Coating composition and preparation method thereof, isolating membrane, electrode plate, battery monomer and battery device

Abstract

The invention discloses a coating composition and a preparation method thereof, an isolating membrane, an electrode plate, a battery monomer and a battery device. The coating composition comprises inorganic particle powder, and the inorganic particle powder is in the form of spherical primary particles and is dispersed in the coating composition; the inorganic particle powder comprises one or more of bismuth oxide powder and lead oxide powder; the specific surface area of the inorganic particle powder is 8-10m < 2 > / g. According to the embodiment of the invention, when the coating composition is applied to the electrode assembly, the deterioration risk of rays to the electrode assembly and electrolyte can be reduced, so that the stability of the battery monomer is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to secondary batteries, and particularly relates to a coating composition and a preparation method thereof, a separator film, an electrode pole piece, a battery monomer and a battery device. BACKGROUND

[0002] Batteries have become one of the important energy sources in human production and life because they can convert chemical energy into electrical energy, and are widely used in many fields such as electric tools, electric vehicles, electronic devices and the like to provide electrical energy.

[0003] With the wide application of batteries in various fields, the requirements for their performance are also getting higher and higher, among which the stability of the battery has become one of the focuses. Therefore, how to improve the stability of the battery is one of the technical problems to be solved by the battery at present. SUMMARY

[0004] The embodiments of the present application provide a coating composition and a preparation method thereof, a separator film, an electrode pole piece, a battery monomer and a battery device, which can reduce the deterioration risk of the electrode assembly and the electrolyte caused by the rays, so as to improve the stability of the battery monomer.

[0005] In a first aspect, the embodiments of the present application provide a coating composition, which comprises inorganic particle powder, the inorganic particle powder is spherical primary particle dispersed in the coating composition; the inorganic particle powder comprises one or more of bismuth oxide powder and lead oxide powder; the specific surface area of the inorganic particle powder is 8-10 m 2 / g.

[0006] The coating composition in the embodiments of the present application, when used in the electrode assembly, has the inorganic particle powder with the specific morphology structure and the specific surface area. The inorganic particle powder with the specific morphology structure can provide more ray absorption directions, and the specific surface area in this range can provide more area regions for absorbing rays, thereby improving the absorption rate of rays, reducing the deterioration risk of the positive active material, the electrolyte, the binder and the electrode interface caused by the rays, and improving the stability of the battery monomer. Meanwhile, under the specific morphology structure and the specific surface area, the inorganic particle powder with the appropriate content can improve the total effective area for absorbing rays, so as to reduce the deterioration risk of the electrode assembly and the electrolyte caused by the rays, and improve the stability of the battery monomer.

[0007] In any embodiment of the present application, based on the coating composition, the mass percentage content of the inorganic particle powder is 1%-5%.

[0008] In any embodiment of this application, the volume distribution particle size Dv10 of the inorganic particulate powder is 5.00–6.50 μm; the volume distribution particle size Dv50 of the inorganic particulate powder is 12.00–14.00 μm; the volume distribution particle size Dv90 of the inorganic particulate powder is 24.00–27.00 μm; the volume distribution particle size Dv99 of the inorganic particulate powder is 39.00–42.00 μm; and the number distribution particle size Dn10 of the inorganic particulate powder is 0.90–1.40 μm.

[0009] In any embodiment of this application, the average particle size of the inorganic particulate powder is 19–22 μm.

[0010] In any embodiment of this application, the coating composition further includes a binder dispersed on the surface of the inorganic particulate powder, the binder including one or more of polyvinylidene fluoride, styrene-butadiene rubber and polymethyl methacrylate.

[0011] Secondly, embodiments of this application provide a method for preparing a coating composition, comprising: mixing materials containing soluble inorganic particulate salt and alkali, reacting to obtain an inorganic particulate sol; spray-drying the inorganic particulate sol under preset conditions to obtain a coating composition containing inorganic particulate powder; wherein the inorganic particulate powder is spherical and dispersed in the coating composition in a primary particle form; the specific surface area of ​​the inorganic particulate powder is 8-10 m² / g. 2 / g.

[0012] In any embodiment of this application, the soluble inorganic particulate salt includes one or more of soluble bismuth salt and soluble lead salt, wherein the bismuth salt includes one or more of bismuth nitrate, bismuth carbonate and bismuth chloride, and the lead salt includes one or more of lead nitrate, lead carbonate and lead chloride; the alkali includes one or more of ammonia, sodium hydroxide and sodium bicarbonate.

[0013] In any embodiment of this application, the molar ratio of soluble inorganic particulate salt to alkali is 1:3 to 1:10, based on the number of moles of inorganic particulate elements in the soluble inorganic particulate salt and the number of moles of hydroxide ions in the alkali.

[0014] In any embodiment of this application, the preset conditions include a spray drying temperature of 180–220°C.

[0015] In any embodiment of this application, the preset conditions include a spray drying airflow rate of 10–60 m³ / h. 3 / h.

[0016] In any embodiment of this application, the preset conditions include that the spray drying nozzle is a solid conical nozzle.

[0017] Thirdly, embodiments of this application provide a separating membrane, including a substrate and a coating disposed on at least one surface of the substrate; the coating includes the coating composition of the first aspect.

[0018] In any embodiment of this application, the substrate includes a porous base film with an average pore size of 30 to 200 nm.

[0019] In any embodiment of this application, the ratio of the average pore size of the porous base membrane to the average particle size of the inorganic particulate powder is 1.3*10. -3 ~10.5*10 -3 .

[0020] In any embodiment of this application, the thickness of the coating is 1 to 5 μm.

[0021] In any embodiment of this application, the areal density of the coating is 1–5 g / m³. 2 .

[0022] In any embodiment of this application, the absorption rate of the shielding membrane for radiation is 40% to 50%.

[0023] Fourthly, embodiments of this application provide an electrode sheet including a current collector and a material layer disposed on at least one surface of the current collector, the material layer including the coating composition of the first aspect.

[0024] Fifthly, embodiments of this application provide a battery cell including the coating composition of the first aspect.

[0025] In a sixth aspect, embodiments of this application provide a battery device including a battery cell as described in the fifth aspect. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 The diagram shows a schematic of a battery cell provided in some embodiments of this application.

[0028] Figure 2 An exploded view of a battery cell provided in some embodiments of this application is shown.

[0029] Figure 3 This document shows schematic diagrams of battery modules provided in some embodiments of this application.

[0030] Figure 4 This illustration shows a schematic diagram of a battery pack provided in some embodiments of this application.

[0031] Figure 5 yes Figure 4 The diagram shown is an exploded view of the battery pack.

[0032] Figure 6 A schematic diagram of an electrical device provided in some embodiments of this application is shown.

[0033] Figure 7 This shows a scanning electron microscope image of the bismuth oxide powder provided in Example 1 of this application.

[0034] Figure 8 This image shows a scanning electron microscope (SEM) image of the isolation film coating provided in Embodiment 1 of this application.

[0035] The accompanying drawings are not necessarily drawn to scale.

[0036] The reference numerals in the attached diagram are explained as follows: 1. Battery pack; 2. Upper casing; 3. Lower casing; 4. Battery module; 5. Battery cell; 51. Housing; 52. Electrode assembly; 53. Cover plate. Detailed Implementation

[0037] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0038] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments.

[0039] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the coating composition and its preparation method, separator, electrode sheet, battery cell, and battery device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0040] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0041] Unless otherwise specified, all embodiments and optional embodiments of this application may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of this application.

[0042] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions, and such technical solutions shall be deemed to be included in the disclosure of this application.

[0043] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0044] Rechargeable batteries, as a potential energy source for space equipment, are crucial for future space exploration. However, cosmic rays can induce the mixing of cations in the positive or negative electrode active materials, leading to polarization and capacity reduction. Furthermore, the degradation of the electrode interface accelerates the degradation of the positive or negative electrode, increasing battery polarization and further accelerating battery failure.

[0045] In view of this, embodiments of this application provide a coating composition and its preparation method, a separator, an electrode sheet, a battery cell, and a battery device, which can reduce the risk of radiation deterioration of electrode components and electrolyte, and improve the stability of battery cells.

[0046] In this application, cosmic rays refer to high-speed charged particles and photons from outer space. These rays have a very wide energy range, from low-energy electrons and protons to high-energy gamma rays. They mainly include the following types: high-energy cosmic rays (HECRs, such as X-rays and gamma rays), charged particles, neutral particles, photons, and heavy nuclei.

[0047] The battery cells disclosed in this application can be assembled into a power system for a battery device, which can help improve the safety performance and service life of the battery device.

[0048] Coating composition

[0049] This application provides a coating composition comprising inorganic particulate powder, wherein the inorganic particulate powder is spherically dispersed in the coating composition; the inorganic particulate powder includes one or more of bismuth oxide powder and lead oxide powder; the specific surface area of ​​the inorganic particulate powder is 8-10 m². 2 / g.

[0050] Primary particles refer to individual particles that have not been further aggregated or combined, and are the smallest structural units that constitute inorganic particulate powders.

[0051] The inorganic particulate powder in this embodiment has a spherical structure and a specific surface area within a certain range. Compared to conventional flake or rod-shaped inorganic particulate powders, the spherical structure is three-dimensionally symmetrical, with its surface convex in any direction. This morphological characteristic allows the spherical inorganic particulate powder to receive radiation from more directions. Furthermore, the surface curvature of the spherical structure results in less self-shading or shadowing areas, thus enabling more effective radiation reception. The specific surface area within this range provides a larger area for absorbing radiation, thereby increasing the radiation absorption rate, reducing the risk of radiation degradation to the positive electrode active material, electrolyte, binder, and electrode interface, and improving the stability of the battery cell. Simultaneously, when used in separators, the spherical structure and specific surface area of ​​the inorganic particulate powder can also improve the separator's oxidation resistance, high-temperature resistance, and wetting properties.

[0052] In the embodiments of this application, the specific surface area of ​​the inorganic particulate powder can be determined using instruments and methods known in the art, such as nitrogen adsorption specific surface area analysis and calculated using the BET (Brunauer Emmett Teller) method. The nitrogen adsorption specific surface area analysis can be performed using a NOVA2000e specific surface area and pore size analyzer from CANTA Corporation. As a specific example, the test method is as follows: Take 8.000g to 15.000g of inorganic particulate powder using a weighed empty sample tube. Stir the inorganic particulate powder evenly and weigh it. Place the sample tube in the NOVA2000e degassing station for degassing. Weigh the total mass of the degassed inorganic particulate powder and the sample tube. Subtract the mass of the empty sample tube from the total mass to calculate the mass G of the degassed inorganic particulate powder. The sample tube was placed in NOVA 2000e to measure the amount of nitrogen adsorbed on the surface of inorganic particulate powder under different relative pressures. The amount of monolayer adsorption was obtained based on the Brownnor-Etter-Teller multilayer adsorption theory and its formula, and then the total surface area A of the inorganic particulate powder was calculated. The specific surface area of ​​the inorganic particulate powder was obtained by calculating A / G.

[0053] In the embodiments of this application, the morphology of the inorganic particulate powder can be determined using instruments and methods known in the art, such as scanning electron microscopy.

[0054] Optionally, the specific surface area of ​​the inorganic particulate powder is independently selected from 8.0 m². 2 / g、8.1m 2 / g、8.2m 2 / g, 8.3m 2 / g, 8.4m 2 / g, 8.5m 2 / g, 8.6m 2 / g, 8.7m 2 / g, 8.8m 2 / g, 8.9m 2 / g, 9.0m 2 / g, 9.1m 2 / g, 9.2m 2 / g, 9.3m 2 / g, 9.4m 2 / g, 9.5m 2 / g, 9.6m 2 / g, 9.7m 2 / g, 9.8m 2 / g, 9.9m 2 / g, 10.0m 2 Any value in / g or a range of values ​​between both.

[0055] In some embodiments, the inorganic particulate powder may be bismuth oxide powder alone, lead oxide powder alone, or a mixture of bismuth oxide powder and lead oxide powder.

[0056] In this embodiment, the inorganic particulate powder is a separate bismuth oxide powder. When used in electrode components, it can improve the stability of individual battery cells while reducing the toxicity of individual battery cells to the human body and the natural environment.

[0057] In this embodiment, the inorganic particulate powder is a separate lead oxide powder. When used in electrode components, it can improve the stability of the battery cell while reducing the cost of the battery cell.

[0058] In this embodiment, the inorganic particulate powder is a mixture of bismuth oxide powder and lead oxide powder. When used in electrode components, it can reduce the toxicity of battery cells to humans and the natural environment, while also reducing the cost of battery cells. Those skilled in the art can adjust the ratio of bismuth oxide powder to lead oxide powder as needed to obtain mixed inorganic particulate powder.

[0059] In some embodiments, the inorganic particulate powder has a mass percentage content of 1% to 5% based on the coating composition.

[0060] With specific morphology and specific surface area, an appropriate amount of inorganic particulate powder can increase the total effective absorption area of ​​radiation, thereby reducing the risk of radiation deterioration of the electrode assembly and electrolyte, and improving the stability of the battery cell.

[0061] Optionally, based on the coating composition, the mass percentage of the inorganic particulate powder is independently selected from any value of 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, or a range between any two.

[0062] In some embodiments, the volume distribution particle size Dv10 of the inorganic particulate powder is 5.00–6.50 μm; the volume distribution particle size Dv50 of the inorganic particulate powder is 12.00–14.00 μm; the volume distribution particle size Dv90 of the inorganic particulate powder is 24.00–27.00 μm; the volume distribution particle size Dv99 of the inorganic particulate powder is 39.00–42.00 μm; and the number distribution particle size Dn10 of the inorganic particulate powder is 0.90–1.40 μm.

[0063] Dv10 represents the particle size corresponding to a cumulative volumetric distribution percentage of 10% for the material.

[0064] Dv50 represents the particle size at which the cumulative volumetric distribution percentage of the material reaches 50%.

[0065] Dv90 represents the particle size at which the cumulative volumetric distribution percentage of the material reaches 90%.

[0066] Dv99 represents the particle size corresponding to a cumulative volumetric distribution percentage of 99% for the material.

[0067] Dn10 represents the particle size corresponding to a cumulative percentage distribution of 10% of the material.

[0068] In the embodiments of this application, the particle size distribution of the inorganic particulate powder can achieve a suitable size and number of voids. Voids of a suitable size can alter the direction of radiation, causing scattering. Scattering increases the path length of radiation within the inorganic particulate powder, thereby increasing the chance of absorption. This reduces the possibility of radiation passing directly through without absorption due to excessively large voids, and also reduces the possibility of short radiation transmission paths due to excessively small voids. A suitable number of voids can increase the effective absorption area of ​​radiation, reducing the possibility of reduced effective absorption area due to excessive voids. Simultaneously, voids of a suitable size and number can improve the permeability of the separator, better promoting ion transport in the electrolyte, thereby increasing the charging rate of the battery cell. Furthermore, it can slow down the decomposition rate of functional groups in the electrolyte, reducing the risk of excessive internal pressure in the battery cell caused by the gas generated from the decomposition of electrolyte functional groups, thus improving the stability of the battery cell.

[0069] In this embodiment, the particle size distribution of the inorganic particulate powder can be determined using instruments and methods known in the art. For example, it can be tested using a laser particle size analyzer, referring to GB / T 19077-2016. During testing, 1g of the sample to be tested is added to a clean small beaker, followed by 20ml of deionized water. The mixture is sonicated at 53kHz / 120W for 5 minutes to ensure complete dispersion. The laser particle size analyzer is then turned on, and after cleaning the optical path system, the background is automatically tested. The sonicated solution is stirred to ensure uniform dispersion, and then placed into the sample cell as required. The particle size distribution is then measured. The testing instrument can be a MasterSizer 3000 laser particle size analyzer.

[0070] Optionally, the volume distribution particle size Dv10 of the inorganic particulate powder is independently selected from any value or a range between 5.00 nm, 5.05 nm, 5.10 nm, 5.15 nm, 5.20 nm, 5.25 nm, 5.30 nm, 5.35 nm, 5.40 nm, 5.45 nm, 5.50 nm, 5.55 nm, 5.60 nm, 5.65 nm, 5.70 nm, 5.75 nm, 5.80 nm, 5.85 nm, 5.90 nm, 5.95 nm, 6.00 nm, 6.05 nm, 6.10 nm, 6.15 nm, 6.20 nm, 6.25 nm, 6.30 nm, 6.35 nm, 6.40 nm, 6.45 nm, and 6.50 nm.

[0071] Optionally, the volume distribution particle size Dv50 of the inorganic particulate powder is independently selected from 12.00 nm, 12.05 nm, 12.10 nm, 12.15 nm, 12.20 nm, 12.25 nm, 12.30 nm, 12.35 nm, 12.40 nm, 12.45 nm, 12.50 nm, 12.55 nm, 12.60 nm, 12.65 nm, 12.70 nm, 12.75 nm, 12.80 nm, 12.85 nm, 12.90 nm, and 12.95 nm. The range of 13.00nm, 13.05nm, 13.10nm, 13.15nm, 13.20nm, 13.25nm, 13.30nm, 13.35nm, 13.40nm, 13.45nm, 13.50nm, 13.55nm, 13.60nm, 13.65nm, 13.70nm, 13.75nm, 13.80nm, 13.85nm, 13.90nm, 13.95nm, and 14.00nm, or any value between any two.

[0072] Optionally, the volume distribution particle size Dv90 of the inorganic particulate powder is independently selected from any value or a range between 5.00 nm, 5.05 nm, 5.10 nm, 5.15 nm, 5.20 nm, 5.25 nm, 5.30 nm, 5.35 nm, 5.40 nm, 5.45 nm, 5.50 nm, 5.55 nm, 5.60 nm, 5.65 nm, 5.70 nm, 5.75 nm, 5.80 nm, 5.85 nm, 5.90 nm, 5.95 nm, 6.00 nm, 6.05 nm, 6.10 nm, 6.15 nm, 6.20 nm, 6.25 nm, 6.30 nm, 6.35 nm, 6.40 nm, 6.45 nm, and 6.50 nm.

[0073] Optionally, the volume distribution particle size Dv99 of the inorganic particulate powder is independently selected from 39.00 nm, 39.05 nm, 39.10 nm, 39.15 nm, 39.20 nm, 39.25 nm, 39.30 nm, 39.35 nm, 39.40 nm, 39.45 nm, 39.50 nm, 39.55 nm, 39.60 nm, 39.65 nm, 39.70 nm, 39.75 nm, 39.80 nm, 39.85 nm, 39.90 nm, 39.95 nm, 40.00 nm, 40.05 nm, 40.10 nm, 40.15 nm, 40.20 nm, 40.25 nm, 40.30 nm, 40.35 nm, 40.40 nm, and 40.45 nm. The range of 40.50nm, 40.55nm, 40.60nm, 40.65nm, 40.70nm, 40.75nm, 40.80nm, 40.85nm, 40.90nm, 40.95nm, 41.00nm, 41.05nm, 41.10nm, 41.15nm, 41.20nm, 41.25nm, 41.30nm, 41.35nm, 41.40nm, 41.45nm, 41.50nm, 41.55nm, 41.60nm, 41.65nm, 41.70nm, 41.75nm, 41.80nm, 41.85nm, 41.90nm, 41.95nm, and 42.00nm, or any value or a range between any two.

[0074] Optionally, the volume distribution particle size Dn10 of the inorganic particulate powder is independently selected from 0.90 nm, 0.96 nm, 1.00 nm, 1.01 nm, 1.02 nm, 1.03 nm, 1.04 nm, 1.05 nm, 1.06 nm, 1.07 nm, 1.08 nm, 1.09 nm, 1.10 nm, 1.11 nm, 1.12 nm, 1.13 nm, 1.14 nm, 1.15 nm, 1.16 nm, 1.17 nm, 1.18 nm, and 1.18 nm. The value can be any value from m, 1.19nm, 1.20nm, 1.21nm, 1.22nm, 1.23nm, 1.24nm, 1.25nm, 1.26nm, 1.27nm, 1.28nm, 1.29nm, 1.30nm, 1.31nm, 1.32nm, 1.33nm, 1.34nm, 1.35nm, 1.36nm, 1.37nm, 1.38nm, 1.39nm, 1.40nm, or a range between any two.

[0075] In some embodiments, the average particle size of the inorganic particulate powder is 19–22 μm.

[0076] In the embodiments of this application, the average particle size of the inorganic particulate powder can further increase the specific surface area, thereby increasing the actual effective absorption area for radiation, improving the radiation absorption rate, reducing the risk of radiation deterioration of the positive electrode active material, electrolyte, binder and electrode interface, and improving the stability of the battery cell.

[0077] In the embodiments of this application, the average particle size of the inorganic particulate powder can be determined using instruments and methods known in the art. For example, it can be tested using a laser particle size analyzer, referring to GB / T 19077-2016. During testing, 1g of the sample to be tested is added to a clean small beaker, followed by 20ml of deionized water. The mixture is sonicated at 53kHz / 120W for 5 minutes to ensure complete dispersion. The laser particle size analyzer is then turned on, and after cleaning the optical path system, the background is automatically tested. The sonicated solution is stirred to ensure uniform dispersion, and then placed into the sample cell as required. The average particle size is then measured. The testing instrument can be a MasterSizer 3000 laser particle size analyzer.

[0078] Optionally, the average particle size of the inorganic particulate powder is independently selected from any value of 19.0 μm, 19.5 μm, 20.5 μm, 21.0 μm, 21.5 μm, 22.0 μm or a range between any two.

[0079] In some embodiments, the coating composition further includes a binder dispersed on the surface of the inorganic particulate powder, the binder including one or more of polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), and polymethyl methacrylate (PMMA).

[0080] In the embodiments of this application, the binder can fix spherical primary particles onto the electrode assembly, reduce the shedding of inorganic particle powder, and improve the stability of the battery cell.

[0081] In some embodiments, the coating may also include a dispersant, such as, but not limited to, polyacrylic acid dispersants or carboxymethyl cellulose dispersants. As an example, the dispersant may include, but is not limited to, one or more of sodium carboxymethyl cellulose, sodium polyacrylate, and ammonium polyacrylate.

[0082] Method of making a coating composition

[0083] This application provides a method for preparing a coating composition, comprising: S1, mixing materials containing soluble inorganic particulate salt and alkali, and reacting to obtain an inorganic particulate sol; S2, spray drying the inorganic particulate sol under preset conditions to obtain a coating composition containing inorganic particulate powder; wherein the inorganic particulate powder is spherical and dispersed in the coating composition in a primary particle form; the specific surface area of ​​the inorganic particulate powder is 8-10 m² / g. 2 / g.

[0084] The preparation method of the coating composition in this application embodiment can obtain inorganic particulate powder with spherical shape and specific surface area by adjusting the process parameters of spray drying, thereby increasing the absorption area, reducing the risk of radiation deterioration of electrode components and electrolyte, and improving the stability of battery cells.

[0085] In some embodiments, the soluble inorganic particulate salt includes one or more of soluble bismuth salt and soluble lead salt, wherein the bismuth salt includes one or more of bismuth nitrate, bismuth carbonate and bismuth chloride, and the lead salt includes one or more of lead nitrate, lead carbonate and lead chloride; the alkali includes one or more of ammonia, sodium hydroxide and sodium bicarbonate.

[0086] In some embodiments, the molar ratio of soluble inorganic particulate salt to alkali is 1:3 to 1:10, based on the number of moles of inorganic particulate elements in the soluble inorganic particulate salt and the number of moles of hydroxide ions in the alkali.

[0087] In the embodiments of this application, when calculating the molar ratio of soluble inorganic particulate salt to alkali, the number of moles of soluble inorganic particulate salt is based on the number of moles of inorganic particulate elements in the soluble inorganic particulate salt, and the number of moles of alkali can be based on the number of moles of hydroxide ions in the alkali or the number of hydroxide ions ionized from it.

[0088] Optionally, the molar ratio of the soluble inorganic particulate salt to the base is independently selected from any value of 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10 or any range between the two.

[0089] In some embodiments, the preset conditions include a spray drying temperature of 180–220°C.

[0090] In some embodiments, the preset conditions include a spray drying airflow rate of 10–60 m³ / h. 3 / h.

[0091] In some embodiments, the preset conditions include that the spray drying nozzle is a solid conical nozzle.

[0092] In this embodiment, during spray drying, materials containing soluble inorganic particulate salts and alkalis are mixed to obtain an inorganic particulate sol. The inorganic particulate sol passes through a nozzle to form droplets, which are then dried to obtain a coating composition containing inorganic particulate powder. The inorganic particulate powder with a preset particle size distribution and morphology can be obtained by simultaneously controlling the spray drying temperature and the spray drying air flow rate.

[0093] Different nozzle shapes produce different atomization effects. These differences directly affect the size, shape, and distribution of the sprayed droplets, thus influencing the morphology of the dried particles. The nozzle shape also affects the dynamic characteristics of the airflow within the spray area. Different airflow patterns cause changes in the trajectory and velocity of droplets in the hot medium, thereby affecting the drying process and the final particle morphology.

[0094] Optionally, the spray drying temperature is independently selected from any value of 180°C, 190°C, 200°C, 210°C, 220°C, or a range between any two.

[0095] Optionally, the air flow rate for spray drying is independently selected from 10m. 3 / h, 15m 3 / h, 20m 3 / h, 25m 3 / h, 30m 3 / h, 35m 3 / h, 40m 3 / h, 45m 3 / h, 50m 3 / h、55m 3 / h、60m 3 Any value in / h or any range of values ​​between the two.

[0096] In some embodiments, after step S2, the method further includes: mixing and drying the binder and dispersant with the inorganic particulate powder to obtain a coating composition containing the binder and the inorganic particulate powder.

[0097] Optionally, the mass ratio of binder, inorganic particulate powder to binder is 100:(5-30).

[0098] Separator film

[0099] This application provides an isolation membrane, including a substrate and a coating disposed on at least one surface of the substrate; the coating includes a coating composition of the first aspect.

[0100] In some embodiments, the substrate includes a porous base film with an average pore size of 30–200 nm.

[0101] In this embodiment, the average pore size of the porous membrane can be tested using a capillary porosity analyzer (bubble point method). An exemplary testing method is as follows: Take a circular sample with a diameter of 25 mm, and drop 3-5 drops of wetting liquid onto it. After the sample is completely wetted, place it in a mold, and then use an inert gas (such as nitrogen) to expel the wetting liquid from the pores of the sample. The extrusion pressure and flow rate are inversely proportional to the pore size. The average pore size of the sample is obtained through software sampling and pressure-pore size conversion analysis. The testing instrument can be a PMI CFP 1500 pore size analyzer, with a testing pressure ranging from 100 psi to 350 psi.

[0102] Optionally, the average pore size of the porous base film is independently selected from any value or a range between 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, and 200nm.

[0103] In some embodiments, the porous base membrane can be a single-layer film or a multi-layer composite film. When the porous base membrane is a multi-layer composite film, the materials of each layer can be the same or different.

[0104] In some embodiments, the porous base membrane may comprise a membrane or nonwoven web selected from any one or at least two of the following: polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymer, polyphenylene sulfide, and polyvinylnaphthalene.

[0105] In some embodiments, the thickness of the porous base film can be 4–12 μm, and optionally 4–9 μm.

[0106] In some embodiments, the ratio of the average pore size of the porous base membrane to the average particle size of the inorganic particulate powder is 1.3*10. -3 ~10.5*10 -3 .

[0107] In the embodiments of this application, the ratio of the average pore size of the porous base membrane to the average particle size of the inorganic particulate powder can reduce the risk of pore blockage and improve the air permeability and ion conduction characteristics of the separator.

[0108] Optionally, the ratio of the average pore size of the porous membrane to the average particle size of the inorganic particulate powder is independently selected from 1.3*10. -3 1.4*10 -3 1.5*10 -3 1.6*10 -31.7*10 -3 1.8*10 -3 1.9*10 -3 2.0*10 -3 2.5*10 -3 3.0*10 -3 3.5*10 -3 4.0*10 -3 4.5*10 -3 5.0*10 -3 5.5*10 -3 6.0*10 -3 6.5*10 -3 7.0*10 -3 7.5*10 -3 8.0*10 -3 8.5*10 -3 9.0*10 -3 9.5*10 -3 10.0*10 -3 10.5*10 -3 Any value in the range or any value between the two.

[0109] In some embodiments, the coating thickness is 1–5 μm.

[0110] In the embodiments of this application, the thickness of the coating can improve the absorption rate of the separator against radiation, while reducing the risk of reduced energy efficiency of individual battery cells due to the thickness of the coating.

[0111] Optionally, the thickness of the coating is independently selected from any value or a range between 1.0 μm, 1.5 μm, 2.0 μm, 2.5 μm, 3.0 μm, 3.5 μm, 4.0 μm, 4.5 μm, and 5.0 μm.

[0112] In some embodiments, the areal density of the coating is 1–5 g / m³. 2 .

[0113] Optionally, the areal density of the coating is independently selected from 1.0 g / m². 2 1.5g / m 2 2.0g / m 2 2.5g / m 2 3.0g / m 2 3.5g / m 2 4.0g / m 2 4.5g / m 2 5.0g / m 2 Any value in the range or any value between the two.

[0114] Areal density refers to the mass of the coating per unit area and can be tested using methods known in the art. For example, take a release liner coated on one side and cold-pressed (if it is a double-sided coated release liner, the coating on one side can be wiped off first), cut it into small circular pieces with an area of ​​S1, weigh them, and record their weight as M1. Then wipe off the coating of the release liner after weighing it, weigh the base film, and record it as M0. The areal density of the coating = (weight of the release liner M1 - weight of the base film M0) / S1.

[0115] In some embodiments, the thickness of the separator can be 5–14 μm, optionally 5–12 μm or 6–12 μm. This is beneficial for improving the energy density of the battery cell.

[0116] It should be noted that the coating parameters of the above-mentioned separators are coating parameters for one side of the porous base membrane. When the coating is applied to both sides of the porous base membrane, if the coating parameters of either side meet the requirements of this disclosure, it is considered to fall within the protection scope of this disclosure.

[0117] In some embodiments, the shielding membrane has an absorption rate of 40% to 50% for radiation.

[0118] Optionally, the absorption rate of the shielding membrane to radiation is independently selected from any value of 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, or a range between any two.

[0119] The method for calculating the absorption rate of radiation in this embodiment is as follows:

[0120] Incident gamma intensity (I0), transmitted gamma intensity (I), and the thickness (d) and linear attenuation coefficient (μ) of the irradiated material.

[0121] The formula for calculating gamma-ray absorptivity (A) is:

[0122] A = 1 - I / I0

[0123] The intensity of transmitted gamma rays also follows a relationship similar to the Lambert-Beer law with respect to the intensity of incident gamma rays, the thickness of the material, and the linear attenuation coefficient.

[0124] I = I0e(-μd)

[0125] The linear decay coefficient is related to the properties of the material (such as atomic number, density, etc.) and the energy of the gamma rays.

[0126] Electrode sheet

[0127] This application provides an electrode sheet, including a current collector and a material layer disposed on at least one surface of the current collector, the material layer including a coating composition of the first aspect.

[0128] Battery cell

[0129] This application provides a battery cell including a coating composition of the first aspect.

[0130] A single battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, while the uncoated positive current collector protrudes beyond it, serving as the positive electrode tab.

[0131] In addition, the battery cell also includes a housing for housing the electrode assembly and electrolyte, wherein the electrolyte can play a role in transferring electrons between the positive and negative electrode plates.

[0132] [Positive electrode plate]

[0133] In some embodiments, the positive electrode includes a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector and comprising a positive electrode active material, the positive electrode film layer further comprising a coating composition comprising the first aspect. For example, the positive current collector has two surfaces opposite each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0134] In some embodiments, the positive electrode active material includes a material capable of extracting and inserting lithium.

[0135] As examples, positive electrode active materials may include, but are not limited to, one or more of lithium transition metal oxides, metal chalcogenides, lithium-containing phosphates, and their respective modified compounds. Examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxides, lithium nickel oxides, lithium manganese oxides, lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, lithium titanium oxides, and their respective modified compounds. Lithium transition metal oxides may include, but are not limited to, layered structures and spinel structures. Examples of lithium-containing phosphates may include, but are not limited to, lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, lithium iron manganese phosphate and carbon composites, and their respective modified compounds.

[0136] In some embodiments, to further improve the energy density of a single battery cell, the positive electrode active material may include materials of the general formula Li. a Ni bCo c M d O e D f One or more of lithium transition metal oxides and their modified compounds. 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M may include, but is not limited to, one or more of Ge, Mo, Sn, Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and D may include, but is not limited to, one or more of N, F, S and Cl.

[0137] In some embodiments, the positive electrode active material may simultaneously comprise lithium transition metal oxide and lithium phosphate. This is advantageous for obtaining battery cells that balance high capacity and high reliability.

[0138] As an example, the positive electrode active material may include, but is not limited to, LiCoO2, LiNiO2, LiMnO2, and LiNi 1 / 2 Mn 1 / 2O2, LiMn2O4, Li 4 / 3 Ti 5 / 3 O4, LiNi 1 / 2 Mn 1 / 2 O2, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2(NCM523), LiNi 0.6 Co 0.2 Mn 0.2 O2(NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2(NCM811), LiNi 0.80 Co 0.15 Al 0.05 O2, LiFePO4, LiMnPO4, Li 1.13 Ti 0.57 Fe 0.3 One or more of S2.

[0139] In some embodiments, the positive electrode active material includes a material capable of extracting and inserting sodium. For example, the positive electrode active material may include, but is not limited to, one or more of layered transition metal oxides (including but not limited to P2 type, O3 type, etc.), polyanionic materials (such as phosphates, fluorophosphates, pyrophosphates, sulfates, etc.), and Prussian materials.

[0140] In some embodiments, as an example, the positive electrode active material may include, but is not limited to, NaFeO2, NaCoO2, NaCrO2, NaMnO2, NaNiO2, Na 0.67 MO2 (M includes at least two of Fe, Co, Cr, Mn, Ni, V, Ti, and Mo), NaMO2 (M includes at least two of Fe, Co, Ni, V, Ti, and Mo), NaFePO4, NaMnPO4, NaCoPO4, Na4Fe3(PO4)2O7, Na3V2(PO4)2F3, Na3V2(PO4)3, Prussian blue, Prussian white, and one or more of their respective modified compounds.

[0141] The modified compounds for the above-mentioned positive electrode active materials can be obtained by doping and / or surface coating of the positive electrode active materials.

[0142] In some embodiments, the positive electrode film may optionally include a positive electrode conductive agent. As an example, the positive electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0143] In some embodiments, the positive electrode film layer may optionally include a positive electrode binder. As an example, the positive electrode binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene oxide, fluorinated acrylate resins, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0144] In some embodiments, the positive current collector may be a metal foil or a composite current collector. An example of a metal foil is aluminum foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. As an example, the metal material may include, but is not limited to, one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymer substrate may include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0145] The positive electrode film is typically formed by coating a positive electrode slurry onto a positive electrode current collector, followed by drying and cold pressing. The positive electrode slurry is usually formed by dispersing positive electrode active materials, positive electrode conductive agents, positive electrode binders, and any other components in a solvent and stirring until homogeneous. The solvent can be N-methylpyrrolidone (NMP), but is not limited to this.

[0146] The coating comprising the coating composition of the first aspect is typically formed by preparing the coating composition of the first aspect into a slurry, applying it to the positive electrode current collector, and then drying and cold pressing it. Alternatively, the coating composition of the first aspect and the positive electrode active material can be prepared together into a slurry, applied to the positive electrode current collector, and then dried and cold pressed.

[0147] [Negative electrode plate]

[0148] The structure and composition of the negative electrode can be adjusted according to the type of battery cell.

[0149] In some embodiments, the negative electrode sheet may include a negative current collector and a metal layer disposed on at least one surface of the negative current collector. The metal layer is further provided with a coating comprising the coating composition of the first aspect. The metal material in the metal layer may include, but is not limited to, one or more of elemental lithium, lithium alloy, sodium, and sodium alloy.

[0150] The negative electrode active material may be any material known in the art that can be used in battery cells. As an example, the negative electrode active material may include, but is not limited to, one or more of natural graphite, artificial graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. Silicon-based materials may include, but are not limited to, one or more of elemental silicon, silicon oxide, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may include, but are not limited to, one or more of elemental tin, tin oxide, and tin alloys.

[0151] In some embodiments, the negative electrode film layer may further include a negative electrode conductive agent. As an example, the negative electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0152] In some embodiments, the negative electrode film layer may further include a negative electrode binder. As an example, the negative electrode binder may include, but is not limited to, one or more of styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, waterborne acrylic resins (e.g., polyacrylic acid PAA, polymethacrylic acid PMAA, sodium polyacrylate PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0153] In some embodiments, the negative electrode film layer may also include other additives. As an example, other additives may include thickeners, such as sodium carboxymethyl cellulose (CMC), PTC thermistor materials, etc.

[0154] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. As an example of a metal foil, copper foil may be used. The composite current collector may include a polymeric material substrate and a metal material layer formed on at least one surface of the polymeric material substrate. As an example, the metal material may include, but is not limited to, one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymeric material substrate may include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene, and polyethylene.

[0155] The negative electrode film is typically formed by coating a negative electrode slurry onto a negative electrode current collector, followed by drying and cold pressing. The negative electrode slurry is usually formed by dispersing the negative electrode active material, negative electrode conductive agent, negative electrode binder, and other optional additives in a solvent and stirring until homogeneous. The solvent can be N-methylpyrrolidone (NMP) or deionized water, but is not limited to these.

[0156] The negative electrode sheet does not exclude other additional functional layers besides the negative electrode film layer. For example, in some embodiments, the negative electrode sheet also includes a conductive undercoat layer (e.g., composed of a conductive agent and a binder) sandwiched between the negative electrode current collector and the negative electrode film layer and disposed on the surface of the negative electrode current collector.

[0157] In some embodiments, the negative electrode sheet can be made of foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not contain a negative electrode active material.

[0158] [Electrolytes]

[0159] This application does not impose specific limitations on the type of electrolyte, which can be selected according to requirements. For example, the electrolyte can be selected from at least one of solid electrolytes and liquid electrolytes (i.e., electrolyte solutions).

[0160] In some embodiments, the electrolyte is an electrolyte solution comprising an electrolyte salt and a solvent.

[0161] Taking a lithium battery cell as an example, the electrolyte salt may include, but is not limited to, one or more of the following: 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 difluorooxalate borate (LiDFOB), lithium dioxalate borate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorodioxalate phosphate (LiDFOP), and lithium tetrafluorooxalate phosphate (LiTFOP).

[0162] Taking sodium battery cells as an example, the electrolyte salt may include, but is not limited to, one or more of the following: sodium hexafluorophosphate (NaPF6), sodium tetrafluoroborate (NaBF4), sodium perchlorate (NaClO4), sodium hexafluoroarsenate (NaAsF6), sodium difluorosulfonyl imide (NaFSI), sodium difluoromethanesulfonyl imide (NaTFSI), sodium trifluoromethanesulfonate (NaTFS), sodium difluorooxalate borate (NaDFOB), sodium dioxalate borate (NaBOB), sodium difluorophosphate (NaPO2F2), sodium difluorodioxalate phosphate (NaDFOP), and sodium tetrafluorooxalate phosphate (NaTFOP).

[0163] The type of solvent is not specifically limited and can be selected according to actual needs. In some embodiments, as an example, the solvent may include at least one 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), butyl 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), methyl ethyl sulfone (EMS), and diethyl sulfone (ESE).

[0164] In some embodiments, the electrolyte may optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature power performance of the battery cell.

[0165] In some embodiments, the positive electrode, the separator, and the negative electrode can be fabricated into an electrode assembly using a winding process or a stacking process.

[0166] In some embodiments, the battery cell may include an outer packaging, at least one side of which is further provided with a coating comprising the coating composition of the first aspect. This outer packaging may be used to encapsulate the aforementioned electrode assembly and electrolyte.

[0167] In some embodiments, the outer packaging of the battery cell can be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of the battery cell can also be a soft pack, such as a pouch. The material of the soft pack can be plastic, such as at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0168] This application does not impose any particular limitation on the shape of the battery cell; it can be cylindrical, square, or any other arbitrary shape. Figure 1 The example shown is a square-structured battery cell 5.

[0169] In some embodiments, such as Figure 2 As shown, the outer packaging may include a housing 51 and a cover plate 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover plate 53 is used to cover the opening to close the receiving cavity. Positive electrode sheets, negative electrode sheets, and a separator may be formed into an electrode assembly 52 through a winding process or a stacking process. The electrode assembly 52 is encapsulated in the receiving cavity. Electrolyte is immersed in the electrode assembly 52. ​​The number of electrode assemblies 52 contained in a single battery cell 5 may be one or more, and can be adjusted according to requirements.

[0170] The method for preparing the battery cell of this application is well known. In some embodiments, a positive electrode, a separator, a negative electrode, and an electrolyte can be assembled to form a battery cell. As an example, the positive electrode, separator, and negative electrode can be formed into an electrode assembly through a winding process or a stacking process. The electrode assembly is placed in an outer packaging, dried, and then injected with electrolyte. After vacuum sealing, settling, formation, and shaping processes, a battery cell is obtained.

[0171] In some embodiments, the battery cells according to this application can be assembled into a battery module, and the number of battery cells contained in the battery module can be multiple, the specific number of which can be adjusted according to the application and capacity of the battery module.

[0172] Figure 3 This is a schematic diagram of battery module 4 as an example. Figure 3 As shown, in battery module 4, multiple battery cells 5 can be arranged sequentially along the length of battery module 4. Of course, they can also be arranged in any other manner. Furthermore, these multiple battery cells 5 can be fixed in place using fasteners.

[0173] Optionally, the battery module 4 may also include a housing with a receiving space in which multiple battery cells 5 are received.

[0174] In some embodiments, the battery modules described above can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.

[0175] Figure 4 and Figure 5 This is a schematic diagram of battery pack 1 as an example. Figure 4 and Figure 5 As shown, the battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3. The upper body 2 covers the lower body 3, forming a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0176] Battery device

[0177] This application provides a battery device, including a battery cell according to a fifth aspect. The battery device mentioned in this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0178] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0179] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0180] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0181] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0182] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0183] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0184] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0185] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0186] The technical solutions described in this disclosure are applicable to various electrical devices that use battery cells or battery devices, such as, but not limited to, mobile devices (e.g., mobile phones, tablets, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc. Battery cells and battery devices are used to store or provide electrical energy.

[0187] Figure 6 This is a schematic diagram of an example electrical device. The device could be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0188] Example

[0189] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0190] Example 1

[0191] 1. Preparation of the diaphragm

[0192] 1.1. Soluble inorganic particulate salt and alkaline solution are mixed in deionized water at a molar ratio of 1:3 and stirred evenly to obtain inorganic oxide particulate sol.

[0193] 1.2. The inorganic oxide particle sol is spray-dried at a preset temperature and a preset air flow rate using an electro-injection nozzle of a preset shape to prepare inorganic oxide particle powder.

[0194] 1.3. The inorganic oxide granular powder and polyacrylic acid prepared above are mixed evenly in deionized water at a solid mass ratio of 100:20 to obtain a diaphragm slurry (solid content of 25%). The slurry is uniformly coated on one surface of a substrate, dried to remove the solvent, and a diaphragm is obtained. The coating density of the coating composition on the substrate is 2.0 g / m². 2 The substrate is a commercially available PE microporous film with a thickness of 7μm and an average pore size of 80nm (from Zhuogao Electronic Technology Co., Ltd.).

[0195] 2. Preparation of the positive electrode sheet

[0196] Polyvinylidene fluoride (PVDF), lithium iron phosphate (LFP), conductive agent carbon black, and N-methylpyrrolidone (NMP) were thoroughly mixed at a mass ratio of 1.2:58.35:0.45:40 to prepare a positive electrode slurry. This positive electrode slurry was then subjected to a concentration of 200 g / m³. 2 The loading is uniformly coated on the positive current collector aluminum foil, and then dried, cold-pressed and cut to obtain the positive electrode sheet.

[0197] 3. Preparation of negative electrode sheet

[0198] Artificial graphite, conductive agent acetylene black, binder styrene-butadiene rubber (SBR), and thickener sodium carboxymethyl cellulose (CMC-Na) were added to deionized water at a mass ratio of 96.2:1.0:1.6:1.2. After thorough mixing, a negative electrode slurry (solid content 63%) was prepared. This negative electrode slurry was then subjected to a concentration of 98 g / m³. 2 The loading amount is coated on the negative electrode current collector copper foil, and then dried, cold pressed and slit to obtain the negative electrode sheet.

[0199] 4. Preparation of electrolyte

[0200] At 25°C, ethylene carbonate (EC), methyl ethyl carbonate (EMC), and diethyl carbonate (DEC) are mixed in a volume ratio of 1:1:1 to obtain a mixed solvent. LiPF6 is then dissolved in the above mixed solvent to obtain an electrolyte, wherein the concentration of LiPF6 is 1 mol / L.

[0201] 5. Preparation of battery cells

[0202] The above-mentioned positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, wound, and hot-pressed to form a battery cell; the battery cell is placed in an outer packaging, the electrolyte prepared above is added, and after processes such as encapsulation, standing, formation, and aging, a single battery cell is obtained.

[0203] Examples 2 and 3

[0204] The experimental procedure is basically the same as in Example 1, except that the soluble inorganic granular salt in step 1.1 is changed. The specific parameters are shown in Table 1 and Table 2.

[0205] Comparative Examples 1 and 2

[0206] The experimental steps are basically the same as in Example 1, except that the nozzle shape in step 1.2 is changed. Specific parameters are shown in Tables 1 and 2.

[0207] Comparative Examples 3 and 4

[0208] The experimental steps are basically the same as in Example 1, except that the preset temperature in step 1.2 is changed. For specific parameters, please refer to Table 1 and Table 2.

[0209] Table 1 Preparation process of inorganic particulate powder

[0210]

[0211]

[0212] Table 2 Characterization of Inorganic Particle Powder Structure

[0213]

[0214] The inorganic particulate powder structure characterization methods in Table 2 are as follows:

[0215] Morphology: SEM uses an electron beam to scan the sample surface, generating various physical signals, such as secondary electrons and backscattered electrons. By detecting these signals, morphological information of the sample surface can be obtained.

[0216] Specific surface area: BET method: Based on BET theory, the specific surface area is calculated by measuring the amount of gas adsorbed on the solid surface under different relative pressures to obtain adsorption isotherms.

[0217] Particle size distribution:

[0218] Laser particle size analysis: This method uses laser light to irradiate particles and determines their particle size distribution by measuring the scattering angle and intensity of the laser light. The scattering of laser light by particles is related to factors such as particle size, shape, and refractive index. The particle size can be calculated based on Mie scattering theory.

[0219] Average particle size:

[0220] Arithmetic mean diameter: The average value obtained by adding up the diameters of all particles and then dividing by the total number of particles.

[0221] Data Analysis

[0222] The performance of the individual cells in Examples 1-3 and Comparative Examples 1-4 was tested using the following methods:

[0223] X-ray absorption rate: Tested according to GB / T 4835.1-2012 Radiation Protection Instruments - Ambient and / or Directional Dose Equivalent (Rate) Meters and / or Monitors for β, X and γ Radiation - Part 1: Portable Workplace and Environmental Measuring and Monitoring Instruments. The IMI Inspector Alert manufactured by TESTO GmbH, Germany was selected. TM A V2 radiation detector was used to measure radiation dose. According to GB18871-2002, the Co-type radiation source was selected for exemption from activity limits. 60 It is 1E+4Bq(<1E+5Bq)3.

[0224] Cycle stability: At 20 ± 5℃, the prepared battery cells were charged at a constant current of 0.1C to 3.7-4.2V, and then charged at a constant voltage until the current reached 0.01C. At this point, the battery cell was fully charged, and the charging capacity was recorded as the first charge capacity. After the battery cell was allowed to stand for 5 minutes, it was discharged at a constant current of 0.1C to 2.2-2.5V. This constituted one charge-discharge cycle, and the discharge capacity was recorded as the first discharge capacity. The battery cells were subjected to cycle charge-discharge tests using the above method, and the discharge capacity after each cycle was recorded until the discharge capacity of the battery cell decreased to 80% of the first discharge capacity. The number of cycles at this point was used to characterize the cycle performance of the battery cell. The higher the number of cycles, the better the cycle performance.

[0225] Table 3. Stability Test of Individual Cells

[0226] Serial number Absorption rate Cycle stability Example 1 40％ 95％ Example 3 50％ 93％ Example 4 46％ 92％ Comparative Example 1 30％ 87％ Comparative Example 2 35％ 90％ Comparative Example 3 33％ 92％ Comparative Example 4 35％ 90％

[0227] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A coating composition, characterized in that, The coating composition includes inorganic particulate powder, wherein the inorganic particulate powder is dispersed in the form of spherical primary particles; The inorganic particulate powder includes one or more of bismuth oxide powder and lead oxide powder; The inorganic particulate powder has a specific surface area of ​​8-10 m². 2 / g.

2. The coating composition according to claim 1, characterized in that, Based on the coating composition, the inorganic particulate powder has a mass percentage content of 1% to 5%.

3. The coating composition according to claim 1 or 2, characterized in that, The volume distribution particle size Dv10 of the inorganic particulate powder is 5.00–6.50 μm; The volume distribution particle size Dv50 of the inorganic particulate powder is 11.5.00~14.70μm; The volume distribution particle size Dv90 of the inorganic particulate powder is 23.00–27.00 μm; The volume distribution particle size Dv99 of the inorganic particulate powder is 35.00–42.00 μm; The inorganic particulate powder has a particle size Dn10 of 0.90–1.40 μm.

4. The coating composition according to any one of claims 1-3, characterized in that, The average particle size of the inorganic particulate powder is 19–22 μm.

5. The coating composition according to any one of claims 1-4, characterized in that, The coating composition further includes a binder dispersed on the surface of the inorganic particulate powder, the binder comprising one or more of polyvinylidene fluoride, styrene-butadiene rubber, and polymethyl methacrylate.

6. A method for preparing a coating composition, characterized in that, include: Materials containing soluble inorganic particulate salts and alkalis are mixed and reacted to obtain inorganic particulate sol. The inorganic particle sol is spray-dried under preset conditions to obtain a coating composition containing inorganic particle powder. The inorganic particulate powder is dispersed in the coating composition as spherical primary particles; The inorganic particulate powder has a specific surface area of ​​8-10 m². 2 / g.

7. The preparation method according to claim 6, characterized in that, The soluble inorganic particulate salt includes one or more of soluble bismuth salts and soluble lead salts, wherein the bismuth salt includes one or more of bismuth nitrate, bismuth carbonate, and bismuth chloride, and the lead salt includes one or more of lead nitrate, lead carbonate, and lead chloride. The alkali includes one or more of ammonia, sodium hydroxide, and sodium bicarbonate.

8. The preparation method according to claim 6 or 7, characterized in that, Based on the number of moles of inorganic particulate elements in the soluble inorganic particulate salt and the number of moles of hydroxide ions in the alkali, the molar ratio of the soluble inorganic particulate salt to the alkali is 1:3 to 1:

10.

9. The preparation method according to any one of claims 6-8, characterized in that, The preset conditions include at least one of the following: The spray drying temperature is 180–220℃; The air flow rate for spray drying is 10–60 m³ / h. 3 / h; The spray dryer uses a solid conical nozzle.

10. A separating membrane, characterized in that, It includes a substrate and a coating disposed on at least one surface of the substrate; the coating includes the coating composition of any one of claims 1-5.

11. The separator membrane according to claim 10, characterized in that, The substrate includes a porous base film, the average pore size of which is 30–200 nm; and / or, The ratio of the average pore size of the porous base membrane to the average particle size of the inorganic particulate powder is 1.3*10. -3 ~10.5*10 -3 .

12. The separator according to claim 10, characterized in that, The coating thickness is 1–5 μm; and / or, The areal density of the coating is 1-5 g / m³. 2 .

13. The separator membrane according to any one of claims 10-12, characterized in that, The shielding membrane has an absorption rate of 40% to 50% for radiation.

14. An electrode sheet, characterized in that, It includes a current collector and a material layer disposed on at least one surface of the current collector, the material layer comprising the coating composition of any one of claims 1-5.

15. A single battery cell, characterized in that, The coating composition comprising any one of claims 1-5.

16. A battery device, characterized in that, Includes the battery cell as described in claim 15.

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