CN-121983562-A - Composite solid-state positive electrode material, preparation method thereof, lithium ion battery and electric equipment

CN121983562ACN 121983562 ACN121983562 ACN 121983562ACN-121983562-A

Abstract

The application provides a composite solid-state positive electrode material, a preparation method thereof, a lithium ion battery and electric equipment, and relates to the field of lithium ion batteries. The composite solid-state positive electrode material comprises a positive electrode material and an organic elastic sphere which are uniformly mixed, wherein the positive electrode material comprises a core, a metal compound coating layer and a boride coating layer which are sequentially arranged on the surface of the core, the core comprises a ternary positive electrode material, and raw materials of the organic elastic sphere comprise hydrocarbon derivative monomers, alkenyl monomers, emulsifying agents, oxidizing agents and solvents. The organic elastic sphere solves the problem of unsmooth interface contact caused by volume change in the charge and discharge process of the solid-state battery anode material, the organic elastic sphere inner core is rigid to a certain extent, the outer shell is high in elasticity, and the organic elastic sphere can be used as a rigid framework support and can also be used as an elastic support to be always in tight contact with the surface of the anode material.

Inventors

BAI LIXIONG
PENG WEIJIA
ZHOU XINDONG
ZHOU LAI
ZHU JIAN
HU LIUQUAN
ZHANG JINJIN
HU HAISHI

Assignees

湖南长远锂科新能源有限公司
金驰能源材料有限公司
五矿新能源材料(湖南)股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. The composite solid positive electrode material is characterized by comprising a positive electrode material and an organic elastic sphere which are uniformly mixed; the positive electrode material comprises a core, and a metal compound coating layer and a boride coating layer which are sequentially arranged on the surface of the core, wherein the core comprises a ternary positive electrode material; The raw materials of the organic elastic sphere comprise hydrocarbon derivative monomers, alkenyl monomers, emulsifying agents, oxidizing agents and solvents; The hydrocarbon derivative monomer comprises at least one of aniline, pyrrole, fluorene, caprolactam, aminocaproic acid, hexamethylenediamine, adipic acid, acrylic acid, methacrylic acid, methyl methacrylate, butyl acrylate, lactic acid, glycolic acid, caprolactone, terephthalic acid and ethylene glycol; the mass of the organic elastic sphere accounts for 500-20000ppm of the mass of the positive electrode material; The Dv50 of the composite solid-state positive electrode material is 1.8-3.2 mu m; the Dv50 of the organic elastic sphere is 0.1-5 μm.
2. The composite solid state cathode material of claim 1, wherein at least one of the following conditions is satisfied: (1) The general structural formula of the inner core is Li a Ni x Co y Mn z M w O 2 , wherein, a is more than or equal to 1.02 and less than or equal to 1.2,0.6, x is more than or equal to 1 and 0 y is more than or equal to 0.4, z is more than or equal to 0 and less than or equal to 0.4, and z is more than or equal to 0 and less than or equal to 0w is less than or equal to 0.03, x+y+z+w=1, and M comprises at least one of Zr, sr, Y, sb, al, W, ta, B, mg, ca, ti, mo and Nb; (2) The primary particles of the composite solid-state positive electrode material have a particle size of 0.8-1.5 mu m and a BET of 0.8-1.6 m 2 /g; (3) The Young modulus of the organic elastic sphere is 0.06-100 MPa, and the hardness is 1-250 MPa; (4) The raw materials of the metal compound coating layer comprise at least one of ammonium tungstate, tungsten trioxide, manganese carbonate, manganese oxide, manganous oxide, lithium tungstate, molybdenum trioxide, ammonium molybdate, titanium dioxide, cobaltosic oxide, cobalt oxyhydroxide, cobaltous oxide, aluminum hydroxide, aluminum sulfate, magnesium oxide, magnesium hydroxide, niobium pentoxide, niobic acid, lanthanum oxide, antimony oxide, cerium oxide, tellurium oxide, lithium niobate, yttrium oxide, calcium oxide, lithium titanate, aluminum phosphate, lithium phosphate, cobalt phosphate and aluminum fluoride; (5) The boride coating layer is prepared from at least one of boric acid, zirconium boride, lithium borate, boron oxide, lithium thioborate, boron nitride, lithium tetraborate, lithium metaborate, lithium tetraborate, titanium diboride, calcium hexaboride, li 2 B 12 H 12 、LiBH 4 、Li 3 BPO 6 , boron trifluoride, boron trichloride, sodium borohydride, zinc borate, borax, boron carbide, liBa (B 3 O 5 ) 3 , triethylboron, diborane, phenylboric acid and carborane.
3. The composite solid state positive electrode material according to claim 2, wherein in the structural general formula Li a Ni x Co y Mn z M w O 2 of the positive electrode material, a is 1.05-1.15,0.6-x is 1, and m includes at least one of Zr, al, W, sr, ti and Nb.
4. The composite solid state positive electrode material according to claim 1, wherein at least one of (1) the alkenyl monomer comprises at least one of ethylene, propylene, vinyl chloride, styrene, vinyl acetate, N-vinyl pyrrolidone, butadiene, isoprene, tetrafluoroethylene, ethylene glycol dimethacrylate; (2) The emulsifier comprises at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate, cetyltrimethylammonium bromide, tween-80, methacrylate, n-butanol, hexadecane, ammonium ether sulfate and polyvinyl alcohol; (3) The oxidant comprises at least one of ammonium persulfate, feCl 3 , potassium persulfate, ammonium ferric sulfate, copper chloride and sodium bisulfate; (4) The solvent comprises at least one of water, ethanol, HCl solution, toluene, cyclohexane, N-dimethylformamide, tetrahydrofuran and acetonitrile; (5) The mass ratio of the emulsifier to the hydrocarbon derivative monomer is 0.0005-0.005:1; (6) The molar ratio of the oxidant to the hydrocarbon derivative monomer is 0.7-4:1; (7) The molar ratio of the alkenyl monomer to the hydrocarbon derivative monomer is 0.05-4:1.
5. A method of preparing a composite solid state positive electrode material according to any one of claims 1 to 4, comprising: Carrying out first mixing, copolymerization and drying on hydrocarbon derivative monomers, alkenyl monomers, emulsifying agents, oxidizing agents and solvents to obtain organic elastic particle balls; And (3) carrying out second mixing and heat treatment on the anode material and the organic elastic particle balls in an inert atmosphere to obtain the composite solid anode material.
6. The method for preparing the composite solid-state cathode material according to claim 5, wherein the preparation of the cathode material comprises the steps of carrying out third mixing and first sintering on nickel cobalt manganese hydroxide, lithium salt and an M source in an oxygen-containing atmosphere to obtain a primary sintered product; Fourth mixing and second sintering are carried out on the primary sintering product and the metal compound in an oxygen-containing atmosphere to obtain a secondary sintering product; And fifth mixing the secondary sintering product and boride, and third sintering.
7. The method of preparing a composite solid state cathode material according to claim 6, wherein at least one of the following conditions is satisfied: (1) The lithium salt comprises at least one of lithium carbonate, lithium hydroxide, lithium oxide, lithium sulfide, lithium acetate and methyl lithium; (2) The M source comprises at least one of an oxide, a hydroxide, a nitrate and a carbonate containing M; (3) The mass of the metal compound accounts for 500-15000ppm of the mass of the primary sintering product; (4) The mass of the boride accounts for 500-2000ppm of the mass of the secondary sintering product; (5) The rotating speed of the third mixing is 300-1900rpm, and the time is 10-60min; (6) The first sintering comprises a fourth sintering and a fifth sintering which are sequentially carried out, wherein the temperature rising rate of the fourth sintering is 1-10 ℃ per minute, the terminal temperature is 250-550 ℃ and the time is 1-16 hours, the temperature rising rate of the fifth sintering is 1-8 ℃ per minute, the terminal temperature is 500-1000 ℃ and the time is 4-24 hours, and the oxygen content value is 90% -100%; (7) The cooling speed of the first sintering is 1-8 ℃ per minute, the oxygen-containing atmosphere comprises air and/or oxygen, and the gas flow rate of the oxygen-containing atmosphere is 8-30m 3 per hour; (8) Before the fourth mixing, crushing the primary sintering product, wherein the particle size of the crushed primary sintering product is 100-500 meshes; (9) The temperature rising rate of the second sintering is 1-8 ℃ per minute, the end point temperature is 550-750 ℃, the time is 4-24 hours, the cooling rate is 1-8 ℃ per minute, the oxygen-containing atmosphere comprises air and/or oxygen, the gas flow rate of the oxygen-containing atmosphere is 5-30m 3 per hour, and the oxygen content value is 90% -100%; (10) The temperature rising rate of the third sintering is 1-8 ℃ per minute, the end point temperature is 200-350 ℃ and the time is 1-24 hours, the atmosphere comprises an oxygen-containing atmosphere and/or an inert atmosphere, the oxygen-containing atmosphere comprises air and/or oxygen, the gas flow rate of the oxygen-containing atmosphere is 5-30m 3 per hour, the oxygen content value is 90-100%, and the inert atmosphere comprises at least one of argon, nitrogen and helium; (11) After the copolymerization reaction, water washing and centrifugation are also carried out, wherein the water washing temperature is 2-15 ℃, the time is 0.5-10min, the material-water ratio is 0.4-2:1, the rotational speed of centrifugation is 15HZ-50HZ, and the time is 5-60 min.
8. The method of preparing a composite solid state cathode material according to claim 5, wherein at least one of the following conditions is satisfied: (1) The copolymerization reaction is also carried out by ultrasonic, and the frequency of the ultrasonic is 10-80Hz; (2) The temperature of the copolymerization reaction is minus 5-90 ℃ and the time is 1-6h; (3) The heating rate of the heat treatment is 1-10 ℃ per minute, the end point temperature is 100-400 ℃, the time is 1-24h, and the cooling speed is 1-8 ℃ per minute.
9. A lithium ion battery comprising the composite solid state cathode material of any one of claims 1-4.
10. A powered device comprising the lithium-ion battery of claim 9.

Description

Composite solid-state positive electrode material, preparation method thereof, lithium ion battery and electric equipment Technical Field The application relates to the field of lithium ion batteries, in particular to a composite solid positive electrode material, a preparation method thereof, a lithium ion battery and electric equipment. Background With the increasing urgent demands of new energy automobiles and energy storage systems for high energy density and high safety batteries, the solid-state batteries are considered as the core development direction of the next-generation electrochemical energy storage technology by virtue of the intrinsic safety of the solid-state batteries due to the adoption of nonflammable solid-state electrolytes and the high energy density advantage caused by the compatibility with a metallic lithium negative electrode. As a key component of a solid-state battery, the structure and interfacial properties of the positive electrode material directly determine the overall performance of the battery. However, the current positive electrode material for solid-state batteries still faces serious technical challenges in practical application, and mainly shows two major aspects of solid-solid interface contact failure and performance attenuation under low external pressure. On the one hand, unlike conventional liquid batteries in which the electrode material is sufficiently impregnated with the electrolyte, point-to-point solid-solid contact is formed between the rigid positive electrode particles and the solid electrolyte in solid state batteries. The contact mode is extremely easy to generate gaps due to volume expansion and contraction of materials or insufficient assembly pressure, so that conduction of lithium ions at an interface is blocked, and interface impedance is obviously increased. On the other hand, to maintain limited solid-solid contact, solid-state batteries typically need to operate at high external stack pressures (tens to hundreds of megapascals), but this is severely inconsistent with the actual packaging and application scenario of the cell. Under the working condition of low pressure or no pressure, interface contact deterioration is aggravated, the utilization rate of the active material is drastically reduced, and the capacity of the battery is rapidly attenuated and the cycle life is shortened. These problems severely restrict the progress of solid-state batteries from laboratories toward industrialization. Therefore, how to improve the interfacial compatibility of the positive electrode material in a solid system and improve the structural stability and electrochemical performance under low pressure by optimizing the structural design of the positive electrode material has become a key technical problem to be solved in the art. Disclosure of Invention The application aims to provide a composite solid-state positive electrode material, a preparation method thereof, a lithium ion battery and electric equipment, so as to solve the problems. To achieve the above object, a first aspect of the present application provides a composite solid cathode material, including a cathode material and an organic elastic sphere uniformly mixed; the positive electrode material comprises a core, and a metal compound coating layer and a boride coating layer which are sequentially arranged on the surface of the core, wherein the core comprises a ternary positive electrode material; The raw materials of the organic elastic sphere comprise hydrocarbon derivative monomers, alkenyl monomers, emulsifying agents, oxidizing agents and solvents; The hydrocarbon derivative monomer comprises at least one of aniline, pyrrole, fluorene, caprolactam, aminocaproic acid, hexamethylenediamine, adipic acid, acrylic acid, methacrylic acid, methyl methacrylate, butyl acrylate, lactic acid, glycolic acid, caprolactone, terephthalic acid and ethylene glycol; the mass of the organic elastic sphere accounts for 500-20000ppm of the mass of the positive electrode material; The Dv50 of the composite solid-state positive electrode material is 1.8-3.2 mu m; the Dv50 of the organic elastic sphere is 0.1-5 μm. Optionally, the composite solid state positive electrode material meets at least one of the following conditions: (1) The general structural formula of the inner core is Li aNixCoyMnzMwO2, wherein, a is more than or equal to 1.02 and less than or equal to 1.2,0.6, x is more than or equal to 1 and 0 y is more than or equal to 0.4, z is more than or equal to 0 and less than or equal to 0.4, and z is more than or equal to 0 and less than or equal to 0 w is less than or equal to 0.03, x+y+z+w=1, and M comprises at least one of Zr, sr, Y, sb, al, W, ta, mg, ca, ti, mo, nb and B; (2) The primary particles of the composite solid-state positive electrode material have a particle size of 0.8-1.5 mu m and a BET of 0.8-1.6 m 2/g; (3) The Young modulus of the organic elastic sphere is 0.06-100 MPa, and the hardnes