Preparation method of organic carbon-coated positive electrode lithium supplement material

Abstract

The application provides a preparation method of an organic carbon-coated positive electrode lithium supplementing material, and comprises the following steps: S1: putting a phenolic organic material, a dispersing agent, pure water into a reaction kettle, starting heating and fast stirring to obtain A liquid; S2: slowly adding an aldehyde organic material into the A liquid and high-speed stirring to obtain an organic polymer system bottom liquid B; the application provides a bottom liquid environment of an organic phenolic resin polymerization reaction in advance, then carries out a precipitation reaction to obtain a phenolic resin-coated metal precipitate, and then carries out wet sanding mixing by first preparing a small amount of a lithium source, which can reduce the particle size of the reaction raw material, improve the material reaction activity, and achieve better mixing effect. Then, the organic carbon-coated low-lithium-coordinated LiMO precursor is prepared by the way of spray drying, and finally, the lithium-rich product is prepared by solid-phase mixing according to the final lithium-rich product, and the small-particle-size carbon-coated lithium-rich material is prepared by one-time sintering.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of lithium batteries, in particular to a preparation method of an organic carbon-coated positive electrode lithium supplementing material. BACKGROUND

[0002] During formation of a lithium ion battery, formation of an SEI film of a negative electrode consumes a large amount of active lithium, especially in the case of adding a part of a high-capacity silicon-based negative electrode material, which leads to low first-week coulomb efficiency and low battery capacity. Supplementing active lithium is an effective means to solve the problem, and there are many known ways to supplement active lithium, mainly two categories of negative electrode lithium supplementing and positive electrode lithium supplementing. The negative electrode lithium supplementing includes physical lithiumization by adding metal lithium powder to the negative electrode or roll-pressing a metal lithium foil on the surface of the electrode sheet, chemical lithiumization by using butyl lithium as a lithiumizing agent to chemically pre-embed lithium in the negative electrode, self-discharge lithiumization by contacting the negative electrode with metal lithium in an electrolyte to complete self-discharge lithiumization, and electrochemical pre-lithiation by introducing metal lithium as a third electrode in the battery, and the negative electrode and the metal lithium third electrode form a pair of electrodes to complete pre-lithiation.

[0003] The positive electrode lithium supplementing is adding a lithium-containing compound with high irreversible capacity to the positive electrode of the lithium ion battery, and according to the types of the compound, the lithium-containing compound can be divided into binary lithium-containing compounds represented by Li2O, Li2O2 and Li2S, ternary lithium-containing compounds represented by Li2NiO2, Li2SiO3, Li6CoO4 and Li5FeO4, and organic lithium-containing compounds represented by Li2DHBN and Li2C2O4.

[0004] The lithium-rich ternary lithium supplementing material represented by Li2NiO2, Li2SiO3, Li6CoO4 and Li5FeO4 generally has the characteristics of poor environmental tolerance, which is not conducive to processing of the lithium-rich material in the electrode sheet process, and even the preparation of the lithium-rich material is difficult. At present, there are still some problems in the preparation method of Li5FeO4, for example, the material particle size of the finished product is too large after multiple sintering, which causes a long lithium ion migration path and relatively low capacity, and the stability is poor.

[0005] Therefore, the application relates to a preparation method of an organic carbon-coated positive electrode lithium supplementing material. SUMMARY

[0006] Based on this, in order to solve the problems of poor conductivity and stability and high residual alkali content on the surface of the material in the background art, the application provides a preparation method of an organic carbon-coated positive electrode lithium supplementing material.

[0007] The purpose and effect of the application are achieved by the following specific technical means: a preparation method of an organic carbon-coated positive electrode lithium supplementing material, including the following steps:

[0008] S1: Phenolic organic material, dispersant, pure water, into the reaction kettle, start heating and fast stirring to get A liquid

[0009] S2: Slowly add aldehyde organic material to A liquid, and high speed stirring to get an organic polymer system bottom liquid B

[0010] S3: Add metal liquid and precipitating agent to bottom liquid B to get a phenolic resin coated precursor slurry C

[0011] S4: After the slurry C is completely aged, the filtrate is centrifuged and washed with water.

[0012] S5: Add lithium source and pure water to sand mill according to Li:M 1:1-3

[0013] S6: After sand milling, spray drying is carried out to get nanoscale carbon-coated precursor D

[0014] S7: Add lithium source and precursor D to high speed mix according to Li:M 1:2-6

[0015] S8: The uniformly mixed precursor is sintered once under inert atmosphere, and then sieved to get carbon-coated nanoscale lithium-rich material C@LiMxO.

[0016] Further preferably, in step S1, the phenolic organic material includes one or more of phenol, cresol, dimethyl phenol, o-dihydroxybenzene, m-dihydroxybenzene, p-dihydroxybenzene.

[0017] Further preferably, in step S1, the dispersant includes one or more of sodium dodecyl sulfonate, dodecyl trimethyl ammonium bromide, polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol.

[0018] Further preferably, in step S1, the heating temperature is 10-90℃.

[0019] Further preferably, in step S1, the fast stirring process is 400-1000 rpm.

[0020] Further preferably, in step S2, the slow dropwise addition speed is controlled at 0.5-5 hours.

[0021] Further preferably, in step S2, the aldehyde organic material includes one or more of formaldehyde, acetaldehyde, pentanal, hexanedial.

[0022] Further preferably, in step S2, the amount of aldehyde is 1:0.8-1 of aldehyde group: phenolic hydroxyl functional group ratio.

[0023] Further preferably, in the step S2, the high-speed stirring process is 1000-3000 rpm.

[0024] Further preferably, in the step S3, the metal liquid is one or a combination of NiSO4, CoSO4, MnSO4, Fe2(SO4)3, CuSO4, and Ti(SO4)2.

[0025] Further preferably, in the step S3, the concentration of the metal liquid is 0.5-5 mol / L.

[0026] Further preferably, in the step S3, the precipitant is one or a combination of ammonia, oxalic acid, sodium hydroxide, ammonium bicarbonate, urea, and sodium carbonate.

[0027] Further preferably, in the step S4, the aging process is performed at 20-80℃ for 2-8h.

[0028] Further preferably, in the step S4, the amount of pure water is 1:1-3, the centrifugation frequency is 40-50 HZ, and the centrifugation time is 30-120 min.

[0029] Further preferably, in the step S5, the lithium source is one or a combination of LiOH.H2O, Li2CO3, LiNO3, and Li2O.

[0030] Further preferably, in the step S5, the sand milling process is performed at a solution solid content of 10%-30%, a sand milling speed of 1500-3000 rpm, and a sand milling time of 30-120 min.

[0031] Further preferably, in the step S6, the spray drying process is performed at an inlet air temperature of 100-220℃, an inlet speed of 30-50 ml / min, and an atomization frequency of 30-50 HZ.

[0032] Further preferably, in the step S7, the high-speed mixing process is performed at a speed of 1000-2000 rpm for 30-40 min.

[0033] Further preferably, in the step S8, the inert gas is one or a combination of argon, nitrogen, helium, and neon.

[0034] Further preferably, in the step S8, the primary sintering process is performed at a sintering temperature of 400-750℃ for 10-40 h.

[0035] Further preferably, in the step S8, the screen mesh used for sieving is 200-1000 mesh.

[0036] The present application has the following advantages:

[0037] 1. The present application can reduce the particle size of the reaction raw materials and improve the reactivity of the materials by providing an organic phenolic resin polymerization reaction bottom liquid environment in advance, then performing a precipitation reaction in the bottom liquid environment to obtain a phenolic resin-coated metal precipitate, and then performing wet sanding mixing by first preparing a small amount of lithium source, on the one hand, the particle size of the reaction raw materials can be reduced to improve the reactivity of the materials, on the other hand, better mixing effect can be achieved. Then, the LiMO precursor coated with low lithium coordination and organic carbon is prepared by spray drying. Finally, the lithium-rich material coated with carbon with small particle size is prepared by solid-phase mixing according to the final lithium-rich product and then sintering.

[0038] 2. The present application can obtain a carbon-coated lithium-rich material with smaller particle size, higher carbon-coating strength and better uniformity by organic phase formation and precipitation method. BRIEF DESCRIPTION OF DRAWINGS

[0039] The present application will be further described below in conjunction with the accompanying drawings.

[0040] Figure 1 The phenolic resin-coated LiMO precursor prepared by spray drying is shown in the electron microscope image;

[0041] Figure 2 It is a schematic diagram of the first charge curve. EMBODIMENT

[0042] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the following will be combined with the accompanying drawings to further describe the present application in detail. Figures 1-2 The following examples are only examples for implementing the present application. It must be pointed out that the disclosed examples do not limit the scope of the present application. On the contrary, modifications and improvements made within the scope of the present application are also within the scope of the patent protection of the present application.

[0043] The present application prepares a lithium-rich nanomaterial coated with an organic carbon source having a core-shell structure-C@LiMxO by an organic liquid deposition method, wherein M is at least one of Ni, Co, Mn, Si, Fe, Cu and Ti, 0≤Li<8, 0

[0044] A preparation method of an organic carbon-coated positive electrode lithium supplement material.

[0045] The purposes and effects of the present application are achieved by the following specific technical means: a preparation method of an organic carbon-coated positive electrode lithium supplement material, comprising the following steps:

[0046] S1: Phenolic organic material, dispersant, pure water, into the reaction kettle, start heating and fast stirring to get A liquid

[0047] S2: Slowly add aldehyde organic material to A liquid, and high speed stirring to get an organic polymer system bottom liquid B

[0048] S3: Add metal liquid and precipitating agent to bottom liquid B to get a phenolic resin coated precursor slurry C

[0049] S4: After the slurry C is completely aged, the filtrate is centrifuged and washed with water.

[0050] S5: Add lithium source and pure water to sand mill according to Li:M ratio of 1:1-3

[0051] S6: After sand milling, spray drying is performed to obtain nano-sized carbon-coated precursor D

[0052] S7: Add lithium source and precursor D to high-speed mix according to Li:M ratio of 1:2-6

[0053] S8: The uniformly mixed precursor is sintered once under inert atmosphere, and then sieved to obtain carbon-coated nano-sized lithium-rich material C@LiMxO.

[0054] In step S1, the phenolic organic material includes one or more of phenol, cresol, dimethyl phenol, o-dihydroxybenzene, m-dihydroxybenzene, and p-dihydroxybenzene; the dispersant includes one or more of sodium dodecyl sulfonate, dodecyl trimethyl ammonium bromide, polyethylene glycol, polyvinylpyrrolidone, and polyvinyl alcohol, wherein the preferred dispersant in the system is polyethylene glycol, which can provide a good dispersion effect on metal ions.

[0055] In step S1, the heating temperature is 10-90°C, and the preferred heating temperature is 65°C. Phenol can be mixed with water in any ratio at a temperature greater than 65°C. The fast stirring process is 400-1000 rpm, and the preferred stirring is 800 rpm in order to uniformly disperse the phenolic organic material in the solution.

[0056] In step S2, the slow drop speed is controlled at 0.5-5 hours, and the preferred time is 2 hours considering the completeness of the phenolic condensation reaction. The aldehyde organic material includes one or more of formaldehyde, acetaldehyde, pentanal, and hexanedial. The amount of aldehyde is 1:0.8-1 according to the ratio of aldehyde group to phenolic hydroxyl functional group. In the alkaline environment of the later precipitation, the phenolic functional group ratio is less than 1, which can prepare thermosetting phenolic resin. The high-speed stirring process is 1000-3000 rpm.

[0057] In step S3, the metal liquid is one or a combination of NiSO4, CoSO4, MnSO4, Fe2(SO4)3, CuSO4, and Ti(SO4)2, the concentration of the metal liquid is 0.5-5 mol / L, preferably 2.0 mol / L, and the precipitant is one or a combination of ammonia, oxalic acid, sodium hydroxide, ammonium bicarbonate, urea, and sodium carbonate.

[0058] In step S4, the aging process is carried out at 20-80°C for 2-8 hours, which can make the metal ion precipitation reaction and the phenolic resin polymerization reaction more complete, the amount of pure water is 1:1-3, and the centrifugal frequency is 40-50 HZ and the centrifugal time is 30-120 min.

[0059] In step S5, the lithium source is one or a combination of LiOH.H2O, Li2CO3, LiNO3, and Li2O, preferably LiOH.H2O in terms of economy and subsequent sintering process temperature, the sanding process is that the solid content of the solution is 10%-30%, the sanding speed is 1500-3000 rpm, and the sanding time is 30-120 min.

[0060] In step S6, the spray drying process is carried out at an inlet temperature of 100-220°C, a feeding speed of 30-50 ml / min, and an atomization frequency of 30-50 HZ.

[0061] In step S7, the high-speed mixing process is carried out at a speed of 1000-2000 rpm for 30-40 min.

[0062] In step S8, the inert gas is one or a combination of argon, nitrogen, helium, and neon, preferably nitrogen in terms of safety, practicality, and economy, the primary sintering process is carried out at a sintering temperature of 400-750°C for 10-40 h, and the screen mesh used for sieving is 200-1000 mesh, preferably 300 mesh, which does not damage the organic carbon coating layer formed according to experimental verification. Embodiment

[0063] This embodiment is carried out by:

[0064] S1: phenol, polyethylene glycol, pure water, and a reaction kettle are put into the reaction kettle, heated to 65°C, and stirred at a speed of 800 rpm to obtain A liquid

[0065] S2: according to the phenol / formaldehyde ratio of 0.9:1, slowly add formaldehyde to the A liquid, control the dropping time within 2 hours, and stir at a speed of 1500 rpm to obtain an organic polymer system B

[0066] S3: Add 2.0 mol / L NiSO4 solution and ammonia water (with a ratio of Ni2+: NH4+ of 1:2) to the bottom liquid B to obtain a phenolic resin-coated precursor slurry C

[0067] S4: After the slurry C is aged at 65°C for 4 hours, the filtrate is centrifuged under the process conditions of a centrifugal frequency of 45 HZ, a washing amount of pure water of 1:2, and a centrifugal time of 45 min.

[0068] S5: Add LiOH.H2O with a ratio of Li:Ni of 1:1, and add pure water with a solid content of 15% for high-speed sanding at 2000 HZ for 60 min

[0069] S6: After sanding, spray drying is performed under the process conditions of an air inlet temperature of 220°C, a feeding speed of 30 ml / min, and an atomization frequency of 50 HZ to obtain nanoscale carbon-coated precursor C@LiNiO1.5

[0070] S7: Add lithium source with a ratio of Li:Ni of 1:1.1 to the above precursor under the process conditions of a rotation speed of 2000 rpm and a mixing time of 40 min

[0071] to obtain a material to be burned

[0072] S8: The uniformly mixed precursor is sintered at 500°C for 15 hours under a nitrogen atmosphere, and then sieved to obtain carbon-coated nanoscale lithium-rich material C@Li2NiO2

[0073] An organic C@Li2NiO2 with good coating effect is prepared, which has a discharge capacity of 426 mAh / g, an alcohol-phase surface residual alkali of 1300 ppm, and a dew point hygroscopic value of 95 ppm / s EMBODIMENT

[0074] This embodiment is prepared by:

[0075] S1: Put hydroquinone, polyvinylpyrrolidone, and pure water into a reaction kettle, heat to 70°C, and stir at 800 rpm to obtain liquid A

[0076] S2: Slowly add formaldehyde to liquid A with a phenolic ratio of 0.95:1, control the dropping time within 2 hours, and stir at 1500 rpm to obtain an organic polymer system bottom liquid B

[0077] S3: Add 2.0 mol / L Fe2(SO4)3 solution and sodium hydroxide (with a ratio of Fe3+: OH- of 1:3) to the bottom liquid B to obtain a phenolic resin-coated precursor slurry C

[0078] S4: After slurry C is aged at 80℃ for 4 hours, the filtrate is centrifuged under the process conditions of a centrifugal frequency of 45HZ, a washing amount of pure water of 1:3, and a centrifugal time of 60min.

[0079] S5: LiOH.H2O is added at a ratio of Li:Fe of 1:1.05, and pure water is added at a solid content of 20% for high-speed sanding at 2000HZ for 45min

[0080] S6: After sanding, the precursor C@LiFeO2 is obtained by spray drying under the process conditions of an air inlet temperature of 220℃, a feeding speed of 45ml / min, and an atomization frequency of 50HZ

[0081] S7: The lithium source and the precursor are mixed at a rotation speed of 2000rpm for 40min under the process conditions of a ratio of Li:Fe of 1:4.05

[0082] to obtain the material to be burned

[0083] S8: The uniformly mixed precursor is sintered at 450℃ for 30 hours under a nitrogen atmosphere, and then sieved to obtain the carbon-coated nanoscale lithium-rich material C@Li5FeO4

[0084] An organic C@Li5FeO4 with good coating effect is prepared, which has a discharge capacity of 715mAh / g, an alcohol phase surface residual alkali of 1950ppm, and a dew point hygroscopic value of 125ppm / s EMBODIMENT

[0085] This embodiment is prepared by:

[0086] S1: Resorcinol, dodecyltrimethylammonium bromide, pure water, and a reaction kettle are put into the reaction kettle, heated to 70℃, and stirred at 800rpm to obtain liquid A

[0087] S2: Formaldehyde is slowly added to liquid A at a phenol / formaldehyde ratio of 0.90:1, and the dropping is completed within 2 hours, and high-speed stirring is performed at 1500rpm to obtain an organic polymer system bottom liquid B

[0088] S3: A CoSO4 solution of 2.0mol / L and sodium hydroxide are added to the bottom liquid B at a ratio of Co2++:OH- of 1:2 to obtain a phenol formaldehyde resin-coated precursor slurry C

[0089] S4: After slurry C is aged at 80℃ for 4 hours, the filtrate is centrifuged under the process conditions of a centrifugal frequency of 45HZ, a washing amount of pure water of 1:2, and a centrifugal time of 60min.

[0090] S5: LiOH.H2O was added according to Li:Co of 1:1.1, and pure water was added according to a solid content of 20% to perform 2000HZ high-speed sanding for 45min

[0091] S6: After sanding, the precursor C@LiCoO2 was obtained by spray drying under the process conditions of an air inlet temperature of 200℃, a feeding speed of 45ml / min, and an atomization frequency of 50HZ

[0092] S7: LiOH was added according to Li:Co of 1:5.05, and the precursor was mixed at a rotation speed of 2000rpm for 40min to obtain a material to be sintered

[0093] S8: The mixed precursor was sintered at 550℃ for 25 hours under a nitrogen atmosphere, and then sieved to obtain the carbon-coated nanoscale lithium-rich material C@Li6CoO4

[0094] An organic C@Li6CoO4 with good coating effect was prepared, the discharge capacity reached 765mAh / g, the residual alkali on the alcohol surface was reduced to 2530ppm, and the dew point hygroscopic value was reduced to 145ppm / s Embodiment

[0095] In this embodiment:

[0096] S1: Hydroquinone, sodium dodecyl sulfate, pure water, and a reaction kettle were put into the reaction kettle, heated to 75℃, and stirred at 800rpm to obtain liquid A

[0097] S2: Formaldehyde was slowly added to liquid A according to a phenol / formaldehyde ratio of 0.96:1, the dropping was completed within 2 hours, and high-speed stirring was performed at 1500rpm to obtain an organic polymer system bottom liquid B

[0098] S3: A 1.5mol / L MnSO4 solution and sodium hydroxide were added to the bottom liquid B, and Mn2+:OH- was 1:2 to obtain a phenol formaldehyde resin coated precursor slurry C

[0099] S4: After the slurry C was aged at 80℃ for 4 hours, the filtrate was centrifuged according to a centrifugation frequency of 45HZ, pure water was added according to a washing amount of 1:4, and the process conditions of a centrifugation time of 30min were used for centrifugal washing.

[0100] S5: LiOH.H2O was added according to Li:Mn of 1:1.15, and pure water was added according to a solid content of 25% to perform 2000HZ high-speed sanding for 45min

[0101] S6: After sanding, spray drying was carried out under the process conditions of an air inlet temperature of 200℃, a feeding speed of 45ml / min, and an atomization frequency of 50HZ to obtain a nano-sized carbon-coated precursor C@LiMnO2

[0102] S7: High-speed mixing was carried out under the process conditions of a rotation speed of 2000rpm and a mixing time of 40min by adding lithium oxide to the above precursor at a ratio of Li:Mn of 1:5.1 to obtain a material to be sintered

[0103] S8: The uniformly mixed precursor was sintered at 650℃ for 30 hours under a nitrogen atmosphere, and then sieved to obtain a carbon-coated nano-sized lithium-rich material C@Li6MnO4

[0104] An organic C@Li6MnO4 with good coating effect was prepared, the discharge capacity reached 748mAh / g, the residual alkali on the alcohol phase surface was reduced to 2680ppm, and the dew point hygroscopic value was reduced to 148ppm / s

[0105] Comparative Example 1

[0106] In this comparative example, a C@Li2NiO2 was obtained by ball-milling, mixing, adding a conductive carbon source Super-P, lithium oxide, and nickel hydroxide, sintering under a nitrogen atmosphere, and then crushing. The discharge capacity was only 365mAh / g, the residual alkali on the alcohol phase surface was 5800ppm, and the dew point hygroscopic value was 435ppm / s

[0107] Comparative Example 2

[0108] In this comparative example, a C@Li5FeO4 was obtained by ball-milling, mixing, adding a conductive carbon source Super-P, lithium hydroxide, and iron oxide, sintering under a nitrogen atmosphere, and then crushing. The discharge capacity was 550mAh / g, the residual alkali on the alcohol phase surface was 13650ppm, and the dew point hygroscopic value was 1650ppm / s

[0109] Comparative Example 3

[0110] In this comparative example, a C@Li6CoO4 was obtained by ball-milling, mixing, adding a conductive carbon source Super-P, lithium oxide, and Co3O4, sintering under a nitrogen atmosphere, and then crushing. The discharge capacity was 585mAh / g, the residual alkali on the alcohol phase surface was 16530ppm, and the dew point hygroscopic value was 1865ppm / s

[0111] Comparative Example 4

[0112] The comparative example is obtained by ball-milling mixing of a conductive carbon source Super-P, lithium oxide and MnO2, mixing uniformly, sintering in a nitrogen atmosphere, and then crushing to obtain a C@Li6MnO4, which has a discharge capacity of 573 mAh / g, an alcohol-phase surface residual alkali test value of 18563 ppm, and a dew point moisture absorption value of 1765 ppm / s

[0113] As can be seen from the overall performance comparison between the comparative example and the examples in the following table, the moisture absorption value and the alcohol-phase surface residual alkali of the material after coating with an organic carbon film are significantly reduced, that is, coating with an organic carbon film can effectively prevent the lithium-rich material from contacting with moisture in the air and thus decomposing residual alkali, so that the stability of the lithium-rich material is greatly improved, and the discharge capacity of the lithium-rich material is also improved to a certain extent.

[0114] Group Capacity (mAh / g) Moisture pick-up value at dew point -20°C (ppm / S) Alcohol phase surface residual base ppm Comparative Example 1 365 435 5800 Example 1 426 95 1300 Comparative Example 2 550 1650 13650 Example 2 715 125 1950 Comparative Example 3 585 1865 16530 Example 3 765 145 2530 Comparative Example 4 573 1765 18563 Example 4 748 148 2680

Claims

1. A method for preparing an organic carbon-coated positive electrode lithium replenishment material, characterized in that, Includes the following steps: S1: Add phenolic organic materials, dispersant, and pure water into a reaction vessel, turn on the heating and stir rapidly to obtain solution A; S2: Slowly add aldehyde organic material dropwise to liquid A and stir at high speed to obtain a bottom liquid B of an organic polymerization system; S3: Adding molten metal and a precipitant to the base liquid B will yield a phenolic resin-coated precursor slurry C; S4: After the slurry C has fully aged, the filtrate is centrifuged and washed with water. S5: Add lithium source and pure water at a Li:M ratio of 1:1-3 and perform sand milling; S6: After sand milling, spray drying is performed to obtain nano-scale carbon-coated precursor D; S7: Add lithium source and precursor D at a Li:M ratio of 1:2-6 and mix at high speed; S8: The above-mentioned uniformly mixed precursor is sintered once under an inert atmosphere and then sieved to obtain carbon-coated nanoscale lithium-rich material C@LiMxO; In step S2, the amount of aldehydes used is based on a ratio of aldehyde group to phenolic hydroxyl functional group of 1:0.8-1. In step S2, the dripping speed is controlled to be completed within 0.5-5 hours; Where M is at least one of the elements Ni, Co, Mn, Si, Fe, Cu, and Ti, and the number of atoms is 0. <Li<8,0<x<5,0<O<6。 2. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S1, the phenolic organic materials include one or more of the following: phenol, cresol, xylenol, catechol, resorcinol, and hydroquinone.

3. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S1, the dispersant includes one or more of the following materials: sodium dodecyl sulfonate, dodecyltrimethylammonium bromide, polyethylene glycol, polyvinylpyrrolidone, and polyvinyl alcohol.

4. The method for preparing an organic carbon-coated cathode lithium replenishment material according to claim 1, characterized in that: In step S1, the heating temperature is between 10-90℃.

5. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S1, the rapid stirring process is 400-1000 rpm.

6. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S2, the aldehyde organic materials include one or more of formaldehyde, acetaldehyde, pentanal, and adipaldehyde.

7. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S2, the high-speed stirring process is 1000-3000 rpm.

8. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S3, the molten metal is one or more of the following materials: NiSO4, CoSO4, MnSO4, Fe2(SO4)3, CuSO4, and Ti(SO4)2.

9. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S3, the concentration of the liquid metal is 0.5-5 mol / L.

10. The method for preparing an organic carbon-coated cathode lithium replenishment material according to claim 1, characterized in that: In step S3, the precipitant is one or a combination of ammonia, oxalic acid, sodium hydroxide, ammonium bicarbonate, urea, and sodium carbonate.

11. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S4, the aging process conditions are 20-80℃ and the aging time is 2-8h.

12. The method for preparing an organic carbon-coated cathode lithium replenishment material according to claim 1, characterized in that: In step S4, the pure water volume is 1:1-3, the centrifugation frequency is 40-50Hz, and the centrifugation time is 30-120min.

13. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S5, the lithium source is one or a combination of materials such as LiOH·H2O, Li2CO3, LiNO3, and Li2O.

14. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S5, the sand milling process involves a solution solid content of 10%-30%, a sand milling speed of 1500-3000 rpm, and a sand milling time of 30-120 min.

15. The method for preparing an organic carbon-coated cathode lithium replenishment material according to claim 1, characterized in that: In step S6, the spray drying process conditions are: inlet air temperature 100-220℃, feed rate 30-50ml / min, and atomization frequency 30-50Hz.

16. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S7, the high-speed mixing process involves a rotation speed of 1000-2000 rpm and a mixing time of 30-40 min.

17. The method for preparing an organic carbon-coated cathode lithium replenishment material according to claim 1, characterized in that: In step S8, the inert gas is one or a combination of argon, nitrogen, helium, and neon.

18. The method for preparing an organic carbon-coated cathode lithium replenishment material according to claim 1, characterized in that: In step S8, the sintering process is carried out at a sintering temperature of 400-750℃ and a sintering time of 10-40h.

19. The method for preparing an organic carbon-coated positive electrode lithium replenishment material according to claim 1, characterized in that: In step S8, the sieve used for sieving has a mesh size of 200-1000.

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