Lithium-ion battery, lithium supplement, positive electrode and power-consuming device

Abstract

The present application provides a lithium-ion battery, a lithium supplement, a positive electrode plate and an electric device, wherein the lithium-ion battery comprises a positive electrode plate, the positive electrode plate comprises a positive current collector and a positive electrode active material layer disposed on at least one surface of the positive current collector, the positive electrode active material layer comprises a positive electrode active material and a lithium supplement; the lithium supplement comprises a core and a shell covering at least part of the surface of the core, the core comprises a second conductive agent, the shell comprises a lithium supplement material, a first conductive agent and a catalyst, the lithium supplement material comprises a lithium-containing carbon oxide, and the volume average particle size Dv50 of the lithium supplement is 2μm~10μm. The lithium-ion battery provided by the present application has a relatively excellent cycle life.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a lithium-ion battery, a lithium supplement, a positive electrode plate and an electrical device. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] In recent years, as the application scope of lithium-ion batteries has become more and more extensive, lithium-ion batteries are widely used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, as well as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields. As lithium-ion batteries have made great progress, higher requirements have been put forward for their cycle life and other performance. Summary of the invention

[0004] The present application provides a lithium-ion battery, a lithium supplement, a positive electrode plate and an electrical device, which can increase the cycle life of the battery.

[0005] In order to achieve the above-mentioned object, the first aspect of the present application provides a lithium-ion battery, comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode active material layer, wherein the positive electrode active material layer comprises a positive electrode active material and a lithium supplement;

[0006] The lithium supplement agent includes a core and a shell covering at least a portion of the surface of the core, the core includes a second conductive agent, the shell includes a lithium supplement material, a first conductive agent and a catalyst, the lithium supplement material includes a lithium-containing carbon oxide, and the volume average particle size Dv50 of the lithium supplement agent is 2μm~10μm.

[0007] In some embodiments of the present application, the shell covers the entire surface of the core.

[0008] In some embodiments of the present application, at least a portion of the core is embedded in the shell.

[0009] In some embodiments of the present application, the thickness d of the shell does not exceed 25% of the volume average particle size Dv50 of the lithium supplement.

[0010] In some embodiments of the present application, the volume average particle size Dv50 of the lithium supplement is 2 μm to 10 μm.

[0011] In some embodiments of the present application, the volume average particle size Dv50 of the lithium supplement is 3 μm to 8 μm.

[0012] In some embodiments of the present application, the lithium-containing carbon oxide compound satisfies the chemical formula Li 2 Cx O y , 1≤x≤4, 3≤y≤6.

[0013] In some embodiments of the present application, the lithium-containing carbon oxide compound includes Li 2 CO 3 , Li 2 C 2 O 4 , Li 2 C 4 O 4 , Li 2 C 4 O 6 and Li 2 C 3 O 5 One or more of the .

[0014] In some embodiments of the present application, the lithium-containing carbon oxide compound includes Li 2 CO 3 , Li 2 C 2 O 4 and Li 2 C 4 O 4 One or more of the .

[0015] In some embodiments of the present application, the first conductive agent and the second conductive agent each independently include one or more of a zero-dimensional conductive carbon material, a one-dimensional conductive carbon material, a two-dimensional conductive carbon material, and a three-dimensional conductive carbon material.

[0016] In some embodiments of the present application, the first conductive agent and the second conductive agent each independently include at least one of a one-dimensional conductive carbon material and a two-dimensional conductive carbon material.

[0017] In some embodiments of the present application, the catalyst comprises compound X a Y b and / or transition metal elements, wherein X comprises one or more of Ni, Co, Mn, Fe, Cu, Ti, Nb, Mg, Cr, Y comprises one or more of O, C, N, and a and b make the compound X a Y b The algebraic sum of the valences of the elements in is zero.

[0018] In some embodiments of the present application, the transition metal element includes one or more of nickel element, cobalt element, manganese element, iron element, copper element, titanium element, niobium element, magnesium element and chromium element.

[0019] In some embodiments of the present application, the mass percentage of the catalyst to the lithium supplement agent is ω2, 0.5%≤ω2≤20%.

[0020] In some embodiments of the present application, 1%≤ω2≤10%.

[0021] In some embodiments of the present application, at least one of the following conditions is met:

[0022] (1) The zero-dimensional conductive carbon material comprises carbon nanodots;

[0023] (2) The one-dimensional conductive carbon material includes one or more of carbon nanotubes, carbon nanowires and carbon nanofibers;

[0024] (3) The two-dimensional conductive carbon material includes graphene;

[0025] (4) The three-dimensional conductive carbon material includes carbon black.

[0026] In some embodiments of the present application, the carbon black includes one or more of superconducting carbon black, acetylene black and Ketjen black.

[0027] In some embodiments of the present application, the total mass of the first conductive agent and the second conductive agent accounts for a mass percentage of the lithium supplement agent of ω1, 1%≤ω1≤40%.

[0028] In some embodiments of the present application, 2%≤ω1≤21%.

[0029] In some embodiments of the present application, based on the total mass of the positive electrode active material and the lithium supplement, the mass percentage of the lithium supplement is ω, 0<ω≤10%.

[0030] In some embodiments of the present application, the positive electrode active material includes a lithium iron phosphate active material.

[0031] In some embodiments of the present application, the lithium-ion battery further comprises a negative electrode plate, and the negative electrode plate satisfies the following relation with the positive electrode plate: 1≤N / P≤1.1, wherein N / P=(negative electrode surface density×negative electrode active material content ratio×negative electrode gram capacity) / (positive electrode surface density×positive electrode active material content ratio×positive electrode gram capacity).

[0032] The lithium-ion battery provided in the present application includes a lithium supplement agent, and the lithium supplement agent is a core-shell structure, wherein a lithium-containing carbon oxide compound is arranged in the outer shell as a lithium supplement material, so that the lithium supplement material can achieve a relatively sufficient contact with the electrolyte and shorten its lithium delithiation path, which is conducive to a more complete decomposition of the lithium supplement material, so that the capacity of the lithium supplement material and the lithium supplement effect can be fully exerted. At the same time, the outer shell contains a catalyst and a first conductive agent, wherein the catalyst is conducive to reducing the decomposition voltage of the lithium supplement material, so that its capacity can be increased, thereby facilitating the effective improvement of the positive electrode capacity and cycle performance; and the first conductive agent is conducive to the improvement of the positive electrode conductivity. At the same time, the lithium supplement material, catalyst and first conductive agent in the outer shell of the lithium supplement agent of the present application can also promote each other, cooperate with each other to comprehensively improve the capacity and kinetic performance of the lithium supplement agent and the positive electrode, and further, the kinetic performance can be a fast charging performance. After the outer shell is consumed, the second conductive agent contained in the inner core is not easy to decompose and can still exist stably, and can maintain the integrity of its own structure. It can serve as a supporting skeleton to support the structure of the lithium supplement agent, thereby effectively reducing the collapse of the lithium supplement agent particles, thereby greatly improving the structural stability of the lithium supplement agent and the positive electrode.

[0033] The second aspect of the present application also provides a lithium supplement agent, including a core and a shell covering at least a portion of the surface of the core, the core containing a second conductive agent, the shell containing a lithium supplement material, a first conductive agent and a catalyst, the lithium supplement material comprising a lithium-containing carbon oxide compound, and the volume average particle size Dv50 of the lithium supplement agent is 2 μm~10 μm.

[0034] In some embodiments of the present application, the lithium supplement is the lithium supplement in the lithium ion battery of the first aspect of the present application.

[0035] A third aspect of the present application provides a positive electrode plate, comprising a positive electrode active material layer, wherein the positive electrode active material layer contains the lithium supplement agent of the second aspect of the present application.

[0036] A fourth aspect of the present application provides an electrical device, comprising the lithium-ion battery of the first aspect of the present application.

[0037] The electric device of the present application includes the lithium-ion battery provided by the present application, and thus has at least the same advantages as the lithium-ion battery.

[0038] The details of one or more embodiments of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to better describe and illustrate the embodiments or examples provided by the present application, reference may be made to one or more drawings. The additional details or examples used to describe the drawings should not be considered as limiting the scope of the disclosed application, the embodiments or examples currently described, and any of the best modes of these applications currently understood. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0040] Figure 1 This is a morphology diagram of a lithium supplement according to one embodiment of the present application.

[0041] Figure 2 It is a schematic diagram of a battery cell according to an embodiment of the present application.

[0042] Figure 3 for Figure 2 An exploded view of a battery cell according to an embodiment of the present application is shown.

[0043] Figure 4 It is a schematic diagram of a battery module according to one embodiment of the present application.

[0044] Figure 5 A schematic diagram of a battery pack according to an embodiment of the present application.

[0045] Figure 6 for Figure 5 An exploded view of a battery pack according to an embodiment of the present application is shown.

[0046] Figure 7 A schematic diagram of an electrical device using a lithium-ion battery as a power source according to an embodiment of the present application.

[0047] Description of reference numerals:

[0048] 1 battery pack; 2 upper box; 3 lower box; 4 battery module; 5 battery cell; 51 shell; 52 electrode assembly; 53 cover plate; 6 electrical device. DETAILED DESCRIPTION

[0049] Below, some embodiments of the lithium-ion battery and the electrical device of the present application are described in detail with appropriate reference to the drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0050] "Scope" disclosed in the present application can be limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be including end values ​​or excluding end values, and any end value can be included or not included independently, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 listed, and if the maximum range values ​​3,4 and 5 are also listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation for these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to listing the parameter as, for example, integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9 and 10.

[0051] In the present application, "plurality", "multiple" and the like, unless otherwise specified, refer to a number greater than or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0052] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0053] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment or implementation of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments. The "implementation methods" mentioned herein have a similar understanding.

[0054] Those skilled in the art will appreciate that, in the methods of each embodiment or example, the order in which each step is written does not mean a strict order of execution and does not constitute any limitation on the implementation process, and the detailed order of execution of each step should be determined by its function and possible internal logic. If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) can be added to the method in any order, for example, the method may include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0055] In the present application, in the open technical features or technical solutions described by the words "contain", "include", "comprise", etc., unless otherwise specified, additional members other than the listed members are not excluded, and it can be regarded as providing both closed features or solutions consisting of the listed members and open features or solutions including additional members in addition to the listed members. For example, A includes a1, a2 and a3. Unless otherwise specified, it may also include other members or may not include additional members. It can be regarded as providing both the feature or solution of "A consists of a1, a2 and a3" and the feature or solution of "A not only includes a1, a2 and a3, but also includes other members". In the present application, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0056] In this application, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If there are multiple "options" in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "option" is independent.

[0057] Generally, during the first charge and discharge process of lithium-ion batteries, a large amount of solid electrolyte interface film will be produced on the surface of the negative electrode of the battery, which consumes the limited lithium ions and electrolyte in the battery, causing irreversible capacity loss and resulting in a decrease in the battery cycle life. Based on this, positive electrode lithium supplement additives can compensate for the irreversible capacity loss of lithium-ion batteries during the first charge process to a certain extent, and improve the battery capacity and cycle performance to a certain extent.

[0058] However, the commonly used positive electrode lithium replenishing additives are usually aggregates of lithium replenishing material particles. This type of lithium replenishing additive is usually a solid structure. After the outer circle is decomposed, the inner circle may not be able to decompose or cannot be completely decomposed due to the longer internal decomposition path and the more difficult decomposition. As a result, the material in the inner circle cannot function or cannot fully function, making it impossible for the material's lithium replenishing function to be fully exerted. The capacity of the lithium replenishing additive is relatively low, and the effect of improving the capacity and cycle life is limited.

[0059] Based on this, the present application provides a lithium-ion battery, in which a core-shell structured lithium-supplementing additive is provided in the positive electrode active material layer of the lithium-ion battery, and the lithium-supplementing material is arranged in the outer shell of the lithium-supplementing additive, which is conducive to the complete decomposition of the lithium-supplementing material, so that the lithium-supplementing effect of the lithium-supplementing material can be fully exerted, thereby facilitating the effective improvement of the battery capacity and cycle performance.

[0060] In a first aspect, the present application provides a lithium-ion battery, comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode active material layer, wherein the positive electrode active material layer comprises a positive electrode active material and a lithium supplement;

[0061] The lithium supplement agent includes a core and a shell covering at least a portion of the surface of the core, the core includes a second conductive agent, the shell includes a lithium supplement material, a first conductive agent and a catalyst, the lithium supplement material includes a lithium-containing carbon oxide, and the volume average particle size Dv50 of the lithium supplement agent is 2μm~10μm.

[0062] In order to solve the problem that the lithium replenishing effect of the aforementioned lithium replenishing additive cannot be fully exerted, the lithium replenishing additive can also be designed into a hollow structure to improve the contact between the lithium replenishing additive and the electrolyte and the lithium de-lithiation path, thereby promoting the full exertion of the lithium replenishing capacity. However, after a part of the outer layer material is consumed, the hollow structure of the lithium replenishing additive is prone to structural collapse, which affects the structural stability and cycle stability of the positive electrode.

[0063] The lithium-ion battery provided by the present application includes a lithium supplement agent, and the lithium supplement agent is a core-shell structure, wherein, compared with the structure in which the lithium supplement material is arranged in the core and the conductive agent and the catalyst are arranged in the shell, the present application arranges the carbon oxide containing lithium as the lithium supplement material in the shell, which can reduce the barrier of the shell to the electrolyte when the lithium supplement material is arranged in the core, so that the lithium supplement material and the electrolyte can achieve more sufficient contact, and shorten its lithium de-lithiation path, which is conducive to the full decomposition of the lithium supplement material, so that the capacity of the lithium supplement material and the lithium supplement effect can be more fully exerted. At the same time, the shell contains a catalyst and a first conductive agent, wherein the catalyst is conducive to reducing the decomposition voltage of the lithium supplement material, so that its capacity can be increased, thereby facilitating the effective improvement of the positive electrode capacity and cycle performance; and the first conductive agent is conducive to the improvement of the positive electrode conductivity. Compared with the structure in which the core includes a conductive agent and the shell only includes a lithium supplement material and a catalyst, the shell structure of the present application can effectively improve the conductivity of the lithium supplement; compared with the structure in which the core includes a second conductive agent and the shell only includes a lithium supplement material and a first conductive agent, the shell structure of the present application can effectively improve the capacity of the lithium supplement. At the same time, the lithium supplement material, catalyst and first conductive agent in the shell of the lithium supplement of the present application can also promote each other and cooperate with each other to comprehensively improve the capacity and kinetic performance of the lithium supplement and the positive electrode. Further, the kinetic performance can be a fast charging performance.

[0064] In addition, after the lithium-containing carbon oxide compound is decomposed by delithiation, it is not easy to leave holes in the original position, which can reduce the damage to the overall structure of the positive electrode. Moreover, after the outer shell is consumed, the second conductive agent contained in the inner core is not easy to decompose, and can still exist stably, and can maintain the integrity of its own structure. It can serve as a supporting skeleton to support the structure of the lithium supplement agent, so that the collapse of the lithium supplement agent particles can be effectively reduced, thereby greatly improving the structural stability of the lithium supplement agent and the positive electrode. In this way, compared with the solution of designing the lithium supplement additive into a hollow structure, the lithium supplement agent of the present application can effectively play the role of lithium supplementation, improve the capacity and cycle life of the positive electrode, and at the same time improve the structural stability and cycle stability of the positive electrode.

[0065] It should be noted that for the various parameters of the positive electrode sheet in the following text, you can take samples from fresh batteries for testing according to the following steps: disassemble the fresh battery and take out the positive electrode sheet, soak the positive electrode sheet in dimethyl carbonate for a certain period of time (for example, 2h~10h); then take out the positive electrode sheet and dry it at a certain temperature and time (for example, 60℃, more than 4h), take out the positive electrode sheet after drying, and then the positive electrode sheet can be used for testing. For example, the positive electrode sheet can be subjected to a cross-sectional polishing (CP) test to observe the cross section of the positive electrode sheet along the thickness direction, and the positive electrode active material and the lithium supplement can be distinguished by different morphologies. In addition, for the various parameters of the lithium supplement, fresh lithium supplement can be used for sampling and testing.

[0066] It should be noted that the "fresh battery" refers to a battery that has been assembled but not cycled; the "fresh lithium supplement" refers to the lithium supplement used in preparing the positive electrode plate, for example, it can be the lithium supplement used in forming the positive electrode slurry.

[0067] As an example, you can use ceramic scissors to cut the dried positive electrode into several 6mm×6mm discs, and stick the discs used for testing on the sample stage coated with paraffin, and make the sample slightly protrude (<1mm) from the edge of the sample stage. Then set the polishing voltage and time for polishing (e.g., 50min for the positive electrode at 7.5kV; parameter settings: mode: In-lens, voltage: 10KV, aperture: 30μm, working distance: 4.5mm). After that, you can randomly select any several (e.g., 5 or more) areas within the field of view, focus and take pictures at different magnifications, and collect the cross-sectional morphology information of the electrode.

[0068] As an example, the above-mentioned disc for testing can be attached to a sample stage coated with paraffin, and the sample can be slightly protruded (<1mm) from the edge of the sample stage. Then set the polishing voltage and time for polishing (e.g., 50min at 7.5kV for the positive electrode; parameter settings: mode: In-lens, voltage: 20kV, aperture: 60um, working distance: 8.5mm). After that, any several (e.g., 5 or more) areas within the line of sight can be randomly selected for elemental energy spectrum (EDS) analysis. Through EDS analysis, the elements (e.g., C elements, metal elements, etc.) contained in the lithium supplement and their content can be measured.

[0069] In some embodiments, the shell covers the entire surface of the core. This, on the one hand, is conducive to further improving the structural stability of the lithium supplement and the positive electrode; on the other hand, it is conducive to further improving the capacity, cycle life and conductivity.

[0070] In some embodiments, at least a portion of the core is embedded in the shell, which is beneficial to further improve the structural stability of the lithium supplement and the structural stability of the positive electrode.

[0071] In some embodiments, the inner core of the lithium supplement contains a second conductive agent, which, after the outer shell is consumed, can not only serve as a supporting skeleton to support the structure of the lithium supplement and improve the structural stability of the lithium supplement and the positive electrode, but also play a conductive role to further improve the conductivity of the positive electrode.

[0072] In some embodiments, the core comprises an aggregate of particles of a second conductive agent. Thus, it is beneficial to further improve the structural stability of the core, enabling it to maintain the integrity of its own structure and still exist stably after the outer shell is consumed, thereby further enhancing the structural stability of the positive electrode and further improving the electrical conductivity.

[0073] In some embodiments, the thickness d of the outer shell does not exceed 25% of the volume average particle size Dv50 of the lithium supplement agent, i.e., 0 < d / Dv50 ≤ 0.25. For example, d can be 25%, 23%, 20%, 18%, 15%, 13%, 10%, 7%, 5%, 3%, 1%, 0.5%, 0.3%, 0.1% of Dv50 or within the range composed of any of the above values. Thus, it is beneficial to reduce the diffusion distance of lithium ions released by the decomposition of the lithium supplement material, improve the kinetics, and enhance the fast charging performance; at the same time, it can also reduce the decomposition voltage, improve the capacity and cycle life.

[0074] The thickness of the outer shell has the meaning well-known in the art and can be measured by instruments and methods known in the art. For example, the method described above can be used to perform a cross-section polishing (CP) test on the positive electrode sheet for testing, observe the cross-section of the positive electrode sheet along the thickness direction, and distinguish the positive electrode active material and the lithium supplement agent through different morphologies. The thickness of the outer shell can be obtained through the morphology presented by the lithium supplement agent.

[0075] In some embodiments, the volume average particle size Dv50 of the lithium supplement agent is 2 μm to 10 μm. For example, the Dv50 can be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm or within the range composed of any of the above values. Thus, it is beneficial to reduce the diffusion distance of lithium ions released by the decomposition of the lithium supplement material, increase the transmission rate of lithium ions, and improve the kinetics and fast charging performance.

[0076] In some embodiments, the volume average particle size Dv50 of the lithium supplement agent is 3 μm to 8 μm. For example, the Dv50 can be 3 μm, 3.5 μm, 4.5 μm, 5.5 μm, 6.5 μm, 7.5 μm, 8 μm or within the range composed of any of the above values. Thus, it is beneficial to further increase the transmission rate of lithium ions released by the decomposition of the lithium supplement material, thereby facilitating the further improvement of the kinetics and fast charging performance.

[0077] The volume average particle size Dv50 of the lithium supplement is well known in the art, which indicates the particle size corresponding to when the cumulative volume distribution percentage of the material reaches 50%, and can be measured using instruments and methods known in the art. For example, the fresh lithium supplement can be measured using a laser particle size analyzer with reference to GB / T 19077-2016. The test instrument can be a Mastersizer 3000 laser particle size analyzer from Malvern Instruments Ltd., UK.

[0078] In some embodiments, the lithium-containing carbon oxide compound satisfies the chemical formula Li 2 C x O y , 1≤x≤4, 3≤y≤6. In this way, the decomposition voltage of the lithium supplement agent can be made as low as possible to reduce the damage to the electrolyte caused by the high decomposition voltage of the lithium supplement material and reduce the impact on the battery cycle performance.

[0079] In some embodiments, the lithium-containing carbon oxide comprises Li 2 CO 3 , Li 2 C 2 O 4 , Li 2 C 4 O 4 , Li 2 C 4 O 6 , Li 2 C 3 O 5 One or more of the following, which can be selected as Li 2 CO 3 , Li 2 C 2 O 4 , Li 2 C 4 O 4 In this way, the decomposition voltage of the lithium supplementing agent can be further reduced, thereby further reducing the damage to the electrolyte caused by the decomposition of the lithium supplementing material, and further reducing the impact on the battery cycle performance.

[0080] In some embodiments, the lithium-containing carbon oxide compound contains a hollow structure, which can shorten the escape path of lithium ions released by the decomposition of the lithium supplement material, improve the kinetics, help improve the fast charging performance of the battery, and effectively reduce the decomposition voltage of the lithium supplement material.

[0081] In some embodiments, the first conductive agent and the second conductive agent each independently include one or more of a zero-dimensional conductive carbon material, a one-dimensional conductive carbon material, a two-dimensional conductive carbon material, and a three-dimensional conductive carbon material. The first conductive agent and the second conductive agent can respectively improve the conductivity of the lithium supplement agent, thereby increasing its capacity and capacity performance.

[0082] In some embodiments, the first conductive agent and the second conductive agent each independently include one or more of a one-dimensional conductive carbon material and a two-dimensional conductive carbon material.

[0083] The length or area of ​​the one-dimensional conductive carbon material and the two-dimensional conductive carbon material is relatively larger, and can achieve line contact or surface contact. Therefore, when they are in the outer shell, they can load or connect more particles of lithium supplement material, so that the capacity of the lithium supplement agent is higher; and the carbon skeleton composed of the one-dimensional conductive carbon material and / or the two-dimensional conductive carbon material has better continuity, which can further improve the structural stability of the lithium supplement agent and the positive electrode.

[0084] It is understood that "A and / or B" in this application refers to one or both of A and B. For example, "one-dimensional conductive carbon material and / or two-dimensional conductive carbon material" may include three schemes: (1) one-dimensional conductive carbon material and two-dimensional conductive carbon material; (2) one-dimensional conductive carbon material; (3) two-dimensional conductive carbon material.

[0085] In some embodiments, the first conductive agent and the second conductive agent each independently include a two-dimensional conductive carbon material. This is beneficial to further increase the capacity of the lithium supplement agent and further improve the structural stability of the lithium supplement agent and the positive electrode.

[0086] It can be understood that the first conductive agent and the second conductive agent can be the same or different. Optionally, the first conductive agent and the second conductive agent are the same.

[0087] In some embodiments, the zero-dimensional conductive carbon material includes carbon nanodots.

[0088] In some embodiments, the one-dimensional conductive carbon material includes one or more of carbon nanotubes, carbon nanowires, and carbon nanofibers.

[0089] In some embodiments, the two-dimensional conductive carbon material includes graphene.

[0090] In some embodiments, the three-dimensional conductive carbon material includes carbon black.

[0091] In some embodiments of the present application, the carbon black includes one or more of superconducting carbon black, acetylene black and Ketjen black.

[0092] In some embodiments, the total mass of the first conductive agent and the second conductive agent accounts for a mass percentage of the lithium supplement agent of ω1, 1%≤ω1≤40%. For example, ω1 can be 1%, 5%, 10%, 15%, 20%, 23%, 25%, 27%, 30%, 32%, 34%, 36%, 38%, 40% or within the range of any of the above values. In this way, on the one hand, the conductive agent can build a good conductive skeleton, reduce the powder resistivity of the lithium supplement agent, effectively improve its conductivity, and promote the decomposition of the conductive material, improve the decomposition efficiency of the conductive material, and thus improve the capacity and cycle life; on the other hand, it can also reduce the percentage of the conductive agent in the lithium supplement agent to the mass percentage of the lithium supplement material, thereby increasing the content of the lithium supplement material, which is conducive to further improving the capacity of the lithium supplement agent.

[0093] As an example, the total mass of the first conductive agent and the second conductive agent accounts for a mass percentage of the lithium supplement agent of ω1, and a fresh lithium supplement agent sample can be used for testing. For example, referring to GB / T 20123-2006 / ISO 15350:2000 JJG 395-1997, a fresh lithium supplement agent sample can be taken for sulfur-carbon testing, thereby determining ω1. The specific test method is as follows: weigh an appropriate amount of sample into a special crucible, add an appropriate amount of flux and mix evenly, and burn the sample in oxygen to convert carbon and sulfur into CO 2 、SO 2 After entering the absorption cell, the detector converts it into a corresponding signal. This signal is sampled by the computer and converted into a signal corresponding to CO after linear correction. 2 、SO 2 The value proportional to the concentration is then accumulated during the entire analysis process. After the analysis is completed, this accumulated value is divided by the weight value in the computer, multiplied by the correction factor, and the blank is subtracted to obtain the percentage of carbon and sulfur in the sample.

[0094] In some embodiments, ω1 is 2%≤ω1≤21%. For example, ω1 can be 2%, 3%, 4%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, or within a range of any of the above values. This is beneficial to further improve the positive electrode capacity and cycle life.

[0095] In some embodiments, the catalyst comprises compound X a Y b and / or transition metal elements, wherein X comprises one or more of Ni, Co, Mn, Fe, Cu, Ti, Nb, Mg, and Cr, Y comprises one or more of O, C, and N (nitrogen), and a and b make the compound X a Y bThe algebraic sum of the valence of each element in the catalyst is 0. The catalyst is beneficial to reduce the decomposition voltage of the lithium supplement material and improve the capacity and lithium supplement efficiency.

[0096] In some embodiments, the transition metal element includes one or more of nickel element, cobalt element, manganese element, iron element, copper element, titanium element, niobium element, magnesium element and chromium element.

[0097] In some embodiments, the mass percentage of the catalyst in the lithium supplement agent is ω2, 0.5%≤ω2≤20%. For example, ω2 can be 0.5%, 1%, 3%, 5%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20% or within the range of any of the above values. In this way, on the one hand, the actual contact area between the catalyst and the lithium supplement material can be increased, the catalytic decomposition effect of the catalyst on the lithium supplement material can be improved, the decomposition efficiency of the lithium supplement material can be improved, and the lithium supplement material can be decomposed as completely as possible, thereby improving the capacity of the lithium supplement agent; on the other hand, the occupation of the mass percentage of the catalyst in the lithium supplement agent to the lithium supplement material can be reduced, thereby increasing the content of the lithium supplement material, thereby facilitating further increasing the capacity of the lithium supplement agent.

[0098] As an example, the mass percentage of the catalyst in the lithium supplement is ω2, and a fresh lithium supplement sample can be used for testing. For example, referring to EPA 6010D-2018, a fresh lithium supplement sample can be taken for ICP (inductively coupled plasma) testing to test the total content of all metal elements in the sample except lithium, thereby determining ω2. The specific test method example is as follows: weigh 0.2g of the sample, add 12mL of reverse aqua regia, use a microwave digester to digest, transfer to a volumetric flask after digestion, use a pipette to take 1mL of the sample and dilute to 100mL, fix the volume, add 1mL~2mL of nitric acid to provide an acidic test environment; then use a tester (such as ICP-OES, Thermo ICAP7400ICP) for testing. Among them, the quantitative method used is the standard curve method.

[0099] In some embodiments, ω2 is 1%≤ω2≤10%. For example, ω2 can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or any range thereof. This is beneficial to further improve the positive electrode capacity and cycle life.

[0100] In some embodiments, based on the total mass of the positive electrode active material and the lithium supplement, the mass percentage of the lithium supplement is ω, 0<ω≤10%. For example, ω can be 0.1%, 0.5%, 1%, 2%, 4%, 6%, 8%, 10% or within the range of any of the above values. In this way, it is beneficial to better balance the capacity and structural stability of the positive electrode.

[0101] In some embodiments, ω is 0<ω≤5%. For example, ω can be 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or any range thereof. In this way, it is beneficial to better balance the capacity and structural stability of the positive electrode.

[0102] In some embodiments, the positive electrode active material includes an iron lithium phosphate active material, which can effectively improve the cycle life of the battery.

[0103] In some embodiments, the lithium iron phosphate active material includes one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0104] In some embodiments, the lithium-ion battery further includes a negative electrode sheet, and the negative electrode sheet and the positive electrode sheet satisfy: 1≤N / P≤1.1, wherein N / P=(negative electrode surface density×negative electrode active material content ratio×negative electrode gram capacity) / (positive electrode surface density×positive electrode active material content ratio×positive electrode gram capacity). In this way, the possibility of lithium precipitation at the negative electrode can be reduced, and the excessive consumption of positive electrode lithium when the negative electrode is excessive can be reduced, so that the battery has a higher capacity and cycle life.

[0105] In some embodiments, 1.01≤N / P≤1.1. Alternatively, 1.03≤N / P≤1.08. In this way, the capacity and cycle life can be further improved.

[0106] It can be understood that the "negative electrode surface density" mentioned in the present application refers to the total surface density of the negative electrode active material layer; the "negative electrode active material content ratio" refers to the mass proportion of the negative electrode active material in the negative electrode active material layer; the "positive electrode surface density" refers to the total surface density of the positive electrode active material layer; the "positive electrode active material content ratio" refers to the mass proportion of the positive electrode active material in the positive electrode active material layer.

[0107] In some embodiments, a preparation method of the lithium supplement of the present application may include the following steps:

[0108] S10, dissolving the lithium supplement material in deionized water, adding a conductive agent and a catalyst, and stirring to obtain a uniform slurry, wherein the concentration of the slurry is 20g / L~100g / L, and the lithium supplement material includes a lithium-containing carbon oxide Li 2 C x O y .

[0109] S20, spray drying the prepared slurry at an inlet air temperature of 150° C. to 250° C. and a creeping feed speed of 20 r / min to 50 r / min to prepare a lithium supplement.

[0110] In some embodiments, the concentration of the slurry can be 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, 100 g / L or within a range consisting of any of the above values.

[0111] It can be understood that the "concentration of the slurry" mentioned in the present application refers to the total concentration of the lithium supplement material, the conductive agent and the catalyst in the slurry.

[0112] When the concentration of the slurry is within this range, the concentration is relatively low. Thus, during the spray drying process, the precipitation rate of the conductive agent is relatively fast, so that part of the conductive agent (which may carry a small amount of catalyst) can be precipitated first and form a core / core aggregate; while the precipitation rate of the lithium supplement material is relatively slow, and it can be precipitated on the already formed core, and together with the subsequently precipitated catalyst and the remaining conductive agent, form an outer shell to prepare the lithium supplement agent of the first aspect of the present application.

[0113] It should be noted that the size of the inner core of the lithium supplement can be regulated by the concentration of the slurry or the inlet air temperature, and can also be regulated by the amount of conductive agent added.

[0114] In some embodiments, the air inlet temperature may be 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C or any range thereof. In this way, the volume average particle size Dv50 of the lithium supplement is adjusted to within the range of the first aspect of the present application.

[0115] In some embodiments, the mass ratio of the lithium supplement material, the conductive agent and the catalyst in the slurry is (40-98.5):(1-40):(0.5-20). For example, the mass ratio can be 40:1:0.5, 98.5:1:0.5, 40:40:0.5, 40:40:20, 98.5:40:0.5, 98.5:40:20, 98.5:1:20 or within the range of any of the above values.

[0116] In a second aspect, the present application provides a lithium supplement, comprising a core and a shell covering at least a portion of the surface of the core (see Figure 1 ), the inner core comprises a second conductive agent, the outer shell comprises a lithium supplement material, a first conductive agent and a catalyst, the lithium supplement material comprises a carbon oxide containing lithium, and the volume average particle size Dv50 of the lithium supplement agent is 2 μm to 10 μm.

[0117] In some embodiments, the lithium supplement is the lithium supplement in the lithium ion battery provided in the first aspect of the present application.

[0118] In a second aspect, the present application provides a positive electrode plate, comprising a positive electrode active material layer, wherein the positive electrode active material layer contains the lithium supplement agent of the second aspect of the present application.

[0119] The lithium supplement agent in the second aspect of the present application or the lithium supplement agent contained in the positive electrode plate in the third aspect has a similar function to that of the lithium supplement agent in the lithium ion battery provided in the first aspect of the present application, and will not be described in detail here.

[0120] In addition, the lithium ion battery and the electric device of the present application will be described below with reference to the drawings as appropriate.

[0121] Generally, lithium-ion batteries include a positive electrode sheet, a negative electrode sheet, an electrolyte, and a separator. During the battery charging and discharging process, active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet. The separator is set between the positive electrode sheet and the negative electrode sheet, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.

[0122] Positive electrode

[0123] In some embodiments, the positive electrode sheet includes a positive current collector and a positive active material layer disposed on at least one surface of the negative current collector.

[0124] As a non-limiting example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode active material layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0125] In some of the 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 polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be obtained by forming a metal material on a polymer material substrate. In the positive electrode current collector, non-limiting examples of the metal material may include one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy. In the positive electrode current collector, non-limiting examples of the polymer material substrate may include one or more of substrates such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.

[0126] In some embodiments, the positive electrode active material may also include one or more of the following materials: lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional 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 may include, but are not limited to, lithium cobalt oxides (such as LiCoO 2 ), lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and modified compounds thereof. Non-limiting examples of lithium cobalt oxide may include LiCoO 2 Non-limiting examples of lithium nickel oxides may include LiNiO 2 Non-limiting examples of lithium manganese oxides may include LiMnO 2 、LiMn 2 O 4 etc.; Non-limiting examples of lithium nickel cobalt manganese oxides may include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 (Also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O 2 (Also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O 2 (Also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O 2(Also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O 2 (Also referred to as NCM 811 ) etc. Non-limiting examples of lithium nickel cobalt aluminum oxide may include LiNi 0.8 Co 0.15 Al 0.05 O 2 .

[0127] It is understandable that the battery will be accompanied by lithium (Li) deintercalation and consumption during the charging and discharging process, and the content of Li in the positive electrode plate is different when the battery is discharged to different states. In the list of positive electrode materials in this application, unless otherwise specified, the content of Li is the initial state of the material. The positive electrode material is applied to the positive electrode plate in the battery system, and after the charge and discharge cycle, the content of Li in the positive electrode material contained in the plate usually changes. Among them, the content of Li can be measured by molar content, but is not limited to this. Regarding "the content of Li is the initial state of the material", the initial state of the material refers to the state before the material is added to the positive electrode slurry. It is understandable that the new material obtained by appropriate modification on the basis of the listed positive electrode materials is also within the scope of the positive electrode material. The aforementioned appropriate modification refers to the acceptable modification method for the positive electrode material, and non-limiting examples include coating modification.

[0128] In the list of positive electrode materials in this application, the content of oxygen (O) is only a theoretical state value. The release of oxygen from the lattice will cause the molar content of oxygen to change, and the actual content of O will fluctuate. Among them, the content of O can be measured by molar content, but is not limited to this.

[0129] In some embodiments, the positive electrode active material layer may further include a binder. As non-limiting examples, the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.

[0130] In some embodiments, the positive electrode active material layer may further optionally include a conductive agent. As a non-limiting example, the conductive agent may include one or more of carbon black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. Among them, the carbon black includes one or more of superconducting carbon, acetylene black, and Ketjen black.

[0131] In some of the embodiments, the positive electrode sheet can be prepared in the following manner: the components for preparing the positive electrode sheet, such as the positive electrode active material, the lithium supplement, the conductive agent, the binder and any other components are dispersed in a solvent to form a positive electrode slurry; the positive electrode slurry is coated on at least one side of the positive electrode collector, and after drying, cold pressing and other processes, the positive electrode sheet can be obtained. The type of solvent can be selected from but not limited to any one of the aforementioned embodiments, such as N-methylpyrrolidone (NMP). The surface of the positive electrode collector coated with the positive electrode slurry can be on a single surface of the positive electrode collector or on both surfaces of the positive electrode collector.

[0132] Negative electrode

[0133] The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode active material layer includes a negative electrode active material.

[0134] As a non-limiting example, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0135] In some of the 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 polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be obtained by forming a metal material on a polymer material substrate. In the negative electrode current collector, non-limiting examples of the metal material may include one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy. In the negative electrode current collector, non-limiting examples of the polymer material substrate may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) and the like.

[0136] In some of the embodiments, the negative electrode active material may adopt the negative electrode active material for batteries known in the art. 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, lithium titanate, etc. The silicon-based material may include one or more of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may include one or more of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional 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.

[0137] In some embodiments, the negative electrode active material layer may further 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).

[0138] In some embodiments, the negative electrode active material layer may further include a conductive agent, which may include one or more of carbon black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0139] In some embodiments, the carbon black includes one or more of superconducting carbon, acetylene black and Ketjen black.

[0140] In some of the embodiments, the negative electrode active material layer may further include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).

[0141] In some embodiments, the negative electrode sheet can be prepared by the following method: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (a non-limiting example of the solvent is deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on at least one side of the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode sheet can be obtained. The surface of the negative electrode current collector coated with the negative electrode slurry can be on a single surface of the negative electrode current collector or on both surfaces of the negative electrode current collector.

[0142] Electrolytes

[0143] The electrolyte has the function of conducting ions between the positive electrode and the negative electrode. The present application has no particular restrictions on the type of electrolyte, which can be selected according to needs. For example, the electrolyte can be liquid, gel or all-solid.

[0144] In some embodiments, the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.

[0145] In some embodiments, the electrolyte salt may include lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ) and lithium hexafluoroarsenate (LiAsF 6 ), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorophosphate (LiPO 2 F 2), one or more of lithium difluorooxalatoborate (LiDFOB), lithium dioxalatoborate (LiBOB), lithium difluorooxalatophosphate (LiDFOP) and lithium tetrafluorooxalatophosphate (LiTFOP).

[0146] In some embodiments, the solvent may include ethylene carbonate (EC, ), propylene carbonate (PC, )、ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate ( ), fluoroethylene carbonate (FEC), methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.

[0147] In some embodiments, the electrolyte may further include additives, such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.

[0148] In some embodiments, the additive in the electrolyte may include, but is not limited to, one or more of fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), trifluoromethylethylene carbonate (TFPC), and the like.

[0149] Isolation film

[0150] In some embodiments, the lithium-ion battery further includes a separator. The present application has no particular limitation on the type of separator, and any known porous separator with good chemical stability and mechanical stability can be selected.

[0151] In some embodiments, the material of the isolation membrane may include one or more of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane may be a single-layer film or a multi-layer composite film, without particular limitation. When the isolation membrane is a multi-layer composite film, the materials of each layer may be the same or different, without particular limitation.

[0152] In some embodiments, the isolation film has a thickness of 6 μm to 40 μm, and may be 12 μm to 20 μm.

[0153] In some of the embodiments, the positive electrode sheet, the negative electrode sheet and the separator can be formed into an electrode assembly by a winding process or a lamination process.

[0154] In some embodiments, the lithium-ion battery may include an outer packaging that can be used to encapsulate the electrode assembly and the electrolyte.

[0155] In some embodiments, the outer packaging of the lithium-ion battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the lithium-ion battery may also be a soft package, such as a bag-type soft package. The material of the soft package may be plastic, and further, non-limiting examples of plastic may include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0156] A lithium-ion battery includes at least one battery cell. A lithium-ion battery may include one or more battery cells.

[0157] In this application, unless otherwise specified, "battery cell" refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy, and further, generally speaking, at least includes a positive electrode sheet, a negative electrode sheet and an electrolyte. During the battery charging and discharging process, active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The electrolyte plays the role of conducting active ions between the positive electrode sheet and the negative electrode sheet.

[0158] The present application has no particular restrictions on the shape of the battery cell, which can be cylindrical, square or any other shape. For example, Figure 2 The battery cell 5 is a square structure as an example.

[0159] In some of these embodiments, reference Figure 3 , the outer packaging may include a shell 51 and a cover plate 53. Among them, the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity. The shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity. The positive electrode sheet, the negative electrode sheet and the isolation membrane can form an electrode assembly 52 through a winding process or a lamination process. The electrode assembly 52 is encapsulated in the receiving cavity. The electrolyte is infiltrated in the electrode assembly 52. ​​The number of electrode assemblies 52 contained in the battery cell 5 can be one or more, and those skilled in the art can select according to actual needs.

[0160] The lithium-ion battery may be a battery module 4 or a battery pack 1 .

[0161] The battery module includes at least one battery cell. The number of battery cells contained in the battery module can be one or more, and those skilled in the art can select a suitable number according to the application and capacity of the battery module.

[0162] Figure 4 4 is an example of a battery module. Figure 4In the battery module 4, the plurality of battery cells 5 may be arranged in sequence along the length direction of the battery module 4. Of course, they may also be arranged in any other manner. Further, the plurality of battery cells 5 may be fixed by fasteners.

[0163] Optionally, the battery module 4 may further include a housing having a receiving space, and the plurality of battery cells 5 are received in the receiving space.

[0164] In some of the embodiments, the battery modules may be assembled into a battery pack. The battery pack may contain one or more battery modules. Those skilled in the art may select a suitable number according to the application and capacity of the battery pack.

[0165] Figure 5 and Figure 6 1 is a battery pack 1 as an example. Figure 5 and Figure 6 The battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box. The battery box includes an upper box body 2 and a lower box body 3. The upper box body 2 can cover the lower box body 3 and form a closed space for accommodating the battery modules 4. The plurality of battery modules 4 can be arranged in the battery box in any manner.

[0166] In addition, the present application also provides an electrical device, which includes the lithium-ion battery provided in the present application. The lithium-ion battery can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device. The electrical device may include mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc., but are not limited to these. Among them, the mobile device may be, for example, a mobile phone, a laptop computer, etc.; the electric vehicle may be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc., but are not limited to these.

[0167] As an electrical device, a lithium-ion battery can be selected according to its usage requirements.

[0168] Figure 7 The power consumption device 6 is taken as an example. The power consumption device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the power consumption device's requirements for high power and high energy density of lithium-ion batteries, a battery pack or a battery module can be used.

[0169] Another example of a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a lithium-ion battery may be used as a power source.

[0170] Below, some embodiments of the present application are described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If the technology or conditions are not specified in the embodiments, the technology or conditions described in the literature in this area or the product instructions are used. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be obtained commercially.

[0171] Example 1

[0172] (1) Preparation of lithium supplements

[0173] The lithium supplement material Li 2 C 2 O 4 Dissolve in deionized water, add conductive agent graphene and catalyst NiO and stir to obtain a uniform slurry, wherein the mass ratio of lithium supplement material, conductive agent and catalyst is 85:11:4, and the concentration of the slurry is 50g / L. The prepared slurry is spray-dried at an inlet air temperature of 200°C and a peristaltic feed speed of 30r / min, and the atomization pressure is 0.38MPa. The dried powder is further dried to obtain a lithium supplement with a core-shell structure, in which the outer shell covers the entire surface of the inner core, the inner core contains graphene, and the outer shell contains Li 2 C 4 O 4 , graphene and NiO.

[0174] (2) Preparation of positive electrode

[0175] The positive electrode active material lithium iron phosphate (LiFePO 4 ), lithium supplement agent, conductive agent carbon black (Super P), binder polyvinylidene fluoride (PVDF) are mixed evenly in a proper amount of solvent N-methylpyrrolidone (NMP) according to a mass ratio of 94:2.8:1:2.2 to obtain a positive electrode slurry; the positive electrode slurry is evenly coated on the double-sided surface of the positive electrode collector aluminum foil, and the positive electrode sheet A is obtained through drying, cold pressing, slitting, cutting and other processes, wherein the coating amount per unit area on both sides is 0.35g / 1540.25mm 2 .

[0176] (3) Preparation of negative electrode sheet

[0177] The negative electrode active material artificial graphite, conductive agent carbon black, binder styrene-butadiene rubber (SBR), and thickener sodium carboxymethyl cellulose (CMC-Na) were dissolved in solvent deionized water at a weight ratio of 96.2:0.8:0.8:1.2, and mixed evenly to prepare a negative electrode slurry; the negative electrode slurry was evenly coated on both sides of the copper foil; the copper foil was dried at room temperature and transferred to a 120°C oven for drying for 1 hour, and then cold pressed and cut to obtain a negative electrode sheet, wherein the coating amount per unit area on both sides was 0.17g / 1540.25mm 2 .

[0178] (4) Isolation film

[0179] A 12μm thick polypropylene isolation film was selected.

[0180] (5) Preparation of electrolyte

[0181] In an argon atmosphere glove box (H 2 O<0.1ppm, O 2 <0.1ppm), the organic solvents ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed evenly in a volume ratio of 3:7, and then LiPF 6 is uniformly dissolved in the above solution to obtain an electrolyte. In the electrolyte, LiPF 6 The concentration is 1 mol / L.

[0182] (6) Preparation of batteries

[0183] The positive electrode sheet A, the separator, and the negative electrode sheet are stacked in order, so that the separator is between the positive and negative electrodes to play an isolating role, and then wound to obtain a bare cell, the tabs are welded to the bare cell, and the bare cell is placed in an aluminum shell, and baked at 80°C to remove water, and then the electrolyte is injected and sealed to obtain an uncharged battery. The uncharged battery then goes through the processes of static, hot and cold pressing, formation, shaping, and capacity testing in turn to obtain battery A. In this battery, the negative electrode sheet and the positive electrode sheet meet the following conditions: N / P=1.07.

[0184] Embodiment 2-4

[0185] The preparation method is similar to that of Example 1, except that in step (1), equal masses of Li 2 CO 3 , Li 2 C 4 O 4 , Li 2 C 3 O 5 Replace Li 2 C 2 O 4 , please see Table 1 for specific differences.

[0186] Embodiment 5~7

[0187] The preparation method is similar to that of Example 1, with the main difference being that in step (1), equal masses of carbon nanotubes, carbon nanodots and carbon black are used to replace graphene. For specific differences, please refer to Table 1.

[0188] Example 8

[0189] The preparation method is similar to that of Example 1, except that in step (1), an equal mass of Co 3 O 4 Replace NiO, see Table 1 for specific differences.

[0190] Embodiments 9 to 11

[0191] The preparation method is similar to that of Example 1, with the main difference being that in step (1), the slurry concentrations are adjusted to 69 g / L, 43 g / L, and 35 g / L, respectively, and the atomization pressures are simultaneously adjusted to 0.4 MPa, 0.35 MPa, and 0.3 MPa, respectively, so that the shell thickness of the prepared lithium supplement is different. For the specific differences, please see Table 1.

[0192] Embodiment 12-15

[0193] The preparation method is similar to that of Example 1, with the main difference being that in step (1), the slurry concentration is adjusted to 32 g / L, 47 g / L, 83 g / L, and 91 g / L, respectively, and the inlet air temperature is simultaneously adjusted to 151° C., 163° C., 205° C., and 232° C., respectively, so that the Dv50 of the lithium supplement and the thickness of the shell of the prepared lithium supplement are changed simultaneously. For specific differences, please see Table 1.

[0194] Embodiments 16 to 21

[0195] The preparation method is similar to that of Example 1, except that in step (1), the mass ratios of the lithium supplement material, the conductive agent and the catalyst are adjusted to 95:1:4, 94:2:4, 92:4:4, 75:21:4, 66:30:4 and 56:40:4, respectively; the slurry concentrations are adjusted to 44.5 g / L, 45 g / L, 46 g / L, 56.5 g / L, 64.5 g / L and 76 g / L, respectively; and the atomization pressures are adjusted to 0.32 MPa, 0.33 MPa, 0.34 MPa, 0.35 MPa, 0.38 MPa and 0.43 MPa, respectively, so that in the prepared lithium supplement, the total mass of the first conductive agent and the second conductive agent accounts for different mass percentages of the lithium supplement. For specific differences, please see Table 1.

[0196] Embodiment 22-25

[0197] The preparation method is similar to that of Example 1, except that in step (1), the mass ratios of the lithium supplement material, the conductive agent and the catalyst are adjusted to 88.5:11:0.5, 88:11:1, 73:11:16 and 70:11:19, respectively; the slurry concentrations are adjusted to 48 g / L, 48.5 g / L, 58 g / L and 61 g / L, respectively; and the atomization pressures are adjusted to 0.36 MPa, 0.37 MPa, 0.39 MPa and 0.4 MPa, respectively, so that the mass percentage ω2 of the catalyst in the prepared lithium supplement is different. For specific differences, please see Table 1.

[0198] Embodiment 26

[0199] The preparation method is similar to that of Example 1, except that in step (1), an equal mass of LiNi 0.8 Co 0.1 Mn 0.1 O 2 Replace LiFePO 4 .

[0200] Embodiment 27

[0201] The preparation method is similar to that of Example 1, except that in step (1), an equal mass of non-conductive material Co is used. 3 O 4 Replace graphene.

[0202] Comparative Example 1

[0203] The preparation method is similar to that of Example 1, except that in step (1), an equal mass of LiF is used instead of Li 2 C 2 O 4 .

[0204] Comparative Example 2

[0205] The preparation method is similar to that of Example 1, except that step (1) is omitted and in step (2), an equal mass of Li 2 C 2 O 4 As a lithium supplement.

[0206] Comparative Example 3

[0207] The preparation method is similar to that of Example 1, except that step (1) is omitted and in step (2), an equal mass of Li 2 C 2 O 4 A mixture of graphene and NiO is used as a lithium supplement, and the mass ratio of the three in the mixture is 85:11:4.

[0208] Comparative Example 4

[0209] The prepared lithium supplement has a hollow structure, which only includes an outer shell, which contains Li 2 C 2 O 4 , graphene and NiO, the preparation process of the lithium supplement is as follows:

[0210] 6 g of oxalic acid is used to prepare a 2 mol / L oxalic acid solution and a 1 mol / L lithium hydroxide solution, 10 L of the oxalic acid solution and 40 L of the lithium hydroxide solution are added to a stirring container at a rate of 2 L / min, and the pH of the reaction system is adjusted to 7 at a stirring speed of 200 r / min, the reaction temperature is 25° C., the reaction time is 12 h, the temperature is lowered to room temperature, and the white precipitate is centrifuged to obtain prepared lithium oxalate particles;

[0211] The prepared lithium oxalate particles, catalyst NiO, and conductive agent graphene (the mass ratio of the three is 85:4:11) are used to prepare a solution with a solid content of 30%. The solution is ground in a nano-grinder at a speed of 1500r / min for 48 hours to obtain a slurry. The prepared slurry is spray-dried at an inlet air temperature of 150°C and a creeping feed rate of 25r / min to obtain a lithium supplement.

[0212] Comparative Example 5

[0213] In the prepared core-shell structure lithium supplement, the core contains graphene and the shell contains Li 2 C 2 O 4 and Co 3 O 4 , the preparation process of the lithium supplement is as follows:

[0214] Co 3 O 4 and Li 2 C 2 O 4 Disperse it into deionized water in a certain proportion, and then add a certain amount of graphene (Li 2 C 2 O 4 , graphene and Co 3 O 4 The mass ratio of the three is 85:11:4), ultrasonic dispersion; rapid freezing with liquid nitrogen, and then placing the obtained sample in a freeze dryer for vacuum drying. After drying, placing it in a tube furnace at 200°C for 2 hours to obtain a lithium supplement.

[0215] Table 1

[0216]

[0217]

[0218] In addition, the lithium supplements and batteries obtained in the above Examples 1 to 27 and Comparative Examples 1 to 5 were subjected to performance tests, and the test results are shown in Table 2 below.

[0219] Test Section

[0220] (1) Decomposition voltage of lithium supplement

[0221] The lithium supplement agent, conductive agent carbon black (Super P), and binder polyvinylidene fluoride (PVDF) in the above embodiments and comparative examples were mixed uniformly in a proper amount of solvent N-methylpyrrolidone (NMP) at a mass ratio of 90:5:5 to obtain a positive electrode slurry; the positive electrode slurry was uniformly coated on both sides of the positive electrode current collector aluminum foil, and a positive electrode sheet B was obtained through drying, cold pressing, striping, cutting and other processes, wherein the coating amount per unit area on both sides was 0.35 g / 1540.25 mm 2 .

[0222] The negative electrode active material artificial graphite, conductive agent carbon black, binder styrene-butadiene rubber (SBR), and thickener sodium carboxymethyl cellulose (CMC-Na) were dissolved in solvent deionized water at a weight ratio of 96.2:0.8:0.8:1.2, and mixed evenly to prepare a negative electrode slurry; the negative electrode slurry was evenly coated on both sides of the copper foil; the copper foil was dried at room temperature and transferred to a 120°C oven for drying for 1 hour, and then cold pressed and cut to obtain a negative electrode sheet, wherein the coating amount per unit area on both sides was 0.17g / 1540.25mm 2 .

[0223] A 12μm thick polypropylene isolation film was selected.

[0224] In an argon atmosphere glove box (H 2 O<0.1ppm, O 2 <0.1ppm), the organic solvents ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed evenly in a volume ratio of 3:7, and then LiPF 6 is uniformly dissolved in the above solution to obtain an electrolyte. In the electrolyte, LiPF 6 The concentration is 1 mol / L.

[0225] The positive electrode sheet B, the separator, and the negative electrode sheet are stacked in order, so that the separator is between the positive and negative electrodes to play an isolating role, and then wound to obtain a bare cell, the tabs are welded to the bare cell, and the bare cell is placed in an aluminum shell, and baked at 80°C to remove water, and then the electrolyte is injected and sealed to obtain an uncharged battery. The uncharged battery then goes through the processes of static, hot and cold pressing, formation, shaping, and capacity testing in sequence to obtain battery B.

[0226] Battery B was charged to 4.5V at a constant current of 0.1C rate, and then left to stand for 5 minutes. The first cycle charging capacity of the battery was recorded at this time. The first cycle charging capacity of the battery was obtained by dividing the first cycle charging capacity of the battery by the mass of the lithium supplement. The decomposition voltage of the lithium supplement is the average charging voltage during the first charging process, that is, decomposition voltage = charging energy at 0.1C rate / first cycle charging capacity at 0.1C rate.

[0227] (2) Diaphragm resistance of the positive electrode

[0228] Connect the red and black test wires of the internal resistance meter to the test wires of the diaphragm resistance meter, turn on the power of the internal resistance meter and pressure display, and connect them to the computer. Then open the air valve, clean the Cu probe, and perform a single-point test under fixed pressure on the positive electrode to test the diaphragm resistance of the electrode. ;in, represents the resistivity of the sample, L represents the length of the sample in the direction of the current, and S represents the cross-sectional area of ​​the sample perpendicular to the direction of the current. The method for obtaining the positive electrode sheet can refer to the above description.

[0229] (3) Cycle life

[0230] At 45°C, charge battery A to 3.65V at 1 / 3C constant current, then charge to 0.05C at 3.65V constant voltage, leave for 5 minutes, and then discharge to 2.5V at 1 / 3C. The obtained capacity is recorded as initial capacity C0. Repeat the above steps for the same battery, and record the discharge capacity Cn of the battery after the nth cycle at the same time. Then, the battery capacity retention rate after each cycle is Pn=Cn / C0×100%, and the battery capacity retention rate is obtained. In this test process, the first cycle corresponds to n=1, the second cycle corresponds to n=2, and ... the 1000th cycle corresponds to n=1000.

[0231] (4) Fast charging performance

[0232] Preparation of Battery C: The preparation of Battery A in Example 1 is similar, except that step (1) is omitted, and in step (2), no lithium supplement is added to the positive electrode slurry, and the positive electrode active material is lithium iron phosphate (LiFePO 4 ), conductive agent carbon black (Super P), and binder polyvinylidene fluoride (PVDF) are in a mass ratio of 96.8:1:2.2.

[0233] Battery A (lithium-supplemented group) and battery C (non-lithium-supplemented group) were charged to 3.65V at a constant current of 3C, left for 5 minutes, and then discharged to 2.5V at a constant current of 1 / 3C and left for 5 minutes. The discharge capacities of battery A and battery C at this time were recorded as a and b respectively. The capacity retention rate = (ab) / b×100%, which can be used to characterize the fast charging performance of the battery.

[0234] (5) Morphology test

[0235] The morphology of the lithium supplement can be observed by performing cross-section polishing tests using a scanning electron microscope (such as ZEISS sigma 300). The test method can be found in the previous description.

[0236] Table 2

[0237]

[0238]

[0239] By comparing the embodiment with the comparative example, it can be seen that the lithium-ion battery provided in the present application has an excellent cycle life, and further, can also take into account fast charging performance.

[0240] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0241] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A lithium ion battery, characterized in that: The invention comprises a positive electrode plate, wherein the positive electrode plate comprises a positive electrode active material layer, and the positive electrode active material layer comprises a positive electrode active material and a lithium supplement; The lithium supplement agent comprises a core and a shell covering at least a portion of the surface of the core, wherein the core comprises a second conductive agent, the shell comprises a lithium supplement material, a first conductive agent and a catalyst, the lithium supplement material comprises a carbon oxide containing lithium, the volume average particle size Dv50 of the lithium supplement agent is 2 μm to 10 μm, and the catalyst comprises a compound X a Y b and / or transition metal elements, wherein X comprises one or more of Ni, Co, Mn, Fe, Cu, Ti, Nb, Mg, Cr, Y comprises one or more of O, C, N, and a and b make the compound X a Y b The algebraic sum of the valences of the elements in is zero.

2. The lithium-ion battery according to claim 1, characterized in that The shell covers the entire surface of the core.

3. The lithium ion battery according to claim 1 or 2, characterized in that: At least a portion of the inner core is embedded in the outer shell.

4. The lithium ion battery according to claim 1 or 2, characterized in that: The thickness d of the shell does not exceed 25% of the volume average particle size Dv50 of the lithium supplement.

5. The lithium ion battery according to claim 1 or 2, characterized in that: The volume average particle size Dv50 of the lithium supplement agent is 3 μm to 8 μm.

6. The lithium ion battery according to claim 1 or 2, characterized in that: The lithium-containing carbon oxide compound satisfies the chemical formula Li2C x O y , 1≤x≤4, 3≤y≤6.

7. The lithium ion battery according to claim 1 or 2, characterized in that: The lithium-containing carbon oxide compound includes one or more of Li2CO3, Li2C2O4, Li2C4O4, Li2C4O6 and Li2C3O5.

8. The lithium ion battery according to claim 1 or 2, characterized in that: The lithium-containing carbon oxide compound includes one or more of Li2CO3, Li2C2O4 and Li2C4O4.

9. The lithium ion battery according to claim 1 or 2, characterized in that: The first conductive agent and the second conductive agent each independently include one or more of a zero-dimensional conductive carbon material, a one-dimensional conductive carbon material, a two-dimensional conductive carbon material, and a three-dimensional conductive carbon material.

10. The lithium ion battery according to claim 1 or 2, characterized in that: The first conductive agent and the second conductive agent each independently include at least one of a one-dimensional conductive carbon material and a two-dimensional conductive carbon material.

11. The lithium ion battery according to claim 1 or 2, characterized in that: The mass percentage of the catalyst to the lithium supplement agent is ω2, 0.5%≤ω2≤20%.

12. The lithium ion battery according to claim 11, characterized in that 1%≤ω2≤10%.

13. The lithium ion battery according to claim 9, characterized in that: At least one of the following conditions is met: (1) The zero-dimensional conductive carbon material comprises carbon nanodots; (2) The one-dimensional conductive carbon material includes one or more of carbon nanotubes, carbon nanowires and carbon nanofibers; (3) The two-dimensional conductive carbon material includes graphene; (4) The three-dimensional conductive carbon material includes carbon black.

14. The lithium ion battery according to claim 1 or 2, characterized in that: The total mass of the first conductive agent and the second conductive agent accounts for a mass percentage of the lithium supplement agent of ω1, 1%≤ω1≤40%.

15. The lithium ion battery according to claim 14, characterized in that: 2%≤ω1≤21%.

16. The lithium ion battery according to claim 1 or 2, characterized in that: Based on the total mass of the positive electrode active material and the lithium replenisher, the mass percentage of the lithium replenisher is ω, 0<ω≤10%.

17. The lithium ion battery according to claim 1 or 2, characterized in that: The positive electrode active material includes an iron lithium phosphate active material.

18. The lithium ion battery according to claim 1 or 2, characterized in that: The lithium-ion battery also includes a negative electrode plate, and the negative electrode plate and the positive electrode plate satisfy the following relationship: 1≤N / P≤1.1, wherein N / P=(negative electrode surface density×negative electrode active material content ratio×negative electrode gram capacity) / (positive electrode surface density×positive electrode active material content ratio×positive electrode gram capacity).

19. A lithium supplement, characterized in that: The invention comprises a core and a shell covering at least a part of the surface of the core, wherein the core comprises a second conductive agent, the shell comprises a lithium supplement material, a first conductive agent and a catalyst, the lithium supplement material comprises a carbon oxide containing lithium, the volume average particle size Dv50 of the lithium supplement agent is 2 μm to 10 μm, and the catalyst comprises a compound X a Y b and / or transition metal elements, wherein X comprises one or more of Ni, Co, Mn, Fe, Cu, Ti, Nb, Mg, Cr, Y comprises one or more of O, C, N, and a and b make the compound X a Y b The algebraic sum of the valences of the elements in is zero.

20. The lithium supplement according to claim 19, characterized in that: The lithium supplement agent in the lithium ion battery according to any one of claims 2 to 18.

21. A positive electrode sheet, characterized in that: The invention comprises a positive electrode active material layer, wherein the positive electrode active material layer contains the lithium supplement agent according to claim 19 or 20.

22. An electrical device, characterized in that: A lithium ion battery comprising any one of claims 1 to 18.

Images