Phenanthrene quinone derivative for positive electrode material and preparation method and application thereof

Abstract

The invention relates to a phenanthrenequinone derivative for a positive electrode material as well as a preparation method and application of the phenanthrenequinone derivative. The phenanthrenequinonyl derivative is 1, 3, 5-tri (9, 10-phenanthrenequinonyl) benzene, the structural formula of the phenanthrenequinonyl derivative is as follows, the molecular formula of the phenanthrenequinonyl derivative is C48H24O6, and the relative molecular mass of the phenanthrenequinonyl derivative is 696.1573. A target product is obtained through ketalation reaction of carbonyl, coupling reaction and ketal removal reaction. A positive electrode material for a rechargeable secondary battery. The composite material has excellent electrochemical performance, for example, in LIBs, the capacity retention rate of TPQB after 1000 times of circulation is 76.8%, in AZIBs, the capacity retention rate of 6000 times of circulation is as high as 93.2%, and the average capacity attenuation of each circle is only about 0.001%. The cycle performance is the optimal level of the phenanthrenequinone derivative micromolecular organic positive electrode material which is publically reported at present, the unique advantage of the organic electrode material in universal storage of multivalent metal ions is disclosed, and the phenanthrenequinone electrode material has a wide application prospect. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the technical field of secondary batteries, and particularly to a phenanthraquinone derivative for a cathode material, a preparation method thereof, and applications in lithium-ion batteries and aqueous zinc-ion batteries. Background Art

[0002] Currently, commercially available secondary battery systems generally use inorganic intercalation-type cathode materials (such as lithium cobaltate, ternary materials, etc.), which have certain resource shortages and cost problems, and the rigid crystal structure restricts their adaptability to multivalent metal ions. Organic cathode materials based on the molecular redox mechanism provide a new idea for solving the above problems. Organic cathode materials represented by quinone derivatives are mainly composed of light elements such as C, H, O, N, etc., have rich natural resources, low cost efficiency, adjustable molecular structures, and flexible molecular skeletons that can adapt to multiple carriers (Li + , Na + , Zn 2+ , Mg 2+ , etc.) for reversible insertion / extraction. It is worth noting that anthraquinone compounds have made important progress in specific capacity and cycle stability through the expansion of the conjugated system and the directional modification of functional groups. It has been found that o-quinone compounds, especially phenanthraquinone (PQ), as isomers of anthraquinone, the synergistic electron-withdrawing effect of their adjacent carbonyl groups can increase the redox potential by about 0.3 V, thus achieving a higher energy density. However, the high solubility of phenanthraquinone and its discharge products in conventional liquid electrolytes leads to serious loss of active substances, resulting in rapid capacity decay and restricting its practical application. In the prior art, the cycle stability has been effectively improved by compounding phenanthraquinone with activated carbon, but due to the introduction of a large amount of activated carbon as a carrier, the specific capacity of the composite electrode has been greatly reduced; secondly, although the synthesis of phenanthraquinone-based polymers can inhibit dissolution, the utilization rate of active sites is often low, resulting in poor actual capacity expression and difficult to meet the technical requirements of high-energy density energy storage devices. Therefore, it is crucial to explore new phenanthraquinone-based organic electrode materials with low solubility and high cycle stability.

[0003] The core innovation of the present invention lies in the design and synthesis of a small molecule of phenanthraquinone-based derivative with low steric hindrance, 1,3,5-tris(9,10-phenanthraquinonyl)benzene (TPQB), which is used as a cathode material and applied to both lithium-ion batteries (LIBs) and aqueous zinc-ion batteries (AZIBs). Due to the low solubility of the TPQB molecule, the cycling stability of the organic battery is significantly improved. Among them, the capacity retention rate after 1000 cycles in LIBs is 76.8%, and the capacity retention rate after 6000 cycles in AZIBs is as high as 93.2%. This performance is the best among the reported small molecule organic cathode materials of phenanthraquinone derivatives. The present invention not only verifies the effectiveness of the molecular engineering strategy, but also reveals the unique advantage of organic electrode materials in universally storing multivalent metal ions, showing broad application prospects for phenanthraquinone-based electrode materials. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, this patent designs and synthesizes for the first time a phenanthraquinone-based derivative with low steric hindrance, 1,3,5-tris(9,10-phenanthraquinonyl)benzene (TPQB), which is used as a cathode material and applied to both lithium-ion batteries (LIBs) and aqueous zinc-ion batteries (AZIBs), obtaining excellent cycling stability. The present invention not only verifies the effectiveness of the molecular engineering strategy, but also reveals the unique advantage of organic electrode materials in universally storing multivalent metal ions, showing broad application prospects for phenanthraquinone-based electrode materials.

[0005] The present invention aims to solve the problems of high solubility of phenanthraquinone-based organic small molecule electrode materials in liquid electrolytes, as well as low utilization rate of active sites, low actual specific capacity, and poor cycling stability existing in the current prior art.

[0006] Through a simple organic synthesis method, the present invention synthesizes a phenanthraquinone-based organic small molecule, 1,3,5-tris(9,10-phenanthraquinonyl)benzene, which is used as an active substance and applied to the cathode material of rechargeable metal ion batteries (LIBs and AZIBs).

[0007] The technical solution of the present invention is as follows:

[0008] A phenanthraquinone-based derivative for cathode material, the phenanthraquinone-based derivative is 1,3,5-tris(9,10-phenanthraquinonyl)benzene (TPQB), and the structural formula is:

[0009]

[0010] Its molecular formula is C 48 H 24 O6, and the relative molecular mass is 696.1573.

[0011] In the mass spectrometry spectrum of the phenanthraquinone-based derivative TPQB, the characteristic ion [TPQB + H]+ The peak value corresponding to the peak should be 697.1573.

[0012] The infrared spectrum of the phenanthraquinone-based derivative TPQB should have a strong carbonyl absorption vibration peak with a wave number in the range of 1700 - 1600 cm -1 between.

[0013] The preparation method of the phenanthraquinone-based derivative of the present invention, the preparation of 1,3,5-tris(9,10-phenanthraquinonyl)benzene includes the following steps:

[0014] (1) Ketalization reaction of the carbonyl group: Under the protection of an inert atmosphere, add the raw materials 3-bromo-9,10-phenanthraquinone and ethylene glycol into the reaction flask. Under the catalysis of camphorsulfonic acid, add the reaction solvent, seal the reaction system and react at 139 - 141 °C for 11 - 13 hours; after the solution is naturally cooled to room temperature, pour it into water, let it stand and filter the precipitate, wash it with water, collect the crude product and dry it in an oven, and finally purify it by column chromatography to obtain a pure product;

[0015] (2) Coupling reaction: Using the common reaction system of the Suzuki coupling reaction, under the protection of an inert atmosphere, use tetrakis(triphenylphosphine)palladium as the catalyst, and add potassium carbonate. Couple the product of step (1) with 1,3,5-benzenetriboronic acid tris(pinacol) ester. Use toluene and methanol as the reaction solvents and react at 95 - 101 °C for 11 - 13 hours. Then filter the precipitate, wash it successively with toluene, water and ethanol, and purify it by Soxhlet extraction after drying to obtain the product;

[0016] (3) Ketal deprotection reaction: Put the product of step (2) into the reaction flask, add a mixed solution of trifluoroacetic acid / water, and react at 95 - 102 °C for 2 - 3 days. Then filter the precipitate, wash it with deionized water, and dry it to obtain the target product 1,3,5-tris(9,10-phenanthraquinonyl)benzene.

[0017] In the step (1) described above, the amount of the catalyst camphorsulfonic acid used is 0.3 equivalent of the raw material 3-bromo-9,10-phenanthraquinone.

[0018] In the step (1) described above, ethylene glycol should be in excess, and preferably the amount used should be greater than 130 times the molar amount of the raw material 3-bromo-9,10-phenanthraquinone.

[0019] In the step (1) described above, the reaction solvent is methanol or dioxane, and the preferred solvent is dioxane.

[0020] In the step (1) described above, the volume ratio of the reaction solvent to ethylene glycol is 2:1.

[0021] In the column chromatography method used in the step (1) described above, the volume ratio of ethyl acetate:petroleum ether of the eluent = 1:10 - 20, and the preferred volume ratio of the eluent is 1:20.

[0022] In step (2), the feed amount of 1,3,5-benzenetriboronic acid tris(pinacol) ester is 1 equivalent, the feed amount of the product in the first step is 4 equivalents, the feed amount of potassium carbonate is 3 equivalents, and the feed amount of tetrakis(triphenylphosphine)palladium is 0.1 equivalent.

[0023] In step (2), the volume ratio of the reaction reagents toluene and methanol is 40:5 to 3, and the preferred ratio is 40:4.

[0024] In step (2), the preferred reaction temperature is 100 °C.

[0025] In step (3), the volume ratio of trifluoroacetic acid to water is 8 to 10:1, and the preferred ratio is 9:1.

[0026] In step (3), the preferred reaction temperature is 100 °C.

[0027] The inert atmosphere is nitrogen or argon.

[0028] The phenanthraquinone derivatives of the present invention are used as the positive electrode material for rechargeable secondary batteries. Preferably, they are used in lithium ion batteries or aqueous zinc ion batteries.

[0029] The prepared TPQB, conductive agent, and binder are dispersed in N-methylpyrrolidone according to a mass ratio of 6:3:1, stirred well to obtain a positive electrode slurry, and then coated on a current collector. After drying at 60 °C for 6 hours, it is cut into electrode sheets and used as the positive electrode. The battery uses a 2032 type button battery;

[0030] In the lithium ion battery, the conductive agent is graphene, the current collector is carbon-coated aluminum foil, the negative electrode is a lithium metal foil, the separator is a Nafion-coated polypropylene separator, and the electrolyte uses 2M LiTFSI and 0.6M PEO in DOL / DME (V:V = 1:1), and the battery is assembled under an argon atmosphere.

[0031] In the aqueous zinc ion battery, the conductive agent is Ketjenblack, the current collector is titanium foil, the negative electrode is a zinc metal foil, the separator is a glass fiber, and the electrolyte uses a 3M Zn(OTf)2 aqueous solution.

[0032] After assembling the battery, it is placed in a Neware battery test system for electrochemical performance testing. The test voltage range is 1.5 - 3.5V (vs. Li / Li + ) / 0.25 - 1.6V (vs. Zn / Zn 2+ ).

[0033] The effects of the present invention are described as follows:

[0034] Features and advantages of the present invention: In the prior art, phenanthraquinone-based organic cathode materials applied to organic rechargeable secondary batteries have problems such as relatively low actual specific capacity and poor cycle stability; the present invention designs and synthesizes a novel phenanthraquinone-based organic compound TPQB, which has the advantage of low solubility while ensuring the specific capacity (231 mAh / g), and is applied to the cathode materials of lithium-ion batteries and aqueous zinc-ion batteries, with excellent electrochemical performance. For example, in LIBs, the capacity retention rate of TPQB is 76.8% after 1000 cycles, and in AZIBs, the capacity retention rate after 6000 cycles is as high as 93.2%, and the average capacity decay per cycle is only about 0.001%. This cycle performance is the best level of the reported phenanthraquinone derivative small molecule organic cathode materials at present, revealing the unique advantage of the universal storage of multivalent metal ions by organic electrode materials, and showing a broad application prospect of phenanthraquinone-based electrode materials. Brief Description of the Drawings

[0035] Figure 1 1H NMR spectra of BPQ-EGK (a) and TPQB-EGK in Example 4 (b); IR spectrum of TPQB (c); mass spectrum of TPQB (d).

[0036] Figure 2 Galvanostatic charge-discharge curves of the TPQB cathode material in a lithium-ion battery at 0.2C in Example 6.

[0037] Figure 3 Rate performance of the TPQB cathode material in a lithium-ion battery in Example 6.

[0038] Figure 4 Long cycle performance of the TPQB cathode material in a lithium-ion battery at 5C in Example 6.

[0039] Figure 5 Galvanostatic charge-discharge curves of the TPQB cathode material in an aqueous zinc-ion battery at 0.1C in Example 7.

[0040] Figure 6 Rate performance of the TPQB cathode material in an aqueous zinc-ion battery in Example 7.

[0041] Figure 7 Long cycle performance of the TPQB cathode material in an aqueous zinc-ion battery at 5C in Example 7. Detailed Description of the Invention

[0042] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further elaborates the present invention with specific embodiments.

[0043] Example 1 - Preparation Method of Phenanthraquinone-based Derivative 1,3,5-Tris(9,10-phenanthraquinonyl)benzene

[0044] (1) Ketalization reaction of the carbonyl group: Under the protection of an inert atmosphere, 4.43 mmol of 3-bromo-9,10-phenanthrenequinone and 1.33 mmol of camphorsulfonic acid (the amount of camphorsulfonic acid is 0.3 equivalent to 3-bromo-9,10-phenanthrenequinone) were put into a Schlenk pressure bottle. 35 mL of ethylene glycol was injected (the volume of ethylene glycol should be greater than 32 mL, and the calculation formula is as follows: V = m / ρ = 130*(4.43 / 1000)*62 / 1.113 = 32 mL, where the molar amount of the raw material 3-bromo-9,10-phenanthrenequinone is 4.43 mmol, m is the added mass of ethylene glycol, and ρ is the density of ethylene glycol). The reaction solvent used is ultra-dry methanol, and the amount used is 70 mL (the volume ratio of the reaction solvent methanol to ethylene glycol is 2:1). The reaction system was sealed and stirred continuously at 140 °C for 12 hours. After the system was naturally cooled to room temperature, it was poured into water, allowed to stand and the precipitate was filtered, washed with water, and 0.255 g of a yellowish-brown crude product was collected. After drying, the precipitate was purified by column chromatography, and the eluent was ethyl acetate:petroleum ether volume ratio = 1:20, and 0.065 g of a white solid was obtained, with a yield of 3.9%;

[0045]

[0046] (2) Coupling reaction: Under the protection of an inert atmosphere, 1.87 mmol of the product of step (1), 0.46 mmol of 1,3,5-benzenetriboronic acid tris(pinacol) ester, 1.4 mmol of potassium carbonate, and 0.04 mmol of tetrakis(triphenylphosphine)palladium (the feed of 1,3,5-benzenetriboronic acid tris(pinacol) ester is 1 equivalent, the feed of the product of step (1) is 4 equivalents, the feed of potassium carbonate is 3 equivalents, and tetrakis(triphenylphosphine)palladium is 0.1 equivalent) were added to a dry two-necked flask. Subsequently, 40 mL of ultra-dry toluene and 5 mL of ultra-dry methanol were injected. The reaction system was heated to 100 °C and stirred thoroughly for 12 hours. It was filtered while hot and washed successively with toluene, water, and ethanol. After drying, a white solid of 0.308 g was obtained after Soxhlet extraction, with a yield of 68.5%;

[0047] (3) Deprotection of ketal reaction: 0.35 mmol of the product of step (2) was added to a 100 mL flask, and then 50 mL of a mixed solution of trifluoroacetic acid / water = 10:1 was added. The reaction temperature was 100 °C, and it was stirred for 2 days. After cooling to room temperature, it was poured into 1000 mL of ice water, filtered, dried, and the precipitate was collected to obtain 0.196 g of yellow solid 1,3,5-tris(9,10-phenanthrenequinonyl)benzene, with a yield of 80.7%.

[0048] Example 2 - Preparation method of 1,3,5-tris(9,10-phenanthrenequinonyl)benzene, a phenanthrenequinone derivative

[0049] (1) Ketalization reaction of carbonyl group: Under the protection of an inert atmosphere, 4.43 mmol of 3-bromo-9,10-phenanthrenequinone and 1.33 mmol of camphorsulfonic acid (the dosage of camphorsulfonic acid is 0.3 equivalent of 3-bromo-9,10-phenanthrenequinone) were added into a Schlenk pressure bottle, and 35 mL of ethylene glycol was injected. The reaction solvent used was ultradry dioxane, and the dosage was 70 mL (the volume ratio of the reaction solvent dioxane to ethylene glycol was 2:1). The reaction system was sealed and stirred continuously at 140 °C for 12 hours. After the system was naturally cooled to room temperature, it was poured into water, allowed to stand, and the precipitate was filtered, washed with water, and 1.41 g of a yellowish-brown crude product was collected. After drying, the precipitate was purified by column chromatography, and the eluent was ethyl acetate:petroleum ether = 1:10 by volume, obtaining 0.46 g of a white solid with a yield of 27.8%;

[0050] (2) Coupling reaction: Under the protection of an inert atmosphere, 1.87 mmol of the product from step (1), 0.46 mmol of 1,3,5-benzenetriboronic acid tris(pinacol) ester, 1.4 mmol of potassium carbonate, and 0.04 mmol of tetrakis(triphenylphosphine)palladium (the feeding amount of 1,3,5-benzenetriboronic acid tris(pinacol) ester was 1 equivalent, the feeding amount of the product from step (1) was 4 equivalents, the feeding amount of potassium carbonate was 3 equivalents, and tetrakis(triphenylphosphine)palladium was 0.1 equivalent) were added into a dry two-necked flask. Subsequently, 40 mL of ultradry toluene and 3 mL of ultradry methanol were injected. The reaction system was heated to 100 °C and stirred thoroughly for 12 hours. It was filtered while hot and washed successively with toluene, water, and ethanol. After drying and Soxhlet extraction, 0.326 g of a white solid was obtained with a yield of 72.6%;

[0051] (3) De-ketalization reaction: 0.35 mmol of the product from step (2) was added into a 100 mL flask, and then 50 mL of a mixed solution of trifluoroacetic acid / water = 8:1 was added. The reaction temperature was 100 °C, and it was stirred for 2 days. After cooling to room temperature, it was poured into 1000 mL of ice water, filtered, dried, and the precipitate was collected to obtain 0.200 g of yellow solid 1,3,5-tris(9,10-phenanthrenequinonyl)benzene with a yield of 82.1%.

[0052] Preparation method of 3-phenanthrenequinone derivative 1,3,5-tris(9,10-phenanthrenequinonyl)benzene of Example 3

[0053] (1) Ketalization reaction of carbonyl group: Under the protection of an inert atmosphere, 4.43 mmol of 3-bromo-9,10-phenanthrenequinone and 1.33 mmol of camphorsulfonic acid (the amount of camphorsulfonic acid is 0.3 equivalent to 3-bromo-9,10-phenanthrenequinone) were added into a Schlenk pressure bottle, and 35 mL of ethylene glycol was injected. The reaction solvent used was ultradry dioxane, with a dosage of 70 mL (the volume ratio of the reaction solvent dioxane to ethylene glycol was 2:1). The reaction system was sealed and continuously stirred at 140 °C for 12 hours. After the system was naturally cooled to room temperature, it was poured into water, allowed to stand and the precipitate was filtered, washed with water, and 1.41 g of a yellowish-brown crude product was collected. After drying, the precipitate was purified by column chromatography, and the eluent was ethyl acetate:petroleum ether (volume ratio = 1:15), obtaining 0.715 g of a white solid with a yield of 43.2%;

[0054] (2) Coupling reaction: Under the protection of an inert atmosphere, 1.87 mmol of the product from step (1), 0.46 mmol of 1,3,5-benzenetriboronic acid tris(pinacol) ester, 1.4 mmol of potassium carbonate, and 0.04 mmol of tetrakis(triphenylphosphine)palladium (the feed of 1,3,5-benzenetriboronic acid tris(pinacol) ester was 1 equivalent, the feed of the product from step (1) was 4 equivalents, the feed of potassium carbonate was 3 equivalents, and tetrakis(triphenylphosphine)palladium was 0.1 equivalent) were added into a dry two-necked flask. Subsequently, 40 mL of ultradry toluene and 4 mL of ultradry methanol were injected. The reaction system was heated to 95 °C and stirred thoroughly for 12 hours. It was filtered while hot, washed successively with toluene, water, and ethanol, and after drying, a white solid of 0.333 g was obtained by Soxhlet extraction with a yield of 74.2%;

[0055] (3) Ketal deprotection reaction: 0.35 mmol of the product from step (2) was added into a 100 mL flask, and then 50 mL of a mixed solution of trifluoroacetic acid / water = 9:1 was added. The reaction temperature was 95 °C, and it was stirred for 2 days. After cooling to room temperature, it was poured into 1000 mL of ice water, filtered, dried, and the precipitate was collected to obtain 0.205 g of yellow solid 1,3,5-tris(9,10-phenanthrenequinonyl)benzene with a yield of 84.3%.

[0056] Preparation method of 4-phenanthrenequinonyl derivative 1,3,5-tris(9,10-phenanthrenequinonyl)benzene in Example

[0057] (1) Ketalization reaction of carbonyl group: Under the protection of an inert atmosphere, 4.43 mmol of 3-bromo-9,10-phenanthrenequinone and 1.33 mmol of camphorsulfonic acid (the dosage of camphorsulfonic acid is 0.3 equivalent of 3-bromo-9,10-phenanthrenequinone) were put into a Schlenk pressure-resistant bottle, and 35 mL of ethylene glycol was injected. The reaction solvent used was ultra-dry dioxane, and the dosage was 70 mL (the volume ratio of the reaction solvent dioxane to ethylene glycol was 2:1). The reaction system was sealed and stirred continuously at 140 °C for 12 hours. After the system was naturally cooled to room temperature, it was poured into water, allowed to stand and the precipitate was filtered, washed with water, and 1.41 g of a yellowish-brown crude product was collected. After drying, the precipitate was purified by column chromatography, and the eluent was ethyl acetate:petroleum ether volume ratio = 1:20, and 1 g of a white solid was obtained, with a yield of 60.4%;

[0058] (2) Coupling reaction: Under the protection of an inert atmosphere, 1.87 mmol of the product of step (1), 0.46 mmol of 1,3,5-benzenetriboronic acid tris(pinacol) ester, 1.4 mmol of potassium carbonate, and 0.04 mmol of tetrakis(triphenylphosphine)palladium (the feeding amount of 1,3,5-benzenetriboronic acid tris(pinacol) ester was 1 equivalent, the feeding amount of the product of step (1) was 4 equivalents, the feeding amount of potassium carbonate was 3 equivalents, and tetrakis(triphenylphosphine)palladium was 0.1 equivalent) were added to a dry two-necked flask. Subsequently, 40 mL of ultra-dry toluene and 4 mL of ultra-dry methanol were injected. The reaction system was heated to 100 °C and stirred thoroughly for 12 hours. It was filtered while hot, washed successively with toluene, water, and ethanol, and after drying, a white solid of 0.338 g was obtained by Soxhlet extraction, with a yield of 75.2%;

[0059] (3) Ketal deprotection reaction: 0.35 mmol of the product of step (2) was added to a 100 mL flask, and then 50 mL of a mixed solution of trifluoroacetic acid / water = 9:1 was added. The reaction temperature was 100 °C, and it was stirred for 2 days. After cooling to room temperature, it was poured into 1000 mL of ice water, filtered, dried, and the precipitate was collected to obtain 0.216 g of yellow solid 1,3,5-tris(9,10-phenanthrenequinonyl)benzene, with a yield of 88.6%.

[0060] The following are the characterization data of the invention content. The compounds synthesized under different examples were characterized accordingly, and the results were all consistent. Taking the characterization of the products of each step in Example 4 under the preferred conditions as an example, the spectra are as Figure 1 shown. Among them, the infrared spectrum of the phenanthrenequinone derivative TPQB should have a strong carbonyl absorption vibration peak, and the wave number is between 1700 - 1600 cm -1 ; in the mass spectrum, the peak corresponding to the characteristic ion [TPQB + H] + should be 697.1573. The proton nuclear magnetic resonance spectrum of the product in step (1) is as Figure 1 (a) shown; the proton nuclear magnetic resonance spectrum of the product in step (2) is as Figure 1(b); The infrared spectrum of the 1,3,5-tris(9,10-phenanthrenequinonyl)benzene (TPQB) molecules prepared in step (3) is as shown in Figure 1 (c). The acetal structure is located at 1901 cm -1 for C-O-C and the characteristic absorption peak of -CH2- at 2980 cm -1 disappears, and the strong carbonyl absorption peak at 1664 cm -1 reappears, indicating that the carbonyl group reappears after the deacetalization reaction; The mass spectrum of the 1,3,5-tris(9,10-phenanthrenequinonyl)benzene (TPQB) molecules is as shown in Figure 1 (d). The characterized spectral data is consistent with the theoretical values, proving the successful preparation of TPQB.

[0061] Example 5 - Preparation method of TPQB positive electrode

[0062] Use the TPQB prepared in Examples (1 - 4) as the active material of the positive electrode material.

[0063] Preparation of the TPQB positive electrode in a lithium-ion battery: Disperse the prepared TPQB, graphene, and polyvinylidene fluoride in N-methylpyrrolidone at a mass ratio of 6:3:1, stir well to obtain the positive electrode slurry, then coat it on the carbon-coated aluminum foil, dry it at 60 °C for 6 hours, and then use a cutter to roll it into an electrode sheet with a diameter of 9 mm, and then transfer it to the glove box for standby. For the preparation of the Nafion-coated polypropylene separator in a lithium-ion battery, refer to the literature: Adv. Mater. 2022, 34, 2107226.

[0064] Preparation of the TPQB positive electrode in an aqueous zinc-ion battery: Disperse the prepared TPQB, Ketjen black, and polyvinylidene fluoride in N-methylpyrrolidone at a mass ratio of 6:3:1, stir well to obtain the positive electrode slurry, then coat it on the titanium foil, dry it at 60 °C for 6 hours, and then use a cutter to roll it into an electrode sheet with a diameter of 9 mm.

[0065] Example 6 - Assembly and test conditions of lithium-ion batteries

[0066] The assembly of the battery is carried out in a glove box. The battery uses a 2032 type button cell, the Nafion-coated polypropylene separator as the separator, the electrode prepared in Example 5 as the positive electrode, the metallic lithium foil as the negative electrode, the electrolyte uses 2M LiTFSI and 0.6M PEO in DOL / DME (V:V = 1:1). After assembling the battery, place it in a Neware battery test system for electrochemical performance testing. The test voltage range is 1.5 - 3.5 V, and the test current densities are 0.2C and 5C (1C = 231 mAg -1 ), and the current density for the rate performance test gradually increases from 0.2C to 40C.

[0067] Example 7 - Assembly and Testing Conditions of Aqueous Zinc - Ion Battery

[0068] The assembly of the battery was carried out in air. The battery used a 2032 - type coin - cell battery, with glass fiber as the separator, the electrode prepared in Example 5 as the positive electrode, metallic zinc foil as the negative electrode, and 3M Zn(OTf)₂ aqueous solution as the electrolyte. After assembling the battery, it was placed in a Neware battery testing system for electrochemical performance testing. The test voltage range was 0.25 - 1.6 V, the test current densities were 0.1C and 5C, and the current density for the rate performance test increased gradually from 0.5C to 10C.

[0069] The test results of Example 6 are analyzed and discussed as follows. The galvanostatic charge - discharge curves of the TPQB electrode in the lithium - ion battery at 0.2C (attached Figure 2 ), the rate performance at different current densities (attached Figure 3 ), and the long - cycle performance at 5C (attached Figure 4 ). It can be observed from the charge - discharge curves that the initial discharge specific capacity of the TPQB electrode at a current density of 0.2C is as high as 229.8 mAh g -1 (after deducting the capacity of graphene, 17.5 mAh g -1 ), which is basically the same as the theoretical capacity, indicating a high utilization rate of the active sites of the material; in the rate performance test, this electrode has an ultra - fast rate performance of up to 40C, and when returning to 0.2C, the capacity can recover to 94.5% of the initial capacity; in the long - cycle performance test, the prepared TPQB electrode at a high current density of 5C, after 1000 cycles, the capacity retention rate is 76.8%.

[0070] The test results of Example 7 are analyzed and discussed as follows. The galvanostatic charge - discharge curves of the TPQB electrode in the aqueous zinc - ion battery at 0.1C (attached Figure 5 ), the rate performance at different current densities (attached Figure 6 ), and the long - cycle performance at 5C (attached Figure 7 ). It can be observed from the charge - discharge curves that the initial discharge specific capacity of the TPQB electrode at a current density of 0.1C is as high as 225.8 mAh g -1 (after deducting the capacity of Ketjenblack, 12.5 mAh g -1 ), indicating that the material still maintains the advantage of relatively high specific capacity in the aqueous battery system; in the rate performance test, the capacity at a high current density of 10C is 82.6% of the initial capacity at 0.5C, and when the current density returns to 0.5C, the capacity recovers to 97.5% of the initial value; in the long - cycle performance test, the prepared TPQB electrode at a high current density of 5C, after 6000 cycles, the capacity retention rate is as high as 93.2%.

[0071] Overall, in terms of discharge specific capacity, cycle life and rate performance, this electrode exceeds all reported PQ-based organic small molecule cathode materials in both lithium-ion batteries and aqueous zinc-ion battery systems.

[0072] Those skilled in the art should understand that the present invention is not limited by the above embodiments, which are the preferred embodiments of the present invention. Without departing from the spirit and scope of the present invention, various changes and improvements will occur to the present invention, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A phenanthraquinone derivative for a cathode material, characterized in that, The phenanthraquinone-based derivative is 1,3,5-tris(9,10-phenanthraquinonyl)benzene, and its structural formula is:

2. The preparation method of the phenanthraquinone-based derivative of claim 1, characterized in that, The preparation of 1,3,5-tris(9,10-phenanthraquinonyl)benzene includes the following steps: (1) Ketalization reaction of the carbonyl group: Under the protection of an inert atmosphere, add the raw materials 3-bromo-9,10-phenanthraquinone and ethylene glycol into the reaction flask. Under the catalysis of camphorsulfonic acid, add the reaction solvent, seal the reaction system, and react at 139-141 °C for 11-13 hours; after the solution is naturally cooled to room temperature, pour it into water, let it stand and filter the precipitate, wash it with water, collect the crude product, dry it in an oven, and finally purify it by column chromatography to obtain a pure product; (2) Coupling reaction: Use the common reaction system of the Suzuki coupling reaction: Under the protection of an inert atmosphere, use tetrakis(triphenylphosphine)palladium as the catalyst, and add potassium carbonate. Couple the product of step (1) with 1,3,5-benzenetriboronic acid tris(pinacol)ester. Use toluene and methanol as the reaction solvents, react at 95-101 °C for 11-13 hours, then filter the precipitate, wash it successively with toluene, water and ethanol, and purify it by Soxhlet extraction after drying to obtain the product; (3) Ketal deprotection reaction: Put the product of step (2) into the reaction flask, add a mixed solution of trifluoroacetic acid / water, react at 95-102 °C for 2-3 days, then filter the precipitate, wash it with deionized water, and dry it to obtain the target product 1,3,5-tris(9,10-phenanthraquinonyl)benzene.

3. The method according to claim 2, characterized in that, In step (1), the dosage of the catalyst camphorsulfonic acid is 0.3 equivalent of the raw material 3-bromo-9,10-phenanthraquinone; ethylene glycol should be in excess.

4. The method according to claim 2, characterized in that, In step (1), the reaction solvent is methanol or dioxane; the volume ratio of the reaction solvent to ethylene glycol is 2:1; the eluent of the column chromatography method used is ethyl acetate: petroleum ether volume ratio = 1:10-20.

5. The method according to claim 2, wherein In step (2), the feeding of the raw materials is based on 1 equivalent of the feeding of 1,3,5-benzenetriboronic acid tris(pinacol)ester, 4 equivalents of the product feeding in the first step, 3 equivalents of potassium carbonate feeding, and 0.1 equivalent of tetrakis(triphenylphosphine)palladium; the volume ratio of the reaction reagents toluene and methanol used is 40:5-3.

6. The method according to claim 2, wherein In step (3), the volume ratio of trifluoroacetic acid / water is 8-10:

1.

7. The method according to claim 2, characterized in that, The inert atmosphere is nitrogen or argon.

8. The phenanthraquinone-based derivative of claim 1 is used as the positive electrode material of the electrode.

9. The positive electrode material of claim 8 is used in a lithium-ion battery or an aqueous zinc-ion battery.

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