Method for directly manufacturing positive electrode particles with ceramic particles and glass phase composite layer by using precursor

Abstract

The invention discloses a method for directly manufacturing positive electrode particles with ceramic particles and a glass phase composite layer by applying a precursor. The method comprises the following steps: grinding a nickel source, a manganese source, a cobalt source and a dispersion liquid to form nickel-cobalt-manganese mixed slurry; then carrying out spray drying and sintering on the nickel-cobalt-manganese mixed slurry to form a nickel-cobalt-manganese oxide precursor; mixing and grinding a lithium source, a glass phase precursor, an LLZO precursor and the dispersion liquid to form first precursor slurry; mixing the nickel-cobalt-manganese precursor and the dispersion liquid, and mixing with the first precursor slurry to form a third precursor slurry; then drying the third precursor slurry to obtain precursor powder; the precursor powder is subjected to aerobic sintering to form a plurality of nickel-cobalt-manganese particles and a plurality of LLZO particles, the glass phase precursor can form a glass phase layer to coat the outer surface of each nickel-cobalt-manganese particle, the plurality of LLZO particles can be distributed on the outer surface of each glass phase layer, and the plurality of positive electrode particles are integrally formed.

Description

Technical Field

[0001] This invention relates to the field of cathode material technology, and in particular to a method for directly manufacturing cathode particles having a composite layer of ceramic particles and glass phase using a precursor. Background Technology

[0002] A battery is mainly formed by a positive electrode and a negative electrode placed in an electrolyte. The positive electrode is formed by mixing and dispersing numerous positive electrode conductive units (positive electrode materials, such as lithium cobalt oxide) in a slurry. To increase conductivity, multiple positive electrode particles are filled into the positive electrode slurry. The material of these positive electrode particles can be selected from NCM (lithium nickel cobalt manganese oxide) or a mixture containing NCM.

[0003] Traditional cathode particles are prone to interfacial side reactions, leading to reduced cathode lifespan and low electronic conductivity, resulting in poor overall battery performance. Therefore, conventional technologies coat the cathode particles with ceramic particles such as LLZO (lithium lanthanum zirconium oxide) to increase lithium-ion conductivity, and coat the cathode particles with a glass phase layer to reduce interfacial impedance, improve powder coating properties, stabilize them in the electrolyte, and prevent interfacial side reactions. To further increase the conductivity of the slurry, carbon nanotubes and nanoscale amorphous carbon can also be added to coat the cathode particles.

[0004] The conventional method for manufacturing NCM composite cathode particles coated with ceramic particles and a glass phase layer employs a two-stage sintering process. In this process, precursors are used to pre-form NCM particles and ceramic particles, respectively. The NCM particles are then sintered with the glass phase material, resulting in a glass phase layer coating the surface of the NCM particles. Finally, the ceramic particles are mixed and stirred with the NCM particles containing the glass phase layer to form the composite cathode particle. However, this method requires two stages of sintering, which incurs significant costs and time, leading to increased manufacturing costs.

[0005] Therefore, existing technologies have shortcomings and need to be improved. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for directly manufacturing cathode particles with a composite layer of ceramic particles and glass phase using a precursor, thereby improving the production efficiency of battery materials and reducing time costs by forming cathode particles coated with a glass phase layer and ceramic particles in a one-time sintering process.

[0007] Therefore, the purpose of this invention is to solve the aforementioned problems in the prior art. This invention proposes a method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor. This method uses a nickel source, a manganese source, and a cobalt source to manufacture the nickel-cobalt-manganese precursor, resulting in a lower manufacturing cost than directly using commercially available nickel-cobalt-manganese precursors, thus reducing the overall battery material cost. Furthermore, this invention employs a wet mixing method, i.e., by adding a dispersion liquid, the lithium source, the glass phase precursor, the LLZO precursor, and the nickel-cobalt-manganese precursor are uniformly dispersed in the solution, resulting in better overall uniformity. The deposition layer formed by the glass phase precursor and the LLZO precursor on the surface of the nickel-cobalt-manganese precursor is also denser, thus forming a more complete glass phase layer and LLZO particles. This glass phase layer can prevent direct contact between the NCM particles and the electrolyte, reducing interfacial side reactions and lowering the interfacial resistance for lithium ions to enter and exit the NCM particles. These LLZO particles possess the ability to accommodate and homogenize lithium ions, and can disperse the lithium ion pathways, thus providing better lithium ion conduction. This invention utilizes a single sintering process to form the cathode particle from NCM precursor, glass phase precursor, and LLZO precursor, reducing process complexity, processing time, and production costs. The cathode particle is further coated with carbon nanotubes and nanoscale amorphous carbon, which increases electron conductivity on the cathode particle. The cathode with these cathode particles can serve as a ternary cathode.

[0008] To achieve the above objectives, this invention proposes a method for directly manufacturing cathode particles with a composite layer of ceramic particles and a glass phase using a precursor. These cathode particles are used as the cathode in solid-state or near-solid-state batteries. The method includes the following steps: Step A: Grinding a nickel source, a manganese source, a cobalt source, and a first dispersion in a grinding mill to form a nickel-cobalt-manganese mixed slurry; wherein the nickel source, manganese source, and cobalt source are salts containing nickel, manganese, and cobalt, respectively; Step B: Drying the nickel-cobalt-manganese mixed slurry (e.g., spray drying) to form... Nickel-cobalt-manganese precursor powder; then the nickel-cobalt-manganese precursor powder is placed in a first sintering furnace for atmosphere protection or oxygen sintering to form a nickel-cobalt-manganese precursor; wherein the nickel-cobalt-manganese precursor is a granular material formed by multiple particles, and the particle surface of the nickel-cobalt-manganese precursor has multiple pores; Step C: The lithium source, glass phase precursor, LLZO precursor and second dispersion are placed in a mixer for mixing and grinding to form a first precursor slurry, and the particle size of the first precursor slurry is ground to D50. (mass-median-diameter, MMD, the mass median particle size distribution) is less than 200 nm; wherein the glass phase precursor is a precursor for forming the glass phase layer; the LLZO precursor is a precursor for forming LLZO, which is used to form ceramic particles; Step D: The nickel-cobalt-manganese precursor and the third dispersion are mixed to form a second precursor slurry, and then the second precursor slurry is placed in the mixer and thoroughly stirred and mixed with the first precursor slurry to form a third precursor slurry; Step E: The third precursor slurry is dried to obtain precursor powder; wherein drying is carried out by one of the following methods: vacuum baking, reduced pressure concentration, or spray drying to quickly remove liquid, so that the glass phase precursor and the LLZO precursor precipitate from the particle surface of the nickel-cobalt-manganese precursor to form a deposition layer deposited on the particle surface of the nickel-cobalt-manganese precursor, and A precursor powder with a uniform and dense deposition layer is generated; wherein the glass phase precursor and the LLZO precursor are distributed in a continuous thin film distribution or a discontinuous distribution with island-shaped particles on the particle surface of the nickel-cobalt-manganese precursor; Step F: The precursor powder is placed in a second sintering furnace for aerobic sintering to obtain sintered powder formed by multiple cathode particles; wherein the melting point of the lithium source is lower than that of the nickel-cobalt-manganese precursor, the glass phase precursor and the LLZO precursor, so that the lithium source will melt first and mix into the deposition layer of the precursor powder, and enter the multiple pores of the nickel-cobalt-manganese precursor; then the lithium source will decompose into highly reactive lithium oxide at high temperature, and the lithium oxide will react with the nickel-cobalt-manganese precursor to form multiple NCM (lithium nickel cobalt manganese oxide) particles; at the same time, the lithium oxide will also react with the LLZO precursor to form multiple LLZO particles;Then, when the glass phase precursor melts at high temperature, a glass phase layer is formed, coating the outer surface of each NCM particle. The multiple LLZO particles are distributed on the corresponding outer surface of the glass phase layer. The NCM particles with the glass phase layer and the corresponding LLZO particles form the corresponding positive electrode particles. The glass phase layer serves to prevent direct contact between the NCM particles and the electrolyte, reducing interfacial side reactions. Simultaneously, it reduces the interfacial impedance for lithium ions to enter and exit the NCM particles, improving rate charge / discharge performance and accommodating volume changes during charge / discharge.

[0009] The features and advantages of this work will be further explained in the following description; please refer to the accompanying drawings while reading. Attached Figure Description

[0010] Figure 1 The diagram shows steps 500 to 530 of manufacturing the cathode particle in this case.

[0011] Figure 2 The flowchart shows steps 500 to 510 of manufacturing the cathode particle in this case.

[0012] Figure 3 This flowchart shows steps 520 to 550 of manufacturing the cathode particle in this case.

[0013] Figure 4 This diagram shows the steps involved in manufacturing the carbon-coated cathode particles in this case.

[0014] Figure 5 This shows an enlarged view of the structure of the positive electrode particles in this case.

[0015] Figure 6 This shows a cross-sectional view of the positive electrode particles in this case.

[0016] Figure 7 This example demonstrates the application of this case.

[0017] Figure 8 This diagram shows the structure of the positive electrode particles coated with carbon material in this case.

[0018] Figure 9 This diagram shows the structure of the nickel-cobalt-manganese precursor in this case.

[0019] Figure 10 This diagram shows a cross-sectional view of the nickel-cobalt-manganese precursor and the deposited layer in this case.

[0020] The composition includes: 10 cathode substrate, 12 cathode slurry layer, 14 cathode slurry, 20 nickel-cobalt-manganese precursor, 21 pores, 22 lithium source, 24 glassy phase precursor, 27 second precursor slurry, 28 first precursor slurry, 29 third precursor slurry, 30 carbon nanotubes, 31 precursor powder, 32 short-chain carbon nanotubes, 34 long-chain carbon nanotubes, 35 nanometer-scale amorphous carbon, 40 sintered powder, 50 nickel source, 51 deposition layer, 52 manganese source, 54 cobalt source, 58 nickel-cobalt-manganese mixed slurry, 100 cathode, 120 mill, 140 first sintering furnace, 150 mixer, 200 cathode particles, 201 NCM particles, 241 glassy phase layer, 250 second sintering furnace, 251 first dispersion, 252 second dispersion, and 253... The third dispersion consists of 261 LLZO particles and 300 carbon-coated cathode particles. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] Please refer to Figures 1 to 10 As shown, this case proposes a method for directly manufacturing cathode particles with a composite layer of ceramic particles and a glass phase using a precursor. For example... Figure 6 As shown, the positive electrode particles 200 of this invention are mainly used in the positive electrode 100 of general solid-state or solid-state batteries. The positive electrode 100 includes a positive electrode substrate 10 and a positive electrode slurry layer 12 coated on the positive electrode substrate 10. The positive electrode slurry layer 12 includes a positive electrode slurry 14 with a binder and a plurality of positive electrode particles 200. The binder is such as PVDF (polyvinylidene fluoride), PEO (polyethylene oxide), etc. The plurality of positive electrode particles 200 account for 80 wt% to 98 wt% of the weight percentage of the positive electrode slurry layer 12.

[0023] like Figure 1 As shown, the method in this case includes the following steps: Step 500: Place the nickel source 50, manganese source 52, cobalt source 54 and the first dispersion 251 into a grinding mill 120 and grind them to form a nickel-cobalt-manganese mixed slurry 58. Grind the particle size of the nickel-cobalt-manganese mixed slurry 58 to a D50 (mass-median-diameter, MMD, the mass median particle size distribution) of less than 100 nanometers.

[0024] The nickel-cobalt-manganese mixed slurry 58 may also contain metal M as a dopant, which is selected from at least one of aluminum (Al), tungsten (W), zirconium (Zr).

[0025] The nickel source 50, manganese source 52, and cobalt source 54 are salts containing nickel, manganese, and cobalt, respectively, such as oxides, acetates, carbonates, and nitrates. The nickel source 50 is selected from nickel oxide, nickel acetate, nickel carbonate, or nickel nitrate; the manganese source 52 is selected from manganese oxide, manganese acetate, manganese carbonate, or manganese nitrate; and the cobalt source 54 is selected from cobalt oxide, cobalt acetate, cobalt carbonate, or cobalt nitrate.

[0026] When the nickel-cobalt-manganese mixed slurry 58 contains the metal M, the molar ratio of the nickel source 50, the manganese source 54, the cobalt source 52, and the metal M is x:y:z:m, where 0.5≤x≤0.95; 0.05≤y≤0.3; 0.05≤z≤0.3; 0≤m≤0.05; and x+y+z+m = 1.

[0027] Step 510: The nickel-cobalt-manganese mixed slurry 58 is spray-dried to form nickel-cobalt-manganese precursor powder 60. The nickel-cobalt-manganese precursor powder 60 is then placed in a first sintering furnace 140 for atmosphere-protected sintering or oxygen-containing sintering to form nickel-cobalt-manganese precursor 20. The sintering temperature of the first sintering furnace 140 is 500℃~950℃, and the sintering time is 8 hours~16 hours. In step 510, when the temperature of the first sintering furnace 140 is raised to a specific temperature, it is held for a specific time before the temperature is further increased. The nickel-cobalt-manganese precursor is a porous spherical nickel-cobalt-manganese precursor composed of needle-like grains or nanoparticles.

[0028] Step 520: The lithium source 22, glass phase precursor 24, LLZO precursor 26, and second dispersion 252 are placed in a mixer 150 for mixing and grinding to form a first precursor slurry 28, and the particle size of the first precursor slurry 28 is ground to a D50 of less than 200 nm. In the first precursor slurry 28, the solids formed by the lithium source 22, the glass phase precursor 24, and the LLZO precursor 26 account for a weight percentage between 5 wt% and 25 wt%. The glass phase precursor 24 is a precursor for forming a glass phase layer; the LLZO precursor 26 is a precursor for forming LLZO, which is used to form the ceramic particles of this invention. The second dispersion 252 in step 520 and the first dispersion 251 in step 500 can be the same or different types of solutions.

[0029] The lithium source 22 is selected from at least one of lithium hydroxide (LiOH), lithium carbonate (Li2CO3), lithium nitrate (LiNO3), or a mixture thereof.

[0030] The glass precursor 24 is an amorphous oxide, specifically an amorphous oxide whose lithium-ion conductivity can exceed 10⁻⁵ S / cm after heat treatment. This amorphous oxide is an oxide of lithium with elements from Group IIIA, IVA, or VA, or an amorphous oxide-based solid electrolyte. For example, the oxide of lithium with elements from Group IIIA, IVA, or VA is Li₂O-ROn, where n = 1~3, and R is at least one of boron (B), aluminum (Al), silicon (Si), germanium (Ge), phosphorus (P), and arsenic (As). The amorphous oxide-based solid electrolyte is selected from amorphous perovskite-based solid electrolytes (Li-La-Ti-O, LLTO) and garnet-based solid electrolytes (e.g., Li₇La₃Zr₂O). 12 It includes at least one of LLZO, lithium phosphorus oxynitride (LiPON), and lithium titanium aluminum phosphate (LATP).

[0031] The LLZO precursor 26 is a granular material formed by multiple particles. In this case, the LLZO precursor 26 refers to all garnet solid electrolytes (such as Li7La3Zr2O) that can form a cubic crystal system (a crystal structure with a specific morphology) after co-firing with the lithium source 22. 12 The specific components of the product include oxides, hydroxides, carbonates, etc. The intermediate product formed after the specific components are coprecipitated or sintered has a structure with a distinct crystalline phase or a multi-component mixed amorphous structure.

[0032] The particle size of the LLZO precursor 26 is between 50 nm and 300 nm. When this LLZO precursor 26 is used to form the LLZO Li7La3Zr2O... 12 In this case, the LLZO precursor 26 comprises a lithium source compound (selected from lithium oxide, lithium hydroxide, lithium carbonate, etc.), a lanthanum source compound (selected from lanthanum oxide, lanthanum hydroxide, lanthanum carbonate, etc.), and a zirconium source compound (selected from zirconium oxide, zirconium hydroxide, zirconium carbonate, etc.). The LLZO precursor 26 may also contain doping elements, such as aluminum (Al), gallium (Ga), tantalum (Ta), niobium (Nb), copper (Cu), etc., with the doping element content in an equivalent ratio to lanthanum (La) not exceeding 0.25:3.

[0033] Step 530: Mix the nickel-cobalt-manganese precursor 20 with the third dispersion 253 to form a second precursor slurry 27, and then place the second precursor slurry 27 into the mixer 150 and mix it thoroughly with the first precursor slurry 28 to form a third precursor slurry 29.

[0034] The nickel-cobalt-manganese precursor 20 accounts for 5 wt% to 40 wt% of the weight of the second precursor slurry 27. The molar equivalent ratio of the nickel-cobalt-manganese precursor 20, the lithium source 22, the glass phase precursor 24, and the LLZO precursor 26 is 1.0:(1.02~1.25):(0.005~0.02):(0.005~0.02).

[0035] The solids formed by the lithium source 22, the glass phase precursor 24, the LLZO precursor 26, and the nickel-cobalt-manganese precursor 20 account for 15 wt% to 40 wt% of the weight of the third precursor slurry 29. The ratio of the weight of the nickel-cobalt-manganese precursor 20 to the total weight of the glass phase precursor 24 and the LLZO precursor 26 is greater than 20:1.

[0036] like Figure 9 As shown, the nickel-cobalt-manganese precursor 20 is a granular material formed by multiple particles, and the surface of the particles of the nickel-cobalt-manganese precursor 20 has multiple pores 21. The particle size of the nickel-cobalt-manganese precursor 20 is between 1 micrometer and 5 micrometers.

[0037] In steps 500, 520, and 530, the first, second, and third dispersions 251, 252, and 253 can be alcohol solutions or pure water, preferably ethanol or isopropanol.

[0038] Step 540: The third precursor slurry 29 is dried to obtain precursor powder 31. The drying method is selected from rapid liquid removal methods such as vacuum baking, reduced pressure concentration, and spray drying, causing the glass phase precursor 24 and the LLZO precursor 26 to precipitate from the particle surface of the nickel-cobalt-manganese precursor 20, forming a deposition layer 51 deposited on the particle surface of the nickel-cobalt-manganese precursor 20 (e.g., ...). Figure 10 As shown), a precursor powder 31 with a uniform and dense deposition layer 51 is produced.

[0039] In step 520, a buffer solution (such as ammonia or acetic acid) may be added to control the thickness and density of the deposition layer 51 formed by the glass phase precursor 24 and the LLZO precursor 26 in step 540.

[0040] In steps 520 and 530, the second and third dispersions 252 and 253 are added and mixed, which is a wet mixing process. This process can uniformly disperse the lithium source 22, the glass phase precursor 24, the LLZO precursor 26, and the nickel-cobalt-manganese precursor 20, thereby achieving better mixing uniformity and making the deposition layer 51 formed by the glass phase precursor 24 and the LLZO precursor 26 more compact.

[0041] The glass phase precursor 24 and the LLZO precursor 26 are distributed in a continuous thin film distribution pattern or a discontinuous distribution pattern with island-shaped particles on the particle surface of the nickel-cobalt-manganese precursor 20.

[0042] Step 550: The precursor powder 31 is placed in a second sintering furnace 250 for aerobic sintering. The temperature is first raised to 400°C to 700°C in a pure oxygen atmosphere and maintained for 1 to 4 hours, so that the lithium source 22 in the precursor powder 31 is completely melted and fully mixed with other substances in the precursor powder 31. Then the temperature is raised to 800°C to 1000°C and maintained for 6 to 12 hours. Finally, the temperature is naturally cooled to room temperature in a pure oxygen atmosphere to obtain sintered powder 40 formed by multiple positive electrode particles 200.

[0043] like Figure 5 and Figure 6 As shown, the lithium source 22 has a lower melting point than the nickel-cobalt-manganese precursor 20, the glass phase precursor 24, and the LLZO precursor 26. Therefore, it will melt first and mix into the deposited layer of the precursor powder 31, and enter the multiple pores 21 of the nickel-cobalt-manganese precursor 20. Then, the lithium source 22 decomposes into highly reactive lithium oxide at high temperature. The lithium oxide reacts with the nickel-cobalt-manganese precursor 20 to form multiple NCM (lithium nickel cobalt manganese oxide) particles 201. At the same time, the lithium oxide also reacts with the LLZO precursor 26 to form multiple LLZO particles 261. On the other hand, when the glass phase precursor 24 melts at high temperature, a glass phase layer 241 is formed and covers the outer surface of each NCM particle 201. The plurality of LLZO particles 261 are distributed on the outer surface of the corresponding glass phase layer 241. The NCM particle 201 having the glass phase layer 241 and the corresponding LLZO particles 261 forms the corresponding positive electrode particle 200.

[0044] The crystal structure of the glass phase layer 241 is unspecified, and the glass phase layer 241 is a continuous thin film layer covering the outer surface of the NCM particle 201.

[0045] The glass phase layer 241 is used to block the direct contact between the NCM particles 201 and the electrolyte, reducing interfacial side reactions; at the same time, it reduces the interfacial impedance of lithium ions entering and leaving the NCM particles 201, improving the rate charge and discharge performance. The glass phase layer 241 can accommodate the volume change during charge and discharge, improving the mechanical properties of the powder and reducing breakage.

[0046] like Figure 4 As shown, this case also includes the following steps: Step 560: The sintered powder 40 is mechanically pulverized and then sieved through a screen, preferably with a mesh size of 500. After sieving, the D50 particle size of the NCM particles 201 is 2 to 10 micrometers; the thickness of the glass phase layer 241 is between 20 and 100 nanometers; and the maximum radial dimension of the LLZO particles 261 is between 50 nm and 300 nm.

[0047] Step 570: Multiple carbon nanotubes 30 (CNTs) and multiple nanoscale amorphous carbon 35 are mixed with the sieved sintered powder 40 to form multiple carbon-coated cathode particles 300. Two different methods can be used for mixing the carbon material, which are described below.

[0048] The first method of mixing the carbon material involves simultaneously placing the sintered powder 40, the plurality of carbon nanotubes 30, and the plurality of nanoscale amorphous carbon 35 into a dry stirrer (such as a planetary stirrer or a drum stirrer, not shown in the figure) for mixing, thereby forming the plurality of carbon-coated cathode particles 300. Each carbon-coated cathode particle 300 includes a corresponding cathode particle 200, a corresponding plurality of carbon nanotubes 30, and a plurality of nanoscale amorphous carbon 35 coating the exterior of the corresponding cathode particle 200 (such as...). Figure 8 The mixing speed of the dry mixer is 50 rpm to 500 rpm, and the mixing time is 2 hours to 8 hours.

[0049] The second method of carbon material mixing involves first mixing the plurality of carbon nanotubes 30 and the sintered powder 40, and then adding the plurality of nanoscale amorphous carbon 35 for a second mixing to form the carbon-coated cathode particles 300. Each carbon-coated cathode particle 300 comprises a corresponding cathode particle 200, a corresponding plurality of carbon nanotubes 30, and a plurality of nanoscale amorphous carbon 35 coating the exterior of the corresponding cathode particle 200. The first and second mixing methods are either dry ball milling or wet ball milling.

[0050] The plurality of carbon nanotubes 30 include a plurality of short-chain carbon nanotubes 32 and a plurality of long-chain carbon nanotubes 34. The length of each short-chain carbon nanotube 32 is between 0.5 micrometers and 1 micrometer, and the length of each long-chain carbon nanotube 34 is between 3 micrometers and 8 micrometers. In each of the positive electrode particles 300 coated with carbon material, the weight percentage of the corresponding plurality of carbon nanotubes 30 in the corresponding positive electrode particle 200 is between 0.1 wt% and 2 wt%.

[0051] The short-chain carbon nanotubes 32 are used to bridge each LLZO particle 261 and the corresponding cathode particle 200, while the long-chain carbon nanotubes 34 are used to coat each cathode particle 200. The nanoscale amorphous carbon 35 is, for example, the amorphous carbon of the Super P conductive agent. The size of each nanoscale amorphous carbon 35 is between 20 nanometers and 100 nanometers. Each nanoscale amorphous carbon 35 fills the gaps formed by the interlacing of the plurality of carbon nanotubes 30. In each cathode particle 300 coated with carbon material, the total weight of the corresponding plurality of nanoscale amorphous carbon 35 accounts for between 0.1 wt% and 2 wt% of the weight of the corresponding cathode particle 200.

[0052] Carbon nanotubes are used to increase electronic conductivity by forming conductive bridges around the various LLZO particles 261, allowing electrons to conduct across the positive electrode particles 200. The carbon nanotubes 30 are randomly distributed on the surface of their respective positive electrode particles 200. Because carbon nanotubes have extremely high conductivity, electrons can conduct between the different LLZO particles 261 and the positive electrode particles 200 via the carbon nanotubes 30, thus increasing the overall conductivity of the positive electrode 100.

[0053] The multiple nanoscale amorphous carbon 35 and the multiple carbon nanotubes 30 both serve as conductive agents. Because each nanoscale amorphous carbon 35 is in the form of particles, while each carbon nanotube 30 is in the form of elongated strips, gaps will be formed between the multiple carbon nanotubes 30 crisscrossing on the positive electrode particle 200. These gaps cannot conduct current. Therefore, by adding the corresponding nanoscale amorphous carbon 35 into these gaps, the charge can be conducted between different carbon nanotubes 30 through the bridging of the nanoscale amorphous carbon 35, further increasing the current transfer efficiency.

[0054] The advantages of this invention are that it uses nickel, manganese, and cobalt sources to manufacture the nickel-cobalt-manganese precursor, resulting in lower manufacturing costs compared to directly using commercially available nickel-cobalt-manganese precursors, thus reducing overall battery material costs. Furthermore, this invention employs a wet mixing method, where a dispersion liquid is added to ensure uniform dispersion of the lithium source, the glass phase precursor, the LLZO precursor, and the nickel-cobalt-manganese precursor in the solution. This results in better overall uniformity, and the deposition layer formed by the glass phase precursor and the LLZO precursor on the surface of the nickel-cobalt-manganese precursor is denser, leading to a more complete glass phase layer and LLZO particles. This glass phase layer prevents direct contact between the NCM particles and the electrolyte, reducing interfacial side reactions and lowering the interfacial resistance for lithium ions to enter and exit the NCM particles. The LLZO particles have the ability to accommodate and homogenize lithium ions and disperse lithium ion pathways, providing better lithium ion transport. This invention utilizes a single sintering process to form the cathode particle from NCM precursors, glass phase precursors, and LLZO precursors, reducing process complexity, processing time, and production costs. The cathode particle is further coated with carbon nanotubes and nanoscale amorphous carbon, increasing electron conductivity. The cathode with this cathode particle can then serve as a ternary cathode.

[0055] The above detailed description is a specific description of a feasible embodiment of the present invention. However, the embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the spirit of the present invention should be included in the patent scope of this case.

Claims

1. A method for directly manufacturing cathode particles with a composite layer of ceramic particles and a glass phase using a precursor, characterized in that, The positive electrode particle is used as the positive electrode in a solid-state or solid-state-like battery, and the method includes the following steps: Step A: The nickel source, manganese source, cobalt source and the first dispersion are placed in a grinding mill and ground to form a nickel-cobalt-manganese mixed slurry; wherein the nickel source, the manganese source and the cobalt source are salts containing nickel, manganese and cobalt elements, respectively; Step B: The nickel-cobalt-manganese mixture slurry is dried to form nickel-cobalt-manganese precursor powder; then the nickel-cobalt-manganese precursor powder is placed in a first sintering furnace for atmosphere protection or oxygen sintering to form nickel-cobalt-manganese precursor; wherein the nickel-cobalt-manganese precursor is a granular material formed by multiple particles, and the surface of the particles of the nickel-cobalt-manganese precursor has multiple pores. Step C: The lithium source, glass phase precursor, LLZO precursor, and second dispersion are placed in a mixer for mixing and grinding to form a first precursor slurry, and the particle size of the first precursor slurry is ground to a D50 of less than 200 nm; wherein the glass phase precursor is a precursor for forming a glass phase layer; the LLZO precursor is a precursor for forming LLZO, which is used to form ceramic particles; wherein LLZO is lithium lanthanum zirconium oxide. Step D: Mix the nickel-cobalt-manganese precursor and the third dispersion to form a second precursor slurry, and then place the second precursor slurry into the mixer and mix it thoroughly with the first precursor slurry to form a third precursor slurry; Step E: The third precursor slurry is dried to obtain precursor powder; wherein the drying is carried out by one of the following methods: vacuum baking, reduced pressure concentration, or spray drying to quickly remove liquid, so that the glass phase precursor and the LLZO precursor precipitate from the particle surface of the nickel cobalt manganese precursor to form a deposition layer deposited on the particle surface of the nickel cobalt manganese precursor, thereby producing precursor powder with a uniform and dense deposition layer; wherein the distribution pattern of the glass phase precursor and the LLZO precursor on the particle surface of the nickel cobalt manganese precursor is a continuous thin film distribution pattern or a discontinuous distribution pattern with island-like particles; Step F: The precursor powder is placed in a second sintering furnace for aerobic sintering to obtain sintered powder forming multiple cathode particles; wherein the melting point of the lithium source is lower than that of the nickel-cobalt-manganese precursor, the glass phase precursor, and the LLZO precursor, so that the lithium source will melt first and mix into the deposition layer of the precursor powder, and enter the multiple pores of the nickel-cobalt-manganese precursor; then the lithium source decomposes into highly reactive lithium oxide at high temperature, and the lithium oxide reacts with the nickel-cobalt-manganese precursor to form multiple NCM particles; at the same time, the lithium oxide also reacts with the LLZO precursor to form multiple LLZO particles; then, when the glass phase precursor melts at high temperature, a glass phase layer is formed to coat the outer surface of each NCM particle, and the multiple LLZO particles are distributed on the outer surface of the corresponding glass phase layer, and the NCM particles with the glass phase layer and the corresponding LLZO particles form the corresponding cathode particles; wherein, NCM is lithium nickel-cobalt-manganese oxide. The glass phase layer is used to block direct contact between the NCM particles and the electrolyte, reducing interfacial side reactions; at the same time, it reduces the interfacial impedance for lithium ions to enter and exit the NCM particles, improves the rate charge and discharge performance, and accommodates the volume changes during charge and discharge.

2. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The glass phase precursor is an amorphous oxide, which, after heat treatment, exhibits a lithium-ion conductivity higher than 10. -5 S / cm non-crystalline oxide; wherein the crystal structure of the glass phase layer is of an unspecified form, and the glass phase layer is a continuous thin film layer covering the outer surface of the NCM particles.

3. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 2, characterized in that, The non-crystalline oxide is an amorphous oxide-based solid electrolyte.

4. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 3, characterized in that, The amorphous oxide-based solid electrolyte is selected from at least one of the following: amorphous perovskite-based solid electrolyte, garnet-based solid electrolyte, lithium-phosphorus-oxygen-nitride, and lithium titanium aluminum phosphate.

5. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, In step A, the particle size of the nickel-cobalt-manganese mixed slurry is ground to a D50 of less than 100 nanometers.

6. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The nickel-cobalt-manganese mixed slurry also contains metal M as a dopant, which is selected from at least one of aluminum, tungsten, and zirconium.

7. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The nickel source, the manganese source, and the cobalt source are salts containing nickel, manganese, and cobalt, respectively, and the salts are selected from at least one of oxides, acetates, carbonates, and nitrates.

8. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The nickel source is selected from nickel oxide, nickel acetate, nickel carbonate, and nickel nitrate; the manganese source is selected from manganese oxide, manganese acetate, manganese carbonate, and manganese nitrate; and the cobalt source is selected from cobalt oxide, cobalt acetate, cobalt carbonate, and cobalt nitrate.

9. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 6, characterized in that, The molar ratio of the nickel source, manganese source, cobalt source, and metal M is x:y:z:m, where 0.5≤x≤0.95; 0.05≤y≤0.3; 0.05≤z≤0.3; 0≤m≤0.05; and x+y+z+m = 1.

10. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, In step B, the sintering temperature of the first sintering furnace is 500℃~950℃, and the sintering time is 8 hours~16 hours. In step B, when the temperature of the first sintering furnace is raised to a specific temperature, it is held for a specific period of time before the temperature is raised further.

11. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, In the first precursor slurry, the solids formed by the lithium source, the glass phase precursor, and the LLZO precursor constitute between 5 wt% and 25 wt% of the weight of the first precursor slurry. In the third precursor slurry, the solids formed by the lithium source, the glass phase precursor, the LLZO precursor, and the nickel-cobalt-manganese precursor account for 15 wt% to 40 wt% of the weight of the third precursor slurry. The ratio of "the weight of the nickel-cobalt-manganese precursor" to "the total weight of the glass phase precursor and the LLZO precursor" is greater than 20:1; The particle size of the nickel-cobalt-manganese precursor is between 1 micrometer and 5 micrometers; the particle size of the LLZO precursor is between 50 nm and 300 nm. The nickel-cobalt-manganese precursor accounts for 5 wt% to 40 wt% of the weight of the second precursor slurry. The first, second, and third dispersions are respectively alcohol solutions or pure water solutions.

12. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, In step C, a buffer solution is added to control the thickness and density of the deposition layer formed by the glass phase precursor and the LLZO precursor in step E.

13. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The molar equivalent ratio of the nickel-cobalt-manganese precursor, the lithium source, the glass phase precursor, and the LLZO precursor is 1.0:(1.02~1.25):(0.005~0.02):(0.005~0.02).

14. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The nickel-cobalt-manganese precursor is a porous spherical nickel-cobalt-manganese precursor composed of needle-like grains.

15. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The lithium source is selected from at least one of lithium hydroxide, lithium carbonate, lithium nitrate, or a mixture thereof.

16. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, The LLZO precursor is a granular material formed by multiple particles. The LLZO precursor refers to all specific components that can form a cubic garnet solid electrolyte after co-firing with the lithium source. These specific components include oxides, hydroxides, and carbonates. The intermediate products formed after the co-precipitation or sintering steps of these specific components have a structure with obvious crystalline phases or a multi-component mixed amorphous structure.

17. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 16, characterized in that, The garnet solid electrolyte is Li7La3Zr2O. 12 .

18. The method for directly manufacturing cathode particles having a composite layer of ceramic particles and glass phase using a precursor as described in claim 17, characterized in that, The LLZO precursor comprises a lithium source compound, a lanthanum source compound, and a zirconium source compound; the lithium source compound is selected from at least one of lithium oxide, lithium hydroxide, and lithium carbonate; the lanthanum source compound is selected from at least one of lanthanum oxide, lanthanum hydroxide, and lanthanum carbonate; and the zirconium source compound is selected from at least one of zirconium oxide, zirconium hydroxide, and zirconium carbonate.

19. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, In step F, the sintering process involves first heating the powder to 400°C to 700°C in a pure oxygen atmosphere and maintaining this temperature for 1 to 4 hours, so that the lithium source in the precursor powder is completely melted and fully mixed with other substances in the precursor powder. Then, the temperature is raised to 800°C to 1000°C and maintained for 6 to 12 hours. Finally, the powder is allowed to cool naturally to room temperature in a pure oxygen atmosphere to obtain the sintered powder.

20. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 1, characterized in that, It also includes the following steps: Step G: The sintered powder is mechanically pulverized and then sieved through a sieve.

21. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 20, characterized in that, After sieving, the D50 particle size of the NCM particles is 2 to 10 micrometers; the thickness of the glass phase layer is between 20 and 100 nanometers; and the maximum radial size of the LLZO particles is between 50 and 300 nm.

22. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 20, characterized in that, It also includes the following steps: Step H: Mixing multiple carbon nanotubes and multiple nanoscale amorphous carbons with the sintered powder after sieving to form multiple carbon-coated cathode particles.

23. The method for directly manufacturing cathode particles with a ceramic particle and glass phase composite layer using a precursor as described in claim 22, characterized in that, The carbon nanotubes comprise multiple short-chain carbon nanotubes and multiple long-chain carbon nanotubes. The length of each short-chain carbon nanotube is between 0.5 micrometers and 1 micrometer, and the length of each long-chain carbon nanotube is between 3 micrometers and 8 micrometers. The short-chain carbon nanotubes are used to bridge each LLZO particle and the corresponding cathode particle. The long-chain carbon nanotubes are used to coat the cathode particle. The size of the nanoscale amorphous carbon is between 20 nanometers and 100 nanometers. Each nanoscale amorphous carbon system fills the gaps formed by the interlacing of the multiple carbon nanotubes.

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