Battery and the power-consuming device containing the battery

Abstract

Battery characterized in that it comprises a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode material located on at least one surface of the positive electrode current collector, wherein the positive electrode material includes a positive electrode active material, wherein the positive electrode active material comprises an olivine phosphate and a lithium nickel cobalt manganese oxide, wherein the battery satisfies the following condition: 0.004 ≤ a (c / 1.2) ⋅ b ≤ 0.190, where a = a2 - a1, a1 and a2 each represent the peak positions of the (131)-crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 20% and 80% respectively, and the unit is °; where b is the mass fraction of the lithium nickel cobalt manganese oxide in the positive electrode material and is dimensionless; where c is the ratio of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material and is dimensionless; and where b is in the range of 0.01 to 0.50, and the mass fraction of olivine phosphate in the positive electrode material is in the range of 0.46 to 0.95.

Description

[0001] The present application is a divisional application of the patent application with application number CN 202510416073.7, the filing date 03 April 2025 and the title of the invention Battery and power-consuming device containing the battery. Technical field

[0002] The present invention relates to the technical field of batteries, in particular a battery and a power-consuming device containing the battery. State of the art

[0003] Because olivine phosphates contain manganese ions, these materials exhibit a high voltage plateau and good lithium-ion conductivity. However, olivine phosphate has poor ionic conductivity and tends to polarize during the charge-discharge cycle, leading to significant leaching of manganese ions. This results in a deterioration of the performance of olivine phosphate batteries, especially at high temperatures. Content of the invention

[0004] The purpose of the present invention is to overcome the aforementioned shortcomings of the prior art and to provide a battery and a power-consuming device containing the battery in order to reduce the leaching of Mn from the olivine phosphate and to give the battery good high-temperature properties, such as good high-temperature storage performance and good high-temperature cycle performance.

[0005] To achieve the above-mentioned purpose, the present invention provides, in a first aspect, a battery comprising a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode material located on at least one surface of the positive electrode current collector, wherein the positive electrode material includes a positive electrode active material, the positive electrode active material comprising an olivine phosphate and a lithium nickel cobalt manganese oxide, wherein the battery satisfies the following condition: 0.004≤a(c / 1.2)⋅b≤0.190, where a = a2 - a1, a1 and a2 each represent the peak positions of the (131)-crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 20% and 80% respectively, and the unit is °; where b is the mass fraction of the lithium nickel cobalt manganese oxide in the positive electrode material and is dimensionless; where c is the ratio of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material and is dimensionless.

[0006] In a second aspect, the present invention provides a power-consuming device comprising the aforementioned battery.

[0007] Compared to the prior art, the present invention offers the following advantages: By combining the olivine phosphate with the ternary positive electrode material and adjusting the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20%, the mass fraction (b) of the lithium-nickel-cobalt-manganese oxide in the positive electrode material, and the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material, certain relationships are satisfied. This establishes a balance between the polarization of the olivine phosphate, the diffusion barrier of the lithium ions of NCM, and the thermal stability of NCM, leading to an improvement in the high-temperature properties of the battery, such as high-temperature cycle performance and high-temperature storage performance. Specific embodiments

[0008] To better explain the purpose, technical solution, and advantages of the embodiments of the present invention, the technical solution of these embodiments is described clearly and completely below. It is understood that the described embodiments represent only a portion of the embodiments of the present invention and do not encompass all embodiments. All further embodiments that a person skilled in the art in this field could arrive at without inventive effort based on the embodiments described in this invention fall within the scope of protection of the present invention.

[0009] In the present invention, the openly described technical features include both closed technical solutions consisting of the listed features and open technical solutions containing the listed features.

[0010] In the present invention, unless otherwise specified, the stated ranges of values ​​refer to a continuous range that includes the minimum and maximum values ​​as well as every value between these two values. If the range consists of integers, it also includes every integer between the minimum and maximum values ​​of that range. Furthermore, the ranges can be combined when several ranges are specified that describe features or properties. In other words, unless otherwise specified, all ranges disclosed in this document are to be understood as including all subranges contained therein.

[0011] The present invention does not impose any particular restrictions regarding the specific methods for dispersing and stirring.

[0012] Unless a manufacturer is specified for the reagents or devices used in this invention, they are commercially available products. battery

[0013] The present invention provides a battery comprising a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode material located on at least one surface of the positive electrode current collector, wherein the positive electrode material includes a positive electrode active material, wherein the positive electrode active material comprises an olivine phosphate and a lithium nickel cobalt manganese oxide (NCM), wherein the battery satisfies the following condition: 0.004≤a(c / 1.2)⋅b≤0.190, where a = a2 - a1, a1 and a2 each represent the peak positions of the (131)-crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 20% and 80% respectively, and the unit is °; where b is the mass fraction of the lithium nickel cobalt manganese oxide in the positive electrode material and is dimensionless; where c is the ratio of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material and is dimensionless.

[0014] By adding NCM to the olivine phosphate, NCM's high ionic conductivity can be utilized to increase the ion migration rate of the entire material. This results in smoother delithation and lithium intercalation of the olivine phosphate across all voltage plateaus. Simultaneously, the uniformity of delithation and lithium intercalation within the olivine phosphate is improved, the resulting voltage is reduced, polarization of the olivine phosphate is suppressed, and the risk of manganese leaching from the olivine phosphate is lowered. This contributes to improved high-temperature performance of the battery, such as high-temperature storage and cycle performance.Furthermore, thanks to the manganese it contains, NCM exhibits good structural stability, ensuring that it can stably exert its inhibitory effect on the polarization of olivine phosphate during the charge-discharge cycle.

[0015] The diffraction peak of the (131) crystal plane is a characteristic peak for the olivine phosphate. The peak position corresponds to the distance between the crystal planes. The inventor found that the peak position of the (131) crystal plane in the XRD diagram of the positive electrode sheet changes at different states of charge (SOC) of the battery when the structure of the olivine phosphate becomes unstable, particularly at a state of charge of 80% and 20%. The difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of 80% and 20% reflects the stability of the structure of the olivine phosphate. The smaller this value, the smaller the structural changes of the olivine phosphate during the charging and discharging process, which signifies higher structural stability.However, excessive stability of the olivine phosphate structure and excessive crystallinity negatively affect the development of the capacity.

[0016] The value of the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20% can be regulated by adjusting the type of carbon source in the carbon coating material of the olivine phosphate, the calcination temperature, the holding time and the heating rate during the carbon coating process, as well as the type of doping elements in the olivine phosphate.

[0017] The present invention does not specify a method for determining the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a battery state of charge (SOC) of 80% and 20%. Those skilled in the art can determine the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a battery state of charge (SOC) of 80% and 20% using conventional technical methods. By way of example, the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a battery state of charge (SOC) of 80% and 20% can be determined as follows: The battery is discharged at 0.33 C to 2.5 V, then charged at 0.33 C to 4.25 V, then discharged at 0.33 C to 2.5 V, with the discharge capacity recorded as C1; charging at 0.33 C brings the state of charge to 0.2 times C1, which is referred to as 20% SOC; under an inert atmosphere, the positive electrode sheet is extracted and subjected to an XRD examination, recording the peak angle of the (131) crystal plane, i.e. a1;

[0018] The battery is discharged at 0.33 C to 2.5 V, then charged at 0.33 C to 4.25 V, then discharged at 0.33 C to 2.5 V, with the discharge capacity recorded as C1; charging at 0.33 C brings the state of charge to 0.8 times C1, which is referred to as 80% SOC; under an inert atmosphere, the positive electrode sheet is extracted and subjected to an XRD test, recording the peak angle of the (131) crystal plane, i.e. a2;

[0019] The difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet is then calculated at a state of charge (SOC) of the battery of 80% and 20%;

[0020] The specific test conditions for the XRD test are as follows: Cu target, scan voltage 40 kV, current 40 mA, scan range 5 to 80°, scan speed 5° / min; the XRD test is calibrated using an in-situ silicon marking method; the Ultima IV model from Rigaku (Japan) can be used as the XRD device;

[0021] In the XRD diagram, the diffraction peak at a diffraction angle 2θ of 35.5 ± 0.5° corresponds to the diffraction peak of the (131) crystal plane.

[0022] The mass fraction (b) of lithium nickel cobalt manganese oxide in the positive electrode material indicates the proportion of NCM in the positive electrode material. The higher this value, the greater the proportion of NCM in the positive electrode material. If the NCM proportion in the positive electrode material is too low, the inhibitory effect of NCM on the polarization of the olivine phosphate is not clearly noticeable; if the NCM proportion in the positive electrode material is too high, this leads to a deterioration of the thermal stability of the entire material system, which in turn adversely affects the high-temperature properties.

[0023] The mass fraction (b) of the lithium nickel cobalt manganese oxide in the positive electrode material can be regulated by adjusting the mass ratio between the olivine phosphate and NCM as well as the proportion of the positive electrode active material in the positive electrode material.

[0024] The present invention does not specify a method for determining the mass fraction (b) of lithium nickel cobalt manganese oxide in the positive electrode material; those skilled in the art can determine the mass fraction (b) of lithium nickel cobalt manganese oxide in the positive electrode material using conventional technical methods. For example, the mass fraction (b) of lithium nickel cobalt manganese oxide in the positive electrode material can be determined by analysis using inductively coupled plasma (ICP), for example: The battery is discharged at 0.33 C to 2.5 V. The positive electrode sheet is removed, then soaked in dimethyl carbonate (DMC), dried, and the positive electrode material is scraped from the positive electrode sheet for energy dispersive spectrometry (EDS) analysis. The morphology and size of the material are observed at 15x magnification. Using EDS spot scanning, the elemental composition and the content (normalized atomic fraction in percent) of particles of different sizes in the field of view are determined. Tests are performed on at least three similar particles to obtain accurate results from parallel samples.Based on this data, the type of material is identified, and the average molar ratio of the individual transition metals in the total transition metal content is determined; this corresponds to the chemical composition of the individual components of the main material of the positive electrode in the electrode sheet. The sample is then subjected to ICP analysis (0.5 g of the scraped powder of the positive electrode material is accurately weighed, dispersed in 20 ml of water, and then 10 ml of nitric acid (HNO3, mass fraction 66%) is added; the mixture is dispersed and heated until the powder of the positive electrode material has completely dissolved, and then made up to 100 ml with water to obtain the solution to be analyzed; the solution to be analyzed is then subjected to ICP analysis. The operating conditions of the ICP apparatus are set as follows: gas flow rate 0.5 l / min, power 1150 W).ICP analysis is performed. The concentrations of the chemical elements in the positive electrode active material (i.e., the specific molar ratios of the chemical elements) are determined. Based on the molar ratios of the various transition metals in the total metal fraction determined from the electrode sheets, and taking into account the actual molar ratios of the metals in different materials determined by EDS, the mass fraction θ of the positive electrode material containing specific metal elements is calculated relative to the total material: θ = ICP molar ratio / EDS molar ratio. The mass fraction of the remaining material types is 1 - θ. The mass ratio of the two positive electrode active materials is determined based on their chemical composition, while simultaneously determining the mass fraction of the individual elements in the olivine phosphate and the lithium nickel cobalt manganese oxide using the methods described above.

[0025] The ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material represents the degree of disorder of the NCM crystal structure. A value that is too high indicates excessive disorder of the NCM crystal structure, leading to a deterioration of the cycle performance and thermal stability of the NCM material. Conversely, a value that is too low indicates excessive order of the NCM crystal structure, increasing the diffusion barrier for lithium ions and negatively impacting the internal resistance of the material.

[0026] The value of the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material can be regulated by adjusting the manganese content in the lithium nickel cobalt manganese oxide, the process parameters in the production of the lithium nickel cobalt manganese oxide (e.g. calcination temperature, holding time, heating rate) and the particle size of the lithium nickel cobalt manganese oxide.

[0027] The present invention does not specify a method for determining the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material. Those skilled in the art can determine the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material using conventional technical methods. By way of example, the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material can be determined as follows: The battery is discharged at 0.33 C to 2.5 V, the positive electrode sheet is removed and soaked in DMC for 60 minutes at room temperature, then removed and dried. The positive electrode material is scraped from the surface of the current collector. The recovered positive electrode material is subjected to an XRD study, recording the intensities of the diffraction peaks corresponding to crystal planes (003) and (104), i.e., I(003) and I(104). Subsequently, the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material is calculated.

[0028] The specific test conditions for the XRD test are as follows: Cu target, scan voltage 40 kV, current 40 mA, scan range 5 to 80°, scan speed 2° / min; the XRD test is calibrated using an in-situ silicon marking method; the Ultima IV model from Rigaku (Japan) can be used as the XRD device;

[0029] In the XRD diagram, the diffraction peak at a diffraction angle 2θ of 18.5 ± 0.3° corresponds to the diffraction peak of the (003) crystal plane, while the diffraction peak at a diffraction angle 2θ of 44.5 ± 0.3° corresponds to the diffraction peak of the (104) crystal plane.

[0030] The difference (a) in the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a battery state of charge (SOC) of 80% and 20%, the mass fraction (b) of the lithium-nickel-cobalt-manganese oxide in the positive electrode material, and the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material influence the high-temperature properties of the battery to varying degrees, such as high-temperature cycle performance and high-temperature storage performance. It is difficult to design a battery with good high-temperature properties, such as both good high-temperature cycle performance and good high-temperature storage performance, by adjusting a single variable.By combining olivine phosphate with NCM and adjusting the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a battery state of charge (SOC) of 80% and 20%, the mass fraction (b) of the lithium nickel cobalt manganese oxide in the positive electrode material, and the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material, the above relationships are satisfied. This establishes a balance between the polarization and capacity development of the olivine phosphate, the lithium ion diffusion barrier of NCM, and the thermal stability of NCM, leading to an improvement in the battery's high-temperature properties, such as high-temperature cycle performance and high-temperature storage performance.The (c / 1,2) power of a appears in the relationship mentioned above; this power relationship indicates a nonlinear coupling between a and c and illustrates the regulatory effect of the NCM crystal structure features on the change in the lattice parameters of the olivine phosphate. This further illustrates the comprehensive influence of the interaction between the crystal structure features and the changes in the lattice parameters on the high-temperature properties of the battery.

[0031] For example, the value of a will be optionally given. (c / 1.2) · b. The following values ​​were chosen: 0.004, 0.006, 0.008, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.100, 0.110, 0.120, 0.130, 0.140, 0.150, 0.160, 0.170, 0.180, 0.190 or an interval formed from any two of the above values.

[0032] In a preferred embodiment, the battery satisfies the following condition: 0.008 ≤ a (c / 1.2) · b ≤ 0.036. The value of a (c / 1.2) ·b is kept within this specific range to achieve a better balance between the polarization and capacity development of the olivine phosphate, the diffusion barrier of the lithium ions of NCM, and the thermal stability of NCM, thus further improving the high-temperature properties of the battery, such as high-temperature cycle performance and high-temperature storage performance.

[0033] In some embodiments, the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20% is in the range of 0.05° to 0.20°, for example at 0.05°, 0.07°, 0.10°, 0.12°, 0.15°, 0.18°, 0.20° or in an interval formed by any two of the above values.

[0034] In one of the preferred embodiments, the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20% is in the range of 0.10° to 0.15°.

[0035] If the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20% is in the range of 0.05° to 0.20°, particularly in the range of 0.10° to 0.15°, the stability of the olivine phosphate is more suitable, leading to an improvement in the properties of the battery, such as high-temperature storage performance and cycle performance.

[0036] In some embodiments, the mass fraction (b) of the lithium nickel cobalt manganese oxide in the positive electrode material is in the range of 0.01 to 0.5, for example 0.01, 0.03, 0.05, 0.07, 0.09, 0.10, 0.20, 0.30, 0.40, 0.50 or in an interval formed by any two of the above values.

[0037] In one of the preferred embodiments, the mass fraction (b) of the lithium nickel cobalt manganese oxide in the positive electrode material is in the range of 0.05 to 0.20.

[0038] If the mass fraction (b) of the lithium nickel cobalt manganese oxide in the positive electrode material is in the range of 0.01 to 0.50, particularly in the range of 0.05 to 0.20, this contributes better to balancing the polarization of the olivine phosphate and the thermal stability of the positive electrode material, thereby improving the high-temperature properties of the battery, such as high-temperature cycle performance and high-temperature storage performance.

[0039] In some embodiments, the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material is in the range of 0.5 to 1.8, for example 0.5, 0.7, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 or in an interval formed by any two of the above values.

[0040] In one of the preferred embodiments, the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material is in the range of 1.0 to 1.5.

[0041] If the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material is in the range of 0.5 to 1.8, particularly in the range of 1.0 to 1.5, the degree of disorder of the NCM material is more optimal, the cycle and thermal stability are better, and the diffusion barrier for lithium ions is lower. Furthermore, the high-temperature properties of the battery, such as high-temperature cycle performance and high-temperature storage performance, are improved.

[0042] In some embodiments, a1 lies in the range of 35.0 to 35.9, for example at 35.0, 35.1, 35.2, 35.3, 35.4, 35.5, 35.6, 35.7, 35.8, 35.9, or in an interval formed by any two of the above values. The magnitude of the a1 value reflects the Mn content in the olivine phosphate. Setting the a1 value within the above-mentioned suitable range not only contributes to improving the energy density of the battery but also ensures a more stable binding of Mn in the lithium-iron-manganese structure.

[0043] In some embodiments, a2 is in the range of 35.2 to 36.0, for example at 35.2, 35.3, 35.4, 35.5, 35.6, 35.7, 35.8, 35.9, 36.0 or in an interval formed from any two of the above values ​​to reduce the risk of Mn leaching from the olivine phosphate.

[0044] In some embodiments, the structural formula of lithium nickel cobalt manganese oxide is: LiNi x Co y Mn z M (1-x-y-z)O2, where 0 < x < 1, 0 < y < 1, 0 < z < 1, 0 ≤ 1 - x - y - z < 1 and x / y is in the range of 4.5 to 7, while M is a doping element selected from at least one of the elements Al, W, Mg, Sr, and Zr. Here, x can be selected from the values ​​0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.87, or an interval formed from any two of the above values; y can be selected from the values ​​0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.12, 0.14, 0.15, or any interval formed by any two of the above values; z can be selected from the values ​​0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, or any interval formed by any two of the above values. In one embodiment, x / y lies in the range from 4.5 to 7, for example, 4.5, 5, 5.5, 6, 6.5, 7, or in any interval formed by any two of the above values.This not only allows the lithium nickel cobalt manganese oxide to maintain a good layer structure, but also reduces the degree of disorder of the lithium nickel cobalt manganese oxide.

[0045] The described lithium nickel cobalt manganese oxide may either contain no coating material or be wholly or partially coated with a coating material on its surface; the present invention does not restrict the type of coating material in the lithium nickel cobalt manganese oxide; for example, the coating material comprises at least one element selected from the following: aluminum (Al), titanium (Ti), tungsten (W), boron (B), phosphorus (P), cobalt (Co), yttrium (Y), and silicon (Si). At the same time, the present invention does not specify the content of coating material in the lithium nickel cobalt manganese oxide.For example, the content of coating material in the lithium nickel cobalt manganese oxide is between 500 and 5000 ppm, for instance 500 ppm, 1000 ppm, 1500 ppm, 2000 ppm, 2500 ppm, 3000 ppm, 4000 ppm, 4500 ppm, 5000 ppm or in an interval formed by any two of the above values.

[0046] In some embodiments, the particle size Dv50 of the lithium nickel cobalt manganese oxide is between 2.5 and 4.5 µm, for example 2.5 µm, 3.0 µm, 3.5 µm, 4.0 µm, 4.5 µm or in an interval formed by any two of the above values.

[0047] The present invention does not specify a method for determining the particle size Dv50 of the lithium nickel cobalt manganese oxide; those skilled in the art can determine the particle size Dv50 of the lithium nickel cobalt manganese oxide using conventional technical methods. By way of example, the particle size Dv50 of the lithium nickel cobalt manganese oxide is determined as follows: The discharged battery is disassembled to obtain the positive electrode sheet. The positive electrode sheet is dried, and 0.1 to 0.2 g of powder from the positive electrode material is removed using a spatula. The collected powder is imaged using a scanning electron microscope (SEM). The dimensions of the lithium nickel cobalt manganese oxide in the positive electrode material powder are measured using SEM images and MEARSURE NANO software. The diagonal line method is used to determine the particle size of the lithium nickel cobalt manganese oxide. After more than 100 samples have been taken, the particle size distribution is determined. The particle size parameter for lithium nickel cobalt manganate is calculated: Dv50.

[0048] The present invention does not specify a manufacturing process for the lithium nickel cobalt manganese oxide mentioned; those skilled in the art can produce the lithium nickel cobalt manganese oxide using conventional technical methods. For example, the manufacturing process for the lithium nickel cobalt manganese oxide mentioned comprises the following steps: After mixing the lithium nickel cobalt manganese oxide precursor with a lithium source, the mixture is sintered, resulting in the lithium nickel cobalt manganese oxide.

[0049] The lithium nickel cobalt manganese oxide precursor mentioned contains Ni, Co, and Mn in the desired stoichiometric ratio (i.e., the ratio of these three elements in the lithium nickel cobalt manganese oxide precursor corresponds to the ratio of these three elements in the resulting lithium nickel cobalt manganese oxide; this also applies analogously to other similar formulations), wherein the lithium nickel cobalt manganese oxide precursor consists of one or more of the oxides, hydroxides, and carbonates of Ni, Co, and Mn. For example, the lithium nickel cobalt manganese oxide precursor mentioned consists of hydroxides of Ni, Co, and Mn.

[0050] The aforementioned lithium nickel cobalt manganese oxide precursor can be produced by methods known in this field, such as coprecipitation, gelation, or solid-state processes. As an example, the production process for the aforementioned lithium nickel cobalt manganese oxide precursor comprises the following steps: The Ni source, the Co source and the Mn source are dispersed in the solvent, resulting in a mixed solution;

[0051] The resulting mixture, a strong alkaline solution, and a complexing agent solution are simultaneously pumped into a reaction vessel equipped with a stirrer. The pH of the reaction solution is adjusted to 10–13, and the temperature in the reaction vessel is set to 25–90 °C. During the reaction, a protective atmosphere of one or more inert gases (e.g., nitrogen or at least one of the inert gases) is introduced. After completion of the reaction, aging, filtration, washing, and vacuum drying yield a hydroxide containing Ni, Co, and Mn, i.e., the lithium nickel cobalt manganese oxide precursor.

[0052] In the production of the aforementioned lithium nickel cobalt manganese oxide precursor, the Ni source used includes, among others, at least one of the following compounds: nickel sulfate, nickel nitrate, nickel chloride, nickel oxalate and nickel acetate; and / or the cobalt source used includes, among other things, at least one of the following compounds: cobalt sulfate, cobalt nitrate, cobalt chloride, cobalt oxalate and cobalt acetate; and / or the Mn source used includes, among others, at least one of the following compounds: manganese sulfate, manganese nitrate, manganese chloride, manganese oxalate and manganese acetate; and / or the base contained in the strong alkaline solution used comprises at least one of the following substances: sodium hydroxide and potassium hydroxide; and / or the complexing agent solution used includes, among other things, ammonia water.

[0053] In the production of the aforementioned lithium nickel cobalt manganese oxide precursor, the amounts of the Ni source, Co source and Mn source used can be chosen such that the following condition is met: Molar amount of element Ni: Molar amount of element Co: Molar amount of element Mn = (0.55 to 0.95):(0.03 to 0.15):(0.1 to 0.4).

[0054] In the production of the aforementioned lithium nickel cobalt manganese oxide, the Li source used includes, among others, at least one of the following compounds: lithium oxide (Li2O), lithium phosphate (Li3PO4), lithium dihydrogen phosphate (LiH2PO4), lithium acetate (CH3COOLi), lithium hydroxide (LiOH), lithium carbonate (Li2CO3) and lithium nitrate (LiNO3).

[0055] In the production of the aforementioned lithium-nickel-cobalt-manganese oxide, the ratio of the amount of lithium used to the precursor of the ternary material satisfies the following condition: Molar amount of element Li: Sum of the molar amounts of the elements Ni, Co and Mn = (1 to 1.05):1.

[0056] The mixing of the lithium nickel cobalt manganese oxide precursor with the lithium source can be carried out in a ball mill or a high-speed mixer.

[0057] In the production of lithium nickel cobalt manganese oxide using the lithium nickel cobalt manganese oxide precursor, sintering takes place in an inert atmosphere, for example in a nitrogen, helium or argon atmosphere.

[0058] When producing lithium nickel cobalt manganese oxide using the lithium nickel cobalt manganese oxide precursor, the sintering temperature can be set to 700 to 1000 °C and the sintering time to 6 to 9 hours.

[0059] Furthermore, in the production of the lithium nickel cobalt manganese oxide precursor, a specific amount of a dopant source (if available) can be dispersed in the solvent along with the nickel, cobalt, and manganese sources, as required, to obtain the lithium nickel cobalt manganese oxide precursor. The dopant source can be selected from at least one of the following: aluminum, tungsten, magnesium, strontium, zirconium, etc., to obtain the lithium nickel cobalt manganese oxide with a specific dopant content.

[0060] During the production of lithium nickel cobalt manganese oxide, it can be coated as required. Specifically, a dry process (high-temperature solid-state process) is used in which the coating material is applied to the surface of the lithium nickel cobalt manganese oxide, so that the surface of the lithium nickel cobalt manganese oxide is partially or completely covered with a coating layer formed by the coating material. For example, the coating layer contains at least one of the following elements (hereinafter referred to as the "coating element"): aluminum (Al), phosphorus (P), silicon (Si), titanium (Ti), tungsten (W), boron (B), cobalt (Co), or yttrium (Y).

[0061] In some embodiments, the olivine phosphate comprises at least one of the following: a lithium manganese iron phosphate and a doped lithium manganese iron phosphate.

[0062] In some embodiments, the manganese content in the olivine phosphate is in the range of 60% to 85% relative to the total proportion of transition metals, for example 60%, 65%, 70%, 75%, 80%, 85%, or in an interval formed from any two of the above values.

[0063] In some embodiments, the average primary particle size of the olivine phosphate is in the range of 80 to 200 nm, for example 80 nm, 100 nm, 120 nm, 140 nm, 160 nm, 180 nm, 200 nm or in an interval formed by any two of the above values.

[0064] It should be noted that the average primary particle size of the olivine phosphate in the positive electrode material described in this application can be determined as follows: The positive electrode sheet is removed from the battery, then immersed in dimethyl carbonate (DMC), dried, and the positive electrode material is scraped from the positive electrode sheet for EDS spectral analysis. Under magnification, particles of the olivine phosphate and the layered lithium nickel cobalt manganese oxide are identified by spot scanning. Under a scanning electron microscope at 30,000x magnification, three areas of the olivine phosphate are selected to capture the particle morphology. The diagonal length of the primary olivine phosphate particles is measured using the Nanomeasurer software.Eighty particles of the sample are examined, and the results from the three areas are statistically evaluated to determine the average primary particle size of the olivine phosphate.

[0065] In some embodiments, the chemical formula of lithium manganese iron phosphate is LiMn₂ d Fe 1-dPO4, where 0 < d < 1. d can be set to 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, 0.99, or an interval formed by any two of the above values. The described lithium manganese iron phosphate can be present with or without a dopant; the present invention does not specify the type of dopant in the lithium manganese iron phosphate; by way of example, this dopant comprises, among others, at least one of the elements V, W, Ti, and Mg. At the same time, the present invention does not specify any limitations regarding the dopant content in the lithium manganese iron phosphate; by way of example, the dopant content in the lithium manganese iron phosphate is 500 to 2000 ppm.The described lithium manganese iron phosphate may either contain no coating material or be wholly or partially coated on its surface with a coating material; the present invention does not restrict the type of coating material in the lithium manganese iron phosphate; for example, the coating material comprises at least one of graphene and carbon nanotubes. At the same time, the present invention does not specify the content of coating material in the lithium manganese iron phosphate. By way of example, the content of coating material in the lithium manganese iron phosphate is 1.5 to 2.5 wt.%, for example 1.5 wt.%, 1.8 wt.%, 2 wt.%, 2.2 wt.%, 2.5 wt.%, or lies within an interval formed by any two of the above-mentioned values.

[0066] The present invention does not specify a manufacturing process for the olivine phosphate mentioned; those skilled in the art can produce the olivine phosphate using conventional technical methods. For example, the manufacturing process for the olivine phosphate mentioned comprises the following steps: The manganese source, the iron source, the phosphorus source and the lithium source, as well as a solvent, are mixed and reacted at 140-160 °C for 8 to 12 hours, producing an olivine phosphate precursor; The obtained olivine phosphate precursor is dispersed together with a carbon source in a solvent; the resulting mixture is spray-dried and then calcined under a protective atmosphere, yielding the olivine phosphate.

[0067] For example, the manganese source used in the production of the aforementioned olivine phosphate includes at least one of the following compounds: manganese tetraoxide, manganese nitrate, manganese carbonate, manganese oxalate, manganese sulfate, manganese chloride and manganese acetate.

[0068] For example, the iron source used includes at least one of the following compounds: iron(II) sulfate, iron phosphate, iron(II) phosphate, iron hydroxide, iron(II) hydroxide, iron carbonate, iron(II) carbonate, iron acetate, iron(II) acetate, iron trioxide, iron(III) oxide, iron(II) oxalate and iron oxalate.

[0069] Examples of phosphorus sources used include at least one of the following compounds: phosphoric acid, lithium dihydrogen phosphate, lithium phosphate, diammonium hydrogen phosphate and ammonium phosphate.

[0070] For example, the lithium source used includes at least one of the following compounds: lithium hydroxide, lithium dihydrogen phosphate, lithium phosphate, lithium carbonate, lithium nitrate, lithium oxalate, lithium citrate and lithium acetate.

[0071] For example, the solvent used includes water.

[0072] For example, the carbon source used includes at least one of the following substances: glucose (GLC), sucrose, polyethylene glycol (PEG), and polyvinyl alcohol. For example, the molar ratio of the manganese source, iron source, and phosphorus source used in the production of the aforementioned lithium manganese iron phosphate precursor is (0.6 to 0.85):(0.15 to 0.4):(1.02 to 1.05).

[0073] For example, the protective atmosphere is an inert atmosphere, such as nitrogen.

[0074] For example, the calcination temperature can optionally be between 550 and 680 °C, e.g. 550 °C, 600 °C, 650 °C, 680 °C, or it can be in an interval formed by any two of the values ​​mentioned above.

[0075] For example, the calcination time is 4 to 10 hours, for instance 6 hours, or lies in an interval formed from any two of the values ​​mentioned above.

[0076] In the production of the aforementioned olivine phosphate, a starting material for doping can also be used; for example, when the olivine phosphate precursor and the carbon source are dispersed in a solvent, the starting material for doping can also be added and dispersed together; subsequently, spray drying and calcination under a protective atmosphere are carried out, yielding the olivine phosphate. The starting material for doping can, by way of example, include at least one of the following sources: V source, W source, Ti source, and Mg source.

[0077] In some embodiments, the mass fraction of olivine phosphate in the positive electrode material is in the range of 0.46 to 0.95, for example 0.46, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95 or in an interval formed by any two of the above values.

[0078] In some embodiments, the mass fraction of the positive electrode active material in the positive electrode material is 0.95 to 0.985, for example 0.950, 0.965, 0.970, 0.980, 0.985, or lies in an interval formed by any two of the above values.

[0079] In addition to the positive electrode active material mentioned above, the positive electrode material also contains a conductive agent for the positive electrode and a binding agent for the positive electrode.

[0080] The conductive material of the positive electrode serves to establish electrical conductivity. Any conductive material can be used, provided it has suitable electrical conductivity and does not cause any significant adverse chemical changes in the battery. For example, the conductive material of the positive electrode includes at least one of the following substances: carbon nanotube, carbon black, graphite, carbon fiber, activated carbon, mesoporous carbon, fullerene, etc., where carbon fiber includes, for example, carbon nanofiber, etc., and carbon black includes, for example, SP (Super P, hereinafter synonymous), acetylene carbon black, Ketjen carbon black, etc.

[0081] In some embodiments, the mass fraction of said conductive medium of the positive electrode in said positive electrode material is 0.01 to 0.04, for example 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040 or lies in an interval formed by any two of the above values.

[0082] The positive electrode binder serves to improve the adhesion between the particles of the positive electrode active material, as well as the adhesion between the positive electrode active material and the positive electrode current collector. Any binder can be used without special restrictions, provided it has suitable bonding properties and does not cause any significant adverse chemical changes in the battery. For example, the positive electrode binder includes a fluorinated polyolefin binder, such as polyvinylidene fluoride (PVDF), vinylidene fluoride copolymers, or their modified derivatives (e.g., modified with carboxylic acid, acrylic acid, acrylonitrile, etc.).

[0083] In some embodiments, the mass fraction of said binder of the positive electrode in said positive electrode material is 0.01 to 0.04, for example 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040 or lies in an interval formed by any two of the above values.

[0084] The positive electrode material can be located either on one side of the positive electrode current collector or on both sides of the positive electrode current collector.

[0085] The present invention is not subject to any particular limitations with regard to the positive electrode current collector, as long as it is conductive and does not cause any adverse chemical changes in the battery. For example, aluminum, nickel, titanium, stainless steel, or burnt carbon can be used; alternatively, aluminum or stainless steel can be used whose surface has been provided with one of the following surface treatments: carbon, nickel, titanium, silver, etc.

[0086] The positive electrode sheet of the present invention can be produced using methods customary in this field. For example, the positive electrode active material, the conductive element of the positive electrode, and the binder of the positive electrode are dispersed in a solvent to obtain a positive electrode paste. The positive electrode paste is then applied to at least one side of the positive electrode current collector. After further steps such as drying, rolling, cutting, etc., the positive electrode sheet is obtained. The solvent used to produce the positive electrode paste includes, among other things, N-methyl-2-pyrrolidone (NMP) and deionized water. battery

[0087] The present invention further provides a battery comprising a positive electrode sheet, a negative electrode sheet and an electrolyte solution.

[0088] The negative electrode sheet of the present invention comprises a negative electrode current collector and a negative electrode material arranged on at least one surface of the negative electrode current collector, wherein the negative electrode material includes a negative electrode active material.

[0089] The present invention is not subject to any particular limitations with regard to the negative electrode active material. By way of example, the negative electrode active material comprises at least one of the following substances: natural graphite, synthetic graphite, mesophase carbon microsphere (MCMB), hard carbon, soft carbon, silicon, SiO₂ f (0 < f < 2, e.g. f = 1), silicon carbide and Li4Ti5O 12 .

[0090] In some embodiments, the negative electrode active material comprises graphite, wherein the average particle diameter of the graphite is 8 to 13 µm, for example 8 µm, 9 µm, 10 µm, 11 µm, 12 µm, 13 µm or lies in an interval formed by any two of the above values.

[0091] The present invention does not specify a method for determining the average particle diameter of the graphite; those skilled in the art can determine the average particle diameter of the graphite using conventional technical methods. By way of example, the average particle diameter of the graphite is determined as follows: A discharged secondary battery is disassembled, the powder is scraped off the recovered negative electrode sheet and then tested according to test method D50 of the Chinese standard GB / T 24533-2019.

[0092] In some embodiments, the mass fraction of the negative electrode active material in the negative electrode material is 0.93 to 0.98, for example 0.93, 0.95, 0.97, 0.98, or lies in an interval formed by any two of the above values.

[0093] The described negative electrode active material layer may also contain a conductive agent of the negative electrode and / or a binding agent of the negative electrode.

[0094] The conductive material of the negative electrode serves to establish electrical conductivity. Any conductive material can be used, provided it has suitable electrical conductivity and does not cause any significant adverse chemical changes in the battery. For example, the conductive material of the negative electrode includes at least one of the following substances: carbon nanotube, carbon black, graphite, carbon fiber, activated carbon, mesoporous carbon, fullerene, etc., where carbon fiber includes, for example, carbon nanofiber, etc., and carbon black includes, for example, SP, acetylene carbon black, Ketjen carbon black, etc.

[0095] In some embodiments, the mass fraction of said conductive medium of the negative electrode in said negative electrode material is 0.01 to 0.05, for example 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050 or lies in an interval formed by any two of the above values.

[0096] The negative electrode binder serves to improve the adhesion between the particles of the negative electrode active material, as well as the adhesion between the negative electrode active material and the negative electrode current collector. Any binder can be used without special restrictions, provided it has suitable bonding properties and does not cause any significant adverse chemical changes in the battery. For example, the negative electrode binder includes a fluorinated polyolefin binder, such as polyvinylidene fluoride (PVDF), vinylidene fluoride copolymers, or their modified derivatives (e.g., modified with carboxylic acid, acrylic acid, acrylonitrile, etc.).

[0097] In some embodiments, the mass fraction of said binder of the negative electrode in said negative electrode material is 0.01 to 0.05, for example 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050 or lies in an interval formed by any two of the above values.

[0098] The negative electrode material can be located either on one side of the negative electrode current collector or on both sides of the negative electrode current collector.

[0099] The present invention is not subject to any particular limitations with regard to the negative electrode current collector, as long as it is conductive and does not cause any adverse chemical changes in the battery. For example, copper, stainless steel, aluminum, nickel, titanium, or calcined carbon can be used; alternatively, copper or stainless steel whose surface is treated with at least one of the materials carbon, nickel, titanium, silver, etc., or an aluminum-cadmium alloy can be used.

[0100] Various electrolyte solutions suitable for batteries in this field can be used as the electrolyte solution for the present invention. The electrolyte solution in question comprises an electrolyte and a solvent, wherein the electrolyte can typically comprise a lithium salt.

[0101] For example, the lithium salt includes at least one of the following: lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluoro(oxalato)borate (LiDFOB), lithium bis(oxalato)borate (LiBOB), lithium difluorophosphate (LiPO2F2), lithium difluorobisoxalatophosphate (LiDFOP), and lithium tetrafluoro(oxalato)phosphate (LiTFOP). The concentration of the aforementioned electrolyte in the electrolyte solution is optionally adjusted to 0.9 to 2.0 mol / L.

[0102] The solvent may include, for example, at least one of the following: ethylene carbonate (EC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propyl carbonate (PC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), ethyl methyl sulfone (EMS), and diethyl sulfone (ESE). The mass fraction of the aforementioned solvent in the electrolyte solution may optionally be between 0.55 and 0.92.

[0103] Furthermore, the aforementioned electrolyte solution may also contain an additive. For example, the additive may include a film-forming additive for the negative electrode, a film-forming additive for the positive electrode, and an additive that improves certain battery properties, such as an additive to improve high-temperature performance, an additive to improve overcharging behavior, an additive to improve the battery's cold resistance, etc.

[0104] The battery may also include a separator located between the positive and negative electrode sheets. This separator serves to keep the positive and negative electrode sheets apart, preventing a short circuit between them. The separator can be made of various materials suitable for batteries and known in this field. For example, the separator may include at least one of the following materials: polypropylene and polyethylene. Power-consuming device

[0105] The present invention further provides a power-consuming device containing the aforementioned battery. The battery serves as the power source for the power-consuming device.

[0106] A power-consuming device is any device that can utilize electrical energy and convert it into one or more other forms of energy, such as mechanical, thermal, or optical energy. Examples include an electric motor, an electric heater, and an electric light source. Specifically, this can include mobile devices, electric vehicles, electric trains, ships, satellites, and energy storage systems, among others. Mobile devices include, for example, mobile phones, laptops, drones, robotic vacuum cleaners, e-cigarettes, etc. Electric vehicles include, for example, pure electric cars, hybrid vehicles, plug-in hybrid vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.

[0107] The present invention will now be explained in more detail with reference to comprehensive exemplary embodiments. It should be noted that, unless otherwise specified, the sintering processes described below take place in an air atmosphere: Example 1

[0108] This embodiment provides a lithium-ion battery, the manufacturing process of which is as follows: (1) Production of the positive electrode sheet

[0109] Preparation of olivine phosphate (lithium manganese iron phosphate): MnSO4, FeSO4, and H3PO4 are mixed uniformly in a molar ratio of 6:4:10. After adding water, a mixture with a transition metal concentration of 1 M is prepared. Ascorbic acid and LiOH are then added, with the amount of ascorbic acid being 0.2% of the total molar amount of MnSO4, FeSO4, and H3PO4, and the amount of LiOH being 3 times the molar amount of H3PO4. The resulting mixture is stirred at 70 °C for 6 hours, then heated under pressure to 150 °C and allowed to react for 10 hours. After separation of the solid and drying, the resulting powder is dispersed in water, mixed with a carbon source in an amount of 21 wt% of the powder mass, spray-dried and finally calcined under a nitrogen atmosphere at 800 °C for t hour(s), yielding a carbon-coated lithium manganese iron phosphate;

[0110] The values ​​for t and the selection of the carbon source are listed in Table 1.

[0111] Production of lithium nickel cobalt manganese oxide: Nickel acetate, cobalt acetate, manganese acetate, and sodium hydroxide are mixed with water in a molar ratio of 6:1:3:10 and dissolved uniformly; the mixture is allowed to react for 24 hours at 80 °C. After separation of the solid, the precursor, with an average particle size of 3.5 µm, is mixed uniformly with lithium hydroxide in the correct ratio and then calcined for 8 hours at n °C in an air atmosphere, yielding lithium nickel cobalt manganese oxide.

[0112] The values ​​for n are listed in Table 1.

[0113] Production of the positive electrode sheet: The recovered olivine phosphate is mixed with NCM according to the mixing ratio specified in Table 1 and used as the positive electrode active material. The positive electrode active material is mixed with the binder PVDF and the conductive agent SP in a mass ratio of 97:2:1 and dispersed in NMP, resulting in the positive electrode paste. This positive electrode paste is applied to both sides of an aluminum foil, then roll-pressed and cut to size, producing the positive electrode sheet. (2) Production of the negative electrode sheet

[0114] Synthetic graphite with a particle size of 12 µm, serving as the negative electrode active material, is mixed with the conductive agent SP and the binder CMC in a mass ratio of 96.4:1:2.6 and dispersed in deionized water, resulting in a negative electrode paste. This negative electrode paste is applied to both sides of a copper foil; after drying, rolling, and cutting, the negative electrode sheet is obtained. (3) Preparation of the electrolyte solution

[0115] Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) are mixed in a 1:1:1 volume ratio to obtain a mixed organic solvent. The dried lithium salt LiPF6 is then dissolved in this mixed organic solvent to prepare an electrolyte solution with a LiPF6 concentration of 1 mol / L. (4) Production of the separator

[0116] A polyethylene (PE) separator is used. (5) Assembly, Formation

[0117] The positive electrode sheet, the separator, and the negative electrode sheet are stacked sequentially, with the separator positioned between the positive and negative electrode sheets, acting as a separating layer. This assembly is then wound into an uncased cell. The uncased cell is placed in an outer packaging sleeve, filled with electrolyte solution after drying, and undergoes further processing steps such as vacuum sealing, curing, formation, and shaping, resulting in a lithium-ion battery. Examples 2 to 27 and comparative examples 1 to 2

[0118] Both these embodiments and the comparative examples provide a lithium-ion battery whose manufacturing process is similar to that in embodiment 1, the difference being that: In the production of the olivine phosphate lithium manganese iron phosphate, the molar ratios of MnSO4, FeSO4 and H3PO4 are adjusted according to the chemical structural formula of lithium manganese iron phosphate, the chemical structural formula of lithium manganese iron phosphate, the values ​​for t and the selection of the carbon source are listed in Table 1; In the production of lithium nickel cobalt manganese oxide, the ratio between the sum of the molar amounts of nickel acetate, cobalt acetate and manganese acetate and the molar amount of sodium hydroxide is determined, and the molar ratio of nickel acetate, cobalt acetate and manganese acetate is adjusted according to the chemical structural formula of lithium nickel cobalt manganese oxide, the chemical structural formula of lithium nickel cobalt manganese oxide and the values ​​for n are listed in Table 1; The mass ratio between the positive electrode active material (i.e., the main material of the positive electrode), the binder, and the conductive agent in the manufacture of the positive electrode sheet is listed in Table 1. Table 1 Selection of lithium manganese iron phosphate Calcination time (h) Selection of raw materials for carbon coating Selection of lithium nickel cobalt manganese oxide Sintering temperatures (°C) Mass ratio of NCM to olivine phosphate Main material of the positive electrode: binder: conductive medium Example 1 LiMn 0.6 Feb 0.4 PO4 7,8 Polyethylene glycol LiNi 0.6 Co 0.1 Mr 0.3 O2 860 14:83 97:2:1 Example 2 8,8 Polyethylene glycol 820 15:82 97:2:1 Example 3 LiMn 0.6 Feb 0.4 PO4 6 Polyethylene glycol LiNi 0.6 Co 0.1 Mr 0.3 O2 890 12:85 97:2:1 Example 4 7,2 Polyethylene glycol 810 11:86 97:2:1 Example 5 8,5 Polyethylene glycol 910 19:78 97:2:1 Example 6 7 Polyethylene glycol 860 5:92 97:2:1 Example 7 7 Polyethylene glycol 820 21:76 97:2:1 Example 8 9 Polyethylene glycol 820 12:85 97:2:1 Example 9 LiMn 0.4 Feb 0.6 PO4 5,8 Polyethylene glycol 880 15:82 97:2:1 Example 10 7,5 Polyethylene glycol 800 8:89 97:2:1 Example 11 LiMn 0.6 Feb 0.4 PO4 7 Polyethylene glycol 920 18:79 97:2:1 Example 12 6,5 Polyethylene glycol 830 4:94 98:1:1 Exe 8,5 Polyethylene glycol 880 21:77 98:1:1 Example 13 Example 14 8,4 Polyethylene glycol 860 5:93 98:1:1 Example 15 6,2 Polyethylene glycol LiNi 0.7 Co 0.1 Mr 0.2 O2 860 19:79 98:1:1 Example 16 4,2 Polyethylene glycol LiNi 0.6 Co 0.1 Mr 0.3 O2 780 2:95 97:2:1 Example 17 9,8 Polyethylene glycol 940 46:51 97:2:1 Example 18 5 Polyethylene glycol 750 38:59 97:2:1 Example 19 9,5 Polyethylene glycol 950 31:66 97:2:1 Example 20 4,5 Polyethylene glycol 760 1:96 97:2:1 Example 21 5,5 Polyethylene glycol 940 50:47 97:2:1 Example 22 7,8 Sugar 1000 11:86 97:2:1 Example 23 LiMn 0.6 Feb 0.4 PO4 10 Polyethylene glycol LiNi 0.6 Co 0.1 Mr 0.3 O2 920 25:72 97:2:1 Example 24 9,2 Polyethylene glycol 920 14:83 97:2:1 execution 4 Polyethylene glycol 800 12:85 97:2:1 Example 25 Example 26 3,2 Polyethylene glycol 720 0.8:96.2 97:2:1 Example 27 11,5 Polyethylene glycol 700 53:44 97:2:1 Comparative example 1 LiMn 0.6 Feb 0.4 PO4 7,8 Polyethylene glycol LiNi 0.6 Co 0.1 Mr 0.3 O2 800 1:96 97:2:1 Comparison example 12 4,2 Polyethylene glycol 750 42:55 97:2:1

[0119] Using the method described above, the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a battery state of charge (SOC) of 80% and 20%, the mass fraction (b) of the lithium-nickel-cobalt-manganese oxide in the positive electrode material, and the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material were determined for the various embodiments and comparison examples. The test results are listed in Table 2.

[0120] The lithium-ion batteries of the various embodiments and comparison examples were subjected to a performance test; the test results are listed in Table 2. The specific test method is as follows: High-temperature cycle performance testing: After a 120-minute rest period at 45°C, the lithium-ion battery was charged and discharged as follows: A full charge was performed at a constant current of 1C and constant voltage, with a cutoff voltage of 4.25V and a cutoff current of 0.33C; the battery was then left to rest for 20 minutes and subsequently discharged at a constant current of 1C to 2.5V. The charge and discharge operations described above constitute one cycle; cyclic charge and discharge operations are performed, with the discharge capacity of the first 1C cycle being used as the initial discharge capacity of the first cycle; the ratio of the discharge capacity after 100 1C charge and discharge cycles to the initial discharge capacity of the first cycle is considered the battery's capacity retention rate after 100 high-temperature cycles.

[0121] High-temperature storage performance testing: At 25 °C, a full charge was performed with a constant current of 0.33 C and constant voltage, with a cut-off voltage of 4.25 V and a cut-off current of 0.33 C. The battery was then left to rest for 20 minutes and subsequently discharged to 2.5 V with a constant current of 0.33 C. This constituted one cycle; the cycle was repeated twice, using the capacity (e) from the second cycle. The full charge was performed at 25 °C with a constant current of 0.33 C and constant voltage, with a cut-off voltage of 4.25 V and a cut-off current of 0.33 C. The battery was placed in a climate chamber at 60 °C and left there for 7 days, then transferred to a climate chamber at 25 °C and left to rest for 4 hours. At 25 °C, it was discharged with a constant current of 0.33 C down to 2.5 V, during which the capacitance f was measured.The battery was then fully charged at a constant current of 0.33 C and constant voltage, with a cutoff voltage of 4.25 V and a cutoff current of 0.33 C. It was left to rest for 20 minutes, then discharged at a constant current of 0.33 C to 2.5 V, and the capacity g was determined. f / e is the capacity retention rate after storage, and g / e is the capacity recovery rate after storage. Table 2 a1 a2 a b c a (c / 1.2) ·b Capacity retention rate after 100 cycles at 45 °C and 1 °C (in %) Capacity retention rate after 7 days of storage at 60 °C (in %) Capacity recovery rate after 7 days of storage at 60 °C (in %) Example 1 35,221 35,343 0,122 0,14 1,12 0,020 96,6 94,3 96,3 Example 2 35,334 35,436 0,102 0,15 1,02 0,022 96,2 94,1 95,2 Example 3 35,122 35,271 0,149 0,12 1,28 0,016 95,3 93,2 95,8 Example 4 35,523 35,655 0,132 0,11 1,01 0,020 95,2 94,0 94,3 Example 5 35,890 36,000 0,11 0,18 1,49 0,012 94,5 93,4 95,1 Example 6 35,552 35,687 0,135 0,05 1,12 0,008 95,2 94,5 95,2 Example 7 35,231 35,364 0,133 0,2 1,02 0,036 94,5 92,5 94,9 Example of implementation 35,231 35,323 0,092 0,12 1,02 0,016 94,7 91,2 94,2 8 Example 9 35,112 35,277 0,165 0,15 1,22 0,024 93,7 92,4 93,5 Example 10 35,354 35,477 0,123 0,08 0,91 0,016 94,2 91,0 93,2 Example 11 35,052 35,186 0,134 0,17 1,55 0,013 93,6 91,6 93,5 Example 12 35,123 35,269 0,146 0,04 1,04 0,008 94,5 90,4 92,1 Example 13 35,632 35,742 0,11 0,21 1,21 0,023 93,7 91,1 91,4 Example 14 35,231 35,343 0,112 0,05 1,12 0,006 94,0 91,2 90,2 Example 15 35,298 35,446 0,148 0,19 1,01 0,038 93,5 90,9 89,4 Example 16 35,766 35,959 0,193 0,02 0,85 0,006 91,2 88,3 87,3 Example 17 35,233 35,284 0,051 0,45 1,71 0,006 92,3 89,6 88,4 Example 18 35,631 35,817 0,186 0,38 0,50 0,189 91,1 89,9 87,2 Example 19 35,234 35,296 0,062 0,31 1,79 0,005 93,2 88,2 86,3 Example 20 35,266 35,455 0,189 0,01 0,61 0,004 93,0 87,5 85,9 Example 21 35,231 35,405 0,174 0,5 1,70 0,042 90,9 86,9 84,8 Example 22 34,532 34,677 0,145 0,11 0,62 0,041 91,3 87,0 82,3 Example 23 35,950 36,000 0,05 0,25 1,59 0,005 91,1 86,3 83,8 Example 24 35,029 35,111 0,082 0,14 1,55 0,006 91,8 85,3 81,9 Example 25 35,883 36,081 0,198 0,12 0,75 0,044 91,2 84,5 82,0 Example of implementation 35,232 35,462 0,23 0,008 0,43 0,005 90,3 83,4 81,2 26 Example 27 35,348 35,378 0,03 0,53 0,39 0,170 91,4 84,2 80,4 Comparative example 1 35,231 35,353 0,122 0,01 0,93 0,002 84,2 76,3 75,2 Comparative example 2 35,362 35,554 0,192 0,42 0,51 0,208 81,1 75,5 72,4

[0122] In the batteries manufactured according to the various embodiments of the present invention, the capacity retention rate after 100 cycles at 45 °C with 1 C was ≥ 90%, the capacity retention rate after 7 days of storage at 60 °C was ≥ 83%, and the capacity recovery rate after 7 days of storage at 60 °C was ≥ 80%. This demonstrates that batteries incorporating the positive electrode sheet of the present invention exhibit excellent high-temperature cycle performance and high-temperature storage performance.

[0123] From the comparison of embodiments 1 to 7 with embodiments 8 to 13 and embodiments 14 to 15 with embodiments 16 to 21, it is evident that the battery exhibits improved high-temperature cycle performance and high-temperature storage performance when the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20%, the mass fraction (b) of the lithium nickel cobalt manganese oxide in the positive electrode material, and the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material satisfy the preferred value ranges specified in the present invention.

[0124] A comparison of embodiments 1 to 7 with embodiments 14 to 15 and embodiments 8 to 13 with embodiments 16 to 21 shows that the battery, when the condition 0.008 ≤ a is met, (c / 1.2) · b ≤ 0.036 exhibits improved high-temperature cycle performance and high-temperature bearing performance.

[0125] Comparison examples 1 and 2 show that the high-temperature cycle performance and the high-temperature storage performance of the battery deteriorate when the value of a (c / 1.2)· b exceeds the value range of 0.004 to 0.190, even if the difference (a) of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20%, the mass fraction (b) of the lithium nickel cobalt manganese oxide in the positive electrode material, and the ratio (c) of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material are each within the appropriate value range.

[0126] Finally, it should be noted that the foregoing embodiments serve only to illustrate the technical solution of the present application and do not constitute a limitation of the scope of protection. Even though the present application has been explained in detail with reference to the preferred embodiments, it should be clear to those skilled in the art in this field that modifications or equivalent substitutions can be made to the technical solution of the present application without deviating from the essence and scope of the technical solution of the present application.

[0127] The present invention relates to a battery and a power-consuming device containing the battery, and belongs to the technical field of batteries. The battery of the present invention comprises a positive electrode current collector and a positive electrode material located on at least one surface of the positive electrode current collector, wherein the positive electrode material comprises a positive electrode active material, the positive electrode active material comprising an olivine phosphate and a lithium nickel cobalt manganese oxide.If the difference a of the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 80% and 20%, the mass fraction b of the lithium nickel cobalt manganese oxide in the positive electrode material, and the ratio c of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material satisfy the following relationship: 0.004 ≤ a. (c / 1.2) · b ≤ 0.190, a balance is established between the polarization of LMFP, the diffusion barrier of the lithium ions of NCM and the thermal stability of NCM, resulting in an improvement in the high-temperature properties of the battery, such as high-temperature cycle performance and high-temperature storage performance. 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 202510416073.7

[0001] Cited non-patent literature

[0000] Standard GB / T 24533-2019

[0091]

Claims

A battery characterized in that it comprises a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode material located on at least one surface of the positive electrode current collector, wherein the positive electrode material comprises a positive electrode active material, the positive electrode active material comprising an olivine phosphate and a lithium nickel cobalt manganese oxide, wherein the battery satisfies the following condition: 0.004 ≤ a ( c / 1.2 ) ⋅ b ≤ 0.190 , where a = a 2 - a 1 , a 1 and a 2 each represents the peak positions of the (131) crystal plane in the XRD diagram of the positive electrode sheet at a state of charge (SOC) of the battery of 20% and 80% respectively, and the unit is °; where b is the mass fraction of the lithium nickel cobalt manganese oxide in the positive electrode material and is dimensionless; where c is the ratio of the intensities of the (003) and (104) diffraction peaks in the XRD diagram of the positive electrode material and is dimensionless; and where b is in the range of 0.01 to 0.50, and the mass fraction of olivine phosphate in the positive electrode material is in the range of 0.46 to 0.

95. Battery according to claim 1, characterized in that the battery fulfills the following condition: 0.008 ≤ a(c / 1.2)· b ≤ 0.

036. Battery according to claim 1, characterized in that a is in the range of 0.05° to 0.20°. Battery according to claim 3, characterized in that a is in the range of 0.10° to 0.15°. Battery according to claim 1, characterized in that b is in the range of 0.05 to 0.

20. Battery according to claim 1, characterized in that c is in the range of 0.5 to 1.

8. Battery according to claim 6, characterized in that c is in the range of 1.0 to 1.

5. Battery according to claim 1, characterized in that the olivine phosphate comprises at least one of the following: a lithium manganese iron phosphate and a doped lithium manganese iron phosphate. Battery according to claim 1, characterized in that it fulfills at least one of the following conditions: S1. a1 is in the range of 35.0 to 35.9; S2. a2 is in the range of 35.2 to 36.0; S3. The structural formula of the lithium nickel cobalt manganese oxide is: LiNixCoyMnzM(1-xyz)O2, where 0 < x < 1, 0 < y < 1, 0 < z < 1, 0 ≤ 1 - x - y - z < 1 and x / y is in the range of 4.5 to 7, while M is a dopant selected from at least one of the elements Al, W, Mg, Sr and Zr; S4. In the olivine phosphate, the element manganese constitutes 60% to 85% of the molar content of all transition metals; S5. The average primary particle size of olivine phosphate is in the range of 80 to 200 nm;S6. The Dv50 particle size of lithium nickel cobalt manganese oxide is in the range of 2.5 to 4.5 µm;S7.The battery further comprises a negative electrode sheet, wherein the negative electrode sheet comprises a negative electrode active material, the negative electrode active material comprises graphite, and the average particle diameter of the graphite is 8 to 13 µm. Battery according to claim 1, characterized in that the positive electrode sheet further comprises a conductive means of the positive electrode, wherein the conductive means of the positive electrode comprises at least one of the following components, but is not limited thereto: carbon nanotube, carbon black, graphite, carbon fiber, activated carbon, mesoporous carbon, fullerene, etc., wherein the mass fraction of the conductive means of the positive electrode in the positive electrode material is 0.01 to 0.

04. Battery according to claim 1, characterized in that the positive electrode sheet further comprises a binder of the positive electrode, wherein the binder of the positive electrode comprises, among other things, a fluorine-containing polyolefin binder, wherein the fluorine-containing polyolefin binder comprises, among other things, a polyvinylidene fluoride (PVDF), a vinylidene fluoride copolymer or modifications thereof, wherein the mass fraction of the binder of the positive electrode in the positive electrode material is 0.01 to 0.

04. Power-consuming device, characterized in that it comprises a battery according to any one of claims 1 to 9.