Lithium-rich manganese-based positive electrode material and preparation method thereof, positive electrode plate, lithium ion battery and electric device

Abstract

The invention relates to a lithium-rich manganese-based positive electrode material, a positive electrode plate, a lithium ion battery and an electric device. The lithium-rich manganese-based positive electrode material has a particle size span SPAN of 1.6-2.0, a volume distribution particle size Dv50 of 6.5 [mu] m-10.19 [mu] m, a compact density CPD of 2.9 g / cm < 3 >-3.3 g / cm < 3 > and a specific surface area BET of 1.5 m < 2 > / g-3. 5m < 2 > / g. According to the present invention, the particle size span SPAN, the volume distribution particle size Dv50, the compaction density CPD and the specific surface area BET of the lithium-rich manganese-based positive electrode material are respectively controlled in the above ranges, such that the positive electrode plate can easily obtain the high compaction density under the high loading capacity, and the positive electrode plate has characteristics of low elongation rate and excellent processing performance.

Description

Technical Field

[0001] This application relates to the field of lithium-ion battery technology, and in particular to a lithium-rich manganese-based cathode material and its preparation method, cathode sheet, lithium-ion battery, and power device. Background Technology

[0002] In recent years, lithium-ion batteries have been widely used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, as well as in power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, and many other fields due to their outstanding characteristics such as light weight, no pollution, and no memory effect. With the rapid expansion of the lithium-ion battery market, high energy density has become a focus of close attention, which in turn places higher demands on the compaction density of the positive electrode sheet.

[0003] Lithium-rich manganese-based active materials possess high specific capacity and energy density, and are considered one of the most promising next-generation high-performance cathode materials. However, cathode sheets using lithium-rich manganese-based active materials have low compaction density, which cannot meet the requirements for high compaction density in cathode sheets. Summary of the Invention

[0004] This application provides a lithium-rich manganese-based cathode material and its preparation method, a cathode sheet, a lithium-ion battery, and an electrical device, to improve the compaction density of the cathode sheet and enhance the cycle performance of the lithium-ion battery.

[0005] To achieve the above objectives, the first aspect of this application provides a lithium-rich manganese-based cathode material, wherein the particle size distribution span (SPAN) of the lithium-rich manganese-based cathode material is 1.6-2.0, the volume distribution particle size (Dv50) is 6.5 μm-10.1 μm, and the compaction density (CPD) is 2.9 g / cm³. 3 -3.3g / cm 3 The specific surface area (BET) is 1.5 m². 2 / g -3.5m 2 / g.

[0006] Therefore, by controlling the volume distribution particle size Dv50 of the lithium-rich manganese-based cathode material within the aforementioned range, this application helps to avoid particle cracking due to excessively large particles, which would affect performance, while also preventing particles that are too small from failing to provide a proper framework. By controlling the particle size span SPAN of the lithium-rich manganese-based cathode material within the aforementioned range, it helps to achieve higher compaction density under high loading conditions. By controlling the compaction density CPD of the lithium-rich manganese-based cathode material within the aforementioned range, it helps to increase the powder density of the material and improve the compressive strength of the electrode. By controlling the specific surface area BET of the lithium-rich manganese-based cathode material within the aforementioned range, it helps to avoid excessive surface energy due to an excessively large specific surface area, which would affect processing performance. Therefore, by controlling the particle size span SPAN, volume distribution particle size Dv50, compaction density CPD, and specific surface area BET of the lithium-rich manganese-based cathode material within the aforementioned ranges, it is beneficial for the cathode to achieve higher compaction density under high loading conditions, while maintaining low elongation and exhibiting excellent processing performance.

[0007] In some embodiments of this application, the lithium-rich manganese-based cathode material includes a first active material and a second active material, wherein the first active material and the second active material have different volume distribution particle sizes. Therefore, using a mixture of two active materials with different volume distribution particle sizes can significantly improve the porosity and volume utilization between particles, thereby enhancing the compressive strength and ductility of the mixed cathode material.

[0008] In some embodiments of this application, the volume distribution particle size Dv50 of the first active material is 6 μm-10 μm, and the volume distribution particle size Dv50 of the second active material is 1.5 μm-3.5 μm. Therefore, when the first and second active materials are used together, the first active material acts as a framework, and the second active material acts as a filler, improving space utilization.

[0009] In some embodiments of this application, the first active material is a polycrystalline lithium-rich manganese-based cathode material, and the second active material is one or more of a monocrystalline lithium-rich manganese-based cathode material, a polycrystalline lithium-rich manganese-based cathode material, and a lithium-nickel composite oxide.

[0010] In some embodiments of this application, the first active material is a polycrystalline lithium-rich manganese-based cathode material, and the second active material is a monocrystalline lithium-rich manganese-based cathode material. Thus, when the first active material is a polycrystalline particle, it can act as a large particle framework, and when the second active material is a monocrystalline particle, it can act as a small particle filler, thereby improving the overall particle density of the mixed powder.

[0011] In some embodiments of this application, the mass ratio of the first active material to the second active material is (1.5-9):1. This is beneficial for maximizing the specific capacity of the material while also ensuring the electrode compaction density and resistance to electrode breakage due to particle slippage / displacement.

[0012] In some embodiments of this application, the volume distribution particle size Dv10 of the first active material is 0.5 μm-2.5 μm.

[0013] In some embodiments of this application, the volume distribution particle size Dv99 of the first active material is 7μm-20μm.

[0014] When the volume distribution particle size Dv10 and volume distribution particle size Dv99 of the first active material are within the above ranges, it is beneficial for the first active material to simultaneously play a framework and filling role.

[0015] In some embodiments of this application, the volume distribution particle size Dv10 of the second active material is 0.5 μm-2.5 μm.

[0016] In some embodiments of this application, the volume distribution particle size Dv99 of the second active material is 1μm-7.5μm.

[0017] When the volume distribution particle size Dv10 and volume distribution particle size Dv99 of the second active material are within the above ranges, it is even more beneficial for the second active material to play a filling role.

[0018] In some embodiments of this application, the particle size span (SPAN) of the first active material is 0.5-1.2. This is beneficial for providing sufficient filling space and maximizing the specific capacity of the positive electrode sheet.

[0019] In some embodiments of this application, the particle size span (SPAN) of the first active material is 0.8-1.1.

[0020] In some embodiments of this application, the particle size span (SPAN) of the second active material is 1.0-1.8, thereby better filling the pores and spaces left by the first active material and improving the compaction density.

[0021] In some embodiments of this application, the particle size span (SPAN) of the second active material is 1.2-1.6.

[0022] In some embodiments of this application, the specific surface area (BET) of the first active material is 1.3 m². 2 / g -1.7m 2 / g.

[0023] In some embodiments of this application, the specific surface area (BET) of the second active material is 1.5 m². 2 / g -2.1m 2 / g.

[0024] When the specific surface areas (BET) of the first and second active materials are within the above-mentioned ranges, the lithium-rich manganese-based cathode material can be guaranteed to have better electrochemical stability.

[0025] In some embodiments of this application, the compaction density (PD) of the first active material is 2.7 g / cm³. 3 -3.1g / cm 3 .

[0026] In some embodiments of this application, the compaction density (PD) of the second active material is 2.5 g / cm³. 3 -2.8g / cm 3 .

[0027] When the compaction densities (PD) of the first and second active materials are within the above-mentioned ranges, it is beneficial to improve the compaction density of the electrode sheet using lithium-rich manganese-based cathode material.

[0028] In some embodiments of this application, the true density of the first active material is 4.2 g / cm³. 3 -4.45g / cm 3 .

[0029] In some embodiments of this application, the true density of the second active material is 4.1 g / cm³. 3 -4.35g / cm 3 .

[0030] When the true densities of the first and second active materials are within the aforementioned ranges, it is beneficial to increase the compaction density of the electrode sheet using lithium-rich manganese-based cathode material.

[0031] In some embodiments of this application, the tap density TD of the first active material is ≥1.8 g / cm³. 3 This helps improve the overall dispersion of lithium-rich manganese-based cathode materials, thereby increasing the compaction density and ductility of the cathode sheet.

[0032] In some embodiments of this application, the tap density (TD) of the first active material is 1.8 g / cm³. 3 -2.35g / cm 3 .

[0033] In some embodiments of this application, the tap density (TD) of the first active material is 2.0 g / cm³. 3 -2.35g / cm 3.

[0034] In some embodiments of this application, the tap density TD of the second active material is ≥1.8 g / cm³. 3 This helps improve the overall dispersion of lithium-rich manganese-based cathode materials, thereby increasing the compaction density and ductility of the cathode sheet.

[0035] In some embodiments of this application, the tap density (TD) of the second active material is 1.8 g / cm³. 3 -2.35g / cm 3 .

[0036] In some embodiments of this application, the tap density (TD) of the second active material is 2.0 g / cm³. 3 -2.35g / cm 3 .

[0037] In some embodiments of this application, the chemical formula of the first active material is Li[Li x Ni a Co b Mn c M d O 2-e Z e , where x+a+b+c+d=1, x>0, a+b+c+d<1, 0<b≤0.1, 0≤e≤0.2, element M includes one or more of Te, Se, Mg, Nb, Cr, Ce, Fe, Ta, B, V, Ti, Sn, W and Mo, and element Z includes one or more of F, Cl and Br.

[0038] In some embodiments of this application, a > 0.1, c ≥ 0.5, and d ≥ 0.

[0039] In some embodiments of this application, the chemical formula of the second active material is Li[Li x1 Ni a1 Co b1 Mn c1 M1 d1 O 2-e1 Z1 e1 Where x1+a1+b1+c1+d1=1, x1>0, a1+b1+c1+d1<1, 0<b1≤0.1, 0≤e≤0.2, M1 element includes one or more of Te, Se, Mg, Nb, Cr, Ce, Fe, Ta, B, V, Ti, Sn, W and Mo, and Z1 element includes one or more of F, Cl and Br.

[0040] In some embodiments of this application, a1 > 0.1, c1 ≥ 0.5, and d1 ≥ 0.

[0041] In some embodiments of this application, the lithium-nickel composite oxide is a lithium-containing nickel-cobalt-manganese metal oxide.

[0042] In some embodiments of this application, the lithium-nickel composite oxide further comprises one or more of cobalt, manganese and aluminum, and the molar percentage of nickel in all metal elements other than lithium is ≥80%.

[0043] A second aspect of this application provides a method for preparing a lithium-rich manganese-based cathode material, comprising the following steps:

[0044] The lithium-rich manganese-based cathode material is prepared by mixing a first active material and a second active material; wherein the first active material and the second active material have different volume distribution particle sizes.

[0045] The lithium-rich manganese-based cathode material has a particle size span (SPAN) of 1.6-2.0, a volume distribution particle size (Dv50) of 6.5 μm-10.1 μm, and a compaction density (CPD) of 2.9 g / cm³. 3 -3.3g / cm 3 The specific surface area (BET) is 1.5 m². 2 / g -3.5m 2 / g.

[0046] A third aspect of this application provides a positive electrode sheet comprising the lithium-rich manganese-based positive electrode material of the first aspect of this application.

[0047] The positive electrode sheet of this application includes the lithium-rich manganese-based positive electrode material provided in this application, which has a high compaction density and a low elongation.

[0048] In some embodiments of this application, the compaction density of the positive electrode sheet is ≥2.86 g / cm³. 3 .

[0049] In some embodiments of this application, the compaction density of the positive electrode sheet is 2.86 g / cm³. 3 -3.1g / cm 3 .

[0050] In some embodiments of this application, the elongation of the positive electrode sheet is ≤0.7%.

[0051] In some embodiments of this application, the elongation of the positive electrode sheet is 0.43%-0.7%.

[0052] The fourth aspect of this application provides a lithium-ion battery, including the positive electrode sheet of the third aspect of this application.

[0053] The lithium-ion battery of this application includes the lithium-rich manganese-based cathode material provided in this application, which has high energy density and capacity, as well as excellent cycle performance.

[0054] The fifth aspect of this application provides an electrical device, including at least one of the positive electrode sheet of the third aspect of this application and the lithium-ion battery of the fourth aspect of this application.

[0055] The electrical device of this application includes the lithium-ion battery provided in this application, and therefore has at least the same advantages as the lithium-ion battery.

[0056] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0057] To better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments or examples, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0058] Figure 1 This is a schematic diagram of a battery cell according to one embodiment of this application.

[0059] Figure 2 for Figure 1 An exploded view of a battery cell according to one embodiment of this application is shown.

[0060] Figure 3 This is a schematic diagram of a battery module according to one embodiment of this application.

[0061] Figure 4 This is a schematic diagram of a battery pack according to one embodiment of this application.

[0062] Figure 5 for Figure 4 An exploded view of a battery pack according to one embodiment of this application is shown.

[0063] Figure 6 This is a schematic diagram of an electrical device that uses a lithium-ion battery as a power source according to one embodiment of this application.

[0064] Explanation of reference numerals in the attached figures:

[0065] 1 Battery pack; 2 Upper housing; 3 Lower housing; 4 Battery module; 5 Battery cell; 51 Housing; 52 Electrode assembly; 53 Cover plate; 6 Electrical device. Detailed Implementation

[0066] The following describes in detail some embodiments of the lithium-rich manganese-based cathode material, cathode sheet, secondary battery, and power application device of this application, with appropriate reference to the accompanying drawings. However, some unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0067] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be combined arbitrarily, meaning 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 for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0" and "5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when describing a parameter as an integer ≥ 2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 for that parameter. For instance, when describing a parameter as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0068] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0069] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0070] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The term "implementation" as used herein has a similar understanding.

[0071] Those skilled in the art will understand that the order in which the steps are written in the methods of various embodiments or examples does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0072] In this application, open-ended technical features or solutions described using terms such as "containing," "comprising," or "including" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, if A includes a1, a2, and a3, it may also include other members or exclude additional members unless otherwise specified. This can be considered as providing both the feature or solution that "A consists of a1, a2, and a3" and the feature or solution that "A includes not only a1, a2, and a3, but also other members." In this application, unless otherwise specified, A (e.g., B) indicates that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0073] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0074] Lithium-rich manganese-based active materials possess high specific capacity and energy density, and are considered one of the most promising next-generation high-performance cathode materials. However, the true density and sphericity of lithium-rich manganese-based active materials are somewhat inferior to those of conventional ternary cathode materials, making it difficult to improve the compaction density of cathode sheets during actual processing. The inventors discovered that the common method to improve electrode compaction density is to mix large and small particles, increasing the difference in the volume average particle size (Dv50) between large and small particles, thereby achieving better particle mixing. However, since the particles in the electrode are a mixture of large and small particles, not just individual particle properties of large and small particles, limiting only the volume average particle size (Dv50) of large and small particles has limited effect on improving the electrode compaction density. Therefore, to improve the electrode compaction density, it is necessary to consider the relevant parameters of the mixed powder.

[0075] Based on the above problems, this application regulates the particle size span (SPAN), volume distribution particle size (Dv50), compaction density (CPD), and specific surface area (BET) of lithium-rich manganese-based cathode materials to improve the compaction density of the cathode sheet.

[0076] One or more embodiments of this application provide a lithium-rich manganese-based cathode material, wherein the particle size distribution span (SPAN) of the lithium-rich manganese-based cathode material is 1.6-2.0, the volume distribution particle size (Dv50) is 6.5μm-10.1μm, and the compaction density (CPD) is 2.9 g / cm³. 3 -3.3g / cm 3 The specific surface area (BET) is 1.5 m². 2 / g -3.5m 2 / g.

[0077] Understandably, by controlling the volume distribution particle size Dv50 of the lithium-rich manganese-based cathode material within the aforementioned range, this application helps to avoid particle cracking due to excessively large particles, which would affect performance, while also preventing particles that are too small to function as the main framework. By controlling the particle size span SPAN of the lithium-rich manganese-based cathode material within the aforementioned range, it helps to achieve higher compaction density under high loading. By controlling the compaction density CPD of the lithium-rich manganese-based cathode material within the aforementioned range, it helps to increase the powder density of the material and improve the compressive strength of the electrode. By controlling the specific surface area BET of the lithium-rich manganese-based cathode material within the aforementioned range, it helps to avoid excessive surface energy due to excessive specific surface area, which would affect processing performance. Therefore, by controlling the particle size span SPAN, volume distribution particle size Dv50, compaction density CPD, and specific surface area BET of the lithium-rich manganese-based cathode material within the aforementioned ranges, this application helps to achieve higher compaction density of the cathode sheet under high loading, while the cathode sheet has low elongation and excellent processing performance.

[0078] As a non-limiting example, the particle size span (SPAN) of the lithium-rich manganese-based cathode material can be, but is not limited to, 1.6, 1.61, 1.62, 1.63, 1.64, 1.65, 1.67, 1.7, 1.73, 1.75, 1.78, 1.8, 1.83, 1.85, 1.88, 1.9, 1.93, 1.95, 1.97, 2.0, or any range between two of the above values.

[0079] It should be noted that the particle size span (SPAN) mentioned above is calculated as (Dv90 - Dv10) / Dv50. Here, Dv10 refers to the particle size corresponding to 10% of the volumetric distribution, Dv50 refers to the particle size corresponding to 50% of the volumetric distribution, and Dv90 refers to the particle size corresponding to 50% of the volumetric distribution. Refer to GB / T 19077-2016 / ISO 13320:2009 Particle Size Distribution Laser Diffraction Method, and use a laser particle size analyzer to measure Dv10, Dv50, and Dv90 respectively, then calculate the SPAN using the formula (Dv90 - Dv10) / Dv50.

[0080] As an example, the volumetric particle size Dv50 of lithium-rich manganese-based cathode materials can be, but is not limited to, 6.5 μm, 6.6 μm, 6.7 μm, 6.8 μm, 6.9 μm, 7 μm, 7.1 μm, 7.2 μm, 7.3 μm, 7.4 μm, 7.5 μm, 7.6 μm, 7.7 μm, 7.8 μm, 7.9 μm, 8 μm, 8.1 μm, 8.2 μm, 8.3 μm, 8.4 μm, 8.5 μm, 8.6 μm, 8.7 μm, 8.8 μm, 8.9 μm, 9 μm, 9.1 μm, 9.2 μm, 9.3 μm, 9.4 μm, 9.5 μm, 9.6 μm, 9.7 μm, 9.8 μm, 9.9 μm, 10 μm, 10.1 μm, or any range between any two of the above values.

[0081] It should be noted that the volumetric particle size Dv50 mentioned above refers to the particle size corresponding to 50% of the volumetric distribution; it can be determined by referring to GB / T 19077-2016 / ISO 13320:2009 Particle size distribution by laser diffraction.

[0082] As a non-limiting example, the compaction density (CPD) of lithium-rich manganese-based cathode materials can be, but is not limited to, 2.9 g / cm³. 3 2.93g / cm 3 2.95g / cm 3 2.98g / cm 3 3.0g / cm 3 3.03 g / cm 3 3.05g / cm 33.08g / cm 3 3.1g / cm 3 3.13 g / cm 3 3.15g / cm 3 3.18 g / cm 3 3.2g / cm 3 3.23 g / cm 3 3.25g / cm 3 3.28g / cm 3 3.3g / cm 3 Or the range between any two of the above compaction densities, etc.

[0083] It should be noted that the compaction density (CPD) of the lithium-rich manganese-based cathode material mentioned above refers to the compaction density (CPD-5T) of the lithium-rich manganese-based cathode material under a pressure of 5 tons. As an example, refer to GB / T 5162-2006 "Graphite Anode Materials for Lithium-ion Batteries", which is measured using a UTM7305 electronic pressure testing machine.

[0084] As a non-limiting example, the specific surface area BET of lithium-rich manganese-based cathode materials can be, but is not limited to, 1.5 m². 2 / g, 1.6m 2 / g, 1.7m 2 / g, 1.8m 2 / g, 1.9m 2 / g, 2.0m 2 / g、2.1m 2 / g, 2.2m 2 / g, 2.3m 2 / g, 2.4m 2 / g, 2.5m 2 / g, 2.6m 2 / g, 2.7m 2 / g, 2.8m 2 / g, 2.9m 2 / g, 3.0m 2 / g, 3.1m 2 / g, 3.2m 2 / g, 3.3m 2 / g, 3.4m 2 / g, 3.5m 2 / g or the range between any two of the above specific surface areas, etc.

[0085] It should be noted that the specific surface area (BET) of the lithium-rich manganese-based cathode material mentioned above can be determined by referring to the gas adsorption BET method in GB / T19587-2004.

[0086] In some embodiments, the lithium-rich manganese-based cathode material includes a first active material and a second active material, the first and second active materials having different volume distribution particle sizes. Therefore, using a mixture of two active materials with different volume distribution particle sizes can significantly improve the porosity and volume utilization between particles, thereby enhancing the compressive strength and ductility of the mixed cathode material.

[0087] The terms "first active material," "second active material," etc., mentioned above are for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed-ended limitation on quantity.

[0088] In some optional embodiments, the volume distribution particle size Dv50 of the first active material is 6μm-10μm; for example, it can be, but is not limited to, 6μm, 6.3μm, 6.5μm, 6.8μm, 7μm, 7.3μm, 7.5μm, 7.8μm, 8μm, 8.3μm, 8.5μm, 8.7μm, 9μm, 9.3μm, 9.5μm, 9.7μm, 10μm, or any range between two of the above values. When the volume distribution particle size Dv50 of the first active material is within the above range, it is beneficial to maximize the material's capacity while also preventing the material particles from breaking.

[0089] As one possible implementation, the volume distribution particle size Dv50 of the second active material is 1.5μm-3.5μm; for example, it can be, but is not limited to, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, or any range between two of the above values.

[0090] When a first active material and a second active material with a volume distribution particle size Dv50 within the above-mentioned range are used together, the first active material can act as a framework and the second active material can act as a filler, thereby improving space utilization.

[0091] It should be noted that the volume distribution particle size Dv50 of the first and second active materials mentioned above can be determined by referring to GB / T 19077-2016 / ISO 13320:2009 Particle size distribution laser diffraction method.

[0092] In some embodiments, the first active material is a polycrystalline lithium-rich manganese-based cathode material, and the second active material is one or more of a monocrystalline lithium-rich manganese-based cathode material, a polycrystalline lithium-rich manganese-based cathode material, and a lithium-nickel composite oxide.

[0093] In some embodiments, the first active material is a polycrystalline lithium-rich manganese-based cathode material, and the second active material is a monocrystalline lithium-rich manganese-based cathode material. Thus, when the first active material is a polycrystalline particle, it can act as a large particle framework, and when the second active material is a monocrystalline particle, it can act as a small particle filler, thereby improving the overall particle density of the mixed powder.

[0094] As one possible implementation, the mass ratio of the first active material to the second active material is (1.5-9):1; for example, it can be, but is not limited to, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, or any range between two of the above mass ratios. When the mass ratio of the first active material to the second active material is within the above range, it is beneficial to maximize the material's specific capacity while also ensuring the electrode compaction density and resistance to electrode breakage due to particle slippage / displacement.

[0095] In some optional embodiments, the volume distribution particle size Dv10 of the first active material is 0.5 μm to 2.5 μm; for example, it can be, but is not limited to, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2.0 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, 2.5 μm, or any range between two of the above values.

[0096] As one possible implementation, the volume distribution particle size Dv99 of the first active material is 7μm-20μm; for example, it can be, but is not limited to, 7μm, 7.5μm, 8μm, 8.5μm, 9μm, 9.5μm, 10μm, 10.5μm, 11μm, 11.5μm, 12μm, 12.5μm, 13μm, 13.5μm, 14μm, 14.5μm, 15μm, 15.5μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, or any range between two of the above values.

[0097] When the volume distribution particle size Dv10 and volume distribution particle size Dv99 of the first active material are within the above ranges, it is beneficial for the first active material to simultaneously play a framework and filling role.

[0098] In some optional embodiments, the volume distribution particle size Dv10 of the second active material is 0.5 μm to 2.5 μm; for example, it can be, but is not limited to, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2.0 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, 2.5 μm, or any range between two of the above values.

[0099] In some embodiments, the volume distribution particle size Dv99 of the second active material is 1μm-7.5μm; for example, it can be, but is not limited to, 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, or any range between any two of the above values.

[0100] When the volume distribution particle size Dv10 and volume distribution particle size Dv99 of the second active material are within the above ranges, it is even more beneficial for the second active material to play a filling role.

[0101] In some exemplary embodiments, the particle size span (SPAN) of the first active material is 0.5-1.2; for example, it can be, but is not limited to, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, or any range between two of the above values. When the particle size span (SPAN) of the first active material is within the above range, it is beneficial to provide sufficient filling space and specific capacity for the positive electrode sheet.

[0102] In some alternative embodiments, the particle size span (SPAN) of the first active material is 0.8-1.1.

[0103] As one possible implementation, the particle size span (SPAN) of the second active material is 1.0-1.8; for example, it can be, but is not limited to, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, or any range between two of the above values. When the particle size span (SPAN) of the second active material is within the above range, it can better fill the pores and spaces left by the first active material, thereby increasing the compaction density.

[0104] In some alternative embodiments, the particle size span (SPAN) of the second active material is 1.2-1.6.

[0105] In some embodiments, the tap density TD of the first active material is ≥1.8 g / cm³. 3 When the tap density of the first active material is within the above range, it is beneficial to improve the overall dispersion of the lithium-rich manganese-based cathode material, thereby improving the compaction density and ductility of the cathode sheet.

[0106] In some embodiments, the specific surface area (BET) of the first active material is 1.3 m². 2 / g -1.7m 2 / g; for example, it can be, but is not limited to, 1.3m. 2 / g, 1.35m 2 / g, 1.4m 2 / g, 1.45m 2 / g, 1.5m 2 / g, 1.55m 2 / g, 1.6m 2 / g, 1.65m 2 / g, 1.7m 2 / g or the range between any two of the above specific surface areas, etc.

[0107] In some embodiments, the specific surface area (BET) of the second active material is 1.5 m². 2 / g -2.1m 2 / g; for example, it can be, but is not limited to, 1.5m. 2 / g, 1.6m 2 / g, 1.7m 2 / g, 1.8m 2 / g, 1.9m 2 / g, 2.0m 2 / g、2.1m 2 / g or the range between any two of the above specific surface areas, etc.

[0108] When the specific surface areas of the first and second active materials are within the above-mentioned ranges, the lithium-rich manganese-based cathode material can be guaranteed to have better electrochemical stability.

[0109] In some embodiments, the compaction density (PD) of the first active material is 2.7 g / cm³. 3 -3.1g / cm 3 For example, it can be, but is not limited to, 2.7 g / cm³. 3 2.75g / cm 3 2.8g / cm 3 2.85g / cm 3 2.9g / cm 3 2.95g / cm 3 3.0g / cm 3 3.05g / cm 3 3.1g / cm 3 Or the range between any two of the above compaction densities, etc.

[0110] In some embodiments, the compaction density (PD) of the second active material is 2.5 g / cm³. 3 -2.8g / cm 3 For example, it can be, but is not limited to, 2.5 g / cm³. 3 2.55g / cm 3 2.6g / cm 3 2.65g / cm 3 2.7g / cm 3 2.75g / cm 3 2.8g / cm 3 Or the range between any two of the above compaction densities, etc.

[0111] When the compaction densities (PD) of the first and second active materials are within the above-mentioned ranges, it is beneficial to improve the compaction density of the electrode sheet using lithium-rich manganese-based cathode material.

[0112] In some embodiments, the true density of the first active material is 4.2 g / cm³. 3 -4.45g / cm 3 For example, it can be, but is not limited to, 4.2 g / cm³. 3 4.25g / cm 3 4.3g / cm 3 4.35g / cm 3 4.4 g / cm 3 4.45g / cm 3 Or the range between any two true densities mentioned above, etc.

[0113] In some embodiments, the true density of the second active material is 4.1 g / cm³. 3 -4.35g / cm 3 For example, it can be, but is not limited to, 4.1 g / cm³. 3 4.15g / cm 3 4.2g / cm 3 4.25g / cm 3 4.3g / cm 3 4.35g / cm 3 Or the range between any two true densities mentioned above, etc.

[0114] When the true densities of the first and second active materials are within the aforementioned ranges, it is beneficial to increase the compaction density of the electrode sheet using lithium-rich manganese-based cathode material.

[0115] In some alternative embodiments, the tap density TD of the first active material is 1.8 g / cm³. 3 -2.35g / cm 3 For example, it can be, but is not limited to, 1.8 g / cm³. 3 1.82g / cm 3 1.85g / cm 3 1.87 g / cm 3 1.9g / cm 3 1.93g / cm 3 1.95g / cm 3 1.98g / cm 3 2.0g / cm 3 2.03 g / cm 3 2.05g / cm 3 2.07 g / cm 3 2.1g / cm 3 2.13 g / cm 3 2.15g / cm 3 2.17 g / cm 3 2.2g / cm 3 2.23 g / cm 3 2.25g / cm 3 2.27 g / cm 3 2.3g / cm 3 2.33 g / cm 3 2.35g / cm 3 Or the range between any two tap densities mentioned above, etc.

[0116] As one possible implementation, the tap density (TD) of the first active material is 2.0 g / cm³. 3 -2.35g / cm3 .

[0117] In some embodiments, the tap density TD of the second active material is ≥1.8 g / cm³. 3 When the tap density of the second active material is within the above range, it is beneficial to improve the overall dispersion of the lithium-rich manganese-based cathode material, thereby improving the compaction density and ductility of the cathode sheet.

[0118] In some alternative embodiments, the tap density (TD) of the second active material is 1.8 g / cm³. 3 -2.35g / cm 3 For example, it can be, but is not limited to, 1.8 g / cm³. 3 1.82g / cm 3 1.85g / cm 3 1.87 g / cm 3 1.9g / cm 3 1.93g / cm 3 1.95g / cm 3 1.98g / cm 3 2.0g / cm 3 2.03 g / cm 3 2.05g / cm 3 2.07 g / cm 3 2.1g / cm 3 2.13 g / cm 3 2.15g / cm 3 2.17 g / cm 3 2.2g / cm 3 2.23 g / cm 3 2.25g / cm 3 2.27 g / cm 3 2.3g / cm 3 2.33 g / cm 3 2.35g / cm 3 Or the range between any two tap densities mentioned above, etc.

[0119] As one possible implementation, the tap density (TD) of the second active material is 2.0 g / cm³. 3 -2.35g / cm 3 .

[0120] As one possible implementation method, the chemical formula of the first active material is Li[Li x Ni a Co b Mn c M d O 2-e Ze , where x+a+b+c+d=1, x>0, a+b+c+d<1, 0<b≤0.1, 0≤e≤0.2, element M includes one or more of Te, Se, Mg, Nb, Cr, Ce, Fe, Ta, B, V, Ti, Sn, W and Mo, and element Z includes one or more of F, Cl and Br.

[0121] In some alternative implementations, a > 0.1, c ≥ 0.5, and d ≥ 0.

[0122] In some exemplary embodiments, the chemical formula of the second active material is Li[Li] x1 Ni a1 Co b1 Mn c1 M1 d1 O 2-e1 Z1 e1 Where x1+a1+b1+c1+d1=1, x1>0, a1+b1+c1+d1<1, 0<b1≤0.1, 0≤e≤0.2, M1 element includes one or more of Te, Se, Mg, Nb, Cr, Ce, Fe, Ta, B, V, Ti, Sn, W and Mo, and Z1 element includes one or more of F, Cl and Br.

[0123] It should be noted that when x1=0, the second active material is a ternary cathode material.

[0124] In some alternative implementations, a1 > 0.1, c1 ≥ 0.5, and d1 ≥ 0.

[0125] In some exemplary embodiments, the lithium-nickel composite oxide is a lithium-containing nickel-cobalt-manganese metal oxide.

[0126] In some embodiments, the lithium-nickel composite oxide further comprises one or more of cobalt, manganese and aluminum, wherein the molar percentage of nickel in all metal elements other than lithium is ≥80%.

[0127] One or more embodiments of this application provide a method for preparing a lithium-rich manganese-based cathode material, which can be used to prepare the aforementioned lithium-rich manganese-based cathode material. The preparation method includes the following steps:

[0128] A lithium-rich manganese-based cathode material was prepared by mixing a first active material and a second active material; wherein the first and second active materials have different volume distribution particle sizes; the particle size span (SPAN) of the lithium-rich manganese-based cathode material is 1.6-2.0, the volume distribution particle size (Dv50) is 6.5μm-10.1μm, and the compaction density (CPD) is 2.9 g / cm³. 3 -3.3g / cm3 The specific surface area (BET) is 1.5 m². 2 / g -3.5m 2 / g.

[0129] In addition, the lithium-ion battery and power-consuming device of this application will be described below with appropriate reference to the accompanying drawings.

[0130] Typically, a lithium-ion battery consists of a positive electrode, a negative electrode, an electrolyte, and a separator. During charging and discharging, active ions move back and forth between the positive and negative electrodes, inserting and extracting. The electrolyte acts as a conductor between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, primarily prevents short circuits while allowing ions to pass through.

[0131] Positive electrode sheet

[0132] The positive electrode includes a positive current collector and a positive active material layer disposed on at least one surface of the positive current collector, the positive active material layer including the lithium-rich manganese-based positive electrode material described above in this application.

[0133] In one embodiment, the compaction density of the positive electrode sheet is ≥2.86 g / cm³. 3 .

[0134] In some alternative embodiments, the compaction density of the positive electrode sheet is 2.86 g / cm³. 3 -3.1g / cm 3 For example, it can be, but is not limited to, 2.86 g / cm³. 3 2.88g / cm 3 2.90g / cm 3 2.92g / cm 3 2.94 g / cm 3 2.96g / cm 3 2.98g / cm 3 3.0g / cm 3 3.02g / cm 3 3.04 g / cm 3 3.06 g / cm 3 3.08g / cm 3 3.1g / cm 3 Or the range between any two of the above compaction densities, etc.

[0135] It should be noted that the compaction density of the aforementioned positive electrode sheet can be calculated using the formula PD=M / (d×A). In the formula, M is the mass of the 40mm diameter small circular piece cut from the positive electrode sheet, which is the average value obtained by weighing 10 times; d is the thickness of the positive electrode sheet, which is the average value obtained by measuring the thickness 10 times; and A is the area of ​​the 40mm diameter small circular piece.

[0136] In some embodiments, the elongation of the positive electrode sheet is ≤0.7%.

[0137] In some alternative implementations, the elongation of the positive electrode sheet is 0.43%-0.7%; for example, it can be, but is not limited to, 0.43%, 0.45%, 0.48%, 0.5%, 0.53%, 0.55%, 0.58%, 0.6%, 0.63%, 0.65%, 0.68%, 0.7%, or any range between any two of the above elongation rates.

[0138] As an example, the elongation of the aforementioned positive electrode sheet can be calculated using the formula ΔEL%=(L2-L1) / L1×100%. In this formula, L1 is the distance between the marks before cold pressing, which is 1000mm, and L2 is the distance between the marks after cold pressing. The marks are formed as follows: In the central region of the electrode sheet, three line segments, each 1000mm long, are taken at different positions along the width direction of the electrode sheet, and the two endpoints of each line segment are marked. L2 is recorded as the average of the measured distances between the two endpoints of each line segment after cold pressing.

[0139] In some embodiments, the lithium-ion battery includes the positive electrode sheet described above.

[0140] As a non-limiting example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0141] In some embodiments, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymeric material substrate and a metal layer formed on at least one surface of the polymeric material substrate. The composite current collector can be obtained by forming a metal material on a polymeric material substrate. Non-limiting examples of the metal material in the positive electrode current collector may include one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limiting examples of the polymeric material substrate in the positive electrode current collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0142] In some embodiments, the positive electrode active material layer may further comprise one or more of ternary materials and lithium manganese iron phosphate materials; wherein, the ternary material includes Li h (Ni m Co n Mn j )1-fM f O2-yA y (h is 0.2-1.2) and / or Li h A m (Ni m Co n Mn j )1-fM f O2-yA y (h+m is 0.2-1.2); Lithium manganese iron phosphate materials include Li m Mn 1-y B y P 1-z C z O 4-n D n (m is 0-1.1) and / or Li m A h Mn 1-y B y P 1-z C z O 4-n D n (m+h is 0-1.1).

[0143] It should be noted that the above limitation on x includes the molar content of Li under different charge and discharge states of the battery (typically the battery voltage is between 2-5V).

[0144] Understandably, lithium (Li) is intercalated and deintercalated during the charging and discharging process of a battery, and the Li content in the positive electrode varies depending on the state of discharge. Unless otherwise specified, the Li content in the examples of positive electrode materials listed in this application refers to the initial state of the material. When a positive electrode material is applied to a positive electrode in a battery system, the Li content in the positive electrode material typically changes after charge-discharge cycles. The Li content can be measured using molar content, but is not limited to this. Regarding "Li content refers to the initial state of the material," the initial state of the material refers to its state before being added to the positive electrode slurry. It is understood that new materials obtained by appropriately modifying the listed positive electrode materials are also within the scope of positive electrode materials. The aforementioned appropriate modification refers to acceptable modification methods for the positive electrode material; non-limiting examples include coating modification.

[0145] In the examples of cathode materials in this application, the oxygen (O) content is only a theoretical value. Lattice oxygen release will cause changes in the molar content of oxygen, and the actual O content will fluctuate. The O content can be measured in molar content, but is not limited to this.

[0146] In some embodiments, the positive electrode active material may also be a known positive electrode active material for batteries. As a non-limiting example, the positive electrode active material may include one or more of the following materials: lithium-containing phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides include, but are not limited to, one or more of lithium cobalt oxides (such as LiCoO2), lithium nickel oxides, lithium manganese oxides, lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, and their modified compounds. Non-limiting examples of lithium-containing phosphates with an olivine structure include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium manganese iron phosphate and carbon composites. Non-limiting examples of lithium cobalt oxides may include LiCoO2; non-limiting examples of lithium nickel oxides may include LiNiO2; non-limiting examples of lithium manganese oxides may include LiMnO2, LiMn2O4, etc.; non-limiting examples of lithium nickel cobalt manganese oxides may include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 Examples of lithium nickel cobalt aluminum oxides include LiNi, etc. 0.80 Co 0.15 Al 0.05 O2.

[0147] In some embodiments, the positive electrode active material layer may optionally include a binder. As a non-limiting example, the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins.

[0148] In some embodiments, the positive electrode active material layer may optionally include a conductive agent. As a non-limiting example, the conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0149] In some embodiments, the positive electrode sheet can be prepared by dispersing the components used to prepare the positive electrode sheet, such as the positive active material, conductive agent, binder, and any other components, in a solvent to form a positive electrode slurry; coating the positive electrode slurry onto at least one surface of the positive electrode current collector, and then obtaining the positive electrode sheet after drying, cold pressing, and other processes. The solvent can be selected from, but is not limited to, any of the solvents described in the foregoing embodiments, such as N-methylpyrrolidone (NMP). The surface of the positive electrode current collector coated with the positive electrode slurry can be a single surface of the positive electrode current collector or both surfaces of the positive electrode current collector. The solid content of the positive electrode slurry can be 40wt%~80wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000 mPa·s - 25000 mPa·s. When coating the positive electrode slurry, the coating unit areal density (dry weight, minus solvent) can be 15 mg / cm³. 2 -35 mg / cm 2 The compaction density of the positive electrode sheet can be 3.0 g / cm³. 3 -3.6 g / cm 3 The option is 3.3 g / cm³. 3 -3.5 g / cm 3 .

[0150] Negative electrode sheet

[0151] The negative electrode sheet includes a negative current collector and a negative active material layer disposed on at least one surface of the negative current collector, wherein the negative active material layer includes a negative active material.

[0152] As a non-limiting example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0153] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymeric material substrate and a metal layer formed on at least one surface of the polymeric material substrate. The composite current collector can be obtained by forming a metal material on the polymeric material substrate. Non-limiting examples of the metal material in the negative electrode current collector may include one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limiting examples of the polymeric material substrate in the negative electrode current collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0154] In some embodiments, the negative electrode active material may be a negative electrode active material known in the art for use in batteries. As a non-limiting example, the negative electrode active material may include one or more of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may include one or more of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may include one or more of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0155] In some embodiments, the negative electrode active material layer may optionally include a binder. The binder may include one or more of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0156] In some embodiments, the negative electrode active material layer may optionally include a conductive agent. The conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0157] In some embodiments, the negative electrode active material layer may also optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)).

[0158] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as the negative electrode active material, conductive agent, binder, and any other components, in a solvent (a non-limiting example of a solvent is deionized water) to form a negative electrode slurry; coating the negative electrode slurry onto at least one surface of a negative electrode current collector, and then obtaining the negative electrode sheet after drying, cold pressing, and other processes. The surface of the negative electrode current collector coated with the negative electrode slurry can be a single surface of the negative electrode current collector or both surfaces of the negative electrode current collector. The solid content of the negative electrode slurry can be 40wt%~60wt%. The viscosity of the negative electrode slurry at room temperature can be adjusted to 2000mPa·s-10000mPa·s. When coating the negative electrode slurry, the coating unit areal density (dry weight, deducting solvent) can be 75g / m². 2 -220 g / m 2 The compaction density of the negative electrode sheet can be 1.0 g / cm³. 3 - 1.8 g / cm 3 .

[0159] electrolytes

[0160] Electrolytes function to conduct ions between the positive and negative electrode plates. This application does not impose any particular restrictions on the type of electrolyte; it can be selected according to requirements. For example, the electrolyte can be liquid, gel, or completely solid.

[0161] In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent.

[0162] In some embodiments, the electrolyte salt may include one or more of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorophosphate (LiPO2F2), lithium difluorooxalate borate (LiDFOB), lithium dioxalate borate (LiBOB), lithium difluorodioxalate phosphate (LiDFOP), and lithium tetrafluorooxalate phosphate (LiTFOP).

[0163] In some embodiments, the solvent may include ethylene carbonate (EC, ), propylene carbonate (PC, ), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butene carbonate ( One or more of the following: fluoroethylene carbonate (FEC), methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0164] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.

[0165] In some embodiments, the additives in the electrolyte may include, but are not limited to, one or more of fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), trifluoromethyl ethylene carbonate (TFPC), etc.

[0166] Separating membrane

[0167] In some embodiments, the lithium-ion battery also includes a separator. This application does not impose any particular limitation on the type of separator; any known porous separator with good chemical and mechanical stability can be selected.

[0168] In some embodiments, the material of the separator may include one or more of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0169] In some embodiments, the thickness of the separator is 6-40 μm, optionally 13 μm.

[0170] In some embodiments, the positive electrode, negative electrode, and separator can be fabricated into an electrode assembly using a winding process or a stacking process.

[0171] In some embodiments, the lithium-ion battery may include an outer packaging. This outer packaging may be used to encapsulate the electrode assembly and electrolyte described above.

[0172] In some embodiments, the outer packaging of the lithium-ion battery can be a rigid shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the lithium-ion battery can also be a soft pack, such as a pouch-type soft pack. The material of the soft pack can be plastic; further, non-limiting examples of plastic may include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0173] A lithium-ion battery includes at least one battery cell. A lithium-ion battery may include one or more battery cells.

[0174] In this application, unless otherwise specified, "cell battery" refers to the basic unit capable of converting chemical energy into electrical energy, and generally includes at least a positive electrode, a negative electrode, and an electrolyte. During the charging and discharging process of the battery, active ions move back and forth between the positive and negative electrode plates, inserting and extracting. The electrolyte acts as a conductor for the active ions between the positive and negative electrode plates.

[0175] This application does not impose any particular limitation on the shape of the battery cell; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 2 The example shown is a square-structured battery cell 5.

[0176] In some of these embodiments, reference is made to Figure 3 The outer packaging may include a housing 51 and a cover 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover 53 can be placed over the opening to close the receiving cavity. The positive electrode, negative electrode, and separator may be formed into an electrode assembly 52 by a winding process or a stacking process. The electrode assembly 52 is encapsulated within the receiving cavity. Electrolyte is immersed in the electrode assembly 52. ​​The number of electrode assemblies 52 contained in the battery cell 5 may be one or more, which can be selected by those skilled in the art according to actual needs.

[0177] The lithium-ion battery can be either battery module 4 or battery pack 1.

[0178] A battery module includes at least one battery cell. The number of battery cells in a battery module can be one or more, and those skilled in the art can select an appropriate number based on the application and capacity of the battery module.

[0179] Figure 4 This is battery module 4, used as an example. (See reference...) Figure 4 In battery module 4, multiple battery cells 5 can be arranged sequentially along the length of battery module 4. Of course, they can also be arranged in any other manner. Furthermore, these multiple battery cells 5 can be fixed in place using fasteners.

[0180] Optionally, the battery module 4 may also include a housing with a receiving space in which multiple battery cells 5 are received.

[0181] In some embodiments, the battery modules described above can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more. Those skilled in the art can select an appropriate number according to the application and capacity of the battery pack.

[0182] Figure 5 and Figure 6This is battery pack 1 as an example. (See reference...) Figure 5 and Figure 6 The battery pack 1 may include a battery box and multiple battery modules 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3, with the upper body 2 covering the lower body 3 to form a closed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery box.

[0183] In addition, this application also provides an electrical device, which includes the lithium-ion battery provided in this application. The lithium-ion battery can be used as a power source for the electrical device or as an energy storage unit for the electrical device. The electrical device may include, but is not limited to, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc. Among them, mobile devices may be, for example, mobile phones, laptops, etc.; electric vehicles may be, for example, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc., but are not limited to.

[0184] As an electrical device, lithium-ion batteries can be selected based on its usage requirements.

[0185] Figure 6 Here is an example of an electrical device 6. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of lithium-ion batteries for this electrical device, a battery pack or battery module can be used.

[0186] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a slim and lightweight design and can use lithium-ion batteries as their power source.

[0187] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where the technology or conditions are not specified in the embodiments, they are performed according to the technology or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0188] I. Preparation of the positive electrode sheet

[0189] Example 1

[0190] Step S1: Apply polycrystalline lithium-rich manganese-based cathode material Li with Dv50=6.0μm, SPAN=1.0, and TD=2.1g / cm3... 1.13 Ni 0.29 Co 0.03 Mn 0.54 Mg 0.02O2 (first active material) and Li, a single-crystal lithium-rich manganese-based cathode material with Dv50=2.5μm, SPAN=1.4, and TD=2.1g / cm3. 1.2 Ni 0.19 Mn 0.59 Al 0.02 O2 (second active material) was added to a 5L stirred tank at a mass ratio of 2.33:1 and premixed for 30 minutes to prepare a mixture of lithium-rich manganese-based cathode materials.

[0191] Step S2: Continue adding conductive agent acetylene black (SP) and binder polyvinylidene fluoride (PVDF) to the mixing tank for a second dry mixing process of 30 minutes; finally, add solvent N-methylpyrrolidone (NMP) and rapidly stir under vacuum to form a slurry. The mass ratio of the lithium-rich manganese-based cathode material mixture:acetylene black:polyvinylidene fluoride is 96:2:2, and the solid content of the slurry is 70 wt%.

[0192] Step S3: The slurry is uniformly coated on both sides of an aluminum foil with a thickness of 12 μm. The coated electrode is then dried in an oven at 100℃-130℃ for half an hour before being removed. The positive electrode active material loading of the electrode is 13.5 mg / cm³. 2 .

[0193] Example 2-26

[0194] The preparation methods of Examples 2-26 are similar to those of Example 1, with the differences detailed in Tables 1-1 and 1-2.

[0195] The difference between the preparation method of Example 26 and the preparation method of Example 1 includes: using the same amount of ternary cathode material LiNi 0.9 Co 0.0 5Mn 0.05 O2 Replacement for Single-Crystal Lithium-Rich Manganese-Based Cathode Material II.

[0196] Comparative Example 1

[0197] The difference between the preparation method of Comparative Example 1 and the preparation method of Example 1 is that the second active material was not used in Comparative Example 1, and the same amount of the first active material was used to replace the second active material. Everything else is the same.

[0198] Comparative Example 2

[0199] The difference between the preparation method of Comparative Example 2 and the preparation method of Example 1 is that the first active material was not used in Comparative Example 2, and the same amount of the second active material was used to replace the first active material. Everything else is the same.

[0200] Comparative Examples 3-8

[0201] The preparation methods of Comparative Examples 3-8 are similar to those of Example 1, with the differences detailed in Tables 1-2.

[0202] Table 1-1

[0203]

[0204] Table 1-2

[0205]

[0206] In Tables 1-1 and 1-2, n refers to the mass ratio of the first active material to the second active material.

[0207] The lithium-rich manganese-based cathode materials prepared in the above embodiments and comparative examples were tested for particle size distribution span (SPAN), volume distribution particle size (Dv99), compaction density (CPD), and specific surface area (BET). The prepared cathode sheets were also tested for compaction density and elongation. The testing methods are as follows:

[0208] Particle size span (SPAN) and volume distribution particle size (Dv50): Referring to GB / T 19077-2016 / ISO 13320:2009 Particle size distribution by laser diffraction, Dv10, Dv50 and Dv90 were determined using a laser particle size analyzer (Malvin 3000), and then SPAN was calculated according to the formula (Dv90-Dv10) / Dv50.

[0209] The compaction density (CPD) of the cathode material was determined using a UTM7305 electronic pressure testing machine, referring to GB / T 5162-2006 "Graphite Anode Materials for Lithium-ion Batteries".

[0210] Specific surface area (BET): determined according to GB / T 19587-2004, gas adsorption BET method.

[0211] The compaction density of the positive electrode sheet is calculated using the formula PD=M / (d×A). In this formula, M is the mass of a 40mm diameter circular piece cut from the positive electrode sheet, calculated as the average of 10 weighings; d is the thickness of the positive electrode sheet, calculated as the average of 10 thickness measurements; and A is the area of ​​the 40mm diameter circular piece.

[0212] The elongation rate of the positive electrode sheet is calculated using the formula ΔEL%=(L2-L1) / L1×100%. In this formula, L1 is the distance between the marks before cold pressing, which is 1000mm, and L2 is the distance between the marks after cold pressing. The marks are formed as follows: In the central region of the electrode sheet, three line segments extending 1000mm in length are taken at different positions along the width direction of the electrode sheet, and the two endpoints of each line segment are marked. L2 is recorded as the average of the measured distances between the two endpoints of each line segment after cold pressing.

[0213] The test results of the above embodiments and comparative examples are shown in Table 2.

[0214] Table 2

[0215]

[0216] II. Battery fabrication and performance testing

[0217] 1. Preparation of lithium-ion batteries

[0218] 1) Positive electrode sheet: The positive electrode sheet prepared in Example 1 above.

[0219] 2) Preparation of negative electrode sheet

[0220] The negative electrode active material artificial graphite, hard carbon, conductive agent acetylene black, binder styrene-butadiene rubber (SBR), and thickener sodium carboxymethyl cellulose (CMC) are thoroughly mixed in a deionized water solvent system at a weight ratio of 90:5:2:2:1. The mixture is then coated onto both sides of a copper foil, dried, and cold-pressed to obtain the negative electrode sheet.

[0221] 3) Separating membrane

[0222] A 13μm thick porous polyethylene polymer film was selected as the separator.

[0223] 4) Preparation of electrolyte

[0224] The organic solvent was a mixture containing ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC), with a volume ratio of EC, EMC, and DMC of 1:1:1. Thoroughly dried lithium salt LiPF6 was dissolved in the organic solvent and mixed thoroughly in an argon-atmosphere glove box with a water content of <10 ppm to obtain the electrolyte. The concentration of the lithium salt was 1 mol / L.

[0225] 5) Battery manufacturing

[0226] The positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the positive and negative electrodes to provide isolation. After being wound into a square bare cell, it is placed in an aluminum-plastic film, injected with the non-aqueous electrolyte prepared above, and sealed. After processes such as standing, hot and cold pressing, formation, clamping, and capacity testing, a lithium-ion battery is obtained.

[0227] The lithium-ion batteries of Examples 2-26 and Comparative Examples 1-8 are prepared using methods similar to those of the lithium-ion battery in Example 1, but the corresponding cathode materials of the preparation examples or comparative examples are used.

[0228] 2. Preparation of button batteries

[0229] The CR2032 coin cell was assembled in an argon-filled glove box. The assembly sequence from top to bottom was: positive electrode shell, positive electrode sheet prepared in Example 1, separator, negative electrode, steel sheet, spring sheet, and negative electrode shell. After assembly, the cells were left to stand for 6 hours for later use.

[0230] The button cells of Examples 2-26 and Comparative Examples 1-8 are prepared in a similar manner to the button cell of Example 1, but the corresponding cathode materials of the preparation examples or comparative examples are used.

[0231] The lithium-ion batteries prepared in the above embodiments and comparative examples were subjected to cycle performance tests, and the coin cells prepared in the above embodiments and comparative examples were subjected to capacity tests.

[0232] Capacity test: Using a coin cell as the test object, under a voltage range of 2.5V-4.55V, charge it to 4.55V at a rate of 0.1C, and then charge it at a constant voltage of 4.55V until the current is ≤0.05mA. Let it stand for 2 minutes. The charging capacity at this time is recorded as C0. Then discharge it to 2.5V at a rate of 0.1C. The discharge capacity at this time is the initial gram capacity, recorded as D0. The first efficiency is D0 / C0*100%.

[0233] Cyclic test: Using a secondary battery as the test object, under a constant temperature environment of 25℃ or 45℃, charge at a rate of 1C to 4.45V at a voltage of 2.5V-4.45V, then charge at a constant voltage of 4.45V until the current is ≤0.05mA, let stand for 5 minutes, and then discharge at a rate of 1C to 2.5V. Record the discharge capacity. Repeat the above process until the capacity decays to 80%, and record the number of cycles.

[0234] The test results of the above embodiments and comparative examples are shown in Table 3.

[0235] Table 3

[0236]

[0237] As can be seen from the comparison of the results of Examples 1-26 and Comparative Examples 1-8, the lithium-rich manganese-based cathode material provided in this application has suitable particle size span SPAN, volume distribution particle size Dv50, compaction density CPD and specific surface area BET, which is beneficial to improving the compaction density of the electrode, reducing the elongation of the electrode, and also beneficial to improving the cycle performance of the battery.

[0238] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0239] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A lithium-rich manganese-based cathode material, characterized in that, The lithium-rich manganese-based cathode material has a particle size span (SPAN) of 1.6-2.0, a volume distribution particle size (Dv50) of 6.5 μm-10.1 μm, and a compaction density (CPD) of 2.9 g / cm³. 3 -3.3g / cm 3 The specific surface area (BET) is 1.5 m². 2 / g -3.5m 2 / g.

2. The lithium-rich manganese-based cathode material according to claim 1, characterized in that, The lithium-rich manganese-based cathode material includes a first active material and a second active material, and the first active material and the second active material have different volume distribution particle sizes.

3. The lithium-rich manganese-based cathode material according to claim 2, characterized in that, The volume distribution particle size Dv50 of the first active material is 6μm-10μm, and the volume distribution particle size Dv50 of the second active material is 1.5μm-3.5μm.

4. The lithium-rich manganese-based cathode material according to any one of claims 2 to 3, characterized in that, The first active material is a polycrystalline lithium-rich manganese-based cathode material, and the second active material is one or more of a single-crystal lithium-rich manganese-based cathode material, a polycrystalline lithium-rich manganese-based cathode material, and a lithium-nickel composite oxide.

5. The lithium-rich manganese-based cathode material according to claim 4, characterized in that, The first active material is a polycrystalline lithium-rich manganese-based cathode material, and the second active material is a monocrystalline lithium-rich manganese-based cathode material.

6. The lithium-rich manganese-based cathode material according to any one of claims 2 to 5, characterized in that, The mass ratio of the first active material to the second active material is (1.5-9):

1.

7. The lithium-rich manganese-based cathode material according to any one of claims 2 to 6, characterized in that, The volume distribution particle size Dv10 of the first active material is 0.5μm-2.5μm.

8. The lithium-rich manganese-based cathode material according to any one of claims 2 to 7, characterized in that, The volume distribution particle size Dv99 of the first active material is 7μm-20μm.

9. The lithium-rich manganese-based cathode material according to any one of claims 2 to 8, characterized in that, The volume distribution particle size Dv10 of the second active material is 0.5μm-2.5μm.

10. The lithium-rich manganese-based cathode material according to any one of claims 2 to 9, characterized in that, The volume distribution particle size Dv99 of the second active material is 1μm-7.5μm.

11. The lithium-rich manganese-based cathode material according to any one of claims 2 to 10, characterized in that, The particle size span (SPAN) of the first active material is 0.5-1.

2.

12. The lithium-rich manganese-based cathode material according to any one of claims 2 to 11, characterized in that, The particle size span (SPAN) of the second active material is 1.0-1.

8.

13. The lithium-rich manganese-based cathode material according to any one of claims 2 to 12, characterized in that, The specific surface area (BET) of the first active material is 1.3 m². 2 / g -1.7m 2 / g.

14. The lithium-rich manganese-based cathode material according to any one of claims 2 to 13, characterized in that, The specific surface area (BET) of the second active material is 1.5 m². 2 / g -2.1m 2 / g.

15. The lithium-rich manganese-based cathode material according to any one of claims 2 to 14, characterized in that, The compaction density (PD) of the first active material is 2.7 g / cm³. 3 -3.1g / cm 3 .

16. The lithium-rich manganese-based cathode material according to any one of claims 2 to 14, characterized in that, The compaction density (PD) of the second active material is 2.5 g / cm³. 3 -2.8g / cm 3 .

17. The lithium-rich manganese-based cathode material according to any one of claims 2 to 16, characterized in that, The true density of the first active material is 4.2 g / cm³. 3 -4.45g / cm 3 .

18. The lithium-rich manganese-based cathode material according to any one of claims 2 to 17, characterized in that, The true density of the second active material is 4.1 g / cm³. 3 -4.35g / cm 3 .

19. The lithium-rich manganese-based cathode material according to any one of claims 2 to 18, characterized in that, The tap density (TD) of the first active material is ≥1.8 g / cm³. 3 .

20. The lithium-rich manganese-based cathode material according to any one of claims 2 to 19, characterized in that, The tap density (TD) of the second active material is ≥1.8 g / cm³. 3 .

21. The lithium-rich manganese-based cathode material according to any one of claims 2 to 20, characterized in that, The chemical formula of the first active material is Li[Li x Ni a Co b Mn c M d ]O 2-e Z e , where x+a+b+c+d=1, x>0, a+b+c+d<1, 0<b≤0.1, 0≤e≤0.2, element M includes one or more of Te, Se, Mg, Nb, Cr, Ce, Fe, Ta, B, V, Ti, Sn, W and Mo, and element Z includes one or more of F, Cl and Br.

22. The lithium-rich manganese-based cathode material according to any one of claims 2 to 21, characterized in that, The chemical formula of the second active material is Li[Li x1 Ni a1 Co b1 Mn c1 M1 d1 ]O 2-e1 Z1 e1 Where x1+a1+b1+c1+d1=1, x1>0, a1+b1+c1+d1<1, 0<b1≤0.1, 0≤e≤0.2, M1 element includes one or more of Te, Se, Mg, Nb, Cr, Ce, Fe, Ta, B, V, Ti, Sn, W and Mo, and Z1 element includes one or more of F, Cl and Br.

23. The lithium-rich manganese-based cathode material according to claim 4, characterized in that, The lithium-nickel composite oxide is a lithium-containing nickel-cobalt-manganese metal oxide.

24. The lithium-rich manganese-based cathode material according to claim 23, characterized in that, The lithium-nickel composite oxide further includes one or more of cobalt, manganese and aluminum, and the molar percentage of nickel in all metal elements except lithium is ≥80%.

25. A method for preparing a lithium-rich manganese-based cathode material, characterized in that, Includes the following steps: The lithium-rich manganese-based cathode material is prepared by mixing a first active material and a second active material; wherein the first active material and the second active material have different volume distribution particle sizes. The lithium-rich manganese-based cathode material has a particle size span (SPAN) of 1.6-2.0, a volume distribution particle size (Dv50) of 6.5 μm-10.1 μm, and a compaction density (CPD) of 2.9 g / cm³. 3 -3.3g / cm 3 The specific surface area (BET) is 1.5 m². 2 / g -3.5m 2 / g.

26. A positive electrode plate, characterized in that, The positive electrode comprises the lithium-rich manganese-based positive electrode material according to any one of claims 1 to 24.

27. The positive electrode sheet according to claim 26, characterized in that, The compaction density of the positive electrode sheet is ≥2.86 g / cm³. 3 .

28. The positive electrode sheet according to any one of claims 26 to 27, characterized in that, The elongation of the positive electrode sheet is ≤0.7%.

29. A lithium-ion battery, characterized in that, Includes the positive electrode sheet as described in any one of claims 26 to 28.

30. An electrical device, characterized in that, It includes at least one of the positive electrode sheet according to any one of claims 26 to 28 and the lithium-ion battery according to claim 29.

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