Disordered rock salt Li3V2O5 fast charge negative electrode material as well as preparation method and application thereof

Abstract

The invention discloses a disordered rock salt Li3V2O5 fast-charging negative electrode material as well as a preparation method and application thereof, and belongs to the field of lithium ion battery fast-charging negative electrode materials. The preparation method comprises the following steps: dispersing a vanadium source in an organic solvent to obtain a solution A with the vanadium source concentration of 0.01 mol / L-0. 2mol / L, uniformly stirring the solution A, and carrying out a first solvothermal reaction at 180-240 DEG C for 0.5-12 hours; after the first solvothermal reaction is finished, sequentially adding a lithium source and a reducing agent into the obtained solution, and continuously stirring to obtain a precursor solution; wherein the molar ratio of the vanadium source to the lithium source is (1: 1.4)-(1: 1.6), and the concentration of the reducing agent is 0.1-0.5 mol / L; the precursor solution is subjected to a second solvothermal reaction for 12-72 h at the temperature of 200-250 DEG C; and after the second solvothermal reaction is finished, cooling, centrifugally washing, drying and grinding the obtained product to obtain the disordered rock salt Li3V2O5 fast charge negative electrode material. The problems that in the existing preparation process, chemical lithiation reaction conditions are harsh, safety is poor, storage and transportation are difficult, and the electrochemical lithiation technological process is complex are solved.

Description

Technical Field

[0001] The present invention belongs to the field of fast-charging negative electrode materials for lithium-ion batteries, and specifically relates to a disordered rock salt Li3V2O5 fast-charging negative electrode material and a preparation method and application thereof. Background Art

[0002] The anode material is a crucial factor influencing charging speed. The slow lithium insertion process and low lithium insertion potential of commercial graphite anodes make them susceptible to severe lithium plating during fast charging. Disordered rock salt Li3V2O5 anode materials are considered highly promising fast-charging anode materials due to their extremely fast charging speed, low lithium insertion potential, and cycling stability. However, existing preparation methods for Li3V2O5 materials still present several challenges. Currently, Li3V2O5 materials are primarily produced through chemical or electrochemical lithiation of V2O5. Chemical lithiation requires the use of highly reactive organolithium reagents, which must be isolated from water and oxygen. Furthermore, organolithium reagents are flammable and explosive, placing stringent storage and transportation requirements on these reagents. Electrochemical lithiation, on the other hand, involves forming V2O5 into electrode sheets, assembling them with lithium metal into a battery, and then discharging the battery at a specific voltage to complete the insertion of excess lithium ions into the V2O5. After the reaction is complete, the battery is disassembled to yield the Li3V2O5 material. Electrochemical lithiation involves both assembly and disassembly of the battery, resulting in a complex process. Summary of the Invention

[0003] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a disordered rock salt Li3V2O5 fast-charging negative electrode material and its preparation method and application, so as to solve the problems of harsh chemical lithiation reaction conditions, poor safety, difficult storage and transportation, and complex electrochemical lithiation process in the existing preparation process.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material comprises the following steps:

[0006] S1. Dispersing a vanadium source in an organic solvent to obtain a solution A having a vanadium source concentration of 0.01 mol / L-0.2 mol / L, stirring the solution A uniformly, and then performing a first solvothermal reaction at 180-240° C. for 0.5-12 h;

[0007] S2. After the first solvothermal reaction is completed, a lithium source and a reducing agent are sequentially added to the resulting solution, and stirring is continued to obtain a precursor solution;

[0008] The molar ratio of the vanadium source to the lithium source is (1:1.4)-(1:1.6), and the concentration of the reducing agent is 0.1-0.5 mol / L;

[0009] S3, subjecting the precursor solution to a second solvothermal reaction at 200-250° C. for 12-72 h;

[0010] S4. After the second solvothermal reaction is completed, the obtained product is cooled, centrifugally washed, dried, and ground to obtain a disordered rock salt Li3V2O5 fast-charging negative electrode material.

[0011] Furthermore, in step S1, the vanadium source is any one of ammonium metavanadate, vanadium chloride, vanadium acetylacetonate, and vanadium pentoxide, and the organic solvent is any one of ethanol, isopropanol, ethylene glycol, and methanol.

[0012] Furthermore, in step S2, the lithium source is any one of lithium hydroxide and its hydrate, lithium chloride, lithium nitrate, and lithium acetate, and the reducing agent is any one of hydrazine hydrate and hydroxylamine hydrochloride.

[0013] Furthermore, the molar ratio of the vanadium source to the lithium source is preferably 1:1.48-1:1.52.

[0014] Furthermore, in step S4, the drying method is to dry the mixture in a vacuum drying oven at 80° C. for 12 hours.

[0015] Furthermore, the steps S1 and S2 are performed under sealed conditions to isolate oxygen.

[0016] Furthermore, the steps S1 and S2 are performed under air atmosphere, and the step S3 is performed by bubbling an inert gas to deoxygenate the precursor solution before the second solvothermal reaction.

[0017] Furthermore, the inert gas is one or more of argon, nitrogen and helium.

[0018] A disordered rock salt Li3V2O5 fast-charging negative electrode material is obtained according to the above preparation method. The disordered rock salt Li3V2O5 fast-charging negative electrode material has a regular block morphology and a thickness of 1 to 5 μm.

[0019] A lithium-ion battery comprises the disordered rock salt Li3V2O5 fast-charging negative electrode material.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention is the first to prepare disordered rock salt Li3V2O5 material through a solvothermal method, which has a simple process route and high yield. The preparation process does not require the use of highly hazardous organic lithium reagents and avoids the tedious battery assembly and disassembly steps of electrochemical lithiation, allowing the Li3V2O5 material to be directly prepared. The present invention can regulate the composition, morphology, and microstructure of the obtained material by adjusting the dissolution thermal reaction process parameters. The Li3V2O5 obtained by the preparation method of the present invention has a regular cubic morphology and good structural stability. At the same time, the (200) crystal plane is fully exposed, which helps to promote the rapid insertion / deinsertion process of lithium ions. The Li3V2O5 obtained by the preparation method of the present invention has high crystallinity, can avoid the lattice defects generated by existing chemical lithiation and electrochemical lithiation methods, and helps to improve the material's cycle stability and high current charge and discharge capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the XRD pattern of the negative electrode material obtained in Example 1 of the present invention;

[0023] Figure 2 This is an SEM image of the negative electrode material obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0025] The first aspect of the present disclosure provides a negative electrode material, the physical phase of which is Li3V2O5. The Li3V2O5 is a lithium-rich disordered rock salt phase composed of three elements: lithium, vanadium, and oxygen. The disordered rock salt Li3V2O5 fast-charging negative electrode material has a regular block morphology and a thickness of 1 to 5 μm.

[0026] The second aspect of the present disclosure provides a method for preparing the above-mentioned negative electrode material, the technical solution is:

[0027] A method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material comprises the following steps: dispersing a vanadium source in an organic solvent to obtain a solution A having a vanadium source concentration of 0.01 mol / L-0.2 mol / L; stirring the solution uniformly; and conducting a first solvothermal reaction at 180-240°C for 0.5-12 h. After the reaction, opening a reactor, adding a lithium source and a reducing agent, and continuously stirring the solution to obtain a precursor solution. The precursor solution is subjected to a second solvothermal reaction at 200-250°C for 12-72 h. After the reaction, the solution is cooled, centrifuged, washed, dried, and ground to obtain the fast-charging negative electrode material.

[0028] Furthermore, the vanadium source is any one of ammonium metavanadate, vanadium chloride, vanadium acetylacetonate, and vanadium pentoxide, and the organic solvent is any one of ethanol, isopropanol, ethylene glycol, and methanol.

[0029] Furthermore, the lithium source is any one of lithium hydroxide and its hydrate, lithium chloride, lithium nitrate, and lithium acetate; and the molar ratio of the vanadium source to the lithium source is (1:1.4)-(1:1.6).

[0030] Furthermore, the reducing agent is any one of hydrazine hydrate and hydroxylamine hydrochloride

[0031] Furthermore, the operation is carried out under closed conditions that isolate oxygen.

[0032] Furthermore, the operation is carried out in an air atmosphere, and the precursor solution is deoxygenated by bubbling an inert gas before the second solvothermal reaction.

[0033] Furthermore, the inert gas used in the bubbling operation is one or more of argon, nitrogen and helium;

[0034] Furthermore, the drying method is to dry in a vacuum drying oven at 80° C. for 12 hours.

[0035] A third aspect of the present disclosure provides a negative electrode, comprising the negative electrode material described in the first aspect of the present disclosure.

[0036] The negative electrode material provided by the present disclosure includes a copper foil current collector and a negative electrode coating, wherein the negative electrode coating includes the negative electrode material, a conductive agent and a binder;

[0037] Furthermore, based on the total weight of the negative electrode coating, the content of the negative electrode material is 60-90% by weight, the content of the conductive agent is 30-10% by weight, and the balance is the negative electrode binder;

[0038] Furthermore, the thickness of the negative electrode coating is 15-100 um, preferably 20-50 um.

[0039] The negative electrode conductive agent and binder disclosed herein can be materials commonly used in the art. For example, the conductive agent can be one or more of acetylene black, Super P, Ketjen black, multi-walled carbon nanotubes, and single-walled carbon nanotubes; the binder can be one or more of carboxymethyl cellulose, polyacrylic acid, and polyvinylidene fluoride. The solvents used are deionized water and N-methylpyrrolidone. The negative electrode coating can be obtained using conventional slurry coating methods, and the coating can be performed using conventional procedures.

[0040] A fourth aspect of the present disclosure provides a lithium-ion battery comprising the negative electrode described in the third aspect of the present disclosure.

[0041] The lithium-ion battery also includes a positive electrode, a separator and an electrolyte, etc., which can be of the types conventionally selected in the field. For example, the positive electrode can be made of lithium sheet, lithium cobalt oxide, lithium iron phosphate, ternary material, etc.; the separator can be made of Celgard2400 polypropylene film and polyethylene, etc.; the electrolyte includes lithium salt, solvent and additives, among which lithium salt can use lithium fluorophosphate, electrolyte solvent can use ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, etc., and additives can use fluoroethylene carbonate, lithium fluorosulfonate, etc.

[0042] In the present disclosure, the lithium-ion battery is assembled using conventional methods in the art.

[0043] Example 1

[0044] (1) Weigh 2 mmol of analytically pure ammonium metavanadate and disperse it in 70 mL of anhydrous ethanol at a concentration of 0.0286 mol / L. After stirring for 0.5 h, a light yellow transparent solution A is formed. Solution A is transferred to a polystyrene-lined stainless steel outer reactor for the first solvothermal reaction at 240°C for 1 h.

[0045] (2) After the reaction is completed and cooled to room temperature, the reactor is opened in a glove box; 3 mmol of lithium hydroxide monohydrate is added to the reactor, and the molar ratio of ammonium metavanadate to lithium hydroxide monohydrate is 1:1.5; stirring is continued for 0.5 h to obtain suspension B; 1 mL of hydrazine hydrate is added to suspension B, the concentration of which is 0.23 mol / L, and stirring is continued for 0.5 h to obtain precursor solution C;

[0046] (3) The above steps (1) and (2) were carried out under airtight conditions to isolate oxygen. The polystyrene liner containing the precursor solution C was placed in the stainless steel outer kettle to carry out a second solvothermal reaction at a temperature of 200°C for 60 hours.

[0047] (4) After the reaction is completed and cooled to room temperature, the precipitate is separated by centrifugation and washed with anhydrous ethanol; the washed product is placed in a vacuum drying oven and dried at 80°C for 12 hours; the dried sample is ground to obtain the Li3V2O5 fast-charging negative electrode material.

[0048] The XRD pattern of the negative electrode material obtained in this embodiment is shown in FIG. Figure 1 As shown, from Figure 1 It can be seen that the diffraction peak position is completely consistent with the reported Li3V2O5, indicating that the Li3V2O5 material was successfully prepared.

[0049] The SEM image of the negative electrode material obtained in this example is as follows Figure 2 As shown, from Figure 2It can be seen that the material presents a regular block morphology with a thickness of 3.5 μm. It has higher structural stability and is conducive to improving the cycle life of the battery.

[0050] Example 2

[0051] This embodiment refers to the method in Example 1, and differs from Example 1 in that:

[0052] The vanadium source used was vanadium chloride, the lithium source used was lithium chloride, the organic solvent was isopropanol, and the remaining process was the same as in Example 1 to prepare the negative electrode material.

[0053] Example 3

[0054] This embodiment refers to the method in Example 1, and differs from Example 1 in that:

[0055] The lithium source used was lithium nitrate, the first solvothermal reaction temperature was 180° C., and the reaction time was 12 h. The remaining process was the same as in Example 1 to prepare the negative electrode material.

[0056] Example 4

[0057] This embodiment refers to the method in Example 1, and differs from Example 1 in that:

[0058] The vanadium source used was vanadium acetylacetonate, the second solvothermal reaction temperature was 250° C., and the reaction time was 12 h. The remaining process was the same as in Example 1 to prepare the negative electrode material.

[0059] Example 5

[0060] This embodiment refers to the method in Example 1, and differs from Example 1 in that:

[0061] The second solvothermal reaction temperature was 200°C and the reaction time was 72 h. Steps (1) and (2) were carried out in an air atmosphere. Step (3) was to deoxygenate the precursor by bubbling nitrogen for 10 min. The remaining process was the same as in Example 1 to prepare the negative electrode material.

[0062] Comparative Example 1

[0063] This comparative example follows the method of Example 1, except that the first solvothermal reaction was omitted and lithium hydroxide and hydrazine hydrate were directly added to the ammonium metavanadate solution for a second solvothermal reaction. The remaining operations were the same as in Example 1 to prepare a non-disordered rock salt phase mixture.

[0064] The XRD pattern of the material obtained in this comparative example is as follows Figure 1 As shown, from Figure 1As can be seen from the figure, the obtained product is not a disordered rock salt phase material, but a mixture of V2O3 and Li3VO4. Compared with Example 1, it can be seen that the step-by-step solvothermal technology disclosed in the present invention is the key to preparing the disordered Li3V2O5 rock salt material.

[0065] Test Case

[0066] This test example is used to illustrate the application effect of the negative electrode material prepared in Example 1 in a lithium-ion battery.

[0067] The negative electrode material obtained in Example 1, acetylene black (conductive agent), and polyvinylidene fluoride (binder) were uniformly mixed in a mass ratio of 6:3:1 using N-methylpyrrolidone as a solvent to obtain a slurry. The slurry was then coated onto a copper foil current collector and placed in a vacuum drying oven at 80°C for 12 hours to obtain a negative electrode. The negative electrode included a negative electrode coating containing 60% by weight of the negative electrode material, 30% by weight of the conductive agent, and 10% by weight of the binder.

[0068] The lithium sheet was used as the positive electrode, Celgard 2400 polypropylene film was used as the battery separator, and the electrolyte was a mixed solution of 1 mol / L lithium hexafluorophosphate in ethylene carbonate (EC) and dimethyl carbonate (DMC) (solvent volume ratio of 1:1) as the electrolyte.

[0069] The positive and negative electrode materials, separator and electrolyte were assembled into CR2032 button batteries using conventional methods in the art.

[0070] The electrochemical performance of the Li₃V₂O₅ anode material was tested using a Xinwei battery testing system. The assembled button-type cells were discharged at a constant current density of 100 mA / g to 0.01 V at room temperature, and then charged at a constant current density of 100 mA / g to 2.0 V. The first-cycle discharge and charge specific capacities were recorded. Cycling tests were then performed using this process, and the capacity retention after 100 cycles was calculated.

[0071] Rate performance test: The assembled button cell was discharged at a constant current density of 100 mA / g to 0.01 V at room temperature, and then charged at a constant current density of 100 mA / g to 2.0 V. The charging capacity and time required at different current densities were recorded.

[0072] The test results of the negative electrode material obtained in Example 1 used in lithium ion batteries are summarized in Table 1 and Table 2 below. Table 1 Cycling performance of the negative electrode material obtained in Example 1 in lithium ion batteries

[0073]

[0074] Table 2 Rate performance of the negative electrode material obtained in Example 1 in lithium-ion batteries and the time required to complete a charge

[0075] Current density (A / g) Charge specific capacity (mAh / g) Time required to complete a charge 0.1 279.0 2h46min 0.2 255.9 1h10min 0.5 230.2 28min 1 215.4 13min 2 194.9 6min 5 136.0 1.65min

[0076] Test data reveals that the material's initial charge and discharge capacity is low, but after 100 cycles, the capacity stabilizes at 277 mAh / g, demonstrating stable cycling performance. More importantly, test data at high current densities demonstrates that the material prepared by this invention exhibits excellent fast-charging performance. For example, at a current density of 5 A / g, it takes only 1.65 minutes to fully charge, demonstrating superior fast-charging performance.

[0077] Example 6

[0078] (1) Weigh 0.35 mmol of vanadium pentoxide and disperse it in 70 mL of ethylene glycol at a concentration of 0.005 mol / L. Stir for 0.5 h to form a suspension A. Transfer the suspension A to a polystyrene-lined reactor with a stainless steel outer reactor and react at 200°C for 8 h.

[0079] (2) After the reaction is completed and cooled to room temperature, the reactor is opened in a glove box; 1.12 mmol of lithium nitrate is added to the reactor, wherein the molar ratio of vanadium pentoxide to lithium nitrate is 0.5:1.6; stirring is continued for 0.5 h to obtain suspension B; 0.43 mL of hydrazine hydrate is added to suspension B, the concentration of which is 0.1 mol / L, and stirring is continued for 0.5 h to obtain precursor C;

[0080] (3) Steps (1) and (2) were carried out in an air atmosphere. The precursor solution C was deoxygenated by nitrogen bubbling for 10 min. The polystyrene liner containing the precursor solution C was placed in a stainless steel outer kettle and subjected to a second solvothermal reaction at a reaction temperature of 250° C. for 12 h.

[0081] (4) After the reaction is completed and cooled to room temperature, the precipitate is separated by centrifugation and washed with anhydrous ethanol; the washed product is placed in a vacuum drying oven and dried at 80°C for 12 hours; the dried sample is ground to obtain the Li3V2O5 fast-charging negative electrode material.

[0082] Example 7

[0083] (1) Weigh 14 mmol of vanadium acetylacetonate and disperse it in 70 mL of methanol at a concentration of 0.2 mol / L. After stirring for 0.5 h, a blue-green transparent solution A is formed. Solution A is transferred to a polystyrene-lined reactor with a stainless steel outer reactor and reacted at 180°C for 12 h.

[0084] (2) After the reaction is completed and cooled to room temperature, the reactor is opened in a glove box; 20.72 mmol of lithium acetate is added to the reactor, and the molar ratio of vanadium acetylacetonate to lithium acetate is 1:1.48; stirring is continued for 0.5 h to obtain suspension B; 2.43 g of hydroxylamine hydrochloride is added to suspension B at a concentration of 0.5 mol / L, and stirring is continued for 0.5 h to obtain precursor C;

[0085] (3) Steps (1) and (2) were carried out in an air atmosphere. The precursor solution C was deoxygenated by bubbling helium for 10 min. The polystyrene liner containing the precursor solution C was placed in a stainless steel outer kettle and subjected to a second solvothermal reaction at a reaction temperature of 220° C. for 72 h.

[0086] (4) After the reaction is completed and cooled to room temperature, the precipitate is separated by centrifugation and washed with anhydrous ethanol; the washed product is placed in a vacuum drying oven and dried at 80°C for 12 hours; the dried sample is ground to obtain the Li3V2O5 fast-charging negative electrode material.

[0087] Example 8

[0088] (1) Weigh 7 mmol of vanadium chloride and disperse it in 70 mL of isopropanol at a concentration of 0.1 mol / L. After stirring for 0.5 h, a suspension A is formed. The suspension A is transferred to a polystyrene-lined reactor with a stainless steel outer reactor and reacted at 220°C for 0.5 h.

[0089] (2) After the reaction is completed and cooled to room temperature, the reactor is opened in a glove box; 9.8 mmol of lithium chloride is added to the reactor, wherein the molar ratio of vanadium chloride to lithium chloride is 1:1.4; stirring is continued for 0.5 h to obtain suspension B; 1.39 mL of hydrazine hydrate is added to suspension B, the concentration of which is 0.4 mol / L, and stirring is continued for 0.5 h to obtain precursor C;

[0090] (3) After steps (1) and (2) are carried out under oxygen-tight conditions, the polystyrene liner containing the precursor solution C is placed in the stainless steel outer kettle and a second solvothermal reaction is carried out at a temperature of 240° C. for 40 h.

[0091] (4) After the reaction is completed and cooled to room temperature, the precipitate is separated by centrifugation and washed with anhydrous ethanol; the washed product is placed in a vacuum drying oven and dried at 80°C for 12 hours; the dried sample is ground to obtain the Li3V2O5 fast-charging negative electrode material.

[0092] Example 9

[0093] (1) Weigh 14 mmol of vanadium acetylacetonate and disperse it in 70 mL of ethylene glycol at a concentration of 0.2 mol / L. After stirring for 0.5 h, a light yellow transparent solution A is formed. Solution A is transferred to a polystyrene-lined reactor with a stainless steel outer reactor and reacted at 200°C for 8 h.

[0094] (2) After the reaction is completed and cooled to room temperature, the reactor is opened in a glove box; 21.28 mmol of lithium nitrate is added to the reactor, wherein the molar ratio of vanadium acetylacetonate to lithium nitrate is 1:1.52; stirring is continued for 0.5 h to obtain suspension B; 1.49 mL of hydroxylamine hydrochloride is added to suspension B at a concentration of 0.5 mol / L, and stirring is continued for 0.5 h to obtain precursor C;

[0095] (3) After steps (1) and (2) are carried out under oxygen-tight conditions, the polystyrene liner containing the precursor solution C is placed in the stainless steel outer kettle and a second solvothermal reaction is carried out at a temperature of 220° C. for 72 h.

[0096] (4) After the reaction is completed and cooled to room temperature, the precipitate is separated by centrifugation and washed with anhydrous ethanol; the washed product is placed in a vacuum drying oven and dried at 80°C for 12 hours; the dried sample is ground to obtain the Li3V2O5 fast-charging negative electrode material.

Claims

1. A method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material, characterized in that: The following steps are involved: S1. Dispersing a vanadium source in an organic solvent to obtain a solution A having a vanadium source concentration of 0.01 mol / L-0.2 mol / L, stirring the solution A uniformly, and then performing a first solvothermal reaction at 180-240° C. for 0.5-12 h; S2. After the first solvothermal reaction is completed, a lithium source and a reducing agent are sequentially added to the resulting solution, and stirring is continued to obtain a precursor solution; The molar ratio of the vanadium source to the lithium source is (1:1.4)-(1:1.6), and the concentration of the reducing agent is 0.1-0.5 mol / L; S3, subjecting the precursor solution to a second solvothermal reaction at 200-250° C. for 12-72 h; S4. After the second solvothermal reaction is completed, the obtained product is cooled, centrifugally washed, dried, and ground to obtain a disordered rock salt Li3V2O5 fast-charging negative electrode material.

2. The method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 1, characterized in that: In step S1, the vanadium source is any one of ammonium metavanadate, vanadium chloride, vanadium acetylacetonate, and vanadium pentoxide, and the organic solvent is any one of ethanol, isopropanol, ethylene glycol, and methanol.

3. The method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 1, characterized in that: In step S2, the lithium source is any one of lithium hydroxide and its hydrate, lithium chloride, lithium nitrate, and lithium acetate, and the reducing agent is any one of hydrazine hydrate and hydroxylamine hydrochloride.

4. The method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 1, characterized in that: The molar ratio of the vanadium source to the lithium source is preferably 1:1.48-1:1.

52.

5. The method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 1, characterized in that: In step S4, the drying method is to dry the product in a vacuum drying oven at 80° C. for 12 hours.

6. The method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 1, characterized in that: Step S1 and step S2 are performed under airtight conditions to isolate oxygen.

7. The method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 1, characterized in that: The steps S1 and S2 are performed under air atmosphere, and the step S3 is to deoxygenate the precursor solution by bubbling inert gas before the second solvothermal reaction.

8. The method for preparing a disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 7, characterized in that: The inert gas is one or more of argon, nitrogen and helium.

9. A disordered rock salt Li3V2O5 fast-charging negative electrode material obtained by the preparation method according to any of claims 1-8, characterized in that: The disordered rock salt Li3V2O5 fast-charging negative electrode material has a regular block morphology and a thickness of 1 to 5 μm.

10. A lithium ion battery, characterized in that: Contains the disordered rock salt Li3V2O5 fast-charging negative electrode material according to claim 8.

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