A nanoscale positive electrode material precursor, a preparation method and application thereof

Abstract

The application discloses a nanoscale positive electrode material precursor and a preparation method and application thereof. The nanoscale positive electrode material precursor is prepared by using a spray pyrolysis device, and the spray pyrolysis device comprises a pyrolysis furnace, a nozzle arranged at the top of a hearth of the pyrolysis furnace, and a product outlet arranged at the bottom of the pyrolysis furnace; the pyrolysis furnace is divided into an upper temperature zone, a middle temperature zone and a lower temperature zone from top to bottom, and the temperature zones are independently controlled; the preparation method comprises the following steps: spraying a mixed metal salt solution through the nozzle, atomizing the liquid drops into the pyrolysis furnace for spray pyrolysis, controlling the temperature t1 of the upper temperature zone, the temperature t2 of the middle temperature zone and the temperature t3 of the lower temperature zone in the order of t1 < t2 < t3, and obtaining the nanoscale positive electrode material precursor after the spray pyrolysis. The positive electrode material prepared by using the nanoscale positive electrode material precursor can improve the contact between the positive electrode and the solid-state electrolyte, greatly improves the conductivity and the lithium ion transmission rate, and improves the performance of the solid-state battery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and relates to a nanoscale positive electrode material precursor and a preparation method and application thereof. BACKGROUND

[0002] As a simple and efficient energy storage system, lithium ion batteries have been highly valued at all levels of modern energy technology development. However, due to the use of organic electrolyte, the traditional liquid battery has the problems of toxicity and flammability. Moreover, lithium dendrites penetrate the separator to cause internal short circuit of the battery, and there are safety hazards such as flammability and explosiveness. Therefore, replacing the electrolyte and separator in the traditional lithium ion battery with a solid-state electrolyte to develop a safe and excellent performance low-cost all-solid-state battery has become a major challenge in the field of energy today.

[0003] The main problem of the solid-state battery is the interface contact problem, and the positive electrode and the solid-state electrolyte cannot be in good contact, thereby affecting the ion transmission. Therefore, it is very important to prepare a nanoscale positive electrode material precursor to facilitate the contact between the positive electrode and the solid-state electrolyte.

[0004] At present, most enterprises adopt the coprecipitation method to prepare the precursor, for example, CN116253368A, CN107706364A and CN115215388A all adopt the coprecipitation method to prepare the positive electrode material precursor. However, the coprecipitation method has high energy consumption, low yield, and generates a large amount of wastewater, and the prepared precursor has large particle size. It is not conducive to the good contact between the positive electrode and the solid-state electrolyte in the solid-state battery.

[0005] Therefore, it is a technical problem to be solved at present to provide a nanoscale positive electrode material precursor, which can improve the contact between the positive electrode and the solid-state electrolyte when applied to the solid-state battery. SUMMARY

[0006] In view of the above technical problems existing in the prior art, the purpose of the present application is to provide a nanoscale positive electrode material precursor and a preparation method and application thereof.

[0007] In the present application, the "nanoscale" in the nanoscale positive electrode material precursor refers to the size of the secondary particles of the positive electrode material precursor being <100 nm.

[0008] To achieve the above purpose, the present application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a preparation method of a nanoscale positive electrode material precursor, which adopts a spray pyrolysis device to prepare a nanoscale all-solid-state battery positive electrode material, wherein the spray pyrolysis device comprises a pyrolysis furnace, and a spray head is arranged at the top of the hearth of the pyrolysis furnace; the pyrolysis furnace is divided into an upper temperature zone, a middle temperature zone and a lower temperature zone from top to bottom, and the temperature zones are independently controlled.

[0010] The preparation method comprises the following steps:

[0011] The mixed metal salt solution is sprayed through a nozzle, and the atomized droplets are sprayed into a pyrolysis furnace for spray pyrolysis, the temperature t1 of the upper temperature zone is controlled to be lower than the temperature t2 of the middle temperature zone, and the temperature t3 of the lower temperature zone, and the nano-scale positive electrode material precursor is obtained after spray pyrolysis.

[0012] The method of the present application can obtain the nano-scale positive electrode material precursor by using the spray pyrolysis method, the spray from the top successively passes through the upper temperature zone, the middle temperature zone and the lower temperature zone under the action of gravity, and the temperature of the spray pyrolysis is increased, so that the nano-scale positive electrode material precursor can be obtained. Since the particle size of the positive electrode material precursor is small, the positive electrode material prepared by using the positive electrode material precursor can improve the contact between the positive electrode and the solid-state electrolyte, greatly improve the conductivity and lithium ion transmission rate, improve the material activity and capacity, and improve the performance of the solid-state battery.

[0013] The method of the present application simplifies the production process, the preparation method is pollution-free, the preparation time is short, the yield is large, the cost is low, and the method is suitable for large-scale production. Moreover, the particle size of the positive electrode material precursor prepared is small, and the particle size distribution is narrow. Moreover, the preparation method of the present application is suitable for doping the nano-scale positive electrode material precursor, and the doping is easy and the element distribution uniformity is good.

[0014] In the present application, the upper temperature zone, the middle temperature zone and the lower temperature zone are interconnected regions, each region is independently temperature-controlled, and the temperature of each region refers to the temperature of the center position of the corresponding region. In practice, the temperature of the center position of the corresponding region can be tested by a temperature sensor.

[0015] The following is a preferred technical solution of the present application, but is not a limitation on the technical solutions provided by the present application. Through the following preferred technical solution, the technical purpose and beneficial effects of the present application can be better achieved and realized.

[0016] Preferably, t2-t1 is 200℃-300℃, for example, it can be 200℃, 220℃, 240℃, 260℃, 280℃ or 300℃, etc.

[0017] Preferably, t3-t2 is 200℃-400℃, for example, it can be 200℃, 220℃, 240℃, 260℃, 280℃, 300℃, 325℃, 350℃, 375℃ or 400℃, etc.

[0018] By limiting the difference between the temperatures of adjacent regions, the particle size of the nano-scale positive electrode material precursor can be further reduced.

[0019] Preferably, the temperature t1 of the upper temperature zone is 400-500℃, for example, it can be 400℃, 420℃, 450℃, 460℃, 480℃ or 500℃, etc.

[0020] Preferably, the temperature t2 of the middle temperature zone is 700-800℃, for example, it can be 700℃, 720℃, 725℃, 750℃, 760℃, 770℃, 780℃ or 800℃, etc.

[0021] Preferably, the temperature t3 of the lower temperature zone is 1000-1300℃, for example, it can be 1000℃, 1050℃, 1100℃, 1150℃, 1200℃, 1250℃ or 1300℃, etc.

[0022] Preferably, the height ratio of the upper temperature zone, the middle temperature zone and the lower temperature zone is (1-1.5):(2-4):(1-1.5), wherein the height of the upper temperature zone is selected from the range of "1-1.5", for example, it can be 1, 1.1, 1.2, 1.3, 1.4 or 1.5, etc.; the height of the middle temperature zone is selected from the range of "2-4", for example, it can be 2, 2.2, 2.5, 2.6, 2.7, 2.8, 3, 3.3, 3.5, 3.6, 3.8 or 4, etc.; the height of the lower temperature zone is selected from the range of "1-1.5", for example, it can be 1, 1.1, 1.2, 1.3, 1.4 or 1.5, etc.

[0023] By limiting the temperature t1 of the upper temperature zone, the temperature t2 of the middle temperature zone and the temperature t3 of the lower temperature zone within the above range, and controlling the height ratio of the upper temperature zone, the middle temperature zone and the lower temperature zone, it is more conducive to reduce the particle size of the nanoscale positive electrode material precursor.

[0024] Preferably, the mixed metal salt solution is a nickel-cobalt-manganese ternary mixed salt solution, and the concentration of the mixed metal salt solution is 100-150g / L, for example, it can be 100g / L, 105g / L, 110g / L, 115g / L, 120g / L, 125g / L, 130g / L, 135g / L, 140g / L, 145g / L or 150g / L, etc.

[0025] In one embodiment, the nickel-cobalt-manganese ternary mixed salt solution is obtained by dissolving nickel salt, cobalt salt and manganese salt in a solvent. The present application does not make specific limitation on the types of nickel salt, cobalt salt and manganese salt, including but not limited to at least one of sulfate, nitrate, chloride or nitrate, and the selection of nickel salt, cobalt salt and manganese salt is independent of each other and does not affect each other.

[0026] Preferably, the spray amount of the spray head is 50 mL / min to 100 mL / min, for example, it can be 50 mL / min, 55 mL / min, 60 mL / min, 65 mL / min, 70 mL / min, 75 mL / min, 80 mL / min, 85 mL / min, 90 mL / min, 95 mL / min or 100 mL / min, etc.

[0027] Preferably, the angle of the spray head is 30° to 120°, for example, it can be 30°, 40°, 45°, 50°, 60°, 70°, 80°, 90°, 95°, 100°, 110° or 120°, etc. In the present application, the angle of the spray head refers to the maximum coverage angle of the mist sprayed by the spray head. Among them, the direction of the spray head is towards the straight down. If the angle of the spray head is too small, the sprayed droplets are too large, and the calcination is not complete; if the angle of the spray head is too large, it is easy to stick to the pipe wall.

[0028] Preferably, under the action of pressure, the mixed metal salt solution enters the spray head to be sprayed, and the pressure of the feed is 0.2 MPa to 0.6 MPa, for example, it can be 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa or 0.6 MPa, etc.

[0029] The spray pyrolysis device further comprises an air compressor, the air compressor is connected with the liquid storage bottle and the spray head respectively, the liquid storage bottle is used for containing the mixed metal salt solution, a first valve is arranged on the pipeline between the air compressor and the liquid storage bottle, and a second valve is arranged on the pipeline between the air compressor and the spray head. By adjusting the first valve and the second valve, the atomization degree of the mixed metal salt solution can be adjusted. Preferably, during the spray pyrolysis process, the pressure in the hearth is -0.1 MPa to -0.6 MPa, for example, it can be -0.1 MPa, -0.2 MPa, -0.3 MPa, -0.4 MPa, -0.5 MPa or -0.6 MPa, etc. The reason and benefit of such arrangement is that it can ensure good flowability of the material, avoid local deposition of the material, and fully react. If the negative pressure in the hearth is too large, it is easy to cause insufficient calcination time and not fully react to obtain oxides; if the negative pressure in the hearth is too small, firstly, the material will be deposited at the bottom of the pipe and blocked, which needs to stop the machine to dredge, affecting the yield and cost, and secondly, the material remaining at the bottom will be heated for a long time, and the electrical performance will be reduced.

[0030] Preferably, the time of spray pyrolysis is 5 s to 10 s, for example, it can be 5 s, 6 s, 7 s, 8 s, 9 s or 10 s.

[0031] In this invention, the spray pyrolysis time refers to the total time from the start time to the end time, where the start time is the time when the mixed metal salt solution is sprayed from the nozzle, and the end time is the time when the nanoscale cathode material precursor reaches the product outlet. The spray pyrolysis time here is not the total continuous production time.

[0032] In a second aspect, the present invention provides a nanoscale cathode material precursor prepared by the method described in the first aspect, wherein the primary particle size of the nanoscale cathode material precursor is in the range of 3 nm to 7 nm, and the secondary particle size is in the range of 30 nm to 70 nm.

[0033] As an example, the primary particle size can be 3nm, 4nm, 5nm, 6nm, or 7nm, etc.; the secondary particle size can be 30nm, 32nm, 33nm, 35nm, 36nm, 38nm, 40nm, 43nm, 46nm, 48nm, 50nm, 52nm, 55nm, 57nm, 60nm, 62nm, 65nm, 67nm, 68nm, or 70nm, etc.

[0034] Thirdly, the present invention provides a cathode material, which is prepared using the nanoscale cathode material precursor described in the second aspect.

[0035] Fourthly, the present invention provides a method for preparing a cathode material as described in the third aspect, the method comprising the following steps:

[0036] The cathode material is obtained by mixing the nanoscale cathode material precursor with lithium salt and then calcining it.

[0037] The calcination includes: a first calcination, followed by a second calcination after the product of the first calcination is compressed into tablets;

[0038] Preferably, the temperature of the first calcination is 400℃ to 500℃, for example, it can be 400℃, 425℃, 430℃, 435℃, 440℃, 460℃, 470℃, 480℃, 490℃ or 500℃.

[0039] Preferably, the calcination time is 3h to 6h, for example, it can be 3h, 3.5h, 4h, 4.5h, 5h, 5.5h or 6h.

[0040] Preferably, the temperature of the secondary calcination is 800℃~950℃, for example, it can be 800℃, 825℃, 850℃, 870℃, 880℃, 900℃, 915℃, 930℃, 940℃ or 950℃, etc.

[0041] Preferably, the secondary calcination time is 8h-14h, for example, it can be 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h or 14h, etc.

[0042] Preferably, the secondary calcination product is quenched after the secondary calcination is completed.

[0043] In a fifth aspect, the present application provides a full solid-state battery, wherein the full solid-state battery comprises the positive electrode material of the third aspect.

[0044] In an embodiment, the full solid-state battery comprises a positive electrode, a solid-state electrolyte layer and a negative electrode, wherein the positive electrode comprises a positive electrode material, a solid-state electrolyte and a conductive agent.

[0045] In an embodiment, the present application provides a preparation method of a full solid-state battery, comprising the following steps:

[0046] In an atmosphere of protective gas, the mixed positive electrode powder comprising a positive electrode material, a first solid-state electrolyte and a conductive agent is uniformly distributed on the bottom of a mold, then a second solid-state electrolyte powder is added on the mixed positive electrode powder, and then a negative electrode material is uniformly distributed on the second solid-state electrolyte powder, pressure is applied to the upper and lower ends of the mold and fixed, thereby obtaining a full solid-state battery.

[0047] In an embodiment, the diameter of the mold is 8mm-15mm, for example, it can be 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm or 15mm, etc. The amount of the mixed positive electrode powder is 5mg-10mg, for example, it can be 5g, 5.5g, 6g, 7g, 7.5g, 8g, 8.5g, 9g or 10g, etc.

[0048] In an embodiment, the mass ratio of the mixed positive electrode powder, the first solid-state electrolyte and the negative electrode material is (5-10):(70-90):(20-40), wherein the selection range of the mixed positive electrode powder is "5-10", for example, it can be 5, 5.5, 6, 7, 7.5, 8, 8.5, 9 or 10, etc.; the selection range of the first solid-state electrolyte is "70-90", for example, it can be 70, 71, 72, 73, 75, 76, 78, 80, 82, 83, 85, 86, 88 or 90, etc.; the selection range of the negative electrode material is "20-40", for example, it can be 20, 21, 22, 23, 25, 26, 27, 29, 30, 32, 33, 35, 36, 38 or 40, etc.

[0049] In an embodiment, the negative electrode material is a LiIn alloy thin film with a molar ratio of In to Li of 3:1.

[0050] In one embodiment, the magnitude of the applied pressure is 2T-4T, for example, it can be 2T, 2.2T, 2.4T, 2.5T, 2.6T, 2.8T, 3T, 3.3T, 3.5T, 3.7T, 3.8T or 4T, etc.

[0051] The numerical range described in the present application includes not only the point values listed above, but also any point values between the above numerical ranges that are not listed, and the present application does not exhaustively list the specific point values included in the range for the sake of brevity and simplicity.

[0052] Compared with the prior art, the present application has the following beneficial effects:

[0053] (1) The method of the present application prepares a nanoscale positive electrode material precursor by using a spray pyrolysis method. The spray from the top passes through the upper temperature zone, the middle temperature zone and the lower temperature zone in turn under the action of gravity, and the temperature of the spray pyrolysis is increasing, so that a nanoscale positive electrode material precursor can be obtained. Since the particle size of the positive electrode material precursor is small, the positive electrode material prepared by using it can improve the contact between the positive electrode and the solid-state electrolyte when applied to a solid-state battery, greatly improve the conductivity and lithium ion transmission rate, improve the material activity and capacity, and improve the performance of the solid-state battery.

[0054] (2) The method of the present application simplifies the production process, is pollution-free, has short preparation time, large yield, low cost and is suitable for large-scale production. Moreover, the prepared positive electrode material precursor has small particle size and narrow particle size distribution. Moreover, the preparation method of the present application is suitable for doping the nanoscale positive electrode material precursor, and the doping is easy and the element distribution uniformity is good. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 is a structural schematic diagram of a spray pyrolysis device used in an embodiment of the present application.

[0056] Figure 2 is a scanning diagram of the nanoscale positive electrode material precursor prepared in Example 1. DETAILED DESCRIPTION

[0057] The technical solutions of the present application will be further described below by combining the drawings and through specific embodiments.

[0058] The specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0059] Example 1

[0060] This embodiment provides a preparation method of a nanoscale positive electrode material precursor, which uses a spray pyrolysis device to prepare a nanoscale full solid-state battery positive electrode material, such as Figure 1As shown, the spray pyrolysis device comprises a pyrolysis furnace 3, a hearth 4 is arranged in the pyrolysis furnace 3, a spray head 9 is arranged at the top of the hearth 4, and a product outlet is arranged at the bottom of the pyrolysis furnace 3; the pyrolysis furnace is divided into an upper temperature zone A, a middle temperature zone B and a lower temperature zone C from top to bottom, the height ratio of the upper temperature zone, the middle temperature zone and the lower temperature zone is 1:2:1, the upper temperature zone A and the middle temperature zone B are heated by electricity, and the lower temperature zone is heated by natural gas;

[0061] The spray pyrolysis device further comprises an air compressor 1, the air compressor 1 is connected with a liquid storage bottle 2 and the spray head 9 respectively, the liquid storage bottle 2 is used for containing a mixed metal salt solution, a first valve is arranged on the pipeline of the air compressor 1 and the liquid storage bottle 2, a second valve is arranged on the pipeline of the air compressor 1 and the spray head 9, and the atomization degree of the mixed metal salt solution can be adjusted by adjusting the first valve and the second valve.

[0062] The spray pyrolysis device further comprises a cyclone separator 5, a collection bottle 6, a blowing and suction dual-purpose substation 7 and a tail gas treatment device 8, the inlet of the cyclone separator 5 is communicated with the product outlet, the outlet of the cyclone separator 5 is connected with the collection bottle 6, the tail gas treatment device 8 is connected with the inlet of the cyclone separator 5, and the blowing and suction dual-purpose fan 7 is arranged on the connecting pipeline of the tail gas treatment device 8 and the cyclone separator 5.

[0063] The preparation method comprises the following steps:

[0064] A mixed nickel-cobalt-manganese ternary salt solution (nickel, cobalt and manganese are all derived from sulfate, and the molar ratio of nickel, cobalt and manganese is 95:4:1) with a concentration of 150 g / L is poured into the liquid storage bottle 2 and uniformly mixed, under the action of pressure, the ternary mixed salt solution in the liquid storage bottle 2 is atomized into small droplets by the spray head 9 and sprayed into the hearth 4 of the pyrolysis furnace 3, the feeding pressure is 0.3 MPa, the angle of the spray head is 30℃, the spray amount is 80 mL / min, the pressure in the pyrolysis furnace is-0.3 MPa, the temperature of the upper temperature zone A is 450℃, the temperature of the middle temperature zone B is 700℃, and the temperature of the lower temperature zone C is 1300℃, the atomized droplets are rapidly dehydrated, pyrolysis and drying reactions occur, the product is generated, reaches the cyclone separator 5 under the action of the fan and is sampled to the collection bottle 6, and the ternary precursor oxide is obtained, that is, the nanoscale positive electrode material precursor is obtained.

[0065] Figure 2 It is a scanning diagram of the nanoscale positive electrode material precursor prepared in Example 1, and it can be seen from the diagram that the primary particle size of the positive electrode material precursor is in the range of 3 nm to 7 nm, and the secondary particle size is in the range of 30 nm to 70 nm.

[0066] The embodiment also provides a positive electrode material, and a preparation method thereof comprises the following steps: mixing the nanoscale positive electrode material precursor and lithium carbonate in a molar ratio of Li:M (M is a metal element in the nanoscale positive electrode material precursor) = 1.05, and calcining the mixture at 450 DEG C for 5h in an air atmosphere; pressing the obtained sintered product into a compact and dense sheet, and then sintering the sheet at 900 DEG C for 11h; and immediately quenching the sintered product by using liquid nitrogen after the sintering, so that the positive electrode material is obtained.

[0067] Example 2

[0068] The difference between the embodiment and example 1 is that, in the preparation process of the nanoscale positive electrode material precursor, the feeding pressure is 0.5 MPa, and the pressure in the pyrolysis furnace is -0.5 MPa.

[0069] Example 3

[0070] The difference between the embodiment and example 1 is that, in the preparation process of the nanoscale positive electrode material precursor, the temperature of the upper temperature zone of the pyrolysis furnace is 400 DEG C, the temperature of the middle temperature zone is 700 DEG C, and the temperature of the lower temperature zone is 1000 DEG C.

[0071] Example 4

[0072] The difference between the embodiment and example 1 is that, in the preparation process of the nanoscale positive electrode material precursor, the nickel, cobalt and manganese are all derived from acetate.

[0073] Example 5

[0074] The difference between the embodiment and example 1 is that, in the preparation process of the nanoscale positive electrode material precursor, the angle of the nozzle is 60 DEG.

[0075] Example 6

[0076] The difference between the embodiment and example 1 is that, in the preparation process of the nanoscale positive electrode material precursor, the angle of the nozzle is 60 DEG.

[0077] The concentration of the nickel-cobalt-manganese ternary mixed salt solution (nickel, cobalt and manganese are all derived from sulfate, and the molar ratio of nickel, cobalt and manganese is 95:4:1) is 110 g / L, and the solution is poured into the storage bottle 2 and mixed uniformly. Under the action of pressure, the ternary mixed salt solution in the storage bottle 2 is atomized into small droplets by the nozzle 9 and sprayed into the hearth 4 of the pyrolysis furnace 3. The feeding pressure is 0.5 MPa, the angle of the nozzle is 45 DEG, the spraying amount is 55 mL / min, the pressure in the pyrolysis furnace is -0.5 MPa, the temperature of the upper temperature zone A is 500 DEG C, the temperature of the middle temperature zone B is 800 DEG C, and the temperature of the lower temperature zone C is 1200 DEG C. The atomized droplets are rapidly dehydrated, and pyrolysis and drying reactions occur to generate products. Under the action of the fan, the products reach the cyclone separator 5 for sampling, and the samples are collected into the collection bottle 6, so that the ternary precursor oxide, i.e. the nanoscale positive electrode material precursor, is obtained.

[0078] Example 7

[0079] The difference from Example 1 is that the angle of the spray head is 20°.

[0080] Comparative Example 1

[0081] The difference from Example 1 is that the temperature of the upper temperature zone, the middle temperature zone and the lower temperature zone is all 700℃.

[0082] Comparative Example 2

[0083] The difference from Example 1 is that the temperature of the upper temperature zone, the middle temperature zone and the lower temperature zone is all 1300℃.

[0084] Comparative Example 3

[0085] The difference from Example 1 is that the temperature of the upper temperature zone, the middle temperature zone and the lower temperature zone is all 1300℃, 700℃ and 450℃, and the spray head atomization occurs at the bottom of the pyrolysis furnace, and the sampling and sample collection are carried out at the top of the pyrolysis furnace.

[0086] The positive electrode material prepared by using Examples 1-6 and Comparative Examples 1-3 is assembled into a full solid-state battery, and the method is as follows:

[0087] Under an argon atmosphere, 8 mg of mixed positive electrode powder (the mixed positive electrode powder is composed of a positive electrode material, Li3InCl6 and Super P, and Li3InCl6 and Super P are purchased) is evenly distributed at the bottom of a full solid-state mold with an inner diameter of 10 mm made of PTFE, then 80 mg of Li6PS5Cl powder (purchased) is added on top of the mixed positive electrode powder, then 30 mg of negative electrode material (the negative electrode material is a LiIn alloy thin film with a molar ratio of In to Li of 3:1, purchased) is evenly distributed on top of the Li6PS5Cl powder, and finally a pressure of 3T is applied to the upper and lower ends of the full solid-state mold and fixed, thereby assembling a lithium-rich full solid-state battery.

[0088] Performance test:

[0089] The test is performed using a blue light test system, and after 50 cycles at a voltage range of 3.6-4.2V and a rate of 0.1C, the capacity retention rate of the full solid-state battery is calculated, and the calculation formula is = the discharge capacity after 50 cycles / the first discharge capacity x 100%.

[0090] The results are shown in Table 1.

[0091] Table 1

[0092]

[0093]

[0094] As shown in Table 1, the prepared positive electrode material by using the nanoscale positive electrode material precursor of the application can improve the contact between the positive electrode and the solid-state electrolyte, greatly improve the conductivity and lithium ion transmission rate, improve the material activity and capacity, and improve the performance of the solid-state battery.

[0095] Meanwhile, as compared with Example 1 and Example 7, it is known that if the angle of the spray head is too small, the sprayed droplets are too large, resulting in incomplete calcination and reducing the electrochemical performance of the material.

[0096] As compared with Example 1 and Comparative Example 1-2, it is known that if the temperature of the three temperature zones is the same, the quality of the positive electrode material precursor is reduced, which is not conducive to the electrochemical performance of the battery.

[0097] As compared with Example 1 and Comparative Example 3, it is known that if the material is sprayed from the bottom, the material stays in the furnace for a long time, and the continuous high temperature can cause serious lithium-nickel mixing, and the performance of the positive electrode material is reduced.

[0098] The applicant declares that the detailed method of the application is illustrated by the above examples, but the application is not limited to the above detailed method, that is, it does not mean that the application must rely on the above detailed method to be implemented. It should be understood by those skilled in the art that any improvement of the application, equivalent replacement of each raw material of the product of the application, addition of auxiliary ingredients, selection of specific methods, etc. fall within the protection scope and disclosure scope of the application.

Claims

1. A method for preparing a nanoscale positive electrode material precursor, characterized in that, The preparation method comprises the following steps: The mixed metal salt solution is sprayed through the nozzle, and the atomized droplets enter the pyrolysis furnace for spray pyrolysis, the temperature t1 of the upper temperature zone is controlled to be lower than the temperature t2 of the middle temperature zone, and the temperature t3 of the lower temperature zone, and the nanoscale positive electrode material precursor is obtained after spray pyrolysis. The temperature t1 of the upper temperature zone is 400-500 DEG C. The temperature t2 of the middle temperature zone is 700-800 DEG C. The temperature t3 of the lower temperature zone is 1000-1300 DEG C. The height ratio of the upper temperature zone, the middle temperature zone and the lower temperature zone is (1-1.5):(2-4):(1-1.5). The primary particle size of the nanoscale positive electrode material precursor prepared by the preparation method is in the range of 3-7 nm, and the secondary particle size is in the range of 30-70 nm. During the spray pyrolysis, the pressure in the furnace is-0.1-0.6 MPa. t2-t1 is 200-300 DEG C.

2. The production method according to claim 1, characterized by, t3-t2 is 200-400 DEG C.

3. The preparation method according to claim 1, characterized in that, The mixed metal salt solution is a nickel-cobalt-manganese ternary mixed salt solution, and the concentration of the mixed metal salt solution is 100-150 g / L.

4. The method of claim 1, wherein, The spray amount of the nozzle is 50-100 mL / min.

5. The preparation method according to claim 1, characterized in that, The angle of the nozzle is 30-120 DEG.

6. The method of claim 1, wherein, Under the action of pressure, the mixed metal salt solution enters the nozzle to be sprayed, and the pressure of the feed is 0.2-0.6 MPa.

7. The preparation method according to claim 1, characterized in that, The spray pyrolysis device further comprises an air compressor, the air compressor is connected with the liquid storage bottle and the nozzle respectively, the liquid storage bottle is used for containing the mixed metal salt solution, a first valve is arranged on the pipeline of the air compressor and the liquid storage bottle, a second valve is arranged on the pipeline of the air compressor and the nozzle, and the atomization degree of the mixed metal salt solution can be adjusted by adjusting the first valve and the second valve.

8. The method of claim 1, wherein, The spray pyrolysis time is 5-10 s.

9. The method of claim 1, wherein, The positive electrode material is prepared by using the nanoscale positive electrode material precursor prepared by the preparation method of any one of claims 1-9.

10. A positive electrode material, characterized in that, The preparation method comprises the following steps:

11. A method of producing the positive electrode material according to claim 10, characterized by, The nanoscale positive electrode material precursor is mixed with lithium salt, and then calcined to obtain the positive electrode material. The calcination comprises: primary calcination, and secondary calcination after tabletting the product of the primary calcination.

12. The method of claim 11, wherein, The temperature of the primary calcination is 400-500 DEG C.

13. The method of claim 12, wherein, The time of the primary calcination is 3-6 h.

14. The method of claim 12, wherein, The temperature of the secondary calcination is 800-950 DEG C.

15. The method of claim 12, wherein, The time of the secondary calcination is 8-14 h.

16. The method of claim 12, wherein, The product of the secondary calcination is quenched after the secondary calcination is completed.

17. The method of claim 12, wherein, The full solid-state battery comprises the positive electrode material of claim 10.

18. An all-solid battery, characterized by, ​

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