Active material of a positive electrode, positive electrode plate, secondary battery and electrical device

Abstract

Active material of a positive electrode, characterized in that the active material of a positive electrode has the following general formula: Li a Ni x M1 y Mn z M2 1-x-y-z O2, where M1 and M2 each independently contain one or more of the following elements: Co, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb, 0.8≤a≤1.2, 0.55≤x<1, 0 <y≤0,25 und 0≤z≤0,2; The active material of a positive electrode is in the form of secondary particles formed by the aggregation of primary particles, the secondary particles comprising secondary pores formed by the spaces between the primary particles, and the inner diameter of the secondary pores being 0.1 µm to 2 µm.

Description

CROSS-REFERENCES

[0001] The present application incorporates Chinese patent application No. 202310473119.X dated April 27, 2023, entitled “Active material of a positive electrode, manufacturing process, positive electrode plate, secondary battery and electrical device”, which is hereby incorporated in its entirety by reference. AREA OF INVENTION

[0002] This application relates to secondary battery technology, in particular an active material for a positive electrode, a manufacturing process, a positive electrode plate, a secondary battery and an electrical device. STATE OF THE ART

[0003] In recent years, secondary batteries have been widely used in energy storage systems such as hydroelectric, thermal, wind and solar power plants, as well as in numerous fields such as power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment and aerospace.

[0004] The performance of the active material in a positive electrode directly influences the performance of the secondary battery. Currently, active materials for positive electrodes exhibit numerous shortcomings and cannot meet the application requirements of the next generation of electrochemical systems. REVELATION OF THE INVENTION

[0005] This application is made in view of the aforementioned problems and aims to provide an active material for a positive electrode whose secondary particles have secondary pores formed by the spaces between the primary particles and whose inner diameter is 0.1 µm to 2 µm, which contributes to improving the cycle stability of the battery.

[0006] A first aspect of this application concerns an active material of a positive electrode with the following general formula: Li a Ni x M1 y Mn z M2 1-x-y-z O2, where M1 and M2 each independently contain one or more of the following elements: Co, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb, 0.8≤a≤1.2, 0.55≤x<1, 0 <y≤0,25 und 0≤z≤0,2; The active material of a positive electrode is in the form of secondary particles formed by the aggregation of primary particles, the secondary particles comprising secondary pores formed by the spaces between the primary particles, and the inner diameter of the secondary pores being 0.1 µm to 2 µm.

[0007] On the one hand, the secondary particles comprise secondary pores formed by the spaces between primary particles, giving the active material of a positive electrode three-dimensional pore channels. This shortens the solid-state diffusion path of lithium ions and improves battery performance. On the other hand, the presence of secondary pores allows for the exposure of more (010) crystal planes, resulting in more reactive sites and increasing the gravimetric capacity and energy density of the material. Furthermore, the presence of secondary pores can also buffer the volume changes of the active material of a positive electrode during charging and discharging, thereby stabilizing the structure and improving cycle stability.At the same time, by controlling the inner diameter of the secondary pores to 0.1 µm to 2 µm, the energy density and cycle stability of the battery can be significantly increased, thus comprehensively improving battery performance.

[0008] In each embodiment, the ratio of the shortest distance between the secondary pore and the surface of the secondary particle to the Dv50 of the secondary particle is 1 / 5 to 3 / 5, optionally 3 / 10 to 1 / 2.

[0009] Controlling the ratio of the shortest distance between the secondary pores and the surface of the secondary particles to the Dv50 of the secondary particles within a suitable range makes it possible both to increase the performance of the battery and to reduce the influence of the pores on the structure of the active material of a positive electrode.

[0010] In each embodiment, at least some of the primary particles further have primary pores with an inner diameter of 0.05 µm to 0.6 µm, optionally 0.08 µm to 0.2 µm.

[0011] The presence of primary pores helps to further shorten the solid-state diffusion path of lithium ions and improve battery performance. Controlling the inner diameter of the primary pores within a suitable range allows for a balanced consideration of the battery's performance and energy density.

[0012] In each embodiment, the following applies: 0.8 ≤ a ≤ 1.2, 0.8 ≤ x < 1.0, 0 <y≤0,1, 0≤z≤0,1, optional 0,8≤a≤1,2, 0,85≤x≤0,96, 0<y≤0,02, 0≤z≤0,05.

[0013] In each embodiment, the inner diameter of the secondary pores is 0.2 µm to 1 µm.

[0014] Further control of the inner diameter of the secondary pores to 0.2 µm to 1 µm is advantageous to further increase the energy density and cycle stability of the battery.

[0015] In each embodiment, the porosity of the active material of a positive electrode is 0.1% to 12%, optionally 0.1% to 10%.

[0016] Controlling the porosity of the active material of a positive electrode within a suitable range ensures, on the one hand, sufficient space to expose more (010) crystal planes, thereby generating more reactive sites and increasing the battery's energy density; on the other hand, it maintains sufficient mechanical strength to reduce the risk of breakage of the active material of a positive electrode during the manufacturing process. Both the electrical performance and the mechanical strength of the battery are taken into account.

[0017] In each embodiment, the average particle size D of the primary particles is 100 nm to 800 nm, optionally 100 nm to 500 nm.

[0018] Controlling the average particle size D of the primary particles within a suitable range enables the battery to exhibit high energy density, excellent performance and cycle stability, thus comprehensively improving the electrochemical performance of the battery.

[0019] In each embodiment, the Dv50 of the secondary particles is 3 µm to 12 µm, optionally 3 µm to 11 µm.

[0020] Controlling the secondary particles of the Dv50 within a suitable range allows the battery to exhibit high energy density, excellent performance and cycle stability, thus comprehensively improving the electrochemical performance of the battery.

[0021] In each embodiment, the SPAN value of the secondary particles is 0.8 to 1.5, optionally 0.8 to 1.3.

[0022] Controlling the SPAN value of the secondary particles within a suitable range allows the battery to exhibit high energy density, excellent performance and cycle stability, thus comprehensively improving the electrochemical performance of the battery.

[0023] In each embodiment, the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode is 200 µm². 2 up to 300 µm 2 , optionally 250 µm 2 up to 280 µm 2 .

[0024] Controlling the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode in a suitable region provides sufficient reactive sites, increases the energy density of the battery and improves its electrochemical performance.

[0025] A second aspect of this application concerns a manufacturing process for an active material of a positive electrode, comprising: A precursor is prepared by mixing a first raw material containing a nickel source and a manganese source with a complexing agent and a precipitating agent, and then carrying out a coprecipitation reaction. Optionally, the first raw material also contains an M1 source; The precursor is mixed with a lithium source and calcined to produce an active material for a positive electrode; or The precursor is mixed with a lithium source and calcined, then mixed with an M2 source and calcined again to produce an active material for a positive electrode; The active material of a positive electrode has the following general formula: Li a Ni x M1 y Mn z M2 1-x-y-z O2, where M1 and M2 each independently comprise one or more elements from Co, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg, Nb, with 0.8≤a≤1.2, 0.55≤x<1, 0 <y≤0,25, 0≤z≤0,2; das Aktivmaterial einer positiven Elektrode liegt in Form von Sekundärpartikeln vor, die durch Aggregation von Primärpartikeln gebildet werden, wobei die Sekundärpartikel Sekundärporen umfassen, die durch die Zwischenräume zwischen den Primärpartikeln gebildet werden, und der Innendurchmesser der Sekundärporen 0,1 µm bis 2 µm beträgt.

[0026] Through the coprecipitation reaction and control of the manganese source quantity, the synthesized precursor is designed to have multiple ring-shaped pores, thus yielding a positive electrode active material that includes secondary pores distributed between the primary particles. The above-mentioned fabrication process for the positive electrode active material is simple and cost-effective. The secondary pores in the synthesized positive electrode active material have an inner diameter of 0.1 µm to 2 µm, which facilitates the insertion and removal of lithium ions; simultaneously, the secondary pores can buffer the volume changes of the positive electrode active material during charging and discharging, thereby stabilizing the structure and improving cycle stability.

[0027] In each embodiment, the following applies: 0.8 ≤ a ≤ 1.2, 0.8 ≤ x < 1.0, 0 <y≤0,1, 0≤z≤0,1, optional 0,8≤a≤1,2, 0,85≤x≤0,96, 0<y≤0,02, 0≤z≤0,05.

[0028] In each embodiment, the precursor is a secondary precursor particle formed by the aggregation of primary precursor particles; The average particle size D' of the primary precursor particles is 150 nm to 500 nm, optionally 200 nm to 300 nm; The mean particle size Dv50' of the secondary precursor particles is 3 µm to 12 µm, optionally 6 µm to 8 µm.

[0029] By controlling the average particle size D' of the primary precursor particles and the mean particle size Dv50' of the secondary precursor particles within a suitable range, the size of the primary and secondary particles of the manufactured active material of a positive electrode can in turn be controlled within a suitable range, so that the battery has a high energy density and excellent cycle stability.

[0030] In each embodiment, the specific surface area of ​​the precursor is 2 m². 2 / g up to 40 m 2 / g, optional 25 m 2 / g up to 35 m 2 / G.

[0031] By controlling the specific surface area of ​​the precursor in a suitable area and thus the porosity of the active material of a positive electrode, the battery can exhibit high energy density, excellent discharge performance and cycle stability.

[0032] In each embodiment, the molar concentration of manganese in the first raw material is 0.02 mol / L to 1.5 mol / L, optionally 0.05 mol / L to 1.2 mol / L.

[0033] By controlling the molar concentration of manganese in the first raw material within a suitable range, the inner diameter of the pores in the active material of a positive electrode can in turn be controlled within a suitable range, so that the battery has a high energy density, excellent discharge behavior and good cycle stability.

[0034] In each embodiment, the pH value of the co-precipitation reaction is 9 to 12, optionally 9 to 11.

[0035] In each embodiment, the reaction temperature of the co-precipitation reaction is 50 °C to 80 °C, optionally 55 °C to 75 °C.

[0036] In each embodiment, the reaction time of the co-precipitation reaction is 6 h to 10 h, optionally 6.5 h to 9.5 h.

[0037] In each embodiment, the stirring speed of the co-precipitation reaction is 200 rpm to 500 rpm, optionally 230 rpm to 300 rpm.

[0038] Controlling the pH value, reaction temperature, reaction time and stirring speed of the coprecipitation reaction within a suitable range allows for a more uniform and efficient coprecipitation reaction, which is advantageous for the formation of ring-shaped pores with a suitable inner diameter distributed within the primary particles of the active material of a positive electrode, so that the battery exhibits high energy density, excellent discharge performance and cycle stability.

[0039] A third aspect of this application relates to a positive electrode plate comprising a positive current collector and a positive electrode film layer arranged on at least one surface of the positive current collector, wherein the positive electrode film layer comprises the active material of a positive electrode according to the first aspect of this application or the active material of a positive electrode produced according to the manufacturing process according to the second aspect of this application.

[0040] In each embodiment, the thickness of the positive electrode film layer is 200 µm to 400 µm, optionally 200 µm to 300 µm.

[0041] By controlling the thickness of the positive electrode film layer within a suitable range, sufficient active material can be provided at the positive electrode to increase the battery's energy density; at the same time, the influence on the solid-state diffusion pathway of lithium ions is reduced. Both the energy density and the battery's performance are thus taken into account.

[0042] A fourth aspect of this application concerns a secondary battery, comprising the positive electrode plate according to the third aspect.

[0043] A fifth aspect of this application concerns an electrical device, comprising the secondary battery according to the fourth aspect. DESCRIPTION OF THE FIGURES Fig. Figure 1 is a scanning electron microscope image of the active material of a positive electrode shown in embodiment 3 of this application; Fig.Figure 2 is a schematic representation of a secondary battery according to an embodiment of this application; Fig. 3 is an exploded view of the in Fig. 2 secondary battery shown according to an embodiment of this application; Fig. Figure 4 is a schematic representation of a battery module according to an embodiment of this application; Fig. Figure 5 is a schematic representation of a battery pack according to an embodiment of this application; Fig. 6 is an exploded view of the in Fig. 5 battery packs shown according to an embodiment of this application; Fig. Figure 7 is a schematic representation of an electrical device that uses a secondary battery as a power source, according to an embodiment of this application;

[0044] Explanation of the markings in the figures: 1 battery pack; 2 Upper case; 3 Lower case; 4 battery modules; 5 Secondary battery; 51 cases; 52 Electrode assembly; 53 Cover plate. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0045] The embodiments of the active material of a positive electrode, the manufacturing process, the positive electrode plate, the secondary battery, and the electrical devices of this application are described in detail below with appropriate reference to the figures. Occasionally, however, unnecessary details may be omitted. For example, detailed explanations of generally known facts or repetitions of actually identical structures may be avoided. This is intended to avoid unnecessarily lengthening the following description and to facilitate understanding by those skilled in the art. Furthermore, the figures and the following description serve to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter of the claims.

[0046] The “range” disclosed in this application is defined by a lower bound and an upper bound. The specified range is determined by selecting a lower bound and an upper bound, the selected lower and upper bounds defining the limits of a particular range. The range thus defined can include or exclude limits and can be combined arbitrarily. That is, any lower bound can be combined with any upper bound to form a range. For example, if the ranges 60–120 and 80–110 are specified for a particular parameter, it is assumed that the ranges 60–110 and 80–120 are also understood. Furthermore, if the minimum range values ​​1 and 2 and the maximum range values ​​3, 4, and 5 are specified, then the following ranges are to be expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5.In this application, unless otherwise specified, the numerical ranges "ab" are shorthand representations of any combination of real numbers from a to b, where both a and b are real numbers. For example, the range "0-5" means that all real numbers between 0 and 5 listed in this document have been considered, with "0-5" serving merely as an abbreviated representation of these number combinations. Furthermore, when it is stated that a parameter is an integer ≥ 2, this means that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0047] Unless otherwise stated, all embodiments and optional embodiments of this application may be combined to form new technical solutions.

[0048] Unless otherwise stated, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0049] Unless otherwise stated, all steps of this application may be performed sequentially or in any order, with sequential order being preferred. For example, the procedure includes steps (a) and (b), which indicates that the procedure may include steps (a) and (b) performed sequentially, or steps (b) and (a) performed sequentially. The procedure may also include step (c), for example, which means that step (c) may be added to the procedure in any order. Thus, for example, the procedure may include steps (a), (b), and (c), steps (a), (c), and (b), or steps (c), (a), and (b), etc.

[0050] Unless otherwise stated, the terms "including" and "comprehensive" used in this application can be either open or closed. For example, the terms "comprehensive" and "including" can mean that other, unlisted components may also be included, or that only the listed components may be included.

[0051] Unless otherwise stated, the term "or" is inclusive in this application. For example, the expression "A or B" means "A, B, or both A and B." More specifically, each of the following conditions satisfies the "A or B" condition: A is true (or present) and B is false (or not present); A is false (or not present) and B is true (or present); or both A and B are true (or present).

[0052] Ternary materials have become one of the most popular active materials for positive electrodes in secondary lithium batteries due to their high theoretical specific capacity, high discharge plateau, and low cost. However, due to limitations in manufacturing processes and structures, common ternary materials exhibit low process stability when carbonates are used as precipitating agents in the production of ternary material precursors. This results in materials with either excessively large or excessively small particle sizes. Furthermore, the bulky structure of ternary materials hinders the solid-state diffusion pathway of metal ions, preventing them from simultaneously achieving high energy density and performance.Therefore, it is necessary to develop an active material for a positive electrode that takes into account both the cycle stability and the performance of the battery in order to meet the application requirements of the next generation of electrochemical systems. [Active material of a positive electrode]

[0053] Building on this, this application offers an active material for a positive electrode, which has the following general formula: Li a Ni x M1 y Mn z M2 1-x-y-z O2, where M1 and M2 each independently contain one or more of the following elements: Co, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb, 0.8≤a≤1.2, 0.55≤x<1, 0 <y≤0,45, 0<y≤0,25 und 0≤z≤0,2; The active material of a positive electrode is in the form of secondary particles formed by the aggregation of primary particles, the secondary particles comprising secondary pores formed by the spaces between the primary particles, and the inner diameter of the secondary pores being 0.1 µm to 2 µm.

[0054] In this document, the term "primary particles" refers to particles of the active material of a positive electrode prior to their agglomeration.

[0055] In this document, the term "secondary pores" refers to the cavity structure that exists between the primary particles of the active material of a positive electrode.

[0056] In this document, the term "internal diameter of secondary pores" refers to the longest straight-line distance between any two points on the circumference of a single cavity between primary particles of the active material of a positive electrode.

[0057] In this document, the inner diameter of the pores can be tested using all methods known to a person skilled in the art. For example, a conductive adhesive is applied to the sample stage, a powdered sample of the active material of a positive electrode is evenly distributed on the conductive adhesive, the non-adherent powder is blown away with a bellows, gold is sprayed on, and argon plasma is used to cut a cross-section of the particles of the powdered sample. Scanning electron microscopy (SEM) images of the powdered samples are obtained under conditions of an accelerating voltage of 10 kV and an emission current of 10 mA. The inner diameter of the secondary pores is measured from the SEM images. At least three samples are measured, with data from at least 50 primary particles being acquired for each sample.The arithmetic mean of the measured values ​​is used as the inner diameter of the secondary pores of the sample.

[0058] In some embodiments, a in the chemical formula Li a Ni x M1 y Mn z M2 1-x-y-z O2 any value or any two-value range consisting of 0.8, 0.9, 1.0, 1.1, 1.2.

[0059] In some embodiments, x is represented in the chemical formula Li a Ni x M1 y Mn z M2 1-x-y-z O2 any value or any range consisting of any two values ​​from 0.56, 0.6, 0.7, 0.8, 0.9, 0.95, 0.995, 1.

[0060] In some embodiments, y in the chemical formula Li a Ni x M1 y Mn z M2 1-x-y-z O2 any value or any two values ​​in a range consisting of 0.01, 0.1, 0.15, 0.2, 0.22, 0.25.

[0061] In some embodiments, z is represented by the chemical formula Li a Ni x M1 y Mn z M2 1-x-y-z O2 any value or any two-value range consisting of 0, 0.1, 0.12, 0.15, 0.17, 0.2.

[0062] In some embodiments, the chemical formula Li applies a Ni x M1 y Mn z M2 1-x-y-z O2: 0.8≤a≤1.2, 0.90≤x≤1.0, 0≤y≤0.1.

[0063] In some embodiments, the chemical formula Li applies a Ni x M1 y Mn z M2 1-x-y-z O2: 0.8≤a≤1.2, 0.8≤x<1.0, 0 <y≤0,1, 0≤z≤0,1.

[0064] In some embodiments, the chemical formula Li applies a Ni x M1 y Mn z M2 1-x-y-z O2: 0.8≤a≤1.2, 0.85≤x≤0.96, 0 <y≤0,02, 0≤z≤0,05.

[0065] In some embodiments, the chemical formula of the active material of a positive electrode is Li aNi x Co y Mn z M2 1-x-y-z O2, with 0.8≤a≤1.2, 0.85≤x≤0.96, 0 <y≤0,02, 0≤z≤0,05.

[0066] In some embodiments, the chemical formula of the active material of a positive electrode is Li a Ni x Al y Mn z M2 1-x-y-z O2, with 0.8≤a≤1.2, 0.85≤x≤0.96, 0 <y≤0,02, 0≤z≤0,05.

[0067] By using the aforementioned materials, it can be ensured that the active material of a positive electrode has a high gravimetric capacity, so that the battery has a high discharge capacity and energy density.

[0068] In some embodiments, the inner diameter of the secondary pores can be selected from 0.1 µm, 0.2 µm, 0.4 µm, 0.5 µm, 0.6 µm, 0.8 µm, 1 µm, 1.2 µm, 1.4 µm, 1.5 µm, 1.6 µm, 1.8 µm, 2 µm or a range formed from any two of these points.

[0069] It is understood that the secondary pores lie between the primary particles and are distributed on the inner surface near the surface of the secondary particles. The secondary pores are evenly distributed within the secondary particles and exhibit a spherical arrangement. In cross-section through the center of mass of the secondary particles, the secondary pores can form a ring that extends in a ring-like shape within the secondary particles.

[0070] On the one hand, the secondary particles contain secondary pores formed by the spaces between primary particles, allowing the active material of a positive electrode to form three-dimensional pore channels. This shortens the solid-state diffusion path of lithium ions and improves battery performance. On the other hand, the presence of secondary pores exposes more (010) crystal planes, creating more reactive sites and increasing the gravimetric capacity and energy density of the material. Furthermore, the presence of secondary pores can also buffer the volume changes of the active material of a positive electrode during charging and discharging, thus stabilizing the structure and improving cycle stability.At the same time, by controlling the inner diameter of the secondary pores to 0.1 µm to 2 µm, the energy density and cycle stability of the battery can be significantly increased, thus comprehensively improving battery performance.

[0071] In some embodiments, the ratio of the shortest distance between the secondary pore and the surface of the secondary particle to the Dv50 of the secondary particle is 1 / 5 to 3 / 5. In some embodiments, the ratio of the shortest distance between the secondary pore and the surface of the secondary particle to the Dv50 of the secondary particle is 3 / 10 to 1 / 2. In some embodiments, the ratio of the shortest distance between the secondary pore and the surface of the secondary particle to the Dv50 of the secondary particle can be selected from 1 / 5, 3 / 10, 2 / 5, 1 / 2, 3 / 5, or any range formed by any two of these points.

[0072] Controlling the ratio of the shortest distance between the secondary pores and the surface of the secondary particles to the Dv50 of the secondary particles within a suitable range makes it possible both to increase the performance of the battery and to reduce the influence of the pores on the structure of the active material of a positive electrode.

[0073] In some embodiments, at least some of the primary particles further comprise primary pores with an inner diameter of 0.05 µm to 0.6 µm. In some embodiments, the inner diameter of the primary pores is 0.08 µm to 0.2 µm. In some embodiments, the inner diameter of the primary pores can be selected from 0.05 µm, 0.06 µm, 0.08 µm, 0.1 µm, 0.15 µm, 0.2 µm, 0.25 µm, 0.3 µm, 0.35 µm, 0.4 µm, 0.45 µm, 0.5 µm, 0.45 µm, 0.6 µm, or any range formed by any two of these values.

[0074] In this document, the term "primary pore" refers to the cavity structure that exists inside the primary particles of the active material of a positive electrode.

[0075] In this document, the term “inner diameter of primary pores” refers to the longest straight-line distance between any two points on the circumference of a single cavity within a primary particle of the active material of a positive electrode.

[0076] The presence of primary pores helps to further shorten the solid-state diffusion path of lithium ions and improve battery performance. Controlling the inner diameter of the primary pores within a suitable range allows for a balanced consideration of the battery's performance and energy density.

[0077] In this document, the inner diameter of the pores can be tested using all methods known to a person skilled in the art. For example, a conductive adhesive is applied to the sample stage, a powdered sample of the active material of a positive electrode is evenly distributed on the conductive adhesive, the non-adherent powder is blown away with a bellows, gold is sprayed on, and argon plasma is used to cut a cross-section of the particles of the powdered sample. Scanning electron micrographs (SEM) of the powdered samples are obtained using a transmission electron microscope (TEM) at an accelerating voltage of 100 kV and an emission current of 100 mA. The inner diameter of the primary pores is determined from the scanning electron micrographs. At least three samples are measured, with at least 50 primary particles measured in each sample.The arithmetic mean of the measured values ​​is used as the inner diameter of the primary pores of the respective sample.

[0078] In some embodiments, the inner diameter of the secondary pores is 0.2 µm to 1 µm. In some embodiments, the inner diameter of the secondary pores can be selected from 0.2 µm, 0.3 µm, 0.4 µm, 0.5 µm, 0.6 µm, 0.7 µm, 0.8 µm, 0.9 µm, 1 µm, or a range formed from any two of these points.

[0079] Further control of the inner diameter of the secondary pores to 0.2 µm to 1 µm is advantageous to further increase the energy density and cycle stability of the battery.

[0080] In some embodiments, the porosity of the active material of a positive electrode is 0.1% to 12%. In some embodiments, the porosity of the active material of a positive electrode is 0.1% to 10%. In some embodiments, the porosity of the active material of a positive electrode can be selected from 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, or any range formed from any two of these values.

[0081] In this document, “porosity” refers to the ratio of the pore volume in the active material of a positive electrode to the total volume of the active material of a positive electrode.

[0082] In this document, the porosity of the active material of a positive electrode can be tested using all methods known to a person skilled in the art. For example, the gas displacement method is used for measurements according to GB / T 24586. Porosity = (V1 - V2) / V1 × 100%, where V1 is the apparent volume of the sample and V2 is the actual volume of the sample.

[0083] Controlling the porosity of the active material of a positive electrode within a suitable range ensures, on the one hand, sufficient space to expose more (010) crystal planes, thereby generating more reactive sites and increasing the battery's energy density; on the other hand, it maintains sufficient mechanical strength to reduce the risk of breakage of the active material of a positive electrode during the manufacturing process. Both the electrical performance and the mechanical strength of the battery are taken into account.

[0084] In some embodiments, the average particle size D of the primary particles is 100 nm to 800 nm. In some embodiments, the average particle size D of the primary particles is 100 nm to 500 nm. In some embodiments, the average particle size D of the primary particles can be selected from 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, or any range formed from any two of these points.

[0085] In this document, the average particle size D of the primary particles can be tested using any method known to a person skilled in the art. For example, after imaging with a scanning electron microscope (ZEISS Sigma-02-33, Germany, 500x magnification), 200 to 600 complete and unobstructed primary particles of the active material of a positive electrode are randomly selected from the electron microscope images, and the largest diameter of each pore in the primary particle is recorded in the microscope image. The average value is used as the average particle size D.

[0086] In some embodiments, the Dv50 of the secondary particles is 3 µm to 12 µm. In some embodiments, the Dv50 of the secondary particles is 3 µm to 11 µm. In some embodiments, the Dv50 of the secondary particles can be selected from 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm, 10 µm, 11 µm, 12 µm, or any range formed from any two of these points.

[0087] In this document, the Dv50 of the secondary particles can be tested using all methods known to those skilled in the art. For example, according to GB / T 19077-2016, laser diffraction method for determining the particle size distribution, 0.1 g to 0.13 g of the active material sample from a positive electrode is weighed into a 50 ml beaker, 5 g of anhydrous ethanol is added, a magnetic stir bar approximately 2.5 mm long is inserted, and the beaker is sealed with cling film. The samples are subjected to ultrasonic treatment for 5 minutes and then transferred to a magnetic stirrer, where they are stirred at 500 rpm for more than 20 minutes. Two samples are taken from each product batch for testing. The test is performed using a Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd., UK. Here, Dv50 is the particle size corresponding to a cumulative volume fraction of 50% of the secondary particles of the active material from a positive electrode.

[0088] In some embodiments, the SPAN value of the secondary particles is 0.8 to 1.5. In some embodiments, the SPAN value of the secondary particles is 0.8 to 1.3. In some embodiments, the SPAN value of the secondary particles can be selected from 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, or any range formed by any two of these points.

[0089] In this document, the term “SPAN” refers to the distribution span, which is calculated as (Dv90 - Dv10) / Dv50 and represents the particle distribution of the active material of a positive electrode.

[0090] In this document, the SPAN value of the secondary particles can be tested using all methods known to a person skilled in the art. For example, to determine the Dv50 of the secondary particles of the active material of a positive electrode: According to GB / T 19077-2016, laser diffraction method for determining the particle size distribution, 0.1 g to 0.13 g of the active material sample of a positive electrode to be tested are weighed into a 50 ml beaker, 5 g of anhydrous ethanol are added, a magnetic stir bar approximately 2.5 mm long is inserted, and the beaker is sealed with cling film. The samples are subjected to ultrasonic treatment for 5 minutes and then transferred to a magnetic stirrer, where they are stirred at 500 rpm for more than 20 minutes. Two samples are taken from each product batch for testing. The test is performed using a Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd., UK.Here, Dv90 is the particle size corresponding to a cumulative volume fraction of 90% for the secondary particles of the active material of a positive electrode, Dv50 is the particle size corresponding to a cumulative volume fraction of 50% for the secondary particles of the active material of a positive electrode, and Dv10 is the particle size corresponding to a cumulative volume fraction of 10% for the secondary particles of the active material of a positive electrode. SPAN = (Dv90 - Dv10) / Dv50.

[0091] The average particle size D of the primary particles, the Dv50 of the secondary particles, and the SPAN value of the secondary particles are important parameters of the active material of a positive electrode that influence its structural properties. Controlling the average particle size D of the primary particles, the Dv50 of the secondary particles, and the SPAN value of the secondary particles within a suitable range is advantageous for improving the bulk density of the active material of a positive electrode, resulting in a battery with high energy density, excellent performance and cycle stability, and a comprehensive improvement in the battery's electrochemical performance.

[0092] In some embodiments, the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode is 200 µm². 2 up to 300 µm 2 .

[0093] In some embodiments, the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode is 250 µm². 2 up to 280 µm 2 In some embodiments, the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode can be 200 µm 2 , 210 µm 2 , 220 µm 2 , 230 µm 2 , 240 µm 2 , 250 µm 2 , 260 µm 2 , 270 µm 2 , 280 µm 2 , 290 µm 2 , 300 µm 2 or selected from any two of these points.

[0094] In this document, the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode can be tested using all methods known to a person skilled in the art. For example, the area of ​​the (010) crystal plane is measured with an X-ray powder diffractometer (XRD, instrument model: Bruker D8 ADVANCE) using Cu Kα as the target material; the voltage and current are 40 kV / 40 mA, the scan angle range is between 5° and 80°, the step size is 0.00836°, and the time for each step is 0.3 s.

[0095] Controlling the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode in a suitable region provides sufficient reactive sites, increases the energy density of the battery and improves its electrochemical performance.

[0096] In some embodiments, the gravimetric capacity of the active material of a positive electrode is 238 mAh / g to 250 mAh / g.

[0097] An active material of a positive electrode with high gravimetric capacitance is advantageous for improving energy density.

[0098] This application also provides a method for producing an active material for a positive electrode, comprising: A precursor is prepared by mixing a first raw material containing a nickel source and a manganese source with a complexing agent and a precipitating agent, and then carrying out a coprecipitation reaction. Optionally, the first raw material also contains an M1 source; The precursor is mixed with a lithium source and calcined to produce an active material for a positive electrode; or The precursor is mixed with a lithium source and calcined, then mixed with an M2 source and calcined again to produce the aforementioned active material of a positive electrode; The active material of a positive electrode has the following general formula: Li a Ni x M1 y Mn z M2 1-x-y-z O2, where M1 and M2 each independently comprise one or more elements from Co, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg, Nb, with 0.8≤a≤1.2, 0.55≤x<1, 0 <y≤0,25, 0≤z≤0,2; das Aktivmaterial einer positiven Elektrode liegt in Form von Sekundärpartikeln vor, die durch Aggregation von Primärpartikeln gebildet werden, wobei die Sekundärpartikel Sekundärporen umfassen, die durch die Zwischenräume zwischen den Primärpartikeln gebildet werden, und der Innendurchmesser der Sekundärporen 0,1 µm bis 2 µm beträgt.

[0099] In this document, the term "coprecipitation reaction" refers to a precipitation reaction in which a metal solution, a precipitating agent and a complexing agent react with each other at a specific temperature.

[0100] In some embodiments, the M1 source comprises one or more of the following sources: cobalt source, aluminum source, boron source, antimony source, titanium source and magnesium source.

[0101] In some embodiments, the M2 source comprises one or more of the following sources: cobalt source, aluminum source, boron source, antimony source, titanium source and magnesium source.

[0102] In some embodiments, the nickel source comprises one or more of the following substances: nickel sulfate, nickel chloride, nickel nitrate, and nickel acetate.

[0103] In some embodiments, the manganese source comprises one or more of the following substances: manganese sulfate, manganese chloride, manganese nitrate, and manganese acetate.

[0104] In some embodiments, the lithium source comprises one or more of the following substances: lithium hydroxide, lithium carbonate, lithium oxide, lithium phosphate, lithium dihydrogen phosphate, and lithium acetate.

[0105] In some embodiments, the cobalt source comprises one or more of the following substances: cobalt sulfate, cobalt chloride, cobalt nitrate, and cobalt acetate.

[0106] In some embodiments, the antimony source comprises one or more of the following substances: antimony sulfate, antimony chloride, antimony nitrate, and antimony acetate.

[0107] Through the coprecipitation reaction and control of the manganese source quantity, the synthesized precursor is designed to have multiple ring-shaped pores, thus yielding a positive electrode active material that includes secondary pores distributed between the primary particles. The above-mentioned fabrication process for the positive electrode active material is simple and cost-effective. The secondary pores in the synthesized positive electrode active material have an inner diameter of 0.1 µm to 2 µm, which facilitates the insertion and removal of lithium ions; simultaneously, the pores can buffer the volume changes of the positive electrode active material during charging and discharging, thereby stabilizing the structure and improving cycle stability.

[0108] In some embodiments: 0.8 ≤ a ≤ 1.2, 0.8 ≤ x < 1.0, 0 <y≤0,1, 0≤z≤0,1.

[0109] In some embodiments: 0.8 ≤ a ≤ 1.2, 0.85 ≤ x ≤ 0.96, 0 <y≤0,02, 0≤z≤0,05.

[0110] In some embodiments, the precursor is the secondary precursor particle, which is formed by the aggregation of primary precursor particles.

[0111] In some embodiments, the average particle size D' of the primary precursor particles is 150 nm to 500 nm. In some embodiments, the average particle size D' of the primary precursor particles is 200 nm to 300 nm.

[0112] In some embodiments, the mean particle size Dv50' of the secondary precursor particles is 3 µm to 12 µm. In some embodiments, the mean particle size Dv50' of the secondary precursor particles is 6 µm to 8 µm.

[0113] In some embodiments, the average particle size D' of the primary precursor particles can be selected from 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, or any range formed by any two of these values. In some embodiments, the mean particle size Dv50' of the secondary precursor particles can be selected from 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm, 10 µm, 11 µm, 12 µm, or any range formed by any two of these values.

[0114] In this document, the average particle size D' of the primary precursor particles can be tested using any method known to a person skilled in the art. For example, after imaging with a scanning electron microscope (ZEISS Sigma-02-33, Germany, 500x magnification), 200 to 600 complete and unobstructed primary precursor particles are randomly selected from the electron microscope images, and the largest diameter of each pore in the primary precursor particle is recorded in the microscope image. The average value is used as the average particle size D'.

[0115] In this document, the mean particle size Dv50' of the secondary precursor particles can be tested using any method known to those skilled in the art. For example, according to GB / T 19077-2016, laser diffraction method for determining the particle size distribution, 0.1 g to 0.13 g of the secondary precursor particle sample to be tested are weighed into a 50 ml beaker, 5 g of anhydrous ethanol are added, a magnetic stir bar approximately 2.5 mm long is inserted, and the beaker is sealed with cling film. The samples are subjected to ultrasonic treatment for 5 minutes and then transferred to a magnetic stirrer, where they are stirred at 500 rpm for more than 20 minutes. Two samples are taken from each product batch for testing. The test is performed using a Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd., UK. Here, Dv50' is the particle size corresponding to a cumulative volume fraction of 50% of the secondary precursor particles.

[0116] By controlling the average particle size D' of the primary precursor particles and the mean particle size Dv50' of the secondary precursor particles within a suitable range, the size of the primary and secondary particles of the manufactured active material of a positive electrode can in turn be controlled within a suitable range, so that the battery has a high energy density and excellent cycle stability.

[0117] In some embodiments, the specific surface area of ​​the precursor is 2 m². 2 / g up to 40 m 2 / g. In some embodiments, the specific surface area of ​​the precursor is 25 m². 2 / g up to 35 m 2 / g. In some embodiments, the specific surface area of ​​the precursor can be 2 m². 2 / g, 5 m 2 / g, 10 m 2 / g, 12 m 2 / g, 15 m 2 / g, 16 m 2 / g, 17 m 2 / g, 18 m 2 / g, 19 m2 / g, 20 m 2 / g, 21 m 2 / g, 22 m 2 / g, 23 m 2 / g, 24 m 2 / g, 25 m 2 / g, 26 m 2 / g, 28 m 2 / g, 30 m 2 / g, 32 m 2 / g, 34 m 2 / g, 35 m 2 / g, 36 m 2 / g, 38 m 2 / g, 40 m 2 / g or an area formed from any two of these points can be selected.

[0118] In this document, the specific surface area of ​​the precursor can be tested using all methods known to those skilled in the art. As an example, reference is made to GB / T 19587-2017 "Determination of the specific surface area of ​​solids by gas adsorption BET method". The determination is carried out using the TriStar II 3020 instrument. The precursor is dispersed in a dispersion medium (ethanol), treated ultrasonically for 30 minutes, then dried in a vacuum drying oven, and finally the specific surface area of ​​the precursor is measured with a surface analyzer.

[0119] By controlling the specific surface area of ​​the precursor in a suitable area and thus the porosity of the active material of a positive electrode, the battery can exhibit high energy density, excellent discharge performance and cycle stability.

[0120] In some embodiments, the molar concentration of manganese in the first raw material is 0.02 mol / L to 1.5 mol / L. In some embodiments, the molar concentration of manganese in the first raw material is 0.05 mol / L to 1.2 mol / L. In some embodiments, the molar concentration of manganese in the first raw material can be selected from 0.02 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.4 mol / L, 1.5 mol / L, or any range formed by any two of these values.

[0121] By controlling the molar concentration of manganese in the first raw material within a suitable range, the inner diameter of the pores in the active material of a positive electrode can in turn be controlled within a suitable range, so that the battery has a high energy density, excellent discharge behavior and good cycle stability.

[0122] In some embodiments, the precipitating agent comprises one or more of the following substances: sodium hydroxide, sodium carbonate, sodium bicarbonate and ammonium bicarbonate.

[0123] In some embodiments, the complexing agent comprises one or more of the following substances: ammonia, lactic acid and polyvinylpyrrolidone.

[0124] In some embodiments, the pH of the coprecipitation reaction is 9 to 12. In some embodiments, the pH of the coprecipitation reaction is 9 to 11. In some embodiments, the pH of the coprecipitation reaction can be selected from 9, 10, 11, 12, or any range formed by any two of these points.

[0125] In some embodiments, the reaction temperature of the co-precipitation reaction is 50 °C to 80 °C. In some embodiments, the reaction temperature of the co-precipitation reaction is 55 °C to 75 °C. In some embodiments, the reaction temperature of the co-precipitation reaction can be selected from 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, or any range formed by any two of these points.

[0126] In some embodiments, the reaction time of the co-precipitation reaction is 6 h to 10 h. In some embodiments, the reaction time of the co-precipitation reaction is 6.5 h to 9.5 h. In some embodiments, the reaction time of the co-precipitation reaction can be selected from 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h, 9.5 h, 10 h, or any range formed by any two of these points.

[0127] In some embodiments, the stirring speed of the co-precipitation reaction is 200 rpm to 500 rpm. In some embodiments, the stirring speed of the co-precipitation reaction is 230 rpm to 300 rpm. In some embodiments, the stirring speed of the co-precipitation reaction can be selected from 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, or any range formed by any two of these points.

[0128] Controlling the pH value, reaction temperature, reaction time and stirring speed of the coprecipitation reaction within a suitable range allows for a more uniform and efficient coprecipitation reaction, which is advantageous for the formation of ring-shaped pores with a suitable inner diameter distributed within the primary particles of the active material of a positive electrode, so that the battery exhibits high energy density, excellent discharge performance and cycle stability. [Positive electrode]

[0129] The positive electrode plate comprises a positive current collector and a positive electrode film layer arranged on at least one surface of the positive current collector, wherein the positive electrode film layer comprises an active material of a positive electrode according to any embodiment or the active material of a positive electrode produced according to the manufacturing process according to any embodiment.

[0130] For example, the positive current collector has two surfaces opposite each other in its thickness direction, and the positive electrode layer is arranged on one or both of the two opposite surfaces of the positive current collector.

[0131] In some embodiments, the basis weight of the positive electrode film layer is 24 mg / cm². 2 up to 46 mg / cm² 2 In some embodiments, the basis weight of the positive electrode film layer can be 24 mg / cm².2 , 25 mg / cm 2 , 26 mg / cm 2 , 28 mg / cm 2 , 30 mg / cm 2 , 32 mg / cm 2 , 34 mg / cm 2 , 35 mg / cm 2 , 36 mg / cm 2 , 38 mg / cm 2 , 40 mg / cm 2 , 42 mg / cm 2 , 44 mg / cm 2 , 45 mg / cm 2 , 46 mg / cm 2 or selected from any two of these points.

[0132] The areal weight of the positive electrode film layer is determined by measuring the coating weight (g) of the one-sided positive electrode film layer and the coating area (cm²). 2 The surface weight of the positive electrode film layer on one side (number of measuring points > 14) is determined. Specifically: Surface weight of the positive electrode film layer = coating weight of the positive electrode film layer on one side (g) / coating area of ​​the positive electrode film layer (cm²). 2 ).

[0133] In some embodiments, the thickness of the positive electrode film layer is 200 µm to 400 µm. In some embodiments, the thickness of the positive electrode film layer is 200 µm to 300 µm. In some embodiments, the thickness of the positive electrode film layer can be selected from 200 µm, 220 µm, 240 µm, 250 µm, 260 µm, 280 µm, 300 µm, 320 µm, 340 µm, 350 µm, 360 µm, 380 µm, 400 µm, or any range formed by any two of these values.

[0134] By controlling the thickness of the positive electrode film layer within a suitable range, sufficient active material can be provided at the positive electrode to increase the battery's energy density; at the same time, the influence on the solid-state diffusion pathway of lithium ions is reduced. Both the energy density and the battery's performance are thus taken into account.

[0135] In some embodiments, the positive electrode current collector can be a metal foil or a composite current collector. For example, aluminum foil can be used as the metal foil. The composite current collector can comprise a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite current collector can be manufactured by depositing metallic materials (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) onto polymer substrates (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0136] In some embodiments, the positive electrode film layer may optionally contain a binder. For example, the binder may contain at least one of the following substances: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene propylene terpolymer, PVDF-hexafluoropropylene tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin.

[0137] In some embodiments, the positive electrode film layer may optionally contain a conductive material. For example, the conductive material may contain at least one of the following materials: superconducting carbon, carbon black, carbon black, Ketjen black, carbon nanoparticles, carbon nanotubes, graphene, and carbon nanofibers.

[0138] In some embodiments, the positive electrode plate can be produced by dispersing the aforementioned components for the production of the positive electrode plate, such as positive active material, conductive agent, binder, and other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode suspension; applying the positive electrode suspension to the current collector of the positive electrode; and subsequently obtaining the positive electrode plate after drying, cold pressing, and other processes. [Negative electrode]

[0139] The negative electrode plate comprises a negative current collector and a negative electrode film layer arranged on at least one surface of the negative current collector, wherein the negative electrode film layer comprises a negative active material.

[0140] For example, the negative current collector has two surfaces opposite each other in its thickness direction, and the negative electrode layer is arranged on one or both of the two opposite surfaces of the negative current collector.

[0141] In some embodiments, the negative electrode current collector can be a metal foil or a composite current collector. For example, copper foil can be used as the metal foil. The composite current collector can comprise a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite current collector can be manufactured by depositing metallic materials (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) onto polymer substrates (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0142] In some embodiments, the active material of the negative electrode may be a negative electrode active material known to those skilled in the art and used in batteries. For example, the negative electrode active material may comprise at least one of the following: synthetic graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. The silicon-based materials may be selected from at least one of the following: elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based materials may be selected from at least one of the following: elemental tin, tin oxides, and tin alloys.However, the present application is not limited to these materials; other traditional materials that can be used as active materials for the negative electrode of a battery may also be used. These active materials for negative electrodes may be used alone or in combination with one or more.

[0143] In some embodiments, the active material of a positive electrode contains silicon oxide.

[0144] In some embodiments, the mass fraction of silicon oxide, based on the total mass of the active material of the negative electrode, is 20% to 100%. In some embodiments, the mass fraction of silicon oxide, based on the total mass of the active material of the negative electrode, is 50% to 100%.

[0145] In some embodiments, the negative electrode film layer may optionally contain a binder. At least one of the following substances may be selected as the binder: 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).

[0146] In some embodiments, the negative electrode film layer may optionally contain a conductive material. At least one of the following materials may be selected as the conductive material: superconducting carbon, carbon black, carbon black, Ketjen black, carbon nanoparticles, carbon nanotubes, graphene, and carbon nanofibers.

[0147] In some embodiments, the negative electrode film layer optionally contains further additives, such as thickening agents (e.g. sodium carboxymethylcellulose (CMC-Na)), etc.

[0148] In some embodiments, the negative electrode plate can be produced as follows: the aforementioned components for producing the negative electrode plate, such as the active material of the negative electrode, the conductive agent, the binder, and any other components, are dispersed in a solvent (e.g., deionized water) to form a negative electrode suspension; the negative electrode suspension is applied to the negative current collector, and after process steps such as drying and cold pressing, the negative electrode plate is obtained. [Separator film]

[0149] In some embodiments, the secondary battery also contains a separator film. Any known separator film with a porous structure and good chemical and mechanical stability can be selected.

[0150] In some embodiments, the separator film material can be selected from at least one of the following: glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single-layer film or a multi-layer composite film. If the separator film is a multi-layer composite film, the materials of the individual layers can be the same or different.

[0151] In some embodiments, the positive electrode plate, the negative electrode plate and the separator film can be processed into an electrode assembly by a winding process or a stacking process.

[0152] In some embodiments, the secondary battery comprises the negative electrode plate, the separator foil, the electrolyte, and the positive electrode plate according to some embodiments.

[0153] In some embodiments, the secondary battery includes a lithium secondary battery.

[0154] In some embodiments, the energy density of the secondary battery is 380 Wh / kg to 500 Wh / kg.

[0155] In some embodiments, the secondary battery may include a casing. This casing can be used to encapsulate the aforementioned electrode assembly and the electrolyte.

[0156] In some embodiments, the secondary battery casing can be a rigid housing, e.g., a housing made of hard plastic, aluminum, steel, etc. The secondary battery casing can also be a flexible housing, e.g., a bag-shaped soft packaging. Materials for flexible housings can include plastics such as polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0157] The shape of the secondary battery according to the present application can be cylindrical, rectangular, or any other shape. For example, shows Fig. 2 a secondary battery 5 with a rectangular structure as an example.

[0158] In some embodiments, with reference to Fig.3, the casing comprises a housing 51 and a cover plate 53. The housing 51 can comprise a base plate and a side plate connected to the base plate, the base plate and side plate forming a receiving space. The housing 51 has an opening connected to the receiving space, and the cover plate 53 can cover the opening to close the receiving space. The positive electrode plate, the negative electrode plate, and the separator film can be manufactured into an electrode assembly 52 by a winding or a stacking process. The electrode assembly 52 is encapsulated in the receiving space. The electrolyte permeates the electrode assembly 52. ​​The number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, which the person skilled in the art can select according to the specific requirements.

[0159] In some embodiments, secondary batteries can be assembled into a battery module. The number of secondary batteries contained in the battery module can be one or more, which a person skilled in the art can select depending on the application and capacity of the battery module.

[0160] Fig. Figure 4 shows a battery module 4 as an example. As shown from Fig. As shown in Figure 4, several secondary batteries 5 can be arranged longitudinally within battery module 4. Of course, it can also be arranged in any other way. Furthermore, the multiple secondary batteries 5 can be secured with fastening elements.

[0161] Alternatively, the battery module 4 can also include a housing with a receiving space in which a large number of secondary batteries 5 can be received.

[0162] In some embodiments, the aforementioned battery modules can further be assembled into a battery pack. The number of battery modules contained in the battery pack can be one or more, which can be selected by a person skilled in the art depending on the application and capacity of the battery pack.

[0163] Fig. 5 and Fig. Figure 6 shows an example of a battery pack 1. In the Fig. 5 and Fig. Figure 6 shows that the battery pack 1 can comprise a battery housing and a plurality of battery modules 4 arranged within the battery housing. The battery housing consists of an upper housing part 2 and a lower housing part 3. The upper housing part 2 can cover the lower housing part 3, thus forming an enclosed space for the battery modules 4. The multiple battery modules 4 can be arranged arbitrarily within the battery housing.

[0164] Furthermore, the present application also provides an electrical device comprising at least one of the secondary batteries, battery modules, or battery packs provided for in this application. The secondary battery, battery module, or battery pack can be used as a power source or as an energy storage unit for the electrical device. Electrical devices include, among others, mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid vehicles, plug-in hybrid vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships, satellites, and energy storage systems, etc.

[0165] Depending on the requirements of its use, the secondary battery, battery module or battery pack can be selected for the electrical device.

[0166] Fig.Figure 7 shows an electrical device as an example. The electrical consumer is a pure electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, etc. To meet the electrical consumer's requirements for high power and high energy density of the secondary battery, battery packs or battery modules can be used.

[0167] Another example of such a device would be a mobile phone, a tablet, a laptop, etc. This type of device typically requires a lightweight and thin design and can use a secondary battery as a power source. Examples of implementation

[0168] The embodiments described below are examples of the present application. These embodiments are examples and serve only to illustrate this application; they are not to be construed as limiting this application. Unless a specific technology or conditions are indicated in the embodiments, the technologies or conditions described in the technical literature or the product manual apply. Unless the manufacturers of the reagents or instruments used are specified, they are exclusively commercially available products. I. Manufacturing process Example 11) Production of the active material of a positive electrode

[0169] A nickel-cobalt-manganese solution with a molar ratio of nickel:cobalt:manganese = 96:1:3 is prepared and adjusted to a concentration of 2 mol / L. Nickel sulfate, cobalt sulfate, and manganese sulfate, respectively, serve as starting materials for soluble nickel, cobalt, and manganese. The molar concentration of manganese ions is 0.3 mol / L. Additionally, a 3 mol / L sodium hydroxide solution and a 6 mol / L ammonia solution are provided.

[0170] Under a nitrogen atmosphere, the aforementioned nickel-cobalt-manganese solution, the sodium hydroxide solution, and the ammonia solution are simultaneously added to a reactor for precipitation. The rotational speed is set to 300 rpm, the temperature to 80 °C, and the reaction time to 10 h. The pH of the system is adjusted to 9.1, and the concentration of the ammonia solution to 6 mol / L. After completion of the precipitation reaction, the reaction mixture is transferred to a slurry tank for aging and washing. Following dehydration, the mixture is dried for 10 h at 120 °C in a drying oven. A precursor is obtained by sieving and demagnetization.

[0171] The precursor and lithium hydroxide are mixed uniformly in a specific ratio, with a molar Li / Me ratio of 1.03; Me denotes the total molar content of nickel, cobalt and manganese.

[0172] The uniformly mixed material is placed in an oven and calcined at 760 °C for 20 hours at a heating rate of 3 °C / min. The atmosphere has an oxygen content of ≥ 98%. The material is then cooled in the oven, yielding a base material.

[0173] Under a nitrogen atmosphere, the base material, cobalt boride, and titanium boride are mixed in a high-speed mixer in a mass ratio of 1:0.015:0.0041. The mixture is then calcined in an oven at a calcination temperature of 350 °C for 5 hours under a nitrogen atmosphere to obtain the product. The product is washed with water for 30 minutes, centrifuged, filtered, and then dried by vibration. This process yields the active material of a positive LiNi electrode. 0,96 Co 0,01 Mn 0,028 Ti 0,001 B 0,001 O2 is obtained, which includes the secondary pores distributed between the primary particles. 2) Production of the positive electrode plate

[0174] The aforementioned active material of a positive electrode, the conductive carbon black and the binder polyvinylidene fluoride (PVDF), are added to N-methylpyrrolidone in a mass ratio of 97:1:2 and mixed and stirred for 0.5 to 6 hours to obtain a suspension for the positive electrode. The suspension is then applied evenly to the positive current collector made of aluminum foil. After drying, cold pressing, and cutting, the positive electrode plate is obtained. 3) Production of the negative electrode plate

[0175] Synthetic graphite doped with silicon dioxide (SiO₂), conductive carbon black, carbon nanotubes (CNTs), the binder styrene-butadiene rubber (SBR), and the thickener sodium carboxymethylcellulose (CMC) are dispersed in deionized water in a weight ratio of 94.5:1:0.375:2.8:1.325, with the mass fraction of SiO₂ being XX, based on the mass of synthetic graphite. The mixture is stirred for 0.5 to 6 hours to obtain a suspension for the negative active material layer. This suspension is applied evenly in layers to the negative current collector made of copper foil. After drying, cold pressing, and cutting, the positive electrode plate is obtained. 4) Electrolyte

[0176] In a glovebox with an argon atmosphere (H₂O < 0.1 ppm, O₂ < 0.1 ppm), the lithium salt LiPF₆ / LIFSI is dissolved in an organic solvent mixture of ethylene carbonate, ethyl methyl carbonate, diethyl carbonate, and fluoroethylene carbonate (volume ratio 1:1:1:1) and stirred until homogeneity is achieved. An electrolyte with a lithium salt concentration of 1 mol / L is obtained. 5) Separator film

[0177] A polypropylene film is used as the base membrane. A 1 µm thick aluminum oxide layer (CCS) and a 1 µm thick polyvinylidene fluoride layer (PCS) are applied to this membrane. 6) Battery production

[0178] The positive electrode plate, separator foil, and negative electrode plate are stacked on top of each other in that order, with the separator foil positioned between the positive and negative plates for insulation. The stack is then wound into a bare cell. Tabs are welded to this bare cell, and the cell is inserted into an aluminum casing. It is then dried at 80°C to remove water. Finally, the electrolyte is added, and the casing is sealed, resulting in an uncharged battery.

[0179] The uncharged battery then undergoes a series of processes, including settling, hot and cold pressing, shaping, design and capacity testing, to obtain the lithium battery product according to embodiment 1. Example 2

[0180] The battery in embodiment 2 is manufactured similarly to the battery in embodiment 1; however, the manufacturing process of the precursor of the active material of a positive electrode is adapted to adjust the secondary pore size of the active material of a positive electrode. The specific parameters are listed in Tables 1 and 2. Example 3

[0181] The battery in embodiment 3 is manufactured similarly to the battery in embodiment 1. However, the manufacturing process of the precursor of the active material of a positive electrode is adapted such that the primary particles of the active material of a positive electrode have primary pores. The exact parameters are listed in Tables 1 and 2. Exemplary embodiments 4 to 11

[0182] The batteries in embodiments 4 to 11 are manufactured similarly to the battery in embodiment 1. However, the manufacturing process of the precursor of the active material of a positive electrode is adapted to adjust the inner diameter, porosity, and SPAN value of the secondary pores of the active material of a positive electrode. The exact parameters are listed in Tables 1 and 2. Exemplary embodiments 12 to 21

[0183] The batteries in embodiments 12 to 21 are manufactured using a similar process to that in embodiment 3. However, the manufacturing process of the precursor, as well as the heating rate, temperature, or time during the calcination of the precursor and the lithium salt, are adjusted to modify the particle size of the primary particles D, the particle size of the secondary particles Dv50, or the SPAN value of the active material of a positive electrode. Specifically: Example 12: The pH of the coprecipitation reaction in the precursor manufacturing process is 9.4. The precursor and lithium hydroxide are mixed in a specific ratio and then calcined. The heating rate is 3 °C / min, and the temperature is maintained at 800 °C for 22 hours. Example 13: The pH of the coprecipitation reaction in the precursor manufacturing process is 9.3. The precursor and lithium hydroxide are mixed in a specific ratio and then calcined. The heating rate is 3 °C / min, and the temperature is maintained at 790 °C for 22 hours. Example 14: The pH of the coprecipitation reaction in the precursor manufacturing process is 9.1. The precursor and lithium hydroxide are mixed in a specific ratio and then calcined. The heating rate is 3 °C / min, and the temperature is maintained at 780 °C for 21 hours. Exemplary embodiment 15: The stirring speed of the co-precipitation reaction in the precursor manufacturing process is 290 rpm. The precursor and Lithium hydroxide is mixed in a specific ratio and then calcined. The heating rate is set to 3 °C / min, and the temperature is maintained at 740 °C for 18 hours. Example 16: The precursor and lithium hydroxide are mixed in a specific ratio and then calcined. The heating rate is 7 °C / min, and the mixture is held at 760 °C for 20 h. Example 17: The precursor and lithium hydroxide are mixed in a specific ratio and then calcined. The heating rate is 2.5 °C / min, and the mixture is held at 760 °C for 20 hours. Example 18: The precursor and lithium hydroxide are mixed in a specific ratio and then calcined. The heating rate is 5 °C / min, and the mixture is held at 760 °C for 20 h. Example 19: The precursor and lithium hydroxide are mixed in a specific ratio and then calcined. The heating rate is 2 °C / min, and the mixture is held at 760 °C for 20 h. Exemplary embodiments 20 to 21

[0184] The batteries in embodiments 20 and 21 are manufactured similarly to those in embodiment 3; however, the manufacturing process of the precursor of the active material of a positive electrode is adapted to adjust the SPAN value of the active material of a positive electrode. The specific parameters are listed in Tables 1 and 2. Exemplary embodiments 22 to 23

[0185] The batteries in embodiments 22 and 23 are manufactured similarly to the battery in embodiment 3, except that the thickness of the positive electrode foil is adjusted. The exact parameters are listed in Tables 1 and 2. Exemplary embodiments 24 to 27

[0186] The batteries in embodiments 24 to 27 are manufactured similarly to those in embodiment 3. However, the manufacturing process of the precursor of the active material for the positive electrode is adapted to adjust the inner diameter of the primary pores or the average particle size D of the primary particles of the active material of a positive electrode. The exact parameters are listed in Tables 1 and 2.

[0187] Exemplary embodiment 28: The battery in exemplary embodiment 28 is manufactured according to a similar process to the battery in exemplary embodiment 3, however, the molar ratio of nickel to manganese in the manufacturing process of the precursor for the active material of a positive electrode is adjusted to 97:3, resulting in the active material of a positive electrode LiNi 0,97 Mn 0,028 Ti 0,001 B 0,001 O2 leads.

[0188] Exemplary embodiment 29: The battery in exemplary embodiment 29 is manufactured according to a similar process to the battery in exemplary embodiment 3, however, the molar ratio of nickel, aluminum and manganese in the manufacturing process of the precursor for the active material of a positive electrode is adjusted to 96:1:3, resulting in the active material of a positive electrode LiNi 0,96 Al 0,01 Mn 0,028 Ti 0,001 B 0,001 O2 leads.

[0189] Exemplary embodiment 30: The battery in exemplary embodiment 30 is manufactured according to a similar process to the battery in exemplary embodiment 3, but without the final doping reaction with cobalt boride and titanium boride, whereby the active material of a positive electrode is LiNi 0,96 Co 0,01 Mn 0,03 O2 is produced. Comparative example 1

[0190] The battery in Comparative Example 1 is manufactured using a similar process to the battery in Exemplary Example 1; however, the primary particles of the manufactured active material of a positive electrode have a solid structure. The exact manufacturing process is as follows: A nickel-cobalt-manganese solution with a molar ratio of nickel:cobalt:manganese = 96:1:3 is prepared and adjusted to a concentration of 2 mol / L. Nickel sulfate, cobalt sulfate, and manganese sulfate, respectively, serve as starting materials for soluble nickel, cobalt, and manganese. The molar concentration of manganese ions is 0.005 mol / L. Additionally, a 0.8 mol / L sodium hydroxide solution and a 6 mol / L ammonia solution are provided.

[0191] Under a nitrogen atmosphere, the aforementioned nickel-cobalt-manganese solution, the sodium hydroxide solution, and the ammonia solution are simultaneously added to a reactor for precipitation. The rotational speed is set to 600 rpm, the temperature to 78 °C, and the reaction time to 9 h. The pH of the system is adjusted to 11.5, and the concentration of the ammonia solution to 6 mol / L. After completion of the precipitation reaction, the reaction mixture is transferred to a slurry tank for aging and washing. Following dehydration, the mixture is dried for 10 h at 120 °C in a drying oven. Sieving and demagnetization yield a densely packed precursor.

[0192] The precursor and lithium hydroxide are mixed uniformly in a specific ratio, with a molar Li / Me ratio of 1.03; Me denotes the total molar content of nickel, cobalt and manganese.

[0193] The homogenized material is placed in an oven with an oxygen atmosphere and calcined at 800 °C for 24 hours at a heating rate of 5 °C / min. The atmosphere has an oxygen content of ≥ 98%. The material is then cooled in the oven, yielding a base material.

[0194] Under a nitrogen atmosphere, the base material, cobalt boride, and titanium boride are mixed in a high-speed mixer in a mass ratio of 1:0.015:0.0041. The mixture is then calcined in an oven at a calcination temperature of 350 °C for 5 hours under a nitrogen atmosphere to obtain the product. The product is washed with water for 30 minutes, centrifuged, filtered, and then dried by vibration to form the active material of a positive LiNi electrode. 0,96 Co 0,01 Mn 0,028 Ti 0,001 B 0,001 To obtain O2 without pores. Comparative example 2 to 3

[0195] The batteries in comparison examples 2 and 3 are manufactured using a similar process to that of comparison example 1. However, the parameters of the manufacturing process for the active material of a positive electrode are adjusted so that the inner pore diameter of the primary particles of the active material of a positive electrode is 0.05 µm and 3 µm, respectively. The exact parameters are listed in Tables 1 and 2. Comparative example 4

[0196] The battery in comparative example 4 is manufactured using a similar method to that in embodiment 28, however, the manufacturing process is adapted so that the active material of a positive electrode has no pores, as detailed in Table 4. Comparative example 5 to 6

[0197] The batteries in comparative examples 5 and 6 are manufactured using a similar process to that in comparative example 4. However, the parameters of the manufacturing process for the active material of a positive electrode are adjusted so that the inner pore diameters of the primary particles of the active material of a positive electrode are 0.05 micrometers and 3 micrometers, respectively, as detailed in Table 14. Comparative example 7

[0198] The battery of Comparative Example 7 is manufactured in a similar manner to the battery of Exemplary Example 29, however, the manufacturing process is adapted so that the active material of a positive electrode has no pores, as detailed in Table 5. Comparative example 8

[0199] The battery of Comparative Example 8 is manufactured in a similar manner to the battery of Exemplary Example 30, however, the manufacturing process is adapted so that the active material of a positive electrode has no pores, as detailed in Table 6. II. Performance Tests 1. Performance test of the active material of a positive electrode 1) Testing the pore inner diameter

[0200] Conductive adhesive is applied to the sample stage. A powdered sample is taken from each sample of the active material of a positive electrode from the implementation and comparison examples and evenly distributed on the conductive adhesive. Non-adherent powder is blown away with a bellows. A gold layer is then sputtered on, and a cross-section of the powdered sample is prepared using argon plasma. Scanning electron microscopy (SEM) images of the powdered sample are acquired using an instrument such as the ZEISS Sigma 300 at an accelerating voltage of 10 kV and an emission current of 10 mA. The inner diameter of the primary pores is measured from the SEM images. At least three samples are measured, with at least 50 primary particles measured from each sample. The arithmetic mean is used as the inner diameter of the primary pores in the respective sample. 2) Porosity testing

[0201] According to GB / T 24586, the gas displacement method is used for measurement. Porosity = (V1 - V2) / V1 × 100%, where V1 is the apparent volume of the sample and V2 is the actual volume of the sample. 3) Examination of the specific surface area of ​​the precursor

[0202] See GB / T 19587-2017 “Determination of the specific surface area of ​​solids by gas adsorption using the BET method”. The determination is carried out using the TriStar II 3020 instrument. The precursor is dispersed in a dispersion medium (ethanol), ultrasonically treated for 30 minutes, then dried in a vacuum drying oven, and finally the specific surface area of ​​the precursor is measured with a surface analyzer. 4) Testing of primary particle size

[0203] Testing the primary particle size D of the active material of a positive electrode: After imaging with a scanning electron microscope (ZEISS Sigma-02-33, Germany, 500x magnification), 200 to 600 primary particles of the active material of a positive electrode with complete shape and no occlusion are randomly selected from the electron microscope images. The largest diameter of each pore in the primary particle is recorded in the microscope image, and the mean value is used as the average particle size D.

[0204] Determination of the mean particle size D' of the primary particles of precursor: After imaging with a scanning electron microscope (ZEISS Sigma-02-33, Germany, 500x magnification), 200 to 600 primary particles of the precursor material with complete shape and no occlusion are randomly selected from the electron microscope images. The largest diameter of each pore in the primary particle is recorded in the microscope image, and the average value is used as the mean particle size D'. 5) Testing of secondary particle size

[0205] Testing of the Dv50 of secondary particles of the active material of a positive electrode: According to GB / T 19077-2016, a laser diffraction method for determining the particle size distribution, 0.1 g to 0.13 g of the active material sample from a positive electrode is weighed into a 50 ml beaker, 5 g of anhydrous ethanol is added, a magnetic stir bar approximately 2.5 mm long is inserted, and the beaker is sealed with cling film. The samples are subjected to ultrasonic treatment for 5 minutes and then transferred to a magnetic stirrer, where they are stirred at 500 rpm for more than 20 minutes. Two samples are taken from each product batch for testing. The test is performed using a Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd., UK.Here, Dv90 is the particle size corresponding to a cumulative volume fraction of 90% for the secondary particles of the active material of a positive electrode, Dv50 is the particle size corresponding to a cumulative volume fraction of 50% for the secondary particles of the active material of a positive electrode, and Dv10 is the particle size corresponding to a cumulative volume fraction of 10% for the secondary particles of the active material of a positive electrode. SPAN = (Dv90 - Dv10) / Dv50.

[0206] Testing of the mean particle size Dv50' of secondary precursor particles: According to GB / T 19077-2016, a laser diffraction method for determining particle size distribution, 0.1 g to 0.13 g of the active material sample from a positive electrode is weighed into a 50 ml beaker, 5 g of anhydrous ethanol is added, a magnetic stir bar approximately 2.5 mm long is inserted, and the beaker is sealed with cling film. The samples are subjected to ultrasonic treatment for 5 minutes and then transferred to a magnetic stirrer, where they are stirred at 500 rpm for more than 20 minutes. Two samples are taken from each product batch for testing. The test is performed using a Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd., UK. The mean particle size Dv50' is the particle size corresponding to a cumulative volume fraction of 50% of the secondary precursor particles. 6) Examination of the area of ​​the (010) crystal plane

[0207] The area of ​​the (010) crystal plane is measured using an X-ray powder diffractometer (XRD, instrument model: Bruker D8 ADVANCE) using Cu Kα as target material; the voltage and current are 40 kV / 40 mA, the scan angle range is between 5° and 80°, the step size is 0.00836° and the time for each step is 0.3 s. 2. Battery performance tests 1) Testing the discharge capacity

[0208] The battery cells are left at 25°C for 2 hours to ensure their temperature is 25°C. At 25°C, the battery cells are charged at 0.1C until the charging cutoff voltage of 4.25V is reached. Charging then continues at a constant voltage at this cutoff voltage until the current reaches 0.05C. At this point, the charging process is terminated (where C represents the nominal capacity of the battery cell). The battery cells are then left at 25°C for 1 hour. At 25°C, the battery cells are discharged at 0.1C until the discharge cutoff voltage of 2.5V is reached, and the total discharge capacity C0 of the battery cells is recorded. 2) Testing the energy density

[0209] Battery cell capacity test: The battery cell is left at 25°C for 2 hours to ensure a temperature of 25°C. At 25°C, the battery cells are charged at 0.1C until the charging cutoff voltage of 4.25V is reached. Charging then continues at a constant voltage at this cutoff voltage until the current reaches 0.05C. At this point, the charging process is terminated (where C represents the nominal capacity of the battery cell). The battery cells are left at 25°C for 1 hour. At 25°C, the battery cells are discharged at 0.1C until the discharge cutoff voltage of 2.5V is reached. The total discharge capacity C0 and the total discharge energy of the battery cells are recorded.

[0210] Weight measurement of the battery cell: The battery cell is placed on an electronic scale until the weight stabilizes, and the value M0 for the weight of the battery cell is read.

[0211] Calculation of energy density: The energy density of a battery cell is calculated by dividing the discharge energy E0 of the battery cell by the weight M0 of the battery cell. 3) Testing the battery discharge time at 40% SOC

[0212] The battery cell is discharged with a constant current of 0.33C to 2.8 V and left to rest for 30 minutes. It is then charged with a constant current of 0.33C to 4.25 V and subsequently with a constant voltage of 0.05C until the voltage stabilizes. It is again left to rest for 30 minutes. Afterward, it is discharged with a constant current of 0.33C to 2.8 V, at which time the initial capacity C0 is recorded. This is followed by a 30-minute rest period. Then, it is charged with a constant current of 0.33C to 4.25 V and subsequently with a constant voltage of 0.05C until the voltage stabilizes. This is followed by a 30-minute rest period. Finally, it is discharged with a constant current of 0.33C to a state of charge of 0.4 C0 Ah (40%) and left to rest for 60 minutes. Finally, it is discharged with a constant current of 4.5C to 2.8V, and the discharge time is recorded. 4) Testing of cycle stability

[0213] The secondary batteries produced in the implementation and comparison examples are charged with a constant current of 0.5C to a final charging voltage of 4.25V, then recharged with a constant voltage to a current of ≤ 0.05C, allowed to rest for 5 minutes, and then discharged with a constant current of 0.33C to a final discharge voltage of 2.5V, again allowing to rest for 5 minutes. This constitutes one charge-discharge cycle. Following this method, the battery is subjected to the charge-discharge cycle test until the battery capacity decreases to 80%. The number of cycles at this point corresponds to the battery's cycle life at 25°C. III. Analysis of the test results of the execution and comparison examples

[0214] The batteries used in the implementation and comparison examples are manufactured according to the procedure described above, and the various performance parameters are measured. The results are presented in the following tables. Table 1 Serial No. Preparation parameters of precursors for active material of a positive electrode Total molar concentration of metal ions in the mixed salt solution / (mol / L) Molar concentration of manganese (mol / L) Molar concentration of the complexing agent (mol / L) Molar concentration of the precipitant (mol / L) Co-precipitation PH Temperature / °C Time / h Stirring speed / rpm Example 1 2 0,3 6 3 9,1 80 10 300 Example 2 2 0,05 4,5 2,6 9,5 79 8 350 Example 3 2 0,3 6 3 9 80 10 300 Example 4 2 1 5 2,9 9,2 78 9 280 Example 5 2 0,7 5,3 2,8 9,5 78 9 270 Example 6 2 0,05 4,5 2,6 9,7 79 8 350 Example 77 2 0,1 4 2,7 9,6 76 8 380 Example 8 2 1,5 5 1,9 9,8 74 7,8 230 Example 9 2 1,2 4,8 1,8 10 73 7,6 250 Example 10 2 0,05 4,2 1,6 10,2 73 7,2 420 Example 11 2 0,02 3,8 1,5 10,4 72 6,8 460 Example 12 2 0,3 6 3 9,4 80 10 300 Example 13 2 0,3 6 3 9,3 80 10 300 Example 14 2 0,3 6 3 9,1 80 10 300 Example 15 2 0,3 6 3 9 80 10 290 Example 16 2 0,3 6 3 9 80 10 300 Example 17 2 0,3 6 3 9 80 10 300 Example 18 2 0,3 6 3 9 80 10 300 Example 19 2 0,3 6 3 9 80 10 300 Example 20 2 0,3 6 3 9 79 10 300 Example 21 2 0,3 6 3 9 78 10 300 Example 22 2 0,3 6 3 9 80 10 300 Example 23 2 0,3 6 3 9 80 10 300 Example 24 2 0,3 6 3 9 80 9,5 300 Example 25 2 0,3 6 3 9 80 9,7 300 Example 26 2 0,3 6 3 9,2 80 9,9 300 Example 27 2 0,3 6 3 9,5 80 9,9 290 Comparative example 1 2 0,005 6 0,8 11,5 78 9 600 Comparative example 2 2 0,008 5,8 0,82 11,3 80 9,2 580 Comparative example 3 2 1,5 5,6 3,5 9,2 72 0,4 320 Table 2 Serial No. Active material of a positive electrode Positive electrode plate Inner diameter of the secondary pore / µm Inner diameter of the primary pore / µm porosity Primary particle D / nm Secondary particles Dv50 / µm Secondary particles (Dv90-Dv10) / Dv50 Area of ​​the (010) crystal plane / µm 2 Thickness / µm Example 1 0,8 / 3% 500 9 1,3 242 300 Example 2 0,2 / 3% 500 9 1,2 222 300 Example 3 0,8 0,09 5 % 500 9 1,3 270 300 Example 4 2 0,09 8% 500 9 1,35 275 300 Example 5 1 0,09 7 % 500 9 1,4 270 300 Example 6 0,2 0,09 1 % 500 9 1,2 212 300 Example 7 0,1 0,09 1 % 500 9 1,16 210 300 Example 8 0,8 0,09 12 % 500 9 1,12 228 300 Example 9 0,8 0,09 10% 500 9 1,13 225 300 Example 10 0,8 0,09 0,20 % 500 9 1,15 222 300 Example 11 0,8 0,09 0,10 % 500 9 1,18 220 300 Example 12 0,8 0,09 5 % 100 9 1,22 265 300 Example 13 0,8 0,09 5 % 120 9 1,22 265 300 Example 14 0,8 0,09 5 % 300 9 1,22 265 300 Example 15 0,8 0,09 5 % 800 9 1,22 265 300 Example 16 0,8 0,09 5 % 500 3 1,22 260 300 Example 17 0,8 0,09 5 % 500 11 1,22 260 300 Example 18 0,8 0,09 5 % 500 4 1,22 260 300 Example 19 0,8 0,09 5% 500 12 1,22 260 300 Example 20 0,8 0,09 5% 500 9 1,5 252 300 Example 21 0,8 0,09 5% 500 9 0,8 243 300 Example 22 0,8 0,09 5% 500 9 1,3 270 200 Example 23 0,8 0,09 5% 500 9 1,3 270 400 Example 24 0,8 0,05 1% 500 9 1,3 226 300 Example 25 0,8 0,08 2 %% 500 9 1,3 231 300 Example 26 0,8 0,2 5 5,2 %% 500 9 1,3 243 300 Example 27 0,8 0,6 5,5 %% 800 9 1,3 262 300 Comparative example 1 / / / 500 9 1,2 230 300 Comparative example 2 0,05 0,09 0,50 % 500 9 1,18 232 300 Comparative example 3 3 0,09 15 % 500 9 1,09 252 300 Table 3 Serial No. battery Energy density (Wh / kg) Discharge time / s Number of cycles / cycles Example 1 426 142 1221 Example 2 427 126 1230 Example 3 430 158 1600 Example 4 415 158 800 Example 5 418 150 1200 Example 6 422 108 880 Example 7 423 102 920 Example 8 416 138 600 Example 9 419 141 700 Example 10 425 112 900 Example 11 427 116 950 Example 12 429 157 1550 Example 13 428 155 1500 Example 14 427 153 1450 Example 15 426 148 1200 Example 16 426 156 1380 Example 17 426 132 1360 Example 18 426 152 1340 Example 19 426 152 1300 Example 20 428 141 1150 Example 21 425 145 1250 Example 22 360 170 1800 Example 23 500 90 700 Example 24 427 121 1011 Example 25 428 139 1061 Example 26 430 151 1271 Example 27 426 147 952 Comparative example 1 405 100 400 Comparative example 2 407 102 420 Comparative example 3 410 134 450

[0215] Based on the above results, the active materials of the positive electrode in embodiments 1 to 30 have the following general formula: Li a Ni x M1 y Mn z M2 1-x-y-zO2, where M1 and M2 each independently comprise one or more elements from Co, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg, Nb, with 0.8≤a≤1.2, 0.55≤x<1, 0 <y≤0,25, 0≤z≤0,2; das Aktivmaterial einer positiven Elektrode liegt in Form von Sekundärpartikeln vor, die durch Aggregation von Primärpartikeln gebildet werden, wobei die Sekundärpartikel Sekundärporen umfassen, die durch die Zwischenräume zwischen den Primärpartikeln gebildet werden, und der Innendurchmesser der Sekundärporen 0,1 µm bis 2 µm beträgt.

[0216] The morphology of the active material of a positive electrode in embodiment 3 is investigated using scanning electron microscopy (SEM). The results are presented in Fig.Figure 1 shows that the secondary particles comprise secondary pores formed by the spaces between the primary particles. The active materials of the positive electrode in embodiments 1 to 30 comprise secondary particles containing secondary pores formed by the spaces between the primary particles, and the inner diameter of the secondary pores is 0.1 µm to 2 µm.

[0217] As can be seen from the comparison of embodiments 1 to 21 and 24 to 27 with comparative example 1, embodiment 28 with comparative example 4, embodiment 29 with comparative example 7 and embodiment 30 with comparative example 8, it is advantageous that the secondary particles of the active materials of the positive electrode in the embodiments of this application comprise secondary pores formed by the spaces between the primary particles in order to improve the energy density, discharge time and cycle stability of the battery.

[0218] As can be seen from the comparison between embodiments 3 to 21 and comparative examples 2 to 3, as well as between embodiment 28 and comparative examples 5 to 6, controlling the inner diameter of the secondary pores in the embodiments of this application to between 0.1 µm and 2 µm is advantageous for further improving the energy density and cycle stability of the battery. As can be seen from the comparison between embodiments 1, 3 to 5, and embodiment 2, it is advantageous to further reduce the inner diameter of the secondary pores in the active material of a positive electrode to between 0.2 µm and 1 µm in order to simultaneously improve the energy density, discharge time, and cycle stability of the battery.

[0219] As shown in embodiments 3, 8 to 11, the porosity of the active material of a positive electrode is adjusted to between 0.1% and 12%, resulting in a battery with high energy density, long discharge time, and excellent cycle stability. As can be seen from a comparison of embodiments 3, 9 to 11 and embodiment 8, further control of the porosity of the active material of a positive electrode to between 0.1% and 10% is advantageous for further improving the energy density and cycle stability of the battery.

[0220] As shown in embodiments 3, 12 to 15, the average particle size D of the primary particles is adjusted to between 100 nm and 800 nm, resulting in a battery with high energy density, long discharge time, and excellent cycle stability. As can be seen from a comparison of embodiments 3, 12 to 14, and embodiment 15, further control of the average particle size D of the primary particles to between 100 nm and 500 nm is advantageous for further improving the energy density, discharge time, and cycle stability of the battery.

[0221] As shown in embodiments 3, 16 to 19, the Dv50 of the secondary particles is adjusted to 3 µm to 12 µm to give the battery high energy density, long discharge time, and excellent cycle stability. As can be seen from the comparison of embodiments 3, 16 to 18 and embodiment 19, further control of the Dv50 of the secondary particles to 3 µm to 11 µm is advantageous for further improving the cycle stability of the battery.

[0222] As can be seen from embodiments 3, 20 to 21, the SPAN value of the secondary particles is set to 0.8 to 1.5 to give the battery a high energy density, a long discharge time and excellent cycle stability.

[0223] As can be seen from embodiments 3, 22 to 23, the thickness of the positive electrode film layer is set to 200 µm to 400 µm in order to achieve a high energy density, long discharge time and excellent cycle stability of the battery.

[0224] As can be seen from the comparison between embodiment 3 and embodiment 1, the primary particles have primary pores, which has a positive effect on the energy density, discharge time, and cycle stability of the battery. As shown in embodiments 3, 24 to 27, the inner diameter of the primary pores of the primary particles is set to 0.05 µm to 0.6 µm, so that the battery has a high energy density, a long discharge time, and excellent cycle stability. A comparison of embodiments 3, 25 to 26 with embodiments 24, 27 shows that further control of the inner diameter of the primary pores of the primary particles to 0.08 µm to 0.2 µm is advantageous to further improve the energy density, discharge time, and cycle stability of the battery.

[0225] It should be noted that this application is not limited to the embodiments described above. The embodiments described above serve only as examples. All embodiments that, within the scope of the technical concept of this application, have essentially the same structure and achieve the same effect are covered by the scope of protection of this application. Furthermore, without deviating from the essence of this application, various modifications of the embodiments that are obvious to a person skilled in the art, as well as other configurations formed by combining parts of the embodiments, are also included in the scope of protection of this application. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] CN 202310473119

[0001] Cited non-patent literature

[0000] GB / T 24586 [0082, 0201] GB / T 19077-2016 [0087, 0090, 0115, 0205, 0206] GB / T 19587-2017

[0118] GB / T 19587-2017 “Determination of the specific surface area of ​​solids by gas adsorption using the BET method

[0202]

Claims

[1] Active material of a positive electrode, characterized by , that the active material of a positive electrode has the following general formula: Li a Ni x M1 y Mn z M2 1-x-y-z O2, where M1 and M2 each independently contain one or more of the following elements: Co, Al, B, Zr, Sr, Y, Sb, W, Ti, Mg and Nb, 0.8≤a≤1.2, 0.55≤x<1, 0 <y≤0,25 und 0≤z≤0,2; The active material of a positive electrode is in the form of secondary particles formed by the aggregation of primary particles, the secondary particles comprising secondary pores formed by the spaces between the primary particles, and the inner diameter of the secondary pores being 0.1 µm to 2 µm. [2] Active material of a positive electrode according to claim 1, characterized by, that the ratio of the shortest distance between the secondary pore and the surface of the secondary particles to the Dv50 of the secondary particles is 1 / 5 to 3 / 5, optionally 3 / 10 to 1 / 2. [3] Active material of a positive electrode according to claim 1 or 2, characterized by , that at least some of the primary particles also have primary pores with an inner diameter of 0.05 µm to 0.6 µm, optionally 0.08 µm to 0.2 µm. [4] Active material of a positive electrode according to any one of claims 1 to 3, characterized by , that 0.8≤a≤1.2, 0.8≤x<1.0, 0 <y≤0,1, 0≤z≤0,1, optional: 0,8≤a≤1,2, 0,85≤x≤0,96, 0<y≤0,02, 0≤z≤0,05. [5] Active material of a positive electrode according to any one of claims 1 to 4, characterized by , that the inner diameter of the secondary pores is 0.2 µm to 1 µm. [6] Active material of a positive electrode according to any one of claims 1 to 5, characterized bythat the porosity of the active material of a positive electrode is 0.1% to 12%, optionally 0.1% to 10%. [7] Active material of a positive electrode according to any one of claims 1 to 6, characterized by , that the average particle size D of the primary particles is 100 nm to 800 nm, optionally 100 nm to 500 nm. [8] Active material of a positive electrode according to any one of claims 1 to 7, characterized by , that the Dv50 of the secondary particles is 3 µm to 12 µm, optionally 3 µm to 11 µm. [9] Active material of a positive electrode according to any one of claims 1 to 8, characterized by , that the SPAN value of the secondary particles is 0.8 to 1.5, optionally 0.8 to 1.

3. [10] Active material of a positive electrode according to any one of claims 1 to 9, characterized by , that the area of ​​the (010) crystal plane in the XRD diffraction spectrum of the active material of a positive electrode is 200 µm 2 up to 300 µm 2 , optionally 250 µm 2up to 280 µm 2 amounts. [11] Positive electrode plate, characterized by , that the positive electrode plate comprises a positive current collector and a positive electrode film layer arranged on at least one surface of the positive current collector, wherein the positive electrode film layer comprises the active material of a positive electrode according to any one of claims 1 to 10. [12] Positive electrode plate according to claim 11, characterized by , that the thickness of the positive electrode film layer is 200 µm to 400 µm, optionally 200 µm to 300 µm. [13] Secondary battery, characterized by that it comprises the positive electrode plate according to claim 11 or 12. [14] Electrical appliance, characterized by that it comprises a secondary battery according to claim 13.

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