CN114275825B - Precursor, preparation method, positive electrode material comprising precursor, positive electrode and battery - Google Patents
Precursor, preparation method, positive electrode material comprising precursor, positive electrode and battery Download PDFInfo
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- 239000002243 precursor Substances 0.000 title claims abstract description 178
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 45
- 238000002360 preparation method Methods 0.000 title claims abstract description 22
- -1 preparation method Substances 0.000 title description 2
- 239000011164 primary particle Substances 0.000 claims abstract description 29
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 21
- 239000012798 spherical particle Substances 0.000 claims abstract description 15
- 238000000975 co-precipitation Methods 0.000 claims description 95
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 78
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 70
- 239000012266 salt solution Substances 0.000 claims description 52
- 239000002002 slurry Substances 0.000 claims description 49
- 239000011572 manganese Substances 0.000 claims description 40
- 238000000034 method Methods 0.000 claims description 39
- 238000003756 stirring Methods 0.000 claims description 34
- 239000000243 solution Substances 0.000 claims description 33
- 238000001354 calcination Methods 0.000 claims description 30
- 229910052759 nickel Inorganic materials 0.000 claims description 27
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 24
- 229910052748 manganese Inorganic materials 0.000 claims description 24
- 150000003839 salts Chemical class 0.000 claims description 19
- 229910017052 cobalt Inorganic materials 0.000 claims description 15
- 239000010941 cobalt Substances 0.000 claims description 15
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 15
- 239000008139 complexing agent Substances 0.000 claims description 15
- 230000032683 aging Effects 0.000 claims description 13
- 150000001413 amino acids Chemical class 0.000 claims description 12
- 238000000926 separation method Methods 0.000 claims description 12
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 11
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 8
- 229940099596 manganese sulfate Drugs 0.000 claims description 8
- 239000011702 manganese sulphate Substances 0.000 claims description 8
- 235000007079 manganese sulphate Nutrition 0.000 claims description 8
- SQQMAOCOWKFBNP-UHFFFAOYSA-L manganese(II) sulfate Chemical compound [Mn+2].[O-]S([O-])(=O)=O SQQMAOCOWKFBNP-UHFFFAOYSA-L 0.000 claims description 8
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 claims description 8
- 229940053662 nickel sulfate Drugs 0.000 claims description 8
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 claims description 8
- 229940044175 cobalt sulfate Drugs 0.000 claims description 4
- 229910000361 cobalt sulfate Inorganic materials 0.000 claims description 4
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical compound [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 239000004475 Arginine Substances 0.000 claims description 3
- 239000004472 Lysine Substances 0.000 claims description 3
- KDXKERNSBIXSRK-UHFFFAOYSA-N Lysine Natural products NCCCCC(N)C(O)=O KDXKERNSBIXSRK-UHFFFAOYSA-N 0.000 claims description 3
- ODKSFYDXXFIFQN-UHFFFAOYSA-N arginine Natural products OC(=O)C(N)CCCNC(N)=N ODKSFYDXXFIFQN-UHFFFAOYSA-N 0.000 claims description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 3
- LNOPIUAQISRISI-UHFFFAOYSA-N n'-hydroxy-2-propan-2-ylsulfonylethanimidamide Chemical compound CC(C)S(=O)(=O)CC(N)=NO LNOPIUAQISRISI-UHFFFAOYSA-N 0.000 claims description 3
- 229920001184 polypeptide Polymers 0.000 claims description 3
- 102000004196 processed proteins & peptides Human genes 0.000 claims description 3
- 108090000765 processed proteins & peptides Proteins 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims 1
- ZAUUZASCMSWKGX-UHFFFAOYSA-N manganese nickel Chemical compound [Mn].[Ni] ZAUUZASCMSWKGX-UHFFFAOYSA-N 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 28
- 239000000463 material Substances 0.000 abstract description 27
- 238000007086 side reaction Methods 0.000 abstract description 14
- 238000010298 pulverizing process Methods 0.000 abstract description 11
- 238000009792 diffusion process Methods 0.000 abstract description 6
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 30
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 22
- 230000001276 controlling effect Effects 0.000 description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 229910021529 ammonia Inorganic materials 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 9
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- 238000005245 sintering Methods 0.000 description 8
- 239000007787 solid Substances 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
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- 230000001105 regulatory effect Effects 0.000 description 4
- KFDQGLPGKXUTMZ-UHFFFAOYSA-N [Mn].[Co].[Ni] Chemical compound [Mn].[Co].[Ni] KFDQGLPGKXUTMZ-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
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- 238000007599 discharging Methods 0.000 description 2
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- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
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- 239000010406 cathode material Substances 0.000 description 1
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- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Battery Electrode And Active Subsutance (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
The invention provides a precursor, a preparation method, a positive electrode material comprising the precursor, a positive electrode and a battery. The precursor is a binary precursor or a ternary precursor, the precursor comprises spherical particles, the spherical particles are flaky petal-shaped primary particles, the flaky petal-shaped primary particles have the width of 1-2 mu m, and the specific surface area of the precursor is 4-10 m 2 And/g. The spherical particles of the precursor have flaky petal-shaped primary particles, and the flaky petal-shaped morphology can increase the diffusion channel of lithium ions; the combination mode of the flaky petal-shaped primary particles in the precursor can influence the specific surface area and the strength of the material, but the specific surface area of the precursor is too large to easily cause the increase of side reaction, so the specific surface area of the precursor is controlled to control and adjust the combination mode of the flaky petal-shaped primary particles, and the aim of reducing the generation of the side reaction is fulfilled; the specific surface area is controlled, so that the strength of the material can be improved, and the crushing and pulverization of particles are inhibited; the assembled battery has good cycle performance.
Description
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a precursor, a preparation method, a positive electrode material comprising the precursor, a positive electrode and a battery.
Background
The lithium ion battery plays an important role in daily life, and the development of the new energy automobile industry brings new requirements to the lithium ion battery, so that the improvement of the energy density and the cycling stability of the lithium ion battery is urgent. The nickel-cobalt-manganese ternary material is a common positive electrode material at present, and the preparation process generally comprises the following steps: firstly, preparing a precursor; and secondly, sintering the precursor. The ternary material has higher theoretical specific capacity, but the cycle stability and the safety of the ternary material still need to be improved. The physical properties of the ternary material precursor have an important impact on the electrochemical properties of the ternary material.
The current preparation method of the precursor mainly adopts a coprecipitation method, and a soluble nickel-cobalt-manganese salt solution and a precipitant are utilized to react under the participation of a complexing agent to obtain precursor precipitate, wherein the precipitant mainly comprises the following components: soluble carbonate or hydroxide, and the complexing agent mainly comprises ammonia water, ammonium bicarbonate, and the like. Due to the technical problem of precursor coprecipitation, the precursor of the ternary material in the market at present has single appearance and is mostly spheroid polycrystalline particles. When primary particles on the surface of the crystal are finer, the specific surface area of the precursor is larger, the specific surface area of the ternary positive electrode material after sintering is generally larger, the specific surface area is larger, the contact area between the positive electrode material and electrolyte is larger, lithium ions are easier to be extracted from the inside of the material, and therefore the capacity of the material is higher. Meanwhile, as the contact area of the ternary material and the electrolyte is larger, the side reaction of the ternary material and the electrolyte is increased, the capacity retention rate of the ternary material is poorer, the gas production of the ternary material is more serious, and the safety performance is poorer; on the contrary, when the specific surface area of the precursor is smaller, the capacity of the ternary positive electrode material after sintering is lower, the capacity retention rate is higher, the gas production of the material is less, and the safety performance is higher.
Disclosure of Invention
The invention mainly aims to provide a precursor, a preparation method, a positive electrode material comprising the precursor, a positive electrode and a battery, so as to solve the problem that the cycle performance of the battery is poor due to the large specific surface area of the precursor in the prior art.
In order to achieve the above object, according to one aspect of the present invention, there is provided a positive electrode material precursor, the precursor being a binary precursor or a ternary precursor, the precursor comprising spherical particles having flaky flowersThe petal-shaped primary particles have the width of 1-2 mu m and the specific surface area of the precursor of 4-10 m 2 /g。
Further, the general formula of the binary precursor is Ni x Mn y (OH) 2 Wherein x is more than or equal to 0.5 and less than or equal to 0.8, y is more than or equal to 0.2 and less than or equal to 0.5, and x+y=1; preferred ternary precursors have the general formula Ni a Co b Mn c (OH) 2 Wherein a is more than or equal to 0.5 and less than or equal to 0.8,0 percent<b≤0.2，0.1≤c≤0.5，a+b+c＝1。
Further, D of the precursor 50 3-10 μm.
In order to achieve the above object, according to one aspect of the present invention, there is provided a method for preparing a positive electrode material precursor, the method comprising: step S1, under a first stirring condition, carrying out first coprecipitation treatment on a salt solution by adopting a precipitant, wherein the salt solution is a salt solution containing nickel and manganese or a salt solution containing nickel and cobalt and manganese, the pH value of the first coprecipitation treatment is 11-12, and the first stirring speed is 500-1000 rpm, so as to obtain first precursor slurry; s2, under a second stirring condition, carrying out second coprecipitation treatment on the first precursor slurry by adopting a precipitant, wherein the pH value of the second coprecipitation treatment is 11.3-13, the pH value of the second coprecipitation treatment is larger than that of the first coprecipitation treatment, preferably, the difference value between the pH value of the second coprecipitation treatment and that of the first coprecipitation treatment is 0.3-1, the speed of the second stirring is 100-500 rpm, preferably, the speed of the second stirring is smaller than that of the first stirring, and preferably, the speed of the second stirring is 50-80% of that of the first stirring, so as to obtain the second precursor slurry; and S3, carrying out solid-liquid separation and drying on the second precursor slurry to obtain the precursor of the positive electrode material.
Further, in step S1, the temperature of the first coprecipitation treatment is 40 to 80 ℃, preferably the temperature of the first coprecipitation treatment is 45 to 60 ℃, preferably the time of the first coprecipitation treatment is 30 to 50 hours, preferably the temperature of the second coprecipitation treatment is 50 to 80 ℃, preferably the time of the second coprecipitation treatment is 40 to 60 hours, preferably the temperature of the second coprecipitation treatment is greater than or equal to the temperature of the first coprecipitation treatment.
Further, the salt in the salt solution comprises two or three of nickel sulfate, cobalt sulfate and manganese sulfate; the total concentration of nickel and manganese elements in the salt solution containing nickel and manganese is 0.5-2 mol/L, and the molar ratio of nickel to manganese is 0.5-0.8: 0.2 to 0.5; the total molar concentration of nickel, cobalt and manganese elements in the salt solution containing nickel, cobalt and manganese is 0.5-2 mol/L, and the molar ratio of nickel, cobalt and manganese is 0.5-0.8: 0 to 0.2:0.1 to 0.5, and the cobalt content is not zero, preferably the salt concentration of the salt solution is 1 to 2mol/L.
Further, the precipitant includes sodium hydroxide and a complexing agent; preferably, the complexing agent is selected from one or more of ammonia water, amino acid, polypeptide and sulfamic acid; preferred amino acids include amino acids having an isoelectric point which is basic; more preferably the amino acid is lysine and/or arginine.
Further, it is preferable that the concentration of sodium hydroxide in the precipitant solution is 2 to 10mol/L, the concentration of sodium hydroxide is 2.5 to 5mol/L, the concentration of complexing agent is 0.02 to 2.0mol/L, the concentration of complexing agent is more preferably 0.05 to 1.5mol/L, and the concentration of complexing agent is more preferably 0.3 to 1.2mol/L.
Further, the preparation method further comprises the following steps: aging the second precursor slurry; preferably, the aging time is 0.5 to 5 hours.
Further, the preparation method further comprises the following steps: a demagnetizing step is added after the solution preparing step and after the aging step.
According to another aspect of the present invention, there is provided a positive electrode material, wherein the positive electrode material is prepared by calcining the precursor or the precursor prepared by the preparation method.
Further, the calcination includes a first calcination and a second calcination, preferably the first calcination is performed at a temperature of 450 to 600 ℃, preferably for a time of 4 to 6 hours; the second calcination is preferably carried out at a temperature of 700 to 850 ℃, and the second calcination is preferably carried out for a time of 15 to 25 hours.
According to still another aspect of the present invention, there is provided a positive electrode of a lithium ion battery, including a positive electrode current collector and a positive electrode material layer including the positive electrode material.
According to still another aspect of the present invention, there is provided a lithium ion battery comprising a positive electrode and a negative electrode, the positive electrode being the positive electrode described above.
By applying the technical scheme of the invention, the spherical particles of the precursor have flaky petal-shaped primary particles, the width of the flaky petal-shaped primary particles is 1-2 mu m, and the flaky petal-shaped morphology can increase the diffusion channel of lithium ions; the combination mode of the flaky petal-shaped primary particles in the precursor can influence the specific surface area and the strength of the material, but the specific surface area of the precursor is too large to easily cause the increase of side reaction, so the specific surface area of the precursor is controlled to be 4-10 m 2 And/g, the combination mode of flaky petal-shaped primary particles is controlled and regulated, so that the aim of reducing the generation of side reaction is fulfilled; the control of the specific surface area can also improve the strength of the material and inhibit the crushing and pulverization of particles; the assembled battery has good cycle performance.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:
FIG. 1 shows an SEM image of a precursor of example 1 of the invention;
fig. 2 shows a cycle performance graph of inventive example 1 and comparative example 1.
Detailed Description
It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate in order to describe the embodiments of the invention herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
As analyzed in the background of the present application, the prior art has a problem that the cycle performance of the battery is poor due to the large specific surface area of the precursor. To solve this problem, the present application provides a precursor, a preparation method, a positive electrode material including the same, a positive electrode, and a battery.
In an exemplary embodiment of the present application, there is provided a positive electrode material precursor, the positive electrode material precursor being a binary precursor or a ternary precursor, the precursor including spherical particles having flaky petal-shaped primary particles, the flaky petal-shaped primary particles having a width of 1 to 2 μm, the precursor having a specific surface area of 4 to 10m 2 Preferably 4.4 to 6.8 m/g 2 /g。
The width of the flaky petal shape is any dimension in the vertical and thickness directions.
The spherical particles of the precursor have flaky petal-shaped primary particles, the width of each flaky petal-shaped primary particle is 1-2 mu m, and the flaky petal-shaped morphology can increase the diffusion channel of lithium ions; the combination mode of the flaky petal-shaped primary particles in the precursor can influence the specific surface area and the strength of the material, but the specific surface area of the precursor is too large to easily cause the increase of side reaction, so the specific surface area of the precursor is controlled to be 4-10 m 2 And/g, the combination mode of flaky petal-shaped primary particles is controlled and regulated, so that the aim of reducing the generation of side reaction is fulfilled; the control of the specific surface area can also improve the strength of the material and inhibit the crushing and pulverization of particles; the assembled battery has good cycle performance.
In some embodiments, the binary precursor has the general formula Ni x Mn y (OH) 2 Wherein 0.5.ltoreq.x.ltoreq.0.8, 0.2.ltoreq.y.ltoreq.0.5, x+y=1, preferably 0.7.ltoreq.a.ltoreq.0.8, 0.2<b is less than or equal to 0.3; preferred ternary precursors have the general formula Ni a Co b Mn c (OH) 2 Wherein a is more than or equal to 0.5 and less than or equal to 0.8，0<b is equal to or less than 0.2,0.1 is equal to or less than c is equal to or less than 0.5, a+b+c=1, preferably 0.7 is equal to or less than a is equal to or less than 0.8,0.05<b is more than or equal to 0.1,0.1, c is more than or equal to 0.15. The precursor has a structural composition suitable for being applied to the binary precursor and the ternary precursor, and has more remarkable effect.
In some embodiments, D of the precursor 50 3 to 10. Mu.m, preferably 3.4 to 5.6. Mu.m, if the precursor has a particle size D 50 Controlling the particle size in this range can further reduce the specific surface area of the precursor, if particle size D 50 Too small results in too large a specific surface area of the precursor, which leads to increased side reactions and poor cycle performance of the assembled battery.
In another exemplary embodiment of the present application, there is provided a method for preparing a positive electrode material precursor, the method comprising: step S1, under a first stirring condition, carrying out first coprecipitation treatment on a salt solution by adopting a precipitant, wherein the salt solution is a salt solution containing nickel and manganese or a salt solution containing nickel and cobalt and manganese, the pH value of the first coprecipitation treatment is 11-12, and the first stirring speed is 500-1000 rpm, so as to obtain first precursor slurry; s2, carrying out second coprecipitation treatment on the first precursor slurry by adopting a precipitant under a second stirring condition, wherein the pH value of the second coprecipitation treatment is 11.3-13, the pH value of the second coprecipitation treatment is larger than that of the first coprecipitation treatment, the difference value between the pH value of the second coprecipitation treatment and that of the first coprecipitation treatment is 0.3-1, the speed of the second stirring is 100-500 rpm, the speed of the second stirring is preferably smaller than that of the first stirring, and the speed of the second stirring is preferably 50-80% of that of the first stirring; and S3, carrying out solid-liquid separation and drying on the second precursor slurry to obtain the positive electrode material precursor.
The preparation method adopts a two-step coprecipitation method to prepare the precursor, and the morphology of the precursor can be effectively controlled by adjusting reaction conditions such as rotating speed and pH value; this application first sediment adopts pH value 11~12 to control the size of precursor crystal nucleus, in the crystal nucleus growth process of precursor, pH can reduce gradually, and this application is big than the pH value of first coprecipitation at the pH value that the second coprecipitation adopted, especially when two difference is between 0.3~1, reduce the rotational speed simultaneously, the mesh of control precursor appearance can be reached in the synergism of two conditions, the degree of the flaky petal-shaped primary particle formation spherical granule of control, and guarantee to take shape effectually, thereby can reduce the specific surface area of precursor and improve its intensity.
The spherical particles of the precursor obtained by the preparation method have flaky petal-shaped primary particles, the width of each flaky petal-shaped primary particle is 1-2 mu m, and the flaky petal-shaped morphology can increase the diffusion channel of lithium ions; the combination mode of the flaky petal-shaped primary particles in the precursor can influence the specific surface area and the strength of the material, but the specific surface area of the precursor is too large to easily cause the increase of side reaction, so the specific surface area of the precursor is controlled to be 4-10 m 2 And/g, the combination mode of flaky petal-shaped primary particles is controlled and regulated, so that the aim of reducing the generation of side reaction is fulfilled; the control of the specific surface area can also improve the strength of the material and inhibit the crushing and pulverization of particles; the assembled battery has good cycle performance.
In order to control the precursor nucleus growth size, in some embodiments, in step S1, the temperature of the first coprecipitation treatment is 40 to 80 ℃, preferably the temperature of the first coprecipitation treatment is 45 to 60 ℃, preferably the time of the first coprecipitation treatment is 30 to 50 hours. In order to control the morphology of the precursor nuclei, in some embodiments, the temperature of the second coprecipitation process may be increased, for example, in step S2, preferably the temperature of the second coprecipitation process is 50 to 80 ℃, preferably the time of the second coprecipitation process is 40 to 60 hours, and preferably the temperature of the second coprecipitation process is not less than the temperature of the first coprecipitation process.
The above-mentioned salt solution is not particularly limited, and a salt solution conventional in the art may be used in the present invention, and in some embodiments, the salt in the salt solution includes two or three of nickel sulfate, cobalt sulfate, and manganese sulfate; the total concentration of nickel and manganese elements in the salt solution containing nickel and manganese is 0.5-2 mol/L, and the molar ratio of nickel to manganese is 0.5-0.8: 0.2 to 0.5, preferably 0.7 to 0.8:0.2 to 0.3; the total molar concentration of nickel, cobalt and manganese elements in the salt solution containing nickel, cobalt and manganese is 0.5-2 mol/L, and the molar ratio of nickel, cobalt and manganese is 0.5-0.8: 0 to 0.2:0.1 to 0.5, and the cobalt content is not zero, preferably 0.5 to 0.8:0.05 to 0.1: the salt concentration of the salt solution is preferably 1 to 2mol/L from 0.1 to 0.15. The salt concentration in the salt solution is favorable for controlling the formation speed of the petal-shaped precursor in the range, and the excessive salt concentration in the salt solution can cause the increase of the solid content of the reaction kettle to finally cause the overlarge specific surface area, and the excessively low salt concentration in the salt solution can cause the lower productivity and the waste of water resources.
The precipitants of the present invention may be conventional precipitants, and in some embodiments, include sodium hydroxide and complexing agents; preferably, the complexing agent is selected from one or more of ammonia water, amino acid, polypeptide and sulfamic acid; preferred amino acids include amino acids having an isoelectric point which is basic; more preferably the amino acid is lysine and/or arginine. In some embodiments, the precipitants of the present application are added in the form of a solution, in order to match the salt solution while adjusting the pH to avoid excessive dilution of the salt solution, in some embodiments, the concentration of sodium hydroxide in the precipitant solution is 2 to 10mol/L, preferably 2.5 to 5mol/L, preferably 0.02 to 2.0mol/L, more preferably 0.05 to 1.5mol/L, and even more preferably 0.3 to 1.2mol/L.
In order to further precisely control the precursor composition, in some embodiments, before performing step S2, the preparation method further includes separating a portion of the first precursor slurry, and performing a second co-precipitation treatment using the remaining portion of the first precursor slurry as a raw material in step S2, where the solid content in the separated portion of the first precursor slurry may be higher than that in the first precursor slurry, so that the solid content of the remaining first precursor slurry entering step S2 is reduced, which is beneficial to controlling the precipitation process and optimizing the morphology and specific surface area of the final precursor formed. The solid content of the first precursor slurry is preferably controlled to be 400 to 1000g/L and/or the solid content of the second precursor slurry is preferably controlled to be 200 to 800g/L. Water may be added during the second co-precipitation process as necessary to adjust the solids content of the final second precursor slurry.
In order to allow the components to react sufficiently, in some embodiments, the above-described preparation method further comprises: aging the second precursor slurry; preferably, the aging time is 0.5 to 5 hours. And (3) performing an aging reaction to form a precursor with relatively uniform morphology.
The magnetic impurities in the feedstock can cause shorting of the cell, so some embodiments provide for removal of the magnetic impurities in the precursor, the method further comprising: a demagnetizing step is added after the solution preparation step and after the aging reaction.
The solid-liquid separation in the preparation method can be implemented according to field equipment, such as sedimentation, filtration, suction filtration, filter pressing, centrifugation and the like. In order to reduce the cost and improve the efficiency, a suction filter is preferably adopted, and in order to further remove impurities, the second precursor slurry is washed by 1-5 times of pure water of the second precursor slurry in the solid-liquid separation process.
According to another aspect of the present invention, there is provided a positive electrode material, wherein the positive electrode material is prepared by calcining the precursor or the precursor prepared by the preparation method. As the spherical particles of the precursor have the flaky petal-shaped primary particles, the flaky petal-shaped primary particles have the width of 1-2 mu m, and the flaky petal-shaped morphology can increase the diffusion channel of lithium ions; the combination mode of the flaky petal-shaped primary particles in the precursor can influence the specific surface area and the strength of the material, but the specific surface area of the precursor is too large to easily cause the increase of side reaction, so the specific surface area of the precursor is controlled to be 4-10 m 2 And/g, the combination mode of flaky petal-shaped primary particles is controlled and regulated, so that the aim of reducing the generation of side reaction is fulfilled; the control of the specific surface area can also improve the strength of the material and inhibit the crushing and pulverization of particles; the assembled battery has good cycle performance.
In order to synthesize single crystals of a desired size and to avoid adverse effects of the calcination process on the cathode material, the calcination includes a first calcination and a second calcination, preferably the first calcination is at a temperature of 450 to 600 ℃, preferably the first calcination is for a time of 4 to 6 hours; the second calcination is preferably carried out at a temperature of 700 to 850 ℃, and the second calcination is preferably carried out for a time of 15 to 25 hours.
The first calcination is performed in an oxygen-enriched atmosphere, for example, in an oxygen-enriched atmosphere having an oxygen concentration of 90% or more, more preferably an oxygen-enriched atmosphere having an oxygen concentration of 99% or more, as is conventional in the art.
According to still another aspect of the present invention, there is provided a positive electrode of a lithium ion battery, including a positive electrode current collector and a positive electrode material layer including the positive electrode material. The positive electrode containing the positive electrode material of the lithium ion battery has higher cycle performance.
According to still another aspect of the present invention, there is provided a lithium ion battery comprising a positive electrode and a negative electrode, the positive electrode being the positive electrode described above. The lithium ion battery containing the lithium ion battery anode material has higher cycle performance.
The present application is described in further detail below in conjunction with specific embodiments, which should not be construed as limiting the scope of the claims.
Example 1
1) Dissolving nickel sulfate and manganese sulfate in pure water to prepare a salt solution with the molar ratio of nickel to manganese elements of 75:25, wherein the salt concentration of the salt solution is 1.8mol/L; preparing a precipitant solution from sodium hydroxide and ammonia water, wherein the concentration of the sodium hydroxide is 5mol/L and the concentration of the ammonia is 0.6mol/L, and demagnetizing the salt solution and the precipitant solution by a demagnetizer.
2) Adding the demagnetized salt solution and the precipitant solution into a reaction kettle at the same time to perform first coprecipitation treatment, controlling the rotation speed of the first stirring to 800rpm, controlling the temperature of the first coprecipitation treatment to 60 ℃, adjusting the flow of the precipitant solution, controlling the pH of the first coprecipitation treatment to 11.1, and controlling the reaction time of the first coprecipitation treatment to 36 hours to obtain first precursor slurry with the solid content of 400g/L;
3) The first precursor slurry is subjected to kettle separation, after the material of the first precursor slurry is discharged by one half, water is added into the rest part, the second coprecipitation treatment is carried out, the second stirring speed is 500rpm, the pH value of the second coprecipitation treatment is 11.5, the temperature of the second coprecipitation treatment is 65 ℃, the reaction time of the second coprecipitation treatment is 48 hours, and the second precursor slurry with the solid content of 200g/L is obtained;
4) Aging the second precursor slurry for 0.5h, discharging the aged second precursor slurry through a demagnetizer, performing solid-liquid separation, and washing with 1 time of pure water at 80 ℃;
5) And drying the washed solid material at 120 ℃ for 24 hours to obtain the cobalt-free binary precursor.
The precursor prepared in this example has the chemical formula [ Ni ] 0.75 Mn 0.25 ](OH) 2 The particle diameter D is detected by a laser particle sizer 50 The precursor primary particles are petal-shaped with the width of 1-2 μm, and the SEM is shown in fig. 1, so that the petal-shaped flaky lamellar planes are exposed more, the specific surface area of the spherical particles is controlled, and the overlarge specific surface area caused by too many petal-shaped flaky thickness directions is avoided. BET measurement shows that the specific surface area is 5.4m 2 And/g. Then fully mixing lithium hydroxide with precursor, over 0.06wt% of lithium hydroxide, calcining for 6 hr at 500 deg.C in air atmosphere, then pulverizing and secondary sintering treatment at 740 deg.C for 18 hr to obtain cobalt-free positive electrode material Li [ Ni ] 0.75 Mn 0.25 ]O 2 。
Example 2
1) Dissolving nickel sulfate, cobalt sulfate and manganese sulfate in pure water to prepare a nickel-cobalt-manganese element with the molar ratio of 80:8:12, wherein the salt concentration of the salt solution is 1.5mol/L, sodium hydroxide and ammonia water are prepared into a precipitator solution, and the concentration of the sodium hydroxide is 5mol/L and the concentration of the ammonia is 0.6mol/L;
2) Simultaneously adding the salt solution and the precipitant solution into a reaction kettle to perform first coprecipitation treatment, controlling the rotation speed of the first stirring to 700rpm, controlling the temperature of the first coprecipitation treatment to 55 ℃, adjusting the flow of the precipitant solution, controlling the pH of the first coprecipitation treatment to be 11, and reacting for 30 hours to obtain first precursor slurry;
3) The first precursor slurry is subjected to kettle separation, one half of the materials of the first precursor slurry are discharged, water is added, the first precursor slurry is subjected to second coprecipitation treatment, the second stirring speed is 400rpm, the pH value of the second coprecipitation treatment is 11.3, the temperature of the second coprecipitation treatment is 60 ℃, and the reaction time of the second coprecipitation treatment is 40 hours;
4) Aging the second precursor slurry for 0.5h, demagnetizing the aged second precursor slurry, performing solid-liquid separation, and washing with 1 time of pure water at 80 ℃;
5) And drying the washed solid material at 120 ℃ for 24 hours to obtain the ternary precursor.
The ternary precursor prepared in this example has the chemical formula [ Ni ] 0.8 Co 0.08 Mn 0.12 ](OH) 2 . Then fully mixing lithium hydroxide with precursor, over 0.05wt% of lithium hydroxide, calcining at 500 deg.C for 5 hr, then pulverizing and secondary sintering treatment at 720 deg.C for 20 hr to obtain ternary positive electrode material Li [ Ni ] 0.8 Co 0.08 Mn 0.12 ]O 2 。
Example 3
Unlike example 1, in step 2), the ratio of sodium hydroxide to ammonia water was controlled to be constant, the amount of the precipitant was adjusted, and in step 3), the pH was controlled to be 12 and 13.
Example 4
Unlike example 1, in step 2), the ratio of sodium hydroxide to ammonia water was controlled to be constant, the amount of the precipitant was adjusted, and in step 3), the pH was controlled to be 11.5, and the pH was controlled to be 12.4.
Example 5
Unlike example 1, in step 2), the temperature of the first coprecipitation was 40 ℃.
Example 6
Unlike example 1, in step 2), the temperature of the first coprecipitation was 80 ℃.
Example 7
Unlike example 1, in step 2), the temperature of the first coprecipitation was 30 ℃.
Example 8
Unlike example 1, in step 2), the temperature of the first coprecipitation was 85 ℃.
Example 9
Unlike example 1, in step 3), the temperature of the second coprecipitation was 50 ℃.
Example 10
Unlike example 1, in step 3), the temperature of the second coprecipitation was 80 ℃.
Example 11
Unlike example 1, in step 3), the temperature of the second coprecipitation was 90 ℃.
Example 12
Unlike example 1, in step 3), the temperature of the second coprecipitation was 40 ℃.
Example 13
Unlike example 1, the rotation speed was 1000rpm in step 2), and 500rpm in step 3).
Example 14
Unlike example 1, the rotation speed was 800rpm in step 2), and 100rpm in step 3).
Example 15
Unlike example 1, the salt concentration of the salt solution was 0.5mol/L.
Example 16
Unlike example 1, the salt concentration of the salt solution was 0.8mol/L.
Example 17
Unlike example 1, the salt concentration of the salt solution was 0.4mol/L.
Example 18
Unlike example 1, the salt concentration of the salt solution was 2mol/L.
Example 19
Unlike example 1, the salt concentration of the salt solution was 2.5mol/L.
Example 20
Unlike example 1, in the precipitant solution, the sodium hydroxide concentration was 2.5mol/L, and the ammonia concentration was unchanged, and the pH values of the first and second coprecipitates were maintained as in example 1 by changing the amount of the precipitant solution.
Example 21
Unlike example 1, the pH of the first and second coprecipitates was maintained at the same value as in example 1 by changing the amount of the precipitant solution in which the concentration of sodium hydroxide was 3.5mol/L and the concentration of ammonia was unchanged
Example 22
Unlike example 1, in the precipitant solution, the sodium hydroxide concentration was 1mol/L, and the ammonia concentration was unchanged, and the pH values of the first and second coprecipitates were maintained the same as in example 1 by changing the amount of the precipitant solution.
Example 23
Unlike example 1, in the precipitant solution, the ammonia concentration was 1.5mol/L, and the sodium hydroxide concentration was unchanged, and the pH values of the first and second coprecipitates were maintained as in example 1 by changing the amount of the precipitant solution.
Example 24
Unlike example 1, in the precipitant solution, the ammonia concentration was 0.02mol/L, and the sodium hydroxide concentration was unchanged, and the pH values of the first and second coprecipitates were maintained as in example 1 by changing the amount of the precipitant solution.
Example 25
Unlike example 1, in the precipitant solution, the ammonia concentration was 2.5mol/L, and the sodium hydroxide concentration was unchanged, and the pH values of the first and second coprecipitates were maintained as in example 1 by changing the amount of the precipitant solution.
Comparative example 1
1) Dissolving nickel sulfate and manganese sulfate in pure water to prepare a salt solution with the molar ratio of nickel to manganese elements of 75:25, wherein the salt concentration of the salt solution is 1.8mol/L; sodium hydroxide and ammonia water are prepared into a precipitant solution, wherein the concentration of sodium hydroxide is 5mol/L and the concentration of ammonia is 0.6mol/L.
2) Adding the salt solution and the precipitant solution into a reaction kettle at the same time for first coprecipitation treatment, controlling the stirring rotation speed to 700rpm, controlling the coprecipitation temperature to 60 ℃, adjusting the flow of the precipitant solution, controlling the pH value to 11.1, and controlling the reaction time of the first coprecipitation treatment to 50 hours to obtain precursor slurry;
3) Aging the precursor slurry for 0.5h, discharging the aged precursor slurry through a demagnetizer, performing solid-liquid separation, and washing with 1 time of pure water at 80 ℃;
4) And drying the washed solid material at 120 ℃ for 24 hours to obtain the cobalt-free binary precursor.
The chemical formula of the precursor prepared in this comparative example is [ Ni ] 0.75 Mn 0.25 ](OH) 2 The particle diameter D is detected by a laser particle sizer 50 The precursor is spherical. Then fully mixing lithium hydroxide with precursor, over 0.06wt% of lithium hydroxide, calcining for 6 hr at 500 deg.C in air atmosphere, then pulverizing and secondary sintering treatment at 740 deg.C for 18 hr to obtain cobalt-free positive electrode material Li [ Ni ] 0.75 Mn 0.25 ]O 2 。
Comparative example 2
1) Dissolving nickel sulfate and manganese sulfate in pure water to prepare a salt solution with the molar ratio of nickel to manganese elements of 75:25, wherein the salt concentration of the salt solution is 1.8mol/L; sodium hydroxide and ammonia water are prepared into a precipitant solution, wherein the concentration of sodium hydroxide is 5mol/L and the concentration of ammonia is 0.6mol/L.
2) Adding the salt solution and the precipitant solution into a reaction kettle at the same time to perform first coprecipitation treatment, controlling the rotation speed of the first stirring to be 500rpm, controlling the temperature of the first coprecipitation treatment to be 60 ℃, adjusting the flow of the precipitant solution, controlling the pH of the first coprecipitation treatment to be 11.1, and controlling the reaction time of the first coprecipitation treatment to be 36 hours to obtain first precursor slurry;
3) Performing second coprecipitation treatment on the first precursor slurry, wherein the second stirring speed is 800rpm, the pH value of the second coprecipitation treatment is 11.5, the temperature of the second coprecipitation treatment is 65 ℃, and the reaction time of the second coprecipitation treatment is 48 hours, so as to obtain second precursor slurry;
4) Aging the second precursor slurry for 0.5h, demagnetizing the aged second precursor slurry, performing solid-liquid separation, and washing with 1 time of pure water at 80 ℃;
5) And drying the washed solid material at 120 ℃ for 24 hours to obtain the cobalt-free binary precursor.
The chemical formula of the precursor prepared in this comparative example is [ Ni ] 0.75 Mn 0.25 ](OH) 2 Particle diameter D 50 =2.1 μm, specific surface area 15m 2 And/g. Then fully mixing lithium hydroxide with precursor, over 0.06wt% of lithium hydroxide, calcining for 6 hr at 500 deg.C in air atmosphere, then pulverizing and secondary sintering treatment at 740 deg.C for 18 hr to obtain cobalt-free positive electrode material Li [ Ni ] 0.75 Mn 0.25 ]O 2 。
Comparative example 3
1) Dissolving nickel sulfate and manganese sulfate in pure water to prepare a salt solution with the molar ratio of nickel to manganese elements of 75:25, wherein the salt concentration of the salt solution is 1.8mol/L; sodium hydroxide and ammonia water are prepared into a precipitant solution, wherein the concentration of sodium hydroxide is 5mol/L and the concentration of ammonia is 0.6mol/L.
2) Adding the salt solution and the precipitant solution into a reaction kettle at the same time to perform first coprecipitation treatment, controlling the rotation speed of the first stirring to 800rpm, controlling the temperature of the first coprecipitation treatment to 60 ℃, adjusting the flow of the precipitant solution, controlling the pH of the first coprecipitation treatment to 11.1, and controlling the reaction time of the first coprecipitation treatment to 36 hours to obtain first precursor slurry;
3) Performing second coprecipitation treatment on the first precursor slurry, wherein the second stirring speed is 600rpm, the pH value of the second coprecipitation treatment is 10.1, the temperature of the second coprecipitation treatment is 65 ℃, and the reaction time of the second coprecipitation treatment is 48 hours, so as to obtain second precursor slurry;
4) Aging the second precursor slurry for 0.5h, demagnetizing the aged second precursor slurry, performing solid-liquid separation, and washing with 1 time of pure water at 80 ℃;
5) And drying the washed solid material at 120 ℃ for 24 hours to obtain the cobalt-free binary precursor.
The chemical formula of the precursor prepared in this comparative example is [ Ni ] 0.75 Mn 0.25 ](OH) 2 Particle diameter D 50 =8μm, specific surface area 3.5m 2 And/g. Then fully mixing lithium hydroxide with precursor, over 0.06wt% of lithium hydroxide, calcining for 6 hr at 500 deg.C in air atmosphere, then pulverizing and secondary sintering treatment at 740 deg.C for 18 hr to obtain cobalt-free positive electrode material Li [ Ni ] 0.75 Mn 0.25 ]O 2 。
The positive electrode materials prepared in each example and comparative example were mixed with SP (carbon black conductive agent), PVDF (polyvinylidene fluoride) in the following proportions: 92:4:4. And (3) pulping and stirring for several hours by using NMP (N-methyl pyrrolidone) as a solvent to prepare the lithium ion half cell, and carrying out charge and discharge test at 3.0-4.3V by using a blue electric tester.
The 0.1C discharge gram capacity of the battery prepared in example 1 was 197.7mAh, the 1.0C discharge capacity was 176.4mAh, and the capacity retention rate at 50 cycles was 96.7%. The cycle performance curves of example 1 and comparative example 1 are shown in fig. 2.
TABLE 1
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Precursor D obtained in example 9 above 50 Smaller, and smaller specific surface area, and the SEM observation shows that the spherical particles with petals are smaller, and the rod-shaped particles are larger, probably because the first precipitation temperature is high, the formed primary particles are more and more mature, and the second precipitation is difficult to grow into the spherical particles with petals.
Precursor D obtained in example 12 above 50 Smaller, and smaller specific surface area, and the SEM observation also shows that the spherical particles with petals have smaller occupation and larger flaky occupation, probably due to the high temperature of the secondary precipitation, the secondary precipitation particles grow too fast and are difficult to growSpherical particles with petals are grown.
In example 25, the complexing agent was used in a large amount, which resulted in a large precursor particle size and a small specific surface area.
TABLE 2
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From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:
the precursor comprises flaky particles and petal-shaped particles, wherein the flaky petal-shaped particles can increase a diffusion channel of lithium ions, and the flaky particles have higher strength relative to the petal-shaped particles; the ratio of the particles with two morphologies can influence the specific surface area and the strength of the material, but the specific surface area of the precursor is too large to easily cause the increase of side reaction, so the specific surface area of the precursor is controlled to be 4-10 m 2 And/g to control the duty ratio of the flaky petal-shaped particles, thereby achieving the purpose of reducing the generation of side reactions; the control of the specific surface area is also beneficial to increasing the duty ratio of the flaky particles, so that the strength of the material is improved, and the crushing and pulverization of the particles are inhibited; the assembled battery has good cycle performance.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (30)
1. A preparation method of a positive electrode material precursor is characterized in that the positive electrode material precursor is a binary precursor or a ternary precursor, the precursor comprises spherical particles,the spherical particles are sheet petal-shaped primary particles, the width of each sheet petal is 1-2 mu m, and the specific surface area of the precursor is 4-10 m 2 /g；
The preparation method comprises the following steps:
step S1, under a first stirring condition, carrying out first coprecipitation treatment on a salt solution by adopting a precipitant, wherein the salt solution is a salt solution containing nickel and manganese or a salt solution containing nickel, cobalt and manganese, the pH value of the first coprecipitation treatment is 11-12, and the speed of the first stirring is 500-1000 rpm, so as to obtain first precursor slurry;
s2, under a second stirring condition, carrying out second coprecipitation treatment on the first precursor slurry by adopting the precipitant, wherein the pH value of the second coprecipitation treatment is 11.3-13, the pH value of the second coprecipitation treatment is larger than that of the first coprecipitation treatment, the difference value between the pH value of the second coprecipitation treatment and the pH value of the first coprecipitation treatment is 0.3-1, the speed of the second stirring is 100-500 rpm, the speed of the second stirring is smaller than that of the first stirring, and the speed of the second stirring is 50% -80% of that of the first stirring, so that the second precursor slurry is obtained;
step S3, carrying out solid-liquid separation and drying on the second precursor slurry to obtain the positive electrode material precursor;
the precipitant comprises sodium hydroxide and a complexing agent; the complexing agent is selected from one or more of ammonia water, amino acid, polypeptide and sulfamic acid.
2. The method of claim 1, wherein the binary precursor has the general formula Ni x Mn y (OH) 2 Wherein x is more than or equal to 0.5 and less than or equal to 0.8, y is more than or equal to 0.2 and less than or equal to 0.5, and x+y=1.
3. The method of claim 1, wherein the ternary precursor has the general formula Ni a Co b Mn c (OH) 2 Wherein a is more than or equal to 0.5 and less than or equal to 0.8,0<b≤0.2，0.1≤c≤0.5，a+b+c=1。
4. The method according to any one of claims 1 to 3, wherein the precursor has a specific surface area of 4.4 to 6.8m 2 /g; and/or D of the precursor 50 3 to 10 μm.
5. The method of claim 4, wherein D is the precursor 50 3.4 to 5.6 μm.
6. The method according to claim 1, wherein in the step S1, the temperature of the first coprecipitation treatment is 40 to 80 ℃.
7. The method according to claim 6, wherein the temperature of the first coprecipitation treatment is 45 to 60 ℃.
8. The method according to claim 1, wherein the first coprecipitation treatment time is 30 to 50 hours.
9. The method according to claim 1, wherein in the step S2, the temperature of the second coprecipitation treatment is 50-80 ℃.
10. The method according to claim 1, wherein the second coprecipitation treatment time is 40 to 60 hours.
11. The method according to claim 1, wherein the temperature of the second coprecipitation treatment is not less than the temperature of the first coprecipitation treatment.
12. The method according to claim 1, wherein the salt in the salt solution comprises two or three of nickel sulfate, cobalt sulfate, and manganese sulfate; the total molar concentration of nickel and manganese elements in the nickel-manganese-containing salt solution is 0.5-2 mol/L, and the molar ratio of nickel to manganese is 0.5-0.8: 0.2-0.5; the total molar concentration of nickel, cobalt and manganese elements in the salt solution containing nickel, cobalt and manganese is 0.5-2 mol/L, and the molar ratio of nickel to cobalt to manganese is 0.5-0.8: 0-0.2: 0.1 to 0.5, and the cobalt content is not zero.
13. The method for preparing the aqueous solution according to claim 12, wherein the salt concentration of the salt solution is 1-2 mol/L.
14. The method according to claim 1, wherein the amino acid comprises an amino acid having a basic isoelectric point.
15. The method of claim 14, wherein the amino acid is lysine and/or arginine.
16. The preparation method of claim 1, wherein the concentration of sodium hydroxide in the precipitant solution is 2-10 mol/L.
17. The method according to claim 16, wherein the concentration of sodium hydroxide is 2.5 to 5mol/L.
18. The method of claim 1, wherein the complexing agent is present at a concentration of 0.02 to 2.0mol/L.
19. The method of claim 18, wherein the complexing agent is present at a concentration of 0.05 to 1.5mol/L.
20. The method of claim 19, wherein the complexing agent is present at a concentration of 0.3 to 1.2mol/L.
21. The method of manufacturing according to claim 1, characterized in that the method of manufacturing further comprises: the second precursor slurry is aged.
22. The method of claim 21, wherein the aging time is 0.5 to 5 hours.
23. A positive electrode material, wherein the positive electrode material is prepared by calcining a precursor prepared by the preparation method of any one of claims 1 to 22.
24. The positive electrode material of claim 23, wherein the calcining comprises a first calcining and a second calcining.
25. The positive electrode material according to claim 24, wherein the first calcination temperature is 450 to 600 ℃.
26. The positive electrode material of claim 24, wherein the first calcination time is 4 to 6 hours.
27. The positive electrode material according to claim 24, wherein the second calcination temperature is 700 to 850 ℃.
28. The positive electrode material according to any one of claims 24 to 27, wherein the second calcination time is 15 to 25 hours.
29. A positive electrode of a lithium ion battery comprising a positive electrode current collector and a positive electrode material layer, characterized in that the positive electrode material layer comprises the positive electrode material of any one of claims 24 to 28.
30. A lithium ion battery comprising a positive electrode and a negative electrode, wherein the positive electrode is the positive electrode of claim 29.
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| CN104347867A (en) * | 2013-07-26 | 2015-02-11 | 比亚迪股份有限公司 | Lithium battery cathode material and preparation method thereof |
| CN107394191A (en) * | 2017-06-22 | 2017-11-24 | 芜湖浙鑫新能源有限公司 | Flower-shaped ternary anode material for lithium-ion batteries and preparation method thereof |
| CN107565125A (en) * | 2017-08-25 | 2018-01-09 | 湖南杉杉能源科技股份有限公司 | A kind of high voltage precursor of nickel-cobalt-lithium-manganese-oxide and preparation method thereof and high voltage nickel-cobalt lithium manganate cathode material |
| CN107895792A (en) * | 2017-10-26 | 2018-04-10 | 深圳市沃特玛电池有限公司 | A kind of preparation method of nickel cobalt aluminium ternary precursor and positive electrode |
| CN111384389A (en) * | 2018-12-27 | 2020-07-07 | 中信国安盟固利动力科技有限公司 | Precursor of ternary material |
| CN112234169A (en) * | 2019-07-15 | 2021-01-15 | 比亚迪股份有限公司 | Lithium ion battery positive electrode material, preparation method thereof and lithium ion battery |
| CN112624213A (en) * | 2020-12-18 | 2021-04-09 | 广东佳纳能源科技有限公司 | Preparation method of ternary precursor, positive electrode material and lithium ion battery |
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