Negative active material and preparation method thereof, negative pole piece, battery and electric device

Abstract

The embodiment of the invention provides a negative active material and a preparation method thereof, a negative pole piece, a battery and an electric device. The negative electrode active material comprises a carbon material and a catalytic material and / or a lithium-loving material attached to the surface of the carbon material, the catalytic material and / or the lithium-loving material comprises a coordination compound A-Dx, and x is greater than or equal to 1 and less than or equal to 6; wherein the element A comprises at least one of a metal element with a catalytic property or a metal element with a lithium-philic property, and the element D comprises at least one of N, S, B, F or O. According to the technical scheme, the fast charging performance of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to a negative electrode active material and a preparation method thereof, a negative electrode plate, a battery and an electrical device. Background Art

[0002] In recent years, lithium-ion batteries have been used in more and more fields, such as wind power, hydropower, thermal power generation and solar power stations, as well as electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace, etc. While lithium-ion batteries have made great progress, higher requirements have been put forward for performance in all aspects.

[0003] Therefore, how to improve the performance of lithium-ion batteries is an urgent problem to be solved. Summary of the invention

[0004] The present application is made in view of the above-mentioned problems, and its purpose is to provide a negative electrode active material and a preparation method thereof, a negative electrode plate, a battery and an electrical device, which can improve the fast charging performance of the battery.

[0005] In a first aspect, a negative electrode active material is provided. The negative electrode active material comprises: a carbon material and a catalytic material and / or a lithium-philic material attached to the surface of the carbon material, wherein the catalytic material and / or the lithium-philic material comprises a coordination compound AD x , 1≤x≤6; wherein the A element includes at least one of a metal element having catalytic properties or a metal element having lithium-philic properties, and the D element includes at least one of N, S, B, F or O.

[0006] In the embodiment of the present application, the negative electrode active material includes a carbon material, a catalytic material and / or a lithium-philic material, and the catalytic material and / or the lithium-philic material includes a coordination compound AD x , catalytic materials and / or lithium-philic materials are attached to the surface of the carbon material. Among them, the coordination compound contains coordination bonds formed by elements A and D, and elements A include at least one of metals with catalytic properties or lithium-philic metals, and elements D include at least one of N, S, B, F or O. Elements A including metals with catalytic properties or lithium-philic metals help to improve the lithium ion transmission rate, and elements D including non-metals can form coordination bonds with elements A, thereby fixing elements A. By making the negative electrode active material include coordination compounds containing coordination bonds formed by metal atoms and non-metal atoms, the transmission of lithium ions and the electron reduction rate can be accelerated, thereby improving the fast charging performance of the battery.

[0007] In one possible embodiment, the metal with catalytic properties includes at least one of Fe, Co, Ni, Cu, Mo, W, Pt, Pd, Rh, Ir or Os; optionally, the metal with catalytic properties includes Mo.

[0008] In the embodiment of the present application, the metal with catalytic properties can reduce the conversion reaction barrier of lithium ions and improve the kinetics. By adding at least one of Fe, Co, Ni, Cu, Mo, W, Pt, Pd, Rh, Ir or Os, especially Mo, to the negative electrode active material, the transmission of lithium ions and the rate of electron reduction can be accelerated, which is beneficial to improving the fast charging performance of the battery.

[0009] In one possible embodiment, the lithium-philic metal element includes at least one of Mg, Sn, Ag, Al, In, Zn, Ca, Sr, Ba, Sc, Y, Rh, Ir, Pd, Pt, Au, Cd, Ga, Ge, Pb, Sb or Bi; optionally, the lithium-philic metal includes at least one of Mg, Zn or Sn.

[0010] In the embodiment of the present application, the lithium-philic metal can provide active sites for the nucleation and deposition of lithium ions and promote the transport of lithium ions. By making the negative electrode active material include at least one of Mg, Sn, Ag, Al, In, Zn, Ca, Sr, Ba, Sc, Y, Rh, Ir, Pd, Pt, Au, Cd, Ga, Ge, Pb, Sb or Bi, especially including Mg, Zn or Sn, it is beneficial to improve the fast charging performance of the battery.

[0011] In a possible implementation manner, the D element includes at least one of N or S.

[0012] In the embodiment of the present application, by making the D element include at least one element of N or S, N and S have better effects and are easy to obtain, which is conducive to wide application in industry.

[0013] In a possible implementation manner, x satisfies: 2≤x≤4.

[0014] In the embodiments of the present application, by keeping the number of coordinated D atoms in the coordination bond between 2 and 4, the coordination compound has a relatively stable structure.

[0015] In a possible implementation, the coordination compound includes at least one of Mg-N4, Mo-N4, Zn-N4, and Sn-N4.

[0016] In the embodiments of the present application, when the negative electrode active material includes at least one of the above coordination compounds, the battery has better performance.

[0017] In a possible implementation, the particle size of the catalytic material and / or the lithium-philic material is less than or equal to 5 nm; optionally, the particle size of the catalytic material and / or the lithium-philic material is less than or equal to 2 nm.

[0018] In the embodiments of the present application, by making the particle size of the catalytic material and / or the lithium-philic material less than or equal to 5 nm, especially not greater than 2 nm, the catalytic material and / or the lithium-philic material can be evenly dispersed in the carbon material and the charging capacity of the battery can be improved, and the production difficulty and production cost can be reduced.

[0019] In a possible implementation, in the negative electrode active material, the mass proportion of the A element is 0.1%-5%; optionally, the mass proportion of the A element is 0.2%-1%.

[0020] In the embodiment of the present application, by making the mass fraction of element A in the negative electrode active material 0.1%-5%, especially 0.2%-1%, the possibility of element A forming large clusters can be reduced, and element A can be evenly dispersed on the carbon material, thereby improving the performance of the battery.

[0021] In a possible implementation, in the negative electrode active material, the mass proportion of the D element is 0.05%-8%; optionally, the mass proportion of the D element is 0.12%-2%.

[0022] In the embodiment of the present application, by making the mass fraction of the D element in the negative electrode active material 0.05%-8%, especially 0.12%-2%, sufficient D element can form a coordination bond with the A element, thereby improving the performance of the battery.

[0023] In a possible implementation, the carbon material includes graphite.

[0024] In the embodiments of the present application, by making the carbon material include graphite, the battery has better performance, and graphite is easy to obtain, which is conducive to application in industry.

[0025] The second aspect of the present application provides a preparation method for preparing the negative electrode active material described in any embodiment of the first aspect. The method comprises: mixing a carbon material, a source A, and a source D in a solvent to obtain a mixed slurry; drying the mixed slurry to obtain a mixed powder; sintering the mixed powder to obtain a negative electrode active material precursor; washing the negative electrode active material precursor with an acidic solution and an alkaline solution in sequence to obtain the negative electrode active material.

[0026] In a possible implementation, the A source includes at least one of chloride salt, nitrate salt, hexafluorophosphate salt, perchlorate salt, and bistrifluoromethanesulfonimide salt of the A element.

[0027] In a possible embodiment, the D source includes at least one of a nitrogen source, a sulfur source, a boron source, a fluorine source, and a phosphorus source; optionally, the nitrogen source includes at least one of melamine, o-phenanthroline, pyrrole, pyridine, urea, and cyanamide; optionally, the sulfur source includes at least one of thiourea, thiophene, and thioacetamide; optionally, the boron source includes at least one of boric acid, boron oxide, and boron trichloride; optionally, the fluorine source includes at least one of polytetrafluoroethylene, ammonium fluoride, and lithium fluoride; optionally, the phosphorus source includes at least one of phosphorus oxychloride, ammonium dihydrogen phosphate, and isopropyl phosphate.

[0028] In a possible implementation manner, the molar ratio of the D element in the D source to the A element in the A source is 1-6.

[0029] The third aspect of the present application provides a negative electrode plate, comprising a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector; the negative electrode film layer comprises the negative electrode active material described in any embodiment of the first aspect of the present application, or the negative electrode active material prepared by the preparation method of the negative electrode active material described in any embodiment of the second aspect of the present application.

[0030] The fourth aspect of the present application provides a battery, comprising the negative electrode plate described in the third aspect of the present application.

[0031] The fifth aspect of the present application provides an electrical device, comprising the battery described in the fourth aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0033] Figure 1 A flow chart of a method for preparing a negative electrode active material according to an embodiment of the present application;

[0034] Figure 2 A schematic diagram of a negative electrode sheet according to an embodiment of the present application;

[0035] Figure 3 A schematic diagram of a battery cell according to an embodiment of the present application;

[0036] Figure 4 A schematic diagram of the structure of a battery cell according to an embodiment of the present application;

[0037] Figure 5 A schematic diagram of a battery according to an embodiment of the present application;

[0038] Figure 6 A schematic diagram of the structure of a battery according to one embodiment of the present application;

[0039] Figure 7 This is a schematic diagram of the structure of an electric device according to one embodiment of the present application;

[0040] Figure 8 This is an XPS graph of the Mo element according to one embodiment of the present application;

[0041] Fig. 9 This is an XPS chart of the N element according to one embodiment of the present application.

[0042] Reference numerals:

[0043] 1-Electrical devices;

[0044] 11-shell, 12-electrode assembly, 13-cover plate;

[0045] 100-battery cell, 121-negative electrode sheet, 123-negative electrode active material, 200-method for preparing negative electrode active material, 400-battery, 401-upper box, 402-lower box, 500-motor, 600-controller;

[0046] 1211 - negative electrode current collector, 1212 - negative electrode film layer. DETAILED DESCRIPTION

[0047] Hereinafter, the negative electrode active material and preparation method thereof, the negative electrode sheet, the battery and the electric device of the present application are described in detail with appropriate reference to the drawings, but unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of actually the same structure may be omitted. In addition, the drawings and the following descriptions 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.

[0048] "Scope" disclosed in the present application is 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 specific range. The scope limited in this way can be including end values ​​or not including end values, and can be arbitrarily combined, that is, any lower limit can form a scope with any upper limit combination. 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 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following scope can be all 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 of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0049] 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.

[0050] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0051] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, and can be performed sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), which 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 may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0052] The terms "above", "below", "greater than" or "less than" as used in this application include the number, for example, "at least one" means one or more, and "at least one of A and B" means "A", "B" or "A and B".

[0053] In the 21st century, mankind is facing two serious problems: energy crisis and environmental pollution. Therefore, the development and research of clean, renewable new energy sources are of far-reaching significance. Among them, various types of automobiles account for about 40% of oil consumption, and 42% of global air pollution comes from emissions from traffic vehicles. Countries around the world attach great importance to electric vehicles, and my country has also listed the development of electric vehicles as an important development direction. The research on power batteries as vehicle power has become the main bottleneck in the development of power vehicles. At present, the main candidates for power batteries are nickel-hydrogen batteries, lithium-ion batteries and fuel cells. Based on cost-effectiveness considerations, lithium-ion batteries have greater advantages. As an energy storage material, lithium-ion batteries have the advantages of high voltage, large specific capacity, long cycle life and good safety performance compared to traditional materials. They are widely used in portable electronic devices, electric vehicles, aerospace and military engineering, and have a wide range of application scenarios and huge economic benefits.

[0054] Carbon materials are widely used in the research of lithium battery systems due to their advantages such as low density, stable and controllable chemical properties. As a member of carbon materials, graphite is widely used as the negative electrode active material of lithium batteries due to its excellent cycle performance and ability to form a stable solid electrolyte interface (SEI) film. However, due to the limitations of lithium battery ion transport and kinetics, high current density will cause carbon materials, especially graphite negative electrode materials, to undergo significant changes, which will lead to uneven distribution of charging current in the negative electrode active material, so that most of the negative electrode active material of the lithium battery negative electrode is not utilized, that is, when carbon materials are used as the negative electrode active material of the battery, the battery's charging capacity is insufficient, and when graphite is used as the negative electrode active material of the battery, this phenomenon is particularly obvious.

[0055] In view of this, the present application provides a negative electrode active material, which includes a carbon material and a catalytic material and / or a lithium-philic material attached to the surface of the carbon material, wherein the catalytic material and / or the lithium-philic material includes a coordination compound AD x ; Wherein, 1≤x≤6, the A element includes at least one of a metal with catalytic properties or a lithium-philic metal, and the D element includes at least one of N, S, B, F or O. By adding a coordination compound including a coordination bond formed by a metal element and a non-metal element to the negative electrode active material, the lithium ion transmission rate and the electron reduction rate can be increased, the fast charging ability of the carbon material can be increased, and the fast charging performance of the battery can be improved.

[0056] The negative electrode active material and preparation method thereof, negative electrode sheet, battery and electric device of the present application are described below with reference to the accompanying drawings.

[0057] The following takes lithium-ion batteries as an example. Lithium-ion batteries are a typical secondary battery. Because they rely on the chemical reaction of lithium ions being embedded and released between the positive and negative electrodes for charging and discharging, lithium-ion batteries are also called rocking-chair batteries. During the charging process of lithium-ion batteries, lithium ions are released from the positive electrode active material, moved to the negative electrode through the conduction of the electrolyte and embedded in the negative electrode active material; and during the discharge process, lithium ions are released from the negative electrode active material, moved to the positive electrode through the conduction of the electrolyte and embedded in the positive electrode active material.

[0058] It should be understood that the "lithium insertion", "embedding" and "embedding" processes described in this application refer to the process in which lithium ions are embedded in the positive electrode active material or the negative electrode active material due to an electrochemical reaction, and the "extraction", "delithium" and "extraction" processes described in this application refer to the process in which lithium ions are extracted from the positive electrode active material or the negative electrode active material due to an electrochemical reaction.

[0059] [Negative electrode active material]

[0060] The first aspect of the present application provides a negative electrode active material, which includes a carbon material and a catalytic material and / or a lithium-philic material attached to the surface of the carbon material, wherein the catalytic material and / or the lithium-philic material includes a coordination compound AD x , 1≤x≤6; wherein the A element includes at least one of a metal element having catalytic properties or a metal element having lithium-philic properties, and the D element includes at least one of N, S, B, F or O.

[0061] Metal elements with catalytic properties have the ability to reduce electrochemical overpotential and improve kinetic conditions. In batteries, the electrolyte is composed of ions and solvents; when ions enter the solution, they need to overcome the attraction of solvent molecules to migrate to the other electrode. This phenomenon is called the desolvation barrier. In lithium-ion batteries, the migration of lithium ions needs to overcome the solvation barrier, and catalyst materials can reduce the barrier to lithium ion desolvation and accelerate the desolvation rate of lithium ions, thereby increasing the transmission rate of lithium ions and improving the fast charging performance of the battery.

[0062] Lithium-philic metal elements are metal elements whose binding energy with lithium is greater than 2.3eV. The binding energy between carbon and lithium is 2.3eV. If the binding energy of other metal elements with lithium is greater than 2.3eV, then the metal element can be called a lithium-philic metal element. In other words, lithium-philic materials are attractive to lithium ions, which can increase the lithium ion transmission rate, thereby increasing the ionic conductivity of lithium ions, and can accelerate the diffusion of lithium ions inside the SEI film, that is, increase the lithium ion transmission rate and electron reduction rate.

[0063] The D element includes at least one of N, S, B, F or O. On the one hand, these non-metallic elements will affect the electronic state of the metal elements, and can form coordination bonds with metal atoms, thereby playing a role in fixing the metal elements; on the other hand, during the sintering process, non-metallic elements can inhibit the growth of particles containing metal elements to reduce the impact of excessively large particles of catalytic materials and / or lithium-philic materials on battery energy density and other aspects. The present application can improve the transmission rate of lithium ions and the fast charging performance of the battery by attaching catalytic materials and / or lithium-philic materials to the surface of carbon materials; on the other hand, by using non-metallic elements to fix metal elements, the particle size of the catalytic material and / or lithium-philic material is reduced, and the catalytic performance or lithium-philic performance of the catalytic material and / or lithium-philic material is further improved, thereby further improving the transmission rate of lithium ions and improving the fast charging performance of the battery.

[0064] Coordination Compound AD x Attached to the surface of carbon material, carbon material acts as a carrier of the compound, so AD x And carbon materials can also be expressed as AD x -C.

[0065] Specifically, the A element includes at least one of metal elements with catalytic properties or metal elements with lithium-philic properties, that is, the A element can be at least one of these metal elements; similarly, the D element includes at least one of N, S, B, F or O, that is, the D element can include at least one of the above elements.

[0066] In the embodiment of the present application, the negative electrode active material includes a carbon material and a catalytic material and / or a lithium-philic material, and the catalytic material and / or the lithium-philic material includes a coordination compound AD x , catalytic materials and / or lithium-philic materials are attached to the surface of the carbon material. Among them, the coordination compound contains coordination bonds formed by elements A and D, and the A element includes at least one of a metal with catalytic properties or a metal with lithium-philic properties, and the D element includes at least one of N, S, B, F or O. The A element including a metal with catalytic properties or a metal with lithium-philic properties helps to improve the lithium ion transmission rate, and the non-metallic D element can form a coordination bond with the A element, thereby fixing the A element. By making the negative electrode active material include a coordination compound containing coordination bonds formed by metal atoms and non-metal atoms, the transmission of lithium ions and the electron reduction rate can be accelerated, thereby improving the fast charging performance of the battery.

[0067] In some embodiments, the metal having catalytic properties includes at least one of Fe, Co, Ni, Cu, Mo, W, Pt, Pd, Rh, Ir or Os; optionally, the metal having catalytic properties includes Mo.

[0068] In the above scheme, the metal with catalytic properties can reduce the conversion reaction barrier of lithium ions and improve the kinetics. By adding at least one of Fe, Co, Ni, Cu, Mo, W, Pt, Pd, Rh, Ir or Os, especially Mo, in the negative electrode active material, the transmission of lithium ions and the electron reduction rate can be accelerated, which is beneficial to improving the fast charging performance of the battery.

[0069] In some embodiments, the lithium-philic metal element includes at least one of Mg, Sn, Ag, Al, In, Zn, Ca, Sr, Ba, Sc, Y, Rh, Ir, Pd, Pt, Au, Cd, Ga, Ge, Pb, Sb or Bi; optionally, the lithium-philic metal includes at least one of Mg, Zn or Sn.

[0070] In the above scheme, the lithium-philic metal can provide active sites for the nucleation and deposition of lithium ions and promote the transport of lithium ions. When at least one of Mg, Sn, Ag, Al, In, Zn, Ca, Sr, Ba, Sc, Y, Rh, Ir, Pd, Pt, Au, Cd, Ga, Ge, Pb, Sb or Bi is included in the negative electrode active material, especially when Mg, Zn or Sn is included, it is beneficial to improve the fast charging performance of the battery.

[0071] In some embodiments, the D element includes at least one of N or S.

[0072] In the above scheme, by making the D element include at least one of N and S, N and S have better effects and are easy to obtain, which is conducive to wide application in industry.

[0073] In a possible implementation manner, x satisfies: 2≤x≤4.

[0074] In the above scheme, by keeping the number of coordination of D atoms in the coordination bond between 2 and 4, the coordination compound has a relatively stable structure.

[0075] In a possible implementation, the coordination compound includes at least one of Mg-N4, Mo-N4, Zn-N4, and Sn-N4.

[0076] In the embodiments of the present application, when the negative electrode active material includes at least one of the above coordination compounds, the battery has better performance.

[0077] In some embodiments, the particle size of the catalytic material and / or the lithiophilic material is less than 5 nm; alternatively, the particle size of the catalytic material and / or the lithiophilic material is less than or equal to 2 nm.

[0078] In the above scheme, by making the particle size of the catalytic material and / or the lithium-philic material less than or equal to 5 nm, especially not greater than 2 nm, the catalytic material and / or the lithium-philic material can be evenly dispersed in the carbon material and the charging capacity of the battery can be improved, and the production difficulty and production cost can be reduced.

[0079] Specifically, the particle size of the catalytic material and / or the lithium-philic material can be 4.8 nm, 4.7 nm, 4.5 nm, 4.2 nm, 3.5 nm, 2.4 nm or any value within the above range.

[0080] In some embodiments, in the negative electrode active material 123 , the mass proportion of the A element is 0.1%-5%; alternatively, the mass proportion of the A element is 0.2%-1%.

[0081] In the above scheme, by making the mass fraction of element A in the negative electrode active material 0.1%-5%, especially 0.2%-1%, the possibility of element A forming large clusters can be reduced, and element A can be evenly dispersed on the carbon material, thereby improving the performance of the battery.

[0082] Specifically, the mass percentage of element A may be 0.1%, 0.2%, 0.5%, 1%, 1.2%, 2.3%, 5% or any value within the above range.

[0083] In some embodiments, in the negative electrode active material 123 , the mass proportion of the D element is 0.05%-8%; alternatively, the mass proportion of the D element is 0.12%-2%.

[0084] In the above scheme, by making the mass fraction of D element in the negative electrode active material 0.05%-8%, especially 0.12%-2%, sufficient D atoms can form coordination bonds with A atoms, thereby improving the performance of the battery.

[0085] Specifically, the mass percentage of the D element can be 0.05, 0.12, 0.2, 0.4%, 0.6%, 1.2%, 2%, 2.3%, 8% or any value within the above range.

[0086] In some embodiments, the carbon material includes graphite.

[0087] In the above scheme, by making the carbon material include graphite, the battery has better performance, and graphite is easy to obtain, which is conducive to application in industry.

[0088] [Method for preparing negative electrode active material]

[0089] The second aspect of the present application provides a method for preparing a negative electrode active material, which is used to prepare the negative electrode active material of any embodiment of the first aspect of the present application. Figure 1Flow chart of a method for preparing a negative electrode active material according to an embodiment of the present application, as shown in FIG. Figure 1 As shown, the method 200 includes:

[0090] 201: mixing the carbon material, the A source, and the D source in a solvent to obtain a mixed slurry;

[0091] 202: drying the mixed slurry to obtain a mixed powder;

[0092] 203: Sintering the mixed powder to obtain a negative electrode active material precursor;

[0093] 204: Wash the negative electrode active material precursor with an acid solution and an alkaline solution in sequence to obtain a negative electrode active material.

[0094] In step 202, the mixed slurry can be subjected to rotary evaporation to obtain a mixed powder. However, the mixed slurry can also be subjected to other drying methods to obtain a mixed powder, which is not limited in the present application. Specifically, rotary evaporation is an operation of performing reduced pressure distillation using a rotary evaporator.

[0095] In step 203, the sintering treatment may be carried out in an inert gas atmosphere, heating to a certain temperature at a certain heating rate and keeping the temperature for a period of time to obtain a precursor of the negative electrode active material;

[0096] In some embodiments, the heating rate may be 5° C. / min-15° C. / min, the holding temperature may be 650° C.-700° C., and the holding time may be 1.5 h-3 h.

[0097] In some embodiments, the heating rate is 5° C., the holding temperature is 650° C., and the holding time is 2 h.

[0098] In step 204, the negative electrode active material precursor is washed with an acidic solution and an alkaline solution in sequence, which may be washed in a 1.5M-3M hydrochloric acid solution for 4h-7h and then dried, and then washed in a 0.8M-1.5M sodium hydroxide solution for 4h-6h and then dried to obtain a negative electrode active material.

[0099] In some embodiments, the negative electrode active material may be first washed in a 2M hydrochloric acid solution for 5 hours and then washed in a 1M sodium hydroxide solution for 5 hours to obtain the negative electrode active material.

[0100] The above mixed powder processing, sintering and cleaning processes are only examples, and the specific experimental process needs to be changed according to the changes in raw materials.

[0101] In some embodiments, the source of A includes at least one of a chloride salt, a nitrate salt, a hexafluorophosphate salt, a perchlorate salt, and a bistrifluoromethanesulfonimide salt of A.

[0102] The A element includes at least one of a metal having catalytic properties or a metal having a lithium affinity. The chloride salt containing the A element is a salt containing the above metal element and chlorine, the nitrate containing the A element is a salt containing the above metal element and nitrate, and the hexafluorophosphate, perchlorate, bistrifluoromethanesulfonimide salt containing the A element are deduced by analogy.

[0103] Specifically, when the A element is molybdenum, the A source may be molybdenum pentachloride, molybdenum nitrate, etc.; when the A element is iron, the A source may be ferric chloride, iron nitrate, etc. When the A element is a different element, the same applies.

[0104] The D source includes at least one of a nitrogen source, a sulfur source, a boron source, a fluorine source, and a phosphorus source;

[0105] Optionally, the nitrogen source includes at least one of melamine, o-phenanthroline, pyrrole, pyridine, urea, and cyanamide;

[0106] Optionally, the sulfur source includes at least one of thiourea, thiophene, and thioacetamide;

[0107] Optionally, the boron source includes at least one of boric acid, boron oxide, and boron trichloride;

[0108] Optionally, the fluorine source includes at least one of polytetrafluoroethylene, ammonium fluoride, and lithium fluoride;

[0109] Optionally, the phosphorus source includes at least one of phosphorus oxychloride, ammonium dihydrogen phosphate, and isopropyl phosphate.

[0110] In some embodiments, the molar ratio of the D element in the D source to the A element in the A source is 1-6.

[0111] Specifically, the molar ratio of the D element in the D source to the A element in the A source can be 1, 2, 3, 5, 6 or any value within the above range.

[0112] [Negative electrode]

[0113] Figure 2 Schematic diagram of a negative electrode sheet according to an embodiment of the present application. Figure 2 As shown, the negative electrode plate 121 includes a negative electrode current collector 1211 and a negative electrode film layer 1212 arranged on at least one surface of the negative electrode current collector 1211, and the negative electrode film layer 1212 includes the negative electrode active material described in any embodiment of the first aspect above or the negative electrode active material prepared by the preparation method 200 of the negative electrode active material described in any embodiment of the second aspect above.

[0114] Typically, a battery cell includes a negative electrode sheet 121, a separator, a positive electrode sheet, and an electrolyte. During the battery charge and discharge process, active ions are embedded and released back and forth between the positive and negative electrodes. The electrolyte plays a role in transferring ions between the positive and negative electrodes. The separator is arranged between the positive and negative electrodes, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.

[0115] It should be noted here that the “positive electrode sheet” and “negative electrode sheet” mentioned in the embodiments of the present application refer to the positive electrode sheet and the negative electrode sheet as a whole including active materials, current collectors or other additives.

[0116] As an example, the negative electrode current collector 1211 has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer 1212 is disposed on any one or both of the two opposite surfaces of the negative electrode current collector 1211 .

[0117] In some embodiments, the negative electrode current collector 1211 may be a metal foil or a composite current collector. For example, as the metal foil, a copper foil may be used. 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 formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0118] In some embodiments, the negative electrode film layer 1212 may further include a binder. The binder may be selected from at least one 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).

[0119] In some embodiments, the negative electrode film layer 1212 may further include a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0120] In some embodiments, the negative electrode film layer 1212 may further include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).

[0121] In some embodiments, the negative electrode sheet 121 can be prepared in the following manner: the components for preparing the negative electrode sheet 121, such as the negative electrode active material, the conductive agent, the binder and any other components, are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode collector 1211, and after drying, cold pressing and other processes, the negative electrode sheet 121 can be obtained.

[0122] [Positive electrode]

[0123] The positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.

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

[0125] In some embodiments, the positive electrode active material includes Li x (Ni a Co b Mn c ) 1-d M d O 2-y A y , wherein M includes at least one of Zr, Al, B, Ta, Mo, W, Nb, Sb, and La, A includes at least one of S, N, P, F, Cl, Br, or I, 0.2<x≤1.2, 0.5≤a<1.0, 0≤b<0.5, 0≤c<1, 0≤d<1, and 0≤y<0.02.

[0126] It should be noted here that the positive electrode active materials include but are not limited to the following substances: Li 0.5 Ni 0.5 Co 0.1 Mn 0.4 O2、Li 0.5 (Ni 0.5 Co 0.1 Mn 0.4 ) 0.5 Zr 0.5 O 1.9 S 0.1 、LiNi 0.4 Co 0.3 Mn 0.3 O2.

[0127] It should be noted that in the positive electrode sheet, battery or electrical device, lithium ions will be consumed as the battery goes through the formation and circulation processes, so the lithium content in the positive electrode active material measured will be less than 1. At the same time, if the positive electrode sheet is supplemented with lithium, the lithium content in the positive electrode active material measured will be greater than 1 after the battery goes through the formation and circulation processes.

[0128] Similarly, in the list of positive electrode materials in this application, the molar content of O is only a theoretical value. The release of oxygen from the lattice will cause the molar content of oxygen to change, and the actual molar content of O will fluctuate.

[0129] 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 polymer material base and a metal layer formed on at least one surface of the polymer material base. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0130] In some embodiments, the positive electrode active material may also adopt positive electrode active materials for batteries that are well known in the art. As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates with an olivine structure, 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. Among them, examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM622), LiNi0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.1 Al 0.05 O2) and its modified compounds, etc. Examples of lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0131] In some embodiments, the positive electrode film layer may further optionally include a binder. As an example, the positive electrode binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.

[0132] In some embodiments, the positive electrode film layer may further include a conductive agent, which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0133] In some 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 conductive agent, the positive electrode binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry, and the positive electrode slurry is coated on the positive electrode collector. After drying, cold pressing and other processes, the positive electrode sheet can be obtained.

[0134] [Electrolytes]

[0135] The electrolyte plays a role in conducting ions between the negative electrode plate 121 and the negative electrode plate. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. For example, the electrolyte can be liquid, gel or all-solid.

[0136] In some embodiments, the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.

[0137] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0138] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane sulfone, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.

[0139] In some embodiments, the electrolyte may further include electrolyte 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.

[0140] [Isolation film]

[0141] In some embodiments, the battery cell 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.

[0142] In some embodiments, the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane can 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 can be the same or different, without particular limitation.

[0143] In some embodiments, the negative electrode sheet 121 , the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.

[0144] In some embodiments, the battery cell may include an outer packaging, which may be used to encapsulate the electrode assembly and the electrolyte.

[0145] In some embodiments, the outer packaging of the battery cell may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc. The outer packaging of the battery cell may also be a soft package, such as a bag-type soft package. The material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0146] The present application has no particular limitation on the shape of the battery cell, which may be cylindrical, square or any other shape. Figure 3 It is a schematic diagram of a battery cell according to an embodiment of the present application.

[0147] Figure 4 FIG. 1 is a schematic diagram of the structure of a battery cell according to an embodiment of the present application. Figure 4As shown, the outer packaging of the battery cell 100 includes a shell 11 and a cover plate 13. Among them, the shell 11 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 11 has an opening connected to the receiving cavity, and the cover plate 13 can be covered on the opening to close the receiving cavity. The negative electrode sheet 121 and the positive electrode sheet can be formed into an electrode assembly 12 through a winding process or a lamination process. The electrode assembly 12 is encapsulated in the receiving cavity. The electrolyte is infiltrated in the electrode assembly 12. The number of electrode assemblies 12 contained in the battery cell 100 can be one or more, and those skilled in the art can select according to specific actual needs.

[0148] In some embodiments, the battery cells 100 may also be assembled into a battery module. The battery module may contain one or more battery cells 100. The specific number may be selected by those skilled in the art according to the application and capacity of the battery module.

[0149] Figure 5 is a schematic diagram of a battery according to one embodiment of the present application, Figure 6 This is a schematic diagram of the structure of a battery according to one embodiment of the present application. Figure 5 and Figure 6 The battery 400 may include a battery box and a plurality of battery cells 100 disposed in the battery box. The battery box includes an upper box body 401 and a lower box body 402. The upper box body 401 can cover the lower box body 402 and form a closed space for accommodating the battery cells 100. The plurality of battery cells 100 may be arranged in the battery box in any manner.

[0150] In addition, the present application also provides an electric device, which includes at least one of the negative electrode plate 121, battery cell 100 or battery 400 provided in the present application. The negative electrode plate 121, battery cell 100 or battery 400 can be used as a power source for the electric device, and can also be used as an energy storage unit for the electric device. The electric device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto.

[0151] For example, Figure 7 Schematic diagram of the structure of an electric device according to an embodiment of the present application. Figure 7As shown, the electrical device is a vehicle 1, and the vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A motor 500, a controller 600 and a battery 400 may be arranged inside the vehicle 1, and the controller 600 is used to control the battery 400 to supply power to the motor 500. For example, a battery 400 may be arranged at the bottom, front or rear of the vehicle 1. The battery 400 may be used to power the vehicle 1, for example, the battery 400 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery 400 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0152] As the electrical device, the negative electrode active material 123, the negative electrode plate 121, the battery cell 100 or the battery 400 may be selected according to the usage requirements.

[0153] The electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the electric device's requirements for high power and high energy density of the battery, a battery cell 100 or a battery 400 may be used.

[0154] As another example, the device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be light and thin, and the battery cell 100 may be used as a power source.

[0155] [Example]

[0156] Hereinafter, the embodiments of the present application will be 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 no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0157] [Example 1]

[0158] 1). Preparation of lithium-ion batteries

[0159] 1.11). Preparation of negative electrode active material: Add carbon material graphite, source A molybdenum pentachloride, and source D o-phenanthroline in a mass ratio of 20g:0.8g:1.3g to 200ml of methanol solution to obtain a mixed slurry, stir for 6 hours and then rotary evaporate to obtain a mixed powder. Place the mixed powder in a tubular furnace, introduce inert gas Ar gas, heat to 650℃ at a heating rate of 5℃ / min and keep warm for 2h, then cool naturally to obtain a negative electrode active material precursor; wash the obtained negative electrode active material precursor with 2MHCl acid for 5h and dry it, wash it with 1M NaOH for 5h and dry it to obtain the final product, the negative electrode active material.

[0160] 1.12) Preparation of negative electrode sheets: The negative electrode active material, conductive agent super P, sodium carboxymethyl cellulose (CMC-Na), and styrene-butadiene rubber (SBR) are mixed in a proper amount of deionized water solvent system at a weight ratio of 96%:1%:1%:2% to obtain the negative electrode active material. The negative electrode active material is coated on Cu foil, and then dried, cold pressed, and cut to obtain the negative electrode sheet.

[0161] 1.2) Preparation of positive electrode sheets: The positive electrode active material lithium iron phosphate (LiFePO4), the conductive agent carbon nanotube (CNT), and the positive electrode binder polyvinylidene fluoride (PVDF) are dissolved in a solvent N-methylpyrrolidone (NMP) at a weight ratio of 96%:2%:2%, and the positive electrode active material is prepared after being fully stirred and mixed. The positive electrode active material is coated on Al foil, and then dried, cold pressed, and cut to obtain a positive electrode sheet.

[0162] 1.3). Preparation of diaphragm: PE porous polymer film is used as the isolation membrane.

[0163] 1.4) Electrolyte: Dissolve EC / EMC / DMC in 1M LiPF6 at a volume ratio of 1:1:1 and stir evenly to obtain 1 mol / L LiPF6 electrolyte.

[0164] 1.5) Assembly: stack the positive electrode sheet, separator, and negative electrode sheet in order, add a lithium reference electrode between the negative electrode sheet and the separator, and the separator is in the middle of the positive and negative electrodes to play a role of isolation. Wind the electrode assembly and add electrolyte. Then go through the formation, static and other processes to get a lithium-ion battery.

[0165] [Example 2]

[0166] The preparation of the lithium ion battery of Example 2 is basically the same as that of Example 1, except that the negative electrode active material in Example 2 is prepared as follows: carbon material graphite, A source cobalt chloride, and D source o-phenanthroline are added in a mass ratio of 20g:0.8g:2.2g to 200ml of methanol solution to obtain a mixed slurry.

[0167] [Example 3]

[0168] The preparation of the lithium ion battery of Example 3 is basically the same as that of Example 1, except that the negative electrode active material in Example 3 is prepared as follows: carbon material graphite, A source magnesium chloride, and D source o-phenanthroline are added in a mass ratio of 20g:1g:4.7g to 200ml of methanol solution to obtain a mixed slurry.

[0169] [Example 4]

[0170] The preparation of the lithium ion battery of Example 4 is basically the same as that of Example 1, except that the negative electrode active material in Example 4 is prepared as follows: carbon material graphite, A source zinc chloride, and D source o-phenanthroline are added in a mass ratio of 20g:0.6g:2g to 200ml of methanol solution to obtain a mixed slurry.

[0171] [Example 5]

[0172] The preparation of the lithium ion battery of Example 5 is basically the same as that of Example 1, except that the negative electrode active material in Example 5 is prepared as follows: carbon material graphite, A source stannous chloride, and D source o-phenanthroline are added in a mass ratio of 20g:0.5g:1.2g to 200ml of methanol solution to obtain a mixed slurry.

[0173] [Example 6]

[0174] The preparation of the lithium-ion battery of Example 6 is basically the same as that of Example 1, except that the negative electrode active material in Example 6 is prepared as follows: carbon material graphite, source A antimony trichloride, and source D phenanthroline are added to 200 ml of methanol solution in a mass ratio of 20 g:0.5 g:1 g to obtain a mixed slurry.

[0175] [Example 7]

[0176] The preparation of the lithium-ion battery of Example 7 is basically the same as that of Example 1, except that the negative electrode active material in Example 7 is prepared as follows: carbon material graphite, A source molybdenum pentachloride, and D source thiophene are added to 200 ml of methanol solution in a mass ratio of 20 g: 0.8 g: 1.7 g to obtain a mixed slurry.

[0177] [Example 8]

[0178] The preparation of the lithium-ion battery of Example 8 is basically the same as that of Example 1, except that the negative electrode active material in Example 8 is prepared as follows: carbon material graphite, source A molybdenum pentachloride, and source D ammonium fluoride are added to 200 ml of methanol solution in a mass ratio of 20 g: 0.8 g: 0.8 g to obtain a mixed slurry.

[0179] [Example 9]

[0180] The preparation of the lithium ion battery of Example 9 is basically the same as that of Example 1, except that the negative electrode active material in Example 9 is prepared as follows: carbon material graphite, source A molybdenum pentachloride, and source D o-phenanthroline are added in a mass ratio of 20g:0.8g:0.6g to 200ml of methanol solution to obtain a mixed slurry.

[0181] [Example 10]

[0182] The preparation of the lithium ion battery of Example 10 is basically the same as that of Example 1, except that the negative electrode active material in Example 10 is prepared as follows: carbon material graphite, source A molybdenum pentachloride, and source D phenanthroline are added to 200 ml of methanol solution in a mass ratio of 20 g: 0.8 g: 0.8 g to obtain a mixed slurry.

[0183] [Example 11]

[0184] The preparation of the lithium ion battery of Example 11 is basically the same as that of Example 1, except that the negative electrode active material in Example 11 is prepared as follows: carbon material graphite, source A molybdenum pentachloride, and source D o-phenanthroline are added in a mass ratio of 20g:0.08g:0.13g to 200ml of methanol solution to obtain a mixed slurry.

[0185] [Example 12]

[0186] The preparation of the lithium-ion battery of Example 12 is basically the same as that of Example 1, except that the negative electrode active material in Example 12 is prepared as follows: carbon material graphite, source A molybdenum pentachloride, and source D o-phenanthroline are added in a mass ratio of 20g:4g:6.5g to 200ml of methanol solution to obtain a mixed slurry.

[0187] [Example 13]

[0188] The preparation of the lithium-ion battery of Example 13 is basically the same as that of Example 1, except that the negative electrode active material in Example 13 is prepared as follows: carbon material graphite, source A molybdenum pentachloride, and source D phenanthroline are added in a mass ratio of 20g:0.16g:0.26g to 200ml of methanol solution to obtain a mixed slurry.

[0189] [Comparative Example 1]

[0190] The preparation of the lithium ion battery of Comparative Example 1 is substantially the same as that of Example 1, except that the negative electrode active material in Comparative Example 1 is only graphite.

[0191] [Comparative Example 2]

[0192] The preparation of the lithium ion battery of Comparative Example 2 is basically the same as that of Example 1, except that the negative electrode active material in Comparative Example 2 is prepared as follows: carbon material graphite and source molybdenum pentachloride A are added to 200 ml of methanol solution in a mass ratio of 20 g:1.3 g to obtain a mixed slurry.

[0193] [Comparative Example 3]

[0194] The preparation of the lithium ion battery of Comparative Example 3 is basically the same as that of Example 1, except that the negative electrode active material in Comparative Example 3 is prepared as follows: carbon material graphite and D source diammonium phosphate are added to 200 ml of methanol solution in a mass ratio of 20 g:1.3 g to obtain a mixed slurry.

[0195] [Comparative Example 4]

[0196] The preparation of the lithium ion battery of Comparative Example 4 is basically the same as that of Example 1, except that the negative electrode active material in Comparative Example 4 is prepared as follows: carbon material graphite, source A manganese chloride, and source D ammonium dihydrogen phosphate are added to 200 ml of methanol solution in a mass ratio of 20 g: 0.6 g: 2.2 g to obtain a mixed slurry.

[0197] 2). Physical characterization

[0198] 2.1) Detection of coordination compounds: The negative electrode active materials prepared in Examples 1-13 and Comparative Examples 1-4 were subjected to XPS (X-ray photoelectron spectroscopy) testing. The testing conditions were as follows: 20-30 mg of negative electrode active material sample was weighed and the electron escape depth was 3 nm.

[0199] Take the coordination compound Mo-N4 in Example 1 as an example to illustrate, Figure 8 is the XPS diagram of Mo element, Fig. 9 is the XPS graph of N element. Figure 8 As shown in Figure 1, the binding energy of 0-valent Mo is 228 eV, and the binding energy of 4-valent Mo is 229.5 eV. In the XPS image of the Mo element, the binding energy of Mo is between 0-valent Mo and 4-valent Mo and deviates toward the high-valent Mo, proving that Mo has coordination; Fig. 9 As shown, there is a coordination peak between N and metal at 399 eV, proving that N forms a coordination; based on the comparison of the integrated peak areas, it is calculated that a Mo-N4 coordination compound is formed.

[0200] 2.2) Particle size measurement of catalytic materials and / or lithium-philic materials: directly observe and measure using a scanning electron microscope (SEM).

[0201] 2.3) Measurement of the loading amount of element A or element D: Through X-ray photoelectron spectroscopy (XPS) testing, the peaks of different elements are integrated and calculated to obtain the atomic ratio of different elements. The mass fraction or mass ratio can be calculated based on the atomic weight of each element.

[0202] Table 1 Experimental parameters of Examples 1-13 and Comparative Examples 1-4

[0203]

[0204] 3. Battery performance test

[0205] Charging time test: At 25°C, charge the formed battery to 3.6V at a constant current of 0.33C, and charge at a constant voltage of 3.6V until the current is less than 0.05C. After standing, discharge at 0.33C to 2.5V, and measure the initial capacity C0. Then charge to 3.6V at a current of 0.1C, and monitor the potential of the negative electrode by connecting the reference electrode to the negative electrode. When the potential of the negative electrode reaches 0mV, even if it does not reach the upper limit voltage of 3.6V, stand for a while, and then discharge at 0.33C to 2.5V, and record the charging capacity C before standing. x Then, the charging capacity at different rates (0.2C, 0.5C, 1C, 2C, 3C, 5C) was measured according to the same process.

[0206] Based on the capacity C at different rates x The ratio of C0 to C0 can be used to obtain the upper limit SOC of different charging rates. Then, a graph is drawn with SOC as the horizontal axis and the rate as the vertical axis. After fitting, the upper limit charging rate R for every 10% SOC can be obtained. x , based on the upper limit charge rate R per 10% SOC x , according to each charging time = 1 / R x ×60×0.1, and the charging time is obtained by adding them up. For the test results of charging time, please refer to Table 2.

[0207] Table 2 Performance tests of Examples 1-13 and Comparative Examples 1-4

[0208]

[0209]

[0210] The embodiment of the present application uses charging time to measure the fast charging performance of the battery. When the charging time of the battery is shorter, it means that the fast charging performance of the battery is better.

[0211] According to Examples 1-13 and Comparative Examples 1-4, catalytic materials and / or lithium-philic materials are attached to the negative electrode active material, and the catalytic materials and / or lithium-philic materials include a coordination compound formed by element A and element D, and element A includes at least one of metal elements with catalytic properties or metal elements with lithium-philic properties, and element D is at least one of N, S, B, F or O, which can shorten the charging time of the battery and improve the fast charging performance of the battery.

Claims

1. A negative electrode active material, characterized in that: include: A carbon material and a catalytic material and / or a lithium-philic material attached to the surface of the carbon material, wherein the catalytic material and / or the lithium-philic material comprises a coordination compound AD x , 1≤x≤6; The A element includes at least one of a metal element with catalytic properties or a metal element with lithium affinity, and the D element includes at least one of N, S, B, F or O.

2. The negative electrode active material according to claim 1, characterized in that The metal element with catalytic properties includes at least one of Fe, Co, Ni, Cu, Mo, W, Pt, Pd, Rh, Ir or Os; optionally, the metal element with catalytic properties includes Mo.

3. The negative electrode active material according to claim 1 or 2, characterized in that: The lithium-philic metal element includes at least one of Mg, Sn, Ag, Al, In, Zn, Ca, Sr, Ba, Sc, Y, Rh, Ir, Pd, Pt, Au, Cd, Ga, Ge, Pb, Sb or Bi; optionally, the lithium-philic metal element includes at least one of Mg, Zn or Sn.

4. The negative electrode active material according to any one of claims 1 to 3, characterized in that The D element includes at least one of N and S.

5. The negative electrode active material according to any one of claims 1 to 4, characterized in that The x satisfies: 2≤x≤4.

6. The negative electrode active material according to any one of claims 1 to 5, characterized in that The coordination compound includes at least one of Mg-N4, Mo-N4, Zn-N4, and Sn-N4.

7. The negative electrode active material according to any one of claims 1 to 6, characterized in that The particle size of the catalytic material and / or the lithium-philic material is less than or equal to 5 nm; optionally, the particle size of the catalytic material and / or the lithium-philic material is less than or equal to 2 nm.

8. The negative electrode active material according to any one of claims 1 to 7, characterized in that In the negative electrode active material, the mass proportion of the A element is 0.1%-5%; optionally, the mass proportion of the A element is 0.2%-1%.

9. The negative electrode active material according to any one of claims 1 to 8, characterized in that In the negative electrode active material, the mass proportion of the D element is 0.05%-8%; optionally, the mass proportion of the D element is 0.12%-2%.

10. The negative electrode active material according to any one of claims 1 to 9, characterized in that The carbon material includes graphite.

11. A method for preparing the negative electrode active material according to any one of claims 1 to 10, characterized in that: The method comprises: Mixing the carbon material, source A and source D in a solvent to obtain a mixed slurry; Drying the mixed slurry to obtain mixed powder; The mixed powder is sintered to obtain a negative electrode active material precursor; The negative electrode active material precursor is washed with an acidic solution to obtain the negative electrode active material.

12. The method according to claim 11, characterized in that The A source includes at least one of chloride salt, nitrate salt, hexafluorophosphate salt, perchlorate salt or bis(trifluoromethanesulfonyl)imide salt of the A element.

13. The method according to claim 11 or 12, characterized in that: The D source includes at least one of a nitrogen source, a sulfur source, a boron source, a fluorine source or a phosphorus source; Optionally, the nitrogen source includes at least one of melamine, o-phenanthroline, pyrrole, pyridine, urea or cyanamide; Optionally, the sulfur source includes at least one of thiourea, thiophene or thioacetamide; Optionally, the boron source includes at least one of boric acid, boron oxide or boron trichloride; Optionally, the fluorine source includes at least one of polytetrafluoroethylene, ammonium fluoride or lithium fluoride; Optionally, the phosphorus source includes at least one of phosphorus oxychloride, ammonium dihydrogen phosphate or isopropyl phosphate.

14. The method according to any one of claims 11 to 13, characterized in that The molar ratio of the D element in the D source to the A element in the A source is 1-6.

15. A negative electrode plate, characterized in that: It includes a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector; The negative electrode film layer comprises the negative electrode active material according to any one of claims 1 to 10, or the negative electrode active material prepared by the method for preparing a negative electrode active material according to any one of claims 11 or 14.

16. A battery, characterized in that: Includes the negative electrode sheet as described in claim 15.

17. An electrical device, characterized in that: Comprising the battery as claimed in claim 16.

Images