A positive electrode material for improving the performance of an lmfp battery and a method for preparing the same

Abstract

The application discloses a positive electrode material for improving the performance of an LMFP battery and a preparation method thereof, and relates to the technical field of battery preparation. A button battery is assembled by using the positive electrode material, and the button battery comprises the following steps: (1) mixing the positive electrode material in claim 4 with an adhesive and a conductive agent, stirring uniformly, and obtaining a positive electrode slurry; (2) coating the positive electrode slurry on a 12 mu m aluminum foil, drying at 120 DEG C for 12 hours, and obtaining a positive electrode sheet; and (3) assembling according to the assembly sequence of "battery shell - placing the positive electrode sheet - adding electrolyte - placing the modified diaphragm - adding electrolyte - placing the lithium sheet - placing the gasket spring - battery shell", and obtaining the button battery. Advantages: the modified LMFP material is prepared by means of hydrothermal synthesis and calcination technology, and the diaphragm of the battery is further modified, so that the first charge-discharge efficiency and the rate performance of the battery are effectively improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery preparation, in particular to a positive electrode material for improving the performance of an LMFP battery and a preparation method thereof. BACKGROUND

[0002] In recent years, lithium iron phosphate (LFP) material gradually occupies the positive electrode material market of domestic power batteries due to its advantages of environmental protection, low cost, high safety performance and the like, but the limited voltage platform and poor low-temperature performance of the LFP material restrict the application of the LFP material.

[0003] Now, the introduction of manganese elements makes the voltage platform of the LFP originally 3.4V rise to 4.1V of the LMFP, and a breakthrough is made on the voltage platform. When the manganese-iron ratio is high, the voltage and energy density of the battery are significantly improved due to the high voltage platform of the manganese and the good conductivity of the iron, but the conductivity is greatly reduced, thereby affecting the rate performance. Therefore, how to improve the rate performance of the LMFP has become the top priority.

[0004] In summary, in order to solve the above problems, the application provides a positive electrode material for improving the performance of an LMFP battery and a preparation method thereof. SUMMARY

[0005] The application aims to provide a positive electrode material for improving the performance of an LMFP battery and a preparation method thereof to solve the problems in the prior art.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme.

[0007] A preparation method of a positive electrode material for improving the performance of an LMFP battery comprises the following steps.

[0008] Step 1: a traditional LMFP material and NaOH particles are dissolved in concentrated sulfuric acid, stirred uniformly, transferred to a reaction kettle, baked at 180 DEG C for 16h, and then filtered, washed and vacuum dried to obtain LMFP-Na.

[0009] Step 2: the LMFP-Na and LiF are mixed and mechanically ball milled, and then put into a tube furnace and calcined at 900 DEG C for 10h to obtain the positive electrode material.

[0010] More preferably, the mass ratio of the traditional LMFP material to the NaOH particles is (120-125):1, and the mass ratio of the traditional LMFP material to the LiF is (100-105):1.

[0011] More preferably, in the calcination process, the heating rate is 40 DEG C / min, and the annealing rate is 40 DEG C / min.

[0012] A method for manufacturing a button cell, comprising the following steps:

[0013] (1) mixing the obtained positive electrode material with a binder and a conductive agent, stirring uniformly to obtain a positive electrode slurry;

[0014] (2) coating the positive electrode slurry on a 12 mu m aluminum foil, drying at 120 DEG C for 12 h to obtain a positive electrode sheet;

[0015] (3) assembling according to the assembly sequence of "battery shell - placing the positive electrode sheet - adding electrolyte - placing the modified separator - adding electrolyte - placing lithium sheet - placing gasket spring - battery shell" to obtain a button cell.

[0016] More preferably, the preparation process of the modified separator is:

[0017] 1) polypropylene resin, modified halloysite nanotube, initiator and antioxidant are added into a double screw extruder, melt blending extrusion, cooling and setting, then longitudinal stretching and transverse stretching, setting, winding to obtain a film;

[0018] 2) zeolite powder is dispersed in a polyvinylidene fluoride solution, then coated on the film by dip coating to obtain a zeolite coating, and dried at room temperature to obtain a modified separator.

[0019] More preferably, the preparation process of the modified halloysite nanotube is:

[0020] S1: halloysite nanotubes are dispersed in methanol, ultrasonic treatment for 15-20 min, then gamma-glycidyl ether propyltrimethoxysilane is added dropwise, mixed and stirred at 75-80 DEG C for 3-4 h to obtain epoxidized halloysite nanotubes;

[0021] S2: amino-polyethylene glycol-carboxyl, aminated cage polysilsesquioxane is dissolved in chloroform, ultrasonic stirring for 1-2 h, 4-dimethylaminopyridine is added, heated to 60-70 DEG C, and reacted for 4-5 h, centrifuged, washed, and vacuum dried to obtain polyethylene glycol modified siloxane;

[0022] S3: polyethylene glycol modified siloxane and L-allylglycine are mixed and added to dimethyl sulfoxide, 4-dimethylaminopyridine is added, heated to 80-90 DEG C, and reacted for 7-8 h, then treated to obtain amino-alkenylated siloxane;

[0023] S4: amino-alkenylated siloxane and epoxidized halloysite nanotubes are added to tetrahydrofuran, stirred vigorously for 1-2 h, centrifuged, washed with tetrahydrofuran and deionized water, and the obtained powder is dried under vacuum for 12-15 h to obtain modified halloysite nanotubes.

[0024] More preferably, the epoxidized halloysite nanotube comprises the following components: 20-25 parts of halloysite nanotube, 150-200 parts of methanol, 0.1-0.2 parts of gamma-glycidoxypropyltrimethoxysilane by weight fraction;

[0025] The polyethylene glycol modified siloxane comprises the following components: 12-15 parts of amino-polyethylene glycol-carboxyl, 20-22 parts of aminated cage polysilsesquioxane, 100-150 parts of chloroform, 0.1-0.2 parts of 4-dimethylaminopyridine by weight fraction;

[0026] The amino-alkenylated siloxane comprises the following components: 12-15 parts of polyethylene glycol modified siloxane, 5-6 parts of L-allylglycine, 80-100 parts of dimethyl sulfoxide, 0.05-0.1 parts of 4-dimethylaminopyridine by weight fraction;

[0027] The modified halloysite nanotube comprises the following components: 12-15 parts of amino-alkenylated siloxane, 8-10 parts of epoxidized halloysite nanotube, 80-100 parts of tetrahydrofuran by weight fraction.

[0028] More preferably, the membrane comprises the following components: 50-60 parts of polypropylene resin, 5-8 parts of modified halloysite nanotube, 0.1-0.2 parts of initiator, 4-5 parts of antioxidant by weight fraction; the thickness of the zeolite coating is 2-4 microns.

[0029] More preferably, the membrane comprises the following components: the initiator comprises one of benzoyl peroxide and lauroyl peroxide; the antioxidant comprises one or more of hindered phenolic antioxidant and thioester antioxidant.

[0030] Compared with the prior art, the application has the following beneficial effects:

[0031] The modified LMFP material is prepared by hydrothermal synthesis and calcination technology, and the separator of the battery is further modified, so that the first charge-discharge efficiency and the rate performance of the battery are effectively improved.

[0032] Firstly, the prepared positive electrode material has a larger ion radius Na + located at the Li site, effectively widening the Li + diffusion channel, improving the lithium ion transport kinetics, and thus improving the rate performance; and the F element has a stronger ionic bond form compared with the O element, and the F-M bond has a stronger binding energy than the O-M bond (M is a transition metal element), so the introduction of F - is more conducive to improving the ionic conductivity of the raw material, thereby improving the battery performance; at the same time, the Li +Also play a role in improving the first charge-discharge efficiency of LMFP battery;

[0033] Secondly: the hollow structure of the halloysite nanotube can provide additional adsorption sites, increase the absorption capacity of the membrane to the electrolyte, and can promote the uniform distribution of lithium ions, effectively inhibit the germination of lithium whiskers, and thus improve the first charge-discharge efficiency of the battery, but due to the poor dispersibility and compatibility of the halloysite nanotube in the matrix, the proportion of its introduction is limited.

[0034] Therefore, the present application firstly combines the silane coupling agent with the hydroxyl group on the surface of the halloysite nanotube to obtain an epoxidized halloysite nanotube, then reacts the carboxyl group of the amino-polyethylene glycol-carboxyl with the amino group of the aminated cage polysilsesquioxane under the action of the catalyst 4-dimethylaminopyridine to obtain a polyethylene glycol modified siloxane, then introduces a double bond by further reacting the L-allyl glycine with the amino group at the other end of the polyethylene glycol modified siloxane, and then mixing with the epoxidized halloysite nanotube, the amino group in the molecule can react with the epoxy group to obtain a modified halloysite nanotube.

[0035] Among them, the introduction of the polyethylene glycol segment improves the wettability of the diaphragm, and good diaphragm wettability is beneficial to the affinity between the electrolyte and the diaphragm, expands the contact area between the diaphragm and the electrolyte, thereby increasing the ion conductivity and providing sufficient channels for ion transmission, thereby providing smaller effective current density and increasing the rate performance of the battery; the introduction of the cage polysilsesquioxane segment also improves the thermal stability of the diaphragm; the double bond segment can also crosslink with the base polypropylene under the action of the initiator, improving the compatibility.

[0036] Thirdly: the zeolite coating can improve the wettability of the diaphragm to the electrolyte, which is crucial to the performance of the battery. The diaphragm with good wettability helps to fill the electrolyte during the assembly of the battery, effectively retains the electrolyte, and improves the conduction efficiency of lithium ions. DETAILED DESCRIPTION

[0037] Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0038] It should be noted that the following parts are parts by weight, and there is no special restriction on the purchase manufacturer of all raw materials involved in the present application, which exemplarily includes: in the following examples, the amino-polyethylene glycol-carboxyl CAS is 139729-28-5; the aminated cage polysilsesquioxane is Q-0000177; the L-allyl glycine CAS is 195316-72-4; and the gamma-glycidyl ether oxypropyl trimethoxysilane CAS is 2530-83-8.

[0039] Example 1: A preparation method of a button cell, comprising the following steps:

[0040] (1) The positive electrode material obtained above is mixed with PVDF and Super P, and stirred uniformly to obtain a positive electrode slurry;

[0041] (2) The positive electrode slurry is coated on a 12 μm aluminum foil, which is dried at 120°C for 12 h to obtain a positive electrode sheet;

[0042] (3) The button cell is assembled according to the assembly sequence of "cell shell - placing the positive electrode sheet - adding electrolyte - placing the separator (polypropylene, 20 μm) - adding electrolyte - placing the lithium sheet - placing the gasket spring - cell shell";

[0043] The preparation process of the positive electrode material is as follows:

[0044] Step 1: The conventional LMFP material and NaOH particles are dissolved in concentrated sulfuric acid, stirred uniformly, and then transferred to a reaction kettle, which is baked at 180°C for 16 h, and then filtered, washed, and vacuum dried to obtain LMFP-Na;

[0045] Step 2: The LMFP-Na and LiF are mixed and mechanically ball milled, and then placed in a tube furnace and calcined at 900°C for 10 h to obtain the positive electrode material; the mass ratio of the conventional LMFP material to NaOH particles is 125:1; and the mass ratio of the conventional LMFP material to LiF is 105:1.

[0046] Example 2: The same as Example 1, except that the mass ratio of the conventional LMFP material to NaOH is 115:1.

[0047] Example 3: The same as Example 1, except that the mass ratio of the conventional LMFP material to NaOH is 120:1.

[0048] Example 4: The same as Example 1, except that the mass ratio of the conventional LMFP material to NaOH is 130:1.

[0049] Example 5: The same as Example 1, except that the mass ratio of the conventional LMFP material to NaOH is 135:1.

[0050] Example 6: The same as Example 1, except that the mass ratio of the conventional LMFP material to LiF is 95:1.

[0051] Example 7: The same as Example 1, except that the mass ratio of the conventional LMFP material to LiF is 100:1.

[0052] Example 8: substantially the same as Example 1, except that the mass ratio of the traditional LMFP material to LiF is 110:1.

[0053] Example 9: substantially the same as Example 1, except that the mass ratio of the traditional LMFP material to LiF is 115:1.

[0054] Comparative Example 1: substantially the same as Example 1, except that no NaOH is introduced in Step 1.

[0055] Comparative Example 2: substantially the same as Example 1, except that no LiF material is introduced in Step 1.

[0056] Comparative Example 3: substantially the same as Example 1, except that a traditional LMFP is used for the positive electrode material.

[0057] Comparative Example 4: an experiment is conducted by adding a modified separator, as follows:

[0058] A method for preparing a button cell, comprising the following steps:

[0059] (1) mixing the positive electrode material obtained above with PVDF and Super P, and stirring uniformly to obtain a positive electrode slurry;

[0060] (2) coating the positive electrode slurry on a 12 μm aluminum foil, and drying at 120°C for 12 h to obtain a positive electrode sheet;

[0061] (3) assembling according to the assembly sequence of "cell shell - placing the positive electrode sheet - adding electrolyte - placing the modified separator (polypropylene, 20 μm) - adding electrolyte - placing the lithium sheet - placing the gasket spring - cell shell", to obtain a button cell;

[0062] The preparation process of the positive electrode material is as follows:

[0063] Step 1: dissolving the traditional LMFP material and NaOH particles in concentrated sulfuric acid, stirring uniformly, and then transferring to a reaction kettle, and baking at 180°C for 16 h, and then filtering, washing, and vacuum drying to obtain LMFP-Na;

[0064] Step 2: mixing LMFP-Na and LiF, and then mechanically ball milling, and then placing in a tube furnace, and calcining at 900°C for 10 h to obtain a positive electrode material; the mass ratio of the traditional LMFP material to NaOH particles is 125:1; and the mass ratio of the traditional LMFP material to LiF is 105:1.

[0065] The preparation process of the modified separator is as follows:

[0066] 1): 50 parts of polypropylene resin, 5 parts of modified halloysite nanotube, 0.1 part of initiator and 4 parts of antioxidant were added into a twin-screw extruder, melt blended and extruded, cooled and shaped, then longitudinally stretched and transversely stretched, shaped, and wound to obtain a film sheet;

[0067] 2): zeolite powder was dispersed in a polyvinylidene fluoride solution, then coated on the film sheet by dip coating to obtain a zeolite coating layer, and dried at room temperature to obtain a modified separator;

[0068] The preparation process of the modified halloysite nanotube is as follows:

[0069] S1: 20 parts of halloysite nanotube were dispersed in 150 parts of methanol, ultrasonically treated for 20 min, then 0.1 part of γ-glycidyloxypropyltrimethoxysilane was added dropwise, mixed, and stirred at 80°C for 4 h to obtain epoxidized halloysite nanotube;

[0070] S2: 12 parts of amino-polyethylene glycol-carboxyl and 20 parts of aminated cage polysilsesquioxane were dissolved in 100 parts of chloroform, ultrasonically stirred for 2 h, 0.1 part of 4-dimethylaminopyridine was added, the temperature was raised to 70°C, and the reaction was carried out for 5 h, then centrifuged, washed, and vacuum dried to obtain polyethylene glycol modified siloxane;

[0071] S3: 12 parts of polyethylene glycol modified siloxane and 5 parts of L-allylglycine were mixed and added to 80 parts of dimethyl sulfoxide, 0.05 parts of 4-dimethylaminopyridine was added, the temperature was raised to 90°C, and the reaction was carried out for 8 h, then post-treated to obtain amino-alkenylated siloxane;

[0072] S4: 12 parts of amino-alkenylated siloxane and 8 parts of epoxidized halloysite nanotube were added to 80 parts of tetrahydrofuran, and stirred vigorously for 2 h, then centrifuged, washed with tetrahydrofuran and deionized water, and the obtained powder was dried under vacuum for 15 h to obtain modified halloysite nanotube.

[0073] Comparative Example 5: halloysite nanotube was not modified, and the rest was the same as Comparative Example 4, and the preparation process of a modified separator was as follows:

[0074] 1): 50 parts of polypropylene resin, 5 parts of halloysite nanotube, and 4 parts of antioxidant were added into a twin-screw extruder, melt blended and extruded, cooled and shaped, then longitudinally stretched and transversely stretched, shaped, and wound to obtain a film sheet;

[0075] 2): zeolite powder was dispersed in a polyvinylidene fluoride solution, then coated on the film sheet by dip coating to obtain a zeolite coating layer, and dried at room temperature to obtain a modified separator.

[0076] Comparative Example 6: no zeolite coating layer was added, and the rest was the same as Comparative Example 4, and the preparation process was as follows:

[0077] A preparation process of a modified separator is as follows:

[0078] 1) 50 parts of polypropylene resin, 5 parts of modified halloysite nanotubes, 0.1 part of initiator and 4 parts of antioxidant are added into a double screw extruder, melt blended and extruded, cooled and shaped, then longitudinally stretched and transversely stretched, shaped, and wound to obtain a modified separator;

[0079] The preparation process of the modified halloysite nanotubes is as follows:

[0080] S1: 20 parts of halloysite nanotubes are dispersed in 150 parts of methanol, ultrasonically treated for 20 min, then 0.1 part of γ-glycidyloxypropyltrimethoxysilane is added dropwise, mixed, and stirred at 80℃ for 4 h to obtain epoxidized halloysite nanotubes;

[0081] S2: 12 parts of amino-polyethylene glycol-carboxyl and 20 parts of aminated cage polysilsesquioxane are dissolved in 100 parts of chloroform, ultrasonically stirred for 2 h, 0.1 part of 4-dimethylaminopyridine is added, the temperature is raised to 70℃, and the reaction is carried out for 5 h, then centrifuged, washed, and vacuum dried to obtain polyethylene glycol modified siloxane;

[0082] S3: 12 parts of polyethylene glycol modified siloxane and 5 parts of L-allylglycine are mixed and added to 80 parts of dimethyl sulfoxide, 0.05 part of 4-dimethylaminopyridine is added, the temperature is raised to 90℃, and the reaction is carried out for 8 h, then post-treated to obtain amino-alkenylated siloxane;

[0083] S4: 12 parts of amino-alkenylated siloxane and 8 parts of epoxidized halloysite nanotubes are added to 80 parts of tetrahydrofuran, and stirred vigorously for 2 h, then centrifuged, washed with tetrahydrofuran and deionized water, and the obtained powder is dried under vacuum for 15 h to obtain modified halloysite nanotubes.

[0084] Comparative Example 7: Only the halloysite nanotubes are modified using a silane coupling agent, and the rest is the same as Comparative Example 4, which is as follows:

[0085] A preparation process of a modified separator is as follows:

[0086] 1) 50 parts of polypropylene resin, 5 parts of modified halloysite nanotubes, 0.1 part of initiator and 4 parts of antioxidant are added into a double screw extruder, melt blended and extruded, cooled and shaped, then longitudinally stretched and transversely stretched, shaped, and wound to obtain a film;

[0087] 2) The zeolite powder is dispersed in a polyvinylidene fluoride solution, then coated on the film by dip coating to obtain a zeolite coating, and dried at room temperature to obtain a modified separator;

[0088] The preparation process of the modified halloysite nanotubes is as follows:

[0089] S1: 20 parts of halloysite nanotubes were dispersed in 150 parts of methanol, ultrasonic treatment for 20 min, then 0.1 parts of γ-glycidyloxypropyltrimethoxysilane was added dropwise, mixed and stirred at 80°C for 4h to obtain epoxy halloysite nanotubes.

[0090] Test experiment: (1) The obtained button cell was tested for charge and discharge at 0.1C current by using a button cell charge and discharge tester (Wuhan LanDian, CT2001A), and the voltage range was 2.5-4.1V.

[0091] The obtained button cell was tested for charge and discharge at different rates (0.5C, 1C, 2C) by using a button cell charge and discharge tester (Wuhan LanDian, CT2001A), and the voltage range was 2.5-4.1V; the obtained data are shown in the following table:

[0092] Table 1

[0093]

[0094] Conclusion: The positive electrode material prepared by hydrothermal synthesis and calcination technology in Example 1 effectively improves the first charge and discharge efficiency and rate performance of the battery. On the basis of Comparative Example 4, the modified separator is added to further improve the first charge and discharge efficiency and rate performance of the battery. It meets the actual application.

[0095] Finally, it should be pointed out that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a cathode material to improve the performance of an LMFP battery, characterized in that: Includes the following steps: Step 1: Dissolve traditional LMFP material and NaOH particles in concentrated sulfuric acid, stir evenly, transfer to a reaction vessel, bake at 180-120℃ for 16-18 hours, then filter, wash, and vacuum dry to obtain LMFP-Na; Step 2: Mix LMFP-Na and LiF and then mechanically ball-mill them. Then place them in a tube furnace and calcine them at 900-950℃ for 10-12 hours to obtain the cathode material.

2. The method for preparing a cathode material for improving the performance of an LMFP battery according to claim 1, characterized in that: The mass ratio of the traditional LMFP material to NaOH particles is (120-125):1; the mass ratio of the traditional LMFP material to LiF is (100-105):

1.

3. The method for preparing a cathode material for improving the performance of an LMFP battery according to claim 1, characterized in that: During the calcination process, the heating rate is 40-45℃ / min, and the annealing rate is 40-45℃ / min.

4. A cathode material, characterized in that: The cathode material is obtained by the preparation method described in claim 1.

5. A method for preparing a button cell battery, characterized in that: Includes the following steps: (1) The positive electrode material described in claim 4 is mixed with a binder and a conductive agent, and stirred evenly to obtain a positive electrode slurry; (2) Coat the positive electrode slurry onto a 12-15μm aluminum foil and dry it at 120-130℃ for 12-15h to obtain the positive electrode sheet; (3) Assemble the battery according to the assembly sequence of "battery case - place positive electrode plate - add electrolyte - place modified separator - add electrolyte - place lithium plate - place gasket spring - battery case" to obtain the button battery; The preparation process of the modified diaphragm is as follows: 1): Polypropylene resin, modified halloysite nanotubes, initiator and antioxidant are added to a twin-screw extruder, melt-blended and extruded, cooled and shaped, then stretched longitudinally and transversely, shaped and wound to obtain a film; 2): Zeolite powder is dispersed in a polyvinylidene fluoride solution, and then coated onto a membrane by dip coating to obtain a zeolite coating. The coating is then dried at room temperature to obtain a modified membrane. The preparation process of the modified halloysite nanotubes is as follows: S1: Halloysite nanotubes were dispersed in methanol and sonicated for 15-20 min. Then, γ-glycidoxypropyltrimethoxysilane was added dropwise. After mixing, the mixture was stirred at 75-80℃ for 3-4 h to obtain epoxidized halloysite nanotubes. S2: Dissolve amino-polyethylene glycol-carboxyl and amino-cage-type polysilsesquioxane in chloroform, stir ultrasonically for 1-2 hours, add 4-dimethylaminopyridine, heat to 60-70℃, react for 4-5 hours, centrifuge, wash, and vacuum dry to obtain polyethylene glycol-modified siloxane. S3: Mix polyethylene glycol-modified siloxane and L-allyl glycine, add to dimethyl sulfoxide, add 4-dimethylaminopyridine, heat to 80-90℃, react for 7-8h, and then perform post-treatment to obtain amino-alkenylated siloxane. S4: Add amino-alkenylated siloxane and epoxidized halloysite nanotubes to tetrahydrofuran, stir vigorously for 1-2 hours, centrifuge, wash with tetrahydrofuran and deionized water, and dry the resulting powder under vacuum for 12-15 hours to obtain modified halloysite nanotubes.

6. The method for preparing a button cell according to claim 5, characterized in that: The epoxidized halloysite nanotubes comprise the following components: by weight, 20-25 parts halloysite nanotubes, 150-200 parts methanol, and 0.1-0.2 parts γ-glycidoxypropyltrimethoxysilane; The polyethylene glycol-modified siloxane comprises the following components: by weight, 12-15 parts amino-polyethylene glycol-carboxyl, 20-22 parts amino-modified cage-type polysilsesquioxane, 100-150 parts chloroform, and 0.1-0.2 parts 4-dimethylaminopyridine. The amino-alkenylated siloxane comprises the following components: by weight, 12-15 parts polyethylene glycol modified siloxane, 5-6 parts L-allyl glycine, 80-100 parts dimethyl sulfoxide, and 0.05-0.1 parts 4-dimethylaminopyridine. The modified halloysite nanotubes comprise the following components: by weight, 12-15 parts amino-alkenylated siloxane, 8-10 parts epoxidized halloysite nanotubes, and 80-100 parts tetrahydrofuran.

7. The method for preparing a button cell according to claim 5, characterized in that: The membrane comprises the following components by weight: 50-60 parts polypropylene resin, 5-8 parts modified halloysite nanotubes, 0.1-0.2 parts initiator, and 4-5 parts antioxidant; the thickness of the zeolite coating is 2-4 μm.

8. The method for preparing a button cell according to claim 7, characterized in that: The membrane comprises the following components: the initiator comprises one of benzoyl peroxide and lauroyl peroxide; the antioxidant comprises one or more of hindered phenolic antioxidants and thioester antioxidants.

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