High-compaction positive electrode material precursor and preparation method thereof, positive electrode material, battery and power-related equipment

Abstract

The invention provides a high-compaction positive electrode material precursor and a preparation method thereof, a positive electrode material, a battery and electric equipment, and relates to the field of batteries. The high-compaction positive electrode material precursor comprises a first type of particles with the particle size smaller than 5 microns and a second type of particles with the particle size larger than or equal to 5 microns; the ratio of the number ratio of the first type of particles to the number ratio of the second type of particles is (10-40): 1. The preparation method of the high-compaction positive electrode material precursor comprises the step of mixing two or more precursor particles to obtain the high-compaction positive electrode material precursor. According to the high-compaction positive electrode material precursor provided by the invention, the precursors with different particle sizes are in a proper number ratio range, the filling effect of a large number of small particles on gaps of large particles is ideal, the particle size range of the small particles is proper, and relatively high compaction density is totally fed back.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a high tap density cathode material precursor, a preparation method thereof, a cathode material, a battery, and an electricity-related device. Background Art

[0002] With the development of lithium-ion batteries, there are currently various types of cathode materials applied in the market, such as lithium iron phosphate, lithium cobaltate, lithium nickel cobalt manganese oxide, etc.

[0003] Lithium-ion power batteries have been widely used in various devices due to their advantages such as high energy, high battery voltage, wide operating temperature range, and long storage life.

[0004] Currently, the main application scenario of ternary cathode materials is the power battery field, and the power battery field pays more attention to the high tap density performance index of materials.

[0005] Therefore, developing a high tap density cathode material and its precursor has become one of the research focuses. Summary of the Invention

[0006] The purpose of the present application is to provide a high tap density cathode material precursor, a preparation method thereof, a lithium-ion battery, and a lithium battery device to solve the above problems.

[0007] To achieve the above purpose, the present application adopts the following technical solutions:

[0008] A high tap density cathode material precursor includes a first type of particles with a particle size less than 5 μm and a second type of particles with a particle size greater than or equal to 5 μm;

[0009] The ratio of the quantity ratio of the first type of particles to the quantity ratio of the second type of particles is (10 - 40):1.

[0010] Optionally, the high tap density cathode material precursor satisfies at least one of the following conditions:

[0011] (1) The quantity ratio of the first type of particles is 90% - 99.9%, optionally 92 - 98%;

[0012] (2) The quantity ratio of the second type of particles is 1% - 10%, optionally 5% - 10%;

[0013] (3) The particle size of the second type of particles is 5 - 30 μm;

[0014] (4) The ratio of the quantity ratio of the first type of particles to the quantity ratio of the second type of particles is (11.5 - 22.5):1; optionally (13.5 - 18.0):1.

[0015] Optionally, in the particle size distribution test chart of the high-compaction cathode material precursor (the relationship between the particle diameters tested in the particle size distribution test chart of this application and the corresponding number density), there are a first peak and a second peak, and the first peak and the second peak satisfy at least one of the following conditions:

[0016] (5) The particle diameter corresponding to the highest number proportion of the first peak is located in the range of 1 - 5 μm, optionally 1 - 3 μm;

[0017] (6) The particle diameter corresponding to the highest number proportion of the second peak is located in the range of 6 - 20 μm, optionally 7 - 15 μm.

[0018] Optionally, the first peak and the second peak satisfy at least one of the following conditions:

[0019] (7) The ratio of the number proportion of the particles corresponding to the first peak to the number proportion of the particles corresponding to the second peak is (10 - 50):1, optionally (10 - 30):1;

[0020] (8) The ratio of the highest number proportion of the first peak to the highest number proportion of the second peak is (10 - 40):1, optionally (10 - 20):1.

[0021] Optionally, the high-compaction cathode material precursor satisfies one or more of the following conditions:

[0022] A. The compaction density of the high-compaction cathode material precursor is not less than 3.3 g / cm 3 , optionally not less than 3.6 g / cm 3 ;

[0023] B. The D50 of the high-compaction cathode material precursor is 8 - 20 μm;

[0024] C. The BET specific surface area of the high-compaction cathode material precursor is 5 - 15 m 2 / g;

[0025] D. The tapped density TD of the high-compaction cathode material precursor is not less than 2.3 g / cm 3 ;

[0026] E. The high-compaction cathode material precursor includes a nickel element-containing compound, optionally nickel cobalt manganese hydroxide.

[0027] This application also provides a preparation method of the high-compaction cathode material precursor described above, including:

[0028] Mixing two or more precursor particles to obtain the high-compaction cathode material precursor.

[0029] Optionally, the mixing includes: mixing Class A precursor particles and Class B precursor particles to obtain the high-compaction cathode material precursor;

[0030] The Class A precursor particles and the Class B precursor particles satisfy one or more of the following conditions:

[0031] (1) The mass ratio of the Class A precursor particles to the Class B precursor particles is (1.5 - 6):1;

[0032] (2) The D50 of the Class A precursor particles is 12 - 25 μm, optionally 14 - 20 μm;

[0033] (3) The Span value ((D90 - D50) / D10) of the Class A precursor particles is 0.3 - 1.5, optionally 0.3 - 0.5 or 1.0 - 1.5;

[0034] (4) The D50 of the Class B precursor particles is 1.0 - 8.0 μm, optionally 3.0 - 6.0 μm;

[0035] (5) The Span value ((D90 - D50) / D10) of the Class B precursor particles is 0.4 - 1.5, optionally 0.5 - 0.8 or 1.0 - 1.5.

[0036] This application also provides a high-compaction cathode material, the raw materials of which include the high-compaction cathode material precursor described above.

[0037] This application also provides a battery, including the high-compaction cathode material described above.

[0038] This application also provides an electricity-related device, including the battery described above.

[0039] Compared with the prior art, the beneficial effects of this application include:

[0040] For the high-compaction cathode material precursor provided by this application, by setting particles with a particle size less than 5 μm and particles with a particle size greater than or equal to 5 μm and controlling the ratio of their quantity ratios, the precursor particles of different particle sizes are within a suitable quantity ratio range, and the relatively large number of small particles has an ideal filling effect on the gaps between large particles, so that the cathode material precursor as a whole exhibits a high tap density.

[0041] For the preparation method of the high-compaction cathode material precursor provided by this application, a variety of precursor particles are mixed to obtain the high-compaction cathode material precursor, and the process is simple.

[0042] For the high-compaction cathode material provided by this application, it inherits the advantage of the high tap density of the precursor.

[0043] The battery and electricity-related equipment provided by this application have excellent electrical performance. Description of the Drawings

[0044] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as limiting the scope of this application.

[0045] Figure 1 It is the quantity density distribution diagram for Embodiments 1-5;

[0046] Figure 2 It is the proportion diagram of the quantity of different particle sizes for Embodiments 1-5;

[0047] Figure 3 It is the quantity density distribution diagram for Embodiment 2-1;

[0048] Figure 4 It is the proportion diagram of the quantity of different particle sizes for Embodiment 2-1;

[0049] Figure 5 It is the proportion diagram of the quantity of different particle sizes for Embodiment 3-1;

[0050] Figure 6 It is the proportion diagram of the quantity of different particle sizes for Embodiment 4-1;

[0051] Figure 7 It is the proportion diagram of the quantity of different particle sizes for Comparative Example 1-1;

[0052] Figure 8 It is the proportion diagram of the quantity of different particle sizes for Comparative Example 2-2. Detailed Embodiments

[0053] To better explain the technical solutions provided by this application, before the embodiments, the technical solutions will be presented as a whole as follows:

[0054] A high-compaction cathode material precursor includes a first type of particles with a particle size less than 5 μm and a second type of particles with a particle size greater than or equal to 5 μm;

[0055] The ratio of the quantity proportion of the first type of particles to the quantity proportion of the second type of particles is (10-40):1.

[0056] Optionally, the ratio of the quantity proportion of the first type of particles to the quantity proportion of the second type of particles can be 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1 or any value between (10-40):1.

[0057] In an optional embodiment, the high-compaction cathode material precursor satisfies at least one of the following conditions:

[0058] (1) The proportion of the number of the first type of particles is 90%-99.9%, optionally 92-98%;

[0059] Optionally, the proportion of the number of the first type of particles can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.9% or any value between 90%-99.9%;

[0060] (2) The proportion of the number of the second type of particles is 1%-10%, optionally 5%-10%;

[0061] Optionally, the proportion of the number of the second type of particles can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or any value between 1%-10%;

[0062] (3) The particle size of the second type of particles is 5-30 μm;

[0063] Optionally, the particle size of the second type of particles can be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm or any value between 5-30 μm;

[0064] (4) The ratio of the proportion of the number of the first type of particles to the proportion of the number of the second type of particles is (11.5-22.5):1, optionally (13.5-18.0):1.

[0065] In an optional embodiment, in the particle size distribution test chart of the high-compaction cathode material precursor, there are a first peak and a second peak, and the first peak and the second peak satisfy at least one of the following conditions:

[0066] (5) The particle size corresponding to the highest proportion of the first peak is located between 1-5 μm, optionally 1-3 μm;

[0067] (6) The particle size corresponding to the highest proportion of the second peak is located between 6-20 μm, optionally 7-15 μm.

[0068] Optionally, the particle size corresponding to the highest proportion of the first peak is located in any interval between 1-2 μm, 1-3 μm, 1-4 μm, 2-5 μm or 1-5 μm, and the particle size corresponding to the highest proportion of the second peak is located in any interval between 6-10 μm, 7-15 μm, 8-20 μm or 6-20 μm.

[0069] In an optional embodiment, the first peak and the second peak satisfy at least one of the following conditions:

[0070] (7) The ratio of the proportion of the number of particles corresponding to the first peak to the proportion of the number of particles corresponding to the second peak is (10 - 50):1, optionally (10 - 30):1;

[0071] (8) The ratio of the highest proportion of the number of the first peak to the highest proportion of the number of the second peak is (10 - 40):1, optionally (10 - 20):1.

[0072] Optionally, a bimodal distribution, where the proportion of the number of the first peak and the second peak is large, indicating that the number of small particles dominates. A relatively large number of small particles provides an ideal filling effect for the gaps between large particles, resulting in a high tap density. Moreover, with a large proportion of small particles, after mixing, it also provides the characteristics of short ion migration channels and fast migration rates for the small particles themselves, making it easy to exhibit excellent rate performance.

[0073] It should be noted that the dividing line between the first peak and the second peak is a straight line perpendicular to the abscissa at the lowest point (i.e., the inflection point) between the highest points of the two peaks.

[0074] Optionally, the ratio of the proportion of the number of secondary particles corresponding to the first peak to the proportion of the number of secondary particles corresponding to the second peak can be any value between 10:1, 20:1, 30:1, 40:1, 50:1, or (10 - 50):1, and the ratio of the highest proportion of the number of the first peak to the highest proportion of the number of the second peak can be any value between 10:1, 20:1, 30:1, 40:1, or (10 - 40):1.

[0075] In an optional embodiment, the high-tap-density cathode material precursor satisfies one or more of the following conditions:

[0076] A. The tap density of the high-tap-density cathode material precursor is not less than 3.3 g / cm 3 , optionally not less than 3.6 g / cm 3 ;

[0077] For example, the tap density of the high-tap-density cathode material precursor can be 3.3 g / cm 3 , 3.4 g / cm 3 , 3.5 g / cm 3 , 3.6 g / cm 3 , 3.7 g / cm 3 , 3.8 g / cm 3 , 3.9 g / cm 3 , 4.0 g / cm 3 or a value not less than 3.3 g / cm 3 .

[0078] A high tap density is reflected in the battery performance as an extremely high discharge specific capacity.

[0079] B. The D50 of the high tap density cathode material precursor is 8 - 20 μm;

[0080] Optionally, the D50 of the high tap density cathode material precursor can be 8 μm, 10 μm, 15 μm, 20 μm or any value between 8 - 20 μm;

[0081] C. The BET specific surface area of the high tap density cathode material precursor is 5 - 15 m 2 / g;

[0082] Optionally, the BET of the high tap density cathode material precursor can be 5 m 2 / g, 10 m 2 / g, 15 m 2 / g or any value between 5 - 15 m 2 / g;

[0083] D. The tap density TD of the high tap density cathode material precursor is not less than 2.3 g / cm 3 ;

[0084] For example, the TD of the high tap density cathode material precursor can be 2.3 g / cm 3 , 2.4 g / cm 3 , 2.5 g / cm 3 , 2.6 g / cm 3 , 2.7 g / cm 3 , 2.8 g / cm 3 , 2.9 g / cm 3 , 3.0 g / cm 3 or a value not less than 2.3 g / cm 3 ;

[0085] E. The high tap density cathode material precursor includes a nickel - containing compound, optionally nickel - cobalt - manganese hydroxide.

[0086] This application also provides a preparation method of the high tap density cathode material precursor described above, including:

[0087] Mixing two or more precursor particles to obtain the high tap density cathode material precursor.

[0088] It should be noted that the particle size of the precursor particles referred to here does not need to strictly correspond to the particle size ranges of the first - type particles and the second - type particles, and only requires that when the high tap density cathode material precursor obtained by mixing is classified according to particle size, it can meet the particle size ranges of the first - type particles and the second - type particles.

[0089] In an optional embodiment, the mixing includes: mixing Class A precursor particles and Class B precursor particles to obtain the high-compactness cathode material precursor;

[0090] The Class A precursor particles and the Class B precursor particles satisfy one or more of the following conditions:

[0091] (1) The mass ratio of the Class A precursor particles to the Class B precursor particles is (1.5 - 6):1;

[0092] (2) The D50 of the Class A precursor particles is 12 - 25 μm, optionally 14 - 20 μm;

[0093] (3) The Span of the Class A precursor particles is 0.3 - 1.5, optionally 0.3 - 0.5 or 1.0 - 1.5;

[0094] (4) The D50 of the Class B precursor particles is 1.0 - 8.0 μm, optionally 3.0 - 6.0 μm;

[0095] (5) The Span of the Class B precursor particles is 0.4 - 1.5, optionally 0.5 - 0.8 or 1.0 - 1.5.

[0096] Optionally, the mass ratio of the Class A precursor particles to the Class B precursor particles can be 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1 or any value between (1.5 - 6):1; the D50 of the Class A precursor particles can be 12 μm, 15 μm, 20 μm, 25 μm or any value between 12 - 25 μm; the Span of the Class A precursor particles can be 0.3, 0.5, 1.0, 1.5 or any value between 0.3 - 1.5; the D50 of the Class B precursor particles can be 1.0 μm, 2.0 μm, 3.0 μm, 4.0 μm, 5.0 μm, 6.0 μm, 7.0 μm, 8.0 μm or any value between 1.0 - 8.0 μm; the Span of the Class B precursor particles can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5 or any value between 0.4 - 1.5.

[0097] The present application also provides a high-compactness cathode material, the raw materials of which include the high-compactness cathode material precursor described above.

[0098] The present application also provides a battery, including the high-compactness cathode material described above.

[0099] The present application also provides an electricity-related device, including the battery described above.

[0100] The implementation scheme of the present application will be described in detail below in combination with specific embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those without specific conditions noted in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments without the manufacturer noted, they are all conventional products that can be obtained through commercial purchase.

[0101] Example 1-1

[0102] (1) Preparation of Class A particles: A metal salt solution is prepared by mixing nickel salt, cobalt salt, and manganese salt in a molar ratio of Ni:Co:Mn = 88:9:3, where the sum of the mass concentrations of metal ions is 120 g / L. Pure water, sodium hydroxide solution (mass percentage concentration of 20.0%), and ammonia water solution (mass percentage concentration of 16.4%) are added into the reaction kettle to prepare a bottom liquid with a pH value of 12.2 and an ammonia water mass concentration of 9.4 g / L. Nitrogen is introduced as a protective gas, the reaction temperature is 70 - 80 °C, the stirring speed during the reaction process is adjusted to 410 r / min, the metal salt solution is introduced at a set flow rate of 15 L / min, the flow rate of the sodium hydroxide solution is adjusted to 2.46 L / h, and the flow rate of the ammonia water is adjusted to 0.81 L / h, so that the pH in the reaction kettle is maintained between 12.1 - 12.3. When the measured slurry particle size D50 is 14 μm, the reaction is stopped. After post-treatment, the nickel-cobalt-manganese precursor: Ni 0.88 Co 0.09 Mn 0.03 (OH)2 is obtained.

[0103] (2) Preparation of Class B particles: A metal salt solution is prepared by mixing nickel salt, cobalt salt, and manganese salt in a molar ratio of Ni:Co:Mn = 79:12:9, where the sum of the mass concentrations of metal ions is 120 g / L. Pure water, sodium hydroxide solution (mass percentage concentration of 20.0%), and ammonia water solution (mass percentage concentration of 16.4%) are added into the reaction kettle to prepare a bottom liquid with a pH value of 11.92 and an ammonia water mass concentration of 6.0 g / L. Nitrogen is introduced as a protective gas, the reaction temperature is 50 - 55 °C. The stirring speed during the reaction process is adjusted to 331 r / min, the metal salt solution is introduced at a set flow rate of 10 L / min, the flow rate of the sodium hydroxide solution is adjusted to 2.16 L / h, and the flow rate of the ammonia water is adjusted to 0.78 L / h, so that the pH in the reaction kettle is maintained between 10.4 - 10.6. When the measured slurry particle size D50 is 3.8 μm, the reaction is stopped. After post-treatment, the nickel-cobalt-manganese precursor: Ni 0.79 Co 0.12 Mn 0.09 (OH)2 is obtained.

[0104] (3) Mix Class A particles and Class B particles evenly at a mass ratio of 6:4 to obtain the high-compactness cathode material precursor.

[0105] Examples 1-2 to 1-6

[0106] Examples 1-2 to 1-5: The difference from Example 1-1 is that the mass ratio of the mixture of Class A particles and Class B particles is different, and the specific ratio is shown in Table 1.

[0107] Example 1-6: The differences from Example 1-1 are: 1) For Class A particles: When the particle size D50 reaches 17.4 μm in the reaction, stop the reaction; 2) The mass ratio of the mixture of Class A particles and Class B particles is different, and the specific ratio is shown in Table 1.

[0108] Example 2-1

[0109] (1) Preparation of Class A particles: Prepare a metal salt solution by mixing nickel salt, cobalt salt, and manganese salt in a molar ratio of Ni:Co:Mn = 88:9:3, where the sum of the mass concentrations of metal ions is 120 g / L.

[0110] Step 1: Add pure water, sodium hydroxide solution (mass percentage concentration of 20.0%), and ammonia water solution (mass percentage concentration of 16.4%) into the reaction kettle to prepare a first bottom liquid with a pH value of 9-10 and an ammonia water mass concentration of 8.0 g / L; the stirring speed is 370 r / min; Pass inert gas protection to the first bottom liquid, and add the metal salt mixed solution, ammonia water, and NaOH solution into the first bottom liquid reaction kettle. The reaction temperature is 40-45 °C, with continuous feeding and discharging. During the reaction process, fine-tune the flow rates of ammonia water and NaOH solution to control the pH within the range of 9.0-9.3 and the ammonia concentration within the range of 8-9 g / L to maintain stable particle size. After the reaction is stable, prepare to receive the material to obtain a core with an average particle size D50 of 3.0 μm.

[0111] Step 2: Put the core obtained in Step 1 into a reaction kettle, and add a certain amount of pure water, sodium hydroxide solution (mass percentage concentration is 20.0%), and ammonia water solution (mass percentage concentration is 16.4%) into the reaction kettle. Stir evenly under constant temperature conditions to obtain a second bottom liquid with a pH of 12 - 13 and an ammonia water mass concentration of 8.5 g / L, and the stirring speed is 370 r / min; Pass inert gas protection to the second bottom liquid, and add the metal salt mixed solution, complexing agent, and precipitant into the second bottom liquid reaction kettle. The reaction temperature is 40 - 45 °C, with continuous feeding and discharging. During the reaction process, control the pH within the range of 12.3 - 12.5 and the ammonia concentration within the range of 8.5 - 9 g / L by finely adjusting the flow rates of the precipitant and complexing agent. Continuously add the core obtained in Step 2 to maintain the particle size stability. After the reaction is stable, prepare to receive the material to obtain an average particle size D50 of 15.4 μm. Post-treat the reaction product to obtain a precursor with the chemical formula Ni 0.88 Co 0.09 Mn 0.03 (OH)2.

[0112] (2) Preparation of Class B particles: Prepare a metal salt solution by mixing nickel salt, cobalt salt, and manganese salt according to a molar ratio of Ni:Co:Mn = 79:12:9, where the sum of the mass concentrations of metal ions is 120 g / L. Add pure water, sodium hydroxide solution (mass percentage concentration is 20.0%), and ammonia water solution (mass percentage concentration is 16.4%) into the reaction kettle to prepare a bottom liquid with a pH value of 9.2 - 9.5 and an ammonia water mass concentration of 2.5 g / L; The stirring speed is 340 r / min; Pass inert gas protection to the bottom liquid, and add the metal salt mixed solution, ammonia water, and NaOH solution into the first bottom liquid reaction kettle. The reaction temperature is 45 - 50 °C, with continuous feeding and discharging. During the reaction process, control the pH within the range of 9.1 - 9.6 and the ammonia concentration within the range of 2.3 - 2.8 g / L by finely adjusting the flow rates of ammonia water and NaOH solution to maintain the particle size stability. After the reaction is stable, prepare to receive the material to obtain an average particle size D50 of 3.4 μm. Post-treat the reaction product to obtain a precursor with the chemical formula Ni 0.79 Co 0.12 Mn 0.09 (OH)2.

[0113] (3) Mix Class A particles and Class B particles evenly according to a mass ratio of 6.5:3.5 to obtain the high-compactness cathode material precursor.

[0114] Examples 2 - 2 to 2 - 4

[0115] Examples 2 - 2 to 2 - 4: The difference from Example 2 - 1 is that the mass ratio of the mixture of Class A particles and Class B particles is different, and the specific ratio is shown in Table 1.

[0116] Examples 3-1 to 3-2

[0117] The differences from Example 2-1 are as follows: 1) The B-type particles used are the B-type particles described in Example 1-1, and 2) The mass ratio of the A-type particles to the B-type particles in the mixture is different. The specific ratios are shown in Table 1.

[0118] Examples 4-1 to 4-3

[0119] The differences from Example 1-1 are as follows: 1) The preparation method of the B-type particles used is the one described in Example 2-1, with the difference that the reaction is stopped when the particle size D50 reaches 3.38 μm, and 2) The mass ratio of the A-type particles to the B-type particles in the mixture is different. The specific ratios are shown in Table 1.

[0120] Comparative Examples 1-1 to 1-3

[0121] The differences from Example 3-1 are as follows: The mass ratio of the A-type particles to the B-type particles in the mixture is different. The specific ratios are shown in Table 1.

[0122] Comparative Examples 2-1 to 2-2

[0123] The differences from Example 1-1 are as follows: 1) The B-type particles used are the B-type particles described in Example 4-1, and 2) The mass ratio of the A-type particles to the B-type particles in the mixture is different. The specific ratios are shown in Table 1.

[0124] Comparative Examples 3 to 5

[0125] Comparative Example 3: The differences from Example 2-1 are as follows: The mass ratio of the A-type particles to the B-type particles in the mixture is different. The specific ratios are shown in Table 1.

[0126] Comparative Examples 4 to 5: The differences from Example 1-6 are as follows: The mass ratio of the A-type particles to the B-type particles in the mixture is different. The specific ratios are shown in Table 1.

[0127] Among them, the number density distribution diagram of Example 1-5 is as Figure 1 shown. The proportion of the number of different particle sizes in the number density distribution diagram of Example 1-5 is as Figure 2 shown. The number density distribution diagram of Example 2-1 is as Figure 3 shown. Figure 4 is the proportion diagram of the number of different particle sizes of Example 2-1; Figure 5 is the proportion diagram of the number of different particle sizes of Example 3-1; Figure 6 is the proportion diagram of the number of different particle sizes of Example 4-1; Figure 7 is the proportion diagram of the number of different particle sizes of Comparative Example 1-1; Figure 8 is the proportion diagram of the number of different particle sizes of Comparative Example 2-2.

[0128] The method for testing the compaction density is as follows: The compaction density is calculated using Material software and a 300 kN controlled electronic pressure testing machine. The operation steps are as follows: Place the empty mold on the test bench, pre-press it with a certain pressure, record the height at this time as h0, and zero the instrument; then weigh about 1 g of the precursor powder sample, and record the specific mass as m; put the sample into the mold, level it, place it on the test bench, set the test pressure (0.75 t), holding time and other parameters, and the measured height is h1; finally, according to the area S (132.665 mm 2 ) of the mold, the height h of the compacted sample (h = h1 - h0), and the mass m of the object, the compaction density can be calculated. Take three groups of the same sample to test the compaction density, and calculate the average value as the compaction density of the sample.

[0129] The method for testing the particle size distribution is as follows: The average particle size is obtained by testing with a Mastersizer 3000 instrument.

[0130] The operation steps are as follows: First, initialize the computer so that the light energy is between -10 and 10, and the laser is below 0.00%. Ensure that the stirrer is rotating. Modify the mode of the sample to be tested on the computer. The ultrasonic intensity is 80% and the time is 60 s. The analysis mode is Malvern 3000. The background measurement duration is 6 s, the sample measurement duration is 6 s, and the number of measurements is 3 times. The sample average value is the particle size of the sample.

[0131] The precursor data obtained from the examples and comparative examples are shown in Table 1, and the corresponding data of the particle size distribution peak are shown in Table 2:

[0132] Table 1 Precursor data obtained from examples and comparative examples

[0133]

[0134]

[0135] Table 2 Corresponding data of the particle size distribution peak for each example and comparative example

[0136]

[0137]

[0138] In the precursor product of this embodiment, the ratio of the quantity proportion of the first type of particles (particle size D < 5 μm) to the quantity proportion of the second type of particles (particle size D ≥ 5 μm) is (10 - 40):1. By controlling the ratio of their quantity proportions, the precursors with different particle sizes are within a suitable range of quantity proportions. The relatively large number of small particles has an ideal filling effect on the gaps between large particles, thus overall reflecting that the precursor of the cathode material has a high tap density. Using it to make the cathode material and assembling it into a button cell for testing, under the condition that the voltage range is 3.0 - 4.3V, the initial discharge capacity at 1C (1C = 200 mA / g) can be greater than 230 mAh / g. Among them, in some particle size distribution test diagrams, there is a bimodal distribution, and the ratio of the quantity proportion of the particles corresponding to the first peak to the quantity proportion of the particles corresponding to the second peak is (10 - 50):1. It has a high tap density and a high density of small particles, and the rate performance at 7C / 1C can be greater than 91%, with excellent high-rate performance.

[0139] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A high-compaction cathode material precursor, characterized in that, It includes a first type of particles with a particle size less than 5 μm and a second type of particles with a particle size greater than or equal to 5 μm; The ratio of the quantity proportion of the first type of particles to the quantity proportion of the second type of particles is (10 - 40):

1.

2. The high-compaction cathode material precursor according to claim 1, wherein The high-compactness cathode material precursor satisfies at least one of the following conditions: (1) The quantity proportion of the first type of particles is 90% - 99.9%, optionally 92% - 98%; (2) The quantity proportion of the second type of particles is 1% - 10%, optionally 5% - 10%; (3) The particle size of the second type of particles is 5 - 30 μm; (4) The ratio of the quantity proportion of the first type of particles to the quantity proportion of the second type of particles is (11.5 - 22.5):1, optionally (13.5 - 18.0):

1.

3. The high-compaction cathode material precursor according to claim 1 or 2, characterized in that, In the particle size distribution test chart of the high-compactness cathode material precursor, there are a first peak and a second peak, and the first peak and the second peak satisfy at least one of the following conditions: (5) The particle size corresponding to the highest quantity proportion of the first peak is located at 1 - 5 μm, optionally 1 - 3 μm; (6) The particle size corresponding to the highest quantity proportion of the second peak is located at 6 - 20 μm, optionally 7 - 15 μm.

4. The high-compaction cathode material precursor according to claim 3, wherein The first peak and the second peak satisfy at least one of the following conditions: (7) The ratio of the quantity proportion of the particles corresponding to the first peak to the quantity proportion of the particles corresponding to the second peak is (10 - 50):1, optionally (10 - 30):1; (8) The ratio of the highest quantity proportion of the first peak to the highest quantity proportion of the second peak is (10 - 40):1, optionally (10 - 20):

1.

5. The high-compaction cathode material precursor according to claim 1 or 2, characterized in that, Satisfy one or more of the following conditions: A. The tap density of the high-compaction cathode material precursor is not less than 3.3 g / cm 3 , optionally not less than 3.6 g / cm 3 ; B. The D50 of the high-compactness cathode material precursor is 8 - 20 μm; C. The BET specific surface area of the high-compaction cathode material precursor is 5-15 m 2 / g; D. The tapped density TD of the high-compaction cathode material precursor is not less than 2.3 g / cm 3 ; E. The high-compactness cathode material precursor includes a nickel element-containing compound, optionally nickel cobalt manganese hydroxide.

6. A method for preparing the high-compaction cathode material precursor according to any one of claims 1-5, characterized in that, It includes: Mix two or more types of precursor particles to obtain the high-compactness cathode material precursor.

7. The preparation method of the high-compactness cathode material precursor according to claim 6, wherein The mixing includes: mixing A-type precursor particles and B-type precursor particles to obtain the high-compactness cathode material precursor; The A-type precursor particles and the B-type precursor particles satisfy one or more of the following conditions: (1) The mass ratio of the A-type precursor particles to the B-type precursor particles is (1.5 - 6):1; (2) The D50 of the A-type precursor particles is 12 - 25 μm, optionally 14 - 20 μm; (3) The Span value of the A-type precursor particles is 0.3 - 1.5, optionally 0.3 - 0.5 or 1.0 - 1.5; (4) The D50 of the B-type precursor particles is 1.0 - 8.0 μm, optionally 3.0 - 6.0 μm; (5) The Span value of the B-type precursor particles is 0.4 - 1.5, optionally 0.5 - 0.8 or 1.0 - 1.

5.

8. A high-compaction cathode material, characterized in that, Its raw material includes the high-compactness cathode material precursor according to any one of claims 1 - 6.

9. A battery, characterized in that, It includes the high-compactness cathode material according to claim 8.

10. An electric-related device, characterized in that, It includes the battery according to claim 9.

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