Cobalt-free cathode material precursor, its preparation method, cathode material and application

Abstract

The present invention relates to the technical field of lithium battery (IPC classification number: H01M4 / 58), and particularly relates to a cobalt-free cathode material precursor, a preparation method thereof, a cathode material and an application. The preparation method of the cobalt-free cathode material precursor includes adding a bottom liquid into a reaction kettle under an inert gas, oxygen or air atmosphere, and then continuously adding an aqueous solution of nickel salt and manganese salt, a precipitant, an oxidant or an oxygen-containing gas, adjusting the pH value and ammonia concentration of the system, and reacting to obtain the precursor. The precursor of the cobalt-free battery prepared by the oxidation system in the present invention is confirmed by an electron microscope photograph to be internally loose and porous, and the primary particles are small. The further prepared cathode material has fine micropores inside, which is beneficial to the rapid diffusion of lithium ions in the lithium battery, and a cobalt-free cathode material with excellent electrochemical performance is obtained, and both the capacity and rate performance are higher than the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries (IPC classification number H01M4 / 58), and particularly relates to a cobalt-free cathode material precursor, a preparation method thereof, a cathode material, and an application. Background Art

[0002] With the rapid development of new energy vehicles and energy storage and the strong support of the country, the demand for lithium batteries has increased sharply. As is well known, cobalt ore in China is widely distributed with a high concentration, but cobalt resources are still relatively scarce, specifically manifested as small reserves, low ore grades, many lean ores, and many associated ores. China has a high dependence on imported cobalt resources. The cobalt price is high and volatile, and reducing the cobalt content in ternary materials is crucial for the overall cost control of cathode manufacturers.

[0003] There is a preparation technology for cobalt-free precursors in the prior art. Chinese Patent CN111807425A discloses a method for preparing a high-performance ternary cathode material for lithium-ion batteries at a low ammonia concentration. The ammonia concentration is controlled as low as 0.05 mol / L in the specification. -1 Chinese Patent CN112086616B discloses a preparation method of a large (010) crystal plane nickel cobalt manganese / aluminum layered cathode material, and the preferred ammonia concentration is 0.3 - 0.4 mol / L, but a scheme with an ammonia concentration of 0 cannot be achieved.

[0004] According to the current situation, the present invention uses a preparation technology for a precursor with a special morphology to improve the capacity and rate performance of the cobalt-free cathode material without affecting the performance of the cathode material, so as to achieve the purpose of reducing costs. Summary of the Invention

[0005] The first aspect of the present invention provides a cobalt-free cathode material precursor, and the chemical formula of the precursor includes at least one of Ni a Mn b (OH)2, Ni c Mn d CO3, where a is 0.5 - 1.0, b is 0 - 0.5, c is 0.5 - 1.0, and d is 0 - 0.5.

[0006] Cobalt-free batteries are widely welcomed due to their advantages such as low cost. However, the biggest disadvantages are low rate performance and low capacity. Using the current existing precursor and cathode roasting processes, the effects of improving capacity and rate performance cannot be achieved. In addition, after high-temperature roasting, lithium-nickel mixing is serious and the battery stability is poor, which requires a higher thermal management system for the battery pack. In mass production, the yield and consistency of the batteries still need to be tested.

[0007] The second aspect of the present invention provides a method for preparing a cobalt-free cathode material precursor, specifically including: in an inert gas, oxygen or air atmosphere, after adding a bottom liquid into a reaction kettle, successively adding an aqueous solution of nickel salt and manganese salt, a precipitant, an oxidant or an oxygen-containing gas, regulating the pH value and ammonia concentration of the system, and reacting to obtain the precursor.

[0008] In some embodiments, the bottom liquid is an aqueous solution of an inorganic base or an organic base, including but not limited to aqueous solutions of inorganic bases such as ammonia water, sodium hydroxide, potassium hydroxide, etc., or organic bases such as sodium methoxide, potassium ethoxide, potassium tert-butoxide, etc., and the specific concentration is 0 - 5 mol / L but not 0.

[0009] In order to reduce the ammonia concentration and maintain the precursor performance, in some embodiments, the pH value is 9.0 - 14.0, and the specific pH values include natural numbers between 9.0 and 14.0, which can be enumerated as 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10, 11, 12, 13, 14.

[0010] During the synthesis process of the precursor, ammonia water acts as a complexing agent and plays a very important role. When there is no complexing agent, the precursor morphology is loose and the tap density is relatively low. When there is a complexing agent, the precursor is dense and the tap density increases. However, when the ammonia water concentration is too high, too many nickel and cobalt ions are complexed in the solution, which will cause incomplete reaction. In addition, it will also cause too high ammonia concentration in the wastewater, which is not conducive to environmental protection treatment. In some embodiments, the ammonia concentration is 0 - 6 g / L, and the specific ammonia concentration values include natural numbers between 0 and 6, which can be enumerated as 0 g / L, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 1.0 g / L, 2.0 g / L, 3.0 g / L, 4.0 g / L, 5.0 g / L, 6.0 g / L. Through the establishment of a specific oxidation system and pH system, the present invention can achieve a reaction with an ammonia concentration of 0, and the prepared precursor and cathode material have a low true density and good wettability.

[0011] Theoretically, the longer the reaction time, the more complete the reaction. In some embodiments, the reaction time is 20 - 200 h, but after reaching a certain time, further reaction does not significantly optimize the primary particle characterization. From an economic perspective, the preferred reaction time is 20 - 100 h. The reaction temperature is 35 - 65 °C.

[0012] In some embodiments, the molar ratio of the nickel salt to the manganese salt is (5 - 10):(0 - 5) but not 0.

[0013] The nickel salt and manganese salt described in the present invention include but are not limited to at least one of sulfates, nitrates, and acetates of nickel and manganese.

[0014] The precipitants described in the present invention include, but are not limited to, inorganic bases such as ammonia water, sodium hydroxide, potassium hydroxide, etc. or aqueous solutions of organic bases such as sodium methoxide, potassium ethoxide, potassium tert-butoxide, etc.

[0015] In some embodiments, the oxidant includes at least one of hydrogen peroxide, sodium peroxide, potassium peroxide, magnesium peroxide, calcium peroxide, barium peroxide, peracetic acid, sodium dichromate, potassium dichromate, chromic acid, nitric acid, sulfuric acid, potassium permanganate, ammonium persulfate, sodium hypochlorite, potassium hypochlorite, sodium percarbonate, potassium percarbonate, sodium perborate, potassium perborate, fluorine, chlorine, bromine, iodine.

[0016] The applicant has found that by establishing an oxidation system under specific pH conditions of the present invention and regulating the ammonia concentration and reaction time, the growth process of primary particles can be controlled to grow into nano-particles with thin and delicate lamellae, large specific surface area, and loose and porous surfaces, which is further conducive to diffusion in lithium batteries and can improve the performance, especially the stability, of cobalt-free batteries.

[0017] The third aspect of the present invention provides a cathode material, and the raw materials for preparing the cathode material include: lithium salt, additive, and precursor.

[0018] In some embodiments, the method for preparing the cathode material includes: sampling and mixing lithium salt and precursor evenly according to a molar ratio of 1:(1 - 1.2), adding an additive, heating to 600 - 1000 °C and holding for 6 - 30 h, cooling, roller compressing and crushing, and sieving to remove magnetism to obtain a cobalt-free cathode material.

[0019] The lithium salt includes, but is not limited to, Li2CO3.

[0020] The elements in the additive include at least one of oxides, carbonates, nitrates, and acetates of Mg, Sr, B, F, P, Ti, Zr, Mo, W, Y, La, Ce.

[0021] The fourth aspect of the present invention provides the application of the precursor and / or the preparation method of the precursor and / or the cathode material in the preparation of lithium batteries.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. As Figures 1-3 shown, the precursor of the cobalt-free battery prepared by the oxidation system of the present invention is confirmed by electron microscope photos to be internally loose and porous, and the primary particles are fine. The further prepared cathode material has fine micropores inside, which is beneficial to the rapid diffusion of lithium ions in lithium batteries, and a cobalt-free cathode material with excellent electrochemical performance is obtained, and both the capacity and rate performance are higher than the prior art.

[0024] 2. The ammonia concentration within the system of the present invention can be as low as 0 g / L. The prepared precursor and cathode material have the same effect as the cathode materials with high-concentration ammonia addition in the prior art. In contrast, it reduces the production cost and environmental protection pressure of enterprises.

[0025] 3. As Figure 5 shown, within the specific pH and oxidation system of the present invention, in an atmosphere of low ammonia, good complexation of the precursor can still be achieved, and the crystal nucleation rate is relatively low, which is conducive to the agglomeration and growth of the precursor, and further conducive to diffusion in lithium batteries, and can improve the performance, especially the stability, of cobalt-free batteries.

[0026] 4. As Figure 4 shown, it has been experimentally confirmed that the initial specific capacity of the cathode material prepared by the present invention is as high as 182.6 mAh / g, and the true density is 4.5534 g / cm 3 , both of which are superior to the prior art, which is an effective breakthrough in the technology of the cobalt-free lithium battery industry and has extremely high market value and application prospects.

[0027] 5. The preparation process of the present invention is easy to operate, the raw materials are simple and easy to obtain, the parameters of each process section are accurately controllable, the operation is simple, the degree of automation is high, and it is easy to scale up, being suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the electron microscope photograph of the precursor prepared in Example 1 and Comparative Example 1 (expressed as Comparative Example 1 in the picture), where the upper left and lower left are the high-magnification and low-magnification electron microscopes (overflow material) of the growth process in Comparative Example 1, and the upper right and lower right are the high-magnification and low-magnification electron microscopes (overflow material) of the growth process in Example 1.

[0029] Figure 2 is the electron microscope photograph of the precursors in Example 1 and Comparative Example 1 (expressed as Comparative Example 1 in the picture), where the upper left and lower left are the electron microscopes of the precursor finished products in Comparative Example 1, and the upper right and lower right are the electron microscopes of the precursor finished products in Example 1.

[0030] Figure 3 is the electron microscope photograph of the cathode material prepared in Example 1 and Comparative Example 1 (expressed as Comparative Example 1 in the picture), where the upper left and lower left are the electron microscopes of the cathode material in Comparative Example 1, and the upper right and lower right are the electron microscopes of the cathode material in Example 1.

[0031] Figure 4 is the comparison chart of the charge-discharge curves of the cathode materials prepared in Example 1 and Comparative Example 1.

[0032] Figure 5 is the normal-temperature and high-temperature cycling performance of the cathode materials prepared in Example 1 and Comparative Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Example 1

[0034] The first aspect of this embodiment provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0035] The second aspect of this embodiment provides a method for preparing a cobalt-free cathode material precursor, which specifically includes: while introducing oxygen as an oxidant (flow rate: 0.2 mL / min) under a nitrogen atmosphere, after adding 5 L of bottom liquid into the reaction kettle, continue to introduce an aqueous solution of 2 mol / L nickel salt and 2 mol / L manganese salt (molar ratio 2.2:1.8) (flow rate: 0.3 L / h) and a precipitant (flow rate: 0.1 L / h). The online pH meter monitors at 11.0, the ammonia concentration is 0 g / L, continuously stir and react at 45 °C for 100 h to obtain the precursor.

[0036] The bottom liquid is 2 mol / L ammonia water, the precipitant is 1 mol / L sodium hydroxide, the nickel salt is nickel sulfate, and the manganese salt is manganese sulfate.

[0037] The third aspect of this embodiment provides a cathode material. The preparation raw materials of the cathode material include: lithium salt, additive, and precursor. The preparation method includes: sampling and mixing the lithium salt and the precursor evenly according to a molar ratio of 1:1.05, adding the additive, heating to 850 °C, holding for 10 h, cooling, roller compressing and crushing, and sieving to remove magnetism to obtain the cobalt-free cathode material.

[0038] The lithium salt is Li2CO3. The additive is Al2O3, and the addition amount is 2000 ppm of the total weight of the lithium salt and the precursor.

[0039] The fourth aspect of this embodiment provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0040] Example 2

[0041] The first aspect of this embodiment provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.65 Mn 0.35 (OH)2.

[0042] The second aspect of this embodiment provides a method for preparing a cobalt-free cathode material precursor. The specific implementation method is the same as that of Example 1, except that the molar ratio of the nickel salt to the manganese salt is 1.3:0.7.

[0043] The third aspect of this embodiment provides a cathode material. The specific implementation method is the same as that of Example 1.

[0044] The fourth aspect of this embodiment provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0045] Example 3

[0046] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0047] The second aspect of this example provides a method for preparing a cobalt-free cathode material precursor. The specific implementation is the same as that of Example 1, except that the ammonia concentration is 2 g / L.

[0048] The third aspect of this example provides a cathode material. The specific implementation is the same as that of Example 1.

[0049] The fourth aspect of this example provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0050] Example 4

[0051] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0052] The second aspect of this example provides a method for preparing a cobalt-free cathode material precursor. The specific implementation is the same as that of Example 1, except that the ammonia concentration is 4 g / L.

[0053] The third aspect of this example provides a cathode material. The specific implementation is the same as that of Example 1.

[0054] The fourth aspect of this example provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0055] Example 5

[0056] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0057] The second aspect of this example provides a method for preparing a cobalt-free cathode material precursor. The specific implementation is the same as that of Example 1, except that the ammonia concentration is 6 g / L.

[0058] The third aspect of this example provides a cathode material. The specific implementation is the same as that of Example 1.

[0059] The fourth aspect of this example provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0060] Example 6

[0061] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0062] The second aspect of this example provides a preparation method of the cobalt-free cathode material precursor. The specific implementation method is the same as that of Example 1, except that the on-line pH meter monitoring is 10.0.

[0063] The third aspect of this example provides a cathode material. The specific implementation method is the same as that of Example 1.

[0064] The fourth aspect of this example provides the application of the precursor, its preparation method and the cathode material in the preparation of lithium batteries.

[0065] Example 7

[0066] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0067] The second aspect of this example provides a preparation method of the cobalt-free cathode material precursor. The specific implementation method is the same as that of Example 1, except that the on-line pH meter monitoring is 14.0.

[0068] The third aspect of this example provides a cathode material. The specific implementation method is the same as that of Example 1.

[0069] The fourth aspect of this example provides the application of the precursor, its preparation method and the cathode material in the preparation of lithium batteries.

[0070] Example 8

[0071] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0072] The second aspect of this example provides a preparation method of the cobalt-free cathode material precursor. The specific implementation method is the same as that of Example 1, except that the on-line pH meter monitoring is 12.0 and the ammonia concentration is 5 g / L.

[0073] The third aspect of this example provides a cathode material. The specific implementation method is the same as that of Example 1.

[0074] The fourth aspect of this example provides the application of the precursor, its preparation method and the cathode material in the preparation of lithium batteries.

[0075] Example 9

[0076] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0077] The second aspect of this example provides a method for preparing a cobalt-free cathode material precursor, and the specific implementation is the same as that of Example 1.

[0078] The third aspect of this example provides a cathode material, and the specific implementation is the same as that of Example 1, except that the lithium salt and the precursor are sampled and mixed evenly according to a molar ratio of 1:1.02.

[0079] The fourth aspect of this example provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0080] Example 10

[0081] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0082] The second aspect of this example provides a method for preparing a cobalt-free cathode material precursor, and the specific implementation is the same as that of Example 1.

[0083] The third aspect of this example provides a cathode material, and the specific implementation is the same as that of Example 1, except that it is heated to 900 °C and held for 10 h.

[0084] The fourth aspect of this example provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0085] Example 11

[0086] The first aspect of this example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0087] The second aspect of this embodiment provides a method for preparing a cobalt-free cathode material precursor. The specific implementation is the same as that of Embodiment 1, except that after adding 5 L of the bottom liquid into the reaction kettle under a nitrogen atmosphere, an aqueous solution of 2 mol / L nickel salt and 2 mol / L manganese salt (molar ratio of 2.2:1.8) (flow rate of 1 L / h), a precipitant (flow rate of 2 L / h), and an oxidant (flow rate of 1 mL / min) are continuously added. The online pH meter monitors at 11.0, the ammonia concentration is 0 g / L, and continuous stirring reaction is carried out at 45 °C for 100 h to obtain the precursor. The oxidant is hydrogen peroxide.

[0088] The third aspect of this embodiment provides a cathode material. The specific implementation is the same as that of Embodiment 1.

[0089] The fourth aspect of this embodiment provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0090] Embodiment 12

[0091] The first aspect of this embodiment provides a cobalt-free cathode material precursor. The chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0092] The second aspect of this embodiment provides a method for preparing a cobalt-free cathode material precursor. The specific implementation is the same as that of Embodiment 11, except that the oxidant is oxygen simultaneously introduced under a N2 protective atmosphere.

[0093] The third aspect of this embodiment provides a cathode material. The specific implementation is the same as that of Embodiment 1.

[0094] The fourth aspect of this embodiment provides the application of the precursor, its preparation method, and the cathode material in the preparation of lithium batteries.

[0095] Embodiment 13

[0096] The first aspect of this embodiment provides a cobalt-free cathode material precursor. The chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0097] The second aspect of this embodiment provides a method for preparing a cobalt-free cathode material precursor. The specific implementation is the same as that of Embodiment 11, except that the oxidant is air simultaneously introduced under a N2 protective atmosphere.

[0098] The third aspect of this embodiment provides a cathode material. The specific implementation is the same as that of Embodiment 1.

[0099] The fourth aspect of this embodiment provides a precursor, its preparation method, and the application of a cathode material in the preparation of a lithium battery.

[0100] Comparative Example 1

[0101] The first aspect of this comparative example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0102] The second aspect of this comparative example provides a preparation method of a cobalt-free cathode material precursor. The specific implementation manner is the same as that of Example 1, except that the on-line pH meter monitors at 12.0 and the ammonia concentration is 7 g / L.

[0103] The third aspect of this comparative example provides a cathode material. The specific implementation manner is the same as that of Example 1.

[0104] The fourth aspect of this comparative example provides the application of the precursor, its preparation method, and the cathode material in the preparation of a lithium battery.

[0105] Comparative Example 2

[0106] The first aspect of this comparative example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0107] The second aspect of this comparative example provides a preparation method of a cobalt-free cathode material precursor. The specific implementation manner is the same as that of Example 1, except that the on-line pH meter monitors at 14.0 and the ammonia concentration is 7 g / L.

[0108] The third aspect of this comparative example provides a cathode material. The specific implementation manner is the same as that of Example 1.

[0109] The fourth aspect of this comparative example provides the application of the precursor, its preparation method, and the cathode material in the preparation of a lithium battery.

[0110] Comparative Example 3

[0111] The first aspect of this comparative example provides a cobalt-free cathode material precursor, and the chemical formula of the precursor is Ni 0.55 Mn 0.45 (OH)2.

[0112] The second aspect of this comparative example provides a preparation method of a cobalt-free cathode material precursor. The specific implementation manner is the same as that of Example 1, except that the on-line pH meter monitors at 14.0 and the ammonia concentration is 2 g / L.

[0113] The third aspect of this comparative example provides a cathode material. The specific implementation manner is the same as that of Example 1.

[0114] The fourth aspect of this comparative example provides a precursor, its preparation method, and the application of the cathode material in the preparation of lithium batteries.

[0115] Performance testing

[0116] The cathode materials prepared in the above examples and comparative examples were subjected to the following tests:

[0117] Initial specific capacity test. The test method refers to GB / T 23365-2009. The actual test method: stand for 6 h, charge and discharge at 4.3 V and 0.2 C.

[0118] True density. The test method is: use a True Density Meter of MiaoZhun Scientific Instrument for sampling and then testing.

[0119] Initial specific capacity mAh / g <![CDATA[True density g / cm 3 > Example 1 175.6 4.5534 Example 2 182.6 4.5621 Example 3 169.8 4.6012 Example 4 171.6 4.5806 Example 5 169.5 4.6055 Example 6 169.8 4.5539 Example 7 172.5 4.4926 Example 8 171.6 4.5798 Example 9 166.8 4.5456 Example 10 167.6 4.5675 Example 11 174.5 4.5026 Example 12 173.6 4.5376 Example 13 174.8 4.5658 Comparative Example 1 162.3 4.6577 Comparative Example 2 158.6 4.6619 Comparative Example 3 164.9 4.6458

[0120] The cathode materials prepared in the above examples and comparative examples were subjected to rate performance testing. The specific method is as follows:

[0121] Rate test regime: First, stand for 20 minutes, charge at 0.5 C to a voltage of 4.3 V, stand for 20 minutes, discharge at 0.1 C, and the cut-off voltage is 3 V. Then charge at 0.5 C to a voltage of 4.3 V, stand for 20 minutes, discharge at 0.5 C, and the cut-off voltage is 3 V. Then charge at 0.5 C to a voltage of 4.3 V, stand for 20 minutes, discharge at 1 C, and the cut-off voltage is 3 V. Then charge at 0.5 C to a voltage of 4.3 V, stand for 20 minutes, discharge at 2 C, and the cut-off voltage is 3 V.

[0122] 0.1C 0.5C 1.0C 2.0C 0.1C / ％ 0.5C / ％ 1.0C / ％ 2.0C / ％ Example 1 177.5 166.4 157.4 145.0 106.7 100.0 94.6 87.1 Example 2 176 165.5 156.4 142 106.34 100.0 94.5 85.8 Example 3 176.4 166.7 158 144.7 105.82 100.0 94.8 86.8 Example 4 177.4 167.4 157.9 143.1 105.97 100.0 94.3 85.5 Example 5 177.9 167.7 158.6 143.3 106.08 100.0 94.6 85.5 Example 6 176.4 166.8 158.4 144.1 105.76 100.0 95.0 86.4 Example 7 177.1 168.7 160.4 146.8 104.98 100.0 95.1 87.0 Example 8 175.6 165.1 156.3 142.3 106.36 100.0 94.7 86.2 Example 9 178.4 166.5 156.3 140.8 107.15 100.0 93.9 84.6 Example 10 177.3 165.8 155.3 139.4 106.94 100.0 93.7 84.1 Example 11 177.1 167.9 158.9 144.3 105.48 100.0 94.6 85.9 Example 12 178.2 168.1 158.8 142.7 106.01 100.0 94.5 84.9 Example 13 179 169.3 160 144.8 105.73 100.0 94.5 85.5 Comparative Example 1 168.0 148.2 133.1 113.1 113.4 100.0 89.8 76.3 Comparative Example 2 156.3 122.9 107.9 89.8 127.2 100.0 87.8 73.1 Comparative Example 3 157.0 139.6 126.4 109.7 112.5 100.0 90.5 78.6

Claims

1. A cathode material, characterized in that, The preparation method of the positive electrode material includes: Sampling and uniformly mixing a lithium salt and a cobalt-free positive electrode material precursor in a molar ratio of 1:1.05, adding an additive, heating to 850 °C, holding for 10 h, cooling, roller compressing and crushing, and sieving to remove magnetism to obtain a cobalt-free positive electrode material; The lithium salt is Li2CO3, the additive is Al2O3, and the addition amount of the additive is 2000 ppm of the total weight of the lithium salt and the cobalt-free positive electrode material precursor; The chemical formula of the cobalt-free cathode material precursor is Ni 0.65 Mn 0.35 (OH)2; The preparation method of the cobalt-free positive electrode material precursor includes: While introducing oxygen as an oxidant under a nitrogen atmosphere, after adding 5 L of a bottom solution to a reaction kettle, continuously introducing an aqueous solution of 2 mol / L nickel salt and 2 mol / L manganese salt with a flow rate of 0.3 L / h and a precipitant with a flow rate of 0.1 L / h, monitoring with an on-line pH meter at 11.0, ammonia concentration of 0 g / L, continuously stirring and reacting at 45 °C for 100 h to obtain a cobalt-free positive electrode material precursor; The bottom solution is 2 mol / L ammonia water, the precipitant is 1 mol / L sodium hydroxide, the nickel salt is nickel sulfate, and the manganese salt is manganese sulfate; The flow rate of the oxidant is 0.2 mL / min, and the molar ratio of the nickel salt to the manganese salt is 1.3:0.

7.

2. The application of the positive electrode material according to claim 1 in the preparation of a lithium battery.

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