WO2023122926A1 - 三元前驱体材料及其制备方法和应用 - Google Patents

三元前驱体材料及其制备方法和应用 Download PDF

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WO2023122926A1
WO2023122926A1 PCT/CN2021/141873 CN2021141873W WO2023122926A1 WO 2023122926 A1 WO2023122926 A1 WO 2023122926A1 CN 2021141873 W CN2021141873 W CN 2021141873W WO 2023122926 A1 WO2023122926 A1 WO 2023122926A1
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ternary precursor
precursor material
ternary
positive electrode
ammonia water
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PCT/CN2021/141873
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English (en)
French (fr)
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沈重亨
吴奇
桓书星
陈强
柳娜
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宁德时代新能源科技股份有限公司
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Priority to EP21960114.3A priority Critical patent/EP4231384A4/en
Priority to CN202180096545.5A priority patent/CN117121225A/zh
Priority to PCT/CN2021/141873 priority patent/WO2023122926A1/zh
Priority to US18/140,637 priority patent/US20230278886A1/en
Publication of WO2023122926A1 publication Critical patent/WO2023122926A1/zh

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    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
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Definitions

  • the present application relates to the technical field of secondary batteries, in particular to a ternary precursor material and its preparation method and application.
  • secondary batteries are widely used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, as well as electric tools, electric bicycles, electric motorcycles, electric vehicles, Military equipment, aerospace and other fields.
  • energy storage power systems such as hydraulic, thermal, wind and solar power stations
  • electric tools electric bicycles, electric motorcycles, electric vehicles, Military equipment, aerospace and other fields.
  • the wide application of secondary batteries has led to higher and higher requirements for the overall performance of batteries. More and more application scenarios require power batteries to have both high gram capacity and good charge and discharge characteristics.
  • the positive active material has an important influence on the improvement of the energy density of the secondary battery.
  • the high-nickel ternary positive electrode active material has a relatively high gram capacity, so it is expected to become the next-generation mainstream positive electrode active material for secondary batteries.
  • the structural stability of high-nickel positive electrode active materials is getting worse, which in turn affects the performance of secondary batteries.
  • the purpose of this application is to provide a ternary precursor material for the deficiencies of the prior art.
  • the present application also provides a preparation method of the ternary precursor material and a positive electrode active material, a secondary battery, a battery module, and a battery pack using the ternary precursor material.
  • the ternary precursor material provided by this application creatively introduces stacking fault rate and fragmentation strength as parameters for synthesis guidelines, and the positive active material sintered by using the precursor material can take into account higher gram capacity and cycle performance performance.
  • the first aspect of the present application provides a ternary precursor material, including an inner core and an outer shell, wherein (1) the molecular formula of the inner core is Ni x Co y Mn 1-xy (OH) 2 ⁇ a , Wherein: 0.8 ⁇ x ⁇ 1.0, 0 ⁇ y ⁇ 0.2, 0 ⁇ a ⁇ 0.2; the shell contains doping elements; (2) the deformation stacking fault rate f D of the ternary precursor material is ⁇ 4%.
  • the ternary precursor material described in the present application wherein the deformation stacking fault rate f D ⁇ 4%, can greatly stabilize the coordination atoms in the center of the tetrahedron, suppress the formation of vacancies, and ensure the actual stoichiometric ratio and transition metal valence It is stable, promotes the order and structural stability of high-nickel ternary cathode materials, and improves cycle performance; at the same time, the high nickel content in the core of the core-shell structure design of the precursor is very conducive to the gram capacity of the cathode material after sintering.
  • the concentrated doping elements can not only protect the surface of the active material from the corrosion of electrolyte side reaction products and improve the high-temperature cycle performance, but also serve as an excellent Li + conductor to improve the kinetic performance.
  • the fragmentation rate of the particles of the ternary precursor material under a pressure of 1 ton is ⁇ 50%; optionally ⁇ 25%.
  • the fragmentation rate of the particles of the material after compression is further limited, so that the obtained ternary precursor material has high mechanical strength, which is beneficial to suppress the high mechanical strength after sintering.
  • the cracking of nickel ternary cathode material under high temperature cycle improves cycle performance.
  • the doping element is selected from one or more of tungsten, antimony, tantalum, molybdenum, yttrium and magnesium; and/or the mass fraction of the doping element is 1000-8000ppm, Optionally, 2000-6000ppm; and/or, the doping element is tungsten element, preferably doped in the form of tungsten oxide.
  • the doping element of the shell and the mass fraction of the doping element are further defined, and the doping of the element in the shell can suppress the 101 crystal plane of the ternary precursor material
  • the growth can promote the growth of the 001 crystal plane of the ternary precursor material under high temperature sintering, which is helpful to improve the gram capacity of the positive electrode material after sintering.
  • the diameter of the inner core is 2 ⁇ m ⁇ 9 ⁇ m; and/or, the thickness of the outer shell is 0.5 ⁇ m ⁇ 4 ⁇ m.
  • ternary precursor material described in this application its core diameter and shell thickness are further defined, which is helpful for sintering a high-nickel ternary cathode material with high gram capacity and compatibility with the compressive strength of powder.
  • the particle size Dv50 of the ternary precursor material is 3 ⁇ m to 17 ⁇ m, preferably 6 ⁇ m to 10 ⁇ m; and/or the particle size SPAN value of the ternary precursor material is ⁇ 0.65, preferably ⁇ 0.45.
  • the ternary precursor material described in this application its particle size is also limited, which is conducive to sintering a high-nickel ternary positive electrode material with high compaction density, and is beneficial to the gram capacity of the positive electrode material after sintering. Furthermore, its particle size distribution is also limited, which is beneficial to improve the uniformity of lithium mixed in the high-nickel ternary cathode material after sintering, and can ensure the uniformity of physical and chemical properties; at the same time, there are almost no fine particles and micropowders, which can help Inhibits gas production and particle fragmentation at high temperatures.
  • the BET of the ternary precursor material is 4m 2 /g-16m 2 /g, preferably 8m 2 /g-12m 2 /g.
  • the BET of the ternary precursor material is further defined, which is helpful for sintering a high-nickel ternary cathode material with high gram capacity and surface chemical stability.
  • the intensity ratio of the 001 crystal plane diffraction peak to the 101 crystal plane diffraction peak of the ternary precursor material is 0.6-1.2, preferably 0.9-1.1.
  • the ratio of the intensity of the 001 crystal plane diffraction peak to the 101 crystal plane diffraction peak of the ternary precursor material is further defined, which is helpful for sintering a higher isotropic High nickel ternary cathode material.
  • the primary particle aspect ratio of the ternary precursor material is 2-8.
  • the aspect ratio of the doping elements of the ternary precursor material is further defined, so that the uniform doping in the outer shell is beneficial to enhance the stability of the surface structure and the stacking order of the sheets Doping elements can improve the cycle performance of the sintered high-nickel ternary cathode material.
  • the second aspect of the present application provides a method for preparing a ternary precursor material, wherein the method includes the following steps:
  • S1 Provide mixed salt solution, lye, ammonia water, and salt solution of doping elements, wherein the mixed salt solution contains soluble nickel salt, cobalt salt and manganese salt;
  • the ternary precursor material includes an inner core and an outer shell, and the molecular formula of the inner core is Ni x Co y Mn 1-xy (OH) 2 ⁇ a , wherein: 0.8 ⁇ x ⁇ 1.0, 0 ⁇ y ⁇ 0.2, 0 ⁇ a ⁇ 0.2; the shell contains doping elements; the deformation stacking fault rate f D of the ternary precursor material is ⁇ 4%.
  • the pH is 9.5-10.5
  • the working concentration of the ammonia water is 0.6-1 mol/L, optionally 0.65-0.75 mol/L;
  • the reaction temperature is 65-85° C.; and/or the stirring speed is 150-350 rpm.
  • the pH is 9.5-10.5, and the working concentration of the ammonia water is 0.65-0.75 mol/L.
  • the preparation method of the present application By adopting the preparation method of the present application, an excellent high-nickel ternary positive electrode material with a core-shell structure can be obtained, and the difference and content of components in the core-shell can be controlled to achieve the required high capacity and high structural stability.
  • the method of the present application has two steps of nucleation and nucleation growth in the S2 step, which can synthesize a radially distributed shell structure on the core, and can significantly improve the cycle performance of the sintered high-nickel ternary cathode material. Further, by controlling the working concentration of ammonia water in the S2 step of the present application, the deformation stacking fault rate and fragmentation degree of the ternary precursor material are effectively reduced.
  • the third aspect of the present application provides a positive electrode active material, comprising the ternary precursor material; or the ternary precursor material prepared by the method.
  • the Li/Me molar ratio is 0.9-1.1, and Me is nickel, cobalt, manganese.
  • a fourth aspect of the present application provides a secondary battery, including the positive electrode active material.
  • a fifth aspect of the present application provides a battery module, including the secondary battery.
  • a sixth aspect of the present application provides a battery pack, including the secondary battery or the battery module.
  • a seventh aspect of the present application provides an electrical device, including at least one of the secondary battery, the battery module, and the battery pack.
  • the battery module, battery pack and electric device of the present application include the secondary battery provided by the present application, and thus have at least the same advantages as the secondary battery.
  • FIG. 1 is a schematic diagram of an embodiment of a secondary battery of the present application.
  • FIG. 2 is an exploded schematic diagram of an embodiment of the secondary battery of the present application.
  • Fig. 3 is a schematic diagram of an embodiment of the battery module of the present application.
  • Fig. 4 is a schematic diagram of an embodiment of the battery pack of the present application.
  • FIG. 5 is an exploded view of FIG. 4 .
  • FIG. 6 is a schematic diagram of an embodiment of an electrical device in which a secondary battery is used as a power source of the present application.
  • the first aspect of the present application provides a ternary precursor material, including an inner core and an outer shell, wherein (1) the molecular formula of the inner core is Ni x Co y Mn 1-xy (OH) 2 ⁇ a , where: 0.8 ⁇ x ⁇ 1.0, 0 ⁇ y ⁇ 0.2, 0 ⁇ a ⁇ 0.2; the shell contains doping elements; (2) the deformation stacking fault rate f D of the ternary precursor material is ⁇ 4%.
  • the test and calculation method of the crystal deformation stacking fault rate f D is as follows: First, use the Bruker D8 Discovery equipment to test the X-ray diffraction pattern of the ternary precursor material. Scan at a high speed, preferably at a scanning speed of 0.5°/min, to obtain an X-ray diffraction spectrum. Secondly, the above-mentioned X-ray diffraction spectrum is fitted, and the relevant parameters of (001), (101), (102) diffraction peaks obtained are brought into the following expressions:
  • B (101) is the half-width of the precursor (101) diffraction peak
  • B (102) is the half-width of the precursor (102) diffraction peak
  • D (001) is the crystal of the precursor (001) diffraction peak Particle size
  • the ternary precursor material described in this application can greatly stabilize the coordination atoms in the center of the tetrahedron, suppress the formation of vacancies, and ensure the stability of the actual stoichiometric ratio and transition metal valence , promote the order and structural stability of high-nickel ternary cathode materials, and improve cycle performance; at the same time, the high nickel content in the core in the core-shell structure design of the precursor is very conducive to the gram capacity of the cathode material after sintering, and the enrichment in the shell After sintering, the doping elements can not only protect the surface of the active material from the corrosion of the side reaction products of the electrolyte to improve the high-temperature cycle performance, but also serve as an excellent Li + conductor to improve the kinetic performance.
  • the fragmentation rate of the particles of the ternary precursor material under a pressure of 1 ton is ⁇ 50%; optionally ⁇ 25%.
  • the fragmentation rate of the particles of the ternary precursor material under the pressure of 1 ton is ⁇ 24%, ⁇ 23%, ⁇ 22% or ⁇ 21%.
  • the physical definition of D v1 is the corresponding particle size when the cumulative volume distribution percentage of the material reaches 1%.
  • the fragmentation rate of the particles of the material after compression is further limited, so that the obtained ternary precursor material has high mechanical strength, which is beneficial to suppress the high mechanical strength after sintering.
  • the cracking of nickel ternary cathode material under high temperature cycle improves cycle performance.
  • the doping element is selected from one or more of tungsten, antimony, tantalum, molybdenum, yttrium and magnesium; and/or the mass fraction of the doping element is 1000-8000ppm, Optionally, 2000-6000ppm; and/or, the doping element is tungsten element, preferably doped in the form of tungsten oxide.
  • the mass fraction of the doping element can be understood as the mass fraction of the doping element accounting for all elements within the range of 10 to 100 nm of the outer shell, which can be determined by SEM (Scanning Electron Microscope, scanning electron microscope) -EDX (Energy Dispersive X-Ray Spectroscopy, energy dispersive X-ray spectrometer)) combined detection: first select the range of the shell to be observed in the SEM, then switch the probe to EDX mode, and perform single-point or surface scanning on the selected area, Then check the possible elements for component analysis or other similar methods.
  • SEM Sccanning Electron Microscope, scanning electron microscope
  • EDX Electronic X-Ray Spectroscopy, energy dispersive X-ray spectrometer
  • the doping element of the shell and the mass fraction of the doping element are further defined, and the doping of the element in the shell can suppress the 101 crystal plane of the ternary precursor material
  • the growth can promote the growth of the 001 crystal plane of the ternary precursor material under high temperature sintering, which is helpful to improve the gram capacity of the positive electrode material after sintering.
  • the diameter of the inner core is 2 ⁇ m ⁇ 9 ⁇ m; and/or, the thickness of the outer shell is 0.5 ⁇ m ⁇ 4 ⁇ m.
  • Thickness test put the argon-polished sample into the SEM and select the reference mode to observe the inner core and outer shell of the sample.
  • ternary precursor material described in this application its core diameter and shell thickness are further defined, which is helpful for sintering a high-nickel ternary cathode material with high gram capacity and compatibility with the compressive strength of powder.
  • the particle size D v 50 of the ternary precursor material is 3 ⁇ m to 17 ⁇ m, preferably 6 ⁇ m to 10 ⁇ m; and/or the particle size SPAN value of the ternary precursor material is ⁇ 0.65, preferably is ⁇ 0.45.
  • the average particle size D v 50 can be measured with reference to the standard GB/T 19077.1-2016 using a laser particle size analyzer (such as Malvern Master Size 3000).
  • the physical definition of D v 10 is the particle size corresponding to the cumulative volume distribution percentage of the material reaching 10%
  • the physical definition of D v 50 is the particle size corresponding to the cumulative volume distribution percentage of the material reaching 50%
  • D v 90 The physical definition is the particle size corresponding to the cumulative volume distribution percentage of the material reaching 90%.
  • the particle size SPAN is (D v 90-D v 50)/D v 10.
  • the ternary precursor material described in this application its particle size is also limited, which is conducive to sintering a high-nickel ternary positive electrode material with high compaction density, and is beneficial to the gram capacity of the positive electrode material after sintering. Furthermore, its particle size distribution is also limited, which is beneficial to improve the uniformity of lithium mixed in the high-nickel ternary cathode material after sintering, and can ensure the uniformity of physical and chemical properties; at the same time, there are almost no fine particles and micropowders, which can help Inhibits gas production and particle fragmentation at high temperatures.
  • the BET of the ternary precursor material is 4m 2 /g-16m 2 /g, preferably 8m 2 /g-12m 2 /g.
  • the specific surface area of material is meaning known in the art, can be measured with instrument and method known in the art, for example can be tested with nitrogen adsorption specific surface area analysis test method, and calculate with BET (Brunauer Emmett Teller) method, wherein nitrogen adsorption
  • BET Brunauer Emmett Teller
  • the specific surface area analysis test can be carried out through the NOVA 2000e specific surface area and pore size analyzer of the American Quanta Company.
  • the test method is as follows: Take 8.000g ⁇ 15.000g of material with an empty sample tube after weighing, stir the material evenly and weigh it, put the sample tube into the NOVA 2000e degassing station for degassing, and weigh the degassed The total mass of the degassed material and the sample tube is calculated by subtracting the mass of the empty sample tube from the total mass to obtain the mass G of the degassed material. Put the sample tube into NOVA 2000e, measure the adsorption amount of nitrogen on the surface of the material under different relative pressures, obtain the adsorption amount of the monomolecular layer based on the Brownauer-Etter-Taylor multilayer adsorption theory and its formula, and then calculate the total amount of the material.
  • the surface area A is the specific surface area of the material calculated by A/G.
  • the BET of the ternary precursor material is further defined, which is helpful for sintering a high-nickel ternary cathode material with high gram capacity and surface chemical stability.
  • the intensity ratio of the 001 crystal plane diffraction peak to the 101 crystal plane diffraction peak of the ternary precursor material is 0.6-1.2, preferably 0.9-1.1.
  • the X-ray diffraction spectrum can be obtained by X-ray powder diffractometer (X'pert PRO) according to the general rules of X-ray diffraction analysis method JIS K 0131-1996 , and then the ternary The ratio E of the intensity of the 001 crystal plane diffraction peak to the 101 crystal plane diffraction peak of the precursor material, wherein, I (001) is the peak area of the 001 crystal plane diffraction peak, and I (101) is the peak area of the 101 crystal plane diffraction peak.
  • the 2 ⁇ angle corresponding to the 001 crystal plane is 17.8°-22.8°; the 2 ⁇ angle corresponding to the 101 crystal plane is 36.8°-42.0°.
  • the ratio of the intensity ratio of the 001 crystal plane diffraction peak to the 101 crystal plane diffraction peak of the ternary precursor material is further defined, which helps to sinter a high isotropy Nickel ternary cathode material.
  • the primary particle aspect ratio of the ternary precursor material is 2-8.
  • the primary particle is a single grain in the aggregate, which is usually rectangular in the scanning electron microscope picture, and the ratio of its length to width is measured as the aspect ratio. According to this method, 30 particles are taken at any position of the sample for Take the average value after measurement.
  • the aspect ratio of the doping elements of the ternary precursor material is further defined, so that the uniform doping in the outer shell is beneficial to enhance the stability of the surface structure and the stacking order of the sheets Doping elements can improve the cycle performance of the sintered high-nickel ternary cathode material.
  • the length of a particle or particle refers to the largest dimension of the particle or particle.
  • the morphology of the primary particles can be measured using instruments and methods known in the art, such as a scanning electron microscope (eg, Hitachi S-4800, Japan).
  • any one of the above-mentioned ternary precursor materials can be prepared.
  • the method of the present application has two steps of nucleation and nuclear growth in the S2 step, and can synthesize a radially distributed shell structure on the nucleus; and the application finds that, By limiting the working concentration of ammonia water to 0.6-1mol/L, preferably 0.65-0.75mol/L, and keeping the working concentration of ammonia water constant during the synthesis process, the deformation stacking fault rate of the obtained ternary precursor material can be Both f D and the fragmentation rate after compression are significantly reduced, which can meet the requirements of this application.
  • the method of the present application comprises the following steps:
  • S1 Provide mixed salt solution, lye, ammonia water, salt solution of doping elements and base liquid, wherein the mixed salt solution contains soluble nickel salt, cobalt salt and manganese salt;
  • the pH is maintained at 9.5-10.5 and the working concentration of ammonia water is 6.5-1 mol/L.
  • the soluble nickel salt is selected from one or more of nickel sulfate, nickel nitrate, and nickel acetate.
  • the soluble cobalt salt is selected from one or more of cobalt sulfate, cobalt oxalate, cobalt nitrate and cobalt acetate.
  • the soluble manganese salt is selected from one or more of manganese sulfate, manganese nitrate and manganese acetate.
  • the salt solution doped with elements may be doped with nitrate solutions, carbonate solutions, etc., for example, tungsten salts are selected from one or more of sodium tungstate and ammonium tungstate.
  • step S2 pure water is added to the reaction kettle as the bottom liquid, ammonia water and lye are added to adjust the pH in the bottom liquid to 9.5-10.5, and the concentration of ammonia water is 0.5-1mol/L, preferably 0.65 ⁇ 0.75mol/L, start stirring, control the reaction temperature at 65 ⁇ 85°C, pump the nickel-cobalt-manganese mixed salt solution, lye, and ammonia water into the reaction kettle according to a certain flow rate, keep the pH and ammonia concentration unchanged, Protected by an inert gas during the reaction, a high-nickel ternary precursor core slurry with a narrow volume distribution and stable average particle diameter Dv50 is intermittently synthesized to obtain the ternary precursor core slurry.
  • step S2 lye and ammonia water are added to the bottom liquid before the reaction, so that the pH of the bottom liquid is 9.5-10.5, and the concentration of ammonia water is 0.5-1mol/L, preferably 0.65-0.75 mol/L; and/or maintain the working concentration of the ammonia water at 0.65-0.75 mol/L; and/or keep the reaction temperature at 65-85° C.; and/or the stirring rate at 150-350 rpm.
  • step S3 the salt solution, lye, and ammonia water of doping elements are combined and pumped into the reactor according to a certain flow rate, and the pH is maintained at 9.5-10.5, and the concentration of ammonia water is 0.5-1mol/L , preferably 0.65-0.75 mol/L, and intermittently synthesize a high-nickel ternary precursor slurry with a narrow volume distribution and a stable average particle size D v50 of the core-shell structure.
  • step S3 the working concentration of the ammonia water is maintained at 0.65-0.75 mol/L; and/or the reaction temperature is 65-85° C.; and/or the stirring rate is 150-350 rpm.
  • the method of this application includes two steps of nucleation and nucleation growth, can synthesize a radially distributed shell structure on the nucleus, and can obviously improve the cycle performance of the high-nickel ternary positive electrode material after sintering. Moreover, the applied method limits the working concentration of ammonia water and changes the feeding method, which can ensure the stable synthesis of high-nickel ternary precursors and avoid process changes caused by system fluctuations due to excessive concentration.
  • the embodiment of the present application also provides a positive electrode active material, which is composed of the above-mentioned ternary precursor material and lithium composite.
  • the above-mentioned ternary precursor material and lithium salt are mixed and sintered to obtain a positive electrode active material.
  • the ternary precursor material and lithium salt can be mixed in a coulter mixer, high mixer or inclined trial mixer. Put the mixed material into the atmosphere sintering furnace for sintering.
  • the sintering atmosphere is an air atmosphere or an oxygen atmosphere; the sintering temperature is 700-900° C., and the sintering time is 10-20 hours.
  • the lithium salt can be lithium oxide (Li 2 O), lithium phosphate (Li 3 PO 4 ), lithium dihydrogen phosphate (LiH 2 PO 4 ), lithium acetate (CH 3 COOLi), lithium hydroxide (LiOH), lithium carbonate ( One or more of Li 2 CO 3 ) and lithium nitrate (LiNO 3 ), but not limited thereto.
  • the Li/Me molar ratio of the positive electrode active material is 0.9 ⁇ 1.1, and Me is nickel, cobalt, or manganese.
  • the sintered product can also be crushed and sieved to obtain a positive electrode active material with optimized particle size distribution and specific surface area.
  • the crushing method which can be selected according to actual needs, such as using a particle crusher.
  • the positive electrode active material obtained according to the method of the present application has a core-shell structure, in which the pores of the inner core are uniform and the particles are radially distributed, and the doping elements of the outer shell are uniformly distributed, which can not only provide a higher gram capacity, but also protect the surface of the active material. Corroded by the side reaction products of the electrolyte, the high-temperature cycle life is improved, and it can also be used as an excellent Li + conductor to improve the kinetic performance and suppress the growth of impedance.
  • the second aspect of the embodiment of the present application provides a positive electrode sheet, and the positive electrode sheet adopts the positive electrode active material according to the first aspect of the embodiment of the present application.
  • the positive electrode sheet of the embodiment of the present application can make the secondary battery have both high gram capacity and cycle performance.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.
  • the positive electrode current collector includes two opposite surfaces in its thickness direction, and the positive electrode active material layer is stacked on any one or both of the two surfaces of the positive electrode current collector.
  • the positive active material layer includes the positive active material according to the first aspect of the embodiment of the present application.
  • a conductive agent and a binder may also be included in the positive electrode active material layer.
  • the present application does not specifically limit the types of the conductive agent and the binder in the positive electrode active material layer, which can be selected according to actual needs.
  • the conductive agent can be one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers;
  • the binder can be styrene-butadiene Rubber (SBR), water-based acrylic resin (water-based acrylic resin), carboxymethyl cellulose (CMC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB ), ethylene-vinyl acetate copolymer (EVA), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene
  • SBR styrene-butadiene Rubber
  • VDF polyvinylidene fluor
  • the positive current collector can be metal foil or porous metal plate with good electrical conductivity and mechanical properties, and its material can be one or more of aluminum, copper, nickel, titanium, silver and their respective alloys.
  • the positive electrode current collector is, for example, aluminum foil.
  • the positive electrode sheet can be prepared according to conventional methods in the art.
  • the positive electrode active material, conductive agent and binder are dispersed in a solvent
  • the solvent can be N-methylpyrrolidone (NMP) or deionized water to form a uniform positive electrode slurry
  • the positive electrode slurry is coated on the positive electrode current collector After drying, rolling and other processes, the positive electrode sheet is obtained.
  • NMP N-methylpyrrolidone
  • the third aspect of the embodiment of the present application provides a lithium-ion secondary battery.
  • the lithium-ion battery includes a positive pole piece, a negative pole piece, a separator and an electrolyte, wherein the positive pole piece is the positive pole piece according to the second aspect of the embodiment of the present application.
  • the lithium ion secondary battery takes into account both high gram capacity and cycle performance.
  • the above-mentioned negative electrode sheet may be a metal lithium sheet.
  • the above-mentioned negative electrode sheet may also include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.
  • the negative electrode current collector includes two opposite surfaces in its thickness direction, and the negative electrode active material layer is stacked on any one or both of the two surfaces of the negative electrode current collector.
  • the negative active material layer includes a negative active material.
  • the embodiment of the present application does not specifically limit the type of negative electrode active material, which can be selected according to actual needs.
  • the negative active material layer may further include a conductive agent and a binder.
  • the embodiment of the present application does not specifically limit the types of the conductive agent and the binder in the negative electrode active material layer, which can be selected according to actual needs.
  • the conductive agent is one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers
  • the binder is styrene-butadiene rubber (SBR), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), water-based acrylic resin (water-based acrylic resin) and carboxymethyl cellulose (CMC) one or more of.
  • the negative active material layer may also optionally include a thickener such as carboxymethylcellulose (CMC).
  • CMC carboxymethylcellulose
  • the negative current collector can be metal foil or porous metal plate with good electrical conductivity and mechanical properties, and its material can be one or more of copper, nickel, titanium, iron and their respective alloys.
  • the negative electrode current collector is, for example, copper foil.
  • the negative electrode sheet can be prepared according to conventional methods in the art. For example, disperse the negative electrode active material, conductive agent, binder and thickener in a solvent, the solvent can be N-methylpyrrolidone (NMP) or deionized water to form a uniform negative electrode slurry, and coat the negative electrode slurry On the negative electrode current collector, after drying, rolling and other processes, the negative electrode sheet is obtained.
  • NMP N-methylpyrrolidone
  • the electrolyte may be a solid electrolyte, such as a polymer electrolyte, an inorganic solid electrolyte, etc., but is not limited thereto.
  • An electrolytic solution may also be used as the electrolyte.
  • a solvent and a lithium salt dissolved in the solvent are included.
  • the solvent can be a non-aqueous organic solvent, such as ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), carbonic acid Dipropyl acetate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA) , one or more of methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB) and ethyl butyrate (EB), preferably Two or more.
  • EC ethylene carbonate
  • PC propylene carbonate
  • EMC diethyl carbonate
  • DMC dimethyl carbonate
  • DPC carbonic acid Dipropyl acetate
  • MPC methyl propyl
  • the lithium salt can be LiPF 6 (lithium hexafluorophosphate), LiBF 4 (lithium tetrafluoroborate), LiClO 4 (lithium perchlorate), LiAsF 6 (lithium hexafluoroarsenate), LiFSI (lithium bisfluorosulfonimide), LiTFSI (lithium bistrifluoromethanesulfonyl imide), LiTFS (lithium trifluoromethanesulfonate), LiDFOB (lithium difluorooxalate borate), LiBOB (lithium bisoxalate borate), LiPO 2 F 2 (lithium difluorophosphate), One or more of LiDFOP (lithium difluorooxalate phosphate) and LiTFOP (lithium tetrafluorooxalate phosphate), such as LiPF 6 (lithium hexafluorophosphate), LiBF 4 (lithium tetrafluoroborate), LiBOB (lithium
  • the electrolyte also optionally contains other additives, such as vinylene carbonate (VC), ethylene carbonate (VEC), fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), trifluoroform ethylene carbonate (TFPC), succinonitrile (SN), adiponitrile (ADN), glutaronitrile (GLN), hexanetrinitrile (HTN), 1,3-propane sultone (1,3- PS), ethylene sulfate (DTD), methylene methyl disulfonate (MMDS), 1-propene-1,3-sultone (PST), 4-methylethylene sulfate (PCS), 4-ethyl ethylene sulfate (PES), 4-propyl ethylene sulfate (PEGLST), propylene sulfate (TS), 1,4-butane sultone (1,4-BS), sulfurous acid Ethylene ester (DTO), dimethyl sulfite (DM
  • the lithium ion secondary battery of the embodiment of the present application has no special limitation on the separator, and any known porous structure separator with electrochemical stability and mechanical stability can be selected, such as glass fiber, non-woven fabric, polyethylene (PE ), polypropylene (PP) and polyvinylidene fluoride (PVDF) one or more single-layer or multi-layer films.
  • any known porous structure separator with electrochemical stability and mechanical stability can be selected, such as glass fiber, non-woven fabric, polyethylene (PE ), polypropylene (PP) and polyvinylidene fluoride (PVDF) one or more single-layer or multi-layer films.
  • the positive pole piece and the negative pole piece are stacked alternately, and an isolation film is set between the positive pole piece and the negative pole piece to play the role of isolation to obtain a battery cell, or the battery core can be obtained after winding. Place the cell in the casing, inject the electrolyte, and seal it to obtain a lithium-ion secondary battery.
  • the positive pole piece, the negative pole piece and the separator can be made into an electrode assembly through a winding process or a lamination process.
  • the secondary battery may include an outer package.
  • the outer package can be used to package the above-mentioned electrode assembly and electrolyte.
  • the outer packaging of the secondary battery may be a hard case, such as a hard plastic case, aluminum case, steel case, and the like.
  • the outer packaging of the secondary battery may also be a soft bag, such as a bag-type soft bag.
  • the material of the soft bag can be plastic, such as one or more of polypropylene (PP), polybutylene terephthalate (PBT), polybutylene succinate (PBS) and the like.
  • FIG. 1 shows a secondary battery 5 with a square structure as an example.
  • the outer package may include a housing 51 and a cover 53 .
  • the housing 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plates enclose to form an accommodating cavity.
  • the housing 51 has an opening communicating with the receiving chamber, and the cover plate 53 is used to cover the opening to close the receiving chamber.
  • the positive pole piece, the negative pole piece and the separator can be formed into an electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is packaged in the accommodating cavity. Electrolyte is infiltrated in the electrode assembly 52 .
  • the number of electrode assemblies 52 contained in the secondary battery 5 can be one or several, and can be adjusted according to requirements.
  • the secondary battery can be assembled into a battery module, and the number of secondary batteries contained in the battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module.
  • FIG. 3 is a battery module 4 as an example.
  • a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4 .
  • the plurality of secondary batteries 5 may be fixed by fasteners.
  • the battery module 4 may also include a case having a housing space in which a plurality of secondary batteries 5 are accommodated.
  • the above-mentioned battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
  • the battery box includes an upper box body 2 and a lower box body 3 , the upper box body 2 is used to cover the lower box body 3 and forms a closed space for accommodating the battery module 4 .
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • Embodiments of the present application further provide an electric device, the electric device includes at least one of the secondary battery, the battery module, and the battery pack of the present application.
  • the secondary battery, battery module or battery pack can be used as a power source of the electric device, and can also be used as an energy storage unit of the electric device.
  • the electric device can be, but not limited to, mobile devices (such as mobile phones, notebook computers, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.
  • the electric device can select a secondary battery, a battery module or a battery pack according to its usage requirements.
  • FIG. 6 is an example of an electrical device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • a battery pack or a battery module can be used.
  • the electric device may be a mobile phone, a tablet computer, a notebook computer, and the like.
  • the electrical device is usually required to be light and thin, and a secondary battery can be used as a power source.
  • the doping element is tungsten, and the doping concentration of the tungsten element in the shell is 6000ppm.
  • Preparation methods include:
  • the positive pole piece, the separator and the metal lithium sheet are stacked in sequence, and the above-mentioned electrolyte solution is injected to assemble the button battery.
  • the positive electrode active material prepared above Disperse the positive electrode active material prepared above, the conductive agent acetylene black and the binder PVDF into the solvent NMP according to the weight ratio of 94:3:3 and mix them uniformly to obtain the positive electrode slurry; apply the positive electrode slurry evenly on the positive electrode current collector On the aluminum foil, after drying and cold pressing, the positive electrode sheet is obtained.
  • Negative electrode active material artificial graphite, hard carbon, conductive agent acetylene black, binder styrene-butadiene rubber (SBR), thickener carbon methylcellulose sodium (CMC) are dispersed according to the weight ratio 90:5:2:2:1 and mixed evenly in deionized water to obtain negative electrode slurry; uniformly coating the negative electrode slurry on the aluminum foil of the negative electrode current collector, drying and cold pressing to obtain the negative electrode sheet.
  • PE Polyethylene
  • Example 1 The difference from Example 1 is that the relevant parameters in the preparation steps of the ternary precursor material are changed, and the content of doping elements is adjusted.
  • the deformation stacking fault rate and fragmentation rate of the obtained ternary precursor material were tested, and the core diameter, shell thickness, Dv50, particle size SPAN value, disposable particle aspect ratio, BET and other parameters, see Table 1 and Table 2 for details; wherein Table 1 is the relevant parameters in the preparation steps of the ternary precursor material, and Table 2 is the relevant parameters of the obtained ternary precursor material.
  • Example 10 involving multi-element doping
  • the content of each doping element is basically the same, see Table 1 for details.
  • the deformation stacking fault rate and fragmentation rate of the obtained ternary precursor material were tested, and the core diameter, shell thickness, Dv50, particle size SPAN value, disposable particle aspect ratio, BET and other parameters, see Table 1 and Table 2 for details; wherein Table 1 is the relevant parameters in the preparation steps of the ternary precursor material, and Table 2 is the relevant parameters of the obtained ternary precursor material.
  • Example 1 The difference from Example 1 is that the relevant parameters in the preparation steps of the ternary precursor material are changed, and the content of doping elements is adjusted.
  • the deformation stacking fault rate and fragmentation rate of the obtained ternary precursor material were tested, and the core diameter, shell thickness, Dv50, particle size SPAN value, disposable particle aspect ratio, BET and other parameters, see Table 1 and Table 2 for details; wherein Table 1 is the relevant parameters in the preparation steps of the ternary precursor material, and Table 2 is the relevant parameters of the obtained ternary precursor material.
  • Example 1 The difference from Example 1 is that changing the relevant parameters in the preparation steps of the positive electrode active material makes the deformation stacking fault rate or fragmentation rate of the material change; the deformation stacking fault rate and fragmentation rate of the obtained ternary precursor material are tested. Crack rate, and measured the core diameter, shell thickness, Dv50, particle size SPAN value, disposable particle aspect ratio, BET and other parameters of the ternary precursor material, see Table 1 and Table 2 for details; Table 1 is For the relevant parameters in the preparation steps of the ternary precursor material, Table 2 shows the relevant parameters of the obtained ternary precursor material.
  • the deformation stacking fault rate and fragmentation rate of the obtained ternary precursor material were tested, and the core diameter, shell thickness, Dv50, particle size SPAN value, disposable particle aspect ratio, BET and other parameters, see Table 1 and Table 2 for details; wherein Table 1 is the relevant parameters in the preparation steps of the ternary precursor material, and Table 2 is the relevant parameters of the obtained ternary precursor material.
  • Deformation stacking fault rate f D Use Bruker D8 Discovery equipment to test the X-ray diffraction pattern of the ternary precursor material, scan slowly within the range of 2 ⁇ angle of 10° to 70°, and the scanning speed is preferably 0.5°/min. Obtain an X-ray diffraction pattern. Secondly, the above-mentioned X-ray diffraction spectrum is fitted, and the relevant parameters of (001), (101), (102) diffraction peaks obtained are brought into the following expressions:
  • B (101) is the half-width of the precursor (101) diffraction peak
  • B (102) is the half-width of the precursor (102) diffraction peak
  • D (001) is the crystal of the precursor (001) diffraction peak Particle size, and then calculate the corresponding value.
  • the physical definition of D v1 is the corresponding particle size when the cumulative volume distribution percentage of the material reaches 1%.
  • Full battery capacity charge the full battery at room temperature with 1/3C constant current to 4.25V, and discharge it with 1/3C constant current to 2.8V, and the result is 1/3C gram capacity.
  • Full battery first effect In the full battery capacity test, the ratio of the discharge capacity to the charge capacity is the first Coulombic efficiency, that is, the full battery first effect.
  • Full battery 45°C cycle test The full battery is subjected to a 1C constant current continuous charge and discharge test in a high and low temperature box at 45°C, and the capacity is recorded at 30 cycles, and the ratio of the capacity to the first cycle is the 30cls capacity retention rate; Record the DC internal resistance (DCR) value in the high SOC state at 30 laps, and subtract 1 from the DCR ratio of the first lap to get the 30cls DCR growth rate.
  • DCR DC internal resistance
  • each parameter in the ternary precursor material satisfies a predetermined relationship, which can further ensure that the positive electrode active material has high structural stability;
  • the crack rate makes the obtained ternary precursor material have high mechanical strength, which is beneficial to suppress the cracking of the high-nickel ternary cathode material after sintering under high temperature cycle, and further improves the cycle performance.
  • Comparative examples 1-8 cannot meet various reaction conditions in the preparation process, so that the deformation stacking fault rate of the ternary precursor material is high, which is not conducive to the gram capacity of the positive electrode material after sintering, and is also not conducive to improving the cycle of the battery. performance.

Abstract

本申请实施例提供一种三元前驱体材料、其制备方法及正极活性物质。本申请提供了一种三元前驱体材料，包括内核与外壳，其中(1)所述内核分子式为Ni xCo yMn 1-x-y(OH) 2±a，其中：0.8≤x＜1.0，0＜y＜0.2，0＜a＜0.2；所述外壳包含掺杂元素；(2)所述三元前驱体材料的形变层错率f D≤4％。使用所述前驱体材料烧结成的正极活性物质，使得二次电池能兼顾较高的克容量和循环性能。

Description

三元前驱体材料及其制备方法和应用 技术领域
本申请涉及二次电池技术领域，尤其涉及一种三元前驱体材料及其制备方法和应用。
背景技术
近年来，二次电池的应用范围越来越广泛，例如，二次电池广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。二次电池的广泛应用，导致当前对电池的综合性能要求也越来越高，越来越多的应用场景要求动力电池既具备较高的克容量，又具有良好的充放电特性。
正极活性物质对二次电池能量密度的提升具有重要影响。其中高镍三元正极活性物质具有较高的克容量，因而有望成为二次电池的下一代主流正极活性物质。但是，高镍正极活性材料随着镍含量的不断提高，其结构稳定性越来越差，进而影响二次电池的性能。
发明内容
本申请的目的在于针对现有技术的不足，提供一种三元前驱体材料。本申请还提供了所述三元前驱体材料的制备方法和使用该三元前驱体材料的正极活性物质、二次电池、电池模块、电池包。本申请提供的三元前驱体材料，创造性的引入层错率与碎裂强度作为参数指标进行合成的指引，使用所述前驱体材料烧结成的正极活性物质能兼顾较高的克容量发挥和循环性能。
为了达到上述目的，本申请的第一方面提供了一种三元前驱体材料，包括内核与外壳，其中(1)所述内核分子式为Ni xCo yMn 1-x-y(OH) 2± a，其中：0.8≤x＜1.0，0＜y＜0.2，0＜a＜0.2；所述外壳包含掺杂元素；(2)所述三元前驱体材料的形变层错率f D≤4％。
根据本申请所述的三元前驱体材料，其中形变层错率f D≤4％，可以极大地稳定四面体中心的配位原子，抑制空位的形成，保证实际化学计量比与过渡金属化合价的稳定，促进高镍三元正极材料的有序度与结构稳定性，提升循环性能；同时前驱体核壳结构设计中内核的高镍含量非常 有利于烧结后正极材料的克容量发挥，外壳中富集的掺杂元素在烧结后不仅可以保护活性材料表面受到电解液副反应产物的腐蚀提高高温循环性能，还能作为优良的Li +导体提升动力学性能。在任选的实施方案中，三元前驱体材料的颗粒在1吨压力下的碎裂率≤50％；可选≤25％。
根据本申请所述的三元前驱体材料，进一步限定了所述材料的颗粒抗压后的碎裂率，使获得的三元前驱体材料具有很高的机械强度，有利于抑制烧结后的高镍三元正极材料在高温循环下的开裂，提升循环性能。
在任选的实施方案中，所述掺杂元素选自钨、锑、钽、钼、钇和镁元素的一种或多种；和/或所述掺杂元素的质量分数为1000～8000ppm，可选2000～6000ppm；和/或，所述掺杂元素为钨元素，优选以钨的氧化物的形式掺杂。
根据本申请所述的三元前驱体材料，进一步限定了所述外壳的掺杂元素和所述掺杂元素的质量分数，所述元素在外壳的掺杂可以抑制三元前驱体材料101晶面的生长从而在高温烧结下促进三元前驱体材料001晶面的生长，有助于提高烧结后正极材料的克容量发挥。
在任选的实施方案中，所述内核直径为2μm～9μm；和/或，所述外壳厚度为0.5μm～4μm。
根据本申请所述的三元前驱体材料，进一步限定了其内核直径和外壳厚度，有助于烧结出高克容量发挥与粉体抗压强度兼容的高镍三元正极材料。
在任选的实施方案中，所述三元前驱体材料的粒径Dv50为3μm～17μm，优选为6μm～10μm；和/或所述三元前驱体材料的粒度SPAN值≤0.65，优选为≤0.45。
根据本申请所述的三元前驱体材料，还限定了其粒径，有助于烧结出高压实密度的高镍三元正极材料，并且有利于烧结后正极材料的克容量发挥。进一步地，还限定了其粒度分布，有利于提高烧结后的高镍三元正极材料的混锂均匀性，能够保证物理化学性质的均一；同时几乎没有细小颗粒与微粉的存在，可以有助于抑制高温下产气与颗粒碎裂。
在任选的实施方案中，所述三元前驱体材料的BET为4m 2/g～16m 2/g，优选为8m 2/g～12m 2/g。
根据本申请所述的三元前驱体材料，进一步限定了三元前驱体材料的BET，有助于烧结出高克容量发挥与表面化学稳定性的高镍三元正极材料。
在任选的实施方案中，所述三元前驱体材料的001晶面衍射峰与101晶面衍射峰的强度之比为0.6～1.2，优选为0.9～1.1。
根据本申请所述的三元前驱体材料，进一步限定了三元前驱体材料的001晶面衍射峰与101晶面衍射峰的强度之比，有助于烧结出具有较 高的各向同性的高镍三元正极材料。
在任选的实施方案中，三元前驱体材料的一次粒子长宽比为2～8。
根据本申请所述的三元前驱体材料，进一步限定了三元前驱体材料掺杂元素的长宽比，使得在外壳中均匀掺杂有利于增强表面结构稳定性与片层堆叠有序性的掺杂元素，对烧结后的高镍三元正极材料循环性能有改善效果。
本申请的第二方面提供了一种三元前驱体材料的制备方法，其中，所述方法包括以下步骤：
S1：提供混合盐溶液、碱液、氨水、掺杂元素的盐溶液，其中所述混合盐溶液包含可溶性镍盐、钴盐与锰盐；
S2：在反应釜中加入纯水作为底液，控制反应温度，搅拌并将混合盐溶液、碱液和氨水合流泵入反应釜中，得到所述三元前驱体内核浆液；其中，维持pH以及氨水的工作浓度不变；
S3：将掺杂元素的盐溶液、碱液和氨水合流泵入反应釜中，合成所述三元前驱体浆液，烘干并烧结，得到所述三元前驱体材料；其中，维持pH以及氨水的工作浓度不变。
其中，所述三元前驱体材料包括内核与外壳，所述内核分子式为Ni xCo yMn 1-x-y(OH) 2±a，其中：0.8≤x＜1.0，0＜y＜0.2，0＜a＜0.2；所述外壳包含掺杂元素；所述三元前驱体材料的形变层错率f D≤4％。
在任选的实施方案中，S2中，pH为9.5～10.5，所述氨水的工作浓度为0.6～1mol/L，可选0.65～0.75mol/L；和/或
使反应温度为65～85℃；和/或搅拌速率为150～350rpm。
在任选的实施方案中，S3中，pH为9.5～10.5，所述氨水的工作浓度为0.65～0.75mol/L。
采用本申请的制备方法，可以得到优良的核壳结构高镍三元正极材料，并可以控制核壳中成分的差异性与含量，达到所需的高容量与高结构稳定性的目的。此外，本申请的方法在S2步骤有成核与核生长两个步骤，能在核上合成出径向分布的外壳结构，能明显改善烧结后的高镍三元正极材料的循环性能。进一步地，通过控制本申请的S2步骤中氨水的工作浓度，有效降低了三元前驱体材料的形变层错率和碎裂度。
本申请的第三方面提供了一种正极活性物质，包含所述的三元前驱体材料；或由所述的方法制备获得的三元前驱体材料。
在任选的实施方案中，Li/Me摩尔比为0.9～1.1，Me为镍、钴、锰。
本申请的第四方面提供了一种二次电池，包括所述正极活性物质。
本申请的第五方面提供了一种电池模块，包括所述的二次电池。
本申请的第六方面提供了一种电池包，包括所述的二次电池或所述的电池模块。
本申请的第七方面提供了一种用电装置，包括所述的二次电池、根所述的电池模块、所述的电池包中的至少一种。
本申请的电池模块、电池包和用电装置包括本申请提供的二次电池，因而至少具有与所述二次电池相同的优势。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据附图获得其他的附图。
图1是本申请的二次电池的一实施方式的示意图。
图2是本申请的二次电池的一实施方式的分解示意图。
图3是本申请的电池模块的一实施方式的示意图。
图4是本申请的电池包的一实施方式的示意图。
图5是图4的分解图。
图6是本申请的二次电池用作电源的用电装置的一实施方式的示意图。
具体实施方式
下面结合附图和实施例对本申请的实施方式作进一步详细描述。以下实施例的详细描述和附图用于示例性地说明本申请的原理，但不能用来限制本申请的范围，即本申请不限于所描述的实施例。
在本申请的描述中，需要说明的是，除非另有说明，“多个”的含义是两个以上；术语“上”、“下”、“左”、“右”、“内”、“外”等指示的方位或位置关系仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。此外，术语“第一”、“第二”、“第三”等仅用于描述目的，而不能理解为指示或暗示相对重要性。“垂直”并不是严格意义上的垂直，而是在误差允许范围之内。“平行”并不是严格意义上的平行，而是在误差允许范围之内。
下述描述中出现的方位词均为图中示出的方向，并不是对本申请的具体结构进行限定。在本申请的描述中，还需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”应做广义理解，例 如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连，也可以通过中间媒介间接相连。对于本领域的普通技术人员而言，可视具体情况理解上述术语在本申请中的具体含义。
三元前驱体材料和正极活性物质
本申请的第一方面提供了一种三元前驱体材料，包括内核与外壳，其中(1)所述内核分子式为Ni xCo yMn 1-x-y(OH) 2±a，其中：0.8≤x＜1.0，0＜y＜0.2，0＜a＜0.2；所述外壳包含掺杂元素；(2)所述三元前驱体材料的形变层错率f D≤4％。
其中，晶体形变层错率f D的测试与计算方法如下：首先，采用Bruker D8 Discovery设备，对三元前驱体材料进行X射线衍射图谱测试，在2θ角度为10°～70°的范围内慢速扫描，扫描速度优选0.5°/min，获得X射线衍射图谱。其次，将上述X射线衍射谱图拟合，得到的(001)、(101)、(102)衍射峰相关参数带入至以下表达式：
Figure PCTCN2021141873-appb-000001
其中，B (101)是前驱体(101)衍射峰的半峰宽，B (102)是前驱体(102)衍射峰的半峰宽，D (001)是前驱体(001)衍射峰的晶粒度，随后计算便可得到相应数值。详见《绿色二次电池的材料表征和电极过程机理》，该处通过引用将相关内容并入本文。
根据本申请所述的三元前驱体材料其形变层错率f D≤4％，可以极大地稳定四面体中心的配位原子，抑制空位的形成，保证实际化学计量比与过渡金属化合价的稳定，促进高镍三元正极材料的有序度与结构稳定性，提升循环性能；同时前驱体核壳结构设计中内核的高镍含量非常有利于烧结后正极材料的克容量发挥，外壳中富集的掺杂元素在烧结后不仅可以保护活性材料表面受到电解液副反应产物的腐蚀提高高温循环性能，还能作为优良的Li +导体提升动力学性能。
在任选的实施方案中，三元前驱体材料的颗粒在1吨压力下的碎裂率≤50％；可选≤25％。例如，三元前驱体材料的颗粒在1吨压力下的碎裂率≤24％、≤23％、≤22％或≤21％等。
三元前驱体材料的颗粒抗压后的碎裂率的测试方法为：首先，采用压实密度测试的方法利用外力加载颗粒受压环境，并将原粉末与受压粉末分袋保存；其次，将两袋粉送至激光粒度仪(Malvern Master Size 3000)检测，并输出指标：Dv 1，而后将数据代入碎裂率表达式ΔDv 1/Dv 1＝[Dv 1(受压前)-Dv 1(受压后)]/Dv 1(受压前)，计算可得相应数值。其中，D v1的物理定义是材料累计体积分布百分数达到1％时所对应的粒径。
根据本申请所述的三元前驱体材料，进一步限定了所述材料的颗粒抗压后的碎裂率，使获得的三元前驱体材料具有很高的机械强度，有利 于抑制烧结后的高镍三元正极材料在高温循环下的开裂，提升循环性能。
在任选的实施方案中，所述掺杂元素选自钨、锑、钽、钼、钇和镁元素的一种或多种；和/或所述掺杂元素的质量分数为1000～8000ppm，可选2000～6000ppm；和/或，所述掺杂元素为钨元素，优选以钨的氧化物的形式掺杂。
在任选的实施方案中，所述掺杂元素的质量分数可以理解为在所述外壳10～100nm范围内，掺杂元素占所有元素的质量分数，可由SEM(Scanning Electron Microscope，扫描电子显微镜)-EDX(Energy Dispersive X-Ray Spectroscopy，能量色散X射线光谱仪))联用检测：先在SEM中选定需要观测的外壳范围，然后切换探头至EDX模式，对选区进行单点或者面扫面，然后勾选可能的元素进行成分分析或其它类似方式得到。
根据本申请所述的三元前驱体材料，进一步限定了所述外壳的掺杂元素和所述掺杂元素的质量分数，所述元素在外壳的掺杂可以抑制三元前驱体材料101晶面的生长从而在高温烧结下促进三元前驱体材料001晶面的生长，有助于提高烧结后正极材料的克容量发挥。
在任选的实施方案中，所述内核直径为2μm～9μm；和/或，所述外壳厚度为0.5μm～4μm。
厚度测试：氩气抛光后的样品放入SEM中选用基准模式可以观察到所述样品的内核与外壳，通过仪器自带的标尺分别沿着颗粒中心径向至内核界限，标记为内核半径，内核直径＝内核半径×2，同理可得中心至外壳边缘距离为整体半径，外壳厚度＝整体半径-内核半径。按照该方法在样品的任意位置取30个颗粒进行测量后取平均值。
根据本申请所述的三元前驱体材料，进一步限定了其内核直径和外壳厚度，有助于烧结出高克容量发挥与粉体抗压强度兼容的高镍三元正极材料。
在任选的实施方案中，所述三元前驱体材料的粒径D v50为3μm～17μm，优选为6μm～10μm；和/或所述三元前驱体材料的粒度SPAN值≤0.65，优选为≤0.45。
平均粒径D v50可以参照标准GB/T 19077.1-2016，使用激光粒度分析仪(如Malvern Master Size 3000)测定。其中，D v10的物理定义是材料累计体积分布百分数达到10％时所对应的粒径；D v50的物理定义是材料累计体积分布百分数达到50％时所对应的粒径；D v90的物理定义是材料累计体积分布百分数达到90％时所对应的粒径。粒度SPAN为(D v90-D v50)/D v10。
根据本申请所述的三元前驱体材料，还限定了其粒径，有助于烧结出高压实密度的高镍三元正极材料，并且有利于烧结后正极材料的克容 量发挥。进一步地，还限定了其粒度分布，有利于提高烧结后的高镍三元正极材料的混锂均匀性，能够保证物理化学性质的均一；同时几乎没有细小颗粒与微粉的存在，可以有助于抑制高温下产气与颗粒碎裂。
在任选的实施方案中，所述三元前驱体材料的BET为4m 2/g～16m 2/g，优选为8m 2/g～12m 2/g。
材料的比表面积为本领域公知的含义，可以用本领域公知的仪器及方法进行测定，例如可以用氮气吸附比表面积分析测试方法测试，并用BET(Brunauer Emmett Teller)法计算得出，其中氮气吸附比表面积分析测试可以是通过美国康塔公司的NOVA 2000e型比表面积与孔径分析仪进行。作为具体的示例，测试方法如下：用称重后的空样品管取8.000g～15.000g材料，将材料搅拌均匀并称重，把样品管放入NOVA 2000e脱气站中脱气，称量脱气后的材料和样品管总质量，用总质量减去空样品管的质量计算得到脱气后材料的质量G。将样品管放入NOVA 2000e，测定不同相对压力下的氮气在材料表面的吸附量，基于布朗诺尔-埃特-泰勒多层吸附理论及其公式求得单分子层吸附量，进而计算出材料总表面积A，通过A/G计算得到材料的比表面积。
根据本申请所述的三元前驱体材料，进一步限定了三元前驱体材料的BET，有助于烧结出高克容量发挥与表面化学稳定性的高镍三元正极材料。
在任选的实施方案中，所述三元前驱体材料的001晶面衍射峰与101晶面衍射峰的强度之比为0.6～1.2，优选为0.9～1.1。
可以通过X射线粉末衍射仪(X′pert PRO)，依据X射线衍射分析法通则JIS K 0131-1996，得到X射线衍射谱图，然后根据E＝I (001)/I (101)得到三元前驱体材料的001晶面衍射峰与101晶面衍射峰的强度之比E，其中，I (001)为001晶面衍射峰峰面积，I (101)为101晶面衍射峰的峰面积。其中，001晶面所对应的2θ角为17.8°～22.8°；101晶面所对应的2θ角为36.8°～42.0°。
根据本申请所述的三元前驱体材料，进一步限定了三元前驱体材料的001晶面衍射峰与101晶面衍射峰的强度之比，有助于烧结出具有较高各向同性的高镍三元正极材料。
在任选的实施方案中，三元前驱体材料的一次粒子长宽比为2～8。
其中，一次粒子为团聚体中单个晶粒，其在扫描电子显微镜图片中通常为矩形，量取其长度与宽度的比值即为长宽比，按照该方法在样品的任意位置取30个颗粒进行测量后取平均值。
根据本申请所述的三元前驱体材料，进一步限定了三元前驱体材料掺杂元素的长宽比，使得在外壳中均匀掺杂有利于增强表面结构稳定性 与片层堆叠有序性的掺杂元素，对烧结后的高镍三元正极材料循环性能有改善效果。
在本文中，颗粒或粒子的长度指的是颗粒或粒子的最大尺寸。一次颗粒的形貌可以采用本领域公知的仪器和方法进行测定，如扫描电子显微镜(如日本Hitachi S-4800型)。
接下来说明本申请实施例提供的一种三元前驱体材料的制备方法。根据该制备方法能够制备得到上述任意一种三元前驱体材料。
本申请的制备方法与现有技术的不同之处在于，本申请的方法在S2步骤有成核与核生长两个步骤，能在核上合成出径向分布的外壳结构；并且本申请发现，通过将氨水的工作浓度限定为0.6～1mol/L，优选地0.65～0.75mol/L，并在合成过程中保持氨水的工作浓度不变，可以使得到的三元前驱体材料的形变层错率f D以及抗压后的碎裂率都显著降低，能够满足本申请的要求。
例如，本申请的方法包括以下步骤：
S1：提供混合盐溶液、碱液、氨水、掺杂元素的盐溶液和底液，其中所述混合盐溶液包含可溶性镍盐、钴盐与锰盐；
S2：在反应釜中加入纯水作为底液，控制反应温度，搅拌并将混合盐溶液、碱液和氨水合流泵入反应釜中，得到所述三元前驱体内核浆液；其中，维持pH为9.5～10.5以及氨水的工作浓度为0.6～1mol/L；
S3：搅拌并将掺杂元素的盐溶液、碱液和氨水合流泵入反应釜中，合成所述三元前驱体浆液，将其烘干，得到所述三元前驱体材料；
其中，维持pH为9.5～10.5以及氨水的工作浓度为6.5～1mol/L。
在任选的实施方案中，步骤S1中，所述可溶性镍盐选自硫酸镍、硝酸镍、乙酸镍的一种或多种。所述可溶性钴盐选自硫酸钴、草酸钴、硝酸钴、乙酸钴的一种或多种。所述可溶性锰盐选自硫酸锰、硝酸锰、乙酸锰的一种或多种。所述掺杂元素的盐溶液可以掺杂元素的硝酸盐溶液、碳酸盐溶液等等，例如钨盐选自钨酸钠、钨酸铵的一种或多种。
在任选的实施方案中，步骤S2中，在反应釜中加纯水作为底液，加入氨水和碱液调节底液中的pH9.5～10.5，氨水浓度为0.5～1mol/L，优选为0.65～0.75mol/L，开始搅拌，控制反应温度为65～85℃，将镍钴锰混合盐溶液、碱液、氨水按照一定的流量合流泵入反应釜中，保持pH及氨浓度不变，反应时通以惰性气体保护，间歇地合成出体积分布窄小与平均粒径Dv50稳定的高镍三元前驱体内核浆液，得到所述三元前驱体内核浆液。
在任选的实施方案中，步骤S2中，反应前向所述底液中加入碱液和氨水，使底液pH为9.5～10.5，氨水的浓度为0.5～1mol/L，优选为0.65～0.75mol/L；和/或维持所述氨水的工作浓度为0.65～0.75mol/L；和/或 使反应温度为65～85℃；和/或搅拌速率为150～350rpm。
在任选的实施方案中，步骤S3中，将掺杂元素的盐溶液、碱液、氨水按照一定的流量合流泵入反应釜中，保持pH 9.5～10.5，氨水的浓度为0.5～1mol/L，优选为0.65～0.75mol/L，间歇地合成出体积分布较窄与平均粒径D v50稳定的核壳结构高镍三元前驱体浆液。
在任选的实施方案中，步骤S3中，维持所述氨水的工作浓度为0.65～0.75mol/L；和/或使反应温度为65～85℃；和/或搅拌速率为150～350rpm。
此申请的方法包含成核与核生长两个步骤，能在核上合成出径向分布的外壳结构，能明显改善烧结后的高镍三元正极材料的循环性能。并且申请的方法限定了氨水的工作浓度，并改变了进料方式，可以保证稳定合成高镍三元前驱体，避免浓度过高因系统的波动导致工艺变化。
接下来，本申请实施例还提供一种正极活性物质，正极活性物质是由上述的三元前驱体材料与锂复合而成。
作为示例，将上述的三元前驱体材料与锂盐混合并进行烧结处理，得到正极活性物质。
三元前驱体材料与锂盐可以放入犁刀混、高混机或者斜试混料机来进行混合。将混合后的物料加入气氛烧结炉中进行烧结。可选地，烧结气氛为空气气氛或氧气气氛；烧结温度为700～900℃，烧结时间为10～20h。
锂盐可以为氧化锂(Li 2O)、磷酸锂(Li 3PO 4)、磷酸二氢锂(LiH 2PO 4)、醋酸锂(CH 3COOLi)、氢氧化锂(LiOH)、碳酸锂(Li 2CO 3)及硝酸锂(LiNO 3)中的一种或多种，但并不限于此。
在任选的实施方案中，所述正极活性物质Li/Me摩尔比为0.9～1.1，Me为镍、钴、锰。
在一些实施例中，还可以将烧结产物进行破碎处理并筛分，以获得具有优化的粒径分布及比表面积的正极活性物质。其中对破碎的方式并没有特别的限制，可根据实际需求进行选择，例如使用颗粒破碎机。
根据本申请的方法获得得正极活性物质，为核壳结构，其中内核孔隙均匀且颗粒呈径向分布，外壳掺杂元素均匀分布，既可以提供较高的克容量发挥，又可以保护活性材料表面受到电解液副反应产物的腐蚀提高高温循环寿命，还能作为优良的Li +导体提升动力学性能抑制阻抗的增长。
正极极片
本申请实施例第二方面提供一种正极极片，正极极片采用本申请实施例第一方面的正极活性物质。
由于采用了本申请实施例第一方面的正极活性物质，本申请实施例的正极极片能使二次电池同时兼顾较高的克容量和循环性能。
具体地，正极极片包括正极集流体以及设置于正极集流体至少一个表面上的正极活性物质层。例如，正极集流体在自身厚度方向上包括相对的两个表面，正极活性物质层层叠设置于正极集流体的两个表面中的任意一者或两者上。
正极活性物质层包括本申请实施例第一方面的正极活性物质。
另外，正极活性物质层中还可以包括导电剂和粘结剂。本申请对正极活性物质层中的导电剂及粘结剂的种类不做具体限制，可以根据实际需求进行选择。
作为示例，导电剂可以为石墨、超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中一种或多种；粘结剂可以为丁苯橡胶(SBR)、水性丙烯酸树脂(water-based acrylic resin)、羧甲基纤维素(CMC)、聚偏二氟乙烯(PVDF)、聚四氟乙烯(PTFE)、聚乙烯醇缩丁醛(PVB)、乙烯-醋酸乙烯酯共聚物(EVA)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物、含氟丙烯酸树脂及聚乙烯醇(PVA)中的一种或多种。
正极集流体可以采用具有良好导电性能及力学性能的金属箔材或多孔金属板，其材质可以为铝、铜、镍、钛、银及它们各自的合金中的一种或多种。正极集流体例如为铝箔。
正极极片可以按照本领域常规方法制备。例如将正极活性物质、导电剂及粘结剂分散于溶剂中，溶剂可以是N-甲基吡咯烷酮(NMP)或去离子水，形成均匀的正极浆料，将正极浆料涂覆在正极集流体上，经烘干、辊压等工序后，得到正极极片。
锂离子二次电池
本申请实施例第三方面提供一种锂离子二次电池，锂离子电池包括正极极片、负极极片、隔离膜和电解质，其中正极极片为本申请实施例第二方面的正极极片。
由于采用了本申请实施例第一方面的正极活性物质，使得锂离子二次电池同时兼顾较高的克容量和循环性能。
上述负极极片可以是金属锂片。
上述负极极片还可以是包括负极集流体以及设置于负极集流体至少一个表面上的负极活性物质层。例如，负极集流体在自身厚度方向上包括相对的两个表面，负极活性物质层层叠设置于负极集流体的两个表面中的任意一者或两者上。
负极活性物质层包括负极活性材料。本申请实施例对负极活性材 料的种类不做具体地限制，可以根据实际需求进行选择。作为示例，负极活性材料可以是天然石墨、人造石墨、中间相微碳球(MCMB)、硬碳、软碳、硅、硅-碳复合物、SiO m(0＜m＜2，如m＝1)、Li-Sn合金、Li-Sn-O合金、Sn、SnO、SnO 2、尖晶石结构的钛酸锂Li 4Ti 5O 12、Li-Al合金及金属锂中的一种或多种。
负极活性物质层还可以包括导电剂和粘结剂。本申请实施例对负极活性物质层中的导电剂和粘结剂的种类不做具体限制，可以根据实际需求进行选择。作为示例，导电剂为石墨、超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的一种或多种；粘结剂为丁苯橡胶(SBR)、聚偏二氟乙烯(PVDF)、聚四氟乙烯(PTFE)、聚乙烯醇缩丁醛(PVB)、水性丙烯酸树脂(water-based acrylic resin)及羧甲基纤维素(CMC)中的一种或多种。
负极活性物质层还可选地包括增稠剂，例如羧甲基纤维素(CMC)。
负极集流体可以采用具有良好导电性能及力学性能的金属箔材或多孔金属板，其材质可以为铜、镍、钛、铁及它们各自的合金中的一种或多种。负极集流体例如为铜箔。
负极极片可以按照本领域常规方法制备。例如将负极活性材料、导电剂、粘结剂及增稠剂分散于溶剂中，溶剂可以是N-甲基吡咯烷酮(NMP)或去离子水，形成均匀的负极浆料，将负极浆料涂覆在负极集流体上，经烘干、辊压等工序后，得到负极极片。
本申请实施例的锂离子二次电池，电解质可以采用固体电解质，如聚合物电解质、无机固态电解质等，但并不限于此。电解质也可以采用电解液。作为上述电解液，包括溶剂和溶解于溶剂中的锂盐。
其中，溶剂可以为非水有机溶剂，例如碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、甲酸甲酯(MF)、乙酸甲酯(MA)、乙酸乙酯(EA)、乙酸丙酯(PA)、丙酸甲酯(MP)、丙酸乙酯(EP)、丙酸丙酯(PP)、丁酸甲酯(MB)及丁酸乙酯(EB)中的一种或多种，优选为两种以上。
锂盐可以为LiPF 6(六氟磷酸锂)、LiBF 4(四氟硼酸锂)、LiClO 4(高氯酸锂)、LiAsF 6(六氟砷酸锂)、LiFSI(双氟磺酰亚胺锂)、LiTFSI(双三氟甲磺酰亚胺锂)、LiTFS(三氟甲磺酸锂)、LiDFOB(二氟草酸硼酸锂)、LiBOB(双草酸硼酸锂)、LiPO 2F 2(二氟磷酸锂)、LiDFOP(二氟草酸磷酸锂)及LiTFOP(四氟草酸磷酸锂)中的一种或多种，例如为LiPF 6(六氟磷酸锂)、LiBF 4(四氟硼酸锂)、LiBOB(双草酸硼酸锂)、LiDFOB(二氟草酸硼酸锂)、LiTFSI(双三氟甲磺酰亚胺 锂)及LiFSI(双氟磺酰亚胺锂)中的一种或多种。
电解液中还可选地含有其它添加剂，例如碳酸亚乙烯酯(VC)、碳酸乙烯亚乙酯(VEC)、氟代碳酸乙烯酯(FEC)、二氟碳酸乙烯酯(DFEC)、三氟甲基碳酸乙烯酯(TFPC)、丁二腈(SN)、己二腈(ADN)、戊二腈(GLN)、己烷三腈(HTN)、1，3-丙烷磺内酯(1，3-PS)、硫酸乙烯酯(DTD)、甲基二磺酸亚甲酯(MMDS)、1-丙烯-1，3-磺酸内酯(PST)、4-甲基硫酸亚乙酯(PCS)、4-乙基硫酸亚乙酯(PES)、4-丙基硫酸亚乙酯(PEGLST)、硫酸丙烯酯(TS)、1，4-丁烷磺内酯(1，4-BS)、亚硫酸亚乙酯(DTO)、二甲基亚硫酸酯(DMS)、二乙基亚硫酸酯(DES)、磺酸酯环状季铵盐、三(三甲基硅烷)磷酸酯(TMSP)及三(三甲基硅烷)硼酸酯(TMSB)中的一种或多种，但并不限于此。
本申请实施例的锂离子二次电池对隔离膜没有特别的限制，可以选用任意公知的具有电化学稳定性和机械稳定性的多孔结构隔离膜，例如玻璃纤维、无纺布、聚乙烯(PE)、聚丙烯(PP)及聚偏二氟乙烯(PVDF)中的一种或多种的单层或多层薄膜。
将正极极片和负极极片交替层叠设置，并在正极极片与负极极片之间设置隔离膜以起到隔离的作用，得到电芯，也可以是经卷绕后得到电芯。将电芯置于外壳中，注入电解液，并封口，得到锂离子二次电池。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，二次电池可包括外包装。该外包装可用于封装上述电极组件及电解质。
在一些实施方式中，二次电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，如聚丙烯(PP)、聚对苯二甲酸丁二醇酯(PBT)、聚丁二酸丁二醇酯(PBS)等中的一种或几种。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。如图1是作为一个示例的方形结构的二次电池5。
在一些实施方式中，参照图2，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53用于盖设所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔。电解液浸润于电极组件52中。二次电池5所含电极组件52的数量可以为一个或几个，可根据需求来调节。
在一些实施方式中，二次电池可以组装成电池模块，电池模块所 含二次电池的数量可以为多个，具体数量可根据电池模块的应用和容量来调节。
图3是作为一个示例的电池模块4。参照图3，在电池模块4中，多个二次电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个二次电池5进行固定。
可选地，电池模块4还可以包括具有容纳空间的外壳，多个二次电池5容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以根据电池包的应用和容量进行调节。
图4和图5是作为一个示例的电池包1。参照图4和图5，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2用于盖设下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
用电装置
本申请的实施方式还提供一种用电装置，所述用电装置包括本申请的二次电池、电池模块、电池包中的至少一种。所述二次电池、电池模块或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以但不限于是移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等。
所述用电装置可以根据其使用需求来选择二次电池、电池模块或电池包。
图6是作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对高功率和高能量密度的需求，可以采用电池包或电池模块。
作为另一个示例的用电装置可以是手机、平板电脑、笔记本电脑等。该用电装置通常要求轻薄化，可以采用二次电池作为电源。
实施例
下述实施例更具体地描述了本申请公开的内容，这些实施例仅仅用于阐述性说明，因为在本申请公开内容的范围内进行各种修改和变化对本领域技术人员来说是明显的。除非另有声明，以下实施例中所报道的所有份、百分比、和比值都是基于重量计，而且实施例中使用的所有试剂都可商购获得或是按照常规方法进行合成获得，并且可直接使用而无需进一步处理，以及实施例中使用的仪器均可商购获得。
三元前驱体材料的制备
掺杂元素为钨，所述钨元素在外壳中的掺杂浓度为6000ppm。
制备方法包括：
采用硫酸镍、硫酸钴、硫酸锰按照摩尔比Ni∶Co∶Mn＝8.5∶1∶0.5配置成浓度为1.5mol/L的混合盐溶液，采用钨酸钠配置浓度为0.75mol/L的钨盐溶液，采用浓度为5mol/L的NaOH溶液作为碱液，氨水浓度为2mol/L。
在20L控制结晶反应釜中加入10L去离子水，加入一定量浓氨水使氨浓度为0.65mol/L，并加入一定量NaOH溶液使pH为10，得到底液。
在N 2保护气氛下，将底液加热至75℃并维持，在350rpm搅拌转速下，将混合盐溶液、碱液、氨水溶液并流加入底液中，其中混合盐溶液的流速不变，控制反应溶液的pH为10，氨水浓度为0.65mol/L，直至得到D v50＝4μm后，停止泵入，得到所述三元前驱体内核浆液；
继续流加钨盐溶液、碱液、氨水溶液，控制反应溶液的pH为10，氨水浓度为0.65mol/L，得到核壳结构的三元前驱体浆液，并经洗涤、干燥，得到三元前驱体材料。
测定所述三元前驱体材料的内核直径、外壳厚度、Dv50、粒度SPAN值、一次性粒子长宽比、BET等参数。
正极活性物质的制备
将所得三元前驱体材料与LiOH·H 2O按Li/Me摩尔比1∶1进行混合均匀，然后在纯氧气氛下，在箱式炉中于800℃烧结15h，经破碎、过筛即可得到正极活性物质。
电解液的制备
将EC、DEC、DMC按照体积比1∶1∶1进行混合后，得到溶剂，再将锂盐LiPF 6溶解于上述溶剂中，获得电解液，其中LiPF 6的浓度为1mol/L。
扣式电池的制备
将上述制备的正极活性材料、导电炭黑及粘结剂PVDF按照重量比90∶5∶5分散至溶剂N-甲基吡咯烷酮(NMP)中进行混合均匀，得到正极浆料；将正极浆料均匀涂布于正极集流体铝箔上，经烘干、冷压后，得到正极极片。
在扣电箱中，将正极极片、隔离膜及金属锂片依次层叠设置，并注入上述电解液，组装得到扣式电池。
全电池的制备
将上述制备的正极活性材料、导电剂乙炔黑及粘结剂PVDF按照重量比94∶3∶3分散至溶剂NMP中进行混合均匀，得到正极浆料；将正极 浆料均匀涂布于正极集流体铝箔上，经烘干、冷压后，得到正极极片。
将负极活性材料人造石墨、硬碳、导电剂乙炔黑、粘结剂丁苯橡胶(SBR)、增稠剂碳甲基纤维素钠(CMC)按照重量比90∶5∶2∶2∶1分散至去离子水中进行混合均匀，得到负极浆料；将负极浆料均匀涂布于负极集流体铝箔上，经烘干、冷压后，得到负极极片。
以聚乙烯(PE)多孔聚合薄膜作为隔离膜。将正极极片、隔离膜、负极极片按顺序叠好得到裸电芯，将裸电芯置于外包装中，注入上述电解液并封装，得到全电池。
实施例2～7
与实施例1不同的是，改变三元前驱体材料的制备步骤中的相关参数，并调整了掺杂元素含量。测试所获得的三元前驱体材料的形变层错率和碎裂率，并测定了所述三元前驱体材料的内核直径、外壳厚度、Dv50、粒度SPAN值、一次性粒子长宽比、BET等参数，具体详见表1和表2；其中表1为所述三元前驱体材料的制备步骤中相关参数，表2为得到的三元前驱体材料的相关参数。
实施例8～10
与实施例1不同的是，改变了所述掺杂元素的种类，涉及多元素掺杂的实施例10，各掺杂元素含量基本相同，详见表1。测试所获得的三元前驱体材料的形变层错率和碎裂率，并测定了所述三元前驱体材料的内核直径、外壳厚度、Dv50、粒度SPAN值、一次性粒子长宽比、BET等参数，具体详见表1和表2；其中表1为所述三元前驱体材料的制备步骤中相关参数，表2为得到的三元前驱体材料的相关参数。
实施例11～27
与实施例1不同的是，改变三元前驱体材料的制备步骤中的相关参数，并调整了掺杂元素含量。测试所获得的三元前驱体材料的形变层错率和碎裂率，并测定了所述三元前驱体材料的内核直径、外壳厚度、Dv50、粒度SPAN值、一次性粒子长宽比、BET等参数，具体详见表1和表2；其中表1为所述三元前驱体材料的制备步骤中相关参数，表2为得到的三元前驱体材料的相关参数。
对比例1～4
与实施例1不同的是，改变正极活性材料的制备步骤中的相关参数使得所述材料的形变层错率或碎裂率改变；测试所获得的三元前驱体材料的形变层错率和碎裂率，并测定了所述三元前驱体材料的内核直径、外壳厚度、Dv50、粒度SPAN值、一次性粒子长宽比、BET等参数，具体详见表1和表2；其中表1为所述三元前驱体材料的制备步骤中相关参数，表2为得到的三元前驱体材料的相关参数。
对比例9
与实施例1不同的是，未加入掺杂元素。
采用硫酸镍、硫酸钴、硫酸锰按照摩尔比Ni∶Co∶Mn＝8∶1∶1配置成浓度为1.5mol/L的混合盐溶液，采用浓度为5mol/L的NaOH溶液作为碱液，氨水浓度为2mol/L。
在20L控制结晶反应釜中加入10L去离子水，加入一定量浓氨水使氨浓度为0.65mol/L，并加入一定量NaOH溶液使pH为10，得到底液。
在N 2保护气氛下，将底液加热至70℃并维持，在150rpm搅拌转速下，将混合盐溶液、碱液、氨水溶液并流加入底液中，其中混合盐溶液的流速不变，控制反应溶液的pH为10，氨水浓度为0.65mol/L，直至得到D v50＝4.5μm后，停止泵入，并经洗涤、干燥，得到三元前驱体材料。
测试所获得的三元前驱体材料的形变层错率和碎裂率，并测定了所述三元前驱体材料的内核直径、外壳厚度、Dv50、粒度SPAN值、一次性粒子长宽比、BET等参数，具体详见表1和表2；其中表1为所述三元前驱体材料的制备步骤中相关参数，表2为得到的三元前驱体材料的相关参数。
测试部分
形变层错率f D：采用Bruker D8 Discovery设备，对三元前驱体材料进行X射线衍射图谱测试，在2θ角度为10°～70°的范围内慢速扫描，扫描速度优选0.5°/min，获得X射线衍射图谱。其次，将上述X射线衍射谱图拟合，得到的(001)、(101)、(102)衍射峰相关参数带入至以下表达式：
Figure PCTCN2021141873-appb-000002
其中，B (101)是前驱体(101)衍射峰的半峰宽，B (102)是前驱体(102)衍射峰的半峰宽，D (001)是前驱体(001)衍射峰的晶粒度，随后计算便可得到相应数值。
碎裂率：采用压实密度测试的方法利用外力加载颗粒受压环境，并将原粉末与受压粉末分袋保存；其次，将两袋粉送测激光粒度仪(Malvern Master Size 3000)检测，并输出指标：Dv 1，而后将数据代入碎裂率表达式ΔDv 1/Dv 1＝[Dv 1(受压前)-Dv 1(受压后)]/Dv 1(受压前)，计算可得相应数值。其中，D v1的物理定义是材料累计体积分布百分数达到1％时所对应的粒径。
全电池容量：将全电池在常温下按照恒电流的方式进行1/3C充电至4.25V，并以1/3C的恒电流放电至2.8V，所得即为1/3C克容量。
全电池首效：全电池容量测试中，其放电容量与充电容量之比即为首次库伦效率，也即全电池首效。
全电池45℃循环测试：将全电池在45℃的高低温箱内进行1C恒 电流的持续充放电测试，并在30圈时记录容量，其与首圈的容量比值即为30cls容量保持率；在30圈时记录其高SOC状态下的直流内阻(DCR)数值，其与首圈的DCR比值减去1即为30cls DCR增长率。测试部分结果详见表3。
Figure PCTCN2021141873-appb-000003
Figure PCTCN2021141873-appb-000004
Figure PCTCN2021141873-appb-000005
Figure PCTCN2021141873-appb-000006
Figure PCTCN2021141873-appb-000007
表3
Figure PCTCN2021141873-appb-000008
Figure PCTCN2021141873-appb-000009
通过实施例1-7发现，通过控制三元前驱体材料制备过程中内核合成过程，也就是S2的反应参数，可以使所述三元前驱体材料的形变层错率f D≤4％。形变层错率的降低使得三元前驱体材料的有序度与结构稳定性提高，进而提升了二次电池的循环性能。进一步地，申请人发现，通过掺杂元素，在烧结后不仅可以保护活性材料表面受到电解液副反应产物的腐蚀提高高温循环性能，还能作为优良的Li +导体提升动力学性能。
通过实施例8-27可以发现，所述三元前驱体材料中各参数满足预定关系，能够进一步保证正极活性材料兼具较高的结构稳定性；通过限定所述材料的颗粒抗压后的碎裂率，使获得的三元前驱体材料具有很高的机械强度，有利于抑制烧结后的高镍三元正极材料在高温循环下的开裂，更进一步提升了循环性能。
对比例1-8无法满足制备过程中的各种反应条件，使得所述三元前驱体材料的形变层错率较高，不利于烧结后正极材料的克容量发挥，也不利于提升电池的循环性能。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并且可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (17)

  1. 一种三元前驱体材料，包括内核与外壳，其特征在于：
    (1)所述内核分子式为Ni xCo yMn 1-x-y(OH) 2±a，其中：0.8≤x＜1.0，0＜y＜0.2，0＜a＜0.2；
    所述外壳包含掺杂元素；
    (2)所述三元前驱体材料的形变层错率f D≤4％。
  2. 根据权利要求1所述的三元前驱体材料，其中，所述三元前驱体材料的颗粒在1吨压力下的碎裂率≤50％；可选≤25％。
  3. 根据权利要求1或2所述的三元前驱体材料，其中，所述掺杂元素选自钨、锑、钽、钼、钇和镁元素的一种或多种；和/或
    所述掺杂元素的质量分数为1000～8000ppm，可选2000～6000ppm。
  4. 根据权利要求1至3中中任一项所述的三元前驱体材料，其中，所述内核直径为2μm～9μm；和/或，
    所述外壳厚度为0.5μm～4μm。
  5. 根据权利要求1至4中任一项所述的三元前驱体材料，其中，所述三元前驱体材料的粒径Dv50为3μm～17μm，优选为6μm～10μm；和/或
    所述三元前驱体材料的粒度SPAN值≤0.65，优选为≤0.45。
  6. 根据权利要求1至5中任一项所述的三元前驱体材料，其中，所述三元前驱体材料的BET为4m 2/g～16m 2/g，优选为8m 2/g～12m 2/g。
  7. 根据权利要求1至6中任一项所述的三元前驱体材料，其中，所述三元前驱体材料的001晶面衍射峰与101晶面衍射峰的强度之比为0.6～1.2，优选为0.9～1.1。
  8. 根据权利要求1至7中任一项所述的三元前驱体材料，其中，三元前驱体材料的一次粒子长宽比为2～8。
  9. 一种三元前驱体材料的制备方法，其中，所述方法包括以下步骤：
    S1：提供混合盐溶液、碱液、氨水、掺杂元素的盐溶液，其中所述混合盐溶液包含可溶性镍盐、钴盐与锰盐；
    S2：在反应釜中加入纯水作为底液，控制反应温度，搅拌并将混合盐溶液、碱液和氨水合流泵入反应釜中，得到所述三元前驱体内核浆液；其中，维持pH以及氨水的工作浓度不变；
    S3：将掺杂元素的盐溶液、碱液和氨水合流泵入反应釜中，合成所述三元前驱体浆液，烘干并烧结，得到所述三元前驱体材料；其中，维持pH以及氨水的浓度不变；
    其中，所述三元前驱体材料包括内核与外壳，所述内核分子式为Ni xCo yMn 1-x-y(OH) 2±a，其中：0.8≤x＜1.0，0＜y＜0.2，0＜a＜0.2；所述外壳 包含掺杂元素；并且，所述三元前驱体材料的形变层错率f D≤4％。
  10. 根据权利要求9所述的方法，其中，S2中，pH为9.5～10.5，所述氨水的工作浓度为0.6～1mol/L，可选0.65～0.75mol/L；和/或
    和/或
    反应温度为65～85℃；和/或
    搅拌速率为150～350rpm。
  11. 根据权利要求9或10所述的方法，其中，S3中，pH为9.5～10.5，所述氨水的工作浓度为0.65～0.75mol/L。
  12. 一种正极活性物质，包括由权利要求1-8中任一项所述的三元前驱体材料制备；或
    由根据权利要求9-11中任一项所述的方法制备获得的三元前驱体材料。
  13. 根据权利要求13所述的正极活性物质，其中，Li/Me摩尔比为0.9～1.1，Me为镍、钴、锰。
  14. 一种二次电池，包括根据权利要求12或13所述的正极活性物质。
  15. 一种电池模块，其中，包括根据权利要求14所述的二次电池。
  16. 一种电池包，其中，包括根据权利要求14所述的二次电池或根据权利要求15所述的电池模块。
  17. 一种用电装置，包括根据权利要求14所述的二次电池、根据权利要求15所述的电池模块、根据权利要求16所述的电池包中的至少一种。
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105765770A (zh) * 2013-11-22 2016-07-13 住友金属矿山株式会社 非水系电解质二次电池用正极活性物质及其制造方法、以及非水系电解质二次电池
JP2017199591A (ja) * 2016-04-28 2017-11-02 Ｂａｓｆ戸田バッテリーマテリアルズ合同会社 非水電解質二次電池用の正極活物質粒子及びその製造方法、並びにそれを用いた非水電解質二次電池
CN111244459A (zh) * 2020-01-21 2020-06-05 华东理工大学 高镍正极材料、镍钴前驱体材料及制备方法、锂离子电池
CN112607788A (zh) * 2020-12-14 2021-04-06 荆门市格林美新材料有限公司 一种制备窄粒度分布镍钴锰三元前驱体的方法
CN112670473A (zh) * 2020-12-23 2021-04-16 中伟新材料股份有限公司 三元前驱体及其制备方法、锂离子电池正极材料和锂离子电池

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105765770A (zh) * 2013-11-22 2016-07-13 住友金属矿山株式会社 非水系电解质二次电池用正极活性物质及其制造方法、以及非水系电解质二次电池
JP2017199591A (ja) * 2016-04-28 2017-11-02 Ｂａｓｆ戸田バッテリーマテリアルズ合同会社 非水電解質二次電池用の正極活物質粒子及びその製造方法、並びにそれを用いた非水電解質二次電池
CN111244459A (zh) * 2020-01-21 2020-06-05 华东理工大学 高镍正极材料、镍钴前驱体材料及制备方法、锂离子电池
CN112607788A (zh) * 2020-12-14 2021-04-06 荆门市格林美新材料有限公司 一种制备窄粒度分布镍钴锰三元前驱体的方法
CN112670473A (zh) * 2020-12-23 2021-04-16 中伟新材料股份有限公司 三元前驱体及其制备方法、锂离子电池正极材料和锂离子电池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4231384A4 *

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