High-capacity green energy storage battery and preparation method thereof

Abstract

The invention relates to a high-capacity green energy storage battery and a preparation method thereof, and belongs to the technical field of energy storage batteries. The anthraquinone active material is prepared, the active material is used as a battery positive active material to prepare a high-capacity green energy storage battery, a plurality of quinonyl groups and imino groups exist in the prepared active material, and a plurality of active centers can remarkably increase the specific capacity of the battery; the electron-withdrawing quinonyl group and the electron-donating imino group can generate a synergistic effect to adjust the overall redox potential of the active substance, a discharge platform is widened to a medium-high voltage interval, the specific capacity and energy density of the active substance are remarkably improved, in addition, the active substance can form strong hydrogen bond stacking, and the specific capacity and energy density of the active substance are remarkably improved. The dissolvability of the active substance in the electrolyte is remarkably reduced, the volume change of the active substance in the charging and discharging process is inhibited, an ordered pi-pi stacking structure is formed, the conductivity of the active substance can be effectively improved, and therefore the use amount of the conductive agent is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage batteries, and in particular, relates to a large-capacity green energy storage battery and a preparation method thereof. Background Art

[0002] As the core technology of modern electrochemical energy storage, the development of lithium-ion energy storage batteries is highly dependent on the innovation of cathode material performance. The inorganic cathode active materials in existing technologies, such as lithium cobalt oxide, lithium iron phosphate or ternary nickel cobalt manganese oxide, have limited theoretical specific capacity (generally less than 200mAh / g). In order to design high-capacity energy storage batteries, it is also necessary to improve the theoretical specific capacity of the cathode active material. Organic cathode materials have become a research hotspot due to their strong molecular structure designability, abundant raw material sources, environmental friendliness and high theoretical specific capacity. Among them, anthraquinone and its derivatives stand out due to their unique redox activity and high theoretical capacity. The core advantage of anthraquinone compounds comes from the multi-electron redox mechanism of their carbonyl group. Each anthraquinone unit can store two lithium ions through the reversible enolization reaction of two carbonyl groups. The theoretical specific capacity generally exceeds 250 mAh / g, which is significantly higher than traditional inorganic materials. However, anthraquinone compounds have low molecular polarity and are easily soluble in conventional organic electrolytes (such as carbonate solvents), resulting in continuous loss of active substances. Anthraquinone compounds have poor intrinsic conductivity and require the addition of more conductive agents. Adding more conductive agents will not only reduce the energy density, but also the intermolecular charge repulsion and structural swelling caused by lithium ion embedding during charging and discharging will significantly inhibit the ion transfer kinetics, resulting in poor cycle stability of anthraquinone compounds. To address the above technical defects, the present invention provides a large-capacity green energy storage battery and a preparation method thereof. Summary of the Invention

[0003] The object of the present invention is to provide a large-capacity green energy storage battery and a preparation method thereof, so as to solve the problems mentioned in the above background technology.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A large-capacity green energy storage battery, comprising an electrolyte, a separator, a graphite negative electrode, and a positive electrode material;

[0006] Furthermore, the electrolyte includes a solvent and a lithium salt, wherein the solvent is a compound of diethyl carbonate and ethylene carbonate, and the lithium salt is lithium bis(fluorosulfonyl)imide.

[0007] Furthermore, the diaphragm is a polypropylene diaphragm.

[0008] Furthermore, the positive electrode material comprises a conductive agent, a binder, a current collector, and an active material, wherein the conductive agent is one of acetylene black, Super P, and Ketjen black, the binder is polyvinylidene fluoride, the current collector is aluminum foil, and the active material is prepared by the following steps:

[0009] S1. Mix 7-bromo-2-hydroxynaphthalene-1,4-dione, 2,3,5,6-tetrakis(amino)-p-benzoquinone, and glacial acetic acid in a three-necked flask equipped with a thermometer, a condenser reflux apparatus, and a rotor. Turn on magnetic stirring, raise the system temperature to 90-110° C., and then keep the temperature to react for 16-32 hours. After the reaction is completed, pour the reaction solution into ice water to cool, filter out the solid, and wash the obtained solid with anhydrous ethanol and deionized water in sequence, and then dry to obtain an intermediate;

[0010]

[0011] S2. Under nitrogen protection, mix the intermediate, 3,5-dinitrophenylboric acid, 1,1'-bis(diphenylphosphinoferrocenepalladium dichloride), sodium hydroxide and dimethyl sulfoxide in a three-necked flask equipped with a thermometer, a condenser reflux device and a rotor, turn on magnetic stirring, raise the system temperature to 100-120°C and keep it warm for 30-40 minutes. After the reaction is completed, cool it to room temperature in an ice-water bath and remove the solvent by rotary evaporation. Wash the remaining solid with anhydrous ethanol and deionized water and dry it to obtain the active material.

[0012]

[0013] Preferably, the mass ratio of 7-bromo-2-hydroxynaphthalene-1,4-dione, 2,3,5,6-tetrakis(amino)-p-benzoquinone, and glacial acetic acid used in S1 is 1-1.6:3-5.4:110-150.

[0014] Preferably, the mass ratio of the intermediate used in S2, 3,5-dinitrophenylboric acid, 1,1'-bis(diphenylphosphinoferrocenedichloropalladium) chloride, sodium hydroxide, and dimethyl sulfoxide is 2.4-3.8: 2-3.8: 0.08-0.152: 2-3.2: 80-100.

[0015] The present invention also discloses a method for preparing the large-capacity green energy storage battery:

[0016] A method for preparing a large-capacity green energy storage battery comprises the following steps:

[0017] Step 1: In an argon-protected glove box, diethyl carbonate and ethylene carbonate were mixed evenly, and lithium salt was added and stirred until completely dissolved to obtain an electrolyte for use;

[0018] Step 2: dissolving the binder in N-methylpyrrolidone to prepare a binder solution for later use;

[0019] Step 3: After mixing the active material and the conductive agent, add them into a planetary mixer and stir to mix. Then, add the mixture into the binder solution, disperse it at high speed to remove bubbles and apply it on the surface of the current collector. After drying, the positive electrode sheet is obtained.

[0020] Step 4: After rolling and cutting the positive electrode and graphite negative electrode into the predetermined shape, they are stacked in the order of negative electrode-diaphragm-positive electrode-diaphragm-negative electrode in an argon-protected glove box and placed in a prefabricated battery casing. After injecting electrolyte and vacuuming, they are sealed to obtain a large-capacity green energy storage battery.

[0021] Preferably, when preparing the electrolyte, the mass ratio of diethyl carbonate, ethylene carbonate and lithium salt is 30-40:60-70:12-18.

[0022] Preferably, when preparing the positive electrode sheet, the mass ratio of the binder, N-methylpyrrolidone, active material, and conductive agent is 6-10:90-110:80-90:4-6.

[0023] Preferably, in the third step, the active material and the conductive agent are stirred and mixed at a rotation speed of 200 to 400 rpm for 10 to 20 minutes.

[0024] Preferably, in the third step, the mixed material is added to the binder solution and dispersed at high speed under the condition of stirring at a rotation speed of 1200-2000 rpm for 2-3 hours.

[0025] Beneficial effects of the present invention:

[0026] 1) The present invention uses 2,3,5,6-tetra(amino)benzoquinone and 7-bromo-2-hydroxynaphthalene-1,4-dione as raw materials, and utilizes the adjacent amino groups of 2,3,5,6-tetra(amino)benzoquinone to react with the adjacent carbonyl groups of 7-bromo-2-hydroxynaphthalene-1,4-dione (keto / enol isomers can be converted into each other) to introduce an imino group to obtain an intermediate with two pyrazine groups. The bromine atom of the intermediate then undergoes a Suzuki-Miyura reaction with the boronic acid group of 3,5-dinitrophenylboronic acid to introduce four nitro groups into the intermediate structure to obtain an active material. The active material of the present invention contains multiple quinone groups and imino groups, and the multiple active centers significantly increase the specific capacity of the battery. In addition, the electron-withdrawing quinone groups and the electron-donating imino groups can also produce a synergistic effect to adjust the overall redox potential of the active material, broaden the discharge platform to the medium and high voltage range, and significantly improve the specific capacity and energy density of the active material.

[0027] 2) The active material of the present invention has a relatively large planar structure, and contains imino, nitro, and quinone groups. The imino groups can form intramolecular and intermolecular hydrogen bonds, while the quinone and nitro groups are good hydrogen bond acceptors. The nitro group not only acts as a hydrogen bond acceptor, but also significantly increases the polarity of the molecule and strengthens the hydrogen bonding between molecules, so that the active material can be tightly combined together through hydrogen bonding to form a more stable crystal structure, significantly reducing the solubility of the active material in the electrolyte and inhibiting the volume change of the active material during the charge and discharge process.

[0028] 3) The introduction of nitro groups into the active material of the present invention significantly improves the polarity of the molecule and the hydrogen bonding effect. As a strong electron-withdrawing group, the nitro group can significantly reduce the LUMO energy level of the core of the active material, while hydrogen bond accumulation can form an ordered π-π stacking structure, which helps to improve the conductive properties of the active material, thereby reducing the amount of conductive agent used. DETAILED DESCRIPTION

[0029] It should be understood that the expression "one or more of" includes individually each of the items recited after the expression and various combinations of two or more of the recited items, unless otherwise apparent from the context and usage. The expression "and / or" in conjunction with three or more recited items should be understood to have the same meaning, unless otherwise apparent from the context.

[0030] The terms "comprising", "having" or "containing", including their grammatical synonyms, should generally be understood as open and non-restrictive, e.g., not excluding other unrecited elements or steps, unless otherwise specifically stated or understood from the context.

[0031] It should be understood that the order of steps or the order in which certain actions are performed are not important as long as the present invention remains operable. Additionally, two or more steps or actions may be performed simultaneously.

[0032] The use of any and all examples or exemplary language, such as "such as" or "including," herein is intended merely to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0033] Example 1

[0034] A large-capacity green energy storage battery, comprising an electrolyte, a separator, a graphite negative electrode, and a positive electrode material;

[0035] The electrolyte includes a solvent and a lithium salt, and the solvent is a compound of diethyl carbonate and ethylene carbonate, and the lithium salt is lithium bis(fluorosulfonyl)imide. The separator is a polypropylene separator, and the positive electrode material includes a conductive agent, a binder, a current collector, and an active material. The conductive agent is acetylene black, the binder is polyvinylidene fluoride, and the current collector is aluminum foil. The active material is prepared by the following steps:

[0036] S1. Mix 1 g of 7-bromo-2-hydroxynaphthalene-1,4-dione, 3 g of 2,3,5,6-tetrakis(amino)-p-benzoquinone, and 110 g of glacial acetic acid in a three-necked flask equipped with a thermometer, a condensing reflux apparatus, and a rotor. Turn on magnetic stirring, raise the system temperature to 90° C., and then keep the temperature to react for 32 hours. After the reaction is completed, pour the reaction solution into ice water to cool, filter out the solid, and wash the obtained solid with anhydrous ethanol and deionized water in sequence, and then dry to obtain an intermediate;

[0037] S2. Under nitrogen protection, 2.4 g of the intermediate, 2 g of 3,5-dinitrophenylboric acid, 0.08 g of 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, 2 g of sodium hydroxide, and 80 g of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a condensation reflux device and a rotor. The magnetic stirring was turned on, and the system temperature was raised to 100°C and kept warm for 40 minutes. After the reaction was completed, the mixture was cooled to room temperature in an ice-water bath and the solvent was removed by rotary evaporation. The remaining solid was washed with anhydrous ethanol and deionized water and then dried to obtain the active material.

[0038] A method for preparing a large-capacity green energy storage battery comprises the following steps:

[0039] Step 1: In an argon-protected glove box, 30 parts by mass of diethyl carbonate and 70 parts by mass of ethylene carbonate were mixed evenly, and then 12 parts of lithium bis(fluorosulfonyl)imide were added and stirred until completely dissolved to obtain an electrolyte for use;

[0040] Step 2: Dissolve 6 parts of polyvinylidene fluoride in 90 parts of N-methylpyrrolidone to prepare a binder solution for later use;

[0041] Step 3: 80 parts of active material and 4 parts of acetylene black were mixed by weight and added to a planetary mixer and stirred at 200 rpm for 20 minutes. The mixture was then added to the binder solution and stirred at 1200 rpm for 3 hours. After removing bubbles, the mixture was coated on the surface of aluminum foil and dried to obtain a positive electrode sheet.

[0042] Step 4: After rolling and cutting the positive electrode and graphite negative electrode into the predetermined shape, they are stacked in the order of negative electrode-diaphragm-positive electrode-diaphragm-negative electrode in an argon-protected glove box and placed in a prefabricated battery casing. After injecting electrolyte and vacuuming, they are sealed to obtain a large-capacity green energy storage battery.

[0043] Example 2

[0044] A large-capacity green energy storage battery, comprising an electrolyte, a separator, a graphite negative electrode, and a positive electrode material;

[0045] The electrolyte includes a solvent and a lithium salt, and the solvent is a compound of diethyl carbonate and ethylene carbonate, the lithium salt is lithium bis(fluorosulfonyl)imide, the separator is a polypropylene separator, the positive electrode material includes a conductive agent, a binder, a current collector and an active material, and the conductive agent is Super P, the binder is polyvinylidene fluoride, the current collector is aluminum foil, and the active material is prepared by the following steps:

[0046] S1. 1.3 g of 7-bromo-2-hydroxynaphthalene-1,4-dione, 4.2 g of 2,3,5,6-tetrakis(amino)-p-benzoquinone, and 130 g of glacial acetic acid were mixed in a three-necked flask equipped with a thermometer, a condensing reflux apparatus, and a rotor. The magnetic stirring was turned on, and the system temperature was raised to 100 ° C. and then kept warm for 24 hours. After the reaction was completed, the reaction solution was poured into ice water for cooling, and then the solid was filtered out and the obtained solid was washed with anhydrous ethanol and deionized water in sequence and dried to obtain an intermediate;

[0047] S2. Under nitrogen protection, 3.1 g of the intermediate, 2.9 g of 3,5-dinitrophenylboric acid, 0.116 g of 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, 2.6 g of sodium hydroxide, and 90 g of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a condenser reflux device, and a rotor. The magnetic stirring was turned on, and the system temperature was raised to 110°C and kept warm for 35 minutes. After the reaction was completed, the system was cooled to room temperature in an ice-water bath and the solvent was removed by rotary evaporation. The remaining solid was washed with anhydrous ethanol and deionized water and dried to obtain the active material.

[0048] A method for preparing a large-capacity green energy storage battery comprises the following steps:

[0049] Step 1: In an argon-protected glove box, 35 parts by mass of diethyl carbonate and 65 parts by mass of ethylene carbonate were mixed evenly, and then 15 parts of lithium bis(fluorosulfonyl)imide was added and stirred until completely dissolved to obtain an electrolyte for use;

[0050] Step 2: dissolving 8 parts of polyvinylidene fluoride in 100 parts of N-methylpyrrolidone to prepare a binder solution for later use;

[0051] Step 3: 85 parts of active material and 5 parts of Super P were mixed by mass and added to a planetary mixer and stirred at 300 rpm for 15 minutes. The mixture was then added to the binder solution and stirred at 1600 rpm for 2.5 hours. After removing bubbles, the mixture was coated on the surface of aluminum foil and dried to obtain the positive electrode sheet.

[0052] Step 4: After rolling and cutting the positive electrode and graphite negative electrode into the predetermined shape, they are stacked in the order of negative electrode-diaphragm-positive electrode-diaphragm-negative electrode in an argon-protected glove box and placed in a prefabricated battery casing. After injecting electrolyte and vacuuming, they are sealed to obtain a large-capacity green energy storage battery.

[0053] Example 3

[0054] A large-capacity green energy storage battery, comprising an electrolyte, a separator, a graphite negative electrode, and a positive electrode material;

[0055] The electrolyte includes a solvent and a lithium salt, and the solvent is a compound of diethyl carbonate and ethylene carbonate, the lithium salt is lithium bis(fluorosulfonyl)imide, the separator is a polypropylene separator, the positive electrode material includes a conductive agent, a binder, a current collector and an active material, and the conductive agent is Ketjen black, the binder is polyvinylidene fluoride, the current collector is aluminum foil, and the active material is prepared by the following steps:

[0056] S1, 1.6g 7-bromo-2-hydroxynaphthalene-1,4-dione, 5.4g 2,3,5,6-tetrakis(amino)-p-benzoquinone, and 150g glacial acetic acid were mixed in a three-necked flask equipped with a thermometer, a condensing reflux apparatus, and a rotor, and magnetic stirring was turned on. The system temperature was raised to 110°C and then kept warm for 16h. After the reaction was completed, the reaction solution was poured into ice water for cooling, and then the solid was filtered out and the obtained solid was washed with anhydrous ethanol and deionized water in sequence and dried to obtain an intermediate;

[0057] S3. Under nitrogen protection, 3.8 g of intermediate 2, 3.8 g of 3,5-dinitrophenylboric acid, 0.152 g of 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, 3.2 g of sodium hydroxide, and 100 g of dimethyl sulfoxide were mixed in a three-necked flask equipped with a thermometer, a condenser reflux device, and a rotor. The magnetic stirring was turned on, and the system temperature was raised to 120°C and kept warm for 30 minutes. After the reaction was completed, the mixture was cooled to room temperature in an ice-water bath and the solvent was removed by rotary evaporation. The remaining solid was washed with anhydrous ethanol and deionized water and dried to obtain the active material.

[0058] A method for preparing a large-capacity green energy storage battery comprises the following steps:

[0059] Step 1: In an argon-protected glove box, 40 parts by mass of diethyl carbonate and 60 parts by mass of ethylene carbonate were mixed evenly, and then 18 parts of lithium bis(fluorosulfonyl)imide was added and stirred until completely dissolved to obtain an electrolyte for use;

[0060] Step 2: Dissolve 10 parts of polyvinylidene fluoride in 110 parts of N-methylpyrrolidone to prepare a binder solution for later use;

[0061] Step 3: 90 parts of active material and 6 parts of Ketjen black were mixed by mass and added to a planetary mixer and stirred at 400 rpm for 10 minutes. The mixture was then added to the binder solution and stirred at 2000 rpm for 2 hours. After removing bubbles, the mixture was coated on the surface of aluminum foil and dried to obtain a positive electrode sheet.

[0062] Step 4: After rolling and cutting the positive electrode and graphite negative electrode into the predetermined shape, they are stacked in the order of negative electrode-diaphragm-positive electrode-diaphragm-negative electrode in an argon-protected glove box and placed in a prefabricated battery casing. After injecting electrolyte and vacuuming, they are sealed to obtain a large-capacity green energy storage battery.

[0063] Comparative Example 1

[0064] The active substance in Example 2 was replaced by 1,4,5,8-tetrahydroxyanthraquinone, and the other raw materials and preparation steps remained unchanged.

[0065] A large-capacity green energy storage battery, comprising an electrolyte, a separator, a graphite negative electrode, and a positive electrode material;

[0066] Among them, the electrolyte includes a solvent and a lithium salt, and the solvent is a compound of diethyl carbonate and ethylene carbonate, the lithium salt is lithium bis(fluorosulfonyl)imide, the diaphragm is a polypropylene diaphragm, the positive electrode material includes a conductive agent, a binder, a current collector and an active substance, and the conductive agent is Super P, the binder is polyvinylidene fluoride, the current collector is aluminum foil, and the active material is 1,4,5,8-tetrahydroxyanthraquinone.

[0067] A method for preparing a large-capacity green energy storage battery comprises the following steps:

[0068] Step 1: In an argon-protected glove box, 35 parts by mass of diethyl carbonate and 65 parts by mass of ethylene carbonate were mixed evenly, and then 15 parts of lithium bis(fluorosulfonyl)imide was added and stirred until completely dissolved to obtain an electrolyte for use;

[0069] Step 2: dissolving 8 parts of polyvinylidene fluoride in 100 parts of N-methylpyrrolidone to prepare a binder solution for later use;

[0070] Step 3: 85 parts of active material and 5 parts of Super P were mixed by mass and added to a planetary mixer and stirred at 300 rpm for 15 minutes. The mixture was then added to the binder solution and stirred at 1600 rpm for 2.5 hours. After removing bubbles, the mixture was coated on the surface of aluminum foil and dried to obtain the positive electrode sheet.

[0071] Step 4: After rolling and cutting the positive electrode and graphite negative electrode into the predetermined shape, they are stacked in the order of negative electrode-diaphragm-positive electrode-diaphragm-negative electrode in an argon-protected glove box and placed in the prefabricated battery shell. The electrolyte is injected and the shell is sealed after vacuuming to obtain a large-capacity green energy storage battery.

[0072] Experimental Example 1

[0073] The performance tests of the large-capacity green energy storage batteries in Examples 1 to 3 and Comparative Example 1 were performed using an electrochemical workstation. The discharge platform width, specific capacity, energy density, and capacity retention rate after 500 cycles of each component battery were tested. The test results are shown in Table 1:

[0074] Table 1

[0075] project Discharge platform width (V) Specific capacity (mAh / g) Energy density (Wh / kg) Capacity retention rate (%) Example 1 0.42 349mAh / g 746Wh / kg 85.3 Example 2 0.45 362mAh / g 764Wh / kg 86.2 Example 3 0.42 346mAh / g 742Wh / kg 85.4 Comparative Example 1 0.26 186mAh / g 442Wh / kg 20.6

[0076] As can be seen from Table 1, the large-capacity green energy storage batteries in Examples 1 to 3 of the present invention have better electrical properties. However, in the energy storage battery in Comparative Example 1, since the active material has not been modified, the amount of conductive agent is insufficient to maintain the electron transmission path, resulting in a serious impact on the specific capacity and cycle stability. In summary, the active material of the present invention has a wider discharge platform width and higher energy density when used in energy storage batteries, and has good cycle stability. It has certain conductive properties, can reduce the amount of conductive agent used, and can effectively increase the capacity of the battery when used to prepare energy storage batteries.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A large-capacity green energy storage battery, characterized in that: Contains electrolyte, diaphragm, graphite negative electrode, positive electrode materials; The positive electrode material includes a conductive agent, a binder, a current collector, and an active material, and the active material is prepared by the following steps: 7-bromo-2-hydroxynaphthalene-1,4-dione, 2,3,5,6-tetrakis(amino)-p-benzoquinone and glacial acetic acid are mixed and the temperature is controlled at 90-110°C to react to obtain an intermediate; the intermediate, 3,5-dinitrophenylboric acid, 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride, sodium hydroxide and dimethyl sulfoxide are mixed and the temperature is controlled at 100-120°C to react to obtain an active material.

2. A large-capacity green energy storage battery according to claim 1, characterized in that: The electrolyte comprises a solvent and a lithium salt, wherein the solvent is prepared by compounding diethyl carbonate and ethylene carbonate, and the lithium salt is lithium bis(fluorosulfonyl)imide.

3. A large-capacity green energy storage battery according to claim 1, characterized in that: The separator is a polypropylene separator, the conductive agent is one of acetylene black, Super P, and Ketjen black, the binder is polyvinylidene fluoride, and the current collector is aluminum foil.

4. A large-capacity green energy storage battery according to claim 1, characterized in that: The mass ratio of 7-bromo-2-hydroxynaphthalene-1,4-dione, 2,3,5,6-tetrakis(amino)-p-benzoquinone and glacial acetic acid is 1-1.6:3-5.4:110-150.

5. A large-capacity green energy storage battery according to claim 1, characterized in that: The mass ratio of the intermediate 2, 3,5-dinitrophenylboric acid, 1,1'-bis(diphenylphosphinoferrocenedichloropalladium) chloride, sodium hydroxide and dimethyl sulfoxide is 1.2-1.8: 1-1.8: 0.04-0.072: 1-1.6: 80-100.

6. A method for preparing a large-capacity green energy storage battery according to any one of claims 1 to 5, characterized in that: The following steps are involved: Under argon protection, diethyl carbonate, ethylene carbonate and lithium salt are mixed to obtain an electrolyte for use; a binder is dissolved in N-methylpyrrolidone to obtain a binder solution, and then the active material and the conductive agent are stirred and mixed and added to the binder solution. After high-speed dispersion, bubbles are removed and the mixture is coated on the surface of the current collector, and dried to obtain a positive electrode sheet; the positive electrode sheet and the graphite negative electrode are rolled and cut, and then stacked under argon protection and placed in a battery casing. After the electrolyte is injected and the casing is vacuum-sealed, a large-capacity green energy storage battery can be obtained.

7. The method for preparing a large-capacity green energy storage battery according to claim 6, characterized in that: When preparing the electrolyte, the mass ratio of diethyl carbonate, ethylene carbonate and lithium salt is 30-40:60-70:12-18.

8. The method for preparing a large-capacity green energy storage battery according to claim 6, characterized in that: When preparing the positive electrode sheet, the mass ratio of the binder, N-methylpyrrolidone, active material and conductive agent is 6-10:90-110:80-90:4-6.

9. The method for preparing a large-capacity green energy storage battery according to claim 6, characterized in that: The active material and the conductive agent are stirred and mixed at a rotation speed of 200 to 400 rpm for 10 to 20 minutes.

10. The method for preparing a large-capacity green energy storage battery according to claim 6, characterized in that: The conditions for high-speed dispersion after the mixed material is added to the binder solution are stirring at a rotation speed of 1200 to 2000 rpm for 2 to 3 hours.

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