Ternary positive electrode material precursor, preparation method and use

Abstract

The present disclosure relates to the technical field of positive electrode materials for lithium-ion batteries. Disclosed are a ternary positive electrode material precursor, a preparation method and the use. The general formula of the ternary positive electrode material precursor is NiaCobM1-a-b(OH)2, wherein 0.3≤a<0.98, 0<b<0.5, 0<1-a-b<0.5, and M is selected from at least one of Mn and Al. The ternary positive electrode material precursor comprises effective pores and ineffective pores, wherein the effective pores are pores that water can enter under standard atmospheric pressure, the ineffective pores are pores that water cannot enter under standard atmospheric pressure, and the specific porosity of the effective pores in the ternary positive electrode material precursor is 75-90%. The residual quantity of impurities in the ternary positive electrode material precursor prepared in the present disclosure is relatively small; when same is used to prepare a positive electrode material, the entrance of lithium into the material is facilitated, thereby forming a positive electrode material with complete crystals and uniform element distribution; and when the positive electrode material prepared therefrom is used in a lithium-ion battery, the lithium-ion battery is enabled to have a relatively good cycling stability and rate capability.

Description

Ternary cathode material precursor, preparation method and application

[0001] Cross-reference to related applications

[0002] The present disclosure claims priority to the Chinese patent application No. 202410649899.3, filed on May 24, 2024, entitled "Ternary cathode material precursor, preparation method and application", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of lithium ion battery cathode materials, in particular, to a ternary cathode material precursor, a preparation method and application thereof. BACKGROUND

[0004] In order to solve the environmental problems caused by the use of fossil fuels by automobiles, new energy vehicles have attracted much attention due to their green and sustainable development advantages. As the power support for new energy vehicles, the rapid development of lithium ion batteries has driven the rapid development of ternary cathode materials. Ternary cathode materials have the advantages of high specific capacity, moderate price, low toxicity, and relatively abundant resources.

[0005] Ternary cathode materials are usually prepared by mixing and calcining ternary cathode material precursors, nickel-cobalt-manganese hydroxide or nickel-cobalt-aluminum hydroxide, and a lithium source. The ternary cathode material precursor is usually a porous spherical body, which is a secondary particle formed by the mutual lapping of primary particles. The porous structure is composed of internal spaces formed by the mutual lapping of primary particles during agglomeration. In order to improve the transmission efficiency of lithium ions, the specific pore volume and specific surface area are usually increased to increase the number of active sites. However, in some cases, the increase in specific pore volume or specific surface area may reduce the transmission efficiency of lithium ions, thereby affecting the accuracy of performance estimation of ternary cathode materials and resulting in the inability to obtain ternary cathode materials with good performance.

[0006] In view of this, the present disclosure is proposed.

[0007] SUMMARY

[0008] The present disclosure aims to provide a ternary cathode material precursor, a preparation method and application, and to improve the lithium ion transmission efficiency of the corresponding ternary cathode material.

[0009] The present disclosure is implemented as follows:

[0010] In a first aspect, the present disclosure provides a ternary cathode material precursor, the general formula of which is Ni a Co b M 1-a-b(OH)2, wherein 0.3≤a<0.98, 0<b<0.5, 0<1-a-b<0.5, and M is at least one of Mn and Al; the ternary cathode material precursor comprises effective pores and ineffective pores, the effective pores refer to pores into which water can enter under standard atmospheric pressure, the ineffective pores refer to pores into which water cannot enter under standard atmospheric pressure, and the effective specific pore volume of the ternary cathode material precursor is 75% to 90%;

[0011] wherein the effective specific pore volume = V 有效 / V 孔 ×100%, V 有效 is the specific pore volume of the effective pores, and the unit is cm 3 / g, V 无效 is the specific pore volume of the ineffective pores, and the unit is cm 3 / g; V 孔 = V 有效 + V 无效 .

[0012] In some embodiments, the ternary cathode material precursor satisfies at least one of the following ① to ⑥:

[0013] ① V 孔 is 0.01 cm 3 / g to 0.06 cm 3 / g;

[0014] ② V 有效 = V 总 -V 排 , V 孔 = V 总 -V 材 ; wherein,

[0015] V 总 = V 材 + V 有效 + V 无效 , which refers to the volume of mercury displaced by unit mass of the ternary cathode material precursor immersed in mercury, and the unit is cm 3 / g;

[0016] V 排 = V 材 + V 无效 , which refers to the volume of water displaced by unit mass of the ternary cathode material precursor immersed in water, and the unit is cm 3 / g;

[0017] V 材 is the reciprocal of the density of the ternary cathode material precursor;

[0018] ③ the V 有效 and V 孔 are tested at a temperature of 4℃ to 80℃;

[0019] IV. the D50 of the ternary positive electrode material precursor is 8 μm to 12 μm;

[0020] V. the specific surface area of the ternary positive electrode material precursor is 6.4 m 2 / g to 7.5 m 2 / g;

[0021] VI. the tap density of the ternary positive electrode material precursor is 1.9 g / cm 3 to 2.3 g / cm 3 .

[0022] In some embodiments, the total weight percentage of sodium and sulfur in the ternary positive electrode material precursor is less than 0.21 wt%;

[0023] and / or, the weight percentage of sodium in the ternary positive electrode material precursor is less than 0.03 wt%;

[0024] and / or, the weight percentage of sulfur in the ternary positive electrode material precursor is less than 0.21 wt%.

[0025] In a second aspect, the present disclosure provides a preparation method of the ternary positive electrode material precursor according to the foregoing embodiments, comprising:

[0026] seed preparation, preparing nano-crystal seeds of the ternary positive electrode material precursor by using a co-precipitation method under high gravity conditions;

[0027] seed growth, growing the nano-crystal seeds to obtain the ternary positive electrode material precursor.

[0028] In some embodiments, the seed preparation step comprises: placing ammonia water with a pH of 10 to 11 as a reaction base solution in a rotating bed reactor, placing a nickel-cobalt M mixed salt solution and a mixed aqueous solution containing a precipitating agent and a complexing agent in two liquid holding tanks of the rotating bed respectively, and flowing into the rotating bed reactor, so that the pH value is maintained at 10.5 to 11.5, until the precipitation reaches a first preset particle size, the feeding is stopped and the rotating bed is stopped rotating, and the first reaction liquid containing seeds is obtained after standing and aging, and the seed preparation step further satisfies at least one of the following A-I:

[0029] A. the D50 of the first preset particle size is 200 nm to 500 nm;

[0030] B. in the mixed aqueous solution, the concentration of the precipitating agent is 3 mol / L to 5 mol / L, and the concentration of the complexing agent is 1.5 mol / L to 2.5 mol / L.

[0031] C. the rotating speed of the rotating bed is 1000 rpm to 1500 rpm.

[0032] D. the salt in the nickel-cobalt M mixed salt solution is one of nitrate, chloride or sulfate;

[0033] E. the molar ratio of nickel-cobalt M is 35-98: 1-35: 1-35;

[0034] F. the total concentration of nickel, cobalt and M in the nickel-cobalt M mixed salt solution is 1.5-2.5 mol / L;

[0035] G. the flow rate of the nickel-cobalt M mixed salt solution is 50-100 mL / min.

[0036] H. the precipitant is potassium hydroxide or sodium hydroxide.

[0037] I. the complexing agent is one of ammonia, ammonium nitrate, ammonium sulfate and ammonium chloride.

[0038] In some embodiments, the seed crystal growth step comprises: adjusting the pH of the first reaction solution containing seed crystals to 9.5-10.5, then adding the nickel-cobalt M mixed salt solution, an aqueous solution of a crystal form regulator, and a mixed aqueous solution containing a precipitant and a complexing agent to the first reaction solution containing seed crystals to obtain a second reaction solution and maintain the pH of the second reaction solution at 9.5-10.5 and the ammonia concentration at 0.4-0.8 mol / L, until the precipitation reaches a second predetermined particle size, then stop feeding, and after standing and aging, obtain a slurry containing the ternary positive electrode material precursor, and the seed crystal growth step further satisfies at least one of a-f;

[0039] a. the crystal form regulator is an anionic surfactant;

[0040] b. the concentration of the aqueous solution of the crystal form regulator is 0.01-0.05 mol / L;

[0041] c. the flow rate of the nickel-cobalt M mixed salt solution is 0.2-0.5 mL / min;

[0042] d. the flow rate of the aqueous solution of the crystal form regulator is 0.2-0.5 mL / min;

[0043] e. the D50 of the second predetermined particle size is 8-12 μm;

[0044] f. further comprising solid-liquid separation of the slurry containing the ternary positive electrode material precursor, then sequentially washing, drying, sieving and demagnetizing the solid phase using lye and pure water to obtain the ternary positive electrode material precursor.

[0045] In some embodiments, the crystal form regulator is sodium polyacrylate and sodium lignosulfonate;

[0046] And / or, the lye is a sodium hydroxide solution or a potassium hydroxide solution, with a concentration of 50 g / L to 70 g / L and a temperature of 50℃ to 80℃.

[0047] In a third aspect, the present disclosure provides a ternary positive electrode material, which is obtained by calcining a ternary positive electrode material precursor prepared by the preparation method of any one of the preceding embodiments or the preparation method of any one of the preceding embodiments.

[0048] g. The effective specific pore volume of the ternary positive electrode material is 75% to 90%;

[0049] h. The specific surface area of the ternary positive electrode material is 0.4 m 2 / g to 0.7 m 2 / g;

[0050] i. The tap density of the ternary positive electrode material is 2.6 g / cm 3 to 2.9 g / cm 3 .

[0051] In some embodiments, the first discharge specific capacity of the ternary positive electrode material corresponding to 0.1C is 192 mAh / g to 208 mAh / g;

[0052] And / or, the first discharge specific capacity of the ternary positive electrode material corresponding to 1C is 167 mAh / g to 190 mAh / g;

[0053] And / or, the capacity retention rate of the ternary positive electrode material corresponding to 1C after 100 cycles is 85% to 97%;

[0054] And / or, the first discharge specific capacity of the ternary positive electrode material corresponding to 5C is 142 mAh / g to 165 mAh / g.

[0055] In a fourth aspect, the present disclosure provides a preparation method of a ternary positive electrode material, wherein the ternary positive electrode material is obtained by calcining a ternary positive electrode material precursor prepared by the preparation method of any one of the preceding embodiments or the preparation method of any one of the preceding embodiments.

[0056] In some embodiments, the calcination temperature is 400℃ to 800℃, and the calcination time is 15 h to 20 h.

[0057] In some embodiments, calcination includes a first-stage calcination and a second-stage calcination, wherein the first-stage calcination temperature is 400℃~600℃ and the time is 4h~6h; the second-stage calcination temperature is 750℃~800℃ and the time is 10h~14h.

[0058] In some embodiments, the heating rate during the calcination step is 1.5℃ / min to 2.5℃ / min.

[0059] Fifthly, this disclosure provides a positive electrode sheet, comprising the positive electrode material described in the foregoing embodiments.

[0060] Sixthly, this disclosure provides a single-cell battery containing the positive electrode sheet described in the foregoing embodiments.

[0061] In a seventh aspect, this disclosure provides a lithium-ion battery, including the positive electrode sheet described in the foregoing embodiments.

[0062] Eighthly, this disclosure provides an electrical device including the lithium-ion battery described in the foregoing embodiments.

[0063] This disclosure has the following beneficial effects:

[0064] The ternary cathode material precursor prepared in this disclosure has an effective specific porosity of 75% to 90%, which is beneficial to reducing the residual amount of impurities in the precursor. When using it to prepare cathode materials, it is beneficial for lithium to enter the interior of the material, thereby forming a cathode material with complete crystallization and uniform element distribution. When the cathode material prepared by it is applied in lithium-ion batteries, the lithium-ion batteries have better cycle stability and rate performance. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 shows the appearance or cross-sectional view of the material prepared in Example 1 (A is the SEM image of the precipitate before aging during seed preparation; B is the SEM image of the seed crystal; C is the SEM image of the ternary cathode material precursor; D is the cross-sectional view of the ternary cathode material precursor; E is the SEM image of the ternary cathode material; F is the cross-sectional view of the ternary cathode material).

[0067] Figure 2 is a cross-sectional view of the ternary cathode material after 100 cycles (A is the ternary cathode material prepared in Example 1; B is the ternary cathode material prepared in Comparative Example 4);

[0068] Figure 3 is a cross-sectional view of the ternary cathode material precursor prepared in Comparative Example 1;

[0069] Figure 4 shows the SEM image of the ternary cathode material precursor prepared in Comparative Example 5. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions in the embodiments of this disclosure will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0071] In a first aspect, this disclosure provides a ternary cathode material precursor, wherein the general formula of the ternary cathode material precursor is Ni. a Co b M 1-a-b (OH)2, wherein 0.3≤a<0.98, 0<b<0.5, 0<1-ab<0.5, and M is at least one of Mn and Al; the ternary cathode material precursor includes effective pores and ineffective pores, wherein effective pores refer to pores that water can enter, and ineffective pores refer to pores that water cannot enter, and the effective specific pore volume of the ternary cathode material precursor is 75%~90%;

[0072] Wherein, effective specific porosity = V 有效 / V 孔 ×100%, V 有效 Specific orifice volume refers to the volume of the effective orifice, measured in cm³. 3 / g, V 无效 The specific volume of ineffective holes, measured in cm³. 3 / g;V 孔 =V 有效 +V 无效 .

[0073] The precursor of ternary cathode material is a secondary particle formed by the overlapping of primary particles. Its porous morphology is formed by the internal space created when the primary particles agglomerate and overlap. Some of the internal space is closed, forming closed pores. These closed pores are inherited by the cathode material after lithium addition and sintering. On the one hand, these closed pores can reduce the internal stress generated during the charging and discharging process of lithium battery and suppress the generation of microcracks. On the other hand, these closed pores can also lead to the closure of active sites, making it impossible for the lithium source to penetrate and react, reducing the lithium ion diffusion rate, and thus leading to problems such as a decrease in specific capacity and the residue of impurity elements. Therefore, the size of the closed pores should be within an appropriate range.

[0074] In addition, in order to improve the contact area of the active material and the electrolyte, thereby improving the transmission efficiency of lithium ions, the specific surface area of the positive electrode material is increased in the prior art, but the specific surface area is usually determined by N2 adsorption and desorption test at present, and this index cannot comprehensively reflect the contact degree of the material and the liquid, because the wetting degree of the gas N2 and the liquid (water, electrolyte, etc.) to the material is different, resulting in the case that the specific surface area of some materials is large, but the lithium ion transmission efficiency is low. Therefore, even if the specific surface area and the specific pore volume are combined in the prior art, the ternary positive electrode material or the ternary positive electrode material precursor with relatively optimal performance cannot be relatively accurately obtained.

[0075] In the embodiments of the present disclosure, the pores in the ternary positive electrode material precursor are distinguished, wherein the effective pores refer to the pores into which water can enter, and the ineffective pores refer to the pores into which water cannot enter, and the ineffective pores mainly include closed pores and micropores. The micropores have a too small pore size, and the water or electrolyte is difficult to enter. By distinguishing the effective pores and the ineffective pores, the pores that can contact the electrolyte and are beneficial to the improvement of the lithium ion diffusion rate, i.e., the effective pores, and the pores that cannot contact the electrolyte but can release the internal stress generated in the charging and discharging process of the lithium battery, i.e., the ineffective pores, are distinguished.

[0076] In the embodiments of the present disclosure, the effective specific pore volume rate can be specifically 75%, 77%, 79%, 81%, 83%, 85%, 87%, 89%, 90%, or any value between 75% and 90%. If the effective specific pore volume rate of the ternary positive electrode material precursor is too large, it indicates that the material is more compact inside or the pore size of the material outside is larger. On the one hand, the internal compactness is not conducive to the lithium addition high-temperature solid-phase sintering process, Li is difficult to enter the inside, resulting in a decrease in specific capacity; there is no space for stress dissipation during use, so that internal cracks occur in the material, and the cycle performance decreases; on the other hand, the external pore size is too large, and the specific surface area of the obtained positive electrode material is too large, resulting in an increase in interface reaction and a decrease in cycle performance. If the effective specific pore volume rate of the ternary positive electrode material precursor is too small, it indicates that the material is more loose inside or the pore size of the material outside is smaller. On the one hand, the internal looseness leads to an increase in the number of closed pores in the positive electrode material, thereby reducing the tap density and causing a decrease in specific capacity; water cannot enter the inside during water washing, resulting in an increase in the residual amount of sodium and sulfur elements, thereby affecting the electrical performance; on the other hand, the external pore size is too small, and the specific surface area of the obtained positive electrode material is too small, resulting in a decrease in the contact area of lithium ions and electrolyte and a decrease in rate performance.

[0077] In addition, it should be noted that when the effective specific pore volume rate is within the range of 75% to 90%, it is beneficial to reduce the residual amount of impurities in the precursor; when the positive electrode material is prepared by using the same, it is beneficial for lithium to enter the inside of the material, thereby forming a positive electrode material with complete crystal and uniform element distribution. The positive electrode material prepared therefrom has relatively optimal cycle stability and rate performance when applied in a lithium ion battery.

[0078] In summary, the effective specific pore volume of the ternary cathode material precursor prepared in the embodiments of the present disclosure is 75% to 90%, which is beneficial to reduce the residual amount of impurities in the precursor; when the cathode material is prepared by using the precursor, it is beneficial to the lithium entering the material inside, thereby forming a cathode material with complete crystal and uniform element distribution; and it is beneficial to improve the cycle stability and lithium ion transport efficiency of the cathode material prepared therefrom.

[0079] In some embodiments, in the ternary cathode material precursor, V 孔 is 0.01 cm 3 / g to 0.06 cm 3 / g, and specifically can be 0.01 cm 3 / g, 0.02 cm 3 / g, 0.03 cm 3 / g, 0.04 cm 3 / g, 0.05 cm 3 / g, 0.06 cm 3 / g, or 0.01 cm 3 / g to 0.06 cm 3 / g. V 孔 is increased, which is beneficial to the lithium ion entering the inside of the precursor in the lithium-added high-temperature solid-phase sintering process, but V 孔 is too large, and the pore structure will also be partially retained in the ternary cathode material, affecting the cycle performance of the ternary cathode material.

[0080] In some embodiments, in the ternary cathode material precursor, V 有效 = V 总 -V 排 , wherein,

[0081] V 总 = V 材 + V 有效 + V 无效 , which refers to the volume of mercury displaced by unit mass of the ternary cathode material precursor immersed in mercury, in units of cm 3 / g;

[0082] V 排 = V 材 + V 无效 , which refers to the volume of water displaced by unit mass of the ternary cathode material precursor immersed in water, in units of cm 3 / g;

[0083] V 材 is the reciprocal of the density of the ternary cathode material precursor.

[0084] In the embodiments of the present disclosure, by controlling V 总 and V 排determination of the specific pore volume of the effective pores, specifically:

[0085] V 总 The method can be measured by the following method: determining the liquid level of mercury in the container filled with mercury, denoted as H0, and placing the ternary positive electrode material precursor into the container filled with mercury. Since the density of the ternary positive electrode material precursor is less than the density of mercury, the material will float on the liquid surface. A volume V' of piston is used to press the material floating on the liquid surface below the liquid surface at a speed lower than 50 mm / min. After the liquid surface is static, the liquid level is measured and denoted as H1. According to H0 and H1 and other shape parameters of the container, the volumes corresponding to the liquid levels H0 and H1 can be calculated as V0 and V1, respectively. That is, V 总 = V1-V0-V' can be calculated. 总 The test principle is that the wettability of mercury to the ternary positive electrode material precursor of the present disclosure is low, so there is no capillary effect, and the surface tension is large, so it cannot enter the micrometer level pores under no external pressure. Therefore, the apparent volume can be measured relatively accurately under this method. In addition, three-dimensional imaging and other image methods can also be used to measure the V 总 of the material.

[0086] V 排 The test method of V 总 may refer to V 排 , only the liquid is replaced with water, and other equivalent methods can also be used to test V 孔 .

[0087] In some embodiments, the ternary positive electrode material precursor has V 总 = V 材 -V 总 ; under the premise of determining V 孔 , only the material density needs to be tested to calculate V 有效 , which is beneficial to simplify the test steps.

[0088] In some embodiments, the ternary positive electrode material precursor has V 孔 and V 有效 The test process is carried out at a temperature of 4℃-80℃ and a standard atmospheric pressure; in order to be able to relatively accurately simulate the wetting of the electrolyte to the positive electrode material when the battery is working, in the embodiments of the present disclosure, V 孔The temperature and pressure involved in the test can be within the battery's operating temperature range, such as 4℃~80℃, and under standard atmospheric pressure. The water involved can be deionized water, sodium hydroxide solution, potassium hydroxide solution, ammonia water, etc. In order to ensure that the material and the liquid can be in full contact, the mixture of ternary cathode material precursor and liquid can be stirred, sonicated, or vibrated, but pressure cannot be applied. Since it takes a certain amount of time for the liquid to immerse in the ternary cathode material precursor, when reading the volume of water or mercury displaced by the ternary cathode material precursor, the reading should be taken only after the volume no longer changes.

[0089] In some embodiments, the D50 of the ternary cathode material precursor is 8 μm to 12 μm, specifically 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, or any value between 8 μm and 12 μm. The larger the particle size of the ternary cathode material precursor, the larger the particle size of the ternary cathode material prepared from it. A larger particle size of the ternary cathode material results in a longer path for lithium-ion insertion / extraction, which is detrimental to capacity improvement.

[0090] In some embodiments, the specific surface area of ​​the ternary cathode material precursor is 6.4 m². 2 / g~7.5m 2 / g, specifically 6.4m 2 / g, 6.5m 2 / g, 6.7m 2 / g, 6.9m 2 / g, 7.1m 2 / g, 7.3m 2 / g, 7.5m 2 / g or 6.5m 2 / g~7.5m 2 Any value between / g. Increasing the specific surface area of ​​the ternary cathode material precursor is beneficial to increasing the specific surface area of ​​the ternary cathode material, which in turn is beneficial to improving the lithium-ion transport efficiency. However, if the specific surface area is too large, it will lead to too much contact area between the ternary cathode material prepared from it and the electrolyte, which may reduce the cycle performance of the ternary cathode material prepared from it.

[0091] In some embodiments, the tap density of the ternary cathode material precursor is 1.9 g / cm³. 3 ~2.3g / cm 3 Specifically, it can be 1.9 g / cm³. 3 2.0g / cm 3 2.1g / cm 3 2.2g / cm 3 2.3g / cm 3 Or 1.9g / cm 3 ~2.3g / cm 3Any value between them. The tap density of the ternary positive electrode material precursor is closely related to the tap density of the ternary material. The higher the tap density of the ternary positive electrode material precursor, the higher the tap density of the ternary material under the same conditions, and the higher the energy density.

[0092] In some embodiments, the total weight percentage of sodium and sulfur in the ternary positive electrode material precursor is less than 0.21wt%.

[0093] In some embodiments, the weight percentage of sodium in the ternary positive electrode material precursor is less than 0.03wt%.

[0094] In some embodiments, the weight percentage of sulfur in the ternary positive electrode material precursor is less than 0.21wt%.

[0095] The disclosure provides a preparation method of the ternary positive electrode material precursor of the foregoing embodiments, comprising:

[0096] Seed preparation, under the condition of high gravity, nano-crystal seeds of the ternary positive electrode material precursor are prepared by co-precipitation method;

[0097] Seed growth, the nano-crystal seeds are grown to obtain the ternary positive electrode material precursor.

[0098] In the disclosure, under the condition of high gravity, nano-crystal seeds of the ternary positive electrode material precursor are prepared by co-precipitation method. The basic principle is to generate a stable and adjustable strong centrifugal field by a high-speed rotating annular rotor. In the high gravity environment, the molecular diffusion and interphase mass transfer between different size molecules are much faster than in the normal gravity field. The material flows and mixes in the high gravity field which is hundreds of thousands of times larger than the earth's gravity. Under the action of huge shear force, the liquid is torn into nanoscale droplets, filaments and membranes, generating a huge phase interface, making the mass transfer rate increase by 1-3 orders of magnitude compared with traditional tower, and the micro-mixing and mass transfer process is greatly strengthened. At the same time, in the high gravity reactor, the extremely short liquid stagnation time and the extremely large supersaturation interface generated by the reaction make the particle size of the product extremely fine and uniform.

[0099] The high gravity co-precipitation method prepares nanoparticles with uniform morphology, and then after aging, the crystal grains are further grown or partially agglomerated. Because the particle size is small and uniform, and the particles are approximately spherical, the internal structure of the crystal nucleus obtained after aging is relatively tight, thereby reducing the invalid specific pore volume. Further, the crystal nucleus is used as a crystal nucleus to perform secondary growth under non-high gravity conditions, and the crystal formed on the surface of the crystal nucleus is relatively loose, thereby forming a precursor material with tight inside and loose outside, and further achieving the target effective specific pore volume.

[0100] In some embodiments, the seed crystal preparation step comprises: placing an ammonia solution with a pH of 10-11 as a reaction base solution in a rotating bed reactor, placing a nickel-cobalt M mixed salt solution and a mixed aqueous solution containing a precipitant and a complexing agent in two liquid holding tanks of the rotating bed respectively, and adding them to the rotating bed reactor, so that the pH value is maintained at 10.5-11.5, specifically, it can be 10.5, 11, 11.5, or any value between 10.5 and 11.5. The feeding is stopped and the rotating bed is stopped when the precipitation reaches the first preset particle size, and the first reaction liquid containing the seed crystal is obtained after standing and aging.

[0101] In the embodiments of the present disclosure, the pH of the reaction base solution can be 10, 10.5, 11, or any value between 10 and 11. The rotating bed reactor can be a spiral channel type rotating bed. The seed crystal prepared in the embodiments of the present disclosure has a relatively compact structure, and the seed crystal structure is compact and has a small particle size, which is beneficial to the improvement of the effective specific pore volume of the precursor.

[0102] In some embodiments, the D50 of the first preset particle size is 200-500 nm, specifically, it can be 200 nm, 300 nm, 400 nm, 500 nm, or any value between 200 nm and 500 nm. The seed crystal has a small particle size, which is beneficial to the improvement of the effective specific pore volume of the precursor.

[0103] In some embodiments, in the mixed aqueous solution, the concentration of the precipitant is 3-5 mol / L, specifically, it can be 3 mol / L, 4 mol / L, 5 mol / L, or any value between 3 mol / L and 5 mol / L. The concentration of the complexing agent is 1.5-2.5 mol / L, specifically, it can be 1.5 mol / L, 2 mol / L, 2.5 mol / L, or any value between 1.5 mol / L and 2.5 mol / L. The precipitant is beneficial to the improvement of the precipitation rate, and the complexing agent such as ammonia is beneficial to the control of the precipitation rate and the obtaining of seed crystals with good sphericity.

[0104] In some embodiments, the rotating speed of the rotating bed is 1000-1500 rpm, specifically, it can be 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm, 1500 rpm, or any value between 1000 rpm and 1500 rpm. Under the same conditions, the increase of the rotating speed of the rotating bed is beneficial to the reduction of the particle size of the seed crystal and the improvement of the uniformity of the particle size distribution of the seed crystal; but if the rotating speed is too high, the structure of the obtained seed crystal is too compact, which can result in too high effective specific pore volume.

[0105] In some embodiments, the salt in the nickel-cobalt M mixed salt solution is one of nitrate, hydrochloride, or sulfate, which has low raw material cost and easy removal of anions.

[0106] In some embodiments, the molar ratio of nickel, cobalt and M in the nickel-cobalt-M mixed salt solution is 35-98: 1-35: 1-35, so as to obtain a ternary positive electrode material precursor of a desired composition.

[0107] In some embodiments, the total concentration of nickel, cobalt and M in the nickel-cobalt-M mixed salt solution is 1.5-2.5 mol / L, and can be specifically 1.5 mol / L, 2 mol / L, 2.5 mol / L or any value between 1.5 mol / L and 2.5 mol / L. This is conducive to controlling the precipitation rate within a reasonable range, so as to regulate the pore structure of the ternary positive electrode material precursor.

[0108] In some embodiments, the flow rate of the nickel-cobalt-M mixed salt solution is 50-100 mL / min, and can be specifically 50 mL / min, 70 mL / min, 90 mL / min, 100 mL / min or any value between 50 mL / min and 100 mL / min. This is conducive to controlling the precipitation rate within a reasonable range, so as to regulate the pore structure of the ternary positive electrode material precursor.

[0109] In some embodiments, the precipitant is potassium hydroxide or sodium hydroxide, which has low raw material cost and the cation is easy to remove.

[0110] In some embodiments, the complexing agent is one of ammonia, ammonium nitrate, ammonium sulfate and ammonium chloride, which has low raw material cost and the anion is easy to remove.

[0111] In some embodiments, the seed crystal growth step comprises adjusting the pH of the first reaction solution containing seed crystals to 9.5-10.5, and can be specifically 9.5, 10, 10.5 or any value between 9.5 and 10.5. Then the nickel-cobalt-M mixed salt solution, the aqueous solution of the crystal form adjusting agent and the mixed aqueous solution containing the precipitant and the complexing agent are added into the first reaction solution containing seed crystals to obtain a second reaction solution, and the pH of the second reaction solution is maintained at 9.5-10.5 and the ammonia concentration is maintained at 0.4-0.8 mol / L until the precipitation reaches a second preset particle size, and then the feeding is stopped. After standing and aging, a slurry containing the ternary positive electrode material precursor is obtained.

[0112] The addition of the crystal form adjusting agent for secondary growth is conducive to the formation of more loose sheet-shaped crystals on the surface of the seed crystals, thereby more conducive to the formation of a precursor material with an inner tight and outer loose structure, and thus achieving the target effective specific pore volume.

[0113] In some embodiments, the crystal form adjusting agent is an anionic surfactant. The anionic surfactant can electrostatically cooperate with the active crystal face of the precursor crystal with positive charge, thereby inhibiting the growth of the crystal face, and thus forming sheet-shaped crystals.

[0114] In some embodiments, the concentration of the aqueous solution of the crystal form regulator is 0.01 mol / L to 0.05 mol / L, and specifically can be 0.01 mol / L, 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, or any value between 0.01 mol / L and 0.05 mol / L. Under the same conditions, the higher the concentration of the crystal form regulator, the higher the concentration of the crystal form regulator in the reaction solution, the more loose the outside of the obtained ternary positive electrode material precursor, the higher the effective specific pore volume, and the less the residual amount of impurity elements in the material.

[0115] In some embodiments, in the seed crystal growth step, the flow rate of the nickel-cobalt M mixed salt solution is 0.2 mL / min to 0.5 mL / min, and specifically can be 0.2 mL / min, 0.3 mL / min, 0.4 mL / min, 0.5 mL / min, or any value between 0.2 mL / min and 0.5 mL / min. Adjusting the flow rate of the nickel-cobalt M mixed salt solution is conducive to controlling the precipitation speed within a reasonable range, so as to regulate the pore structure of the ternary positive electrode material precursor.

[0116] In some embodiments, in the seed crystal growth step, the flow rate of the aqueous solution of the crystal form regulator is 0.2 mL / min to 0.5 mL / min, and specifically can be 0.2 mL / min, 0.3 mL / min, 0.4 mL / min, 0.5 mL / min, or any value between 0.2 mL / min and 0.5 mL / min. Under the same conditions, the higher the flow rate of the crystal form regulator, the higher the concentration of the crystal form regulator in the reaction solution, the more loose the outside of the obtained ternary positive electrode material precursor, the higher the effective specific pore volume, and the less the residual amount of impurity elements in the material.

[0117] In some embodiments, the D50 of the second preset particle size is 8 μm to 12 μm, that is, the particle size of the ternary positive electrode material precursor.

[0118] In some embodiments, further comprising performing solid-liquid separation on the slurry containing the ternary positive electrode material precursor, and then sequentially using lye and pure water to wash, dry, sieve, and remove magnetism from the solid phase to obtain the ternary positive electrode material precursor. When the ternary positive electrode material precursor is washed with lye and pure water, sodium, potassium, sulfur, nitrogen, chlorine, and other impurities introduced into the material together with the nickel-cobalt M mixed salt solution, the precipitant, and the complexing agent can be removed.

[0119] In some embodiments, the crystal form regulator is sodium polyacrylate and sodium lignosulfonate; compared to small molecule anionic surfactants, polyanionic surfactants such as sodium polyacrylate and sodium lignosulfonate can increase steric hindrance, so that the sheet crystals formed on the surface are more loose, thereby forming more effective specific pore volumes.

[0120] In some embodiments, the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution, with a concentration of 50 g / L to 70 g / L and a temperature of 50°C to 80°C. The purpose of the alkali washing is to remove sulfur. Before the alkali washing, the sulfate is in the form of a complex salt in the solid phase. The alkali washing uses hydroxide to displace the sulfate, thereby avoiding the loss of Ni caused by direct water washing.

[0121] Specifically, the selection of the alkali solution can be based on the type of impurities in the ternary positive electrode material precursor. If the impurities include sodium, the alkali solution can be sodium hydroxide. If the impurities include potassium, the alkali solution can be potassium hydroxide. Suitably, increasing the temperature is conducive to the removal of impurities.

[0122] The present disclosure provides a ternary positive electrode material, which is obtained by calcining a mixture of the ternary positive electrode material precursor of the preceding embodiments or the ternary positive electrode material precursor prepared by the preparation method of any one of the preceding embodiments and a lithium source.

[0123] In some embodiments, the effective specific pore volume ratio of the ternary positive electrode material is 75% to 90%, and specifically can be 75%, 77%, 79%, 81%, 83%, 85%, 87%, 89%, 90%, or any value between 75% and 90%. When the effective specific pore volume ratio is too high, the cycle performance can be reduced. When the effective specific pore volume ratio is too low, the specific capacity and rate performance are not improved. When the ratio of the effective pore volume to the total specific pore volume, i.e., the effective specific pore volume ratio, is in the range of 75% to 90%, the positive electrode material balances the transmission efficiency of lithium ions and the cycle performance.

[0124] In some embodiments, the specific surface area of the ternary positive electrode material is 0.4 m 2 / g to 0.7 m 2 / g, and specifically can be 0.4 m 2 / g, 0.5 m 2 / g, 0.6 m 2 / g, 0.7 m 2 / g, or 0.4 m 2 / g to 0.7 m 2 / g. Increasing the specific surface area is conducive to improving the transmission efficiency of lithium ions, but too large a specific surface area can reduce the cycle performance due to excessive contact area with the electrolyte.

[0125] In some embodiments, the tap density of the ternary positive electrode material is 2.6 g / cm 3 ~ 2.9 g / cm 3 , and specifically can be any value between 2.6 g / cm 3 , 2.7 g / cm 3 , 2.8 g / cm 3 , 2.9 g / cm 3 or 2.6 g / cm 3 ~ 2.9 g / cm 3 . The higher the tap density of the ternary positive electrode material, the higher the energy density; but if the tap density of the ternary positive electrode material is too high, the specific pore volume will decrease accordingly, which will increase the difficulty of lithium ion migration.

[0126] In some embodiments, the ternary positive electrode material has a first discharge specific capacity of 192 mAh / g ~ 208 mAh / g at 0.1C;

[0127] and / or, the ternary positive electrode material has a first discharge specific capacity of 167 mAh / g ~ 190 mAh / g at 1C;

[0128] and / or, the ternary positive electrode material has a capacity retention rate of 85% ~ 97% after 100 cycles at 1C;

[0129] and / or, the ternary positive electrode material has a first discharge specific capacity of 142 mAh / g ~ 165 mAh / g at 5C.

[0130] The present disclosure provides a preparation method of a ternary positive electrode material, which comprises mixing a ternary positive electrode material precursor according to any one of the preceding embodiments or a ternary positive electrode material precursor prepared by the preparation method according to any one of the preceding embodiments with a lithium source and then calcining to obtain the ternary positive electrode material.

[0131] In some embodiments, the calcination temperature is 400°C ~ 800°C, and specifically can be 400°C, 500°C, 600°C, 700°C, 800°C or any value between 400°C and 800°C; the calcination time is 15h ~ 20h, and specifically can be 15h, 16h, 17h, 18h, 19h, 20h or any value between 15h and 20h.

[0132] In some embodiments, the calcination comprises one-stage calcination and two-stage calcination, wherein the one-stage calcination temperature is 400°C ~ 600°C, such as 400°C, 500°C, 600°C, etc., and the time is 4h ~ 6h, such as 4h, 5h, 6h, etc.; the two-stage calcination temperature is 750°C ~ 800°C, such as 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, etc., and the time is 10h ~ 14h, such as 10h, 11h, 12h, 13h, 14h, etc.

[0133] In some embodiments, the heating rate in the calcining step is 1.5-2.5°C / min, such as 1.5°C / min, 2°C / min, 2.5°C / min, etc.

[0134] The present disclosure provides a positive electrode tab, comprising the positive electrode material as described in the foregoing embodiments.

[0135] In the positive electrode tab of the present disclosure, the positive electrode material layer generally comprises the positive electrode material as described, and a binder and a conductive agent, and is generally formed by coating a positive electrode slurry, and drying and cold-pressing. The positive electrode slurry is generally formed by dispersing the positive electrode material as described, and a conductive agent and a binder, etc. in a solvent and stirring uniformly. The solvent can be N-methyl pyrrolidone (NMP).

[0136] In some alternative embodiments, the positive electrode material layer can comprise 70-97 wt% of the positive electrode material, based on the total weight of the positive electrode material layer. Alternatively, the weight percentage of the positive electrode material in the positive electrode material layer is 85-97%, 90-97%, or 95-97%. By adjusting the weight percentage of the positive electrode material in the positive electrode material layer, the energy density and cycle life of the lithium ion battery can be further improved.

[0137] In some embodiments, the binder of the positive electrode material layer can comprise one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a modified polymer thereof.

[0138] The conductive agent can improve the electronic conduction performance of the positive electrode material layer. In some alternative embodiments, the positive electrode material layer can comprise 2-20 wt% of the conductive agent, based on the total weight of the positive electrode material layer. Alternatively, the weight percentage of the conductive agent in the positive electrode material layer is 2-10%, or 2-5%.

[0139] In some embodiments, the conductive agent of the positive electrode material layer can comprise one or more of super-conductive carbon, carbon black (such as SuperP, acetylene black, Ketjen black), carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0140] It should be noted that the composition or parameters of each positive electrode material layer given in the present disclosure refer to the composition or parameter range of the single surface film layer of the positive electrode current collector. When the positive electrode material layer is arranged on the opposite two surfaces of the positive electrode current collector, the composition or parameters of the positive electrode material layer on any one of the surfaces meet the present disclosure, and are considered to fall within the protection scope of the present disclosure.

[0141] The present disclosure provides a lithium ion battery, comprising the positive electrode sheet of the preceding embodiments, further comprising a negative electrode sheet, an electrolyte, and a separator.

[0142] [Negative electrode sheet]

[0143] The negative electrode sheet of the present disclosure comprises a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0144] As an example, the negative electrode current collector has two opposite surfaces in the thickness direction of itself, and the negative electrode film layer is laminated on either one or both of the two opposite surfaces of the negative electrode current collector.

[0145] The negative electrode current collector can be made of a material with good electrical conductivity and mechanical strength, and serves as a conductor and a current collector. In some embodiments, the negative electrode current collector can be made of a copper foil.

[0146] In the negative electrode sheet of the present disclosure, the negative electrode film layer generally comprises a negative electrode active material and a binder, a conductive agent, and other optional additives. It is generally formed by coating a negative electrode slurry on a negative electrode current collector, drying, and cold pressing. The negative electrode slurry is generally formed by dispersing a negative electrode active material and a conductive agent, a binder, and optional additives in a solvent and stirring uniformly. The solvent can be N-methyl pyrrolidone (NMP) or deionized water.

[0147] In some embodiments, the negative electrode active material can include one or more of artificial graphite, natural graphite, silicon-based materials, and tin-based materials. Alternatively, the negative electrode active material includes one or more of artificial graphite and natural graphite. Alternatively, the negative electrode active material includes artificial graphite.

[0148] In some embodiments, the conductive agent can include one or more of super-conductive carbon, carbon black (e.g., Super P, acetylene black, Ketjen black, etc.), carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0149] In some embodiments, the binder can include one or more of styrene-butadiene rubber (SBR), water-based acrylic resin, polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl chitosan (CMCS).

[0150] In some embodiments, other optional additives are, for example, thickening agents (e.g., sodium carboxymethyl cellulose CMC-Na), PTC thermistor materials, etc.

[0151] [Electrolyte]

[0152] The electrolyte serves to conduct ions between the positive electrode sheet and the negative electrode sheet. The present disclosure does not have specific limitations on the type of electrolyte, which can be selected as needed. For example, the electrolyte can be an electrolyte solution. The electrolyte solution comprises an electrolyte salt and a solvent.

[0153] In some embodiments, the electrolyte salt can be one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bisfluorosulfonylimide (LiFSI), lithium bis-trifluoromethanesulfonylimide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalate borate (LiDFOB), lithium bisoxalate borate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorodioxalate phosphate (LiDFOP), and lithium tetrafluorooxalate phosphate (LiTFOP).

[0154] In some embodiments, the solvent can be one or more of ethylene carbonate (EC), propylene carbonate (PC), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS), and diethyl sulfone (ESE).

[0155] In some embodiments, the electrolyte solution can also optionally include an additive. For example, the additive can include a negative electrode film-forming additive, a positive electrode film-forming additive, and an additive capable of improving certain properties of the battery, such as an additive capable of improving overcharge performance of the battery, an additive capable of improving high-temperature performance of the battery, an additive capable of improving low-temperature performance of the battery, and the like.

[0156] [Separator]

[0157] The separator is disposed between the positive electrode sheet and the negative electrode sheet and functions to separate the positive electrode sheet and the negative electrode sheet. The lithium ion battery of the present disclosure is not particularly limited in terms of the type of separator and any publicly known porous structure separator for a lithium ion battery can be used. For example, the separator can be one or more of a glass fiber film, a non-woven fabric film, a polyethylene film, a polypropylene film, a polyvinylidene fluoride film, and a multi-layer composite film including one or two or more of these.

[0158] The positive electrode sheet, the negative electrode sheet, and the separator can be made into an electrode assembly through a stacking process or a winding process, with the separator being disposed between the positive electrode sheet and the negative electrode sheet to function to separate the positive electrode sheet and the negative electrode sheet. The electrode assembly is placed in an outer package, electrolyte solution is injected, and the opening is sealed, thereby obtaining a lithium ion battery.

[0159] The outer package of the lithium ion battery is used to encapsulate the electrode assembly and the electrolyte. In some embodiments, the outer package of the lithium ion battery can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer package of the lithium ion battery can also be a soft package, such as a pouch soft package. The material of the soft package can be plastic, such as one or more of polypropylene (PP), polybutylene terephthalate (PBT), polybutylene succinate (PBS), etc.

[0160] The shape of the lithium ion battery is not particularly limited in the present disclosure, which can be cylindrical, square or any other shape.

[0161] In some embodiments, the lithium ion battery can be assembled into a battery module, and the number of lithium ion batteries contained in the battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module.

[0162] In some embodiments, the above-mentioned battery module can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.

[0163] The present disclosure provides an electrical device comprising the lithium ion battery of the preceding embodiments.

[0164] The present disclosure also provides an electrical device comprising at least one of the lithium ion battery, the battery module, or the battery pack of the present disclosure. The lithium ion battery, the battery module, or the battery pack can be used as a power source of the device, or as an energy storage unit of the device. The device can be, but is not limited to, a mobile device (such as a mobile phone, a notebook computer, etc.), an electric vehicle (such as a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship and a satellite, an energy storage system, etc. The device can select the lithium ion battery, the battery module, or the battery pack according to its use requirements.

[0165] The features and performances of the present disclosure are further described in detail below in combination with embodiments.

[0166] Embodiment 1

[0167] A method for preparing a lithium ion battery, comprising the following steps:

[0168] (1) preparing nanocrystals under high gravity conditions by using a co-precipitation method

[0169] Nickel sulfate, cobalt sulfate and manganese sulfate are weighed according to the molar ratio of nickel cobalt manganese of 80:10:10, dissolved in deionized water to obtain a mixed salt solution of nickel cobalt manganese with a total cation molar concentration of 2M, and then transferred to the first liquid tank of the spiral channel type rotating bed; a mixed aqueous solution with a sodium hydroxide concentration of 4M and an ammonia concentration of 2M is transferred to the second liquid tank; 100mL of ammonia water with pH=10.5 is pre-added to the reactor as a reaction base solution; the rotating speed of the rotating bed is adjusted to 1200rpm; the solution in the first liquid tank is pumped into the rotating bed reactor at a speed of 80mL / min; the solution in the second liquid tank is pumped into the rotating bed reactor to maintain the pH at 11; a centrifugal pump is started to circulate the mixed solution in the supergravity device; when D50 reaches 350nm, the solution in the first liquid tank and the second liquid tank stops flowing and the rotating bed stops rotating; the obtained precipitate is shown in SEM in Figure 1A, the precipitate has a small particle size; after standing and aging for 8h, a first reaction liquid containing crystal seeds is obtained, the SEM of the crystal seeds is shown in Figure 1B, the precipitate particles are aggregated into crystal seeds, and the particle size is increased.

[0170] (2) Preparation of ternary positive electrode material precursor

[0171] The first reaction liquid containing crystal seeds is transferred to a reaction kettle, the reaction temperature is adjusted to 80℃, and sulfuric acid is added to adjust the pH to 10; the mixed salt solution of nickel cobalt manganese and 0.03M aqueous solution of sodium lignosulfonate as a crystal form regulator are added to the reaction kettle at a uniform speed of 0.3mL / min by a metering pump; a mixed solution of sodium hydroxide and ammonia is added to control the ammonia concentration to 0.5mol / L, and the pH is maintained at 10; stirring is carried out at a rotating speed of 500rpm; when D50 reaches 10μm, the feeding is stopped; after standing for 12h, a ternary positive electrode material precursor slurry is obtained. The ternary positive electrode material precursor slurry is pressure filtered, then washed with hot lye and pure water in sequence, and further dried, sieved and demagnetized to obtain a ternary positive electrode material precursor Ni 0.8 Co 0.1 Mn 0.1 (OH)2, the appearance and cross-sectional view are shown in Figures 1C and 1D respectively, a ternary positive electrode material precursor with good sphericity, relatively dense inside and loose outer layer is obtained, wherein the temperature of the hot lye is 60℃, the concentration is 60g / L, the alkali is sodium hydroxide, and the drying conditions are 130℃ and 5h.

[0172] (3) Preparation of ternary positive electrode material

[0173] The precursor material and lithium hydroxide are dosed according to a Li / (Ni+Co+Mn) molar ratio of 1.05:1, mixed uniformly in a high-speed mixer to obtain a mixed powder; the mixed powder is placed in a tube furnace for calcination under an oxygen atmosphere, during the calcination process, first heated to 500℃ at a rate of 2℃ / min and kept for 5h, then heated to 780℃ at a rate of 2℃ / min and kept for 12h, and finally naturally cooled to obtain a black powder ternary positive electrode material, the appearance and cross-sectional view are shown in Figures 1E and 1F respectively, as can be seen from the figures, the ternary positive electrode material has a relatively dense structure and fewer pores, and the cross-section of the ternary positive electrode material after 100 cycles at 1C is shown in Figure 2A, only some particles have small cracks, and the stability is good.

[0174] (4) Electrode preparation: ternary positive electrode material, conductive carbon black and PVDF are weighed according to a mass ratio of 8:1:1, ground thoroughly and put into a bottle, an appropriate amount of NMP solvent is added, and stirred on a stirrer for 24h to form a uniform slurry. The prepared slurry is uniformly coated on a clean aluminum foil using a wet film preparation device, and the loading amount is controlled to be 2.5±0.05mg / cm 2 Then it is placed in a 100℃ vacuum drying oven for drying for 24h. Then the positive electrode sheet is placed on an oil press to roll the positive electrode sheet at a pressure of 6MPa.

[0175] (5) Assembling of the coin cell: the prepared positive electrode sheet of the ternary positive electrode material is further punched into a circular positive electrode sheet with a diameter of 12mm, then a metal lithium disc is used as the negative electrode, Celgard2300 is used as the separator, 1M LiPF6 solution (solvent is a mixed solvent of EMC, DC and DMC in a volume ratio of 1:1:1) is used as the electrolyte, and a CR2032 type coin cell is assembled.

[0176] Example 2

[0177] A preparation method of a lithium ion battery, comprising the following steps:

[0178] (1) Nanocrystalline seeds are prepared by a coprecipitation method under high gravity conditions

[0179] Nickel sulfate, cobalt sulfate and manganese sulfate are weighed according to the molar ratio of nickel cobalt manganese of 80:10:10, dissolved in deionized water to obtain a mixed salt solution of nickel cobalt manganese with a total cation molar concentration of 2M, and then transferred to the first liquid tank of the spiral channel type rotating bed; a mixed aqueous solution with a sodium hydroxide concentration of 4M and an ammonia concentration of 2M is configured and transferred to the second liquid tank; 100mL of ammonia water with pH=10.5 is used as the reaction base solution and pre-added to the reactor; the rotating speed of the rotating bed is adjusted to 1000rpm; the solution in the first liquid tank is pumped into the rotating bed reactor at a speed of 50mL / min; the solution in the second liquid tank is pumped into the rotating bed reactor to control the pH at 11; a centrifugal pump is started to circulate the mixed solution in the supergravity device; when D50 reaches 220nm, the solution in the first liquid tank and the second liquid tank stops flowing and the rotating bed stops rotating; and the first reaction liquid containing crystal seeds is obtained after standing and aging for 12h.

[0180] Steps (2)-(5) are the same as in Example 1.

[0181] Example 3

[0182] A preparation method of a lithium ion battery, comprising the following steps:

[0183] (1) Under the condition of supergravity, nanocrystals are prepared by a coprecipitation method

[0184] Nickel sulfate, cobalt sulfate and manganese sulfate are weighed according to the molar ratio of nickel cobalt manganese of 80:10:10, dissolved in deionized water to obtain a mixed salt solution of nickel cobalt manganese with a total cation molar concentration of 2M, and then transferred to the first liquid tank of the spiral channel type rotating bed; a mixed aqueous solution with a sodium hydroxide concentration of 4M and an ammonia concentration of 2M is configured and transferred to the second liquid tank; 100mL of ammonia water with pH=10.5 is used as the reaction base solution and pre-added to the reactor; the rotating speed of the rotating bed is adjusted to 1000rpm; the solution in the first liquid tank is pumped into the rotating bed reactor at a speed of 50mL / min; the solution in the second liquid tank is pumped into the rotating bed reactor to control the pH at 11; a centrifugal pump is started to circulate the mixed solution in the supergravity device; when D50 reaches 220nm, the solution in the first liquid tank and the second liquid tank stops flowing and the rotating bed stops rotating; and the first reaction liquid containing crystal seeds is obtained after standing and aging for 12h.

[0185] Steps (2)-(5) are the same as in Example 1.

[0186] Example 4

[0187] A preparation method of a lithium ion battery, which is different from Example 1 in that in step (2), a 0.03M sodium polyacrylate solution is used instead of a 0.03M sodium lignosulfonate solution as the aqueous solution of crystal form regulator.

[0188] Example 5

[0189] A preparation method of a lithium ion battery, different from example 1, in step (2), 0.05M sodium lignosulfonate solution is used instead of 0.03M sodium lignosulfonate as the aqueous solution of crystal form regulator.

[0190] Example 6

[0191] A preparation method of a lithium ion battery, different from example 1, in step (2), 0.01M sodium lignosulfonate solution is used instead of 0.03M sodium lignosulfonate as the aqueous solution of crystal form regulator.

[0192] Example 7

[0193] A preparation method of a lithium ion battery, different from example 1, in step (1), the molar ratio of nickel, cobalt and manganese is 50:30:20; in step (2), 0.01M sodium polyacrylate solution is used instead of 0.03M sodium lignosulfonate as the aqueous solution of crystal form regulator, the flow rate is changed from 0.3mL / min to 0.2mL / min, and the ammonia concentration is controlled at 0.8M, to obtain ternary positive electrode material precursor Ni 0.5 Co 0.3 Mn 0.2 (OH)2.

[0194] Comparative example 1

[0195] A preparation method of a lithium ion battery, comprising the following steps:

[0196] (1) No crystal nucleus is prepared by using high gravity co-precipitation method.

[0197] 100mL of ammonia water with pH=10.5 is added to the reaction kettle as the reaction base solution, 2M nickel-cobalt-manganese mixed salt solution and 0.4M ammonia water are added to the reaction kettle by metering pump at the same time in the form of co-current, the flow rate of nickel-cobalt-manganese mixed salt solution is 80mL / min, sodium hydroxide solution is added at the same time to control the pH value of the reaction solution to 11, the ammonia concentration in the reaction solution is controlled at 0.4mol / L, the stirring speed is controlled at 300rpm, and the temperature of the reaction kettle is controlled at 50℃; the reaction kettle is replaced with inert atmosphere before feeding, the reaction process is monitored in real time, when the D50 of the material reaches 1μm, the reaction kettle stops feeding, and after the reaction is completed, the reaction kettle is aged for 15h to obtain the crystal seed.

[0198] Steps (2)-(5) are the same as example 1, wherein the cross-sectional view of the ternary positive electrode material precursor is shown in Figure 3, there are more pores in the inner and outer layers of the ternary positive electrode material precursor, the effective specific pore volume is reduced, and the impurity content is higher.

[0199] Comparative Example 2

[0200] A preparation method of a lithium ion battery, which is different from Example 1 in that sodium dodecyl benzene sulfonate is used instead of sodium lignosulfonate as a crystal form regulator.

[0201] Comparative Example 3

[0202] A preparation method of a lithium ion battery, comprising: weighing metal sulfate according to a molar ratio of Ni:Co:Mn=0.8:0.1:0.1, and preparing a mixed salt solution with a total concentration of 2M by using deionized water, then preparing a mixed alkali solution with a NaOH concentration of 0.2M by using deionized water to mix NaOH and ammonia according to a molar ratio of 3:1, and adding sodium dodecyl benzene sulfonate according to a mass ratio of NaOH to surfactant of 9:1 in the mixed alkali solution. 100mL of ammonia water with a pH of 11 is added to the reaction kettle as a reaction base solution. The stirring speed is set to 600rpm, and the reaction temperature is set to 50℃. The mixed salt solution and the mixed alkali solution are slowly and uniformly pumped into the reaction kettle, wherein the flow rate of the nickel-cobalt-manganese mixed salt solution is 80mL / min, the pH is kept stable at 11, the reaction kettle is replaced with an inert atmosphere before feeding, the reaction process is monitored in real time, the feeding is stopped when D50 reaches 6μm, and the ternary positive electrode material precursor slurry is aged for 15h. The ternary positive electrode material precursor Ni 0.8 Co 0.1 Mn 0.1 (OH)2.

[0203] Steps (3)-(5) are the same as Example 1.

[0204] Comparative Example 4

[0205] A preparation method of a lithium ion battery, comprising the following steps:

[0206] (1) Under the condition of high gravity, nano-crystalline seeds are prepared by a co-precipitation method

[0207] Nickel sulfate, cobalt sulfate, and manganese sulfate are weighed and dissolved in deionized water to obtain a mixed nickel-cobalt-manganese salt solution with a total cation molar concentration of 2M, which is then transferred to the first liquid holding tank of the spiral channel type rotating bed. A mixed aqueous solution of sodium hydroxide and ammonia with concentrations of 4M and 2M, respectively, is transferred to the second liquid holding tank. 100mL of ammonia water with pH=10.5 is used as the reaction base solution and is pre-added to the reactor. The rotating speed of the rotating bed is adjusted to 1800rpm. The solution in the first liquid holding tank is pumped into the rotating bed reactor at a speed of 120mL / min. The solution in the second liquid holding tank is pumped into the rotating bed reactor to maintain the pH at 10.5. At the same time, a centrifugal pump is started to circulate the mixed solution in the supergravity device. When D50 reaches 180nm, the solution in the first and second liquid holding tanks stops flowing and the rotating bed stops rotating. After 12h of standing and aging, a first reaction liquid containing crystal seeds is obtained.

[0208] The molar ratio of nickel, cobalt, and manganese is 80:10:10.

[0209] (2) Preparation of ternary positive electrode material precursor

[0210] The first reaction liquid containing crystal seeds is transferred to a reaction kettle, and the reaction temperature is adjusted to 80℃. Sulfuric acid is added to adjust the pH to 10. The mixed salt solution of nickel, cobalt, and manganese and the aqueous solution of crystal form regulator (0.06M aqueous solution of sodium lignosulfonate) are added to the reaction kettle at a uniform speed of 0.3mL / min by a metering pump. A mixed solution of sodium hydroxide and ammonia is added to control the ammonia concentration to 0.5mol / L, and the pH is maintained at 10. The rotating speed is 500rpm. When D50 reaches 10μm, the feeding is stopped. After 12h of standing and aging, a ternary positive electrode material precursor slurry is obtained. The ternary positive electrode material precursor slurry is pressure filtered, then washed with hot alkali solution, pure water, further dried, sieved, and de-magnetized to obtain a ternary positive electrode material precursor Ni 0.8 Co 0.1 Mn 0.1 (OH)2, wherein the temperature of the hot alkali solution is 60℃, the concentration is 60g / L, the alkali is sodium hydroxide, and the drying conditions are 130℃ for 5h.

[0211] Steps (3)-(5) are the same as in Example 1. After 100 cycles at 1C, the cross-section of the ternary positive electrode material is shown in FIG. 2B. The positive electrode material particle cracks increase significantly, and part of the positive electrode material particles are broken. Compared with Example 1, the cycle stability is significantly reduced.

[0212] Comparative Example 5

[0213] A preparation method of a lithium ion battery, comprising the following steps:

[0214] (1) Under supergravity conditions, a nano crystal seed is prepared by a co-precipitation method

[0215] Nickel sulfate, cobalt sulfate and manganese sulfate were weighed according to the molar ratio of nickel cobalt manganese of 80:10:10, dissolved in deionized water to obtain a nickel cobalt manganese mixed salt solution with a total cation molar concentration of 2M, and then transferred to the first liquid holding tank of the spiral channel type rotating bed. A mixed aqueous solution with a sodium hydroxide concentration of 4M and an ammonia concentration of 2M was transferred to the second liquid holding tank. 100mL of ammonia water with pH=10.5 was used as the reaction base liquid and was pre-added to the reactor. The rotating speed of the rotating bed was adjusted to 1000rpm. The solution in the first liquid holding tank was pumped into the rotating bed reactor at a speed of 120mL / min. The solution in the second liquid holding tank was pumped into the rotating bed reactor to maintain the pH at 10.5. At the same time, the centrifugal pump was started to circulate the mixed liquid in the supergravity device. When D50 reached 418nm, the solution in the first liquid holding tank and the second liquid holding tank stopped flowing, and the rotating bed stopped rotating. After standing and aging for 12h, a first reaction liquid containing crystal seeds was obtained.

[0216] (2) Preparation of ternary positive electrode material precursor

[0217] The first reaction liquid containing crystal seeds was transferred to a reaction kettle, and the reaction temperature was adjusted to 80℃. Sulfuric acid was added to adjust the pH to 10. The nickel cobalt manganese mixed salt solution was continuously added to the reaction kettle at a constant speed by a metering pump in a co-current manner. A mixed solution of sodium hydroxide and ammonia was added to control the ammonia concentration to 0.8mol / L, and the pH was maintained at 10. The rotating speed was 500rpm. When D50 reached 10μm, the feeding was stopped. After standing and aging for 12h, a ternary positive electrode material precursor slurry was obtained. The ternary positive electrode material precursor slurry was pressure filtered, then washed with hot lye, pure water, further dried, sieved and demagnetized to obtain a ternary positive electrode material precursor Ni 0.8 Co 0.1 Mn 0.1 (OH)2, wherein the temperature of the hot lye is 60℃, the concentration is 60g / L, the base is sodium hydroxide, and the drying conditions are 130℃ and 5h.

[0218] Steps (3)-(5) are the same as in Example 1, wherein the sphericity of the ternary positive electrode material precursor obtained is low, and the SEM is shown in Figure 4.

[0219] The performance of the ternary positive electrode material precursors obtained in the above examples and comparative examples was tested, and the test results are shown in Table 1. The performance of the ternary positive electrode materials obtained in some of the above examples and comparative examples was tested, and the test results are shown in Table 2. The specific test methods are as follows:

[0220] (1) A JEOL JSM-6490LV type scanning electron microscope was used to observe the overall and cross-sectional microstructure of the sample to be tested.

[0221] (2) The effective specific pore volume is determined by the following method.

[0222] V 总 The test method is as follows: the liquid level of mercury in a container filled with mercury is measured and recorded as H0, and the sample to be tested is placed in the container filled with mercury. Since the density of the sample to be tested is less than that of mercury, the material will float on the liquid surface. A piston with a volume V' is used to press the sample floating on the liquid surface below the liquid surface at a speed of less than 50 mm / min. After the liquid surface is static, the liquid level is measured and recorded as H1. According to H0 and H1 and other shape parameters of the container, the volumes corresponding to the liquid levels H0 and H1 can be calculated as V0 and V1, respectively. Thus, V 总 can be calculated as V 总 1-V0-V'.

[0223] V 排 The test method is as follows: the volume V0 of pure water is read, and the sample to be tested is placed in a graduated cylinder containing 25℃ deionized water. After the sample to be tested sinks to the bottom, it is ultrasonically treated for 5 min and then the volume V1 is read. V 排 can be calculated as V 材 1-V0.

[0224] V 材 The test method is as follows: the density of the sample to be tested is tested by the drainage method. The density of the nickel-cobalt-manganese hydroxide is in the range of 3.4-3.8 g / cm 3 , i.e. the V 材 of the ternary positive electrode material precursor is in the range of 0.263-0.294 cm 3 / g; the density of the nickel-cobalt-manganese lithium acid single crystal is in the range of 2.5-2.8 g / cm 3 , i.e. the V 材 of the ternary positive electrode material is in the range of 0.357-0.400 cm 3 / g.

[0225] The effective specific pore volume is calculated according to the formula: (V 总 -V 排 ) / (V 总 -V 材 ) x 100%.

[0226] (3) Particle size: tested by MS3000 laser particle size analyzer.

[0227] (4) BET specific surface area

[0228] The specific surface area of the sample to be tested is obtained by analyzing the data of nitrogen adsorption-desorption curves at medium-low pressure stage by BET formula. The test is carried out on Autosorb IQ2 full-automatic specific surface area pore size analyzer produced by Anton Paar Instruments Company, Austria.

[0229] (5) Chemical composition analysis, PEAvio200 inductively coupled plasma optical emission spectrometry (ICP-OES) was used for testing.

[0230] (6) Tap density, according to GB / T 21354-2008 General Method for Determination of Tap Density of Powder Products.

[0231] (7) Electrochemical performance: LANHE CT2001A battery test system was used for rate performance test, and the test conditions were as follows: temperature was 25℃, voltage range was 3-4.5V, and 1C=180mA / g.

[0232] Table 1 Test results of ternary positive electrode material precursor

[0233] Adjusting the preparation methods and reaction parameters of steps (1) and (2) can control the effective specific pore volume of the spherical ternary positive electrode material precursor, and further affect the tap density and electrochemical performance of the material. Specifically, the more compact the crystal seed structure obtained in step (1) and the smaller the particle size, the higher the effective specific pore volume of the obtained precursor; in step (2), the polyanion surfactant has a better crystal type adjusting effect than the small molecule surfactant, that is, the effective specific pore volume of the obtained precursor is higher, because the steric hindrance effect provided by sodium lignosulfonate is more obvious; according to the comparison of examples 1, 5 and 6, under the condition that other conditions are the same, the higher the concentration of the crystal type adjusting agent, the higher the effective specific pore volume of the precursor, and the less the residual amount of impurity elements in the material.

[0234] Table 2 Test results of ternary positive electrode material

[0235] Comparing example 1 and comparative example 2, the specific surface area of comparative example 2 is higher, but the rate performance is lower. Generally, the larger the specific surface area, the larger the contact area of lithium ions and electrolyte, and the higher the lithium ion transmission efficiency. The reason for this result is that although comparative example 2 has a higher specific surface area, it uses a small molecule as a crystal type adjusting agent, and the steric hindrance effect is too small compared with a macromolecular crystal type adjusting agent, so that the number of micropores on the surface of the ternary positive electrode material prepared is larger, but the wettability of the micropores to the electrolyte is not as good as that of mesopores or macropores, so the effective contact area with the electrolyte is smaller, and thus the rate performance is not as good as that of example 1.

[0236] The ternary positive electrode material obtained in Comparative Example 1 and Example 4 have similar tap densities, but the effective specific pore volume of Example 1 is better, and thus has higher rate performance; first, the similar tap densities show that the internal compactness of the ternary positive electrode material is similar, the difference is that the volume of the pores in the open pores of the ternary positive electrode material that can be infiltrated by the electrolyte is inconsistent, because the smaller the pore size, the lower the wettability of the pores due to liquid tension, that is, the number of micropores of the ternary positive electrode material in Example 4 is more and the number of mesopores or macropores of the ternary positive electrode material in Example 1 is more, so the lithium ion transmission efficiency of the ternary positive electrode material prepared in Example 1 is higher, and thus has better rate performance. Industrial applicability

[0237] The effective specific pore volume of the ternary positive electrode material precursor prepared by the present disclosure is 75% to 90%, which is beneficial to reduce the residual amount of impurities in the precursor; when the positive electrode material is prepared by using the same, it is beneficial for lithium to enter the inside of the material, thereby forming a positive electrode material with complete crystal and uniform element distribution, and the positive electrode material prepared therefrom has better cycle stability and rate performance.

Claims

A ternary positive electrode material precursor, characterized in that, Ni a Co b M 1-a-b (OH)2, wherein 0.3≤a<0.98, 0 The ternary positive electrode material precursor comprises effective pores and ineffective pores, the effective pores refer to pores into which water can enter under standard atmospheric pressure, the ineffective pores refer to pores into which water cannot enter under standard atmospheric pressure, and the effective specific pore volume of the ternary positive electrode material precursor is 75% to 90%. wherein the effective specific pore volume = V 有效 / V 孔 × 100%, V 有效 refers to the specific pore volume of effective pores, in cm 3 / g, V 无效 refers to the specific pore volume of ineffective pores, in cm 3 / g; V 孔 = V 有效 + V 无效 . The ternary cathode material precursor according to claim 1, characterized in that, The ternary positive electrode material precursor satisfies at least one of the following ①-⑥: 孔 0.01 cm 3 0.06 cm 3 / g;​ V 有效 = V 总 - V 排 , V 孔 = V 总 - V 材 ; wherein, V 总 = V 材 + V 有效 + V 无效 , refers to the volume of mercury displaced by per unit mass of ternary cathode material precursor immersed in mercury, unit cm 3 / g; V 排 = V 材 + V 无效 , refers to the volume of water displaced by per unit mass of ternary cathode material precursor immersed in water, unit cm 3 / g; V 材 is the reciprocal of the density of the ternary cathode material precursor; iii. said V 有效 and V 孔 The test procedures were all carried out at a temperature of 4°C to 80°C. ④The D50 of the ternary positive electrode material precursor is 8-12 μm; 5. The specific surface area of the ternary positive electrode material precursor is 6.4 m 2 / g~7.5 m 2 / g; ⑥The tap density of the ternary positive electrode material precursor is 1.9g / cm 3 ~2.3g / cm 3 . The ternary positive electrode material precursor according to claim 1 or 2, characterized in that, The total weight percentage of sodium and sulfur in the ternary positive electrode material precursor is less than 0.21 wt%; And / or, the weight percentage of sodium in the ternary positive electrode material precursor is less than 0.03 wt%; And / or, the weight percentage of sulfur in the ternary positive electrode material precursor is less than 0.21 wt%. A preparation method of the ternary positive electrode material precursor according to any one of claims 1-3, characterized in that, It comprises: Seed preparation, under the condition of high gravity, nano-crystal seeds of ternary positive electrode material precursor are prepared by co-precipitation method; Seed growth, the nano-crystal seeds are grown to obtain the ternary positive electrode material precursor. The preparation method of the ternary cathode material precursor according to claim 4, characterized in that, The seed preparation step comprises: taking ammonia water with pH of 10-11 as a reaction base solution, placing nickel-cobalt M mixed salt solution and mixed aqueous solution containing precipitant and complexing agent in two liquid holding tanks of a rotating bed reactor, and adding them into the rotating bed reactor, so that the pH value is maintained at 10.5-11.5, until the precipitation reaches the first preset particle size, the feeding is stopped and the rotating bed stops rotating, and the first reaction liquid containing seeds is obtained after standing and aging, the seed preparation step further satisfies at least one of the following A-I: A. The D50 of the first preset particle size is 200-500 nm; B. In the mixed aqueous solution, the concentration of the precipitant is 3-5 mol / L, and the concentration of the complexing agent is 1.5-2.5 mol / L; C. The rotating speed of the rotating bed is 1000-1500 rpm; D. The salt in the nickel-cobalt M mixed salt solution is one of nitrate, hydrochloride or sulfate; E. The molar ratio of nickel-cobalt M is 35-98:1-35:1-35; F. The total concentration of nickel, cobalt and M in the nickel-cobalt M mixed salt solution is 1.5-2.5 mol / L; G. The flow rate of the nickel-cobalt M mixed salt solution is 50-100 mL / min; H. The precipitant is potassium hydroxide or sodium hydroxide; I. The complexing agent is one of ammonia water, ammonium nitrate, ammonium sulfate and ammonium chloride. The preparation method of the ternary positive electrode material precursor according to claim 4 or 5, characterized in that, The seed growth step comprises: adjusting the pH of the first reaction liquid containing seeds to 9.5-10.5, then adding the nickel-cobalt M mixed salt solution, aqueous solution of crystal type regulator and mixed aqueous solution containing precipitant and complexing agent into the first reaction liquid containing seeds, obtaining the second reaction liquid and keeping the pH of the second reaction liquid at 9.5-10.5 and the ammonia concentration at 0.4-0.8 mol / L, until the precipitation reaches the second preset particle size, the feeding is stopped, and the slurry containing the ternary positive electrode material precursor is obtained after standing and aging, the seed growth step further satisfies at least one of the following a-f: a. The crystal type regulator is an anionic surfactant; b. The concentration of the aqueous solution of the crystal type regulator is 0.01-0.05 mol / L; c. The flow rate of the nickel-cobalt M mixed salt solution is 0.2-0.5 mL / min; d. the flow rate of the aqueous solution of the crystal form regulator is 0.2 mL / min to 0.5 mL / min; e. the D50 of the second preset particle size is 8 μm to 12 μm; f. further comprising solid-liquid separation of the slurry containing the ternary positive electrode material precursor, and then sequentially using alkali liquor and pure water to wash, dry, sieve and remove magnetism from the solid phase to obtain the ternary positive electrode material precursor. The preparation method of the ternary cathode material precursor according to claim 6, characterized in that, The crystal form regulator is sodium polyacrylate and sodium lignosulfonate. And / or, the alkali liquor is sodium hydroxide solution or potassium hydroxide solution, the concentration is 50 g / L to 70 g / L, and the temperature is 50°C to 80°C. A ternary positive electrode material is characterized in that, The ternary positive electrode material is obtained by mixing the ternary positive electrode material precursor of any one of claims 1-3 or the ternary positive electrode material precursor prepared by the preparation method of any one of claims 4-7 with a lithium source and calcining, and the ternary positive electrode material further satisfies at least one of g-i: g. the effective specific pore volume of the ternary positive electrode material is 75% to 90%; h. the specific surface area of the ternary positive electrode material is 0.4 m 2 / g ~ 0.7 m 2 / g; i. the tap density of the ternary cathode material is 2.6 g / cm 3 ~ 2.9 g / cm 3 . The ternary cathode material according to claim 8, characterized in that, The first discharge specific capacity of the ternary positive electrode material corresponding to 0.1C is 192 mAh / g to 208 mAh / g; And / or, the first discharge specific capacity of the ternary positive electrode material corresponding to 1C is 167 mAh / g to 190 mAh / g; And / or, the capacity retention rate of the ternary positive electrode material corresponding to 1C after 100 cycles is 85% to 97%; And / or, the first discharge specific capacity of the ternary positive electrode material corresponding to 5C is 142 mAh / g to 165 mAh / g. A method for producing the ternary positive electrode material according to claim 8 or 9, characterized in that The ternary positive electrode material is obtained by mixing the ternary positive electrode material precursor of any one of claims 1-3 or the ternary positive electrode material precursor prepared by the preparation method of any one of claims 4-7 with a lithium source and calcining. The preparation method of the ternary positive electrode material according to claim 10, characterized in that, The calcination temperature is 400°C to 800°C, and the calcination time is 15 h to 20 h. The preparation method of the ternary positive electrode material according to claim 10 or 11, characterized in that, The calcination includes one-stage calcination and two-stage calcination, wherein the one-stage calcination temperature is 400°C to 600°C, and the time is 4 h to 6 h; the two-stage calcination temperature is 750°C to 800°C, and the time is 10 h to 14 h. The preparation method of the ternary positive electrode material according to any one of claims 10-12, characterized in that, The temperature rising rate in the calcination step is 1.5°C / min to 2.5°C / min. A positive electrode sheet characterized by The positive electrode material of claim 8 or 9. A single cell characterized in that The monomer battery contains the positive electrode sheet of claim 14. A lithium-ion battery, characterized in that The positive electrode sheet of claim 14. An electrical device, characterized in that The lithium ion battery of claim 16.

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