Diaphragm and preparation method thereof, secondary battery, and electrical device

Abstract

The present application relates to the field of secondary battery technology, and specifically to a diaphragm and its preparation method, a secondary battery, and an electrical device. The diaphragm of the present application comprises carboxyl-modified diamond, an aluminate coupling agent, a carboxylate compound, and a binder in a mass ratio of (0.04-0.06): (0.8-1.2): (0.2-0.3): (0.4-0.6). The carboxylate compound comprises one or more compounds having the structure represented by formula (I): The diaphragm provided by the present application has good wettability and interfacial properties, thereby effectively improving the electrochemical properties of the secondary battery, such as capacity, coulombic efficiency, and cycle stability.

Description

Technical Field

[0001] The present application relates to the technical field of secondary batteries, and in particular to a diaphragm and a preparation method thereof, a secondary battery, and an electrical device. Background Art

[0002] With the rapid development of electrical devices such as new energy vehicles and portable electronic devices, secondary batteries, as key energy storage devices, have become a focus of scientific research and industry for improving their energy density, cycle performance, and safety. The diaphragm is a key component of secondary batteries. It is a thin film that separates the positive and negative electrodes during electrolysis and prevents energy loss from direct reactions. The performance of the diaphragm determines the battery's interface structure and internal resistance, which directly impacts the battery's capacity, cycle life, and safety.

[0003] Currently, polyolefin separators are widely used due to their lightweight, flexible, and easy processing. However, due to their inherent structural characteristics, surface hydrophobicity, and low softening temperature, polyolefin separators have the disadvantages of poor wettability and low interfacial properties, which in turn leads to reduced battery cycle performance. Summary of the Invention

[0004] Based on this, the present application provides a diaphragm and a preparation method thereof, a secondary battery, and an electrical device. The diaphragm provided in the present application has good wettability and interface properties, thereby effectively improving the cycle performance of the secondary battery.

[0005] In a first aspect of the present application, a diaphragm is provided, comprising carboxyl-modified diamond, an aluminate coupling agent, a carboxylate compound, and a binder in a mass ratio of (0.04-0.06):(0.8-1.2):(0.2-0.3):(0.4-0.6);

[0006] The carboxylic acid ester compound includes one or more compounds having the structure shown in formula (I):

[0007] ; R 11 and R 12 Each independently selected from C3~C 10 Alkyl or C3~C 10 Ar is selected from S1 substituted or unsubstituted C6~C 20 Arylene; S1 is selected from C1~C 10 Alkyl, C1~C 10 haloalkyl or ; R 13 Selected from C3~C 10 Alkyl or C3~C 10 Halogenated alkyl.

[0008] In one embodiment, R 11 and R 12 Each independently selected from C3~C8 alkyl; Ar is selected from C6~C 10 Aromatic group.

[0009] In one embodiment, the carboxylic acid ester compound includes one or more compounds having the structure shown in formula (II): ; m1 and m2 are each independently 1, 2, 3, 4 or 5.

[0010] In one embodiment, the aluminate coupling agent includes one or more of aluminate coupling agent LS60, aluminate coupling agent LS62, aluminate coupling agent LS821 and aluminate coupling agent NXH-821.

[0011] In one embodiment, the binder includes one or more of polyvinylidene fluoride, styrene-butadiene rubber and carboxymethyl cellulose.

[0012] In one embodiment, the steps of preparing the carboxyl-modified diamond include:

[0013] Heat-treating the nanodiamond in air or oxygen environment to prepare the carboxyl-modified diamond;

[0014] The surface of the nanodiamond has one or more of hydroxyl, carbonyl and carboxyl functional groups; the process parameters of the heat treatment include: heating to 400°C~450°C at a heating rate of 3°C / min~5°C / min, and keeping warm for 4h~10h.

[0015] A second aspect of the present application provides a method for preparing the diaphragm according to any one of the embodiments of the first aspect of the present application, comprising the following steps:

[0016] Mixing the carboxyl-modified diamond, the aluminate coupling agent, the carboxylate compound, and the binder in a solvent to prepare a mixed slurry;

[0017] The mixed slurry is formed into a film and dried to prepare the separator.

[0018] In one embodiment, in the mixed slurry, the mass volume ratio of the aluminate coupling agent to the solvent is (0.005~0.1) g:1 mL.

[0019] In a third aspect of the present application, a secondary battery is provided, comprising a positive electrode sheet, a negative electrode sheet, a separator separated between the positive electrode sheet and the negative electrode sheet, and an electrolyte; the separator is the separator described in any embodiment of the first aspect of the present application.

[0020] In a fourth aspect of the present application, an electrical device is provided, comprising the secondary battery described in the third aspect of the present application.

[0021] The diaphragm provided in this application has at least the following beneficial effects:

[0022] The diaphragm provided in the present application includes carboxyl-modified diamond, aluminate coupling agent, carboxylate compound and binder in a specific mass ratio. Among them, the aluminate coupling agent can form a chemical bond between the carboxyl-modified diamond and the binder, thereby enhancing the bonding force and bonding strength between the components. The carboxylate compound of a specific structure and the carboxyl-modified diamond cooperate with each other to adjust the mechanical properties of the diaphragm. Further supplemented with a binder, the internal bonding force of the diaphragm is increased and the diaphragm structure is more stable, which helps to prevent the diaphragm from rupturing and being damaged during the charge and discharge process of the battery, thereby ensuring the stability of the battery. In addition, the polar groups of the carboxylate compound and the organic groups in the aluminate coupling agent can interact with the polarity analysis in the electrolyte or the organic solvent in the electrolyte to enhance the affinity of the diaphragm to the electrolyte, thereby improving the wetting properties of the diaphragm.

[0023] In summary, the diaphragm provided in this application can effectively improve the wettability and interfacial properties of the diaphragm by selecting a specific mass ratio of carboxyl-modified diamond, aluminate coupling agent, carboxylate compound and binder, so as to improve the electrochemical properties of the secondary battery such as capacity, coulombic efficiency, and cycle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a scanning electron microscope image of the diaphragm prepared in Example 1 of the present application;

[0025] Figure 2 This is a real picture of the diaphragm prepared in Example 2 of the present application;

[0026] Figure 3 This is a performance diagram of the contact angle between the diaphragm prepared in Example 3 of the present application and the electrolyte;

[0027] Figure 4 The diaphragms prepared in Example 1 and Comparative Example 1 are assembled into silicon negative electrode half-cells. The cycle performance of the silicon negative electrode half-cells at a charge and discharge rate of 0.5C is shown.

[0028] Figure 5 This is a real shot of the diaphragm prepared in Comparative Example 2 of this application;

[0029] Figure 6 This is a real shot of the diaphragm prepared in comparative example 3 of this application. DETAILED DESCRIPTION

[0030] The following, in conjunction with specific examples, provides a further complete and clear description of the separator and its preparation method, secondary battery, and electrical device of the present application. The present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0031] In this application, the terms “further”, “further”, “particularly”, etc. are used for descriptive purposes to indicate differences in content, but should not be understood as limiting the scope of protection of this application.

[0032] In this application, the terms "optionally," "optional," and "optional" refer to options that are optional and may or may not be present, i.e., to the selection of either option from the two parallel options of "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or constraints, each "option" is independent.

[0033] In this application, when referring to a numerical interval (i.e., a numerical range), unless otherwise specified, the optional numerical distribution is considered continuous within the above numerical interval and includes the two numerical endpoints of the numerical range (i.e., the minimum and maximum values), as well as each numerical value between the two numerical endpoints. Unless otherwise specified, when a numerical interval refers only to integers within the numerical interval, it includes the two endpoint integers of the numerical range, as well as each integer between the two endpoints. In this article, it is equivalent to directly listing each integer, such as t is an integer selected from 1 to 10, indicating that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges included therein.

[0034] Unless otherwise specified, the temperature parameters in this application allow for both constant temperature treatment and temperature fluctuations within a certain temperature range. It should be understood that the constant temperature treatment allows for temperature fluctuations within the accuracy range of instrument control. Fluctuations within ranges such as ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are permitted.

[0035] In this application, "alkyl" refers to a saturated hydrocarbon group containing primary (normal) carbon atoms, secondary carbon atoms, tertiary carbon atoms, quaternary carbon atoms, or a combination thereof. Phrases containing this term, for example, "C3~C 10 "Alkyl" refers to an alkyl group containing 3 to 10 carbon atoms, each occurrence of which can be independently C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C8 alkyl or C 10Suitable examples include, but are not limited to, 1-propyl (n-propyl, n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-butyl, n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)2), 1-butyl (n-butyl, n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH 3)CH2CH3), tert-butyl (1,1-dimethylethyl, 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl -2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (n-hexyl, -CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl (-CH(CH3)CH(CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2) and 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2).

[0036] As used herein, "haloalkyl" refers to an "alkyl" group in which a halogen atom replaces a hydrogen atom in the alkyl group. It is understood that the number of halogen atoms substituted is ≤ the number of hydrogen atoms in the alkylene group. As used herein, "halogen atom" refers to F, Cl, Br, or I.

[0037] In this application, "aromatic group" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing a hydrogen atom. It can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic rings, at least one is an aromatic ring system. Phrases containing this term, for example, "C6~C 20 "Aryl" refers to an aromatic group containing 6 to 20 atoms, each occurrence of which can be independently C6 aromatic, C 10 Suitable examples include, but are not limited to, benzene and naphthalene. "Arylene" refers to an aromatic hydrocarbon group derived from an "aryl" group by removing a hydrogen atom.

[0038] Among the methods for modifying polyolefin separators, some researchers have combined inorganic materials with polyolefin separators to create separator materials. However, the chemical properties of inorganic materials and polyolefins differ significantly, resulting in weak interfacial bonding between the two. This can easily cause the inorganic materials to fall off the polyolefin separator during battery use, affecting the separator's stability and service life.

[0039] Based on this, the present application provides a diaphragm that does not contain polyolefin.

[0040] In a first aspect of the present application, a diaphragm is provided, comprising carboxyl-modified diamond, an aluminate coupling agent, a carboxylate compound, and a binder in a mass ratio of (0.04-0.06): (0.8-1.2): (0.2-0.3): (0.4-0.6).

[0041] The carboxylic acid ester compound includes one or more compounds having the structure shown in formula (I):

[0042] .

[0043] Compared to conventional inorganic oxide materials, diamond clusters possess advantages such as large surface area, high porosity, excellent heat dissipation, and a rich array of surface functional groups. These advantages offer broad potential for their application in membrane materials. However, the direct application of nanodiamonds in polymer-containing membranes still faces numerous challenges, including achieving uniform dispersion of the nanodiamonds and polymers, optimizing the structure and morphology of the membrane material, and identifying mechanisms for enhancing electrochemical performance.

[0044] This application uses carboxyl-modified diamond, which has good compatibility with components such as aluminate coupling agents, carboxylate compounds, and binders, thereby overcoming the disadvantage of insufficient dispersion uniformity of inorganic materials. Furthermore, the separator provided in this application includes carboxyl-modified diamond, aluminate coupling agents, carboxylate compounds, and binders in specific mass ratios. The aluminate coupling agent can form a chemical bond between the carboxyl-modified diamond and the binder, enhancing the bonding force and strength between the components. The carboxylate compound with a specific structure synergizes with the carboxyl-modified diamond to adjust the mechanical properties of the separator. The addition of a binder further increases the internal bonding force of the separator and makes the separator structure more stable, which helps prevent separator rupture and damage during the battery's charge and discharge processes, thereby ensuring battery stability. Furthermore, the polar groups of the carboxylate compound and the organic groups of the aluminate coupling agent can interact with the polarity analysis in the electrolyte or the organic solvent in the electrolyte to enhance the separator's affinity for the electrolyte, thereby improving the separator's wettability.

[0045] In summary, the diaphragm provided in this application can effectively improve the wettability and interfacial properties of the diaphragm and improve the electrochemical properties of the secondary battery, such as capacity, coulombic efficiency, and cycle stability, by selecting a specific mass ratio of carboxyl-modified diamond, aluminate coupling agent, carboxylate compound, and binder.

[0046] It is understood that in the present application, the mass ratio of carboxyl-modified diamond, aluminate coupling agent, carboxylate compound and binder can be selected from any value between (0.04-0.06): (0.8-1.2): (0.2-0.3): (0.4-0.6). Specifically, the mass ratio of carboxyl-modified diamond, aluminate coupling agent, carboxylate compound and binder includes but is not limited to 0.04:0.8:0.25:0.5, 0.045:0.8:0.25:0.5, 0.05:0.8:0.25:0.5, 0.053:0.8:0.25:0.5, 0.054:0.8:0.25:0.5, 0.060:0.8:0.25:0.5, 0.061:0.8:0.25:0.5, 0.062:0.8:0.25:0.5, 0.063:0.8:0.25:0.5, 0.064:0.8:0.25:0.5, 0.065:0.8:0.25:0.5, 0.066:0.8:0.25:0.5, 0.067:0.8:0.25:0.5, 0.068:0.8:0.25:0.5, 0.070:0.8:0.25:0.5, 0.071:0.8:0.25:0.5, 0.072:0.8:0.25:0.5 .055: 0.8: 0.25: 0.5, 0.058: 0.8: 0.25: 0.5, 0.06: 0.8: 0.25: 0.5, 0.04: 0.9: 0.25: 0.5, 0.045: 0.9: 0.25: 0.5, 0.05: 0.9: 0.25: 0.5, 0.053: 0.9: 0.25: 0.5, 0.054: 0.9: 0.25: 0.5, 0.055: 0.9: 0.25: 0.5, 0.058: 0.9: 0.25: 0.5, 0.06: 0.9: 0.25: 0.5, 0.04: 1: 0.25: 0.5, 0.045: 1: 0.25: 0.5, 0.05: 1: 0.25: 0.5, 0.053: 1: 0.25: 0.5 , 0.054:1:0.25:0.5, 0.055:1:0.25:0.5, 0.058:1:0.25:0.5, 0.06:1:0.25:0.5, 0.06:1:0.25:0.5, 0.06:1:0.25:0.55, 0.06:1:0.25:0.6 or 0.06:1.2:0.3:0.6, or the range consisting of the above two point values ​​as end values.

[0047] In one example, R 11 and R 12 Each independently selected from C3~C 10 Alkyl or C3~C 10 Halogenated alkyl.

[0048] Furthermore, R 11 and R 12 Each independently selected from C3~C 10 Alkyl or C3~C 10 Halogenated alkyl.

[0049] Furthermore, R 11 and R 12 Each is independently selected from C3 to C8 alkyl. For example, R 11 and R 12 Each is independently selected from -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2CH2-, or -CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2-.

[0050] In one example, Ar is selected from S1 substituted or unsubstituted C6~C 20 Arylene; S1 is selected from C1~C 10 Alkyl, C1~C 10 haloalkyl or . R 13 Selected from C3~C 10 Alkyl or C3~C 10 For example, Ar is selected from 、 、 、 、 or .

[0051] Further, Ar is selected from C6~C 10 Aromatic group.

[0052] Furthermore, Ar is selected from .

[0053] In one example, the carboxylic acid ester compound includes one or more compounds having the structure shown in formula (II): ; m1 and m2 are each independently 1, 2, 3, 4 or 5.

[0054] Furthermore, the carboxylic acid ester compound includes 、 、 、 and One or more of .

[0055] For example, the carboxylic acid ester compound includes 、 、 、 、 、 、 、 and One or more of .

[0056] The above-mentioned carboxylic acid ester compounds are supplemented with carboxyl-modified diamonds, which can improve the mechanical properties of the diaphragm and make the diaphragm easy to form while maintaining a certain strength. Specifically, the π-π stacking of the aromatic groups in the structure can enhance the interaction between the components and structures inside the diaphragm, thereby improving the mechanical strength of the diaphragm. In addition, the ester groups contained therein can chemically cross-link with the functional groups on the surface of the carboxyl-modified diamond, or the ester groups contained therein can bind to the surface of the carboxyl-modified diamond through hydrogen bonding interactions, which not only enhances the cohesion of the diaphragm material, but also helps to construct a barrier that is conducive to the migration of lithium ions but blocks the direct passage of electrons, thereby enhancing the overall stability of the diaphragm.

[0057] Furthermore, the ester groups in these carboxylic acid ester compounds impart good thermal stability and low volatility to the separator. Furthermore, the polar ester groups interact with polar molecules in the electrolyte, helping to form a stable SEI (solid electrolyte interface) layer, reducing side reactions and thus improving the battery's Coulombic efficiency. Furthermore, the alkyl side chains increase the molecular flexibility and help regulate the wettability of the separator material with the electrolyte, ensuring proper ion conduction without causing liquid leakage.

[0058] In one example, the aluminate coupling agent includes one or more of aluminate coupling agent LS60, aluminate coupling agent LS62, aluminate coupling agent LS821, and aluminate coupling agent NXH-821.

[0059] Based on extensive experience and extensive experimentation, the inventors of this application have discovered that the type of coupling agent plays a significant role in the compatibility of the various components in the diaphragm. Other coupling agents, such as aminosilanes, have the disadvantage of insufficient diaphragm stability when used in combination with carboxyl-modified diamond. Aluminate coupling agents hydrolyze or contain functional groups that can hydrolyze to form Al-O bonds, which allows them to react with the carboxyl groups in carboxyl-modified diamond to adjust their compatibility with the carboxyl-modified diamond. Furthermore, aluminate coupling agents contain long-chain alkyl or other organic end groups, which can also enhance their compatibility with organic binders.

[0060] In one example, the binder includes one or more of polyvinylidene fluoride, styrene-butadiene rubber, and carboxymethyl cellulose.

[0061] Furthermore, the binder includes polyvinylidene fluoride. The rational use of the polyvinylidene fluoride binder not only enhances the internal bonding force of the diaphragm, making the diaphragm structure more solid, but also improves the overall stability of the diaphragm.

[0062] In one example, the steps of preparing the carboxyl-modified diamond include:

[0063] Heat-treating the nanodiamond in air or oxygen environment to prepare the carboxyl-modified diamond;

[0064] Wherein, the surface of the nano-diamond has one or more of hydroxyl, carbonyl and carboxyl functional groups.

[0065] Heat treatment of nanodiamonds with one or more of the following functional groups: hydroxyl, carbonyl, and carboxyl groups, can further activate the carboxyl groups and promote their conversion to carboxyl groups. Heat treatment also helps remove impurities from the nanodiamond surface and promotes oxidation, thereby introducing more oxygen-containing functional groups.

[0066] In one example, the process parameters of the heat treatment include: heating to 400°C~450°C at a heating rate of 3°C / min~5°C / min, and keeping warm for 4h~10h.

[0067] It is understood that the heating rate in the heat treatment step can be selected from any value between 3°C / min and 5°C / min. For example, the heating rate includes but is not limited to 3°C / min, 3.5°C / min, 4°C / min, 4.5°C / min, or 5°C / min. The holding temperature includes but is not limited to 400°C, 410°C, 420°C, 430°C, 440°C, or 450°C. The holding time includes but is not limited to 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours.

[0068] In the present application, the source of nanodiamonds can be commercially available or homemade, as long as the nanodiamond surface has one or more of hydroxyl, carbonyl and carboxyl functional groups.

[0069] For example, the steps for preparing nanodiamonds in this application include:

[0070] a1. Take the carbon source trinitrotoluene and the pressurizing agent cyclotrimethylene trinitramine in a mass ratio of (70-40): (30-60) to obtain the explosive.

[0071] a2. Detonate the object to be exploded in a sealed explosion chamber filled with a cooling medium, wherein the ratio of the volume of the object to be exploded to the volume of the sealed explosion chamber is (0.1-0.5):1; prepare black powder.

[0072] a3. Heat-treating the black powder with hydrochloric acid to remove metal impurities in the black powder and removing graphite and carbon by oxidation to prepare the nanodiamond.

[0073] It is understood that the above-mentioned oxide can be oxidized using either a liquid-phase or vapor-phase method. During the oxidation process, the black powder gradually changes from black to light gray, resulting in light gray nanodiamond powder. Infrared spectroscopy reveals that the diamond surface produced by this preparation method has a variety of oxygen-containing functional groups. These include hydroxyl, carbonyl, carboxyl, ester, and ether groups. The oxygen-containing functional groups cover 10% to 20% of the nanodiamond surface area.

[0074] In one example, the thickness of the diaphragm is 150 μm to 500 μm. For example, the thickness of the diaphragm includes but is not limited to 150 μm, 180 μm, 200 μm, 220 μm, 240 μm, 260 μm, 280 μm, 300 μm, 330 μm, 350 μm, 380 μm, 400 μm, 430 μm, 450 μm, 480 μm, or 500 μm.

[0075] In a second aspect of the present application, there is provided a method for preparing the diaphragm described in any example of the first aspect of the present application, comprising the following steps:

[0076] S10, mixing the carboxyl-modified diamond, the aluminate coupling agent, the carboxylate compound, and the binder in a solvent to prepare a mixed slurry;

[0077] S20, forming the mixed slurry into a film, and drying it to prepare the separator.

[0078] In one example, in step b1, the carboxyl-modified diamond, the aluminate coupling agent, the carboxylate compound, and the binder are mixed in a solvent to prepare a mixed slurry, comprising:

[0079] b1. mixing the carboxyl-modified diamond and the aluminate coupling agent in a first solvent to prepare a first mixed solution;

[0080] b2. mixing the binder with a second solvent to prepare a second mixed solution;

[0081] b3. Mix the first mixed solution and the second mixed solution, add the carboxylate compound and mix to prepare a mixed slurry.

[0082] It is understood that the mixing in each step can be independently performed at room temperature or under heating conditions. For example, the process parameters for mixing under heating conditions include: heating to 40°C to 70°C for mixing.

[0083] For example, in step b3, the process parameters for adding the carboxylate compound and mixing include: mixing at 55° C. to 65° C.

[0084] In one example, the mass-to-volume ratio of the aluminate coupling agent to the solvent in the mixed slurry is (0.005-0.1) g:1 mL. The mass-to-volume ratio of the aluminate coupling agent to the solvent in the mixed slurry includes, but is not limited to, 0.007 g:1 mL, 0.008 g:1 mL, 0.009 g:1 mL, 0.01 g:1 mL, 0.011 g:1 mL, 0.015 g:1 mL, 0.02 g:1 mL, 0.04 g:1 mL, 0.06 g:1 mL, 0.08 g:1 mL, or 0.1 g:1 mL.

[0085] In the preparation method of the present application, the amount of solvent used and the heating treatment temperature of the nanodiamond are both reduced, which effectively reduces energy consumption and reduces the incorporation of impurities.

[0086] In one example, the solvent, the first solvent, and the second solvent are each independently selected from one or more of N-methylpyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide.

[0087] In one example, the mixed slurry is formed into a film and dried, and the step of preparing the diaphragm includes: coating the mixed slurry on the surface of the substrate and drying it to prepare the diaphragm.

[0088] In one example, the method for preparing the diaphragm further includes:

[0089] The substrate loaded with the diaphragm is immersed in water, and after the diaphragm is separated from the substrate, a drying process is performed.

[0090] Furthermore, the method for preparing the diaphragm provided in the present application comprises the following steps:

[0091] S100, heat-treating the nanodiamond in an air or oxygen environment to prepare the carboxyl-modified diamond; wherein the surface of the nanodiamond has one or more of hydroxyl, carbonyl and carboxyl functional groups; the process parameters of the heat treatment include: heating to 400°C~450°C at a heating rate of 3°C / min~5°C / min, and keeping the temperature for 4h~10h.

[0092] S200 , mixing the carboxyl-modified diamond and the aluminate coupling agent in a first solvent to prepare a first mixed solution.

[0093] S300: Mix the binder with a second solvent to prepare a second mixed solution.

[0094] S400: Mix the first mixed liquid and the second mixed liquid, add a carboxylate compound and mix, to prepare a mixed slurry.

[0095] S500, coating the mixed slurry on the surface of a substrate, and drying it to prepare the diaphragm.

[0096] S600: Soaking the substrate loaded with the diaphragm in water, and performing a drying process after the diaphragm is separated from the substrate.

[0097] In a third aspect of the present application, a secondary battery is provided, comprising a positive electrode sheet, a negative electrode sheet, a separator separated between the positive electrode sheet and the negative electrode sheet, and an electrolyte; the separator is the separator described in any example of the first aspect of the present application.

[0098] For example, the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material, a positive electrode binder, and a positive electrode conductor.

[0099] The positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate made of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0100] For example, the positive electrode active material is not limited to lithium iron phosphate (LiFePO4), lithium manganese phosphate (LiMnPO4), lithium cobalt phosphate (LiCoPO4), iron pyrophosphate (Li2FeP2O7), lithium cobalt oxide (LiCoO2), spinel lithium manganese oxide (LiMn2O4), spinel lithium nickel manganese oxide (LiNi 0.5 Mn 1.5 O4), layered lithium manganate (LiMnO2), lithium nickelate (LiNiO2), lithium niobate (LiNbO2), lithium ferrite (LiFeO2), lithium magnesium oxide (LiMgO2), lithium calcium oxide (LiCaO2), lithium cuprate (LiCuO2), lithium zincate (LiZnO2), lithium molybdate (LiMoO2) and lithium tantalate (LiTaO2).

[0101] For example, the positive electrode binder includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.

[0102] For example, the positive electrode conductive agent includes one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0103] The negative electrode sheet includes a negative electrode current collector and a negative electrode film layer provided on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material, a negative electrode conductive agent and a negative electrode binder.

[0104] For example, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer base layer (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0105] Illustratively, the negative electrode active material includes one or more of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate.

[0106] Illustratively, the negative electrode binder includes one or more of styrene-butadiene rubber, polyacrylic acid, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, sodium alginate, polymethacrylic acid, and carboxymethyl chitosan.

[0107] Illustratively, the negative electrode conductive agent includes one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0108] The electrolyte can be in liquid, gel or solid state.

[0109] In one example, the electrolyte is an electrolyte solution comprising a lithium salt and a solvent.

[0110] In one example, the lithium salt includes one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0111] In one example, the solvent includes one or more of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0112] In a fourth aspect of the present application, an electrical device is provided, comprising the secondary battery described in the third aspect of the present application.

[0113] The following further specific examples are provided to illustrate the present application in detail. It should also be understood that the following examples are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present application belong to the scope of protection of the present application. The specific process parameters and the like in the following embodiments are only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not necessarily limited to the specific values ​​of the embodiments below.

[0114] [raw material]

[0115] The nanodiamond preparation method includes: preparing a carbon source, trinitrotoluene, and a pressurizing agent, cyclotrimethylene trinitramine, in a mass ratio of 70:30 to produce an explosive. The explosive is then detonated in a sealed explosion chamber containing a cooling medium, with the volume ratio of the explosive to the sealed explosion chamber being 0.5:1. Black powder is then prepared; the black powder is then heated with hydrochloric acid to remove metallic impurities. Graphite and carbon are then removed by oxidation to produce nanodiamonds. The nanodiamond surface possesses oxygen-containing functional groups such as hydroxyl, carbonyl, carboxyl, ester, and ether groups.

[0116] Aluminate coupling agent: Model: Aluminate coupling agent LS821, purchased from: Hubei Longxin Chemical Industry Co., Ltd.;

[0117] Carboxylic acid ester compounds: dibutyl phthalate .

[0118] Example 1

[0119] Preparation of carboxyl-modified diamond: Nanodiamond powder was evenly spread in a porcelain boat to ensure uniform heat treatment. This apparatus was placed in a small tubular furnace and, under air, gradually heated to 425°C at a rate of 3°C / min. This temperature was maintained for 5 hours before naturally cooling to room temperature to produce carboxyl-modified diamond.

[0120] Preparation of mixed slurry:

[0121] (1) 0.0533 g of carboxyl-modified diamond was mixed in 50 mL of N-methylpyrrolidone solvent, and then 1 g of aluminate coupling agent LS821 was added. The mixture was ultrasonically mixed for 30 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing the first mixed solution.

[0122] (2) 0.5065 g of polyvinylidene fluoride was mixed with 50 mL of N-methylpyrrolidone solvent and ultrasonically mixed for 30 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing a second mixed solution.

[0123] (3) The first mixed solution and the second mixed solution were mixed, and 0.25 g of dibutyl phthalate was added. The mixture was placed in an oven at 60°C and dissolved for 10 minutes to prepare a mixed slurry.

[0124] Preparation of diaphragm:

[0125] The mixed slurry was evenly coated on a clean glass substrate using a 300 μm scraper, and then placed in an 80°C oven to dry for 4 hours to remove the solvent. After drying, the sample was immersed in deionized water for 40 minutes to separate it from the substrate, i.e., to remove the membrane. After that, the membrane was placed in a vacuum oven to dry to completely remove the residual moisture to complete the preparation of the membrane. The scanning electron microscope image of the membrane prepared in Example 1 is as follows: Figure 1 shown.

[0126] Example 2

[0127] Preparation of carboxyl-modified diamond: Nanodiamond powder was evenly spread in a porcelain boat to ensure uniform heat treatment. This apparatus was placed in a small tubular furnace and gradually heated to 425°C at a rate of 5°C / min. This temperature was maintained for 5 hours before being naturally cooled to room temperature to produce carboxyl-modified diamond.

[0128] Preparation of mixed slurry:

[0129] (1) 0.0598 g of carboxyl-modified diamond was mixed in 50 mL of N-methylpyrrolidone solvent, and then 0.9 g of aluminate coupling agent LS821 was added. The mixture was ultrasonically mixed for 40 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 5 minutes to ensure uniform mixing, thereby preparing the first mixed solution.

[0130] (2) 0.5086 g of polyvinylidene fluoride was mixed with 50 mL of N-methylpyrrolidone solvent and ultrasonically mixed for 40 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 5 minutes to ensure uniform mixing, thereby preparing a second mixed solution.

[0131] (3) The first mixed solution and the second mixed solution were mixed, and 0.27 g of dibutyl phthalate was added. The mixture was placed in an oven at 60°C and dissolved for 10 minutes to prepare a mixed slurry.

[0132] Preparation of diaphragm:

[0133] Use a 250μm scraper to evenly coat the mixed slurry on a clean glass substrate, and then place it in an 80℃ oven to dry for 4 hours to remove the solvent. After drying, immerse the sample in deionized water for 50 minutes to separate it from the substrate, i.e., demolding. After that, place the diaphragm in a vacuum oven to dry it to completely remove the residual moisture to complete the preparation of the diaphragm. The actual picture of the diaphragm prepared in Example 2 is as follows: Figure 2 shown.

[0134] Example 3

[0135] Preparation of carboxyl-modified diamond: Nanodiamond powder was evenly spread in a porcelain boat to ensure uniform heat treatment. This apparatus was placed in a small tubular furnace and gradually heated to 425°C at a rate of 3°C / min. This temperature was maintained for 5 hours before being naturally cooled to room temperature to produce carboxyl-modified diamond.

[0136] Preparation of mixed slurry:

[0137] (1) 0.0502 g of carboxyl-modified diamond was mixed in 50 mL of N-methylpyrrolidone solvent, and then 1 g of aluminate coupling agent LS821 was added. The mixture was ultrasonically mixed for 50 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing the first mixed solution.

[0138] (2) 0.4990 g of polyvinylidene fluoride was mixed with 50 mL of N-methylpyrrolidone solvent and ultrasonically mixed for 50 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing a second mixed solution.

[0139] (3) The first mixed solution and the second mixed solution were mixed, and 0.24 g of dibutyl phthalate was added. The mixture was placed in an oven at 60°C and dissolved for 10 minutes to prepare a mixed slurry.

[0140] Preparation of diaphragm:

[0141] The mixed slurry was evenly coated onto a clean glass substrate using a 400μm scraper and then dried in an 80°C oven for 4 hours to remove the solvent. After drying, the sample was immersed in deionized water for 50 minutes to separate it from the substrate, a process known as demolding. The membrane was then dried in a vacuum oven to completely remove any residual moisture, completing the membrane preparation.

[0142] Example 4

[0143] Preparation of carboxyl-modified diamond: Nanodiamond powder was evenly spread in a porcelain boat to ensure uniform heat treatment. This apparatus was placed in a small tubular furnace and gradually heated to 425°C at a rate of 5°C / min. This temperature was maintained for 5 hours before being naturally cooled to room temperature to produce carboxyl-modified diamond.

[0144] Preparation of mixed slurry:

[0145] (1) 0.0507 g of carboxyl-modified diamond was mixed in 50 mL of N-methylpyrrolidone solvent, and then 0.8 g of aluminate coupling agent LS821 was added. The mixture was ultrasonically mixed for 40 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 5 minutes to ensure uniform mixing, thereby preparing the first mixed solution.

[0146] (2) 0.4985 g of polyvinylidene fluoride was mixed with 50 mL of N-methylpyrrolidone solvent and ultrasonically mixed for 40 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 5 minutes to ensure uniform mixing, thereby preparing a second mixed solution.

[0147] (3) The first mixed solution and the second mixed solution were mixed, and 0.26 g of dibutyl phthalate was added. The mixture was placed in an oven at 60°C and dissolved for 10 minutes to prepare a mixed slurry.

[0148] Preparation of diaphragm:

[0149] The mixed slurry was evenly coated onto a clean glass substrate using a 450μm scraper and then dried in an 80°C oven for 4 hours to remove the solvent. After drying, the sample was immersed in deionized water for 50 minutes to separate it from the substrate, a process known as demolding. The membrane was then dried in a vacuum oven to completely remove any residual moisture, completing the membrane preparation.

[0150] Comparative Example 1

[0151] Preparation of mixed slurry:

[0152] Prepare a mixed solution by mixing 0.5g of polyvinylidene fluoride with 50mL of N-methylpyrrolidone solvent and ultrasonically mixing for 30 minutes. Every 10 minutes, manually shake the mixture for 3 minutes to ensure uniform mixing. Add 0.26g of dibutyl phthalate and dissolve in a 60°C oven for 10 minutes to prepare a mixed slurry.

[0153] Preparation of diaphragm:

[0154] The mixed slurry was evenly coated onto a clean glass substrate using a 300μm scraper and then dried in an 80°C oven for 4 hours to remove the solvent. After drying, the sample was immersed in deionized water for 30 minutes to separate it from the substrate, a process known as demolding. The membrane was then dried in a vacuum oven to completely remove any residual moisture, completing the membrane preparation.

[0155] Comparative Example 2

[0156] Preparation of mixed slurry:

[0157] (1) 0.0533 g of carboxyl-modified diamond powder was mixed with 50 mL of N-methylpyrrolidone solvent, and then 1 g of coupling agent γ-aminopropyltriethoxysilane was added. The mixture was ultrasonically mixed for 30 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing the first mixed solution.

[0158] (2) 0.5065 g of polyvinylidene fluoride was mixed with 50 mL of N-methylpyrrolidone solvent and ultrasonically mixed for 30 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing a second mixed solution.

[0159] (3) The first mixed solution and the second mixed solution were mixed, and 0.25 g of dibutyl phthalate was added. The mixture was placed in an oven at 60°C and dissolved for 10 minutes to prepare a mixed slurry.

[0160] Preparation of diaphragm:

[0161] The mixed slurry was evenly coated onto a clean glass substrate using a 300μm scraper and then dried in an 80°C oven for 4 hours to remove the solvent. After drying, the sample was immersed in deionized water for 40 minutes to separate it from the substrate, a process known as demolding. The membrane was then dried in a vacuum oven to completely remove any residual moisture, completing the membrane preparation.

[0162] Comparative Example 3

[0163] Preparation of carboxyl-modified diamond: Nanodiamond powder was evenly spread in a porcelain boat to ensure uniform heat treatment. This apparatus was placed in a small tubular furnace and gradually heated to 425°C at a rate of 3°C / min. This temperature was maintained for 5 hours before being naturally cooled to room temperature to produce carboxyl-modified diamond.

[0164] Preparation of mixed slurry:

[0165] (1) 0.0533 g of carboxyl-modified diamond was mixed in 50 mL of N-methylpyrrolidone solvent, and then 1 g of aluminate coupling agent LS821 was added. The mixture was ultrasonically mixed for 30 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing the first mixed solution.

[0166] (2) 0.5065 g of polyvinylidene fluoride was mixed with 50 mL of N-methylpyrrolidone solvent and ultrasonically mixed for 30 minutes. During this period, the system was taken out every 10 minutes and manually shaken for 3 minutes to ensure uniform mixing, thereby preparing a second mixed solution.

[0167] (3) The first mixed solution and the second mixed solution were mixed, and 0.25 g of plasticizer epoxy tetrahydrophthalate dioctyl ester was added, and the mixture was placed in an oven at 60°C for 10 minutes to dissolve to prepare a mixed slurry.

[0168] Preparation of diaphragm:

[0169] The mixed slurry was evenly coated onto a clean glass substrate using a 300μm scraper and then dried in an 80°C oven for 4 hours to remove the solvent. After drying, the sample was immersed in deionized water for 40 minutes to separate it from the substrate, a process known as demolding. The membrane was then dried in a vacuum oven to completely remove any residual moisture, completing the membrane preparation.

[0170] Test Case

[0171] Contact angle: The contact angle performance of the membrane and the electrolyte was measured using an electrolyte solution containing 1 mol / L LiPF6, 89 vol% DEC / EC (1:1), 1 vol% VC, and 10% FEC additives using a German Kruss DSA100 video optical contact angle meter. The contact angle performance of the membrane prepared in Example 3 and the electrolyte is shown in the figure below. Figure 3 shown.

[0172] Cycling performance: The diaphragms prepared in Example 1 and Comparative Example 1 were assembled into silicon negative electrode half-cells, and the cycling performance of the silicon negative electrode half-cells was tested at a charge and discharge rate of 0.5C. Figure 4 shown.

[0173] Depend on Figure 1 It can be seen that the diaphragm prepared in this application still has good porosity without adding polyolefin. Figure 3 It can be seen that the diaphragm prepared in this application has good wettability with the electrolyte. Figure 4 When the diaphragm prepared in Example 1 is assembled into a silicon negative electrode half-cell, it has more excellent specific capacity and coulombic efficiency, and its cycle stability is more excellent.

[0174] Figure 5 This is a real shot of the diaphragm prepared in Comparative Example 2. Figure 6 This is a real shot of the diaphragm prepared in Comparative Example 3. Figure 5 and Figure 6 It can be seen that the diaphragm prepared in Comparative Example 2 did not use an aluminate coupling agent, and the diaphragm prepared in Comparative Example 3 did not use a carboxylate compound, resulting in poor mechanical properties of the diaphragms prepared in Comparative Examples 2 and 3, which are shown in the actual photos as being fragile.

[0175] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0176] The embodiments described above only express several implementation methods of the present application, which are convenient for understanding the technical solutions of the present application in a specific and detailed manner, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all fall within the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A diaphragm, characterized in that: The diaphragm comprises carboxyl-modified diamond, an aluminate coupling agent, a carboxylate compound, and a binder in a mass ratio of (0.04-0.06): (0.8-1.2): (0.2-0.3): (0.4-0.6); The carboxylic acid ester compound includes one or more compounds having the structure shown in formula (II): ; m1 and m2 are each independently 1, 2, 3, 4 or 5; The aluminate coupling agent includes one or more of aluminate coupling agent LS60, aluminate coupling agent LS62, aluminate coupling agent LS821 and aluminate coupling agent NXH-821.

2. The diaphragm according to claim 1, characterized in that The binder includes one or more of polyvinylidene fluoride, styrene-butadiene rubber and carboxymethyl cellulose.

3. The diaphragm according to claim 1 or 2, characterized in that The preparation steps of the carboxyl-modified diamond include: Heat-treating the nanodiamond in air or oxygen environment to prepare the carboxyl-modified diamond; The surface of the nanodiamond has one or more of hydroxyl, carbonyl and carboxyl functional groups; the process parameters of the heat treatment include: heating to 400°C~450°C at a heating rate of 3°C / min~5°C / min, and keeping warm for 4h~10h.

4. The diaphragm according to claim 3, characterized in that The preparation steps of the nanodiamond include: The carbon source trinitrotoluene and the pressurizing agent cyclotrimethylene trinitramine are taken in a mass ratio of (70-40): (30-60) to obtain the explosive; Detonating the object to be exploded in a sealed explosion chamber filled with a cooling medium, wherein the ratio of the volume of the object to be exploded to the volume of the sealed explosion chamber is (0.1-0.5):1; preparing black powder; The black powder is treated by heating with hydrochloric acid to remove metal impurities in the black powder, and graphite and carbon are removed by oxidation to prepare the nano-diamond.

5. The diaphragm according to claim 1 or 2, characterized in that The thickness of the separator is 150 μm to 500 μm.

6. The diaphragm according to claim 1 or 2, characterized in that The aluminate coupling agent forms a chemical bond between the carboxyl-modified diamond and the binder.

7. A method for preparing a diaphragm according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mixing the carboxyl-modified diamond, the aluminate coupling agent, the carboxylate compound, and the binder in a solvent to prepare a mixed slurry; The mixed slurry is formed into a film and dried to prepare the separator.

8. The method for preparing a diaphragm according to claim 7, characterized in that: In the mixed slurry, the mass volume ratio of the aluminate coupling agent to the solvent is (0.005-0.1) g:1 mL.

9. A secondary battery, characterized in that: The invention comprises a positive electrode sheet, a negative electrode sheet, a separator between the positive electrode sheet and the negative electrode sheet, and an electrolyte; wherein the separator is the separator according to any one of claims 1 to 6.

10. An electrical device, characterized in that: The secondary battery according to claim 9 is included.

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