Battery cell, battery device, and electric device

Abstract

Provided are a battery cell (5), a battery device and an electric device. The battery cell (5) comprises a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer provided on at least one surface of the positive electrode current collector. The positive electrode material layer comprises a positive electrode active material and metal oxide particles. The positive electrode active material comprises a lithium-rich manganese-based oxide material. The metal oxide comprises at least one of CeO2, TiO2, Cu2O, CuO, WO3, NiO, Fe2O3, Co3O4, MnO, ZnO, MnO2, and MoO3. The mass ratio of the metal oxide particles in the positive electrode material layer is W1, wherein 0.001％≤W1≤10％. By using metal oxide particles in a positive electrode material of a lithium-rich manganese-based battery system, the negative effects caused by active oxygen are significantly reduced, thereby improving the cycle performance and storage performance of the battery.

Description

Battery monomer, battery device and electric device

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411088283.X, filed on August 8, 2024, entitled “Battery monomer, battery device and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery device and an electric device. BACKGROUND

[0004] In recent years, with the development of lithium ion secondary battery technology, lithium ion secondary batteries are widely used in energy storage power systems such as hydroelectric, thermal, wind and solar power stations, and in many fields such as electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. Due to the great development of lithium ion secondary batteries, higher requirements are put forward for their fast charging performance, cycle performance and safety performance, etc.

[0005] In order to further improve the energy density of lithium ion batteries, it is necessary to develop high-energy-density positive electrode materials. The lithium-rich manganese-based oxide positive electrode material has a special oxygen anion redox mechanism, and its discharge specific capacity is as high as 300 mAh / g, which is much higher than that of lithium iron phosphate and ternary material positive electrode materials. However, oxygen is easily released in the form of irreversible active oxygen under high-voltage charging state, causing instability of the material structure, and the active oxygen released will react with the electrolyte, resulting in poor interface stability of the material, and thus poor cycle performance and storage performance. SUMMARY

[0006] The purpose of the present application is to provide a battery monomer, a battery device and an electric device, which adopts a lithium-rich manganese-based oxide positive electrode material system, and by cooperating with metal oxide particles, the active oxygen generated by the positive electrode can be consumed, and a good interface is formed in the positive electrode, which is beneficial to improve the cycle performance and storage performance of the battery.

[0007] To this end, the present application provides a battery monomer, comprising a positive electrode sheet, a negative electrode sheet and a separator, the positive electrode sheet comprising a positive electrode current collector and a positive electrode material layer arranged on at least one surface of the positive electrode current collector; the positive electrode material layer comprises a positive electrode active material and a metal oxide particle; the positive electrode active material comprises a lithium-rich manganese-based oxide material; the metal oxide comprises at least one of CeO2, TiO2, Cu2O, CuO, WO3, NiO, Fe2O3, Co3O4, MnO, ZnO, MnO2, and MoO3;

[0008] In the positive electrode material layer, the mass ratio of the metal oxide particles is W1, and 0.001%≤W1≤10%.

[0009] The lithium-rich manganese-based positive electrode material is prone to escape in the form of active oxygen in an irreversible manner under a high-voltage charging state due to a special oxygen anion redox mechanism, causing instability of the material structure. The escaped active oxygen can react with the electrolyte, resulting in poor interface stability of the material, and further causing poor cycle performance and storage performance. The metal oxide particles are used as additives in the positive electrode material layer. The oxygen vacancies in the metal oxide particles can stabilize the active oxygen and avoid the escape of the active oxygen, thereby avoiding the side reaction of the electrolyte caused by the active oxygen escaping from the surface of the positive electrode material during high-voltage cycling and storage. When the mass ratio of the metal oxide particles in the positive electrode material layer is within the above range, the generation amount of oxygen free radicals can be reduced, and the positive and negative electrode interfaces can be improved, thereby improving the cycle performance and high-temperature storage performance of the battery.

[0010] In some embodiments, 0.025%≤W1≤5%.

[0011] By further adjusting the mass ratio of the metal oxide particles in the positive electrode material layer to be 0.025%-5%, the improvement of the cycle and storage performance of the battery can be improved.

[0012] In some embodiments, the particle size Dv50 of the metal oxide particles is 5-50 nm.

[0013] In the embodiments of the present application, the small particle size of the metal oxide particles, for example, 5-50 nm, is used to enhance the reaction between the metal oxide and the active oxygen, and better consume the active oxygen, thereby avoiding the decomposition of the electrolyte caused by the oxygen free radicals.

[0014] In some embodiments, the particle size Dv50 of the metal oxide particles is 5-15 nm.

[0015] By using the above-mentioned particle size of the metal oxide particles, the reactivity between the metal oxide and the active oxygen is further improved, which is beneficial to improving the cycle performance of the battery.

[0016] In some embodiments, the molecular formula of the lithium-rich manganese-based oxide material is xLi2MnO3·(1-x)LiNi y Co z Mn a M 1-y-z-a O r A 2-rwherein 0 < x < 1, 0≤y≤1, 0≤z≤1, 0≤a≤1, 0 < r < 2, 0 < y + z + a < 1; M is at least one of Mg, B, Al, V, Ti, Zr, Sn and Mo, and A is at least one of F, S, N and Cl.

[0017] When the above lithium-rich manganese-based oxide material is used, not only does it have a high energy density, but the active oxygen generated thereby can be almost completely consumed by the metal oxide, which is conducive to improving the cycle performance and high-temperature storage performance of the battery.

[0018] In some embodiments, the ratio of x in the molecular formula of the lithium-rich manganese-based oxide material and the mass ratio W1 of the metal oxide particles in the positive electrode material layer satisfy the following relationship: the ratio of x to W1 is 1-90000.

[0019] When the ratio of x to W1 is in the above range, the oxygen radicals generated by the lithium-rich manganese-based oxide material can react with an equivalent amount and an excess amount of the metal oxide, thereby better reducing the amount of active oxygen generated.

[0020] In some embodiments, the specific surface area of the lithium-rich manganese-based oxide material is 0.7m 2 / g-2.8m 2 / g.

[0021] The specific surface area of the lithium-rich manganese-based oxide material affects its ion conductivity and the intensity of the side reaction with the electrolyte. By making the specific surface area of the lithium-rich manganese-based oxide material in the above range, the electrode sheet has good ion conductivity, and at the same time, the side reaction of the material with the electrolyte is avoided as much as possible; thereby improving the long-term performance of the battery.

[0022] In some embodiments, the microstress of the lithium-rich manganese-based oxide material is 0.3%-3.0%.

[0023] By making the microstress of the lithium-rich manganese-based oxide material in the above range, the stress accumulation of the positive electrode material particles during the charge and discharge cycle process is reduced, the secondary ball breakage phenomenon caused by excessive stress of the material is improved, and the stability is improved.

[0024] In some embodiments, the negative electrode sheet includes a negative electrode active material, and the specific surface area of the negative electrode active material is 0.5m 2 / g-2.0m 2 / g.

[0025] When the metal oxide particles are applied, a SEI film of a certain thickness is formed on the surface of the negative electrode sheet. In this case, by appropriately reducing the surface area of the negative electrode active material to be within the above range, the contact area between the negative electrode active material and the electrolyte is reduced, thereby further reducing the side reaction of the electrolyte solvent on the surface of the negative electrode, and the cycle performance of the battery is improved.

[0026] In a second aspect of the present application, a battery device is provided, which includes the battery cell according to the first aspect of the present application.

[0027] In a third aspect of the present application, a power consuming device is provided, which includes the battery cell according to the first aspect of the present application, or the battery device according to the second aspect of the present application.

[0028] The above description is merely a summary of the technical solutions of the present application. In order to enable one skilled in the art to better understand the technical means of the present application, the contents of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are listed. BRIEF DESCRIPTION OF DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not meant to limit the present application. In the drawings:

[0030] FIG. 1 is a schematic view of a battery cell according to an embodiment of the present application;

[0031] FIG. 2 is an exploded view of the battery cell according to an embodiment of the present application shown in FIG. 1;

[0032] FIG. 3 is a schematic view of a battery module according to an embodiment of the present application;

[0033] FIG. 4 is a schematic view of a battery pack according to an embodiment of the present application;

[0034] FIG. 5 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 4;

[0035] FIG. 6 is a schematic view of a power consuming device using the battery cell according to an embodiment of the present application as a power source;

[0036] BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION

[0037] Exemplary embodiments of the present disclosure will be described in greater detail below. It should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thoroughly and completely understood, and will fully convey the scope of the present disclosure to those skilled in the art.

[0038] The ranges disclosed herein are defined by their lower and upper endpoints, given that a range is defined by selecting a lower limit and an upper limit, the selected lower limit and upper limit define the boundaries of a particular range. Ranges defined by endpoints can be either inclusive or exclusive without limitations, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if minimum range values of 1 and 2 are listed, and maximum range values of 3, 4, and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present application, unless otherwise stated, a numerical range "a-b" indicates a shorthand way of describing each and every intervening real number between the upper and lower endpoint values, a and b, wherein a and b are both real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed herein, "0-5" is merely a shorthand way of describing these numerical combinations. In addition, when a parameter is stated to be an integer ≥ 2, it is equivalent to disclose that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0039] All embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, if not specifically stated otherwise.

[0040] All technical features and optional technical features of the present application can be combined with each other to form new technical solutions, if not specifically stated otherwise.

[0041] All steps of the present application can be performed in sequence or randomly, preferably in sequence, if not specifically stated otherwise. For example, the method comprises steps (a) and (b) indicates that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, it is mentioned that the method can further comprise step (c), which indicates that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0042] If not specifically stated, the "comprising" and "including" mentioned in the present application represent open-ended, and can also be closed-ended. For example, the "comprising" and "including" can represent that other components not listed can also be included, or only the listed components can be included.

[0043] As a potential battery positive electrode material, the lithium-rich manganese-based oxide positive electrode material has a discharge specific capacity as high as 300 mAh / g due to a special oxygen anion redox mechanism, which is much higher than that of lithium iron phosphate and ternary materials, and has a good application prospect. However, the lithium-rich manganese-based oxide material is easy to escape in the form of irreversible active oxygen at a high-voltage charging state, causing instability of the material structure, and the escaped active oxygen will react with the electrolyte, resulting in poor interface stability of the material, and further causing poor cycle performance and storage performance.

[0044] The present application reduces or eliminates the effect of active oxygen by applying a metal oxide with a certain mass ratio in the lithium-rich manganese-based oxide positive electrode material system, thereby improving the cycle performance and storage performance of the battery.

[0045] The scheme described in the embodiments of the present application is applicable to a battery monomer, a battery device using the battery monomer, and a power consumption device using the battery monomer or the battery device.

[0046] Battery monomer

[0047] In the embodiments of the present application, the battery monomer can be a secondary battery, which refers to a battery monomer that can be activated by charging after discharging to continue to be used.

[0048] The battery monomer can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc. In some embodiments, the battery monomer is a lithium ion battery.

[0049] [Electrode assembly]

[0050] The battery monomer generally includes an electrode assembly. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator, and the separator is arranged between the negative electrode sheet and the positive electrode sheet. During the charging and discharging process of the battery monomer, active ions (such as lithium ions) are embedded and extracted between the positive electrode sheet and the negative electrode sheet. The separator arranged between the positive electrode sheet and the negative electrode sheet can prevent the positive and negative electrodes from short-circuiting, and at the same time, the active ions can pass through.

[0051] [Positive electrode sheet]

[0052] In some embodiments, a battery cell is provided, comprising a positive electrode sheet, a negative electrode sheet and a separator, the positive electrode sheet comprising a positive electrode current collector and a positive electrode material layer disposed on at least one surface of the positive electrode current collector; the positive electrode material layer comprising a positive electrode active material and metal oxide particles; the positive electrode active material comprising a lithium-rich manganese-based oxide material; the metal oxide comprising at least one of CeO2, TiO2, Cu2O, CuO, WO3, NiO, Fe2O3, Co3O4, MnO, ZnO, MnO2, MoO3.

[0053] In the positive electrode material layer, the mass percentage of the metal oxide particles is W1, and 0.001%≤W1≤10%.

[0054] The lithium-rich manganese-based positive electrode material is prone to escape in the form of active oxygen in an irreversible manner under a high-voltage charging state due to a special oxygen anion redox mechanism, causing instability of the material structure. The escaped active oxygen can also react with the electrolyte, resulting in poor interface stability of the material, and further causing poor cycle performance and storage performance. The application of metal oxide particles as additives in the positive electrode material layer can stabilize the active oxygen by means of oxygen vacancies in the metal oxide, thereby avoiding the escape of active oxygen and the side reaction of the electrolyte with the active oxygen escaped from the surface of the positive electrode material during high-voltage cycling and storage. When the mass percentage of the metal oxide in the positive electrode material layer is within the above range, the generation amount of oxygen free radicals can be reduced, and the positive and negative electrode interfaces can be improved, thereby improving the cycle performance and high-temperature storage performance of the battery.

[0055] The lithium-rich manganese-based oxide material is a composite positive electrode material based on Li2MnO3, which includes a Li2MnO3 phase. Compared with LiMn2O4 or pure layered LiMnO2 positive electrode materials, the Li / Mn molar ratio of this type of material is higher, and therefore it is generally referred to as a lithium-rich manganese-based material, a lithium-rich manganese-based oxide material, or a layered lithium-rich manganese-based compound, etc.

[0056] In some embodiments, 0.025%≤W1≤5%.

[0057] By further adjusting the mass percentage of the metal oxide particles in the positive electrode material layer to 0.025%-5%, the improvement of the cycle and storage performance of the battery can be improved.

[0058] In some embodiments, the mass ratio W1 of the metal oxide particles in the positive electrode material layer can be selected from about 0.001%, 0.01%, 0.02%, 0.025%, 0.03%, 0.04%, 0.05%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, etc.

[0059] In some embodiments, the particle size Dv50 of the metal oxide particles is 5-50 nm; for example, it can be selected from about 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc.

[0060] In the embodiments of the present application, the use of smaller metal oxide particle sizes, for example 5-50 nm, is beneficial to enhancing the reaction between the metal oxide and active oxygen, better consuming active oxygen, and avoiding the decomposition of electrolyte caused by oxygen free radicals and other adverse effects.

[0061] The particle size Dv50, also known as the median diameter or median particle size, refers to the particle size corresponding to the cumulative volume percentage of 50% of a sample; its physical meaning is that the particles with a particle size greater than it account for 50% by volume, and the particles with a particle size less than it also account for 50% by volume. Dv50 can be tested by methods known in the art. As an example, reference can be made to GB / T 19077-2016, and a Malvern laser particle size analyzer can be used for characterization testing, for example, a Malvern Mastersizer-3000 instrument can be used for testing.

[0062] In some embodiments, the particle size Dv50 of the metal oxide particles is 5-15 nm.

[0063] By applying the above-mentioned particle size of the metal oxide particles, the reactivity between the metal oxide particles and active oxygen is further improved, which is beneficial to improving the cycle performance of the battery.

[0064] In some embodiments, the molecular formula of the lithium-rich manganese-based oxide material is xLi2MnO3·(1-x)LiNi y Co z Mn a M 1-y-z-a O r A 2-rwherein 0 < x < 1, 0≤y≤1, 0≤z≤1, 0≤a≤1, 0 < r < 2, 0 < y + z + a < 1; M is at least one of Mg, B, Al, V, Ti, Zr, Sn and Mo, and A is at least one of F, S, N and Cl.

[0065] When the above-mentioned lithium-rich manganese-based oxide material is used, not only does it have a high energy density, but the active oxygen generated thereby can be almost completely consumed by the metal oxide, which is conducive to improving the cycle performance and high-temperature storage performance of the battery.

[0066] The content of the chemical formula of the positive electrode active material and the added elements can be measured by methods and devices known in the art. For example, measurement is performed by an inductively coupled plasma optical emission spectrometer (ICP-OES). As an example, the following steps can be followed: first, a certain mass (for example, 1 g) of material is weighed into a beaker, a certain volume (for example, 25 mL) of acid (for example, HNO3) solution of a certain concentration (for example, a concentration of 25% by volume) is added to the material to dissolve the positive electrode material, and a certain volume (for example, 475 mL) of deionized water is used to dilute the solution, and then the diluted solution is placed into an inductively coupled plasma optical emission spectrometer (for example, an ICAP 7400 from Thermo Fisher Scientific, USA) for analysis of the target elements, and the chemical formula of the positive electrode active material is calculated.

[0067] In some embodiments, the ratio of x in the molecular formula of the lithium-rich manganese-based oxide material and the mass ratio W1 of the metal oxide particles in the positive electrode material layer has the following ratio relationship: the ratio of x to W1 is 1-90000; for example, it can be selected from about 1, 2, 3, 4, 5, 6, 8, 10, 50, 100, 500, 1000, 1500, 2000, 2500, 3000, 3200, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, etc.

[0068] When the ratio of x to W1 is in the above range, the oxygen radicals generated by the lithium-rich manganese-based oxide material can react with an equivalent amount and an excess amount of metal oxide, thereby better reducing the amount of active oxygen generated.

[0069] In some embodiments, the specific surface area of the lithium-rich manganese-based oxide material is 0.7 m 2 / g-2.8 m 2 / g; for example, it can be selected from about 0.7 m 2 / g, 0.8 m 2 / g, 0.9 m2 / g, 1 m 2 / g, 1.1 m 2 / g, 1.2 m 2 / g, 1.3 m 2 / g, 1.4 m 2 / g, 1.5 m 2 / g, 1.6 m 2 / g, 1.7 m 2 / g, 1.8 m 2 / g, 1.9 m 2 / g, 2 m 2 / g, 2.1 m 2 / g, 2.2 m 2 / g, 2.3 m 2 / g, 2.4 m 2 / g, 2.5 m 2 / g, 2.6 m 2 / g, 2.7 m 2 / g, 2.8 m 2 / g, etc.

[0070] The specific surface area of the lithium-rich manganese-based oxide material affects its ion conductivity and the intensity of side reactions with electrolyte. Controlling the specific surface area of the lithium-rich manganese-based oxide material to be within the above range helps to improve the ion conductivity of the electrode sheet while minimizing the side reactions between the material and electrolyte, thereby improving the long-term performance of the battery.

[0071] In some embodiments, the microstress of the lithium-rich manganese-based oxide material is 0.3% to 3.0%; for example, it can be selected from about 0.3%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.7%, 3%, etc.

[0072] By controlling the microstress of the lithium-rich manganese-based oxide material to be within the above range, the stress accumulation of the positive electrode material particles during the charge and discharge cycle can be reduced, the secondary ball breakage phenomenon caused by excessive stress of the material can be improved, and the stability can be improved.

[0073] The microstress of the lithium-rich manganese-based oxide material can be calculated by methods and devices known in the art. For example, by X-ray diffraction pattern (XRD) test fitting. As an example, the following steps can be followed: set the XRD test conditions: use Cu target, set tube voltage (e.g. 40 V), set tube current (e.g. 40 mA), set scan speed (e.g. <2° / min), set 2 theta scan range (e.g. 15°-70°), set step size (e.g. 0.02°), set divergence slit (DS) (e.g. 1 mm), set anti-scattering slit (SS) (e.g. 8 mm), use graphite monochromator. After fitting the XRD spectrum, the microstress is obtained: MS = (Bhkl*Cosθhkl) / (4sinθhkl), where θhkl is the diffraction angle of the (hkl) crystal plane of the positive electrode material in the XRD diffraction pattern, and Bhkl is the half-height width of the (hkl) crystal plane of the positive electrode material in the XRD diffraction pattern.

[0074] In some embodiments, the positive current collector can employ a metal foil or a composite current collector. For example, as a metal foil, an aluminum foil can be employed. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) on a polymer material base material (e.g., a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0075] In some embodiments, the positive electrode material layer can further optionally include a binder. For example, the binder can include one or more than two combinations selected from the group consisting of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorine-containing acrylate resin.

[0076] In some embodiments, the positive electrode material layer can further optionally include a conductive agent. For example, the conductive agent can include one or more than two combinations selected from the group consisting of Super P, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers.

[0077] In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned positive electrode active material, metal oxide particles, and optionally a conductive agent, a binder, and any other components in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry on a positive electrode current collector, and after drying, cold pressing, etc., a positive electrode sheet can be obtained.

[0078] [Negative electrode sheet]

[0079] The negative electrode sheet includes a negative active material. In some embodiments, the negative electrode sheet includes a negative current collector and a negative material layer disposed on at least one surface of the negative current collector, the negative material layer including the negative active material.

[0080] In some embodiments, the specific surface area of the negative active material is 0.5 m 2 / g to 2.0 m 2 / g; for example, can be selected from about 0.5 m 2 / g, 0.6 m 2 / g, 0.7 m 2 / g, 0.8 m 2 / g, 0.9 m 2 / g, 1 m 2 / g, 1.1 m 2 / g, 1.2 m 2 / g, 1.3 m 2 / g, 1.4 m 2 / g, 1.5 m 2 / g, 1.6 m 2 / g, 1.7 m 2 / g, 1.8 m 2 / g, 1.9 m 2 / g, 2 m 2 / g, etc.

[0081] When metal oxide particles are applied, a SEI film of a certain thickness is formed on the surface of the negative electrode sheet. In this case, by appropriately reducing the surface area of the negative active material to be within the above range, the contact area of the negative active material with the electrolyte is reduced, and thus the side reaction of the electrolyte solvent on the surface of the negative electrode is further reduced, and the cycle performance of the battery is improved.

[0082] In some embodiments, the negative current collector can be a metal foil or a composite current collector. For example, as the metal foil, a copper foil can be used. The composite current collector can include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base layer (such as a base layer of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0083] In some embodiments, the negative active material layer can employ negative active materials for lithium ion batteries known in the art. For example, the negative active material includes one or more than two combinations selected from the group consisting of natural graphite, artificial graphite, meso-carbon microbead (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, Li-Sn alloy, Li-Sn-O alloy, Sn, SnO, SnO2, TiO2-Li4Ti5O 12 , Li-Al alloy.

[0084] In some embodiments, the negative active material layer can further optionally include a binder. For example, the binder can include one or more than two combinations selected from the group consisting of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS).

[0085] In some embodiments, the negative active material layer can further optionally include a conductive agent. For example, the conductive agent can include one or more than two combinations selected from the group consisting of Super P, acetylene black, carbon black, Ketjen black, carbon dot, carbon nanotube, graphene, carbon nanofiber.

[0086] In some embodiments, the negative active material layer can further optionally include other auxiliary agents. For example, the other auxiliary agent can be a thickening agent (such as sodium carboxymethyl cellulose (CMC-Na)).

[0087] In some embodiments, the negative electrode sheet can be prepared by dispersing the components of the negative active material layer described above, such as the negative active material, conductive agent, binder, and any other components, in a solvent (such as deionized water) to form a negative electrode slurry; coating the negative electrode slurry on a negative current collector, and after processes such as drying, cold pressing, etc., a negative electrode sheet can be obtained.

[0088] [Electrolyte]

[0089] In some embodiments, the battery cell further includes an electrolyte; the electrolyte functions to conduct ions between the positive electrode sheet and the negative electrode sheet. The type of electrolyte is not specifically limited in the present application and can be selected as needed. The electrolyte can be liquid, gel, or solid.

[0090] Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0091] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonimide, lithium bis-trifluoromethanesulfonimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro oxalato borate, lithium difluoro dioxalato borate, lithium difluoro dioxalato phosphate, and lithium tetrafluoro oxalato phosphate.

[0092] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyl sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be selected from an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and a crown ether.

[0093] In some embodiments, the electrolyte solution can also optionally include an additive. For example, the additive can include a negative electrode film-forming additive, a positive electrode film-forming additive, an additive capable of improving certain performance of the battery cell, such as an additive capable of improving overcharge / fast charge performance of the battery cell, an additive capable of improving high-temperature performance of the battery cell, an additive capable of improving low-temperature performance of the battery cell, and the like.

[0094] In some embodiments, the gel-type electrolyte includes a polymer as a skeleton network and can be used in combination with an ionic liquid-lithium salt.

[0095] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0096] As an example, the polymer of the polymer solid-state electrolyte can include a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid, cellulose, or the like.

[0097] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium-arsenic-phosphorus-sulfur, sulfur-silver-arsenic mineral), amorphous sulfide), and a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0098] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0099] [Separator]

[0100] In some embodiments, the electrode assembly further comprises a separator disposed between the positive electrode sheet and the negative electrode sheet.

[0101] In some embodiments, the separator is a separator film. The type of the separator film is not particularly limited in the present application, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0102] For example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can be applied to the surface of the separator film.

[0103] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive and negative electrodes.

[0104] [Structure of the electrode assembly]

[0105] The electrode assembly can have a wound structure, a stacked structure, or a hybrid structure of the wound and stacked structures.

[0106] In some embodiments, the electrode assembly has a wound structure. The positive electrode sheet and the negative electrode sheet are wound to form the wound structure.

[0107] In some embodiments, the electrode assembly has a stacked structure.

[0108] For example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked.

[0109] For example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet can be folded to form a plurality of folded sections stacked one on another, with one positive electrode sheet interposed between adjacent folded sections.

[0110] For example, both the positive electrode sheet and the negative electrode sheet can be folded to form a plurality of folded sections stacked one on another.

[0111] For example, a plurality of separators can be provided, each disposed between any adjacent positive electrode sheet or negative electrode sheet.

[0112] For example, the separators can be continuously provided and disposed between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0113] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, etc.

[0114] In some embodiments, the electrode assembly can be provided with tabs, which can guide the current out of the electrode assembly. The tabs can include positive tabs and negative tabs.

[0115] [Shell]

[0116] In some embodiments, the battery cell can include a shell. The shell can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. In some embodiments, the shell can be a sealed structure or a non-sealed structure. As an example, when the shell is a non-sealed structure, the shell serves to protect the electrode assembly, and a sealing bag is further included between the shell and the electrode assembly, which is used to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the shell is a sealed structure, it is used to encapsulate the electrode assembly and the electrolyte, etc.

[0117] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or other shapes of battery cells, including a square battery cell, a blade battery cell, a multi-prismatic battery cell (such as a hexagonal battery cell), etc. without specific limitation in the present application. For example, FIG. 1 is a square battery cell 5 as an example.

[0118] In some embodiments, referring to FIG. 2, the shell includes an end cap 53 and a shell body 51, the shell body 51 is provided with an opening, and the end cap 53 is provided on the opening. The shell body 51 can be provided with one or more openings. The end cap 53 can also be provided with one or more openings. The positive electrode sheet, the negative electrode sheet, and the separator can form the electrode assembly 52 through a winding process or a stacking process. The electrode assembly 52 is encapsulated in the accommodation cavity enclosed by the shell body 51 and the end cap 53. The electrolyte is impregnated in the electrode assembly 52.

[0119] [Electrode terminal]

[0120] In some embodiments, at least one electrode terminal is provided on the shell, and the electrode terminal is electrically connected with the tab. The electrode terminal can be directly connected with the tab, or indirectly connected with the tab through a current collecting member. The electrode terminal can be provided on the end cap or on the shell body.

[0121] [Pressure relief mechanism]

[0122] In some embodiments, a pressure relief mechanism is provided on the shell. The pressure relief mechanism is used to discharge the internal gas of the battery cell.

[0123] As an example, the battery cell is actuated to release internal pressure or temperature when the internal pressure or temperature reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism performs an action or a weak structure provided in the pressure relief mechanism is broken, thereby forming an opening or a passage for the internal pressure or temperature to be released. The threshold is designed differently according to design requirements. The threshold can depend on the material of one or more of the positive electrode, the negative electrode, the electrolyte, and the separator in the battery cell.

[0124] As an example, the pressure relief mechanism can be integrally formed with the housing.

[0125] As an example, the pressure relief mechanism can also be provided separately from the housing and connected thereto.

[0126] As used herein, "actuation" refers to the pressure relief mechanism performing an action or being activated to a certain state, thereby allowing the internal pressure and temperature of the battery cell to be released. The action performed by the pressure relief mechanism can include, but is not limited to, a component in the pressure relief mechanism moving to form an exhaust passage, at least a portion of the pressure relief mechanism breaking, shattering, tearing, or opening, and the like. When the pressure relief mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell are discharged as exhaust from the actuated part. In this way, the battery cell can be released at a controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0127] In some embodiments, when the housing is a non-sealed structure, the pressure relief mechanism can be provided as a through hole for discharging gas inside the battery cell.

[0128] As used herein, the exhaust from the battery cell includes, but is not limited to, electrolyte, dissolved or split positive and negative electrodes, fragments of the separator, high-temperature and high-pressure gas generated by reaction, flame, and the like.

[0129] Battery Apparatus

[0130] As used herein, the battery apparatus can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar.

[0131] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0132] As an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie. FIG. 3 is a battery module 4 as an example. Referring to FIG. 3, in the battery module 4, a plurality of battery cells 5 can be arranged in sequence along the length direction of the battery module 4. Of course, the battery cells can be arranged in any other manner.

[0133] In some embodiments, the battery device can be a battery pack, which includes a case and one or more battery cell assemblies accommodated in the case.

[0134] As an example, the battery cell assembly can be a battery module, which can be accommodated in the case by fixing the battery module in the case. FIG. 4 and FIG. 5 are a battery pack 1 as an example. Referring to FIG. 4 and FIG. 5, the battery pack 1 can include a case and a plurality of battery modules 4 arranged in the case. The case includes an upper case 2 and a lower case 3, and the upper case 2 can be placed on the lower case 3 to form an enclosed space for accommodating the battery modules 4. The plurality of battery modules 4 can be arranged in the battery case in any manner.

[0135] As an example, the battery cell assembly can also be accommodated in the case by directly fixing a plurality of battery cells in the case.

[0136] As an example, the case can include a first case and a second case. The first case and the second case are coupled so that an enclosed space is formed inside the case to accommodate the battery cell assembly. Here, the enclosed means covered or closed, which can be sealed or unsealed. The first case can be a top cover or a bottom plate.

[0137] As an example, the case can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame so that an enclosed space is formed inside the case to accommodate the battery cell assembly.

[0138] In some embodiments, the case can be a part of a chassis structure of a vehicle. For example, a part of the case can be at least a part of a floor of the vehicle, or a part of the case can be at least a part of a cross beam and a longitudinal beam of the vehicle.

[0139] Electric device

[0140] The technical solutions described in the embodiments of the present application are applicable to various battery cell using electric devices, for example, mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft including airplanes, rockets, space shuttles and spaceships, etc. FIG. 6 is an electric device as an example. The electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0141] Embodiment 1

[0142] The lithium ion battery cell is prepared as follows, and the related parameters and test results are shown in Table 1:

[0143] (1) Positive electrode sheet

[0144] The lithium-rich manganese-based oxide material 0.3Li2MnO3·0.7LiNi 0.4 Co 0.1 Mn 0.5 O2 (specific surface area of 1.8 m 2 / g, micro stress of 0.8%) as a positive electrode active material, metal oxide particles CeO2 (Dv50 of 8 nm), polyvinylidene fluoride (PVDF) as a binder, and acetylene black as a conductive agent are dissolved in a solvent N-methyl pyrrolidone (NMP) at a mass ratio of 96-(100×W1):(100×W1):2:2 (in the embodiment 1, W1 is 0.1%, so the above mass ratio is 95.9:0.1:2:2), and after being fully stirred and uniformly mixed, a positive electrode slurry is obtained. Then the positive electrode slurry is uniformly coated on the positive electrode current collector, and then after drying, cold pressing and slitting, a positive electrode sheet is obtained.

[0145] (2) Negative electrode sheet

[0146] The artificial graphite (specific surface area of 1.0 m 2 / g) as a negative electrode active material, acetylene black as a conductive agent, butadiene rubber (SBR) as a binder, and sodium carboxymethyl cellulose (CMC) as a thickening agent are dissolved in a solvent deionized water at a mass ratio of 95:2:2:1, and after being uniformly mixed, a negative electrode slurry is prepared. Then the negative electrode slurry is uniformly coated on the negative electrode current collector copper foil, and after drying, a negative electrode film is obtained, and then after cold pressing and slitting, a negative electrode sheet is obtained.

[0147] (3) Preparation of electrolyte

[0148] In an argon atmosphere glove box (H2O <0.1 ppm, O2 <0.1 ppm), 1 mol / L LiPF6 is dissolved in an organic solvent (EC / DMC / EMC = 1 / 1 / 1), and after being stirred uniformly, a corresponding electrolyte is obtained.

[0149] (4) Preparation of the separator film: a conventional polypropylene film was used as the separator film.

[0150] (5) Preparation of the lithium ion battery

[0151] The positive electrode sheet, the separator film, and the negative electrode sheet were stacked in order, with the separator film between the positive and negative electrode sheets to serve as a separator, and then wound to obtain an electrode assembly. The electrode assembly was placed in a battery case, dried, and then injected with an electrolyte, and then subjected to processes such as formation and standing to obtain a lithium ion battery.

[0152] Method for testing the physical property parameters of the positive and negative active materials:

[0153] 1. Specific surface area of the positive and negative active materials

[0154] 8-15 g of the sample to be tested was placed in a sample tube, and the initial mass of the sample to be tested was recorded. The weighed sample to be tested was placed in the device NOVA2000e. Then, the sample to be tested was degassed and heated to 200°C, and then maintained for 2 h. The mass of the sample to be tested after degassing was then recorded. The degassed sample to be tested was then reloaded into the device, and poured into liquid nitrogen for BET testing. The nitrogen pressure was set to 0.08-0.12 MPa, and the heating temperature was set to 40-350°C. After the test was completed, the specific surface area was read from the test results.

[0155] 2. Microstress of the positive active material

[0156] The microstress of the positive active material was determined by X-ray diffraction (XRD) test fitting. Specifically, the XRD test conditions were set as follows: a Cu target was used, the tube voltage was set to 40 V, the tube current was set to 40 mA, the scanning speed was set to <2° / min, the 2θ scanning range was set to 15°-70°, the step size was set to 0.02°, the emission slit (DS) was set to 1 mm, the anti-scattering slit (SS) was set to 8 mm, and a graphite monochromator was used. After fitting the XRD spectrum, the microstress was obtained: MS=(Bhkl*Cosθhkl) / (4sinθhkl), where θhkl is the diffraction angle of the (hkl) crystal plane of the positive active material in the XRD diffraction pattern, and Bhkl is the half-height width of the (hkl) crystal plane of the positive active material in the XRD diffraction pattern.

[0157] 3. Content of the added elements

[0158] The positive electrode material chemical formula and the content of the added element can be measured by methods and devices known in the art. For example, by an inductively coupled plasma optical emission spectrometer (ICP-OES). As an example, the following steps can be followed: first, weigh a certain mass (for example, 1 g) of the positive electrode material in a beaker, add a certain volume (for example, 25 mL) of an acid (for example, HNO3) solution of a certain concentration (for example, a concentration of 25% by volume) to the positive electrode material to dissolve the positive electrode material, and dilute with a certain volume (for example, 475 mL) of deionized water, then put the diluted liquid into an inductively coupled plasma optical emission spectrometer (for example, ICAP7400 of Thermo Fisher Scientific, USA) for target element analysis, and calculate the chemical formula of the positive electrode material.

[0159] The prepared lithium ion battery was subjected to the following tests:

[0160] 1. Initial specific capacity test and 25°C cycle performance test of lithium ion battery

[0161] At 25°C, the lithium ion battery was charged at 0.5C constant current to a voltage of 4.45V, then charged at 4.45V constant voltage until the current was less than or equal to 0.05mA, and then discharged at 0.5C constant current to a voltage of 2.5V, which was one charge and discharge process. The discharge capacity at this time was recorded as the discharge capacity of the first cycle of the battery. The charging and discharging cycles were repeated in this way, and the number of cycles corresponding to a capacity retention rate of 80% was calculated.

[0162] The capacity retention rate (%) of the battery after 25°C cycling N times = (the discharge capacity of the battery in the Nth cycle / the discharge capacity of the battery in the first cycle) x 100%.

[0163] 2. Storage performance test of lithium ion battery at 60°C

[0164] In a constant temperature environment at 25°C, the battery was charged at 0.33C to 4.45V, and then discharged at 0.33C to 2.5V, and the discharge capacity D1 was tested as the first discharge capacity. Then the battery was charged at 0.33C to 4.45V and constant voltage to a current less than or equal to 0.05mA, and then placed in a high and low temperature box at 60°C, and stored for 1h after the battery temperature reached the target temperature. Every 30 days, take out and test, cool the battery to 25°C each time, first charge the battery at 0.33C to 4.45V, then discharge at 0.33C to 2.5V, test the discharge capacity, until the storage time is equal to 60, and record the capacity retention rate at this time.

[0165] The capacity retention rate (%) of the battery after 60D storage at 60°C = (the discharge capacity of the battery after 60D storage / the discharge capacity of the battery after the first storage) x 100%.

[0166] Examples 2-5

[0167] Preparation and testing were carried out in the same way as Example 1 except that W1 was different, and the relevant parameters and test results are shown in Table 1.

[0168] Comparative Example 1

[0169] Preparation and testing were carried out in the same way as Example 1 except for the following differences, and some of the relevant parameters and test results are shown in Table 1.

[0170] The lithium-rich manganese-based oxide as the positive electrode active material was 0.12Li2MnO3·0.88LiNi 0.4 Co 0.1 Mn 0.5 O2, with a specific surface area of 2.1 m 2 / g and a micro stress of 0.65%; the mass ratio W1 of the metal oxide CeO2 in the positive electrode material layer was 15%.

[0171] Comparative Example 2

[0172] Preparation and testing were carried out in the same way as Example 1 except that the mass ratio W1 of the metal oxide CeO2 in the positive electrode material layer was 0.0005%, and the relevant parameters and test results are shown in Table 1.

[0173] Comparative Example 3

[0174] Preparation and testing were carried out in the same way as Example 1 except that no metal oxide was added, and the relevant parameters and test results are shown in Table 1.

[0175] Table 1

[0176] As can be seen from the results in Table 1, the use of a metal oxide as a positive electrode additive in a lithium-rich manganese-based oxide battery system can significantly improve the cycle performance and high-temperature storage performance of the battery, and also has certain benefits for the battery gram capacity.

[0177] As can be seen from a comparison of Examples 1-5, when the amount of metal oxide added is within an appropriate range (0.001%≤W1≤10%), it has a certain effect on improving the battery gram capacity. Furthermore, by optimizing the amount of metal oxide added, it is beneficial to further improve the cycle performance and high-temperature storage performance of the battery.

[0178] Examples 6-9

[0179] On the basis of Example 1, the specific material of the lithium-rich manganese-based oxide and its specific surface area, micro stress, the content of the metal oxide W1 were changed, and tests were performed. The differences of Examples 6-9 relative to Example 1, and the test results are shown in Table 2.

[0180] Table 2

[0181] Examples 10-12

[0182] In addition to the Dv50 of the metal oxide, preparation and testing were performed in the same manner as Example 1, and the relevant parameters and test results are shown in Table 3.

[0183] Table 3

[0184] Examples 13-15

[0185] In addition to the specific components of the metal oxide, preparation and testing were performed in the same manner as Example 1, and the relevant parameters and test results are shown in Table 4.

[0186] Table 4

[0187] Examples 16-18

[0188] In addition to the specific surface area of the negative electrode active material, preparation and testing were performed in the same manner as Example 1, and the relevant parameters and test results are shown in Table 5.

[0189] Table 5

[0190] The above description is merely preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery cell, characterized by, The battery device comprises the battery cell according to any one of claims 1-9. The electric device comprises the battery cell according to any one of claims 1-9 or the battery device according to claim 10.

2. The battery cell of claim 1, wherein, 0.025％≤W1≤5％。 3. The battery cell according to claim 1 or 2, wherein ​ 4. The battery cell according to claim 1 or 2, wherein ​ 5. The battery cell according to any one of claims 1 to 4, wherein The molecular formula of the lithium-rich manganese-based oxide material is xLi2MnO3·(1-x)LiNi y Co z Mn a M 1-y-z-a O r A 2-r , wherein 0 < x < 1, 0≤y≤1, 0≤z≤1, 0≤a≤1, 0 < r < 2, 0 < y + z + a < 1; M is at least one of Mg, B, Al, V, Ti, Zr, Sn and Mo, and A is at least one of F, S, N and Cl.

6. The battery cell of claim 5, wherein, ​ 7. The battery cell according to any one of claims 1 to 6, wherein The lithium-rich manganese-based oxide material has a specific surface area of 0.7 m 2 / g to 2.8 m 2 / g.

8. The battery cell according to any one of claims 1 to 7, wherein ​ 9. The battery cell according to any one of claims 1 to 8, wherein The negative electrode sheet includes a negative electrode active material, the specific surface area of the negative electrode active material being 0.5 m 2 / g ~ 2.0 m 2 / g.

10. A battery device characterized by comprising: ​ 11. An electrical device, characterized by ​

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