ligands selected from a cyano group, a thiocyanato group, or a nitrile. Further optionally, L is a cyano group, and / or the nitrile is a linear or branched C2-C 12 alkanedinitrile, a linear or branched C3-C 12 alkanetrinitrile, a linear or branched C4-C 12 alkanetetranitrile, a linear or branched C2-C 12 alkenedinitrile, a linear or branched C3-C 12 alkenetrinitrile, a linear or branched C4-C 12 alkenetetranitrile, a linear or branched C2-C 12Alkynedinitrile, linear or branched C3-C 12 Alkynetricarbonitrile, linear or branched C4-C 12 One or more selected from alkynetetracarbonitrile, and one or more hydrogen atoms in the nitrile are cyano group, nitro group, amino group, aldehyde group, carboxyl group, halogen, C1-C8 alkyl group, C1-C8 hydroxyalkyl group, C1-C8 alkoxy group, C2-C8 alkenyl group, C2-C8 alkynyl group, C3-C 16 Cycloalkyl group, C6-C 20 Aryl group, C6-C 20 Heteroaryl group, or optionally substituted by one or more substituents selected from any combination thereof, x is a numerical value from 1 to 50, for example 2-48, 5-45, 7-42, 10-40, 12-38, 15-35, 17-30, 20-28, 22-25, and optionally x is a numerical value from 3 to 6.5. By selecting the ligand L in formula (I), the ionic conductivity of the organic-inorganic hybrid composite particles can be further increased, the separator resistance value can be reduced, and the kinetic performance of the battery core can be enhanced.

[0075] In some embodiments, the organic-inorganic hybrid composite particles include at least one of (CN)6[FeMn]K2, (CN) 5.7 [Co 0.95 Fe]K 1.8 and (CN) 5.98 [Fe 0.99 Mn]Na 1.99 When the organic-inorganic hybrid composite particles adopt a given type, the safety performance and cycle performance of the battery can be further improved.

[0076] In some embodiments, in the separator of the present application, the composite particles include ion-conductive particles in the form of primary particles. Further, the ratio of Dv50 of the first inorganic particles to Dv50 of the ion-conductive particles in the form of primary particles is 0.5-200:1, for example, 1-200:1, 2-200:1, 3-200:1, 4-200:1, 5-175:1, 10-150:1, 20-125:1, 30-100:1, 40-100:1, 50-100:1, 60-100:1, 70-100:1, 80-100:1, 90-100:1, etc. By compounding the first inorganic particles satisfying this particle size ratio with the composite particles having ion-conductive particles in this particle size range, the ionic conductivity of the separator can be significantly improved. In some other embodiments, the ratio of Dv50 of the first inorganic particles to Dv50 of the ion-conductive particles is 1-4:1.

[0077] In some embodiments, in the separator of the present application, Dv50 of the first inorganic particles is 0.5 μm - 2 μm, for example, 0.5 μm - 1.8 μm, 1 μm - 2 μm, 1 μm - 1.8 μm, 1.2 μm - 1.8 μm, 1.4 μm - 1.6 μm, etc. The first inorganic particles have a good inhibitory effect on the heat shrinkage of the substrate, thereby improving the thermal stability of the separator. On the one hand, the first inorganic particles satisfying this particle size range can be uniformly dispersed in the separator coating, thereby improving the thermal stability of the separator. On the other hand, the first inorganic particles satisfying this particle size range can form a conductive path with the ion-conductive particles in the composite particles, thereby significantly improving the ionic conductivity of the separator.

[0078] In some embodiments, the mass ratio of the composite particles to the first inorganic particles is (5 - 30):(50 - 70), for example (5 - 30):(52 - 68), (5 - 30):(55 - 65), (5 - 30):(57 - 62), (5 - 30):(60 - 62), (7 - 28):(50 - 70), (10 - 25):(50 - 70), (12 - 22):(50 - 70), (15 - 20):(50 - 70), (15 - 18):(50 - 70). Thereby, on the one hand, the adhesion between the separator and the electrode plate can be made appropriate, and the kinetic performance of the battery can be improved. On the other hand, the high-temperature resistance and ion conductivity of the separator can be improved, thereby effectively improving the cycle performance and safety performance at high temperature of the battery.

[0079] In some embodiments, the Dv50 of the composite particles is greater than the Dv50 of the first inorganic particles. Thereby, not only can appropriate adhesion between the separator and the electrode plate be provided, but it is also advantageous for forming protrusions on the coating surface, thereby improving the safety of the battery and simultaneously improving the kinetic performance of the battery core.

[0080] In some embodiments, in the separator of the present application, the Dv50 of the composite particles is ≧ 2.5 μm, for example 2.5 μm - 10 μm, 2.5 μm - 8 μm, 2.5 μm - 6 μm, 2.5 μm - 5 μm, 2.5 μm - 4 μm, 2.5 μm - 3 μm, etc. Thereby, on the one hand, the composite particles satisfying this Dv50 range can provide appropriate adhesion between the separator coating and the electrode plate. On the other hand, it is advantageous for forming a protrusion structure on the coating surface, thereby improving the kinetic performance of the battery core.

[0081] In some embodiments, in the separator of the present application, there are first aggregates among the polyacrylate particles, and the first aggregates contain at least two ion-conductive particles. Thereby, on the one hand, it prevents the composite particles from becoming too flexible, thereby ensuring that when the battery expands or receives a relatively large external force, the interaction between the composite particles and the electrode plate and between the composite particles and the substrate is appropriate, thereby improving the kinetic performance of the battery. On the other hand, it can be ensured that the composite particles do not fuse in the manufacturing process to block the ion transport channels, and when there are first aggregates formed by ion-conductive particles inside or on the surface of the composite particles, at a high temperature, for example, ≥45 °C and a stress state ≥0.4 MPa, it is guaranteed that the substantially spherical body of the composite particles does not soften and collapse, thereby ensuring that the interaction between the composite particles and the electrode plate and between the composite particles and the substrate is appropriate, thereby suppressing the deterioration of the cycle performance of the battery and further improving the kinetic performance of the battery.

[0082] In some embodiments, 0.01 μm ≤ Dv50 of the first aggregates ≤ Dv10 of the composite particles. Thereby, the compression rate of the separator can be increased.

[0083] In some embodiments, Dv50 of the ion-conductive particles in the form of primary particles is 0.01 μm - 1 μm, such as 0.01 μm - 0.8 μm, 0.05 μm - 1 μm, 0.1 μm - 1 μm, 0.2 μm - 1 μm, 0.3 μm - 1 μm, 0.4 μm - 1 μm, 0.5 μm - 1 μm, 0.6 μm - 1 μm, 0.7 μm - 1 μm, 0.8 μm - 1 μm, 0.9 μm - 1 μm, etc. Thereby, the ion-conductive particles satisfying this Dv50 can endow the separator with an appropriate compression rate, thereby enhancing the kinetic performance of the battery. In some other embodiments, Dv50 of the ion-conductive particles in the form of primary particles is 0.5 μm - 1 μm. Thereby, the kinetic performance of the battery can be enhanced.

[0084] It should be noted that the primary particles and secondary particles have meanings known in the art. The primary particles refer to particles that do not form an aggregated state. The secondary particles refer to particles in an aggregated state formed by the aggregation of two or more primary particles. The primary particles and secondary particles can be easily distinguished by a scanning electron microscope (SEM) image.

[0085] In some embodiments, in the separator of the present application, the composite particles include a second aggregate, and the second aggregate includes at least two of the polyacrylate particles. Thereby, the composite particles are prevented from becoming too flexible, and thereby when the battery expands or receives a relatively large external force, the interaction between the composite particles and the electrode plate and between the composite particles and the separator substrate is appropriate, thereby improving the dynamic performance of the battery. Further, the Dv50 of the second aggregate is 0.3 μm - 5 μm, such as 0.5 μm - 5 μm, 0.7 μm - 4.5 μm, 1 μm - 4 μm, 1.3 μm - 3.5 μm, 1.5 μm - 3.2 μm, 1.7 μm - 3 μm, 2 μm - 2.8 μm, 2 μm - 2.5 μm, 5 μm - 10 μm, 5 μm - 9 μm, 5 μm - 8 μm, 5 μm - 7 μm, 5 μm - 6 μm, etc. In some other embodiments, the Dv50 of the second aggregate is 1 μm - 2 μm.

[0086] In some embodiments, in the composite particles of the present application, the polyacrylate particles include polyacrylate particles in the form of primary particles and / or polyacrylate particles in the form of secondary particles. Here, the Dv50 of the polyacrylate particles in the form of primary particles is 50 nm - 400 nm, for example, 50 nm - 375 nm, 75 nm - 375 nm, 100 nm - 350 nm, 125 nm - 325 nm, 150 nm - 300 nm, 175 nm - 275 nm, 200 nm - 250 nm, 200 nm - 225 nm, etc. In some other embodiments, the Dv50 of the polyacrylate particles in the form of primary particles is 100 nm - 200 nm. The Dv50 of the polyacrylate particles in the form of secondary particles is 2 μm - 15 μm, for example, 3 μm - 15 μm, 4 μm - 12 μm, 5 μm - 10 μm, 5 μm - 8 μm, 5 μm - 7 μm, 5 μm - 6 μm, etc.

[0087] In some embodiments, the content of the ion-conductive particles in the composite particles is 1 wt% - 50 wt%, for example, 1 wt% - 48 wt%, 1 wt% - 45 wt%, 1 wt% - 40 wt%, 1 wt% - 35 wt%, 1 wt% - 30 wt%, 1 wt% - 25 wt%, 1 wt% - 20 wt%, 1 wt% - 15 wt%, 2 wt% - 15 wt%, 3 wt% - 15 wt%, 4 wt% - 15 wt%, 5 wt% - 15 wt%, 7 wt% - 15 wt%, 10 wt% - 15 wt%, 12 wt% - 15 wt%, etc. Thereby, the content of the ion-conductive particles in the composite particles is controlled within the above content range. On the one hand, adhesion does not occur during the high-temperature treatment of the granulation process between the polyacrylate particles, improving the ion conduction ability of the separator. On the other hand, the adhesion of the polyacrylate particles can be appropriately reduced while improving its compression rate, thereby enhancing the kinetic performance of the battery. On the other hand, it is advantageous for forming a passage penetrating the first inorganic particles, thereby improving the ion and electrical conductivity of the separator.

[0088] In some embodiments, referring to FIG. 2, protrusions (which include composite particles) are formed on the separator coating surface of the present application, and the height of both sides of this protrusion is 15 μm - 60 μm, for example, 15 μm - 58 μm, 16 μm - 56 μm, 18 μm - 55 μm, 20 μm - 52 μm, 22 μm - 40 μm, 25 μm - 40 μm, 25 μm - 38 μm, 25 μm - 36 μm, 28 μm - 35 μm, 30 μm - 32 μm, etc. Thereby, the protrusions within this height range can, on the one hand, provide an appropriate space between the separator and the electrode plate to release stress, prevent fracture during the electrode plate winding process, and improve safety. On the other hand, an appropriate gap is left between the separator and the electrode plate, which is beneficial for the flow and infiltration of the electrolyte and improves the kinetic performance of the battery core. Furthermore, the surface of the protrusion has a first aggregate. Thereby, this protrusion can provide appropriate adhesiveness between the separator and the electrode plate, thereby enhancing the kinetic performance of the battery.

[0089] Specifically, coatings are formed on both of the two opposing surfaces of the substrate, and the sum of the heights of the protrusions on the coatings on both sides is the height of both sides of the protrusion. The test method for the height of both sides of the protrusion includes the following. Referring to FIG. 3, first, after laminating the negative electrode plate, the separator, and the positive electrode plate in sequence on the battery core and then winding (the outermost layer of the battery core ends with the convex surface of the positive electrode plate), and then using a CT device (ZEISS - 1500) to scan at a position 15 ± 1 mm downward from the edge of the negative electrode plate at the bending angle of the wound battery core. In the obtained CT image, sampling is performed along the horizontal & oblique angle (30 - 45°), a line is drawn in the direction with the largest gap, the inner five - fold sampling position is from the convex surface of the innermost positive electrode plate to the convex surface of the fifth - layer positive electrode plate, the average value of four - fold is taken, the sampling position after six - fold is from the convex surface of the inner - layer positive electrode plate to the convex surface of the outer - layer positive electrode plate, and values are taken every five - fold.

[0090] The average value of the inner five - layer gap = [CT measurement distance - 4 * thickness of the negative electrode plate after cold pressing * (1 + rebound rate of the negative electrode plate) - 4 * thickness of the positive electrode plate after cold pressing * (1 + rebound rate of the positive electrode plate) - 8 * thickness of the separator] / 8. The average gap value after the 6th to 10th layers = [CT measurement distance - 5 * thickness of the negative electrode plate after cold pressing * (1 + rebound rate of the negative electrode plate) - 5 * thickness of the positive electrode plate after cold pressing * (1 + rebound rate of the positive electrode plate) - 10 * thickness of the separator] / 10, where the rebound rate of the negative electrode plate = (thickness of the negative electrode plate before putting it into the case - thickness of the negative electrode plate after cold pressing) / thickness of the negative electrode plate after cold pressing, the rebound rate of the positive electrode plate = (thickness of the positive electrode plate before putting it into the case - thickness of the positive electrode plate after cold pressing) / thickness of the positive electrode plate after cold pressing, the height on both sides of the separator protrusion = (average gap value of the 5th inner layer + average gap value after the 6th to 10th layers) / 2.

[0091] In some embodiments, the adhesive in the separator of the present application may include a linear copolymer having a hydroxyl group and a carboxylate salt. The carboxylate salt portion in the linear copolymer can be bonded to the first inorganic particles and the composite particles by chemical interaction forces (such as ionic bonds, hydrogen bonds, etc.), improving the heat resistance of the separator and the kinetic performance of the battery core. Also, the hydroxyl group in the linear copolymer can improve the adhesion between the coating and the substrate and avoid peeling. Specifically, for the linear copolymer contained in the adhesive, the hydroxyl group contained therein generates a hydrogen bonding effect with the composite particles and the first inorganic particles, and the nitrogen and oxygen atoms contained in the linear copolymer generate a hydrogen bonding effect with the composite particles and the first inorganic particles, etc. The carboxylate salt portion (including lithium ions, sodium ions, etc.) contained in the linear copolymer forms ionic bonds with the composite particles and the first inorganic particles, etc. Thereby, the separator of the present application realizes beneficial effects of heat resistance, foreign object puncture resistance, good electrolyte infiltration, and low resistance by selecting appropriate particle materials and adhesives. Furthermore, such a separator is used in a battery and can improve the safety and cycle performance of the battery.

[0092] In some embodiments, the adhesive in the separator of the present application may include a linear copolymer containing a hydroxyl group, a carboxylate, an amide group, and an epoxy group. The epoxy group and the amide group contained in the linear copolymer can further improve the safety performance of the separator. Specifically, the amide group can generate a hydrogen bonding action with composite particles, the first inorganic particles, etc. The nitrogen and oxygen atoms contained in the linear copolymer generate a hydrogen bonding action with the hydroxyl group, amide group, carboxyl group, pyrrolidone group, etc. of the first inorganic particle and the composite particle, thereby improving the heat resistance of the separator.

[0093] In addition, the hydroxyl group or amide group contained in the adhesive undergoes a nucleophilic substitution reaction with the ester group, carboxyl group, sulfonylamide group, or pyrrolidone group of the composite particles, and a nucleophilic addition reaction also occurs between the epoxy group in the composite particles and the carboxyl group or amide group contained in the adhesive.

[0094] In some embodiments, the carboxylate in the above adhesive may be lithium carboxylate. Selecting lithium carboxylate can effectively form a relatively strong ionic bonding action with the composite particles and the first inorganic particles, further enhancing the temperature resistance performance of the entire coating. Especially when the temperature is higher than 130 °C, it has relatively high temperature resistance, and the separator does not shrink. When a large amount of heat is generated by piercing a needle, the separator does not shrink and does not cause large-area contact between the positive and negative electrodes, so the needle penetration depth is significantly increased. Such an effect penetrates the coating, the base film, and the coating interface. Moreover, such an effect has a very strong polarity, and due to the presence of lithium ions, it accelerates the infiltration and diffusion of the electrolyte and improves the kinetic performance of the battery core.

[0095] In some embodiments, in the separator of the present application, the linear copolymer includes polymerization products of various monomers as follows.

[0096] (1) A first monomer, wherein the first monomer comprises at least one of acrylic acid, methacrylic acid, methyl methacrylate, tert-butyl methacrylate, isobornyl methacrylate, methylolacrylamide, acrylamide, styrene and acrylonitrile. Optionally, the first monomer comprises at least one of styrene, methacrylic acid, acrylamide, acrylic acid and acrylonitrile. (2) A second monomer, wherein the second monomer comprises at least one of ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, decyl acrylate, cyclohexyl acrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-hexyl methacrylate, tridecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, ethylene urea ethyl methacrylate, dicyclopentenyl oxyethyl methacrylate, tetrahydrofuryl methacrylate, trifluoroethyl methacrylate, ethylene urea ethyl methacrylate, methacrylic acid acrylate, dicyclopentenyl oxyethyl methacrylate, tetrahydrofuryl methacrylate and trifluoroethyl methacrylate, and is trifluoroethyl methacrylate. Optionally, the second monomer comprises at least one of n-butyl acrylate and n-hexyl methacrylate. (3) A third monomer, wherein the third monomer includes at least one of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, γ-methacryloxypropyltrimethoxysilane, N-methylolacrylamide, N-butoxymethyl (meth) acrylamide, diacetoneacrylamide, ethyl acetoacetate methacrylate, divinylbenzene, and an epoxy resin with an epoxy value of 0.35 to 0.50. Optionally, the third monomer includes at least one of 2-hydroxyethyl methacrylate, an epoxy resin with an epoxy value of 0.35 to 0.50, and divinylbenzene. (4) A fourth monomer, wherein the fourth monomer includes at least one of polyvinyl alcohol, polypropylene alcohol, polypropylene glycol, polyethylene glycol, and polyvinyl alcohol. Optionally, the fourth monomer is polyvinyl alcohol. Here, the degree of alcoholysis of the fourth monomer ≥ 85%, and the average degree of polymerization is from 400 to 2000. Optionally, the degree of alcoholysis of the fourth monomer ≥ 88%, and the average degree of polymerization is from 500 to 1600.

[0097] It should be noted that in this application, the term "degree of alcoholysis" refers to the percentage of hydroxyl groups in the product obtained after alcoholysis in the original group, and the unit is mole fraction %. For example, if there are 100 original groups (ester groups) and 60 hydroxyl groups after alcoholysis, the degree of alcoholysis is 60%.

[0098] It should be noted that in this application, the term "average degree of polymerization" refers to the fact that the polymer is composed of homologous polymer molecules with different degrees of polymerization, and its degree of polymerization has the meaning of statistical average. There are two most commonly used methods to represent the average degree of polymerization. That is, the degree of polymerization obtained by the average of the number of molecules, which is called the number-average degree of polymerization, and the degree of polymerization obtained by the average of the weight, which is called the weight-average degree of polymerization. The "average degree of polymerization" described in this application is the number-average degree of polymerization.

[0099] Thereby, the linear copolymer having the above monomers can improve the coating yield of the substrate by providing good wettability on the substrate in the adhesive, enhance the coating density, and more importantly, enhance the adhesion between the first inorganic particles and the composite particles and the substrate, and significantly enhance the heat shrinkage performance of the separator, thereby enhancing the safety performance of the battery core. And a chemical reaction can occur between the particle material in the coating, thereby generating an appropriate dense structure and further improving the safety of the separator. In addition, such a three-dimensional interaction allows lithium ions to pass through the transmission channel, increases the ionic conductivity of the separator, and enhances the kinetic performance of the battery core.

[0100] In some embodiments, in the separator of the present application, for the above linear copolymer, after polymerizing the first monomer, the second monomer, the third monomer, and the fourth monomer, it is necessary to add a pH adjuster to adjust the pH of the system to 5-7. The pH adjuster includes at least one of lithium hydroxide, calcium hydroxide, sodium hydroxide, and aqueous ammonia. In some other embodiments, the pH adjuster includes lithium hydroxide. By adding a pH adjuster after polymerizing the monomers to adjust the pH of the system, it is advantageous for the dispersion of the first inorganic particles in the adhesive, thereby further improving the coating interface and improving the cycle performance and safety performance of the battery core. In particular, in some embodiments, this pH adjuster is lithium hydroxide. Without being bound by any theory, the inventors have found that by adopting lithium hydroxide as a pH adjuster to adjust the pH, the lithium ions thereby introduced can improve the electrical conductivity and the glass transition temperature (Tg) of the obtained separator, thereby further improving the cycle performance and safety performance of the separator.

[0101] In some embodiments, in the separator of the present application, calculated based on the total weight of all the monomers contained in the linear copolymer, the first monomer accounts for 60% to 85% by weight, optionally 70% to 80% by weight, and / or the second monomer accounts for 1% to 10% by weight, optionally 5% to 10% by weight, and / or the third monomer accounts for 1% to 10% by weight, optionally 1% to 5% by weight, and / or the fourth monomer accounts for 1% to 20% by weight, optionally 10% to 15% by weight.

[0102] In some embodiments, the occupancy of the first type of monomer may be within a range formed by combining any two values from the following: 60 wt%, 62 wt%, 64 wt%, 66 wt%, 68 wt%, 70 wt%, 72 wt%, 74 wt%, 76 wt%, 78 wt%, 80 wt%, 82 wt%, or 85 wt%.

[0103] In some embodiments, the occupancy of the second type of monomer may be within a range formed by combining any two values from the following: 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%.

[0104] In some embodiments, the occupancy of the third type of monomer may be within a range formed by combining any two values from the following: 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%.

[0105] In some embodiments, the occupancy of the fourth type of monomer may be within a range formed by combining any two values from the following: 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, or 20 wt%.

[0106] By controlling the content of various monomers within the above ranges, the separator having the composite particles and the first inorganic particles of the present application can be obtained. In some embodiments, in the separator of the present application, the linear copolymer is A. 30% styrene - 15% methacrylic acid - 10% acrylamide - 15% acrylic acid - 5% acrylonitrile - 10% n - butyl acrylate - 2% methacrylic acid - 2 - hydroxyethyl - 1% E44 epoxy resin - 12% polyvinyl alcohol copolymer, and B. 35% Styrene - 15% Methacrylic Acid - 10% Acrylamide - 15% Acrylic Acid - 5% Acrylonitrile - 5% n - Butyl Acrylate - 2% 2 - Hydroxyethyl Methacrylate - 1% E44 Epoxy Resin - 12% Polyvinyl Alcohol Copolymer, and C. 30% Styrene - 15% Methacrylic Acid - 10% Acrylamide - 15% Acrylic Acid - 5% Acrylonitrile - 10% n - Butyl Acrylate - 3% 2 - Hydroxyethyl Methacrylate - 12% Polyvinyl Alcohol Copolymer, and D. 30% Styrene - 15% Methacrylic Acid - 15% Acrylamide - 15% Acrylic Acid - 5% Acrylonitrile - 5% n - Butyl Acrylate - 2% 2 - Hydroxyethyl Methacrylate - 1% E44 Epoxy Resin - 12% Polyvinyl Alcohol Copolymer, and E. 40% Styrene - 15% Acrylamide - 15% Acrylic Acid - 10% n - Butyl Acrylate - 5% n - Hexyl Methacrylate - 2% 2 - Hydroxyethyl Methacrylate - 1% E44 Epoxy Resin - 12% Polyvinyl Alcohol Copolymer, and F. May contain 35% Styrene - 15% Methacrylic Acid - 10% Acrylamide - 15% Acrylic Acid - 5% Acrylonitrile - 5% n - Butyl Acrylate - 2% Divinylbenzene - 1% E44 Epoxy Resin - 12% Polyvinyl Alcohol Copolymer, and wherein the average epoxy value of the E44 epoxy resin is 0.44, the degree of alcohol decomposition of the polyvinyl alcohol is 88% and the degree of polymerization is 1000, and the percentages are weight percentages calculated based on the total weight of all monomers of the monomers.

[0107] In some embodiments, in the separator of the present application, the weight - average molecular weight of the linear copolymer is 1×10 3 g / mol to 200×10 3 g / mol, and optionally 2×10 3 g / mol to 80×10 3 g / mol. In some embodiments, the weight - average molecular weight of the linear copolymer is the following 1×10 3 g / mol, 5×103 g / mol, 10×10 3 g / mol, 20×10 3 g / mol, 30×10 3 g / mol, 40×10 3 g / mol, 50×10 3 g / mol, 60×10 3 g / mol, 70×10 3 g / mol, 80×10 3 g / mol, 100×10 3 g / mol, 150×10 3 g / mol or 200×10 3 It may also be within a range formed by combining any two of these values of g / mol. Controlling the weight-average molecular weight of the linear copolymer within the above range can generate an appropriate chemical action between it and the particle material, and can also achieve an appropriate infiltration effect on the substrate.

[0108] In some examples, the weight-average molecular weight (Mw) of the linear copolymer is measured using Tosoh Corporation's HLC-8320GPC gel permeation chromatography (SuperMultipore HZ series semi-micro SEC column, and the standard sample is polystyrene).

[0109] In some embodiments, in the separator of the present application, the mass ratio of the composite particles to the adhesive is (80 - 90):(5 - 20), for example (80 - 90):(6 - 20), (80 - 90):(7 - 18), (80 - 90):(8 - 15), (80 - 90):(9 - 11), (80 - 90):10, (81 - 89):(5 - 20), (82 - 88):(5 - 20), (83 - 87):(5 - 20), (84 - 86):(5 - 20), 85:(5 - 20). The inventor has discovered that by mixing the composite particles and the adhesive in the coating according to this ratio, on the one hand, the safety performance and energy density of the battery can be improved simultaneously, and on the other hand, the adhesiveness between the separator and the electrode plate can be made appropriate, thereby improving the kinetic performance of the battery. In some other embodiments, in the separator of the present application, the mass ratio of the composite particles to the adhesive is (85 - 90):(8 - 15).

[0110] In some embodiments, the separator coating of the present application may further contain organic particles, and the organic particles include polytetrafluoroethylene particles, polychlorotrifluoroethylene particles, polyvinyl fluoride particles, polyvinylidene fluoride particles, polyethylene particles, polypropylene particles, polyacrylonitrile particles, polyethylene oxide particles, copolymer particles of fluorine-containing alkenyl monomer units and vinyl monomer units, copolymer particles of fluorine-containing alkenyl monomer units and acrylic acid-based monomer units, copolymer particles of fluorine-containing alkenyl monomer units and acrylate-based monomer units, and at least one of modified compound particles of each of the above homopolymers or copolymers. Referring to FIG. 4, the organic particles and the composite particles form the protrusions on the coating surface. Thereby, the cycle performance and safety performance of the battery can be improved.

[0111] In some embodiments, the organic particles of the separator coating of the present application form a third aggregate. Here, the Dv50 of the third aggregate is 5 μm - 30 μm, for example, 5 μm - 28 μm, 5 μm - 25 μm, 5 μm - 22 μm, 5 μm - 20 μm, 5 μm - 20 μm, 5 μm - 18 μm, 5 μm - 15 μm, 5 μm - 12 μm, 5 μm - 10 μm, 5 μm - 8 μm, 5 μm - 6 μm, etc.

[0112] In some embodiments, the third aggregate includes organic particles in the form of primary particles, and there is a gap between two adjacent organic particles. This gap may also serve as an ion transport channel, thereby improving the ionic conductivity of the separator. In some embodiments, the Dv50 of the organic particles in the form of primary particles is 50 nm - 400 nm, for example 50 nm - 375 nm, 75 nm - 375 nm, 100 nm - 350 nm, 125 nm - 325 nm, 150 nm - 300 nm, 175 nm - 275 nm, 200 nm - 250 nm, 200 nm - 225 nm, etc. In some other embodiments, the Dv50 of the organic particles in the form of primary particles is 100 nm - 200 nm.

[0113] In this application, Dv50 refers to the particle size corresponding to when the cumulative volume distribution rate reaches 50%, and Dv10 refers to the particle size corresponding to when the cumulative volume distribution rate reaches 10%. In this application, both the Dv10 and Dv50 of the composite particles may be measured by adopting the laser diffraction particle size analysis method. For example, referring to the standard GB / T 19077 - 2016, a laser particle size analyzer (such as Malvern Master Size 3000) is used for measurement. The Dv50 of the ion-conductive particles in the form of primary particles, the Dv50 of the polyacrylate particles in the form of primary particles, and the Dv50 of the polyacrylate particles in the form of secondary particles can be obtained by statistics from the separator SEM image. For example, a separator SEM image with a magnification of 10Kx is taken, each sample uses 5 replicates, each replicate uses 10 positions, 20 points are selected at each position for statistics, and finally the average value is taken as the corresponding particle size. The Dv50 of the first aggregate, the Dv50 of the second aggregate, and the Dv50 of the third aggregate can be obtained by using the statistics of the CP image of the separator. For example, a separator CP image with a magnification of 5Kx is taken, each sample uses 5 replicates, each replicate uses 10 positions, 20 points are selected at each position for statistics, and finally the average value is taken as the corresponding particle size.

[0114] In some embodiments, the mass ratio of the composite particles to the organic particles is (20 - 90):(0 - 70). For example, the mass ratio of the composite particles to the polyvinylidene fluoride particles is (20 - 90):(5 - 65), (20 - 90):(10 - 60), (20 - 90):(20 - 50), (20 - 90):(30 - 40), (30 - 80):(0 - 70), (40 - 70):(0 - 70), (50 - 60):(0 - 70), (30 - 80):(5 - 65), (40 - 65):(10 - 55), (45 - 60):(20 - 45), (55 - 60):(30 - 45). Thereby, the wettability and distribution uniformity of the electrolyte can be improved, the high-temperature storage performance of the battery can be improved, and the safety performance and cycle performance of the battery can be enhanced. In some other embodiments, the mass ratio of the composite particles to the organic particles is (45 - 90):(0 - 45). Thereby, the safety performance and cycle performance of the battery can be enhanced.

[0115] In some embodiments, the coating weight per side on the separator per unit area ≤ 1 g / m 2 For example, 0.2 g / m 2 - 1 g / m 2 0.3 g / m 2 - 0.9 g / m 2 0.4 g / m 2 - 0.8 g / m 2 0.5 g / m 2 - 0.7 g / m 2 0.5 g / m 2 - 0.6 g / m 2 When the coating weight per side on the separator per unit area is within a given range, on the premise of ensuring the cycle performance and safety performance of the battery, the energy density of the battery can be further improved.

[0116] In some embodiments, the coating may further contain other organic compounds, for example, polymers for improving heat resistance, dispersants, wetting agents, and other types of adhesives, etc. The above-mentioned other organic compounds are all non-particulate substances in the coating. This application does not particularly limit the types of the above-mentioned other organic compounds, and any known materials with good improvement performance may be selected.

[0117] In this application, the substrate is a porous membrane material having good chemical stability and mechanical stability. In some embodiments, the substrate may be a single-layer membrane material or a multilayer composite membrane material. When the substrate is a multilayer composite membrane material, the materials of each layer may be the same or different.

[0118] In some embodiments, in the separator of this application, the substrate may be a porous membrane or a porous non-woven web containing one or more of polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyaryl ether ketone, polyether imide, polyamide imide, polybenzimidazole, polyether sulfone, polyphenylene ether, cycloolefin copolymer, polyphenylene sulfide and polyethylene wax. In some other embodiments, the substrate is a porous membrane or a porous non-woven web containing polyethylene and / or polypropylene. By selecting the above substrate to manufacture the separator, it is advantageous for the substrate to be combined with the coating through an adhesive, and to form a separator that is moderately dense, porous and capable of lithium ion conduction.

[0119] In some embodiments, for the separator of the present application, the substrate has a porosity of 10%-95%, for example, 15%-90%, 20%-85%, 25%-80%, 30%-75%, 35%-70%, 40%-65%, 45%-60%, 50%-55%. In some other embodiments, the substrate of the separator of the present application has a porosity of 35%-45%. Thereby, while improving the ion conduction performance of the separator, the probability of the positive and negative electrode plates contacting each other can be reduced. In some embodiments, for the separator of the present application, the substrate has a pore diameter of 0.1μm-50μm, for example, 0.5μm-50μm, 1μm-45μm, 5μm-40μm, 10μm-35μm, 15μm-30μm, 20μm-25μm. In some other embodiments, for the separator of the present application, the substrate has a pore diameter of 0.1μm-5μm. Selecting the substrate having the above pore structure enables the separator to have good ion conduction performance, reduces the probability of the positive and negative electrode plates contacting directly, and further enhances the kinetic and safety performance of the battery core.

[0120] In some embodiments, the thickness of the substrate ≦ 10μm. For example, the thickness of the substrate may be 5μm-10μm, 5μm-9μm, 7μm-10μm. When the thickness of the substrate is controlled within a given range, the energy density of the battery can be further improved on the premise of ensuring the cycle performance and safety performance of the battery.

[0121] In some embodiments of the present application, the peeling force of the coating is 40N / m or more. After the separator is left in an environment of 150°C for 1 hour in an unclamped state, the thermal shrinkage rate in its longitudinal direction (MD) or transverse direction (TD) is both 5% or less, the destruction size by a heat gun at 200°C is 0, the adhesion force between the separator and the electrode is 1.0N / m or more, and the ionic conductivity at 25°C is 0.95ms / cm or more.

[0122] In some embodiments, for the material types of polyacrylate particles, organic particles, and adhesives, tests can be conducted by adopting devices and methods known in the art. For example, the material types can be determined by testing the infrared absorption spectrum of the material and determining the characteristic peaks contained therein. Specifically, infrared absorption spectrum analysis can be performed on the organic particles using instruments and methods known in the art. For example, for an infrared spectrometer, the IS10 type Fourier transform infrared spectrometer of Nicolet Company in the United States can be adopted and tested according to the general rules of the infrared absorption spectrum analysis method of GB / T6040-2002.

[0123] The second aspect of this application further provides a method for manufacturing a separator, and this method includes (1) providing a substrate, (2) forming a coating containing composite particles, first inorganic particles, and an adhesive on at least a part of the surface of the substrate, wherein the composite particles form protrusions on the coating surface, the composite particles include polyacrylate particles and ion-conductive particles, and there are ion-conductive particles between at least two of the polyacrylate particles, and here, the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06.

[0124] Specifically, the substrate, composite particles, first inorganic particles, and adhesive are the same as those described above, and will not be further described here.

[0125] In some embodiments, the separator includes a substrate and a coating, and the coating is installed on only one surface of the substrate.

[0126] In some embodiments, the separator includes a substrate and a coating, and the coating is installed on two surfaces of the substrate simultaneously.

[0127] In some embodiments, step (2) may be performed by adopting the following steps. (2-1) Provide a coating slurry, wherein the coating slurry contains composite particles, first inorganic particles, and an adhesive. (2-2) Apply the coating slurry onto at least one side of the substrate and dry it to obtain the separator.

[0128] In some embodiments, in step (2-1), the solvent in the coating slurry may be water, such as deionized water.

[0129] In some embodiments, in step (2-1), the coating slurry may further contain other organic compounds. For example, it may further contain a polymer for improving heat resistance, a dispersant, a wetting agent, and an emulsion adhesive. Here, all of the other organic compounds are non-particulate in the dried coating.

[0130] In some embodiments, in step (2-1), the coating slurry may further contain organic particles, and the organic particles include at least one of polytetrafluoroethylene particles, polychlorotrifluoroethylene particles, polyvinyl fluoride particles, polyvinylidene fluoride particles, polyethylene particles, polypropylene particles, polyacrylonitrile particles, polyethylene oxide particles, copolymer particles of fluorine-containing alkenyl monomer units and vinyl monomer units, copolymer particles of fluorine-containing alkenyl monomer units and acrylic acid monomer units, copolymer particles of fluorine-containing alkenyl monomer units and acrylate monomer units, and modified compound particles of each of the above homopolymers or copolymers.

[0131] In some embodiments, in step (2-1), the solid content of the coating slurry may be controlled to be 28%-45%, for example, it may be 30%-38%, and is calculated based on weight. When the solid content of the coating slurry is within the above range, the film surface problem of the coating can be effectively reduced, and the probability of coating unevenness can be reduced, thereby further improving the cycle performance and safety performance of the battery.

[0132] In some embodiments, in step (2-2), the coating is carried out by using a coater.

[0133] In the examples of this application, the model number of the coater is not particularly limited, and a commercially available coater may be used.

[0134] In some embodiments, in step (2-2), the coating may adopt processes such as transfer coating, rotary spray coating, dip coating, etc. For example, the coating may adopt transfer coating.

[0135] In some embodiments, the coater includes an intaglio roller, and the intaglio roller is used to transfer the coating slurry onto the substrate.

[0136] In some embodiments, the number of lines of the intaglio roller may be 100 LPI - 300 LPI, for example, 125 LPI - 190 LPI (LPI is lines / inch). When the number of lines of the intaglio roller is within the above range, it contributes to the control of the number of composite particles and polyvinylidene fluoride particles, thereby further improving the cycle performance and safety performance of the separator.

[0137] In some embodiments, in step (2-2), the coating speed may be controlled to be 30 m / min - 90 m / min, for example, 50 m / min - 70 m / min. When the coating speed is within the above range, the film surface problem of the coating can be effectively reduced, and the probability of coating unevenness can be reduced, thereby further improving the cycle performance and safety performance of the battery.

[0138] In some embodiments, in step (2-2), the linear velocity ratio of the coating may be controlled to be 0.8-2.5, for example, it may be 0.8-1.5 or 1.0-1.5.

[0139] In some embodiments, in step (2-2), the drying temperature may be 40°C-70°C, for example, it may be 50°C-60°C.

[0140] In some embodiments, in step (2-2), the drying time may be 10s-120s, for example, it may be 20s-80s or 20s-40s.

[0141] By controlling the above process parameters within a given range, the use performance of the separator of the present application can be further improved. Those skilled in the art may selectively adjust and control one or several of the above process parameters according to the actual production situation.

[0142] The above substrate, composite particles, first organic particles, adhesive and organic particles can all be commercially available.

[0143] The third aspect of the present application provides a battery, which includes the separator of the first aspect or the separator manufactured by adopting the second aspect.

[0144] The battery refers to a battery that can continue to be used by activating the active material by means of charging after discharging.

[0145] Generally, a battery includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. During the charge and discharge of the battery, active ions reciprocate between the positive electrode plate and the negative electrode plate for insertion and extraction. The separator is installed between the positive electrode plate and the negative electrode plate to play an isolation role. The electrolyte plays a role in conducting ions between the positive electrode plate and the negative electrode plate.

[0146] [Positive Electrode Plate] In a battery, the positive electrode plate generally includes a positive electrode current collector and a positive electrode film layer disposed on the positive electrode current collector, and the positive electrode film layer contains a positive electrode active material.

[0147] The positive electrode current collector may employ a conventional metal foil sheet or a composite current collector (a composite current collector may also be formed by disposing a metal material on a polymer base material). As an example, the positive electrode current collector may employ an aluminum foil.

[0148] The specific type of the positive electrode active material is not limited, and an active material known in the art and usable for a battery positive electrode may be employed, and those skilled in the art can select according to actual needs.

[0149] As an example, the positive electrode active material may include, but is not limited to, one or more of lithium transition metal oxides, lithium-containing phosphates having an olivine structure, and their modified compounds. Examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modified compounds. Examples of lithium-containing phosphates having an olivine structure may include, but are not limited to, one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite material of lithium manganese iron phosphate and carbon, and their modified compounds. These materials can all be obtained by commercial methods.

[0150] The modified compound of each of the above materials may be one that performs doping modification and / or surface coating modification on the material.

[0151] The positive electrode film layer generally further selectively includes an adhesive, a conductive agent, and other optional auxiliaries.

[0152] As an example, the conductive agent may be one or more of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, Super P (SP), graphene, and carbon nanofibers.

[0153] As an example, the adhesive may be one or more of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyacrylic acid (PAA), carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB).

[0154] [Negative electrode plate] In the battery, the negative electrode plate generally includes a negative electrode current collector and a negative electrode film layer disposed on the negative electrode current collector, and the negative electrode film layer contains a negative electrode active material.

[0155] The negative electrode current collector may employ a conventional metal foil sheet or a composite current collector (for example, a composite current collector may be formed by disposing a metal material on a polymer substrate). As an example, the negative electrode current collector may employ a copper foil.

[0156] The specific type of the negative electrode active material is not limited, and an active material known in the art and usable for a battery negative electrode may be employed, and those skilled in the art can select according to actual needs. As an example, the negative electrode active material may include, but is not limited to, one or more of artificial graphite, natural graphite, hard carbon, soft carbon, silicon-based materials, and tin-based materials. The silicon-based materials may include one or more of silicon alone, silicon oxides (such as silicon monoxide), silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based materials may include one or more of tin alone, tin acid compounds, and tin alloys. These materials can all be obtained by commercial methods.

[0157] In some embodiments, in order to further improve the energy density of the battery, the negative electrode active material may include a silicone-based material.

[0158] The negative electrode film layer generally further selectively includes an adhesive, a conductive agent, and other optional auxiliaries.

[0159] As an example, the conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0160] As an example, the adhesive may include one or more of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB).

[0161] As an example, the other optional auxiliaries may be a thickener and a dispersant (such as sodium carboxymethyl cellulose CMC-Na), or a PTC thermistor material.

[0162] [Electrolyte] The battery may include an electrolyte, and the electrolyte functions to conduct ions between the positive electrode and the negative electrode. The electrolyte may include an electrolyte salt and a solvent.

[0163] As an example, the electrolyte salt may include one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluoro(oxalato)borate (LiDFOB), lithium bis(oxalato)borate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorobis(oxalato)phosphate (LiDFOP), and lithium tetrafluoro(oxalato)phosphate (LiTFOP).

[0164] As an example, the solvent may include one or more of ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), ethyl methyl sulfone (EMS), and diethyl sulfone (ESE).

[0165] In some embodiments, the electrolyte further includes an additive. For example, the additive may include a negative electrode film-forming additive, may include a positive electrode film-forming additive, and further may include additives that can improve some performance of the battery, such as additives that improve the overcharge performance of the battery, additives that improve the high-temperature performance of the battery, and additives that improve the low-temperature performance of the battery.

[0166] In some embodiments, the battery may be a lithium-ion secondary battery.

[0167] The embodiments of the present application are not particularly limited to the shape of the battery, and it may be cylindrical, square, or any other arbitrary shape. FIG. 5 shows a battery 1 having a square structure as an example.

[0168] In some embodiments, the battery may include an exterior body. This exterior body is used to package the positive electrode plate, negative electrode plate, and electrolyte.

[0169] In some embodiments, the exterior body may include a case and a cover plate. Here, the case may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and side plates enclose to form a receiving cavity. The case has an opening communicating with the receiving cavity, and the cover plate can be covered on the opening so as to seal the receiving cavity.

[0170] The positive electrode plate, negative electrode plate, and separator can form an electrode assembly by a winding process or a lamination process. The electrode assembly is packaged in the receiving cavity. The electrolyte may employ an electrolytic solution, and the electrolytic solution is infiltrated into the electrode assembly. The number of electrode assemblies included in the battery may be one or more, and can be adjusted according to demand.

[0171] In some embodiments, the exterior body of the battery may be a hard case, such as a hard plastic case, an aluminum case, or a steel case.

[0172] The exterior body of the battery may be a pouch, such as a bag-shaped pouch. The material of the pouch may be plastic, and may include one or more of, for example, polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0173] In some embodiments, the battery can be assembled into a battery module, and the number of batteries included in the battery module may be plural, and the specific number can be adjusted according to the application and capacity of the battery module.

[0174] FIG. 6 shows a battery module 2 as an example. Referring to FIG. 6, in the battery module 2, a plurality of batteries 1 may be arranged in sequence along the longitudinal direction of the battery module 2. Of course, they may be arranged in any other way. Furthermore, these plurality of batteries 1 can be fixed by fasteners.

[0175] The battery module 2 may further include a housing having a receiving space, and the plurality of secondary batteries 1 are received in this receiving space. In some embodiments, the battery module may further be assembled into a battery pack, and the number of battery modules included in the battery pack can be adjusted according to the application and capacity of the battery pack.

[0176] FIGS. 7 and 8 show a battery pack 3 as an example. Referring to FIGS. 7 and 8, the battery pack 3 may include a battery box and a plurality of battery modules 2 installed in the battery box. The battery box includes an upper housing 4 and a lower housing 5, and the upper housing 4 is covered on the lower housing 5 to form a sealed space for accommodating the battery module 2. The plurality of battery modules 2 may be arranged in the battery box in any way.

[0177] [Power consumption device] This application further provides a power consumption device, which includes the battery for providing electrical energy. Specifically, the battery may be used as the power source of the power consumption device, or may be used as the energy storage unit of the power consumption device. The power consumption device may be a mobile device (such as a mobile phone, a notebook computer), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck), an electric train, a ship and a satellite, or an energy storage system, but is not limited thereto.

[0178] FIG. 9 shows a power consumption device as an example. This power consumption device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.

[0179] As another example of the power consumption device, it may be a mobile phone, a tablet computer, or a notebook computer. This power consumption device generally requires thinning, and a battery may be adopted as the power source.

[0180] In order to make the technical problems, technical solutions and beneficial effects solved by the embodiments of this application clearer, the following will be described in more detail with reference to the embodiments and the drawings. Obviously, the described embodiments are only some of the embodiments of this application, not all of them. The following description of at least one exemplary embodiment is actually only for the purpose of explanation and is by no means intended to limit this application and its application. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of this application.

[0181] I. Manufacture of the separator (1) Provide a PE substrate, the thickness of which is 9 μm, the pore diameter is 50 nm, and the porosity is 38%.

[0182] (2) Preparing a coating slurry by uniformly mixing composite particles, an adhesive, organic particles, and first inorganic particles in an appropriate amount of solvent deionized water to obtain a coating slurry with a solid content of 12% (calculated according to weight).

[0183] (3) After applying the coating slurry prepared in step (2) onto two surfaces of a PE substrate using a coater and then drying it, where the number of lines of the gravure roller of the coater is 125 LPI, the coating speed is 50 m / min, the linear speed ratio of coating is 1.15, the drying temperature is 50 °C, and the drying time is 25 s.

[0184] All materials used in the examples can be obtained commercially. For example, Here, the above composite particles are obtained by manufacturing using the following steps.

[0185] a. At room temperature, stir and uniformly mix the required monomers according to the ratio of 19 wt% of 2-hydroxyethyl acrylate, 27 wt% of n-butyl acrylate, 8 wt% of methyl methacrylate, 1 wt% of trimethylolpropane triacrylate, 20 wt% of acrylonitrile, and 25 wt% of acrylamide by weight percentage to obtain a mixed monomer. b. Add 2 kg of the mixed monomer, 60 g of sodium dodecyl sulfate emulsifier, 20 g of ammonium persulfate initiator, and 2.40 kg of deionized water to a 10 L four-necked flask equipped with a mechanical stirring device, a thermometer, and a condenser tube. Stir and emulsify at a rotation speed of 1600 rpm for 30 min, then heat up to 75 °C under the protection of nitrogen gas and react for 4 h. After that, adjust the pH to 6.5 using a 1 wt% NaOH aqueous solution and immediately cool to 40 °C or below to discharge the material to obtain an organic polymer in emulsion state, and its solid content is about 45 wt%. c. Add an appropriate amount of deionized water to the above organic polymer dry weight and silicon oxide according to a mass ratio of 9:1, stir for 1 h to mix well, then remove the solvent through spray drying to produce a powder. After crushing and grinding, composite particles with a Dv50 of 5 μm are obtained.

[0186] All the materials used in the examples can be obtained commercially. For example, The first inorganic particles may be purchased from Anhui Yishitong Technology Co., Ltd.

[0187] The organic particles may be purchased from Ruyuan Dongyangguang Fluororesin Co., Ltd.

[0188] The substrate may be purchased from Shanghai Enjie New Materials Co., Ltd.

[0189] The dispersant may be purchased from Changshu Weiyi Technology Co., Ltd.

[0190] The wetting agent may be purchased from Dow Chemical Company.

[0191] The corresponding parameters in the manufacturing process of separator 1-66 are shown in Table 1-7.

[0192]

Table 1

[0193]

Table 2

[0194]

Table 3

[0195]

Table 4

[0196]

Table 5

[0197]

Table 6

[0198]

Table 7

[0199] II. Battery Manufacturing Example 1 1. Manufacturing of the Positive Electrode Plate LiNi as the positive electrode active material 0.8 Co 0.1 Mn 0.1O2 (NCM811), carbon black (Super P) as the conductive agent, and polyvinylidene fluoride (PVDF) as the binder were uniformly mixed in an appropriate amount of N-methylpyrrolidone (NMP), which is a solvent, according to a mass ratio of 96.2:2.7:1.1 to obtain a positive electrode slurry. The positive electrode slurry was coated on a positive electrode current collector aluminum foil, and after drying, cold pressing, slitting, and cutting processes, a positive electrode plate was obtained. The positive electrode surface density is 0.207 mg / mm 2 and the tap density is 3.5 g / cm 3 .

[0200] 2. Manufacture of the negative electrode plate Artificial graphite as the negative electrode active material, carbon black (Super P) as the conductive agent, and styrene-butadiene rubber (SBR) and sodium carboxymethyl cellulose (CMC-Na) as the binder were uniformly mixed in an appropriate amount of deionized water, which is a solvent, according to a mass ratio of 96.4:0.7:1.8:1.1 to obtain a negative electrode slurry. The negative electrode slurry was coated on a negative electrode current collector copper foil, and after drying, cold pressing, slitting, and cutting processes, a negative electrode plate was obtained. The negative electrode surface density is 0.126 mg / mm 2 and the tap density is 1.7 g / cm 3 .

[0201] 3. Separator Separator 1 manufactured above was adopted as the separator.

[0202] 4. Manufacture of the electrolyte Ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed according to a mass ratio of 30:70 to obtain an organic solvent. A sufficiently dried electrolyte salt LiPF6 was dissolved in the above mixed solvent, and the concentration of the electrolyte salt was 1.0 mol / L. After uniform mixing, an electrolyte was obtained.

[0203] 5. Manufacture of the battery The positive electrode plate, separator, and negative electrode plate are stacked in order, with the separator positioned between the positive and negative electrode plates to perform an isolation function, and then wound to obtain an electrode assembly. The electrode assembly is placed in an outer package, and the manufactured electrolyte is injected into the dried secondary battery. After passing through the processes of vacuum packaging, standing, forming, and shaping, a secondary battery is obtained.

[0204] The secondary batteries of Example 2-65 and the comparative example are similar to the manufacturing method of the battery in Example 1. The difference is that different separators are used. The secondary batteries of Example 2-65 employ Separator 2-65, and the secondary batteries of the comparative example employ Separator 66.

[0205] III. Evaluation of the Adhesion Performance of the Separator The test process is as follows.

[0206] 1. The manufactured separator with a length of 300 mm and a width of 100 mm and the positive and negative electrode plates manufactured above were selected.

[0207] 2. The upper and lower surfaces of the separator were wrapped with paper and punched into samples with a size of 54.2 mm × 72.5 mm using a blade type and a punching machine.

[0208] 3. The punched separator samples and the positive electrode plate were aligned and stacked, and Teflon with a size of 130 mm × 130 mm was laid on the upper and lower surfaces respectively. The stacked samples were placed in the middle of a 200 mm × 200 mm cardboard and covered with another 150 mm × 160 mm cardboard.

[0209] 4. The stacked samples were placed in a flat press machine to adjust the pressure and air pressure. The flat press machine pressure = 2750 KG ± 10 KG (the contact area is approximately 54.2 mm × 72.5 mm, and the actual pressure after conversion is approximately 7 MPa), set at T = 25 °C, the time was set to 10 s, and pressurization was performed.

[0210] 5. The hot-pressed samples were punched into 72.5 mm × 15 mm strips using a blade type and a punching machine.

[0211] 6. One side of the positive electrode plate was fixed on the steel plate with double-sided tape, a separator was adhered to the other side, and an A4 paper strip with a width of 15 mm was integrally pasted to the separator using double-sided tape to complete the production of the test sample.

[0212] 7. The Gotech tensile machine was turned on, and the parameters were set in sequence as adhesion test, speed 50 mm / min, and starting jig pitch 40 mm.

[0213] 8. The test sample was placed between the jigs, the end of the steel plate was fixed to the lower chuck, and the A4 paper was fixed to the upper chuck. The upper and lower end chucks were tightened with jigs respectively.

[0214] 9. Click the tensile operation interface on the computer desktop, reset the force, displacement, etc., and then click "Start". After about 5 mm of preliminary tension, after the preliminary tension, reset the force, displacement, etc. again and start the test. During the test, fix the steel plate that fixes the electrode plate, and the tensile machine pulled the A4 paper strip upward to peel the separator from the positive electrode plate.

[0215] After the test was completed, the complete data was exported and saved.

[0216] 10. Measure at least 5 test samples for each group. If the reproducibility of the curves of the adhesion tests of the 5 test samples is relatively good, conduct the test for the next group. Otherwise, it is necessary to conduct further tests and continue until the reproducibility of the 5 test samples is relatively good.

[0217] 11. After the test was completed, an adhesion strength (N / m)-displacement curve was created, and the average value of the data points from the 100th to the 300th was taken as the adhesion force and recorded as F1.

[0218] 12. Repeat steps 1 to 11, where in the fourth step, change the pressure to 1178 KG ± 10 KG (the contact area is approximately 54.2 mm × 72.5 mm, and the actual pressure after conversion is equivalent to approximately 3 MPa), change the temperature T to 95 °C, and record the obtained adhesive force as F2.

[0219] IV. Evaluation of the ionic conductivity of the separator The test process is as follows.

[0220] 1. Sample punching: Lay a piece of white paper on a 45.3 mm * 33.7 mm blade die, spread the separator, lay another piece of white paper on the separator, cover it with a shim plate, put the separator and the shim plate into a cold flat press and press. 2. Symmetric battery assembly: (1) For the sample, (a) a separator, a 45.3 * 33.7 mm 2 square sheet, (b) a Pocket bag, (c) a cold-pressed electrode plate with FSNC (artificial graphite) coated on one side, 23 * 35 mm 2 and (d) an E-Black electrolyte are prepared. (2) For lamination, take a FSNC electrode plate, place it flat on the dust-free paper, absorb 300 μL of the electrolyte, drop 2 drops at the center of the electrode plate, spread the pressed separator layer obtained in step (1) flat on the electrode plate, gradually moisten it with the electrolyte, hold the Pocket bag with the left hand, use the tweezers with the right hand to lift a small corner from the lower left of the green tape, then roll up the green tape, hold the rolled-up green tape with the thumb of the left hand, keep the copper foil horizontal, insert the stacked electrode plate and separator between the green tape and the copper foil, quickly rub from the top sealing part outside the Pocket with the tweezers, check whether the green tape is flat, and continue rubbing until it is flat. Gradually inject the remaining electrolyte into the circular hole, insert another FSNC electrode plate between the upper part of the green tape and the current collector copper foil, align the positions with the lower electrode plate as much as possible, rub from the top sealing part with the tweezers to clamp the electrode plate position. All the above operations were completed in the glove box. Side packaging and bottom packaging were performed on the symmetric battery.

[0221] 3. Fixture Mounting for Symmetric Battery 4. Test: For the EC-Lab software, set the frequency range to 1 MHz to 1 kHz, the amplitude Va to 5 mV, the E range to -1 V to 1 V, Nd = 10, and Na = 3, 5. Data Processing: Calculate the separator electrical conductivity based on the formula σ = 1 / ρ = l / (k·S)*10, where σ is the separator electrical conductivity, mS / cm, l is the thickness of one layer of the separator, m, S is the effective area (Φ14 mm) of the separator in the symmetric battery, m 2 and k is the bulk resistance of the electrolyte transmission in one layer of the separator, Ohm.

[0222] V. Battery Performance Test (1) 25°C Cycle Performance At 25°C, the secondary batteries obtained by manufacturing in the examples and comparative examples were charged at a constant current of 1 C rate until the charge cut-off voltage reached 4.2 V, and then charged at a constant voltage until the current ≤ 0.05 C. After standing for 5 min, they were then discharged at a constant current of 0.33 C rate until the discharge cut-off voltage reached 2.8 V, and stood for 5 min. The battery capacity C0 at this time was recorded. The battery was subjected to 1500 cycles of charge and discharge according to this method, and the battery capacity after 1500 cycles was recorded as C1.

[0223] The cycle capacity retention rate of the battery at 25°C = C1 / C0 × 100%.

[0224] (2) 45°C Cycle Performance At 45°C, the secondary batteries obtained by manufacturing in the examples and comparative examples were charged at a constant current of 1 C rate until the charge cut-off voltage reached 4.2 V, and then charged at a constant voltage until the current ≤ 0.05 C. After standing for 5 min, they were then discharged at a constant current of 0.33 C rate until the discharge cut-off voltage reached 2.8 V, and stood for 5 min. The battery capacity at this time was recorded as C0. The battery was subjected to 1500 cycles of charge and discharge according to this method, and the battery capacity at this time was recorded as C1.

[0225] The cycle capacity retention rate of the battery at 45°C is C1 / C0×100%.

[0226] (3) Hot Box Test At 25°C, the secondary batteries manufactured in the examples and comparative examples were charged at a constant current of 1C rate until the charge cut-off voltage reached 4.2V, and then charged at a constant voltage until the current ≤ 0.05C. After standing for 5 minutes, each battery was tested with a jig in a DHG-9070A DHG series high-temperature oven. The temperature was raised from room temperature to 80°C ± 2°C at a rate of 5°C / min and maintained for 30 minutes. Subsequently, the temperature was raised at a heating rate of 5°C / min, and each time the temperature was raised by 5°C, it was kept warm for 30 minutes and continued until the battery core failed. The temperature at which the battery core began to fail was recorded.

[0227] (4) Thermal Propagation Performance Test At 25°C, the secondary batteries manufactured in the examples and comparative examples were charged at a constant current of 1C rate until the charge cut-off voltage reached 4.2V, and then charged at a constant voltage until the current ≤ 0.05C. After standing for 10 minutes, a metal heating plate was attached to the surface of the battery, and the battery was clamped using a jig at a position not in contact with the heating plate of the battery. Moreover, a 3-mm heat insulation pad was added between the jig and the battery, and the battery was heated at a constant temperature of 200°C until thermal runaway occurred in the battery. The time when thermal runaway occurred in the battery was recorded.

[0228] Table 8 shows the measured separator and battery performance data of Examples 1 - 65 and the comparative examples.

[0229]

Table 8

[0230] As can be seen from Table 8, in Examples 1-65, the ionic conductivity of the separator was 0.4-0.8 mS / cm, which was higher than 0.3173 mS / cm of the separator in all Comparative Examples. At 25 °C and 7 MPa, the adhesion of the separator to the positive electrode in Examples 1-65 was between 0.35 N / m and 2.05 N / m, which was lower than 2.50 N / m of the adhesion of the separator to the positive electrode in all Comparative Examples. At 95 °C and 3 MPa, the adhesion of the separator to the positive electrode in Examples 1-65 was between 1.45 N / m and 5.1 N / m, which was lower than 5.6 N / m of the adhesion of the separator to the positive electrode in all Comparative Examples. The capacity retention rate of the batteries of Examples 1-65 after 1500 cycles at 25 °C was 78% or more, and the capacity retention rate after 1500 cycles at 45 °C was 77% or more. The capacity retention rates after 1500 cycles at 25 °C and 45 °C were clearly higher than those of the batteries of Comparative Examples. The hot box failure temperature of Examples 1-65 was 130 °C or higher, and the heat propagation time was 570 s or more. This indicates that the separator adopted in this application has a relatively high ionic conductivity, the adhesion between the separator and the electrode plate is appropriate, and the kinetic performance and safety performance of the battery can be improved.

[0231] Finally, it should be noted that the above examples are only for explaining the technical solutions of this application and do not limit them. Although this application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or perform equivalent replacements for some or all of their technical features. These modifications or replacements do not depart from the essence of the corresponding technical solutions from the scope of the technical solutions of each example of this application, and they should all be included within the scope of the claims and the specification of this application. In particular, as long as there is no structural conflict, each technical feature mentioned in each example can be combined in any way. This application is not limited to the specific examples disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Description of Reference Signs

[0232] 1 Secondary battery 2 Battery module 3 Battery pack 4 Upper housing 5 Lower housing

Claims

1. A separator, comprising: a substrate; a coating formed on at least a part of the surface of the substrate, the coating including composite particles, first inorganic particles, and an adhesive, wherein the composite particles form protrusions on the coating surface, the composite particles include polyacrylate particles and ion-conductive particles, and the ion-conductive particles are present between at least two of the polyacrylate particles; wherein the mass ratio of the first inorganic particles to the ion-conductive particles is 1:0.007 - 0.06; the ion-conductive particles include at least one of second inorganic particles and organic-inorganic hybrid composite particles; the second inorganic particles include at least one of BaTiO₃, Pb(Zr,Ti)O₃ (PZT), Pb₁₋ₓLaₓZr₁₋ᵧTiᵧO₃ (PLZT), PB(Mg₃Nb₂ / ₃)O₃ - PbTiO₃ (PMN-PT), HfO₂, SrTiO₃, SnO₂, CeO₂, MgO, NiO, CaO, ZnO, ZrO₂, Y₂O₃, Al₂O₃, TiO₂, SiC, AlO(OH), Al₂O₃·H₂O, Li₃PO₄, LiₓTiᵧ(PO₄)₃, γ-AlOOH, BaSO₄, Mg(OH)₂, SiO₂, SrTiO₃, and at least one of BaTiO₃ and MgF₂; the organic-inorganic hybrid composite particles include metal atoms and / or their cations, and organic ligands, and the basic units constituting the organic-inorganic hybrid composite particles are periodically assembled along at least one spatial direction. The separator is as described above.

2. The separator according to claim 1, wherein, based on the mass of the coating, the content of the first inorganic particles is 50% - 70%.

3. The separator according to claim 1, wherein, based on the mass of the coating, the content of the ion-conductive particles is 0.5% - 3%.

4. The separator according to claim 1, wherein the dielectric constant of the ion-conductive particles is 5 or more.

5. The separator according to claim 1, wherein the composite particles include ion-conductive particles in the form of primary particles.

6. The ratio of Dv50 of the first inorganic particles to Dv50 of the ion-conductive particles in the primary particle form is 0.5 - 200:

1. The separator according to claim 5.

7. The Dv50 of the first inorganic particles is 0.5 μm - 2 μm. The separator according to claim 1.

8. The mass ratio of the composite particles to the first inorganic particles is (5 - 30):(50 - 70). The separator according to claim 1.

9. The Dv50 of the composite particles is larger than the Dv50 of the first inorganic particles. The separator according to claim 1.

10. The Dv50 of the composite particles ≧ 2.5 μm. The separator according to claim 1.

11. The composite particles include a first aggregate, and the first aggregate includes at least two ion-conductive particles. The separator according to claim 1.

12. 0.01 μm ≦ Dv50 of the first aggregate ≦ Dv10 of the composite particles. The separator according to claim 11.

13. The Dv50 of the ion-conductive particles in the primary particle form is 0.01 μm - 1 μm. The separator according to claim 6.

14. The composite particles include a second aggregate, and the second aggregate includes at least two of the polyacrylate particles. The separator according to claim 1.

15. The Dv50 of the second aggregate is 0.3 μm - 5 μm. The separator according to claim 14.

16. The polyacrylate particles include polyacrylate particles in the primary particle form and / or polyacrylate particles in the secondary particle form. The separator according to claim 1.

17. The Dv50 of the polyacrylate particles in the primary particle form is 50 nm - 400 nm. The separator according to claim 16.

18. The Dv50 of the polyacrylate particles in the secondary particle form is 2 μm - 15 μm. The separator according to claim 16.

19. The content of the ion-conductive particles in the composite particles is 1 wt% - 50 wt%. The separator according to claim 1.

20. The height of both sides of the protrusion is 15 μm - 60 μm. The separator according to claim 1.

21. The surface of the protrusion has the first aggregate. The separator according to claim 11.

22. The adhesive includes a linear copolymer having a hydroxyl group and a carboxylate. The separator according to claim 1.

23. The separator according to claim 1, wherein the adhesive contains a linear copolymer having a hydroxyl group, a carboxylate, an amide group, and an epoxy group.

24. The linear copolymer contains polymerization products of various monomers as follows, that is, (1) a first type of monomer containing at least one of acrylic acid, methacrylic acid, methyl methacrylate, tert-butyl methacrylate, isobornyl methacrylate, methylolacrylamide, acrylamide, styrene, and acrylonitrile; (2) a second type of monomer containing at least one of ethyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, decyl acrylate, cyclohexyl acrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-hexyl methacrylate, tridecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, ethylene urea ethyl methacrylate, dicyclopentenyl oxyethyl methacrylate, tetrahydrofuryl methacrylate, trifluoroethyl methacrylate, ethylene urea ethyl methacrylate, acrylic methacrylate, dicyclopentenyl oxyethyl methacrylate, and tetrahydrofuryl methacrylate; (3) a third type of monomer containing at least one of 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl acrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, γ-methacryloxypropyltrimethoxysilane, N-methylolacrylamide, N-butoxymethyl (meth)acrylamide, diacetoneacrylamide, ethyl acetoacetate methacrylate, divinylbenzene, and an epoxy resin having an epoxy value of 0.35 to 0.

50. The separator according to claim 22, which is a fourth monomer containing at least one of polyvinyl alcohol, polypropylene alcohol, polypropylene glycol, polyethylene glycol, and polyvinyl alcohol.

25. The separator according to claim 1, wherein the mass ratio of the composite particles to the adhesive is (80 - 90):(5 - 20).

26. The coating further includes organic particles, and the organic particles include polytetrafluoroethylene particles, polychlorotrifluoroethylene particles, polyvinyl fluoride particles, polyvinylidene fluoride particles, polyethylene particles, polypropylene particles, polyacrylonitrile particles, polyethylene oxide particles, copolymer particles of a fluorine-containing alkenyl monomer unit and a vinyl monomer unit, copolymer particles of a fluorine-containing alkenyl monomer unit and an acrylic acid-based monomer unit, copolymer particles of a fluorine-containing alkenyl monomer unit and an acrylate-based monomer unit, and at least one of modified compound particles of each of the above homopolymers or copolymers. The composite particles and the organic particles form the protrusions on the coating surface. The separator according to claim 1.

27. The separator according to claim 26, wherein the organic particles form a third aggregate.

28. The separator according to claim 27, wherein the Dv50 of the third aggregate is 5 μm - 30 μm.

29. The separator according to claim 27, wherein the third aggregate includes organic particles in the form of primary particles and there is a gap between two adjacent organic particles.

30. The separator according to claim 29, wherein the Dv50 of the organic particles in the form of primary particles is 50 nm - 400 nm.

31. The separator according to claim 26, wherein the mass ratio of the composite particles to the organic particles is (20 - 90):(0 - 70).

32. A method for manufacturing the separator according to any one of claims 1 to 31, comprising: (1) providing a substrate; (2) Forming a coating containing composite particles, first inorganic particles, and an adhesive on at least a part of the surface of the substrate, wherein the composite particles form protrusions on the coating surface, the composite particles include polyacrylate particles and ion conductive particles, and there are ion conductive particles between at least two of the polyacrylate particles, Here, a method for manufacturing a separator, wherein a mass ratio of the first inorganic particles to the ion conductive particles is 1:0.007 - 0.

06.

33. A battery comprising the separator according to any one of claims 1 to 31.

34. A power consumption device comprising the battery according to claim 33, wherein the battery is used to provide electrical energy.

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