Positive electrode active material composition, positive electrode plate, secondary battery, and electric device

Abstract

The invention relates to a positive active material composition, a positive pole piece, a secondary battery and an electric device. The positive electrode active material composition comprises a ternary material and a lithiated organic material; the chemical formula of the ternary material is LiNi < x > Co < y > Mn < z > O < 2 >, xlt; 1, 0lt; yt; Yt; 1, 0lt; zlt, zlt; x + y + z = 1; the chemical formula of the lithiated organic material is LiX. According to the positive electrode active material composition provided by the invention, through the synergistic effect of the ternary material and the lithiated organic material, on one hand, the lithiated organic material enhances the electronic conductivity and improves the energy density of the battery; on the other hand, the large pi-pi conjugated structure of the lithiated organic material can adsorb gas generated in the cyclic process of the ternary material, so that the swelling risk of the battery is reduced, and the cycle performance of the battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a positive electrode active material composition, a positive electrode sheet, a secondary battery, and an electrical device. Background Art

[0002] In recent years, with the increasingly wide application range of lithium-ion batteries, lithium-ion batteries are widely used in energy storage power systems such as hydraulic, thermal, wind, and solar power stations, as well as in multiple fields such as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, and aerospace. Among them, ternary materials, as positive electrode materials, can meet the performance requirements such as long life and low-temperature discharge of lithium-ion batteries, and have gradually received wide attention.

[0003] However, the energy density of ternary batteries using ternary materials as positive electrode materials needs to be improved. In addition, ternary materials are prone to side reactions during cycling to generate gas, increasing the risk of battery thermal runaway. Summary of the Invention

[0004] Based on this, it is necessary to provide a positive electrode active material composition, a positive electrode sheet, a secondary battery, and an electrical device to improve the energy density of ternary batteries, reduce gas generation, improve interface stability, and thus improve the cycle performance of the batteries.

[0005] The first aspect of the present application provides a positive electrode active material composition, which includes: a ternary material and a lithiated organic material; the chemical formula of the ternary material is LiNi x Co y Mn z O2, where 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1; the chemical formula of the lithiated organic material is LiX, where X is selected from at least one of the polymers having the structural general formula shown in formula (I):

[0006]

[0007] Formula (I);

[0008] In formula (I), Ar is connected to the adjacent pyrazine ring in the form of a fused ring, and Ar is selected from one of the following groups:

[0009] 、 。

[0010] In some embodiments, the polymer includes a compound having the structural general formula shown in formula (I-1):

[0011]

[0012] Formula (I-1).

[0013] In some embodiments, the degree of polymerization n of the polymer is an integer from 100 to 150.

[0014] In some embodiments, at least part of the lithiated organic material is coated on the surface of the ternary material.

[0015] In some embodiments, the mass ratio of the ternary material to the lithiated organic material is (99:1) to (65:35).

[0016] The second aspect of the present application provides a positive electrode plate, which includes: a positive electrode current collector; a positive electrode active material layer disposed on at least one side surface of the positive electrode current collector, and the positive electrode active material layer includes the positive electrode active material composition provided in the first aspect above.

[0017] The third aspect of the present application provides a secondary battery, which includes the positive electrode plate provided in the second aspect above.

[0018] In some embodiments, the secondary battery is a solid-state battery, and the solid-state battery includes a solid electrolyte membrane.

[0019] In some embodiments, the solid electrolyte membrane includes at least one of an oxide solid electrolyte, a polymer solid electrolyte, and a halide solid electrolyte.

[0020] The fourth aspect of the present application provides an electrical device, which includes the secondary battery provided in the third aspect above.

[0021] Compared with the traditional technology, the present application has at least the following beneficial effects:

[0022] The positive electrode active material composition provided by the present application, through the synergistic effect of the ternary material and the lithiated organic material, on the one hand, the lithiated organic material has a large π-π conjugate structure with multiple electron centers, which enhances the electronic conductivity, and the nitrogen atom in the lithiated organic material has a lone pair of electrons, which can serve as the active site of the redox reaction. The active sites of the lithiated organic material are alternately distributed, which can reduce the steric hindrance and improve the energy density of the ternary battery; on the other hand, the large π–π conjugate structure of the lithiated organic material makes the intermolecular interaction weak, which can adsorb the gas generated during the cycle and storage of the ternary material, thereby reducing the risk of battery swelling. The large π–π conjugate structure is also beneficial to improving the thermal stability of the material, reducing the risk of battery thermal runaway, and improving the safety performance of the battery. The lithiated organic material has a flexible molecular chain, so that after ion insertion / extraction, the volume and structure of the material do not change significantly, which is beneficial to relieve the interfacial stress, thereby improving the cycle performance of the battery. Specific Embodiments

[0023] Reference will now be made in detail to embodiments of the present application, one or more examples of which are described below. Each example is provided by way of explanation and not limitation of the present application. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the scope or spirit of the present application. For example, features described or illustrated as part of one embodiment can be used in another embodiment to yield a still further embodiment.

[0024] Accordingly, it is intended that the present application cover such modifications and variations that fall within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present application are disclosed in the following detailed description or are apparent therefrom. Those of ordinary skill in the art should understand that this discussion is only a description of exemplary embodiments and is not intended to limit the broader aspects of the present application.

[0025] In the present application, among the technical features described in an open-ended manner, there are included closed technical solutions composed of the listed features, as well as open technical solutions containing the listed features.

[0026] In the present application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are considered continuous and include the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when the range refers to integers, it includes every integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0027] If there is no special indication, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0028] If there is no special indication, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0029] If there is no special indication, all steps of the present application can be carried out sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out sequentially, or can also include steps (b) and (a) carried out sequentially. For example, when it is mentioned that the method may further include step (c), it means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0030] Unless otherwise specified, the terms "comprising" and "including" mentioned in this application are open-ended and can also be closed-ended. For example, the terms "comprising" and "including" can mean that other components not listed may also be included or comprised, or that only the listed components are included or comprised.

[0031] Unless otherwise specified, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or present) and B is false (or absent); A is false (or absent) while B is true (or present); or both A and B are true (or present).

[0032] The first aspect of this application provides a positive electrode active material composition, which includes a ternary material and a lithiated organic material. The chemical formula of the ternary material is LiNi x Co y Mn z O2, where 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1. The chemical formula of the lithiated organic material is LiX, where X is selected from at least one of the polymers having the general structural formula shown in formula (I):

[0033]

[0034] Formula (I);

[0035] In formula (I), Ar is connected to the adjacent pyrazine ring in the form of a fused ring, and Ar is selected from one of the following groups:

[0036] , .

[0037] For the positive electrode active material composition provided by this application, through the synergistic effect of the ternary material and the lithiated organic material, on the one hand, the lithiated organic material has a large π-π conjugate structure with multiple electron centers, which enhances the electronic conductivity, and the nitrogen atoms in the lithiated organic material have lone pairs of electrons and can serve as active sites for redox reactions. The active sites of the lithiated organic material are alternately distributed, which can reduce steric hindrance and improve the energy density of the battery; on the other hand, the large π-π conjugate structure of the lithiated organic material enables weak intermolecular interactions, which can adsorb the gases generated during the cycling and storage of the ternary material, thereby reducing the risk of battery swelling. The large π-π conjugate structure is also beneficial to improving the thermal stability of the material, reducing the risk of battery thermal runaway, and improving the safety performance of the battery. The lithiated organic material has a flexible molecular chain, so that after ion insertion / extraction, the volume and structure of the material do not change significantly, which is conducive to relieving the interfacial stress and thus improving the cycling performance of the battery.

[0038] It is understandable that the lithiated polymer organic material has good compatibility with the ternary material, which is beneficial to activating active sites and forming lithium ion transport channels, thereby improving the electrochemical performance of the material. In addition, the lithiated organic material has flexible molecular segments that can wrap around the surface of the ternary material, which is beneficial to improving the gas adsorption efficiency, relieving interfacial stress, reducing interfacial impedance, and improving the cycling performance of the battery.

[0039] In some embodiments, the polymer comprises a compound having the general structural formula shown in formula (Ⅰ-1):

[0040]

[0041] Formula (Ⅰ-1).

[0042] In some embodiments, the degree of polymerization n of the polymer is an integer from 100 to 150. Exemplarily, the degree of polymerization n of the polymer can be, but is not limited to, 100, 110, 120, 130, 135, 140, 145, 150. Within the above range of the degree of polymerization, the polymer molecular chain has an appropriate length and flexibility, so that it can not only ensure good processing performance, but also have good electrical conductivity, while effectively wrapping the ternary material particles, forming a stable interfacial structure, improving the gas adsorption efficiency, relieving interfacial stress, reducing interfacial impedance, and improving the cycling performance of the battery.

[0043] It is understandable that during the preparation of the polymer, controlling the proportion of the oxidant in the solvent, the temperature of the polymerization reaction, and the reaction time can achieve the control of the degree of polymerization n of the polymer. For example, increasing the proportion of the oxidant, decreasing the reaction temperature, and increasing the reaction time can increase the degree of polymerization n of the polymer.

[0044] In some embodiments, at least part of the lithiated organic material is coated on the surface of the ternary material. Coating the lithiated organic material on the surface of the ternary material is beneficial to improving the gas adsorption efficiency, relieving interfacial stress, reducing interfacial impedance, and improving the cycling performance of the battery.

[0045] In some of these embodiments, the mass ratio of the ternary material to the lithiated organic material is (99:1) to (65:35). Exemplarily, the mass ratio of the ternary material to the lithiated organic material can be, but is not limited to, 99:1, 98:2, 97:3, 96:4, 95:5, 94:6, 93:7, 92:8, 91:9, 90:10, 89:11, 88:12, 87:13, 86:14, 85:15, 84:16, 83:17, 82:18, 81:19, 80:20, 79:21, 78:22, 77:23, 76:24, 75:25, 70:30, 69:31, 68:32, 67:33, 66:34, 65:35. Within the above mass ratio range, it is possible to improve the energy density, safety performance, and cycle stability of the battery while ensuring a high energy density of the battery.

[0046] In some of these embodiments, LiX is obtained by a lithiation reaction of X with a lithiating agent. The lithiation reaction introduces lithium ions at the active sites in X, such that LiX can not only serve as a lithium source to provide lithium ions for the electrode, but also directly participate in the electrochemical reaction, thereby increasing the specific capacity of the cathode material.

[0047] In some of these embodiments, the lithiating agent is selected from one or more of LiOH, LiNO3, and Li2CO3.

[0048] In some of these embodiments, the precursor compound of X includes pyrene-4,5,9,10-tetrone. Pyrene-4,5,9,10-tetrone is a highly conjugated polycyclic compound, and as a precursor of X, it can introduce side chains by reacting with an ortho-amino structure, regulating the side chains to have an alternating active site structure, thereby obtaining a polymer X with multiple electron centers and a large π-π conjugated structure.

[0049] The second aspect of the present application provides a positive electrode tab, which includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is disposed on at least one surface of the positive electrode current collector, and the positive electrode active material layer includes the positive electrode active material composition provided in the first aspect above.

[0050] In some of these embodiments, the positive electrode current collector is selected from metal foils and composite current collectors; the composite current collector has a sandwich-like laminated structure, with the middle polymer layer mainly composed of materials such as high molecular insulating resins, and metal layers deposited on both sides of the middle polymer layer by electroplating, electroless plating or other methods. Schematically, the high molecular resin includes polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyether ether ketone, polyimide, polyamide, polyethylene glycol, polyamide-imide, polycarbonate, cyclic polyolefin, polyphenylene sulfide, polyvinyl acetate, polytetrafluoroethylene, polymethylene naphthalene, polyvinylidene fluoride, polyethylene naphthalate, polypropylene carbonate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride-co-trifluorochloroethylene), silicone, vinylon, polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyether nitrile, polyurethane, polyphenylene ether, polyester, polysulfone and its derivatives, sodium carboxymethyl cellulose, styrene-butadiene rubber, fluororubber, polyvinyl alcohol or polyvinylidene fluoride, etc., one or more of them. The material of the metal layer is selected from at least one of aluminum, copper, nickel, cobalt, tungsten, tin, lead, iron, silver or gold. Further, the positive electrode current collector is an aluminum foil.

[0051] In some of these embodiments, the positive electrode active material layer further includes a conductive agent, and the conductive agent plays a role in collecting microcurrents between the positive electrode active materials and between the positive electrode active materials and the positive electrode current collector.

[0052] In some of these embodiments, the mass percentage of the conductive agent in the positive electrode active material layer is 1% - 10%.

[0053] In some of these embodiments, the conductive agent includes graphite, such as natural graphite or artificial graphite; carbon materials, such as carbon black, acetylene black, Ketjen black, channel black, super-P and thermal cracking carbon black; conductive fibers, such as carbon fiber and metal fiber; conductive tubes, such as carbon nanotubes; metal powders, such as carbon fluoride powder, aluminum powder and nickel powder; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and polyphenylene derivatives. And in terms of improving conductivity, the conductive agent can preferably be super-P.

[0054] In some of these embodiments, the specific surface area of the conductive agent can be 80 m 2 / g - 200 m 2 / g, preferably 100m 2 / g - 150 m 2 / g.

[0055] In some of these embodiments, the positive electrode active material layer further contains a binder, and the binder can play a role in bonding the positive electrode active material and the conductive agent together; the mass percentage of the binder in the positive electrode active material layer is 1% - 10%.

[0056] In some embodiments, the thickness of the positive electrode active material layer can be from 30 μm to 400 μm, such as 30 μm, 40 μm, 50 μm, 80 μm, 110 μm, 200 μm, 300 μm, 400 μm, and is preferably from 50 μm to 110 μm.

[0057] In some embodiments, the secondary battery further includes a negative electrode tab. Wherein, the negative electrode active material layer at least includes a negative electrode active material.

[0058] In some embodiments, there is no particular limitation on the negative electrode active material in the embodiments of the present application, as long as it is a substance that can electrochemically absorb and release s-block metal ions such as lithium ions, sodium ions, potassium ions, and magnesium ions, such as carbonaceous materials, metal compound materials, or their oxides, carbides, nitrides, silicides, sulfides, phosphides, etc. These substances can be used alone, or two or more of them can be arbitrarily combined and used.

[0059] In some embodiments, a carbon material can be selected as the negative electrode active material, and specifically, one or more of the following can be selected: graphite, needle coke, amorphous carbon, carbonaceous mesophase, carbon fiber, and carbon materials with low graphitization degree. Among them, graphite can include natural graphite, artificial graphite, etc. In addition, materials obtained by coating them with carbon materials such as amorphous carbon and graphitized materials can also be used. Amorphous carbon includes, but is not limited to, particles obtained by firing the overall mesophase and particles obtained by infusibilizing a carbon precursor and then firing. As particles of carbonaceous substances with low graphitization degree, particles obtained by firing an organic substance at a temperature generally lower than 2500 °C can be cited.

[0060] In some embodiments, non-metallic materials that can be used as the negative electrode active material also include silicon and its compounds, such as Si, SiO x (0 ≤ x < 2) or silicon-carbon materials. Since silicon-containing materials are prone to expansion, are likely to fall off from the negative electrode current collector, and have poor conductivity, they are often used in combination with carbon materials, such as core-shell structures with a carbon coating layer.

[0061] In some embodiments, metal elements and metal compound materials can also be selected as the negative electrode active material, such as compounds containing metals or metalloids such as Li, Ag, Al, Bi, Cu, Ga, Ge, In, Ni, Pb, Sb, Si, Sn, Sr, Zn, etc.

[0062] The third aspect of the present application provides a secondary battery, which includes the positive electrode tab provided in the second aspect above.

[0063] In some of these embodiments, the secondary battery is a solid-state battery, and the solid-state battery includes a solid electrolyte membrane. The ternary material is an inorganic rigid material, and the lithiated organic material is a flexible material. The lithiated organic material coats the surface of the ternary particle material through its flexible chain segments, which can construct a new ion / electron pathway, optimize the interface between the positive electrode and the solid electrolyte, and reduce the interfacial impedance of the solid-state battery. Therefore, the positive electrode active material composition provided by this application is particularly suitable for solid-state batteries.

[0064] In some of these embodiments, the solid electrolyte membrane includes at least one of an oxide solid electrolyte, a polymer solid electrolyte, and a halide solid electrolyte.

[0065] In some of these embodiments, the oxide solid electrolyte includes at least one of garnet-type lithium lanthanum zirconium oxide (LLZO), NASICON-type, and LISICON-type.

[0066] The NASICON-type oxide solid electrolyte is AM′M″P3O 12 a sodium superionic conductor in terms of molecular formula. In the molecular formula, A is usually a monovalent transport cation, such as at least one alkali metal ion including Na, K, Li, etc. The M′ and M″ positions can be either divalent or trivalent cations (such as at least one of Zn 2+ , Mg 2+ , Ni 2+ , Cr 3+ , Al 3+ , Sc 3+ , Fe 3+ , In 3+ and Y 3+ etc.), or can be tetravalent or pentavalent cations (such as at least one of Ti 4+ , Zr 4+ , Ge 4+ , Sn 4+ , V 5+ , Nb 5+ , As 5+ etc.). In addition, P 5+ can also be doped or substituted by other high-valence ions such as Si 4+ , V 5+ , Nb 5+ etc. Exemplarily, the NASICON-type oxide solid electrolyte can be, but is not limited to, Na3Zr2Si2PO 12 .

[0067] The LISICON-type oxide solid electrolyte is a lithium ion conductor, which contains a solid three-dimensional anion framework. The framework ions provide a transport channel for migratable lithium ions. The Li outside the framework +In the interstitial position, it can conduct electricity and migrate. Interstitial lithium ions have good proton exchange ability. In the exemplary embodiment, this LISICON-type oxide solid electrolyte can be but is not limited to Li 4-x Ge 1-x P x S4, where x can be from 0.01 to 0.99. In the exemplary embodiment, the value of x can be typical but non-limiting values such as 0.01, 0.05, 0.1, 0.5, 0.75, 0.9, 0.99, etc.

[0068] In some of these embodiments, the polymer solid electrolyte is selected from one or more of the following: polyacrylonitrile (PAN), polyethylene oxide (PEO), polysiloxane (PSO), polyvinylidene fluoride (PVDF), polyvinylidene fluoride - hexafluoropropylene (PVDF - HFP), polymethyl methacrylate (PMMA), and their derivatives.

[0069] In some of these embodiments, the halide solid electrolyte includes LiaMY4, LiaMY6, and LiaMY8, where M can include at least one of metals such as Mn, Zn, Fe, Al, Yb, etc., and Y can include at least one of halogens F, Cl, Br, I.

[0070] The fourth aspect of the present application provides an electrical device, which includes the secondary battery provided in the above third aspect.

[0071] The electrical device of the present application is not particularly limited and can be any electrical device known in the prior art. For example, the electrical device can include but is not limited to laptop computers, pen input computers, mobile computers, e - book players, mobile phones, portable fax machines, portable copiers, portable printers, head - mounted stereo headphones, video recorders, liquid crystal TVs, hand - held cleaners, portable CD players, mini - discs, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, automobiles, motorcycles, power - assisted bicycles, bicycles, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries, and lithium - ion capacitors.

[0072] The present application will be further described below in conjunction with specific preparation examples, examples, and comparative examples.

[0073] Preparation Example 1

[0074] This preparation example provides a preparation method of a lithiated organic material.

[0075] S1. Weigh 15 g of pyrene-4,5,9,10-tetrone and 20 g of 2,3,7,8-phenazine tetramine, add them to 400 mL of a mixed solvent of acetic acid and ethanol (volume ratio 1:1), and heat to 120 °C for reaction; after the reaction, filter, wash, and dry to obtain the polymer shown in formula (I-1), where n = 125.

[0076]

[0077] Formula (I-1)

[0078] S2. Grind LiOH (analytical pure, purity > 98%) to the micron level, and add LiOH at 1.3 times the amount of active sites in the compound shown in formula (I) above during homogenization (i.e., add 1.3 mol of LiOH for 1 mol of active sites), and ball-mill and mix for 30 minutes to make LiOH evenly dispersed and react with the active sites, control the water content of the mixed slurry (< 1 wt%), and after the reaction, wash and dry to obtain the lithiated organic material.

[0079] Preparation Example 2

[0080] The preparation method of the lithiated organic material in this preparation example is basically the same as that in Preparation Example 1, except that:

[0081] In step S1, replace 20 g of 2,3,7,8-phenazine tetramine with 10 g of 1,2,4,5-benzenetetramine to obtain the compound shown in formula (I-2). Where n = 125.

[0082]

[0083] Formula (I-2)

[0084] Preparation Example 3

[0085] The preparation method of the lithiated organic material in this preparation example is basically the same as that in Preparation Example 1, except that:

[0086] In step S1, the volume ratio of acetic acid to ethanol is 8:10, so that the degree of polymerization n of the obtained polymer is 100.

[0087] Preparation Example 4

[0088] The preparation method of the lithiated organic material in this preparation example is basically the same as that in Preparation Example 1, except that:

[0089] In step S1, the volume ratio of acetic acid to ethanol is 12:10, so that the degree of polymerization n of the obtained polymer is 150.

[0090] Preparation Example 5

[0091] The preparation method of the lithiated organic material in this preparation example is basically the same as that in Preparation Example 1, except that:

[0092] In step S1, the volume ratio of acetic acid to ethanol is 6:10, so that the degree of polymerization n of the prepared polymer is 50.

[0093] Preparation Example 6

[0094] The preparation method of the lithiated organic material in this preparation example is basically the same as that in Preparation Example 1, except that:

[0095] In step S1, the volume ratio of acetic acid to ethanol is 14:10, so that the degree of polymerization n of the prepared polymer is 200.

[0096] Example 1

[0097] Positive electrode active material composition:

[0098] Ternary material LiNi 0.83 Co 0.12 Mn 0.05 O2 and the lithiated organic material prepared in Preparation Example 1, wherein the mass ratio of the ternary material to the lithiated organic material is 80:20.

[0099] Positive electrode sheet:

[0100] The positive electrode active material composition, conductive agent carbon black (Super-P), and binder polyvinylidene fluoride (PVDF) are added to the solvent N-methylpyrrolidone (NMP) in a mass ratio of 96:3:1 to prepare a positive electrode slurry, and then the positive electrode slurry is coated on a 13-μm-thick positive electrode current collector aluminum foil and dried to form a positive electrode active material layer, thus obtaining a positive electrode sheet.

[0101] Secondary battery:

[0102] The secondary battery in this example is a solid-state battery. The solid electrolyte membrane includes a PEO polymer solid electrolyte. The negative electrode of the solid-state battery is a lithium metal negative electrode.

[0103] Example 2

[0104] The preparation methods of the positive electrode active material composition, positive electrode sheet, and secondary battery in this example are basically the same as those in Example 1, except that:

[0105] The lithiated organic material in the positive electrode active material composition is the lithiated organic material prepared in Preparation Example 2.

[0106] Example 3

[0107] The preparation methods of the positive electrode active material composition, positive electrode sheet, and secondary battery in this example are basically the same as those in Example 1, except that:

[0108] The mass ratio of the ternary material to the lithiated organic material in the positive electrode active material composition is 99:1.

[0109] Example 4

[0110] The preparation methods of the positive electrode active material composition, the positive electrode sheet, and the secondary battery in this example are basically the same as those in Example 1, except that:

[0111] The mass ratio of the ternary material to the lithiated organic material in the positive electrode active material composition is 65:35.

[0112] Example 5

[0113] The preparation methods of the positive electrode active material composition, the positive electrode sheet, and the secondary battery in this example are basically the same as those in Example 1, except that:

[0114] The mass ratio of the ternary material to the lithiated organic material in the positive electrode active material composition is 60:40.

[0115] Example 6

[0116] The preparation methods of the positive electrode active material composition, the positive electrode sheet, and the secondary battery in this example are basically the same as those in Example 1, except that:

[0117] The lithiated organic material is replaced by the polymer material prepared in Preparation Example 3. Among them, the degree of polymerization n of the polymer is 100.

[0118] Example 7

[0119] The preparation methods of the positive electrode active material composition, the positive electrode sheet, and the secondary battery in this example are basically the same as those in Example 1, except that:

[0120] The lithiated organic material is replaced by the polymer material prepared in Preparation Example 4. Among them, the degree of polymerization n of the polymer is 150.

[0121] Example 8

[0122] The preparation methods of the positive electrode active material composition, the positive electrode sheet, and the secondary battery in this example are basically the same as those in Example 1, except that:

[0123] The lithiated organic material is replaced by the polymer material prepared in Preparation Example 5. Among them, the degree of polymerization n of the polymer is 50.

[0124] Example 9

[0125] The preparation methods of the positive electrode active material composition, the positive electrode sheet, and the secondary battery in this example are basically the same as those in Example 1, except that:

[0126] The lithiated organic material was replaced with the polymer material prepared in Preparation Example 6. Among them, the degree of polymerization n of the polymer was 200.

[0127] Comparative Example 1

[0128] Positive electrode active material:

[0129] Ternary material LiNi 0.83 Co 0.12 Mn 0.05 O2.

[0130] Positive electrode sheet:

[0131] The positive electrode active material, the conductive agent conductive carbon black (Super-P), and the binder polyvinylidene fluoride (PVDF) were added to the solvent N-methylpyrrolidone (NMP) in a mass ratio of 96:3:1 to prepare a positive electrode slurry. Then, the positive electrode slurry was coated on a positive electrode current collector aluminum foil with a thickness of 13 μm, and dried to form a positive electrode active material layer, thereby obtaining a positive electrode sheet.

[0132] Secondary battery:

[0133] The secondary battery in this comparative example was a solid-state battery. The solid electrolyte membrane included a PEO polymer solid electrolyte. The negative electrode of the solid-state battery was a lithium metal negative electrode.

[0134] Comparative Example 2

[0135] Positive electrode active material:

[0136] The lithiated organic material prepared in Preparation Example 1.

[0137] Positive electrode sheet:

[0138] The positive electrode active material, the conductive agent conductive carbon black (Super-P), and the binder polyvinylidene fluoride (PVDF) were added to the solvent N-methylpyrrolidone (NMP) in a mass ratio of 96:3:1 to prepare a positive electrode slurry. Then, the positive electrode slurry was coated on a positive electrode current collector aluminum foil with a thickness of 13 μm, and dried to form a positive electrode active material layer, thereby obtaining a positive electrode sheet.

[0139] Secondary battery:

[0140] The secondary battery in this comparative example was a solid-state battery. The solid electrolyte membrane included a PEO polymer solid electrolyte. The negative electrode of the solid-state battery was a lithium metal negative electrode.

[0141] Performance test

[0142] (1) Electrochemical performance test

[0143] The secondary batteries of the above-mentioned examples and comparative examples were subjected to 1 / 3C / 1 / 3C charge-discharge cycle tests (the voltage test range for charge and discharge was 2.8V - 4.25V) under the conditions of 45°C and a restraint force of 10MPa. The test results are shown in Table 1.

[0144] (2)Gas generation test

[0145] The secondary batteries of the above-mentioned examples and comparative examples were hung with a dynamometer and the batteries were completely immersed in silicone oil heated to 60°C. After the batteries were kept in a static state, the value of the dynamometer was read and recorded as F1. After 45 days of storage, the value of the dynamometer was read and recorded as F2. Combining Newton's theorem and Archimedes' buoyancy law: F1 - F2 = ρ 液 gV 电芯鼓胀 The gas generation volume of the battery core was obtained.

[0146] Table 1

[0147]

[0148] As shown in Table 1, by comparing Examples 1 - 9 and Comparative Examples 1 - 2, it can be seen that the positive electrode active material composition provided by the present application improves the energy density of the ternary battery, inhibits gas generation, and improves the cycle performance of the battery.

[0149] The technical features of the above-mentioned embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0150] The above-mentioned embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the technical concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A positive electrode active material composition, characterized in that, Comprising: ternary material and lithiated organic material; The chemical formula of the ternary material is LiNi x Co y Mn z O2, where 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1; The lithiated organic material includes LiX, wherein X is selected from at least one of polymers having the general structural formula shown in formula (Ⅰ): Formula (Ⅰ); In formula (Ⅰ), Ar is connected to the adjacent pyrazine ring in the form of a fused ring, and Ar is selected from one of the following groups: 、 。 2. The positive electrode active material composition according to claim 1, wherein The polymer includes a compound having the general structural formula shown in formula (Ⅰ-1): Formula (Ⅰ-1).

3. The positive electrode active material composition according to claim 1, characterized in that, At least part of the lithiated organic material is coated on the surface of the ternary material.

4. The positive electrode active material composition according to any one of claims 1 to 3, characterized in that, The degree of polymerization n of the polymer is an integer of 100 to 150.

5. The cathode active material composition according to any one of claims 1 to 3, characterized in that, The mass ratio of the ternary material to the lithiated organic material is (99:1) to (65:35).

6. A positive electrode sheet, characterized in that, Comprising: positive current collector; positive active material layer, disposed on at least one side surface of the positive current collector, and the positive active material layer includes the positive active material composition according to any one of claims 1 to 5.

7. A secondary battery, characterized in that, Including the positive electrode sheet according to claim 6.

8. The secondary battery according to claim 7, characterized in that, The secondary battery is a solid-state battery, and the solid-state battery includes a solid electrolyte membrane.

9. The secondary battery according to claim 8, characterized in that, The solid electrolyte membrane includes at least one of an oxide solid electrolyte, a polymer solid electrolyte, and a halide solid electrolyte.

10. An electrical device, characterized in that, Including the secondary battery according to any one of claims 7 to 9.

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