A cross-linked polymer organic electrode material and a preparation method and application thereof

Abstract

The application belongs to the field of lithium ion battery electrode materials, and particularly relates to a cross-linked polymer organic electrode material and a preparation method and application thereof. The organic electrode material is obtained by cross-linking reaction of bis(3,4-oxyphenyl ether) ketone, dimethylol formaldehyde and anhydrous ferric chloride in 1,2-dichloroethane to obtain an intermediate cross-linked polymer, and then by demethylation and oxidation to obtain the cross-linked polymer organic electrode material. The lithium ion battery is constructed by using the cross-linked polymer material as the electrode material, and a specific capacity of up to 376 mAh / g and excellent cycle stability can be achieved under a current density of 0.1 C. The cross-linked polymer organic electrode material provided by the application solves the problems of low stability and low capacity of the existing organic electrode material, and has a good application prospect in the lithium ion battery system.

Description

Technical Field

[0001] This invention belongs to the field of organic electrode materials for lithium-ion batteries, specifically relating to a cross-linked polymer organic electrode material, its preparation method, and its application. Background Technology

[0002] Lithium-ion batteries are widely used in the market and are the mainstay of modern rechargeable batteries due to their advantages such as high specific energy, stable long cycle life, excellent rate performance, low self-discharge plateau, and low environmental pollution. However, current lithium-ion batteries are increasingly unable to meet the energy storage requirements of high capacity and fast charging, and there is an urgent need to develop lithium-ion batteries with high specific energy, long cycle life, and environmental friendliness.

[0003] Currently, quinone compounds have shown great potential as electrode materials for achieving high-power-density, high-energy-density, high-performance lithium-ion batteries and have been extensively studied. However, they face many challenges in practical applications. Firstly, small organic molecule quinone compounds are easily soluble in electrolytes, leading to poor cycle stability in lithium-ion batteries. Secondly, quinone compounds have poor conductivity, making it difficult to achieve high rate performance with quinone electrode materials. Thirdly, while the solubility problem of quinone compounds can generally be solved by constructing quinone polymers, this process introduces a large number of electrochemically inactive atoms or groups, reducing the specific capacity of these polymer electrode materials and making it difficult to achieve high specific capacity lithium-ion batteries.

[0004] Generally, cross-linked polymers tend to have low solubility in common solvents, which can help achieve stable cycle performance when used as electrode materials. Furthermore, their numerous microporous structures facilitate ion transport, enabling high rate capability to some extent. In addition, using the simplest carbon atom as the cross-linking element for benzoquinone structural units minimizes the introduction of non-electroactive atoms or groups, allowing for high specific capacity lithium-ion batteries. Summary of the Invention

[0005] In view of the shortcomings of the prior art, this invention provides a cross-linked polymer organic electrode material, its preparation method, and its application. This invention constructs a simple cross-linked polymer containing polyquinones, utilizing the cross-linked organic polymer to effectively suppress the dissolution of active materials in the electrolyte. Simultaneously, it achieves high specific capacity of quinone compounds and improves the cycle rate performance of quinone compound energy storage.

[0006] The present invention provides a cross-linked polymer organic electrode material with the following structural formula:

[0007]

[0008] The present invention also provides a method for preparing the above-mentioned cross-linked polymer organic electrode material, comprising the following steps:

[0009] (1) Under nitrogen or argon protection, bis(3,4-o-phenylenediol) ketone, dimethylformaldehyde and anhydrous ferric chloride are mixed evenly in 1,2-dichloroethane, heated to react, naturally cooled and purified to obtain a methoxy crosslinked polymer; wherein the molar ratio of bis(3,4-o-phenylenediol) ketone, dimethylformaldehyde and anhydrous ferric chloride is 1:3~6:3~6.

[0010] Further purification methods include: filtering the product after the reaction, washing with dichloromethane and DMF, then Soxhlet extraction with methanol (preferably at 70°C), and vacuum drying. Further, to improve the product yield, the reaction is heated at 45°C with stirring for 16–24 hours, then the temperature is increased to 80–90°C and the reaction continues for another 24 hours.

[0011] (2) The methoxy crosslinking polymer prepared in step (1) is heated and stirred in a mixed solution of hydrogen bromide and acetic acid, cooled naturally, filtered, washed with water and ethanol, and dried under vacuum to obtain a phenolic hydroxyl crosslinking polymer.

[0012] Furthermore, to improve the yield, the volume ratio of hydrogen bromide to acetic acid was 1:1; the heating reaction was carried out at 125°C with stirring for 24–32 hours.

[0013] (3) Under nitrogen or argon protection, the phenolic hydroxyl-containing crosslinked polymer obtained in step (3) is added to the oxidant solution, stirred and reacted, and then purified to obtain the crosslinked polymer electrode material. The oxidant in the oxidant solution is 2,3-dichloro-5,6-dicyanbenzoquinone (DDQ), the solvent is 1,4-dioxane, the mass concentration of the phenolic hydroxyl-containing crosslinked polymer in the solvent is 5% to 30%, and the mass ratio of the phenolic hydroxyl-containing crosslinked polymer to 2,3-dichloro-5,6-dicyanbenzoquinone is 1:5 to 10.

[0014] Further purification methods include filtration, washing with dichloromethane, DMF, and methanol, and vacuum drying. The vacuum drying temperature is generally 100°C.

[0015] The present invention also provides another method for preparing the above-mentioned cross-linked polymer organic electrode material, comprising the following steps:

[0016] 1) Under nitrogen or argon protection, bis(3,4-dimethyl ether) ketone, dichloromethane and boron tribromide are mixed evenly and stirred to react. Ice is added to the mixed solution to quench the reaction. The mixture is filtered and dried under vacuum to obtain pink solid bis(3,4-dimethyl ether) ketone.

[0017] Furthermore, to improve the yield, the molar ratio of bis(3,4-phthalic acid) ketone to boron tribromide is 1:8 to 10, and the mass concentration of bis(3,4-phthalic acid) ketone in the solvent is 5% to 30%.

[0018] 2) Under nitrogen or argon protection, the bis(3,4-catechol) ketone, dimethylformaldehyde and anhydrous ferric chloride prepared in step 1) are mixed evenly in 1,2-dichloroethane, heated to react, naturally cooled and purified; the molar ratio of bis(3,4-catechol) ketone, dimethylformaldehyde and anhydrous ferric chloride is 1:3~6:3~6.

[0019] Further purification methods include: filtering the product after the reaction, washing it with dichloromethane and DMF, extracting it with methanol using a Soxhlet extractor, and drying it under vacuum to obtain a phenolic hydroxyl crosslinked polymer.

[0020] Furthermore, in order to improve the yield, the heating reaction is carried out at 45°C with stirring for 16 to 24 hours, and then the temperature is raised to 80 to 90°C and the reaction is continued for 24 hours.

[0021] 3) Under nitrogen or argon protection, the phenolic hydroxyl-containing crosslinked polymer obtained in step 2) is added to an oxidant solution, heated and stirred to react, and then purified to obtain the crosslinked polymer electrode material. The oxidant in the oxidant solution is 2,3-dichloro-5,6-dicyanbenzoquinone, and the solvent is 1,4-dioxane. The mass concentration of the phenolic hydroxyl-containing crosslinked polymer in the solvent is 5%–30%, and the mass ratio of the phenolic hydroxyl-containing crosslinked polymer to 2,3-dichloro-5,6-dicyanbenzoquinone is 1:5–10. The mixture is filtered, washed with dichloromethane, DMF, and methanol, and then vacuum dried at a temperature generally around 100°C.

[0022] Furthermore, the preparation method of the above-mentioned bis(3,4-dimethyl ether) ketone includes the following steps: under nitrogen protection, dimethyl ether, 3,4-dimethoxybenzoic acid and polyphosphoric acid are mixed evenly, heated to react, naturally cooled, distilled water is added, the mixture is stirred to react, filtered to obtain a solid, the solid is dissolved in dichloromethane, washed with NaOH aqueous solution and distilled water, extracted, the organic layer is dried, and vacuum dried to obtain a white solid powder bis(3,4-dimethyl ether) ketone; wherein, the molar ratio of dimethyl ether to 3,4-dimethoxybenzoic acid is 1:1, and the heating reaction is carried out at 80-90°C with stirring for 4-6 hours.

[0023] Furthermore, the crosslinked polymer synthesis reaction route of the present invention is as follows:

[0024] Method 1:

[0025]

[0026] Or method 2:

[0027]

[0028] The present invention also provides a positive electrode for lithium-ion batteries based on a cross-linked polymer organic electrode material prepared by the above method, comprising the above-mentioned cross-linked polymer organic electrode material in a mass ratio of 6-8:1-3:1, conductive carbon material acetylene black, and binder polyvinylidene fluoride.

[0029] The above-mentioned method for preparing the positive electrode for lithium-ion batteries includes:

[0030] The obtained cross-linked polymer organic electrode material was mixed with conductive carbon material acetylene black and binder polyvinylidene fluoride in an organic solvent N-methyl-2-pyrrolidone (NMP) according to a set mass ratio to prepare a slurry. The slurry was then uniformly coated on a nickel grid and dried under vacuum at 80°C for 24 hours to obtain the positive electrode.

[0031] The advantages of this invention are as follows: The cross-linked polymer organic electrode material of this invention adopts a typical external cross-linking method, which is simple to synthesize, low in cost, and has a high yield. This cross-linked polymer organic material has multiple carbonyl electroactive sites, enabling multi-electron storage. The cross-linked polymer organic material has a cross-linked polymerization structure, which alleviates the solubility problem to some extent. The microporous structure of this cross-linked polymer facilitates the free shuttle of lithium ions, exhibiting high rate capability. Therefore, this cross-linked polymer organic electrode material can achieve high energy density, high rate capability, and high cycle stability. When applied to lithium-ion battery electrode materials, this cross-linked polymer organic material exhibits excellent performance and has broad application prospects. Attached Figure Description

[0032] Figure 1 The graphs show the cyclic voltammetry curves of the lithium-ion battery using M-1 as the electrode active material in Example 1, at a scan rate of 0.5 mV / s for one, two, and five cycles within a voltage range of 0.5–3 V.

[0033] Figure 2 The constant current charge-discharge curve of the lithium-ion battery with M-1 as the electrode active material in Example 1 at 0.1C is shown.

[0034] Figure 3 The graph shows the cyclic voltammetry curves of the lithium-ion battery using M-1 as the electrode active material in Example 3, within a voltage range of 0.5 to 3 V, at a scan rate of 0.5 mV / s.

[0035] Figure 4 The specific capacity and coulombic efficiency of the lithium-ion battery using M-1 as the electrode active material in Example 3 during long-term cycling at 0.1C are shown. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] Example 1

[0038] A method for preparing a cross-linked polymer organic lithium-ion electrode material includes the following steps:

[0039] 1. Synthesis of the cross-linked substrate bis(3,4-o-phenylene diether) ketone

[0040] Under a nitrogen atmosphere, 12 mmol (1.692 g) of phthalic acid, 12 mmol (2.208 g) of 3,4-dimethoxybenzoic acid, and 10 g of polyphosphoric acid were added to a 250 mL single-necked flask. The mixture was heated to 80 °C and stirred for 4 hours. Then, the temperature was lowered to 60 °C. The reaction was stopped when the reactants slowly turned orange-red. The mixture was cooled to room temperature, and 25 mL of distilled water was added to the reaction flask. The mixture was stirred until the solution slowly turned purple-red and the solid turned pale pink. The reaction was then stopped. The mixture was filtered, and the solid was dissolved in 15 mL of dichloromethane. The solution was washed with 3% NaOH aqueous solution and distilled water, extracted, and the organic layer was dried with anhydrous Na2SO4. Under vacuum, 1.8 g of bis(3,4-phthalic acid) methyl ketone (yield approximately 50%) was obtained as a white solid powder and dried at 50 °C. 1 H NMR (400MHz, CDCl3) δ7.47 (d, J = 1.9 Hz, 2H), 7.42 (d, J = 8.3, 1.9 Hz, 2H), 6.95 (d, J = 8.3 Hz, 2H), 4.01 (s, 6H), 3.98 (s, 6H).

[0041] 2. Synthesis of cross-linked polymers

[0042] In air, bis(3,4-o-phenylene diether) ketone (0.002 mol, 0.604 g), dimethyl formaldehyde (0.006 mol, 0.456 g), and anhydrous ferric chloride (0.006 mol, 0.975 g) were added to a 100 mL single-necked flask. 25 mL of 1,2-dichloroethane was added to the mixture, and the mixture was stirred at 45 °C for 18 hours to form a dense network. The temperature was then raised to 85 °C, and the reaction was continued for 24 hours. The reaction was then stopped, cooled to room temperature, filtered, and repeatedly washed with methanol to obtain a large amount of 0.6 g (yield approximately 95%) of a methyl-containing crosslinked polymer intermediate, which was dried at 100 °C.

[0043] 3. Demethylation of cross-linked polymers

[0044] 1 g of methyl-containing crosslinked polymer was mixed with 60 mL of a 1:1 mixture of hydrogen bromide and acetic acid. The mixture was stirred at 125 °C for 24 hours. The reaction was stopped, cooled to room temperature, and filtered to obtain 0.95 g of phenolic hydroxyl-containing crosslinked polymer (yield of about 96%). The polymer was washed repeatedly with methanol and dried at 100 °C.

[0045] 4. Oxidation of cross-linked polymers

[0046] Under nitrogen or argon protection, the phenolic hydroxyl crosslinking polymer and excess 2,3-dichloro-5,6-dicyanbenzoquinone (0.02 mol, 4.55 g) were mixed in 1,4-dioxane (15 mL) and stirred at room temperature for 48 hours. The reaction was then stopped, cooled to room temperature, filtered, and washed five times each with dichloromethane and DMF. The mixture was then extracted with methanol using a Soxhlet extract for 24 hours to obtain a large amount of the target product, 0.75 g (yield approximately 80%).

[0047] A lithium-ion battery, made of the aforementioned cross-linked polymer material, has the following electrochemical performance test results:

[0048] The obtained crosslinked polymer material, acetylene black, and binder polyvinylidene fluoride (PVDF) were mixed at a mass ratio of 6:3:1. 10 ml of N-methyl-2-pyrrolidone (NMP) was used as the solvent. The mixture was ground and then slurried using a high-speed emulsifier. This slurry was then uniformly coated onto the current collector, nickel foam. The mixture was then dried in a vacuum drying oven at 80°C for 24 hours to obtain the M-1 composite material. A lithium metal sheet was used as the negative electrode, the M-1 composite material as the positive electrode, Ce1grad 2550 as the separator, and the electrolyte was 1 mol / L lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The electrolyte solvent was a mixture of 1,3-dioxolane (DOL) and dimethyl ethylene glycol (DME) in a volume ratio of 1:1. The battery was assembled using conventional battery assembly processes.

[0049] The battery constructed according to this example exhibits two redox peak pairs in the cyclic voltammetry curve at a scan rate of 0.5 mV / s within the voltage range of 0.5–3 V, with potentials of 1.5 V and 2.52 V, indicating that the electrode material possesses excellent cycle stability (e.g., Figure 1 Furthermore, the peak operating voltage position matches the charge-discharge curve behavior. Charge-discharge data indicate that this electrode material exhibits a specific capacity as high as 812 mAh / g, and after 100 cycles, the specific capacity remains around 300 mAh / g (e.g., Figure 2 ).

[0050] Example 2

[0051] A method for preparing a lithium-ion battery electrode material is provided, following the synthesis route of Example 1.

[0052] A lithium-ion battery, made using the cross-linked polymer material as the electrode material, and its electrochemical performance was tested.

[0053] The material obtained in Example 1, acetylene black, and polyvinylidene fluoride (PVDF) binder were mixed at a mass ratio of 8:1:1. 10 ml of N-methyl-2-pyrrolidone (NMP) was used as the solvent. The mixture was ground and then slurried using a high-speed emulsifier. This slurry was then uniformly coated onto the current collector, nickel foam. The mixture was then dried in a vacuum drying oven at 80°C for 24 hours to obtain the M-2 composite material. A lithium metal sheet was used as the negative electrode, the M-2 composite material as the positive electrode, Ce1grad2550 as the separator, and the electrolyte was 1 mol / L lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The electrolyte solvent was a mixture of 1,3-dioxolane (DOL) and dimethyl ethylene glycol (DME) in a volume ratio of 1:1. The mixture was assembled into a battery using conventional battery assembly processes. The battery made according to this example and the test method shown in Example 1 had an initial discharge specific capacity of up to 800 mAh / g, and after 100 cycles, the specific capacity could be maintained at around 270 mAh / g.

[0054] Example 3

[0055] A method for preparing a lithium-ion battery electrode material includes the following steps:

[0056] 1. Synthesis of the cross-linked substrate bis(3,4-o-phenylene diether) ketone

[0057] Under a nitrogen atmosphere, 12 mmol (1.692 g) of phthalic acid, 12 mmol (2.208 g) of 3,4-dimethoxybenzoic acid, and 10 g of polyphosphoric acid were added to a 250 mL single-necked flask. The mixture was heated to 80 °C and stirred for 4 hours. Then, the temperature was lowered to 60 °C. The reaction was stopped when the reactants slowly turned orange-red. The mixture was cooled to room temperature, and 25 mL of distilled water was added to the reaction flask. The mixture was stirred overnight until the solution slowly turned purple-red and the solid turned pale pink. The reaction was then stopped. The solid was filtered and dissolved in 15 mL of dichloromethane. The solution was washed with 3% NaOH aqueous solution and distilled water, extracted, and the organic layer was dried with anhydrous Na2SO4. Under vacuum, 1.8 g (yield approximately 50%) of white solid powder bis(3,4-phthalic acid) ketone was obtained and dried at 50 °C.

[0058] 2. Synthesis of the cross-linking substrate bis(3,4-catechol) ketone

[0059] Under nitrogen ice bath conditions, bis(3,4-catechol) ketone (5 mmol, 1.51 g) was added to a 100 mL three-necked flask, a small amount of dichloromethane was added to the flask, and the mixture was stirred for 15 min. Then, 15 mL of BBr3 was slowly added dropwise to the solution, the temperature was raised to room temperature, and the reaction was stopped after stirring for 24 h. Ice was added to the mixed solution, and the reaction was quenched by stirring for 2 hours until the ice melted. The mixture was filtered to obtain a pink solid bis(3,4-catechol) ketone (0.85 g), which was then dried under vacuum at 40 °C. 1 H NMR (400MHz, DMSO) δ9.75 (s, 2H), 9.36 (s, 2H), 7.16 (s, 2H), 7.05 (d, J = 8.2Hz, 2H), 6.82 (d, J = 8.2Hz, 2H).

[0060] 3. Synthesis of cross-linked polymers

[0061] In air, bis(3,4-catechol) ketone (4 mmol, 1.0 g), dimethyl formaldehyde (12 mmol, 0.927 g), and anhydrous ferric chloride (12 mmol, 1.978 g) were added to a 100 mL single-necked flask. 25 mL of 1,2-dichloroethane was added to the mixture, and the mixture was heated to 45 °C and stirred for 18 hours to form a dense, yellow precipitate. The mixture was then heated to 85 °C and the reaction was continued for 24 hours. The reaction was stopped, cooled to room temperature, filtered, and washed repeatedly with methanol and water to obtain a large amount of methyl-containing crosslinked polymer intermediate M4 (1.1 g) (yield approximately 98%), which was then dried at 80 °C.

[0062] 4. Oxidation of cross-linked polymers

[0063] Under nitrogen or argon protection, the phenolic hydroxyl crosslinking polymer and excess 2,3-dichloro-5,6-dicyanbenzoquinone (0.02 mol, 4.55 g) were mixed in 1,4-dioxane (15 mL) and stirred at room temperature for 48 hours. The reaction was then stopped, cooled to room temperature, filtered, and washed five times each with dichloromethane and DMF. Finally, the mixture was extracted with methanol using a Soxhlet extract for 24 hours to obtain a large amount of the target product, 0.96 g (yield approximately 90%).

[0064] A lithium-ion battery, made using the aforementioned cross-linked polymer as the active material, has the following electrochemical performance test results:

[0065] The obtained cross-linked polymer electrode material was assembled into a button cell according to the process in Example 1, and its charge / discharge capacity and cycle characteristics were tested.

[0066] The battery constructed according to this example exhibits two pairs of reversible redox peaks in its cyclic voltammetry curves within the voltage range of 0.5–3 V at a scan rate of 0.5 mV / s, indicating that the electrode material possesses excellent cycle stability (e.g., Figure 3 The initial discharge specific capacity reaches 752 mAh / g, with an initial efficiency of 107.90%. After 100 cycles, the specific capacity remains around 376 mAh / g, further demonstrating the high specific capacity and excellent cycling stability of the electrode material. Figure 3 This explains the specific process of preparing cross-linked polymer materials, which to some extent affects the polymer's microstructure and also has some impact on its performance.

[0067] Example 4

[0068] A method for preparing a cross-linked polymer electrode material is described in Example 3, involving a four-step synthesis.

[0069] A lithium-ion battery, made using the cross-linked polymer material as the electrode material, and its electrochemical performance was tested.

[0070] The cross-linked polymer material obtained in Example 3, acetylene black, and polyvinylidene fluoride (PVDF) binder were mixed at a mass ratio of 8:1:1. 10 ml of N-methyl-2-pyrrolidone (NMP) was used as the solvent. The mixture was ground and then slurried using a high-speed emulsifier. This slurry was then uniformly coated onto the current collector foam nickel. The mixture was then dried in a vacuum drying oven at 80°C for 24 hours for later use. A lithium metal sheet was used as the negative electrode, M-2 composite material as the positive electrode, Ce1grad2550 as the separator, and 1 mol / L lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was used as the electrolyte. The electrolyte solvent was a mixture of 1,3-dioxolane (DOL) and ethylene glycol dimethyl ether (DME) in a volume ratio of 1:1. The mixture was assembled into a battery using conventional battery assembly processes.

[0071] The battery made according to this example has an initial discharge specific capacity of up to 709 mAh / g and an initial efficiency of 87%. After 100 cycles, the specific capacity can be maintained at around 202 mAh / g.

[0072] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. For those skilled in the art, several improvements and substitutions can be made based on the technical solutions of the present invention without creative effort, and all such improvements and substitutions fall within the protection scope of the present invention.

Claims

1. A cross-linked polymeric organic electrode material, characterized in that, The electrode material The electrode material is obtained by: (1) uniformly mixing bis(3,4-oxyphenylene ether) ketone, dimethyl glycol formaldehyde and anhydrous ferric chloride in 1,2-dichloroethane under nitrogen or argon protection, heating the reaction, naturally cooling, purifying, and obtaining a methoxy-containing cross-linked polymer; wherein the molar ratio of bis(3,4-oxyphenylene ether) ketone, dimethyl glycol formaldehyde and anhydrous ferric chloride is 1:3-6:3-6; (2) heating and stirring the methoxy-containing cross-linked polymer prepared in step (1) in a hydrogen bromide and acetic acid mixed solution to react, naturally cooling, filtering, washing with water and ethanol, and vacuum drying to obtain a phenolic hydroxyl-containing cross-linked polymer; (3) under nitrogen or argon protection, adding the phenolic hydroxyl-containing cross-linked polymer obtained in step (3) into an oxidizing agent solution, stirring to react, and then purifying to obtain a cross-linked polymer electrode material; the oxidizing agent in the oxidizing agent solution is 2,3-dichloro-5,6-dicyano-benzoquinone, the solvent is 1,4-dioxane, the mass concentration of the phenolic hydroxyl-containing cross-linked polymer in the solvent is 5%-30%, and the mass ratio of the phenolic hydroxyl-containing cross-linked polymer to 2,3-dichloro-5,6-dicyano-benzoquinone is 1:5-10; Alternatively, 1) uniformly mixing bis(3,4-oxyphenylene ether) ketone, dichloromethane and boron tribromide under nitrogen or argon protection, stirring to react, adding ice into the mixed solution to quench the reaction, filtering, and vacuum drying to obtain pink solid bis(3,4-oxyphenol) ketone; 2) uniformly mixing the bis(3,4-oxyphenol) ketone prepared in step 1), dimethyl glycol formaldehyde and anhydrous ferric chloride in 1,2-dichloroethane under nitrogen or argon protection, heating the reaction, naturally cooling, and purifying; the molar ratio of bis(3,4-oxyphenol) ketone, dimethyl glycol formaldehyde and anhydrous ferric chloride is 1:3-6:3-6; 3) under nitrogen or argon protection, adding the phenolic hydroxyl-containing cross-linked polymer obtained in step 2) into an oxidizing agent solution, heating and stirring to react, and then purifying to obtain a cross-linked polymer electrode material; the oxidizing agent in the oxidizing agent solution is 2,3-dichloro-5,6-dicyano-benzoquinone, the solvent is 1,4-dioxane, the mass concentration of the phenolic hydroxyl-containing cross-linked polymer in the solvent is 5%-30%, and the mass ratio of the phenolic hydroxyl-containing cross-linked polymer to 2,3-dichloro-5,6-dicyano-benzoquinone is 1:5-10.

2. A method for producing the cross-linked polymer organic electrode material as claimed in claim 1, characterized by, The method comprises the following steps: (1) uniformly mixing bis(3,4-oxyphenylene ether) ketone, dimethyl glycol formaldehyde and anhydrous ferric chloride in 1,2-dichloroethane under nitrogen or argon protection, heating the reaction, naturally cooling, purifying, and obtaining a methoxy-containing cross-linked polymer; wherein the molar ratio of bis(3,4-oxyphenylene ether) ketone, dimethyl glycol formaldehyde and anhydrous ferric chloride is 1:3-6:3-6; (2) heating and stirring the methoxy-containing cross-linked polymer prepared in step (1) in a hydrogen bromide and acetic acid mixed solution to react, naturally cooling, filtering, washing with water and ethanol, and vacuum drying to obtain a phenolic hydroxyl-containing cross-linked polymer; (3) under the protection of nitrogen or argon, the phenolic hydroxyl-containing cross-linked polymer obtained in step (3) is added into an oxidant solution, and then stirred and reacted, and then purified to obtain the cross-linked polymer electrode material; the oxidant in the oxidant solution is 2,3-dichloro-5,6-dicyano-benzoquinone, the solvent is 1,4-dioxane, the mass concentration of the phenolic hydroxyl-containing cross-linked polymer in the solvent is 5% to 30%, and the mass ratio of the phenolic hydroxyl-containing cross-linked polymer to 2,3-dichloro-5,6-dicyano-benzoquinone is 1:5 to 10.

3. The method of claim 2, wherein the cross-linking is performed by irradiation with ultraviolet rays, electron beams, or the like.

3. The method of claim 2, wherein the cross-linking is performed by irradiation with ultraviolet rays, electron beams, or the like. The purification method in step (1) comprises the following steps: filtering the product after the reaction is completed, then washing the product with dichloromethane and DMF, then performing Soxhlet extraction with methanol, and then vacuum drying; And / or, the heating reaction in step (1) is stirring reaction at 45°C for 16 to 24 hours, and then heating to 80 to 90°C and continuing to react for 24 hours; And / or, the volume ratio of hydrogen bromide to acetic acid in step (2) is 1:1; the heating reaction is stirring reaction at 125°C for 24 to 32 hours; And / or, the purification method in step (3) comprises the following steps: filtering, washing with dichloromethane, DMF and methanol, and vacuum drying.

4. A method of producing the cross-linked polymer organic electrode material as claimed in claim 1, characterized by, The method comprises the following steps: 1) under the protection of nitrogen or argon, bis(3,4-oxybenzyl) ketone, dichloromethane and boron tribromide are uniformly mixed, stirred and reacted, ice is added into the mixed solution to quench the reaction, the mixture is filtered under suction, and then vacuum dried to obtain pink solid bis(3,4-oxybenzyl) ketone; 2) under the protection of nitrogen or argon, the bis(3,4-oxybenzyl) ketone prepared in step 1), dimethyl glycol formal and anhydrous ferric chloride are uniformly mixed in 1,2-dichloroethane, heated and reacted, naturally cooled, and then purified; the molar ratio of bis(3,4-oxybenzyl) ketone, dimethyl glycol formal and anhydrous ferric chloride is 1:3 to 6:3 to 6; 3) under the protection of nitrogen or argon, the phenolic hydroxyl-containing cross-linked polymer obtained in step 2) is added into an oxidant solution, heated and stirred, and then purified to obtain the cross-linked polymer electrode material; the oxidant in the oxidant solution is 2,3-dichloro-5,6-dicyano-benzoquinone, the solvent is 1,4-dioxane, the mass concentration of the phenolic hydroxyl-containing cross-linked polymer in the solvent is 5% to 30%, and the mass ratio of the phenolic hydroxyl-containing cross-linked polymer to 2,3-dichloro-5,6-dicyano-benzoquinone is 1:5 to 10.

5. The method for preparing the cross-linked polymer organic electrode material according to claim 4, characterized in that, In step 1), the molar ratio of bis(3,4-oxybenzyl) ketone to boron tribromide is 1:8 to 10, and the mass concentration of bis(3,4-oxybenzyl) ketone in the solvent is 5% to 30%; And / or, the purification method in step (2) comprises the following steps: filtering the product after the reaction is completed, then washing the product with dichloromethane and DMF, then performing Soxhlet extraction with methanol, and then vacuum drying; And / or, the heating reaction in step (2) is stirring reaction at 45°C for 16 to 24 hours, and then heating to 80 to 90°C and continuing to react for 24 hours; And / or, the purification method in step (3) comprises the following steps: filtering, washing with dichloromethane, DMF and methanol, and vacuum drying.

6. The method of producing a cross-linked polymeric organic electrode material according to any one of claims 2 to 5, characterized in that, The preparation method of bis(3,4-oxydianiline) ketone comprises the following steps: uniformly mixing o-dianisyl ether, 3,4-dimethoxybenzoic acid and polyphosphoric acid under nitrogen protection, heating and reacting, naturally cooling, adding distilled water, stirring and reacting, extracting, drying the organic layer, vacuum drying, and obtaining white solid powder bis(3,4-oxydianiline) ketone; wherein the molar ratio of o-dianisyl ether and 3,4-dimethoxybenzoic acid is 1:1, and the heating and reacting is stirring and reacting at 80-90 DEG C for 4-6 hours.

7. A positive electrode for a lithium ion battery, characterized by comprising a positive electrode active material according to any one of claims 1 to 6. The electrode comprises the cross-linked polymer organic electrode material, the conductive carbon material and the binder in a mass ratio of 6-8:1-3:

1.

8. The method for producing a positive electrode for lithium-ion batteries according to claim 7, characterized by, The electrode comprises the cross-linked polymer organic electrode material, the conductive carbon material and the binder in a mass ratio of 6-8:1-3:

1.

9. The method for producing a positive electrode for a lithium-ion battery according to claim 8, characterized by, The vacuum drying condition is 80 DEG C vacuum drying for 24 hours.

Images