Polyazobenzene-naphthalene tetracarboxylic anhydride material, preparation method and application in secondary battery

Abstract

The invention discloses a polyazobenzene-naphthalene tetracarboxylic anhydride material, a preparation method and an application of the polyazobenzene-naphthalene tetracarboxylic anhydride material in a secondary battery, and belongs to the field of secondary batteries. The chemical structural formula of the polyazobenzene-naphthalene tetracarboxylic anhydride material is shown in the specification: # imgabs0 # polyazobenzene-naphthalene tetracarboxylic anhydride material has a long-range conjugated skeleton and abundant electroactive sites and electroactive centers, so that the ionic conductivity and capacity of the polyazobenzene-naphthalene tetracarboxylic anhydride material are improved. And the polyazobenzene-naphthalene tetracarboxylic anhydride material also shows a rigid framework, so that the charge-discharge volume expansion of the positive electrode material is inhibited, and the cycle life of the positive electrode material is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary batteries, in particular to a polyazobenzene-naphthalenetetracarboxylic anhydride material, a preparation method and an application in secondary batteries. Background Art

[0002] Lithium-ion batteries are currently widely used in portable devices, electric vehicles, and grid energy storage. However, as technology advances, lithium-ion batteries face the following challenges: First, increasing energy density has hit a bottleneck, limiting battery life; second, the reliance on transition metals such as cobalt and nickel in inorganic cathode materials has raised concerns about resource scarcity and sustainability. Organic cathode materials, due to their significant potential in electrochemical performance and significant advantages in resource sustainability, have gradually become a research hotspot.

[0003] However, current organic cathode materials typically have a dense structure, which reduces ionic conductivity and leads to poor electrochemical performance of lithium-ion batteries. Summary of the Invention

[0004] In view of this, the present invention provides a polyazobenzene-naphthalenetetracarboxylic anhydride material, a preparation method and application in a secondary battery, which can solve the technical problems existing in the related art.

[0005] Specifically, the following technical solutions are included:

[0006] In one aspect, a polyazobenzene-naphthalenetetracarboxylic anhydride material is provided, and the chemical structural formula of the polyazobenzene-naphthalenetetracarboxylic anhydride material is shown below:

[0007]

[0008] On the other hand, a method for preparing a polyazobenzene-naphthalenetetracarboxylic anhydride material is provided, wherein the polyazobenzene-naphthalenetetracarboxylic anhydride material is as described above;

[0009] The polyazobenzene-naphthalenetetracarboxylic anhydride material is prepared by a dehydration condensation reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene.

[0010] In some possible implementations, the preparation method includes:

[0011] Dissolve the 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene in a solvent and stir evenly under a protective atmosphere;

[0012] Under the action of a catalyst, the reaction system is reflux-heated to obtain a product system;

[0013] The polyazobenzene-naphthalenetetracarboxylic anhydride material is separated from the product system.

[0014] In some possible implementations, the usage of the 1,4,5,8-naphthalenetetracarboxylic dianhydride, the diaminoazobenzene, and the solvent is: 1.0 g to 1.5 g: 0.7 g to 1.2 g: 40 mL to 70 mL.

[0015] In some possible implementations, the catalyst is isoquinoline, and the amount of isoquinoline used is 1 mL to 5 mL.

[0016] In some possible implementations, the reflux heating temperature is 100°C to 130°C.

[0017] In some possible implementations, the separating and obtaining the polyazobenzene-naphthalenetetracarboxylic anhydride material from the product system comprises:

[0018] Separating a solid product from the product system;

[0019] The solid product was filtered and washed with ethanol, and then washed again with acetone and N-methylpyrrolidone in sequence;

[0020] The washed product is vacuum dried to obtain the polyazobenzene-naphthalenetetracarboxylic anhydride material, wherein the vacuum drying temperature is 100° C. to 150° C., and the vacuum drying time is 12 hours to 24 hours.

[0021] In another aspect, a positive electrode active material for a battery is provided, wherein the positive electrode active material for the battery comprises the polyazobenzene-naphthalenetetracarboxylic anhydride material.

[0022] On the other hand, a positive electrode plate is provided, which includes a current collector and a positive electrode active material layer coated on the surface of the current collector, and the positive electrode active material layer includes the above-mentioned battery positive electrode active material, as well as a conductive agent and a binder.

[0023] On the other hand, a lithium-ion battery is provided, characterized in that the lithium-ion battery includes a positive electrode sheet, a negative electrode sheet, a battery separator and an electrolyte, and the positive electrode sheet and the negative electrode sheet are separated by the battery separator; wherein the positive electrode sheet is as described above.

[0024] The beneficial effects of the technical solution provided by the embodiment of the present invention include at least:

[0025] The polyazobenzene-naphthalenetetracarboxylic anhydride material is prepared by a dehydration condensation reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene. Its skeleton is a linear conjugated chain formed by connecting a naphthalene ring (rigid aromatic ring), an azo group (-N=N-) and an imide bond (-CO-NH-CO-), so that the polyazobenzene-naphthalenetetracarboxylic anhydride has a long-range conjugated skeleton, which is conducive to the formation of electron transmission channels, improves ionic conductivity and reduces polarization.

[0026] The carbonyl group (C=O) on the naphthalene ring and the nitrogen atom (N=N) in the azo group are both active functional groups, serving as electroactive sites. Therefore, based on the polymerization of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene, the polyazobenzene-naphthalenetetracarboxylic anhydride material has abundant electroactive sites, which not only further promotes the ionic conductivity of the material, but also achieves the purpose of improving capacity by providing multi-electron storage sites.

[0027] The naphthalene rings are connected to the benzene rings in azobenzene via σ bonds, forming conjugated segments with alternating "naphthalene rings and azo groups." The π bonds of the naphthalene rings, the azo groups, and the benzene rings are continuously delocalized through the conjugation effect, forming electron transport channels throughout the molecular chain, which helps improve the ionic conductivity of the polyazobenzene-naphthalenetetracarboxylic anhydride material.

[0028] The naphthalene ring is a condensed aromatic structure (with a fixed bond angle and not easily distorted), and the N=N double bond in the azo group is a planar structure. The two are connected by an imide bond to form a "rigid rod-like" molecular chain, making the polyazobenzene-naphthalenetetracarboxylic anhydride material exhibit a rigid skeleton, which is beneficial for suppressing volume deformation during ion insertion / extraction (expansion rate <10%) and maintaining structural integrity.

[0029] In summary, the polyazobenzene-naphthalene tetracarboxylic anhydride material provided by the embodiment of the present invention has a long-range conjugated skeleton, as well as abundant electroactive sites and electroactive centers, which are beneficial to improving its ionic conductivity and capacity. The polyazobenzene-naphthalene tetracarboxylic anhydride material also exhibits a rigid skeleton, which is also beneficial to suppressing the charge and discharge volume expansion of the positive electrode material and improving its cycle life. It can be seen that the polyazobenzene-naphthalene tetracarboxylic anhydride achieves the synergistic optimization of conductivity, capacity and structural stability, making it show greater potential in terms of high-performance battery positive electrode materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1This is a cycling performance diagram of the lithium-ion button battery 2032 provided in Example 1 at a current density of 0.1 A / g;

[0032] Figure 2 This is a cycling performance diagram of the lithium-ion button battery 2032 provided in Example 1 at a current density of 2 A / g. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0034] To address the technical problem that current organic cathode materials generally have a dense structure, which reduces ionic conductivity and thus leads to poor electrochemical performance of lithium-ion batteries, the embodiments of the present invention provide a polyazobenzene-naphthalenetetracarboxylic anhydride material that can be used as a cathode material. The chemical structure of the polyazobenzene-naphthalenetetracarboxylic anhydride material is shown below:

[0035]

[0036] The polyazobenzene-naphthalenetetracarboxylic anhydride material is prepared by a dehydration condensation reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene. Its skeleton is a linear conjugated chain formed by connecting a naphthalene ring (rigid aromatic ring), an azo group (-N=N-) and an imide bond (-CO-NH-CO-), so that the polyazobenzene-naphthalenetetracarboxylic anhydride has a long-range conjugated skeleton, which is conducive to the formation of electron transmission channels, improves ionic conductivity and reduces polarization.

[0037] The carbonyl group (C=O) on the naphthalene ring and the nitrogen atom (N=N) in the azo group are both active functional groups, serving as electroactive sites. Therefore, based on the polymerization of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene, the polyazobenzene-naphthalenetetracarboxylic anhydride material has abundant electroactive sites, which not only further promotes the ionic conductivity of the material, but also achieves the purpose of improving capacity by providing multi-electron storage sites.

[0038] The naphthalene rings are connected to the benzene rings in azobenzene via σ bonds, forming conjugated segments with alternating "naphthalene rings and azo groups." The π bonds of the naphthalene rings, the azo groups, and the benzene rings are continuously delocalized through the conjugation effect, forming electron transport channels throughout the molecular chain, which helps improve the ionic conductivity of the polyazobenzene-naphthalenetetracarboxylic anhydride material.

[0039] The naphthalene ring is a condensed aromatic structure (with a fixed bond angle and not easily distorted), and the N=N double bond in the azo group is a planar structure. The two are connected by an imide bond to form a "rigid rod-like" molecular chain, making the polyazobenzene-naphthalenetetracarboxylic anhydride material exhibit a rigid skeleton, which is beneficial for suppressing volume deformation during ion insertion / extraction (expansion rate <10%) and maintaining structural integrity.

[0040] In summary, the polyazobenzene-naphthalene tetracarboxylic anhydride material provided by the embodiment of the present invention has a long-range conjugated skeleton, as well as abundant electroactive sites and electroactive centers, which are beneficial to improving its ionic conductivity and capacity. The polyazobenzene-naphthalene tetracarboxylic anhydride material also exhibits a rigid skeleton, which is also beneficial to suppressing the charge and discharge volume expansion of the positive electrode material and improving its cycle life. It can be seen that the polyazobenzene-naphthalene tetracarboxylic anhydride achieves the synergistic optimization of conductivity, capacity and structural stability, making it show greater potential in terms of high-performance battery positive electrode materials.

[0041] On the other hand, an embodiment of the present invention provides a method for preparing a polyazobenzene-naphthalenetetracarboxylic anhydride material. The polyazobenzene-naphthalenetetracarboxylic anhydride material is as described above.

[0042] The polyazobenzene-naphthalenetetracarboxylic anhydride material is prepared by carrying out a dehydration condensation reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene.

[0043] Through a dehydration condensation reaction, the small molecules of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene are dehydrated and condensed to form a long conjugated polymer, namely, the polyazobenzene-naphthalenetetracarboxylic anhydride material. This not only solves the solubility problem of small molecule organic matter in the electrolyte, but also effectively retains the original active functional groups of the small molecule organic matter and fully exposes them in the long conjugated polymer, which helps to improve the conductive properties of the polyazobenzene-naphthalenetetracarboxylic anhydride material. In addition, both 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene have rigid skeletons. When introduced into the polyazobenzene-naphthalenetetracarboxylic anhydride material, when used as a positive electrode material, it also helps to suppress the charge and discharge volume expansion of the polyazobenzene-naphthalenetetracarboxylic anhydride material, thereby improving its cycle life.

[0044]

[0045] In some examples, the preparation method of the polyazobenzene-naphthalenetetracarboxylic anhydride material includes the following preparation steps:

[0046] Step S1: dissolving 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene in a solvent, and stirring the mixture evenly under a protective atmosphere.

[0047] Step S2: reflux heating the reaction system under the action of a catalyst to obtain a product system.

[0048] Step S3: separating and obtaining the polyazobenzene-naphthalenetetracarboxylic anhydride material from the product system.

[0049] The purpose of step S1 is to uniformly dissolve 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene in a solvent, and stir them evenly under a protective atmosphere to effectively prevent problems such as oxidation of the raw materials. Subsequently, step S2 is performed to carry out a reflux polycondensation reaction under the action of a catalyst to obtain a product system containing polyazobenzene-naphthalenetetracarboxylic anhydride. Finally, step S3 is used to separate the product system to obtain a polyazobenzene-naphthalenetetracarboxylic anhydride material.

[0050] In some examples, the solvent involved may be a phenolic solvent, such as m-cresol (also known as 3-methylphenol), phenol, catechol, etc., which has a good dissolving effect on 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene.

[0051] In order to ensure the alternating copolymerization of polyazobenzene monomer and naphthalene tetracarboxylic anhydride monomer in the polyazobenzene-naphthalene tetracarboxylic anhydride material and avoid branching defects, and at the same time, the amount of solvent can ensure sufficient dissolution and high-temperature reaction uniformity, the amount of 1,4,5,8-naphthalene tetracarboxylic dianhydride, diaminoazobenzene and solvent (such as m-cresol) can be made as follows:

[0052] The mass of 1,4,5,8-naphthalenetetracarboxylic dianhydride is 1.0 g to 1.5 g, the mass of diaminoazobenzene is 0.7 g to 1.2 g, and the volume of the solvent is 40 mL to 70 mL.

[0053] The mass of 1,4,5,8-naphthalenetetracarboxylic dianhydride can further be 1.0 g, 1.1 g, 1.2 g, 1.3 g, 1.4 g, or 1.5 g.

[0054] The mass of diaminoazobenzene can further be 0.7 g, 0.8 g, 0.9 g, 1.0 g, 1.1 g, 1.2 g, etc.

[0055] The volume of the solvent can further be 40 mL, 45 mL, 50 mL, 55 mL, 60 mL, 65 mL, 70 mL, etc.

[0056] The amounts of 1,4,5,8-naphthalenetetracarboxylic dianhydride, diaminoazobenzene and solvent can be arbitrarily combined in the above scheme.

[0057] In some examples, the catalyst used is isoquinoline, and the amount of isoquinoline used is 1 mL to 5 mL, including but not limited to: 1 mL, 1.5 mL, 2 mL, 2.5 mL, 3 mL, 3.5 mL, 4 mL, 4.5 mL, 5 mL, etc.

[0058] As a catalyst, isoquinoline has the function of catalyzing dehydration and ring closure, which is beneficial to improving the polymerization reaction effect and polymerization degree.

[0059] In some examples, when 1,4,5,8-naphthalenetetracarboxylic dianhydride and para-diaminoazobenzene undergo a dehydration condensation reaction, the reflux heating temperature is 100°C to 130°C, including but not limited to 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, etc., to ensure that the dehydration condensation reaction is fully and thoroughly carried out.

[0060] In some examples, polyazobenzene-naphthalenetetracarboxylic anhydride materials are isolated from the product system, including:

[0061] A solid product is isolated from the product system. The solid product is filtered and rinsed with ethanol, and then washed again with acetone and N-methylpyrrolidone. The washed product is vacuum dried to obtain a polyazobenzene-naphthalenetetracarboxylic anhydride material, wherein the vacuum drying temperature is 100°C to 150°C and the vacuum drying time is 12 hours to 24 hours.

[0062] Through the above operation, the residual catalyst and solvent in the product system can be completely removed to obtain a high-purity polyazobenzene-naphthalenetetracarboxylic anhydride material, thereby avoiding degradation of its performance as a positive electrode material. In particular, the above-mentioned limitation on the process parameters of vacuum drying can not only ensure sufficient drying of the washed product, but also prevent thermal decomposition of the polyazobenzene-naphthalenetetracarboxylic anhydride material, thereby ensuring the stability of the polyazobenzene-naphthalenetetracarboxylic anhydride material.

[0063] On the other hand, an embodiment of the present invention provides a positive electrode active material for a battery, wherein the positive electrode active material for the battery includes the polyazobenzene-naphthalenetetracarboxylic anhydride material mentioned above.

[0064] The polyazobenzene-naphthalenetetracarboxylic anhydride material, as a positive electrode active material of a battery, can provide the battery positive electrode active material with all the advantages mentioned above, which will not be described in detail here.

[0065] In some examples, the battery positive electrode active material includes 100% by weight of the polyazobenzene-naphthalenetetracarboxylic anhydride material.

[0066] In other examples, the battery's positive electrode active material may include, in addition to the polyazobenzene-naphthalene tetracarboxylic anhydride material, other positive electrode active materials or additives. Other positive electrode active materials, for example, may be currently known positive electrode active materials, and additives, such as lithium salts, may be used to promote ion conduction. The selection can be based on actual needs. For this solution, it is desirable that the mass percentage of the polyazobenzene-naphthalene tetracarboxylic anhydride material be greater than or equal to 80%.

[0067] On the other hand, an embodiment of the present invention provides a positive electrode plate, which includes a current collector and a positive electrode active material layer coated on the surface of the current collector, and the positive electrode active material layer includes the above-mentioned battery positive electrode active material, as well as a conductive agent and a binder.

[0068] The positive electrode plate provided by the embodiment of the present invention has all the advantages of the polyazobenzene-naphthalenetetracarboxylic anhydride material mentioned above, which will not be described in detail here.

[0069] The current collector is used to carry active materials and conduct current. In some examples, the current collector can be aluminum foil, titanium foil, stainless steel foil, etc.

[0070] Conductive agents are used to build an electron transport network, filling the gaps between the cathode active material particles to form a continuous conductive path, thereby improving the overall electron conductivity of the cathode. In some examples, the conductive agent can be acetylene black, carbon nanotubes, graphene, Ketjen black, silver powder, etc.

[0071] The binder physically or chemically bonds the positive electrode active material and the conductive agent to the current collector to prevent them from falling off during cycling. For example, the binder can be an organic binder, such as a polyimide binder, a polyacrylic binder, or a polyvinylidene fluoride binder.

[0072] For any of the above-mentioned positive electrode sheets, in some examples, the mass ratio of the positive electrode active material, the conductive agent, and the binder can be 5-9:1-5:1-3.

[0073] In another aspect, embodiments of the present invention provide a lithium-ion battery comprising a positive electrode sheet, a negative electrode sheet, a battery separator, and an electrolyte, wherein the positive electrode sheet and the negative electrode sheet are separated by the battery separator; wherein the positive electrode sheet is as described above. This lithium-ion battery has all the advantages of the polyazobenzene-naphthalenetetracarboxylic anhydride material described above, and will not be further elaborated here.

[0074] Below will be described in more detail exemplary embodiments of the present invention. Although the following describes exemplary embodiments of the present invention, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. In the examples, if specific techniques or conditions are not indicated, they are carried out according to the techniques or conditions described in the literature in this area or according to the product specifications. Reagents or instruments used that do not indicate the manufacturer are conventional products that can be obtained commercially.

[0075] Example 1

[0076] This embodiment 1 provides a polyazobenzene-naphthalenetetracarboxylic anhydride material, which is prepared by the following method:

[0077] Step 1: Add 1.34 g of 1,4,5,8-naphthalenetetracarboxylic dianhydride and 0.94 g of p-diaminoazobenzene to 50 mL of m-cresol and stir evenly at room temperature under a nitrogen atmosphere.

[0078] Step 2: Add 3 mL of isoquinoline to the solution in step 1, and heat the solution to 120° C. and reflux for 24 h.

[0079] Step 3: Separate the solid product from the product system, filter and rinse the solid product with ethanol, and continue washing with acetone and NMP. Subsequently, vacuum dry the washed product at 120° C. for 12 hours to prepare a polyazobenzene-naphthalenetetracarboxylic anhydride material.

[0080] The polyazobenzene-naphthalenetetracarboxylic anhydride material provided in Example 1 was used as the positive electrode active material to prepare the positive electrode sheet. Specifically, the polyazobenzene-naphthalenetetracarboxylic anhydride material, Ketjen black, and a binder (PVDF) were mixed in a mass ratio of 6:2:2, and N-methylpyrrolidone (NMP) solvent was evenly mixed and applied to the surface of the copper foil. The mixture was vacuum dried at 120°C for 24 hours to remove the NMP solvent to prepare a working electrode for a lithium-ion battery.

[0081] The corresponding mass loading of active substances is about 1.5 mg*cm -2 . Using glass fiber GF / D as the separator, metal lithium foil as the counter electrode, and 1 mol / L LiPO4 solution as the electrolyte. According to the order of negative electrode, counter electrode, separator, electrolyte, working electrode, gasket, and spring sheet, the lithium-ion button battery 2032 was assembled in a glove box filled with argon atmosphere, and then the electrochemical performance of the lithium-ion battery was tested on the NEWARE battery test system. (The test voltage was 1.1V-3.4V vs. Li + / Li).

[0082] Figure 1 The cycle performance of the lithium-ion button cell 2032 at a current density of 0.1 A / g is given by Figure 1 It can be seen that under low current density, the cycle specific capacity of the battery remains at 140mAh / g after 100 charge and discharge cycles.

[0083] Figure 2 The cycle performance of the lithium-ion button cell 2032 at a current density of 2 A / g is given by Figure 2 It can be seen that under high current density, the capacity retention rate of the battery is still as high as 70% even after 1000 charge and discharge cycles.

[0084] It can be seen that the polyazobenzene-naphthalenetetracarboxylic anhydride material is used as a positive electrode active material in lithium-ion batteries, making it exhibit excellent capacity and cycle performance.

[0085] The above description is only for the purpose of facilitating those skilled in the art to understand the technical solution of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A polyazobenzene-naphthalenetetracarboxylic anhydride material, characterized in that: The chemical structural formula of the polyazobenzene-naphthalenetetracarboxylic anhydride material is as follows:

2. A method for preparing a polyazobenzene-naphthalenetetracarboxylic anhydride material, characterized in that: The polyazobenzene-naphthalenetetracarboxylic anhydride material as claimed in claim 1; The polyazobenzene-naphthalenetetracarboxylic anhydride material is prepared by a dehydration condensation reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene.

3. The preparation method of polyazobenzene-naphthalenetetracarboxylic anhydride material according to claim 2, wherein The preparation method comprises: Dissolve the 1,4,5,8-naphthalenetetracarboxylic dianhydride and p-diaminoazobenzene in a solvent and stir evenly under a protective atmosphere; Under the action of a catalyst, the reaction system is reflux-heated to obtain a product system; The polyazobenzene-naphthalenetetracarboxylic anhydride material is separated from the product system.

4. The method for preparing the polyazobenzene-naphthalenetetracarboxylic anhydride material according to claim 3, wherein The usage of the 1,4,5,8-naphthalenetetracarboxylic dianhydride, the diaminoazobenzene and the solvent is: 1.0 g to 1.5 g: 0.7 g to 1.2 g: 40 mL to 70 mL.

5. The preparation method of polyazobenzene-naphthalenetetracarboxylic anhydride material according to claim 3, wherein The catalyst is isoquinoline, and the amount of the isoquinoline used is 1 mL to 5 mL.

6. The preparation method of the polyazobenzene-naphthalenetetracarboxylic anhydride material according to claim 3, wherein The reflux heating temperature is 100°C to 130°C.

7. The method for preparing the polyazobenzene-naphthalenetetracarboxylic anhydride material according to any one of claims 3 to 6, wherein: The method of separating the polyazobenzene-naphthalenetetracarboxylic anhydride material from the product system comprises: Separating a solid product from the product system; The solid product was filtered and washed with ethanol, and then washed again with acetone and N-methylpyrrolidone in sequence; The washed product is vacuum dried to obtain the polyazobenzene-naphthalenetetracarboxylic anhydride material, wherein the vacuum drying temperature is 100° C. to 150° C., and the vacuum drying time is 12 hours to 24 hours.

8. A positive electrode active material for a battery, characterized in that: The battery positive electrode active material comprises the polyazobenzene-naphthalenetetracarboxylic anhydride material according to claim 1.

9. A positive electrode plate, characterized in that: The positive electrode sheet includes a current collector and a positive electrode active material layer coated on a surface of the current collector, wherein the positive electrode active material layer includes the battery positive electrode active material according to claim 8, a conductive agent, and a binder.

10. A lithium ion battery, characterized in that: The lithium-ion battery comprises a positive electrode sheet, a negative electrode sheet, a battery separator and an electrolyte, wherein the positive electrode sheet and the negative electrode sheet are separated by the battery separator; Wherein, the positive electrode plate is as described in claim 9.

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