A positive electrode precursor, a preparation method thereof, a positive electrode material, and a battery

Abstract

The application provides a positive electrode precursor, a preparation method of the positive electrode precursor, a positive electrode material and a battery. x Co y M 1‑x‑y R z , wherein 0<=x<=1, 0<=y<=1, 1<=z<=2, M comprises Mn and / or Al, and R comprises hydroxyl ions and / or carbonate ions. The precursor material provided by the application realizes that the internal primary particles are distributed in a radial direction, stress can be quickly released, and the volume change during charging and discharging is effectively alleviated; the particle surface morphology is also ensured to be compact, and the corrosion by an electrolyte is effectively prevented; and therefore, the cycle, capacity and power are considered.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of battery materials, and relates to a positive electrode precursor, a preparation method thereof, a positive electrode material and a battery, in particular to a positive electrode precursor, a preparation method thereof, a positive electrode material and a battery which can be used in lithium ion batteries and sodium ion batteries. BACKGROUND

[0002] With the development of electric vehicles, the market gradually puts forward higher requirements for the large-current charge and discharge capacity and long cycle life capacity of batteries. The performance of the battery mainly depends on the positive electrode material, and the performance of the positive electrode material is strongly related to the precursor. Therefore, improving the physical and chemical properties and morphology of the precursor is the most convenient way to optimize the power battery.

[0003] Generally speaking, in the case of large-current charge and discharge and long-term high-temperature cycle, irreversible damage will be caused to the battery material, mainly due to the collapse of the structure of the positive electrode material under the above working conditions.

[0004] Surface coating is the most convenient and effective solution, but there are some problems: (1) due to the lattice difference between the coating material and the bulk material, the coating material is easy to fall off; (2) the coating material is generally implemented through a lithium-doped calcination step, and the uniformity of the coating layer is difficult to accurately control. And although the coating can solve the problem of cycle life, it will cause the side effects of power performance and capacity decline.

[0005] For example, CN112758992A discloses a production method of a multi-layer coated cobalt-free precursor: comprising the following steps: S1, dissolving nickel salt, dissolving manganese salt into a nickel-manganese inorganic salt mixture; dissolving magnesium salt, dissolving aluminum salt into a magnesium-aluminum inorganic salt mixture; S2, preparing an ammonia solution and a sodium hydroxide solution; S3, first performing a co-precipitation reaction with the nickel-manganese inorganic salt mixture, the ammonia solution and the sodium hydroxide solution; thereafter, every time the particle size increases by 0.5-1.5 μm, the nickel-manganese inorganic salt mixture and the magnesium-aluminum inorganic salt mixture are switched to be introduced, until the product reaches the required particle size; S4, placing the obtained slurry into an aging tank, aging for 2-20 h, and then filtering, washing, drying and sieving in sequence, to obtain a multi-layer coated cobalt-free precursor.

[0006] For example, CN108134064A discloses a positive electrode material precursor, a preparation method thereof and a positive electrode material. The present application coats flocculent Mn3O4 with better dispersibility and less agglomeration on Ni 1-x-y Co x Mn yThe B element and the F element are doped in the base material, the B element is gradually reduced from inside to outside, the F element is gradually increased from inside to outside, the positive electrode material precursor is coated more uniformly, and the positive electrode material for lithium ion batteries with better thermal stability and electrochemical performance is obtained by mixing and calcining the positive electrode material precursor with a lithium-containing compound.

[0007] Therefore, how to improve the structural stability of the positive electrode material, and balance the cycle performance, capacity and power, is a technical problem to be solved. SUMMARY

[0008] In view of the problems in the prior art, the purpose of the present application is to provide a positive electrode precursor and a preparation method thereof, a positive electrode material and a battery. The B doping amount of the precursor material provided by the present application gradually decreases from inside to outside, realizes the radial distribution of the internal primary particles, can quickly release stress, and effectively alleviates the volume change during charging and discharging. At the same time, the F doping amount gradually increases from inside to outside, ensures the dense surface morphology of the particles, and effectively prevents corrosion by the electrolyte. Therefore, the structural stability of the positive electrode material is improved, and the balance of cycle, capacity and power is realized.

[0009] To achieve the purpose of the present application, the following technical solutions are adopted:

[0010] In a first aspect, the present application provides a positive electrode precursor material, which comprises a base material and B elements and F elements doped in the base material.

[0011] The doping amount of the B element gradually decreases from inside to outside in the base material, and the doping amount of the F element gradually increases from inside to outside in the base material.

[0012] The chemical formula of the base material is Ni x Co y M 1-x-y R z , wherein 0≤x≤1, 0≤y≤1, 1≤z≤2, M includes Mn and / or Al, and R includes hydroxyl ions and / or carbonate ions.

[0013] For example, the x can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1, etc., the y can be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1, etc., and the z can be 1, 1.5 or 2, etc.

[0014] The precursor material provided by the present application can be a carbonate system or a hydroxide system, and the specific stoichiometric ratio can be adjusted according to actual needs.

[0015] The precursor material provided by the application has gradually reduced doping amount of B from inside to outside, realizes radial distribution of internal primary particles, can quickly release stress, and effectively alleviates volume change during charging and discharging; meanwhile, the doping amount of F gradually increases from inside to outside, guarantees compact surface morphology of the particles, and effectively prevents corrosion by electrolyte; thereby, structural stability of the positive electrode material is improved, and cycle, capacity and power are balanced.

[0016] That is, the application realizes internal adjustment of arrangement of primary particles, increases corrosion resistance of the particle surface, and reduces side effects caused by doping elements through the synergistic cooperation of gradient doping of B and F; if only one kind of element is doped, such as only B is doped and gradient doping is performed, a large amount of lithium-nickel mixing is caused, which leads to capacity reduction; if only F is doped and gradient doping is performed, cycle performance is poor, and the particles are prone to cracking; if B and F are doped at the same time but gradient doping is not performed, the doping amount is too large, which leads to overall specific capacity reduction.

[0017] Preferably, the D50 of the positive electrode precursor material is 5-20 μm, for example, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, etc.

[0018] Preferably, the base material further comprises a doping cation.

[0019] In the application, other elements can also be doped, which are conventional technical choices, including but not limited to W, Zr, Al, Ti or La, etc., and can be single doping or doping of multiple elements, which can be adaptively selected according to actual needs; meanwhile, the doping amount of B and F in the application is also controlled according to actual needs, which guarantees the rule of gradient distribution.

[0020] In a second aspect, the application provides a preparation method of the positive electrode precursor material according to the first aspect, and the preparation method comprises the following steps:

[0021] The main metal element salt solution, the precipitant solution, the complexing agent solution, the fluorine-containing solution and the boron-containing solution are added into the bottom liquid in parallel to perform a co-precipitation reaction, and the flow rate of the fluorine-containing solution is gradually increased and the flow rate of the boron-containing solution is gradually reduced during the co-precipitation reaction process;

[0022] The main metal element in the main metal element salt solution is consistent with the metal element in Ni x Co y M 1-x-y R z .

[0023] The preparation method provided by the application can obtain a gradient-doped precursor material by regulating the flow of the fluorine-containing solution (fluoride ion) and the boron-containing solution (borate ion) in the co-precipitation process, thereby ensuring that the doping amount of B gradually decreases from inside to outside and the doping amount of F gradually increases, stabilizing the material structure, and the preparation process is simple and easy to operate, and is suitable for large-scale production.

[0024] Preferably, the main metal element salt solution comprises any one or a combination of at least two of a main element sulfate solution, a main element nitrate solution or a main element chloride solution.

[0025] Preferably, the main metal element salt solution further comprises a doping ion.

[0026] Preferably, the concentration of the main metal salt solution is 80-120 g / L, for example, 80 g / L, 90 g / L, 100 g / L, 110 g / L or 120 g / L, etc.

[0027] Preferably, the precipitant solution comprises any one or a combination of at least two of a sodium hydroxide solution, a sodium carbonate solution or an ammonium bicarbonate solution.

[0028] Preferably, the concentration of the precipitant solution is 200-400 g / L, for example, 200 g / L, 250 g / L, 300 g / L, 350 g / L or 400 g / L, etc.

[0029] Preferably, the complexing agent solution comprises any one or a combination of at least two of an ammonia solution, an oxalic acid solution or a citric acid solution.

[0030] Preferably, the mass fraction of the complexing agent solution is 10-20%, for example, 10%, 15% or 20%, etc.

[0031] Preferably, the fluorine-containing solution comprises any one or a combination of at least two of a sodium fluoride solution, an ammonium fluoride solution or an ammonium hydrogen fluoride solution.

[0032] Preferably, the concentration of fluoride ions in the fluorine-containing solution is 0.5-2 g / L, for example, 0.5 g / L, 0.8 g / L, 1 g / L, 1.3 g / L, 1.5 g / L, 1.8 g / L or 2 g / L, etc.

[0033] In the application, the concentration of fluoride ions in the fluorine-containing solution is 0.5-2 g / L, which can better regulate the doping amount, and too low will cause the doping amount to be too large, affecting the pH of the system, and too high will cause uneven doping and inaccurate doping amount.

[0034] Preferably, the boron-containing solution comprises any one or a combination of at least two of a sodium metaborate solution, an ammonium metaborate solution or a boric acid solution.

[0035] Preferably, the concentration of borate ions in the boron-containing solution is 0.5-2 g / L, for example 0.5 g / L, 0.8 g / L, 1 g / L, 1.3 g / L, 1.5 g / L, 1.8 g / L or 2 g / L, etc.

[0036] In the present application, the concentration of borate ions in the boron-containing solution is 0.5-2 g / L, which can better regulate the doping amount. Too low a concentration will result in too large a doping amount, affecting the pH of the system, while too high a concentration will result in uneven doping and inaccurate doping amount.

[0037] Preferably, the initial flow rate of the fluorine-containing solution is 0.8-2 L / h, for example 0.8 L / h, 0.9 L / h, 1 L / h, 1.1 L / h, 1.2 L / h, 1.3 L / h, 1.4 L / h, 1.5 L / h, 1.6 L / h, 1.7 L / h, 1.8 L / h, 1.9 L / h or 2 L / h, etc.

[0038] Preferably, the initial flow rate of the boron-containing solution is 0.1-1 L / h, for example 0.1 L / h, 0.2 L / h, 0.3 L / h, 0.4 L / h, 0.5 L / h, 0.6 L / h, 0.7 L / h, 0.8 L / h, 0.9 L / h or 1 L / h, etc.

[0039] In the present application, if the initial flow rate of the fluorine-containing solution is too high, the overall F doping amount will be too high, while if the initial flow rate of the boron-containing solution is too low, it will be difficult to control the morphology.

[0040] In the present application, the increase rate of the flow rate of the fluorine-containing solution and the decrease rate of the flow rate of the boron-containing solution can be adjusted adaptively according to the doping amount and the target particle size.

[0041] Preferably, the reaction temperature of the co-precipitation reaction is 40-60℃, for example 40℃, 45℃, 50℃, 55℃ or 60℃, etc.

[0042] Preferably, the pH value of the co-precipitation reaction is 8-12, for example 8, 8.3, 8.5, 8.8, 9, 9.3, 9.5, 9.8, 10, 10.3, 10.5, 10.8, 11, 11.3, 11.5, 11.8 or 12, etc.

[0043] Preferably, aging is performed after the co-precipitation reaction.

[0044] Preferably, the aging time is 2-18 h, for example 2 h, 5 h, 10 h, 15 h or 18 h, etc.

[0045] As a preferred technical solution, the preparation method comprises the following steps:

[0046] The main metal element salt solution, the precipitant solution, the complexing agent solution, the fluoride ion concentration of 0.5-2 g / L fluoride-containing solution and the borate ion concentration of 0.5-2 g / L boron-containing solution are added into the bottom liquid in parallel in the environment with the pH value of 8-12, and the co-precipitation reaction is carried out, in the co-precipitation reaction process, the initial flow of the fluoride-containing solution is 0.1-1 L / h and the flow gradually increases, and the initial flow of the boron-containing solution is 0.8-2 L / h and the flow gradually decreases;

[0047] The metal element in the main metal element salt solution is consistent with the metal element in the main metal element of the lithium ion positive electrode material. x Co y M 1-x-y R z The metal element in the main metal element salt solution is consistent with the metal element in the main metal element of the lithium ion positive electrode material.

[0048] In a third aspect, the application provides a positive electrode material, which is obtained by mixing and sintering the positive electrode precursor of the first aspect with a lithium salt or a sodium source.

[0049] In the application, the precursor material can be used to prepare a lithium ion positive electrode material or a sodium ion positive electrode material.

[0050] When the lithium ion positive electrode material is prepared, the positive electrode precursor is mixed and sintered with a lithium source, and the specific preparation process and parameter setting are conventional technical means.

[0051] When the sodium ion positive electrode material is prepared, the positive electrode precursor is mixed and sintered with a sodium source, and the specific preparation process and parameter setting are conventional technical means.

[0052] In a fourth aspect, the application further provides a battery, which comprises the positive electrode material of the third aspect.

[0053] Preferably, the battery comprises a lithium ion battery and / or a sodium ion battery.

[0054] Compared with the prior art, the application has the following beneficial effects:

[0055] (1) The doping amount of B in the precursor material provided by the application gradually decreases from inside to outside, realizes the radial distribution of the internal primary particles, can quickly release stress, and effectively alleviates the volume change during charging and discharging; at the same time, the doping amount of F gradually increases from inside to outside, ensures the compact surface morphology of the particles, and effectively prevents corrosion by the electrolyte; thereby improving the structural stability of the positive electrode material, and realizing the balance of cycle, capacity and power.

[0056] (2) The preparation method provided by the application can obtain gradient-doped precursor materials by regulating the flow of the fluorine-containing solution (fluoride ions) and the boron-containing solution (borate ions) in the co-precipitation process, thereby ensuring that the B doping amount gradually decreases from the inside to the outside, and the F doping amount gradually increases, stabilizing the material structure, and the preparation process is simple and easy to operate, and is suitable for large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 The SEM image of the positive electrode precursor provided for Example 1. DETAILED DESCRIPTION

[0058] The technical solutions of the application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the application, and should not be regarded as specific limitations on the application.

[0059] Example 1

[0060] The positive electrode precursor material provided in this embodiment includes a nickel-cobalt-manganese hydroxide base material and B elements, F elements, Zr elements and Al elements doped in the base material.

[0061] The doping amount of the B elements decreases from the inside to the outside in the base material, and the doping amount of the F elements increases from the inside to the outside in the base material.

[0062] The preparation method of the positive electrode precursor material is as follows:

[0063] Step 1, prepare a mixed solution A containing nickel ions, cobalt ions, manganese ions, zirconium ions and aluminum ions (the molar ratio of nickel, cobalt, manganese, zirconium and aluminum is 6:1:3:0.1:0.1), configure a precipitant solution B, a complexing agent solution C, a B ion-containing solution D and an F ion-containing solution E;

[0064] The total metal ion concentration of the mixed solution A is 80 g / L, the precipitant is a sodium hydroxide solution with a concentration of 200 g / L, the complexing agent is ammonia water with a mass fraction of 20%, the solution D is a sodium metaborate solution with a borate ion concentration of 2 g / L, and the solution E is a sodium fluoride solution with an F ion concentration of 2 g / L;

[0065] Step 2, control the reaction kettle at 48℃, and add the precipitant solution and the complexing agent solution as the bottom liquid in the reaction kettle, and the bottom liquid accounts for 1 / 2 of the volume of the entire reaction kettle;

[0066] Step 3, add the mixed solution A, the precipitant solution B, the complexing agent solution C, the solution D and the solution E into the reaction kettle in parallel flow, and continuously stir; according to the growth particle size (10 μm), adjust the flow of the solution D and the solution E.

[0067] Solution D has an initial flow rate of 2 L / h, and gradually decreases to 0.1 L / h at a certain rate (0.05 L / h per hour) through a control program as the reaction proceeds, and solution E has an initial flow rate of 0.1 L / h, and gradually increases to 2 L / h at a certain rate (0.05 L / h per hour) through a control program as the reaction proceeds.

[0068] After the reaction in step 4 is completed, the reaction slurry is placed in an aging tank for aging for 10 h, and then is sequentially filtered, washed, dried, and sieved to obtain the positive electrode precursor material.

[0069] Figure 1 An SEM image of the positive electrode precursor provided in Example 1 is shown, from which it can be seen that the internal part is arranged in a radial manner, and the surface layer is compact, which can effectively improve the stability of the material. Figure 1 An SEM image of the positive electrode precursor provided in Example 1 is shown, from which it can be seen that the internal part is arranged in a radial manner, and the surface layer is compact, which can effectively improve the stability of the material.

[0070] Example 2

[0071] The difference between this example and Example 1 is that, in this example, the initial flow rate of the sodium metaborate solution in step 3 is 0.8 L / h, and the initial flow rate of the ammonium fluoride solution is 1 L / h.

[0072] The remaining preparation methods and parameters are consistent with those in Example 1.

[0073] Example 3

[0074] The difference between this example and Example 1 is that, in this example, step 1 is to prepare a mixed solution A containing nickel ions, manganese ions, zirconium ions and aluminum ions (the molar ratio of nickel, manganese, zirconium and aluminum is 7:3:0.1:0.1), the initial flow rate of the sodium metaborate solution in step 3 is 1.5 L / h, and the initial flow rate of the ammonium fluoride solution is 0.5 L / h.

[0075] Example 4

[0076] The difference between this example and Example 1 is that, in this example, the precipitant solution is a sodium carbonate solution.

[0077] The remaining preparation methods and parameters are consistent with those in Example 1.

[0078] Example 5

[0079] The difference between this example and Example 1 is that, in this example, the initial flow rate of the sodium metaborate solution in step 4 is 0.5 L / h; wherein the doping amount of boron is changed according to the flow rate control.

[0080] The remaining preparation methods and parameters are consistent with those in Example 1.

[0081] Example 6

[0082] The difference between the present example and Example 1 is that the initial flow rate of the ammonium fluoride solution in Step 4 of the present example is 1.5 L / h; wherein the doping amount of fluorine is changed according to the regulation of the flow rate.

[0083] The remaining preparation methods and parameters remain the same as those of Example 1.

[0084] Comparative Example 1

[0085] The difference between the present example and Example 1 is that the positive electrode precursor provided in the present comparative example is not doped with fluorine.

[0086] The preparation method does not contain an ammonium fluoride solution.

[0087] The remaining preparation methods and parameters remain the same as those of Example 1.

[0088] Comparative Example 2

[0089] The difference between the present example and Example 1 is that the positive electrode precursor provided in the present comparative example is not doped with boron.

[0090] The preparation method does not contain a sodium metaborate solution.

[0091] The remaining preparation methods and parameters remain the same as those of Example 1.

[0092] Comparative Example 3

[0093] The difference between the present example and Example 1 is that B and F are not gradient-doped in the present comparative example, but are uniformly distributed in the base material.

[0094] In the preparation method, the ammonium fluoride solution is reacted at a fixed flow rate of 1 L / h, and the sodium metaborate solution is reacted at a fixed flow rate of 1 L / h.

[0095] The remaining preparation methods and parameters remain the same as those of Example 1.

[0096] The positive electrode precursor materials provided in Examples 1-6 and Comparative Examples 1-3 are mixed with lithium hydroxide at a molar ratio of Li:M (M is a metal element) = 1.05, and calcined at a temperature of 800°C for 13 h in an air atmosphere to obtain positive electrode materials.

[0097] The positive electrode materials provided in Examples 1-6 and Comparative Examples 1-3 are used as positive electrode active substances, and the positive electrode active substance: PVDF: SP is at a mass ratio of 75 / 15 / 10, NMP is added to obtain a positive electrode slurry, which is coated onto the surface of an aluminum foil to obtain a positive electrode sheet with a compaction density of 3.4 g / cm 3 and a single-sided coating surface density of 13 mg / cm 2 .

[0098] A coin cell is assembled by using a lithium sheet as a counter electrode and the positive electrode sheet.

[0099] Electrochemical performance tests were conducted on the coin cells provided in Examples 1-6 and Comparative Examples 1-3. The test conditions were as follows: electrochemical window: 2.5-4.3V, 100 cycles at 0.2C / 0.5C, and 50 cycles at 0.2C / 1C. The test results are shown in Table 1.

[0100] Table 1

[0101] Cycling retention (%) Rate retention (%) Example 1 95 91 Example 2 94 91 Example 3 94 90 Example 4 93 91 Example 5 90 87 Example 6 90 85 Comparative Example 1 85 85 Comparative Example 2 87 82 Comparative Example 3 87 84

[0102] As can be seen from the data results of Examples 1-4, the main metal element in the precursor material provided by the present invention can be either a binary material or a ternary material, both of which can achieve a balance between cycle life, capacity and power performance.

[0103] The data from Examples 1 and 5-6 show that if the initial flow rate of the boron-containing solution is too low, poor circulation performance will occur during the subsequent decreasing process; while if the initial flow rate of the fluorine-containing solution is too high, the overall energy density will be affected during the subsequent increasing process.

[0104] As can be seen from the data results of Example 1 and Comparative Examples 1-3, in the precursor material provided by the present invention, the gradient increase of fluorine and the gradient decrease of B are indispensable. Without any element, or without gradient doping, it is impossible to improve the rate performance of the material while maintaining the cycle life.

[0105] In summary, the precursor material provided by this invention has a gradually decreasing amount of B doping from the inside out, resulting in a radial distribution of the internal primary particles. This allows for rapid stress release and effectively mitigates volume changes during charging and discharging. Simultaneously, the gradually increasing amount of F doping from the inside out ensures a dense particle surface morphology, effectively preventing corrosion by the electrolyte. This enhances the structural stability of the cathode material and achieves a balance between cycle life, capacity, and power.

[0106] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A positive electrode precursor material, characterized by, The positive electrode precursor material comprises a base material and B and F elements doped in the base material; The doping amount of the B element decreases from inside to outside in the base material, and the doping amount of the F element increases from inside to outside in the base material; The chemical general formula of the base material includes Ni x Co y M 1-x-y R z , wherein 0 < x ≤ 1, 0 < y ≤ 1, 1 ≤ z ≤ 2, M includes Mn and / or Al, and R includes hydroxyl ions and / or carbonate ions. The positive electrode precursor material is prepared by a preparation method comprising the following steps: The main metal element salt solution, the precipitant solution, the complexing agent solution, the fluorine-containing solution and the boron-containing solution are added into the bottom liquid in parallel to perform a co-precipitation reaction, and during the co-precipitation reaction, the flow rate of the fluorine-containing solution gradually increases, and the flow rate of the boron-containing solution gradually decreases; wherein the main metal element in the main metal element salt solution and Ni x Co y M 1-x-y R z the metal element in the metal element salt solution are consistent.

2. The positive electrode precursor material of claim 1, wherein, The D50 of the positive electrode precursor material is 5-20 μm.

3. The positive electrode precursor material of claim 1, wherein, The base material further comprises a doping cation.

4. A method of producing the positive electrode precursor material according to any one of claims 1 to 3, characterized by, The preparation method comprises the following steps: The main metal element salt solution, the precipitant solution, the complexing agent solution, the fluorine-containing solution and the boron-containing solution are added into the bottom liquid in parallel to perform a co-precipitation reaction, and during the co-precipitation reaction, the flow rate of the fluorine-containing solution gradually increases, and the flow rate of the boron-containing solution gradually decreases; wherein the main metal element in the main metal element salt solution and Ni x Co y M 1-x-y R z the metal element in the metal element salt solution is consistent.

5. The method of claim 4, wherein the method further comprises: The main metal element salt solution further comprises a doping ion.

6. The method of claim 4, wherein the method further comprises: The concentration of the main metal element salt solution is 80-120 g / L.

7. The method of claim 4, wherein the method further comprises: The precipitant solution comprises any one or a combination of at least two of a sodium hydroxide solution, a sodium carbonate solution or an ammonium bicarbonate solution.

8. The method of claim 4, wherein the method further comprises: The concentration of the precipitant solution is 200-400 g / L.

9. The method of claim 4, wherein the method further comprises, The complexing agent solution comprises any one or a combination of at least two of an ammonia solution, an oxalic acid solution or a citric acid solution.

10. The method of claim 4, wherein the method further comprises: The mass fraction of the complexing agent solution is 10-20%.

11. The method of claim 4, wherein the method further comprises, The fluorine-containing solution comprises any one or a combination of at least two of a sodium fluoride solution, an ammonium fluoride solution or an ammonium hydrogen fluoride solution.

12. The method of claim 4, wherein the method further comprises: The concentration of the fluorine ion in the fluorine-containing solution is 0.5-2 g / L.

13. The method of claim 4, wherein the method further comprises: The boron-containing solution comprises any one or a combination of at least two of a sodium metaborate solution, an ammonium metaborate solution or a boric acid solution.

14. The method of claim 4, wherein the method further comprises: The concentration of the borate ion in the boron-containing solution is 0.5-2 g / L.

15. The method of claim 4, wherein the method further comprises: The initial flow rate of the fluorine-containing solution is 0.8-2 L / h.

16. The method of claim 4, wherein the method further comprises: The initial flow rate of the boron-containing solution is 0.1-1 L / h.

17. The method of claim 4, wherein the method further comprises: The reaction temperature of the co-precipitation reaction is 40-60 °C.

18. The method of making a cathode precursor material of claim 4, wherein, The pH value of the co-precipitation reaction is 8-12.

19. The method of claim 4, wherein the method further comprises, After the co-precipitation reaction, aging is performed.

20. The method of claim 19, wherein the method further comprises: The aging time is 2-18 h.

21. The method of making a cathode precursor material of claim 4, wherein, The preparation method comprises the following steps: The main metal element salt solution, the precipitant solution, the complexing agent solution, the fluorine-containing solution with a fluorine ion concentration of 0.5-2 g / L and the boron-containing solution with a borate ion concentration of 0.5-2 g / L are added into the bottom liquid in parallel in an environment with a pH value of 8-12 to perform a co-precipitation reaction, and during the co-precipitation reaction, the initial flow rate of the fluorine-containing solution is 0.1-1 L / h and the flow rate gradually increases, and the initial flow rate of the boron-containing solution is 0.8-2 L / h and the flow rate gradually decreases; wherein the main metal element in the main metal element salt solution and Ni x Co y M 1-x-y R z the metal element in the metal element salt solution is consistent.

22. A positive electrode material, characterized in that, The positive electrode material is obtained by mixing and sintering the positive electrode precursor material according to any one of claims 1-3 with a lithium salt or a sodium source.

23. A battery, characterized by The battery comprises the positive electrode material according to claim 22.

24. The battery of claim 23, wherein, The battery comprises a lithium ion battery and / or a sodium ion battery.

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