A porous precursor material, a preparation method therefor and applications thereof

Abstract

The application provides a porous precursor material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing a metal salt solution, a complexing agent, a precipitating agent and a pore-forming agent, performing a co-precipitation reaction, and performing post-treatment after the reaction is completed to obtain an intermediate product; mixing the intermediate product with a solvent, and then introducing carbon dioxide to perform a reaction to obtain the porous precursor material; and the preparation method can make the pores uniformly distributed in the precursor by introducing the pore-forming agent and cooperating with a two-step method, increase the diffusion channel of lithium ions, make the capacity of the positive electrode material fully play, and significantly improve the electrochemical performance of the positive electrode material.

Description

Technical Field

[0001] This invention belongs to the field of battery technology and relates to a porous precursor material, its preparation method and application. Background Technology

[0002] Cobalt-free high-nickel materials have both price and capacity advantages, which has attracted the attention of many researchers in recent years. However, their single-crystal materials have the problem of insufficient capacity release. The reason is that the precursor used to prepare the cathode material is too dense, which affects the diffusion of lithium ions and thus prevents its electrochemical performance from being fully realized.

[0003] Currently, the pore structure during the preparation of porous precursors is uncontrollable in existing technologies. For example, CN 109616664A discloses a method for preparing nickel-cobalt-manganese precursors, nickel-cobalt-manganese ternary materials, and lithium-ion batteries. It starts with the preparation of high-nickel ternary material precursors, using organic polymer particles as pore-forming agents and the carbonized material after lithiation sintering as reducing agents to prepare high-nickel ternary cathode materials with internal voids in secondary particles and transition metal ion gradient layers in primary particles. Organic pore-forming agents are added and carbonized in the subsequent sintering process to form a pore structure. This is not a porous precursor, therefore, the pore structure is uncontrollable and impurities are introduced.

[0004] Based on the above research, there is a need to provide a method for preparing porous precursor materials. This method can obtain porous precursor materials with controllable and uniform pore distribution, thereby increasing the diffusion channels of lithium ions and improving the electrochemical performance of the battery. Summary of the Invention

[0005] The purpose of this invention is to provide a porous precursor material, its preparation method and application, and in particular, a cobalt-free high-nickel porous precursor material, its preparation method and application. The preparation method, by introducing a pore-forming agent and using a two-step method, enables the pores to be uniformly distributed inside the precursor, increases the diffusion channels of lithium ions, allows the cathode material to fully utilize its capacity, and significantly improves the electrochemical performance of the cathode material.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a porous precursor material, the method comprising the following steps:

[0008] (1) Mix the metal salt solution, complexing agent, precipitant and pore-forming agent, and carry out a co-precipitation reaction. After the reaction is completed, perform post-treatment to obtain the intermediate product.

[0009] (2) The intermediate product described in step (1) is mixed with a solvent, and then carbon dioxide is introduced to react and obtain the porous precursor material.

[0010] This invention employs a two-step method to prepare porous precursor materials. In step (1), a co-precipitation reaction is carried out, and a pore-forming agent is added during the co-precipitation process. This allows the precipitate to combine with the pore-forming agent during growth, resulting in intermediate product particles. The intermediate product is then transferred to another reaction vessel, where a solvent is added and carbon dioxide is introduced. The pore-forming agent in the intermediate product reacts with the carbon dioxide, thereby removing the pore-forming agent from the intermediate product and achieving pore formation. This yields a precursor material with uniform pore distribution, enhances the lithium-ion diffusion channels, promotes the capacity of the cathode material, and thus improves the electrochemical performance of the cathode material.

[0011] Preferably, the pore-forming agent in step (1) includes a carbonate, preferably any one or a combination of at least two of lithium carbonate, magnesium carbonate or calcium carbonate.

[0012] Preferably, the concentration of the pore-forming agent in step (1) is 20-80 g / L, for example, it can be 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L or 80 g / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] This invention utilizes the characteristic that carbonates are slightly soluble in coprecipitation reaction systems, allowing the particles to combine with carbonates during growth. Then, carbon dioxide reacts with the carbonates to generate bicarbonates that are soluble in the coprecipitation system, thus achieving pore formation. Therefore, the concentration of the pore-forming agent in this invention needs to be within a specific range to avoid situations where there is too little pore-forming agent, resulting in the absence of pore-forming agent or insufficient pore-forming agent in the coprecipitation system, which would prevent effective pore formation. At the same time, if there is too much pore-forming agent, it will affect the growth of particles during the coprecipitation reaction and reduce the sphericity of the particles.

[0014] Preferably, a reducing agent is also added during the mixing process in step (1).

[0015] In step (1), a reducing agent is also added to provide a reducing atmosphere.

[0016] Preferably, the reducing agent comprises hydrazine hydrate.

[0017] Preferably, the mixing in step (1) includes adding the metal salt solution, complexing agent and precipitant to the bottom liquid in a co-precipitation reaction, and adding the pore-forming agent when the particle size of the precipitate is 0-2 μm, for example, 0 μm, 0.5 μm, 1 μm, 1.5 μm or 2 μm.

[0018] This invention does not impose specific limitations on the timing of adding or stopping the pore-forming agent. It can be reasonably selected according to the required pore structure. For example, if pores are required when the particle is 1-2 μm away from the core, the pore-forming agent can be added when the co-precipitation reaction reaches 1 μm and the addition can be stopped when the particle grows to 2 μm. If pores are required to be evenly distributed inside the particle, the pore-forming agent can be added continuously from the beginning to the end of the reaction.

[0019] The addition of a pore-forming agent when the co-precipitation reaction reaches a particle size of 0 μm means that the pore-forming agent is added together with other raw materials for the reaction.

[0020] Preferably, the pore-forming agent described in step (1) is added to the bottom liquid in parallel with the metal salt solution, complexing agent and precipitant.

[0021] Since a uniform distribution of pores within the cathode material is more conducive to its capacity utilization, this invention preferably adds the pore-forming agent together with other co-precipitation reaction raw materials to achieve uniform compounding of the pore-forming agent and co-precipitation product particles, thereby achieving uniform pore formation.

[0022] Preferably, the flow rate of the metal salt solution added in co-current flow in step (1) is 350-450 mL / h, for example, 350 mL / h, 400 mL / h or 450 mL / h, and the flow rate of the complexing agent added in co-current flow is 50-150 mL / h, for example, 50 mL / h, 100 mL / h or 150 mL / h, but not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0023] This invention does not specifically limit the flow rate of the precipitant, but adjusts the flow rate according to the pH. Preferably, the flow rate of the pore-forming agent added in step (1) is 50-150 mL / h, for example, it can be 50 mL / h, 100 mL / h or 150 mL / h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] Preferably, the base liquid comprises water, a reducing agent, and a complexing agent.

[0025] Preferably, in the metal salt solution of step (1), the total concentration of metal ions is 2-3 mol / L, for example, it can be 2 mol / L, 2.5 mol / L or 3 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the metal salt solution in step (1) includes nickel salt and manganese salt.

[0027] The method of the present invention can prepare cobalt-free high-nickel precursor materials.

[0028] Preferably, the concentration of the complexing agent in step (1) is 10-80 mL / L, for example, it can be 10 mL / L, 20 mL / L, 30 mL / L, 40 mL / L, 50 mL / L, 60 mL / L, 70 mL / L or 80 mL / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] The concentration unit of the complexing agent described in this invention is mL / L, which refers to how many milliliters of complexing agent are contained in 1L of water.

[0030] Preferably, the concentration of the precipitant in step (1) is 5-10 mol / L, for example, it can be 5 mol / L, 8 mol / L or 10 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0031] Preferably, the complexing agent in step (1) includes ammonia water, and the precipitant includes sodium hydroxide solution and / or potassium hydroxide solution.

[0032] Preferably, the temperature of the coprecipitation reaction in step (1) is 40-70℃, for example, 40℃, 50℃, 60℃ or 70℃, the pH is 10-11.1, for example, 10.0, 10.5 or 11.1, and the rotation speed is 200-1200rpm, for example, 200rpm, 500rpm, 1000rpm or 1200rpm, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0033] Preferably, the endpoint of the coprecipitation reaction in step (1) is that the particle size of the precipitate is 2.5-3.5 μm, for example, it can be 2.5 μm, 3.0 μm or 3.5 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] Preferably, the post-processing in step (1) includes washing and solid-liquid separation performed sequentially.

[0035] Preferably, the carbon dioxide inlet rate in step (2) is 0.1-0.5 mol / h, for example, it can be 0.1 mol / h, 0.2 mol / h, 0.3 mol / h, 0.4 mol / h or 0.5 mol / h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0036] In step (2) of this invention, carbon dioxide participates in the pore-forming reaction. Its introduction rate will affect the pore-forming effect. If the carbon dioxide is introduced too quickly, the raw materials cannot be fully utilized. If the carbon dioxide is introduced too slowly, the reaction efficiency will be reduced.

[0037] Preferably, the reaction temperature in step (2) is 35-60℃, for example, 35℃, 45℃, 55℃ or 60℃, the time is 5-14h, for example, 5h, 7h, 9h, 11h, 13h or 14h, and the rotation speed is 100-500rpm, for example, 100rpm, 200rpm, 300rpm, 400rpm or 500rpm, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] The reaction time described in step (2) of this invention will also affect the pore-forming effect. If the reaction time is too short, the pore-forming agent cannot be effectively dissolved. If the reaction time is too long, the stability of the product will be affected because the system in step (2) is acidic.

[0039] Preferably, the solvent in step (2) includes water.

[0040] In this invention, both steps (1) and (2) are carried out in water to match the characteristics that carbonates are not easily soluble in water while bicarbonates are easily soluble in water, thereby achieving pore formation.

[0041] As a preferred embodiment of the preparation method of the present invention, the preparation method includes the following steps:

[0042] (1) At a temperature of 40-70℃ and a rotation speed of 200-1200rpm, a metal salt solution with a total metal ion concentration of 2-3mol / L, a complexing agent with a concentration of 10-80mL / L, and a precipitant with a concentration of 5-10mol / L are added to the bottom liquid in a co-precipitation reaction. When the co-precipitation reaction reaches a particle size of 0-2μm, a pore-forming agent with a concentration of 20-80g / L is added to carry out the co-precipitation reaction. The pH of the co-precipitation reaction is 10-11.1. After the reaction reaches a particle size of 2.5-3.5μm, the product is washed and separated into solid and liquid components to obtain an intermediate product.

[0043] The base liquid includes water, a reducing agent, and a complexing agent;

[0044] (2) The intermediate product described in step (1) is mixed with a solvent, and then carbon dioxide is introduced at a temperature of 35-60°C and a rotation speed of 100-500 rpm for 5-14 hours to obtain the porous precursor material.

[0045] In a second aspect, the present invention provides a porous precursor material, which is prepared by the preparation method described in the first aspect.

[0046] Thirdly, the present invention provides a cathode material, which is obtained by mixing and sintering a lithium source with the porous precursor material described in the second aspect.

[0047] Fourthly, the present invention provides a battery comprising the positive electrode material as described in the third aspect.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] This invention employs a two-step process: first, a pore-forming agent is combined with a co-precipitated product to obtain intermediate product particles; then, carbon dioxide is introduced to react the pore-forming agent in the intermediate product with the carbon dioxide, thereby removing the pore-forming agent from the intermediate product and achieving pore formation. This results in a precursor material with controllable and uniform pore distribution, enhancing lithium-ion diffusion channels, promoting the capacity of the cathode material, and thus improving the electrochemical performance of the cathode material. Attached Figure Description

[0050] Figure 1 This is a cross-sectional view of the porous precursor material described in Embodiment 1 of the present invention.

[0051] Figure 2 This is a cross-sectional view of the porous precursor material described in Embodiment 4 of the present invention.

[0052] Figure 3 This is a cross-sectional view of the porous precursor material described in Comparative Example 1 of the present invention. Detailed Implementation

[0053] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0054] Example 1

[0055] This embodiment provides a method for preparing a porous precursor material, the method comprising the following steps:

[0056] (1) At a temperature of 45℃ and a rotation speed of 1200rpm, a metal salt solution, ammonia water with a concentration of 25mL / L, sodium hydroxide solution with a concentration of 5mol / L and pore-forming agent with a concentration of 45g / L were added to the bottom liquid in parallel to carry out a co-precipitation reaction. The pH of the co-precipitation reaction was 10.5. After the precipitate particle size was 3μm, it was washed and filtered to obtain an intermediate product.

[0057] The metal salt solution comprises 0.10 mol / L manganese sulfate and 1.90 mol / L nickel sulfate; the metal salt solution is added in a co-current flow rate of 400 mL / h, the ammonia solution is added in a co-current flow rate of 100 mL / h, and the pore-forming agent is added at a flow rate of 100 mL / h.

[0058] The pore-forming agent is a lithium carbonate suspension with a concentration of 45 g / L, and the base solution is 4 L of water, 10 mL of hydrazine hydrate and 12 mL of ammonia.

[0059] (2) The intermediate product described in step (1) is mixed with water in a reactor, and then carbon dioxide is introduced at a rate of 0.2 mol / h at a speed of 300 rpm for 12 h. After that, the mixture is washed, filtered, dried, sieved and demagnetized to obtain the porous precursor material.

[0060] The particle cross-sectional diagram of the porous precursor material obtained in this embodiment is shown below. Figure 1 As shown.

[0061] Example 2

[0062] This embodiment provides a method for preparing a porous precursor material, the method comprising the following steps:

[0063] (1) At a temperature of 45℃ and a rotation speed of 1200rpm, a metal salt solution, ammonia water with a concentration of 25mL / L, sodium hydroxide solution with a concentration of 5mol / L and a pore-forming agent were added to the bottom liquid in a co-precipitation reaction. The pH of the co-precipitation reaction was 10.5. After the precipitate reached a particle size of 3μm, it was washed and filtered to obtain an intermediate product.

[0064] The metal salt solution comprises 0.10 mol / L manganese sulfate and 1.90 mol / L nickel sulfate; the metal salt solution is added in a co-current flow rate of 400 mL / h, the ammonia solution is added in a co-current flow rate of 100 mL / h, and the pore-forming agent is added at a flow rate of 50 mL / h.

[0065] The pore-forming agent is a lithium carbonate suspension with a concentration of 80 g / L, and the base solution is 4 L of water, 10 mL of hydrazine hydrate and 12 mL of ammonia.

[0066] (2) The intermediate product described in step (1) is mixed with water in a reactor, and then carbon dioxide is introduced at a rate of 0.5 mol / h at a speed of 300 rpm for 14 h. After that, the mixture is washed, filtered, dried, sieved and demagnetized to obtain the porous precursor material.

[0067] Example 3

[0068] This embodiment provides a method for preparing a porous precursor material, the method comprising the following steps:

[0069] (1) At a temperature of 45℃ and a rotation speed of 1200rpm, a metal salt solution, ammonia water with a concentration of 25mL / L, sodium hydroxide solution with a concentration of 5mol / L and a pore-forming agent were added to the bottom liquid in a co-precipitation reaction. The pH of the co-precipitation reaction was 10.5. After the precipitate reached a particle size of 3μm, it was washed and filtered to obtain an intermediate product.

[0070] The metal salt solution comprises 0.10 mol / L manganese sulfate and 1.90 mol / L nickel sulfate; the metal salt solution is added in a co-current flow rate of 400 mL / h, the ammonia solution is added in a co-current flow rate of 100 mL / h, and the pore-forming agent is added at a flow rate of 100 mL / h.

[0071] The pore-forming agent is a lithium carbonate suspension with a concentration of 20 g / L, and the base solution is 4 L of water, 10 mL of hydrazine hydrate and 12 mL of ammonia.

[0072] (2) The intermediate product described in step (1) is mixed with water in a reactor, and then carbon dioxide is introduced at a rate of 0.1 mol / h at a speed of 300 rpm for 5 h. After that, the mixture is washed, filtered, dried, sieved and demagnetized to obtain the porous precursor material.

[0073] Example 4

[0074] This embodiment provides a method for preparing a porous precursor material. Except for step (1), in which the pore-forming agent is added when the particle size of the precipitate grows to 2 μm and is stopped when the particle size of the precipitate grows to 2.5 μm, the preparation method is the same as in Example 1.

[0075] The particle cross-sectional diagram of the porous precursor material obtained in this embodiment is shown below. Figure 2 As shown.

[0076] Example 5

[0077] This embodiment provides a method for preparing a porous precursor material. Except for the concentration of the pore-forming agent in step (1) being 5 g / L, the preparation method is the same as in Example 1.

[0078] Example 6

[0079] This embodiment provides a method for preparing a porous precursor material. Except for the concentration of the pore-forming agent in step (1) being 100 g / L, the preparation method is the same as in Example 1.

[0080] Example 7

[0081] This embodiment provides a method for preparing a porous precursor material. Except for the carbon dioxide introduction rate of 0.01 mol / h in step (2), the preparation method is the same as in Example 1.

[0082] Example 8

[0083] This embodiment provides a method for preparing a porous precursor material. Except for the carbon dioxide introduction rate of 1 mol / h in step (2), the preparation method is the same as in Example 1.

[0084] Example 9

[0085] This embodiment provides a method for preparing a porous precursor material. Except for the reaction time of 4 hours in step (2), the preparation method is the same as that in Example 1.

[0086] Example 10

[0087] This embodiment provides a method for preparing a porous precursor material. Except for the reaction time of 16 hours in step (2), the preparation method is the same as that in Example 1.

[0088] Comparative Example 1

[0089] This comparative example provides a method for preparing a porous precursor material. The preparation method is the same as that in Example 1, except that no pore-forming agent is added in step (1) and step (2) is performed.

[0090] The particle cross-sectional diagram of the porous precursor material obtained in this comparative example is shown below. Figure 3 As shown.

[0091] Comparative Example 2

[0092] This comparative example provides a method for preparing a porous precursor material, which is the same as that in Example 1 except that step (2) is not performed.

[0093] Comparative Example 3

[0094] This comparative example provides a method for preparing a porous precursor material. In the preparation method, except that after reacting to the particle size of the precipitate in step (1) until it reaches 3 μm, the addition of metal salt solution, ammonia, sodium hydroxide solution and pore-forming agent is stopped, and then carbon dioxide is introduced at a rate of 2 mol / h to react for 12 h, followed by washing, filtration, drying, sieving and demagnetization to obtain the porous precursor material.

[0095] The porous precursor materials obtained in the above examples and comparative examples were tested for specific surface area and tap density, and were thoroughly mixed with lithium hydroxide at a ratio of 1:1.02. The mixture was calcined at 800°C for 10 hours in an oxygen atmosphere, and then crushed and sintered again at 700°C for 8 hours to generate a cobalt-free cathode material. This material was mixed with SP (carbon black conductive agent), CNT (carbon nanotubes), and PVDF (polyvinylidene fluoride), and slurried with NMP (N-methylpyrrolidone) as solvent to obtain a cathode slurry. The slurry was then made into an electrode sheet, and a lithium-ion half-cell was obtained. The specific capacity and 50-cycle retention rate of the cathode were tested at 25°C and a charge-discharge rate of 1C.

[0096] The test results are shown in Table 1:

[0097] Table 1

[0098]

[0099] As can be seen from Table 1:

[0100] (1) The cathode material prepared by the preparation method of the present invention has a 1C capacity of 190-205mAh / g and a 50-cycle retention rate of 92-96%, which significantly improves the electrochemical performance of the cathode material. As can be seen from Example 1 and Comparative Example 1, when no pore-forming agent is added and step (2) is not performed, a dense precursor material is prepared, which has a lower performance than the porous material in Example 1. As can be seen from Example 1 and Comparative Example 2, even if a pore-forming agent is added, but step (2) is not performed, the precursor cannot be pore-formed, and the performance of the obtained cathode material is lower. As can be seen from Example 1 and Comparative Example 3, even if a pore-forming agent is added and carbon dioxide is introduced to remove the pore-forming agent and form pores, but a stepwise reaction is not performed, since step (1) co-precipitates into an alkaline system, carbon dioxide needs to neutralize the alkalinity of the system first, and cannot react with the pore-forming agent, so pores cannot be formed.

[0101] (2) At the same time, combined with Figure 3 It can be seen that without drilling, the resulting material is dense, due to... Figure 1 and Figure 2 The present invention can obtain a structure with uniform pore distribution in the particles and pores only within a specific thickness range. Therefore, the preparation method of the present invention achieves controllable pore distribution. As can be seen from Examples 1 and 5-6, the concentration of the pore-forming agent will affect its composite effect and degree with the precipitate, thereby affecting the pore formation. As can be seen from Examples 1 and 7-10, the rate of carbon dioxide introduction and the reaction time in step (2) will also affect the pore formation result, thereby affecting the performance.

[0102] In summary, this invention provides a porous precursor material, its preparation method, and its application. The preparation method, by introducing a pore-forming agent and combining it with a two-step process, can obtain a porous precursor material, increasing the diffusion channels of lithium ions, allowing the cathode material to fully utilize its capacity, and significantly improving the electrochemical performance of the cathode material.

[0103] 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 method for preparing a cobalt-free, high-nickel porous precursor material, characterized in that, The preparation method includes the following steps: (1) Add the metal salt solution, complexing agent and precipitant to the bottom liquid in a co-current manner. When the co-precipitation reaction reaches the particle size of the precipitate of 0-2 μm, start adding the pore-forming agent in a co-current manner to carry out the co-precipitation reaction. After the reaction is completed, wash and solid-liquid separation are performed to obtain the intermediate product. The pore-forming agent comprises a carbonate; the concentration of the pore-forming agent is 20-80 g / L; the flow rate at which the pore-forming agent is added is 50-150 mL / h; (2) The intermediate product described in step (1) is mixed with a solvent, and then carbon dioxide is introduced to react and obtain the porous precursor material; the solvent includes water.

2. The preparation method according to claim 1, characterized in that, The carbonate includes any one or a combination of at least two of lithium carbonate, magnesium carbonate, or calcium carbonate.

3. The preparation method according to claim 1, characterized in that, A reducing agent was also added during the mixing process described in step (1).

4. The preparation method according to claim 3, characterized in that, The reducing agent includes hydrazine hydrate.

5. The preparation method according to claim 1, characterized in that, In step (1), the pore-forming agent, metal salt solution, complexing agent, and precipitant are added to the bottom liquid in a co-current flow.

6. The preparation method according to claim 1, characterized in that, In step (1), the metal salt solution is added in a co-current flow rate of 350-450 mL / h, and the complexing agent is added in a co-current flow rate of 50-150 mL / h.

7. The preparation method according to claim 1, characterized in that, The base liquid includes water, a reducing agent, and a complexing agent.

8. The preparation method according to claim 1, characterized in that, In step (1), the total concentration of metal ions in the metal salt solution is 2-3 mol / L.

9. The preparation method according to claim 1, characterized in that, The metal salt solution in step (1) includes nickel salt and manganese salt.

10. The preparation method according to claim 1, characterized in that, The concentration of the complexing agent in step (1) is 10-80 mL / L.

11. The preparation method according to claim 1, characterized in that, The concentration of the precipitant in step (1) is 5-10 mol / L.

12. The preparation method according to claim 1, characterized in that, The complexing agent in step (1) includes ammonia, and the precipitant includes sodium hydroxide solution and / or potassium hydroxide solution.

13. The preparation method according to claim 1, characterized in that, The temperature of the coprecipitation reaction in step (1) is 40-70℃, the pH is 10-11.1, and the rotation speed is 200-1200rpm.

14. The preparation method according to claim 1, characterized in that, The endpoint of the coprecipitation reaction in step (1) is when the particle size of the precipitate is 2.5-3.5 μm.

15. The preparation method according to claim 1, characterized in that, The carbon dioxide inlet rate in step (2) is 0.1-0.5 mol / h.

16. The preparation method according to claim 1, characterized in that, The reaction in step (2) is carried out at a temperature of 35-60℃ for 5-14 hours and at a speed of 100-500 rpm.

17. The preparation method according to any one of claims 1-16, characterized in that, The preparation method includes the following steps: (1) At a temperature of 40-70℃ and a rotation speed of 200-1200rpm, a metal salt solution with a total metal ion concentration of 2-3mol / L, a complexing agent with a concentration of 10-80mL / L, and a precipitant with a concentration of 5-10mol / L are added to the bottom liquid in a co-precipitation reaction. When the co-precipitation reaction reaches a particle size of 0-2μm, a pore-forming agent with a concentration of 20-80g / L is added to carry out the co-precipitation reaction. The pH of the co-precipitation reaction is 10-11.

1. After the reaction reaches a particle size of 2.5-3.5μm, the product is washed and separated into solid and liquid components to obtain an intermediate product. The base liquid includes water, a reducing agent, and a complexing agent; (2) The intermediate product described in step (1) is mixed with a solvent, and then carbon dioxide is introduced at a temperature of 35-60°C and a rotation speed of 100-500 rpm for 5-14 hours to obtain the porous precursor material.

18. A cobalt-free, high-nickel porous precursor material, characterized in that, The porous precursor material is prepared using the preparation method described in any one of claims 1-17.

19. A positive electrode material, characterized in that, The cathode material is obtained by mixing and sintering a lithium source and a porous precursor material as described in claim 18.

20. A battery, characterized in that, The battery includes the positive electrode material as described in claim 19.

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