Secondary battery, active cathode material and power-consuming device

Abstract

Secondary battery comprising a cathode foil, wherein the cathode foil comprises an active cathode material, wherein the active cathode material comprises secondary particles, the secondary particles being an agglomerate comprising a plurality of primary particles; wherein the primary particles comprise an active cathode substance; wherein in each of the secondary particles the direction pointing from a center of the secondary particle to its surface is called the X-direction; wherein the X-direction passing through the center of one of the primary particles is called the longitudinal direction; wherein in each of the primary particles the longest axis of the primary particle is called the a-axis; wherein the secondary particles comprise oriented secondary particles; wherein in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1≥60%.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] The present application claims priority over the Chinese patent application filed on July 11, 2024, under No. CN2024109275446 entitled “Secondary battery, active cathode material and power-consuming device”, which is hereby incorporated in full by reference. TECHNICAL AREA

[0002] The present application relates to the technical field of batteries, in particular a secondary battery, an active cathode material and a power-consuming device. STATE OF THE ART

[0003] The foregoing explanations here represent only the technical information for the present application and do not necessarily constitute the state of the art.

[0004] In recent years, technological advancements in secondary batteries have led to the widespread use of lithium-ion batteries in numerous sectors, including power tools, e-bikes, e-motorcycles, electric vehicles, military equipment, aerospace, and energy storage systems such as hydroelectric, thermal, wind, and solar power plants. Lithium-ion batteries play a particularly important role in new energy vehicles. To meet the range, kinetic energy, and lifespan requirements of these new energy vehicles, the energy density, kinetic energy, and cycle life of lithium-ion batteries must be significantly improved. CONTENT OF THE PRESENT INVENTION

[0005] In light of the above problems, the present application provides a secondary battery, an active cathode material, and a current-consuming device. The secondary battery combines high energy density, good kinetic performance, and a long cycle life.

[0006] A first aspect of the present application provides a secondary battery comprising a cathode foil, wherein the cathode foil comprises an active cathode material, wherein the active cathode material comprises secondary particles, wherein the secondary particles are an agglomerate comprising a plurality of primary particles; wherein the primary particles comprise an active cathode substance;

[0007] wherein in each of the secondary particles the direction pointing from a center of the secondary particle to its surface is called the X-direction; wherein the X-direction passing through the center of one of the primary particles is called the longitudinal direction; wherein in each of the primary particles the longest axis of the primary particle is called the a-axis;

[0008] wherein the secondary particles comprise oriented secondary particles; wherein in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1≥60%.

[0009] The active cathode material comprises oriented secondary particles, wherein the oriented secondary particles comprise a certain number of primary particles in which their own a-axis forms a certain angle α1 with the corresponding longitudinal direction.On the one hand, controlling the proportion F1 of the number of primary particles with the above angle α1 in the oriented secondary particles within the above range is advantageous to prevent the penetration of the electrolyte solution into the interior of the grain boundaries of the secondary particles, and it is advantageous to prevent the side reaction between the electrolyte solution and the surface of the active cathode material, and it can improve the actual gram capacity and the cycle lifetime of the active cathode material; on the other hand, controlling the angle α1 within the above angular range can also realize a shorter debedding path for active ions, which contributes to promoting rapid debedding of active ions in the active cathode material during the charging and discharging process, which can improve the actual energy density of the secondary battery and lead to good kinetic performance of the secondary battery.

[0010] In some embodiments, the angle α1 is obtained as follows: in a section passing through the center of the oriented secondary particles, the direction pointing from the center of the oriented secondary particles to the surface of the oriented secondary particles is considered the X-direction, wherein the X-direction passing through the center of the section of a primary particle is considered the longitudinal direction corresponding to the primary particle, wherein the longest axis in the section of the primary particle is referred to as the a-axis, and wherein the angle α1 is obtained on the basis of the angle formed by the a-axis with the corresponding longitudinal direction.

[0011] The statistical analysis of the above parameter α1 can be carried out by taking a section through the center of the oriented secondary particles.

[0012] In some embodiments, F1≥64%.

[0013] By regulating the percentage (F1) of primary particles in which an angle α1 is formed between the a-axis and the longitudinal direction within the oriented secondary particles within the aforementioned range, it is advantageous, on the one hand, to more effectively prevent the penetration of the electrolyte solution into the interior of the grain boundaries of the secondary particles. This more effectively prevents the side reaction of the electrolyte solution with the surface of the active cathode material and more effectively improves the actual gram capacity and cycle lifetime of the active cathode material. On the other hand, it is advantageous to create a shorter debedding path for active ions, which is more conducive to improving the actual energy density and the good kinetic performance of the secondary battery.

[0014] In some embodiments, the percentage of the number of oriented secondary particles among the secondary particles is referred to as P2, where P2≥60% is satisfied.

[0015] In some embodiments, P2≥75%.

[0016] By regulating the percentage (P2) of the number of oriented secondary particles in the secondary particles in the above range, the combined improvement effect of the oriented secondary particles on the high energy density, kinetic power and long cycle life of the secondary battery can be exerted more clearly.

[0017] In some embodiments, the length value of the primary particles along the longitudinal direction is denoted as L, wherein the length value of the primary particles along a direction perpendicular to the longitudinal direction is denoted as W, and wherein the ratio of L to W in the primary particles is denoted as R. L / w is referred to as;

[0018] In the oriented secondary particles, R L / w the primary particles less than or equal to 4.

[0019] By regulating the angle α1, which is formed by the a-axis of the primary particles with the corresponding longitudinal direction, the length ratio R can be changed. L / w The primary particles are regulated in the longitudinal and transverse directions (the transverse direction being a direction perpendicular to the longitudinal direction). This is achieved by regulating the length ratio R. L / W Within the above area, the primary particles can be stacked more densely in the radial direction (X-direction) of the oriented secondary particles, thus increasing the energy density of the battery.

[0020] In some embodiments, the L-value, the W-value, and the RL / W-value are obtained as follows: in a section passing through the center of the oriented secondary particles, the direction from the center of the oriented secondary particles to the surface of the oriented secondary particles is considered the X-direction, wherein the X-direction passing through the center of the section of a primary particle is considered the longitudinal direction corresponding to the primary particle, wherein the L-value is determined based on the length value of the primary particle along the corresponding longitudinal direction, wherein the W-value is determined based on the length value of the primary particle along the direction perpendicular to the corresponding longitudinal direction, wherein an R L / W The value is determined based on the ratio obtained by dividing the L-value by the W-value.

[0021] The statistical analysis of the above parameters L, W and R L / Wcan be carried out by means of a section through the center of the oriented secondary particles.

[0022] In some embodiments, the active cathode material has at least one of the following features:

[0023] In the oriented secondary particles, the RL / W value of the primary particles equals 0. <R L / W ≤4;

[0024] In the oriented secondary particles, the average value of R is L / W of the primary particles 1.5 to 2.5.

[0025] In some embodiments, the active cathode material has at least one of the following features:

[0026] In the oriented secondary particles, the RL / W value of the primary particles equals 0.95 <R L / W ≤4;

[0027] In the oriented secondary particles, the average value of R is L / W of the primary particles 1.5 to 2.0.

[0028] By regulating one or two parameters of the value range of R L / W and the average value of R L / W Within the regions described above, it is possible to regulate the orientation and orientation distribution properties of the primary particles within the oriented secondary particles. This allows for a better balance between preventing electrolyte solution penetration and optimizing the reversible disembedding of active ions, resulting in improved equilibrium between high energy density, cycle performance, and good kinetic performance. The results are favorable for combining high energy density, cycle performance, and good kinetic performance.

[0029] In some embodiments, the length value of the primary particle along the longitudinal direction is designated as L, wherein the distance from the center to the surface of the oriented secondary particles is designated as R; wherein a portion from the center of the oriented secondary particles to a position 2 / 3R from the center is designated as the inner layer, while a portion from a position 2 / 3R from the center to the surface of the oriented secondary particles is designated as the outer layer;

[0030] In the oriented secondary particles, the average value of R is determined. L / W the inner layer as R MI denoted, while the average value of R L / W the outer layer as R MO is denoted, where R MI <R MO .

[0031] In the presence of primary particles with the above angle α1, further control of R leads to MI <R MOto a faster disembedding of the active ions located in the outer layer and outer surface of the secondary particles, which is beneficial to the improvement of the active cathode material and the kinetic performance of the battery.

[0032] In some embodiments, the active cathode material has one or more of the following features:

[0033] In the oriented secondary particles, R MI <1.8 and R MO ≥1.8;

[0034] In the oriented secondary particles, R fulfills L / W the outer layer 1.2≤R L / W ≤4 and R L / W the inner layer 0.95≤R L / W ≤2.8.

[0035] In some embodiments, the active cathode material has one or more of the following features:

[0036] In the oriented secondary particles, 1.3 ≤ R MI <1.8, 1.8≤R MO ≤2.3;

[0037] In the oriented secondary particles, R fulfillsL / W of at least 80% of the primary particles in the outer layer 1.4≤R L / W ≤4, and R L / W of at least 80% of the primary particles in the inner layer 0.95≤R L / W ≤2.0.

[0038] By regulating the combination of the R L / W -value of the inner layer, of the R L / W -Average value of the inner layer (R MI ), of the R L / W -value of the outer layer and the R L / W -Average value of the outer layer (R MO) in the oriented secondary particles in the above manner, it is possible to better control the change in the orientation distribution of the primary particles in the inner and outer layers, in this way the reversible unembedding efficiency of the active ions in the primary particles of the outer layer can be improved, and the prevention of electrolyte solution penetration can also be taken into account, which is more conducive to a better balance of good cycle performance and kinetic performance.

[0039] In some embodiments, the oriented secondary particles of the R L / W -Value of the primary particles from the center of the oriented secondary particles to the surface of the oriented secondary particles successively.

[0040] By R L / wBy controlling the orientation distribution of the primary particles in the oriented secondary particles so that it increases successively from the center to the surface, changes in the orientation distribution of the primary particles in the oriented secondary particles can be better controlled, which contributes to a better improvement in the reversible unembedding efficiency of the active ions of the primary particles in the outer layer, and it can also take into account the prevention of electrolyte solution penetration, which contributes to a better balance between good cycle performance and kinetic performance.

[0041] In some embodiments, the anisotropy index of the angle α1 is expressed as I α1 referred to as the number of primary particles in which the a-axis of the oriented secondary particles forms an angle α1 with the longitudinal direction, where 0.4≤I α1 ≤2.5;

[0042] In a section passing through the center of the oriented secondary particles, the angle α1 of the a-axis, deviating from the corresponding longitudinal direction clockwise, is referred to as a positive angle, while the angle α1 of the a-axis, deviating from the corresponding longitudinal direction counterclockwise, is referred to as a negative angle, where I α1 The ratio of the number of positive angles to the number of negative angles.

[0043] In some embodiments, 0.5 ≤ I α1 ≤2.0.

[0044] The above parameter I α1 can be used to reflect the orientation distribution of the primary particles with angle α1 in the oriented secondary particles, and by controlling I α1Within the above range, it can be achieved that the primary particles have a relatively disordered orientation with angle α1, which is more conducive to preventing the electrolyte solution from penetrating the grain boundaries of the secondary particles and increases the actual gram capacity and cycle lifetime of the active cathode material.

[0045] In some embodiments, the active cathode material has one or more of the following features:

[0046] The active cathode material exhibits D v 50 from 8 µm to 11 µm;

[0047] The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm, where the diameter of the primary particles refers to a maximum length in each direction of the length of the primary particles;

[0048] The particle size distribution parameter SPAN of the active cathode material corresponds to the following formula: SPAN=(D v 90-D v 10) / D v 50, where 1.1≤SPAN≤1.4.

[0049] In some embodiments, the active cathode material has one or more of the following features:

[0050] The active cathode material exhibits D v 50 from 9 µm to 10 µm;

[0051] The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 400 nm to 1500 nm;

[0052] SPAN of the active cathode material meets 1.2≤SPAN≤1.3.

[0053] By regulating D vWithin the above range, 50% of the active cathode material can have a more suitable particle size distribution and thus a more suitable specific surface area, which promotes both the prevention of side reactions and a shorter transfer distance for active ions, allowing the secondary battery to have both good cycle performance and good kinetic performance.

[0054] By regulating the diameter of the primary particles in the oriented secondary particles within the above range, it is advantageous to regulate the occupancy ratio of the active crystal surface of the primary particles, thus further improving the kinetics of the disembedding of the lithium ions of the primary particles.

[0055] By regulating the particle size distribution parameter SPAN of the active cathode material within the above range, it is advantageous that the large and small particles in the active cathode material each have an appropriate volume occupancy ratio, so that the active cathode material exhibits high capacity and simultaneously high powder density, maximizing the volumetric energy density of the cathode side. By matching the particle size to the formed polycrystalline material, the volume energy density of the cathode material can be increased.

[0056] In some embodiments, the active cathode material has one or more of the following features:

[0057] D v 90% of the active cathode material meets 15µm≤D v 90≤18µm;

[0058] D y 10 of the active cathode material meets 4µm≤D v 10≤6µm;

[0059] D n 10 of the active cathode material fulfills D n 10≥2µm.

[0060] In some embodiments, the active cathode material has one or more of the following features:

[0061] D v 90% of the active cathode material meets 16µm≤D v 90≤17µm;

[0062] D v 10 of the active cathode material meets 4.5µm≤D v 10≤5.5µm.

[0063] By regulating D v 90% of the active cathode material in the above area, it is advantageous to control the large particles in the material so that they have a suitable volume ratio, which favors the control of the specific surface area and the suppression of the side reaction.

[0064] By regulating D y10 of the active cathode material within the above range, it is advantageous to control the small particles in the material so that they have a suitable volume ratio, and it is advantageous to improve the pressing density of the material.

[0065] By regulating D n 10 of the active cathode material in the above area, the number of small particles in the material can be controlled so that it lies in a more suitable range, which contributes to controlling a more suitable specific surface and thereby improves the storage life of the battery.

[0066] In some embodiments, the active cathode substance in the oriented secondary particles comprises a layered active lithium ion material.

[0067] In some embodiments, the active cathode substance in the oriented secondary particles comprises a lithium-containing nickel composite oxide.

[0068] The introduction of lithium-containing nickel composite oxides into the active cathode substance of the oriented secondary particles makes the introduction of nickel elements advantageous for increasing the energy density of the active cathode material, in addition to improving the performance of the battery.

[0069] In some embodiments, the molar ratio of nickel element and oxygen element in the lithium-containing nickel composite oxide is designated as Q. Ni / O denoted, where 0.3≤Q Ni / O ≤0.5.

[0070] By controlling the molar ratio of nickel element and oxygen element (Q Ni / O ) in the lithium-containing nickel composite oxide in the above area, the active cathode substance can have a high nickel content, which is more conducive to increasing the energy density of the active cathode material.

[0071] In some embodiments, the oriented secondary particles exhibit one or more of the following features:

[0072] In the oriented secondary particles, 0.4 ≤ Q Ni / O ≤0.5;

[0073] The lithium-containing nickel composite oxide comprises at least one of a Co element (cobalt element) and one M element, wherein the M element is at least one of a Mn element and one Al element;

[0074] The lithium-containing nickel composite oxide comprises a dopant element, where Q Ni / O <0.5, wherein the doping element comprises at least one of the elements Zr, Al, B, Sr and Ca;

[0075] At least one part of the primary particles comprises a particle body and a coating layer arranged on at least part of the surface of the particle body, wherein the particle body comprises a lithium-containing nickel composite oxide, and wherein the coating layer comprises at least one of the elements Zr, Al, B, Sr and Ca.

[0076] By controlling Q Ni / O In the area above, the lithium-containing nickel composite oxide has a high nickel content, which can significantly improve the energy density of the active cathode material.

[0077] The introduction of the cobalt element (Co) into the lithium-containing nickel composite oxide stabilizes the material structure and improves the cycle and multiplication performance of the active cathode material.

[0078] The introduction of manganese (Mn) into lithium-containing nickel composite oxide contributes to cost reduction and improvement of the structural stability of the materials.

[0079] The introduction of aluminum element (Al) into the lithium-containing nickel composite oxide contributes to improving the cycle stability of the materials.

[0080] Modifying lithium-containing nickel composite oxide with one or more of the above dopants and coatings can improve the material's stability, increase its energy density, and extend its cycle life. For example, the structure of lithium-containing nickel composite oxide can be stabilized by bulk-phase doping. The surface of the lithium-containing nickel composite oxide can be coated with a fast-ion conductor, for instance, thereby improving the material's energy density and cycle life.

[0081] In some embodiments, 0.3≤Q is present in the oriented secondary particles. Ni / O ≤0.524. Furthermore, in the oriented secondary particles, the active cathode substance comprises one or more of a lithium nickel cobalt manganese oxide, a lithium nickel cobalt aluminum oxide and a modified form thereof, wherein the modified form comprises one or more of a doping modification and a coating modification, wherein the dopant used for the doping modification comprises at least one of the elements Zr, Al, B, Sr and Ca, while the coating element used for the coating modification comprises at least one of the elements Zr, Al, B, Sr and Ca;

[0082] The molar ratio R Ni / O of the nickel element and the oxygen element in the active cathode substance fulfills 0.4≤R Ni / O ≤0.5.

[0083] In some embodiments, the active cathode material has one or more of the following features:

[0084] The active cathode material exhibits D v 50 from 8 µm to 11 µm, optionally 9 µm to 10 µm.

[0085] The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm, optionally 400 nm to 1500 nm;

[0086] The particle size distribution parameter SPAN of the active cathode material corresponds to the following formula: SPAN=(D v 90-D v 10) / D v 50, where 1.1≤SPAN≤1.4, optionally 1.2≤SPAN≤1.3.

[0087] A ternary active cathode compound with a high nickel content and a modified version thereof can be incorporated into the active cathode compound of the oriented secondary particles. The modification can include one or more doping and coating modifications, which can be used to obtain a ternary active cathode compound with high energy density and long lifetime. The structure of the ternary active cathode compound can be stabilized by bulk-phase doping, and the energy density and cycle lifetime of the material can be improved by applying a fast-ion conductor coating to the surface of the ternary active cathode compound.In combination with the regulation of the angle α1 and F1, the orientation and distribution of the primary particles in the secondary particles of the active cathode material can be regulated. This allows for a balance between preventing the penetration of the electrolyte solution into the interior and optimizing the distance of the lithium ion transfer path, thereby improving the mass energy density and the diffusion kinetics of the lithium ions in the material. This can be achieved by controlling one or more of the parameters D. vBy adjusting the size distribution of the active cathode material, the diameter of the primary particles in the oriented secondary particles, and the particle size distribution parameter SPAN of the active cathode material within the ranges mentioned above, a further combination of the above advantages can be achieved. For example, by regulating the particle size distribution parameter SPAN of the active cathode material within the range mentioned above, it is advantageous to have a suitable volume fraction of large or small particles in the active cathode material, which can further improve the powder compaction density of the material and the volumetric energy density of the cathode foil. By matching the size of the secondary particles to the primary particles, the resulting polycrystalline material can increase the volumetric energy density of the cathode material.Furthermore, a longer cycle life can be achieved by combining doping and coating modification methods in order to improve the bulk phase structure of the material as well as the stability of the surface.

[0088] In some embodiments, the inner layer of the oriented secondary particles has an average value of L less than or equal to 700 nm and the outer layer has an average value of L greater than or equal to 720 nm;

[0089] The length value of the primary particle along the longitudinal direction is denoted as L, where the distance from the center to the surface of the oriented secondary particles is denoted as R; where a portion from the center of the oriented secondary particles to a position 2 / 3R from the center is called the inner layer, while a portion from a position 2 / 3R from the center to the surface of the oriented secondary particles is called the outer layer.

[0090] In the oriented secondary particles, the inner layer has an average value of L less than or equal to 660 nm and the outer layer has an average value of L greater than or equal to 750 nm.

[0091] For the active cathode material, in which the active cathode substance in the oriented secondary particles comprises a lithium-containing nickel composite oxide, it is possible, by controlling the average values ​​of L in the inner and outer layers of the oriented secondary particles in the regions mentioned above, to both equip the outer layer with a faster reversible debedding efficiency of the active ions and to equip the inner layer with a larger angle to better prevent the penetration of the electrolyte solution into the grain boundaries. In this way, the actual energy density, cycle performance, and kinetic performance of the battery can be comprehensively improved.

[0092] In some embodiments, the secondary battery further comprises an anode foil, a separator and an electrolyte solution, wherein the separator is arranged between the cathode foil and the anode foil.

[0093] In some embodiments, the secondary battery is a lithium-ion secondary battery.

[0094] A second aspect of the present application provides an active cathode material.

[0095] In some embodiments, the active cathode material comprises secondary particles, wherein the secondary particles are an agglomerate comprising several primary particles; wherein the primary particles comprise an active cathode substance;

[0096] In each of the secondary particles, the direction pointing from a center of the secondary particle to its surface is called the X-direction; the X-direction passing through the center of one of the primary particles is called the longitudinal direction; and in each of the primary particles, the longest axis of the primary particle is called the a-axis.

[0097] The secondary particles comprise oriented secondary particles; wherein in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1≥60%.

[0098] The cathode foils produced with the above-mentioned active cathode material can be used to manufacture secondary batteries with high energy density, good kinetic performance, and long cycle life. Controlling the orientation angle and the proportion of primary particles within the oriented secondary particles in the active cathode material can prevent the electrolyte solution from penetrating the interior of the secondary particle grain boundaries, thus suppressing the side reaction between the electrolyte solution and the surface of the active cathode material.The actual gram capacity and cycle life of the active cathode material can be improved in this way, and a shorter debedding path for active ions can also be achieved, which helps promote the rapid debedding of active ions during charging and discharging, which can improve the actual energy density of the secondary battery and enable good kinetic performance from the secondary battery.

[0099] In some embodiments, the active cathode material is provided in the secondary battery described in the first aspect of the present application.

[0100] A third aspect of the present application provides a power-consuming device comprising at least one of the secondary battery according to the first aspect and the active cathode material according to the second aspect of the present application.

[0101] Details of one or more embodiments or exemplary embodiments of the present application are illustrated in the accompanying drawings and the following description. Further features, subject matter and advantages of the present application will become apparent from the description, the accompanying drawings and the claims. BRIEF DESCRIPTION OF THE DRAWING

[0102] For a better description and illustration of the embodiments, exemplary embodiments, or examples contained in the present application, reference may be made to one or more of the accompanying drawings. The additional details or examples used to describe the accompanying drawings should not be considered as limiting the scope of any of the disclosed applications, the embodiments, or examples currently described, or the best way of these applications as they are currently understood. Furthermore, in all the accompanying drawings, the same parts are indicated by the same symbols. In the drawings, the following are shown: Fig.Figure 1 is a schematic representation of the parameters associated with oriented secondary particles in an embodiment of the present application, wherein only a part of the section of the primary particles on a two-dimensional section of the oriented secondary particles is shown. Fig. Figure 2 shows experimental results of a section of an oriented secondary particle in an embodiment of the present application. Fig. Figure 3 shows a schematic representation of a battery cell in an embodiment of the present application; Fig. Figure 4 shows a decomposition representation of the in the Fig. 3 battery cell shown in an embodiment of the present application; Fig. Figure 5 shows a schematic representation of a battery module in an embodiment of the present application; Fig.Figure 6 shows a schematic representation of a battery pack in an embodiment of the present application; Fig. 7 is a decomposition representation of the in the Fig. 6 battery packs shown in an embodiment of the present application; Fig. Figure 8 shows a schematic representation of a power-consuming device which uses a secondary battery as a power source in an embodiment of the present application. Reference symbol list:

[0103] 52, electrode assembly; 1, battery pack; 2, upper housing; 3, lower housing; 4, battery module; 5, battery cell; 51, housing; 53, cover plate; 6, power-consuming device. DETAILED DESCRIPTION

[0104] The following describes some embodiments or exemplary embodiments of a secondary battery, an active cathode material, and a current-consuming device of the present application with reference to the accompanying drawings. However, there will be instances where an unnecessarily detailed description is omitted. For example, detailed descriptions of things that are already well known and repeated descriptions of the same structure are omitted. This is to avoid making the following description unnecessarily long and to facilitate understanding by the person skilled in the art. Furthermore, the accompanying drawings and the following description serve to provide the person skilled in the art with a complete understanding of the present application and are not intended to limit the subject matter specified in the claims.

[0105] The "range" disclosed here is defined in terms of a lower bound and an upper bound, with a particular range being defined by selecting a lower bound and an upper bound that establish the limits of that range. Ranges defined in this way can include or exclude end values ​​and can be combined in any way, and each end value can be included or excluded independently and combined in any way; that is, any lower bound can be combined with any upper bound to form a range. For example, if a range of 60-120 and 80-110 is specified for a particular parameter, then a range of 60-110 and 80-120 is to be expected. Furthermore, if the minimum values ​​are specified as 1 and 2, and the maximum values ​​as 3, 4, and 5, then the following ranges can be expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.Unless otherwise specified, the range "ab" denotes any combination of real numbers between a and b, where both a and b are real numbers. For example, the range "0-5" means that all real numbers between 0 and 5 are listed here, and 0-5 is simply a shorthand representation of the combination of these values. Furthermore, stating that a parameter is an integer ≥ 2 is equivalent to stating that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and so on. For example, expressing a parameter as an integer from 2 to 10 is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0106] The present application refers to “more than one”, “a multitude”, etc., which, unless expressly limited, means a number greater than or equal to 2. For example, “one or more” means one or more than or equal to (≥) two. The term “any multiple” refers to any suitable combination of elements, i.e., “any multiple” elements in a manner that is not inconsistent with the present application and with which it can be implemented.

[0107] Unless expressly stated otherwise, all embodiments and optional embodiments of the present application may be combined to form new technical solutions.

[0108] The reference to "exemplarities" in this application means that certain features, structures, or properties described in connection with exemplary embodiments may be included in at least one exemplary embodiment or embodiment of this application. The presence of this term in different places in the description does not necessarily refer to the same exemplary embodiment, nor does it imply a separate or alternative exemplary embodiment that mutually excludes other exemplary embodiments. The person skilled in the art will understand that the exemplary embodiments described herein may be combined with other exemplary embodiments, both expressly and implicitly. References to "portions" are to be understood in the same way.

[0109] The person skilled in the art will understand that the order in which the steps are listed in the methods of each embodiment or exemplary embodiment does not imply any restriction of the implementation process by a strict execution order, and that the detailed order of execution of the steps should be determined by their function and possible internal logic. Unless expressly stated otherwise, all steps of the present application may be performed sequentially or randomly, optionally sequentially. For example, Method M comprises steps (a) and (b), which means that the method may include steps (a) and (b) performed consecutively, or that it may include steps (b) and (a) performed consecutively. Another example is that Method M may also include step (c), which means that step (c) may be added to Method M in any order, e.g.,The procedure M may contain steps (a), (b) and (c), or it may contain steps (a), (c) and (b), or it may contain steps (c), (a) and (b), and so on.

[0110] In the present application, open-ended technical features or solutions are described by the words "contains," "comprises," "includes," etc. Unless otherwise specified, which does not exclude additional elements beyond those listed, it can be assumed that the feature or solution is both a closed feature or solution consisting of the listed elements and an open feature or solution containing additional elements beyond those listed. For example, A, which includes a1, a2, and a3 and, unless otherwise specified, other members or excludes additional members, can be considered both a feature or solution "A includes a1, a2, and a3" or "A is selected from a1, a2, and a3." A feature or program that includes "A not only a1, a2, and a3, but also other members" is also provided.

[0111] In the present application, A (e.g. B), unless otherwise specified, means that B is a non-restrictive example of A.

[0112] In the present application, "optional," "alternatively," and "optionally" mean optional; that is, they refer to one of the two juxtapositions of "with" or "without." If more than one "option" appears in a technical solution, each "option" is independent of the others unless otherwise specified and unless there are contradictions or constraints. Unless otherwise specified, the phrase "optionally includes" in the present application (using the example of "optionally includes") means that the relevant subject matter may or may not be included.

[0113] Unless otherwise specified, the term "and / or" in this application includes any element consisting of two or more listed elements, as well as any and all combinations of the listed elements. "Any and all combinations" include any two listed elements, any number of listed elements, or the combination of all listed elements. For example, "A and / or B" means the group consisting of A, B, and the combination of A and B. "Includes A and / or B" can mean "includes A, includes B, and includes A and B," or "includes A, includes B, or includes A and B," whichever is appropriate to understand depending on the context.

[0114] Phrases such as "their combination", "any combination" or "any combination" in this text include all suitable combinations of two or more of the listed elements.

[0115] The word “suitable” in expressions such as “suitable combination”, “suitable way” or “any suitable way” refers to the fact that the technical solution of the present application is thus feasible.

[0116] Terms such as "preferred," "better," "more advantageous," "recommended," or "more favorable" in this text serve only to describe embodiments or examples with improved performance. It should be understood that these do not constitute a limitation of the scope of protection of the present application. If more than one "preferred" designation appears in a technical solution, each "preferred" designation is independent of the others, unless otherwise specified and provided there are no contradictions or constraints.

[0117] In the present application, expressions such as "furthermore", "moreover", "in particular", "for example", "as", "exemplary" or "for illustration" serve to describe differences in content and are not to be understood as restricting the scope of protection of the application.

[0118] In the present application, as in "first aspect," "second aspect," "third aspect," etc., the terms "first," "second," "third," etc., serve solely descriptive purposes. They are not to be understood as indicating any relative importance, priority, or quantity, nor as implicitly specifying the importance or number of the designated technical features. Furthermore, "first," "second," "third," etc., serve only as a non-exhaustive list and description. They should be understood as not constituting a complete (numerical) limit.

[0119] In the present application, the term "room temperature" generally refers to 4 °C to 35 °C and may refer to 20 °C ± 5 °C. In some embodiments of the present application, room temperature is defined as 20 °C to 30 °C.

[0120] In the present application, the units of the data range are the same for the left and right endpoints if only the right endpoint is followed by a unit. For example, 3 to 5 hours or 3-5 h means that the unit of both the left endpoint is "3" and the right endpoint is "5" h (hour), which has the same meaning as 3h~5h. Furthermore, similar descriptions of other parameters such as temperature, size, etc., are to be understood in the same way.

[0121] The weight or mass of the relevant components mentioned in the embodiments of the present application may refer not only to the content of each component, but may also indicate the ratio of the weight or mass of each component, so that, as long as the content of the relevant components is proportionally increased or decreased in accordance with the embodiments of the present application, they all fall within the scope of the description of the present application. Furthermore, the mass of the embodiment or embodiments of the present application may be a microgram (µg), a milligram (mg), a gram (g), a kilogram (kg), and other units of mass known in the chemical industry. Unless otherwise specified, the mass ratio is equal to the corresponding weight ratio, e.g.,If substance A has a mass of m1 and a weight of W1, and substance B has a mass of m2 and a weight of W2, then the mass ratio m1 / m2 of the two is numerically equal to the corresponding weight ratio W1 / W2.

[0122] In the present application, wt% denotes a weight percentage which is numerically equal to the corresponding mass percentage, unless otherwise specified.

[0123] In the present application, the expressions "greater than or equal to", "greater than or equal to", and the symbol ",≥" have the same meaning and are interchangeable. Likewise, "less than or equal to", "less than or equal to", and the symbol "≤" have the same meaning and are interchangeable. "Greater than" can be expressed synonymously as ">", and "Less than" can be expressed synonymously as "<". Unless otherwise specified, "greater than or equal to" and "≥" in the present application can be understood to also provide the two options "greater than" and "equal to". Unless otherwise specified, "less than or equal to" and "≤" in the present application can also be understood to provide the two options "less than" and "equal to".

[0124] In the present application, exemplary formulations such as "in some embodiments (or exemplary embodiments)" or "in one embodiment (or exemplary embodiment)" include, among others, the following meaning, but are not limited to it: These solutions can be combined in a suitable manner with other solutions to form new technical solutions.

[0125] A common approach for active cathode materials is to use polycrystalline materials in which the secondary particles consist of a multitude of primary particles. For example, in an active lithium-ion material, it is common to obtain secondary particles where the longest axis (a-axis) of the primary particles is essentially aligned with the direction of the secondary particles from the center to the surface. In this case, the kinetics of the active cathode material during lithium ion debedding can be improved by shortening the lithium ion transfer distance.However, due to the overly regular orientation of the primary particles, obvious penetration-like channels form between the primary particles, through which the electrolyte solution can easily penetrate into the interior of the secondary particles, leading to more serious side reactions at the interface, thereby reducing the cycle performance and the actual gram capacity of the active cathode material, which in turn worsens the cycle lifetime of the material.

[0126] In light of this, the present application provides a secondary battery, an active cathode material, and a current-consuming device. The secondary battery combines high energy density, good kinetic performance, and a long cycle life.

[0127] In some embodiments, the secondary battery comprises a cathode foil, the cathode foil comprising an active cathode material, wherein the active cathode material comprises secondary particles, the secondary particles being an agglomerate comprising a plurality of primary particles; wherein in each of the secondary particles the direction pointing from a center of the secondary particle to its surface is referred to as the X-direction; wherein the X-direction passing through the center of one of the primary particles is referred to as the longitudinal direction; wherein in each of the primary particles the longest axis of the primary particle is referred to as the a-axis; wherein the secondary particles comprise oriented secondary particles;where in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1≥60%.;

[0128] A typical secondary battery comprises a cathode foil, an anode foil, an electrolyte solution, and a separator. During charging and discharging, active ions are embedded and unembedded between the cathode and anode foils. The electrolyte acts as an ion conductor between the cathode and anode foils. The separator, located between the cathode and anode foils, primarily serves to prevent a short circuit between the cathode and anode while still allowing the passage of ions.

[0129] In the present application, unless otherwise specified, the electrode foil can be a cathode foil or an anode foil, and the "active material" in the electrode foil refers to a material capable of reversibly embedding and releasing active ions. Unless otherwise specified, "active anode material" means a material used in the anode foil capable of reversibly embedding and releasing active ions, and "active cathode material" means a material used in the cathode foil capable of reversibly embedding and embedding active ions. During the charging of a battery cell or a secondary battery, the active ions are released from the cathode and embedded in the anode by the electrolyte; and during the discharging of a battery cell or a secondary battery, the active ions are released from the anode and embedded in the cathode. The active ions are not specifically limited.In some embodiments, the active ions can include lithium ions. Without limitation, the active ions can be lithium ions. In this case, the battery cell is a lithium-ion battery cell and the secondary battery is a lithium-ion secondary battery.

[0130] In the present application, “polar foil” and “electrode foil” have the same meaning and can be used interchangeably; “active electrode substance” and “active substance” have the same meaning and can be used interchangeably.

[0131] In the present application, unless otherwise specified, the “active electrode material layer” comprises at least one of the active cathode material layers of the cathode foil and one of the active anode material layers of the anode foil, and the active electrode material layer may refer to either the active cathode material layer or the active anode material layer, depending on the specific circumstances. It is understood that the active cathode material layer contains an active cathode substance and the active anode material layer contains an active anode substance. In the present application, “active electrode material layer” may also be abbreviated as “active material layer”.

[0132] Unless otherwise stated, the terms “separator film” and “separator” have the same meaning in this application and can be used interchangeably.

[0133] It is assumed that the "primary particles" and the "secondary particles" are particles that contain the active cathode substance.

[0134] In the present application, the terms "primary particles" and "secondary particles" are known in the technical field. "Primary particles" are understood to be single crystals or single-crystal-like grains. "Secondary particles" refer to particles in an agglomerated state resulting from the aggregation of two or more primary particles. The primary and secondary particles can be readily distinguished experimentally, for example, by SEM images obtained with a scanning electron microscope (SEM).

[0135] A first aspect of the present application provides a secondary battery comprising a cathode foil, wherein the cathode foil comprises an active cathode material, wherein the active cathode material comprises oriented secondary particles.

[0136] In some embodiments, a secondary battery is provided comprising a cathode foil, wherein the cathode foil comprises an active cathode material, wherein the active cathode material comprises secondary particles, wherein the secondary particles are agglomerated particles comprising a plurality of primary particles; wherein the primary particles comprise an active cathode substance;

[0137] In each of the secondary particles, the direction pointing from a center of the secondary particle to its surface is called the X-direction; the X-direction passing through the center of one of the primary particles is called the longitudinal direction; and in each of the primary particles, the longest axis of the primary particle is called the a-axis.

[0138] The secondary particles comprise oriented secondary particles; wherein in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1≥60%.

[0139] For the purposes of this application, the term “X-direction” refers to the direction from the center to the surface of the secondary particles, unless otherwise specified. It is understood that different positions of the secondary particles relative to their center to their surface correspond to different X-directions; each position of the surface of the secondary particles corresponds to a corresponding X-direction thereof.

[0140] For the purposes of this application, the term "longitudinal direction" refers to a direction that passes through both the center of the secondary particles and the center of one of the primary particles, unless otherwise specified. It is understood that different longitudinal directions apply to different primary particles, each primary particle corresponding to its respective longitudinal direction.

[0141] For the purposes of this application, the “a-axis” of the primary particles refers to the longest axis of the primary particles in each direction, unless otherwise specified. Typically, the longest axis in the two-dimensional section of the primary particle can be used as a test result for the length of the a-axis.

[0142] In the present application, unless otherwise specified, the percentage of the number of primary particles in which the a-axis forms an angle α1 with the longitudinal direction among the oriented secondary particles is referred to as F1.

[0143] In the present application, unless otherwise specified, “oriented secondary particles” means a certain number of primary particles with the property that the a-axis of the primary particles forms an angle with the corresponding longitudinal direction. Unless otherwise specified, the angle formed between the a-axis of the primary particles and the corresponding longitudinal direction is referred to as “α1” and may be called the “angle α1”. Unless otherwise specified, the percentage of the number of primary particles in which the a-axis forms an angle α1 with the longitudinal direction among the oriented secondary particles is referred to as “F1”. In the present application, secondary particles are generally referred to as oriented secondary particles if they satisfy 15°≤α1≤45° and F1≥60%.

[0144] The active cathode material comprises oriented secondary particles, wherein the oriented secondary particles comprise a certain number of primary particles in which their own a-axis forms a certain angle α1 with the corresponding longitudinal direction.On the one hand, controlling the proportion F1 of the number of primary particles with the above angle α1 in the oriented secondary particles within the above range is advantageous to prevent the penetration of the electrolyte solution into the interior of the grain boundaries of the secondary particles, and it is advantageous to prevent the side reaction between the electrolyte solution and the surface of the active cathode material, and it can improve the actual gram capacity and the cycle lifetime of the active cathode material; on the other hand, controlling the angle α1 within the above angular range can also realize a shorter debedding path for active ions, which contributes to promoting rapid debedding of active ions in the active cathode material during the charging and discharging process, which can improve the actual energy density of the secondary battery and lead to good kinetic performance of the secondary battery.

[0145] In some embodiments of the present application, the angle α1 can be obtained as follows: in a section passing through the center of the oriented secondary particles, the direction pointing from the center of the oriented secondary particles to the surface of the oriented secondary particles is considered the X-direction, wherein the X-direction passing through the center of the section of a primary particle is considered the longitudinal direction corresponding to the primary particle, wherein the longest axis in the section of the primary particle is referred to as the a-axis, and wherein the angle α1 is obtained on the basis of the angle formed by the a-axis with the corresponding longitudinal direction.

[0146] The statistical analysis of the parameter α1 above can be performed using a cross-section through the center of the oriented secondary particles. In a cross-sectional view through the center of the oriented secondary particles, the cross-section and cross-sectional contour of the oriented secondary particles, as well as the cross-section and cross-sectional contour of the primary particles, can be represented. Unless otherwise specified, the center of the oriented secondary particles can be determined as follows: Based on the cross-sectional contour of the oriented secondary particles, the intersection point between a longest axis and a shortest axis in the cross-section of the oriented secondary particles is assumed to be the center of the oriented secondary particles.

[0147] The parameters associated with the primary particles in the oriented secondary particles can be statistically analyzed using a morphological analysis method with ion-polished sectioning. Alternatively, the secondary particles can be sectioned to form a section substantially through the center of the secondary particles, obtaining a sample with the sectioned surface, and the parameters associated with the primary particles in the section surface of the secondary particles can be further statistically analyzed in conjunction with a microscopic morphological observation method. The section, which passes substantially through the center of the secondary particles, can be obtained using instruments or devices, including, but not limited to, a focused electron beam (FIB) microscope (non-restrictive example: FEI Scios 2HiVac device, etc.).), an ion-section polisher (non-limiting example: IB-09010 CP-type argon ion cross-section polisher, IB-19500CP ion cross-section polisher, etc., from JEOL, Japan), and the like. For the microscopic morphology observation method, instruments or devices may be used, including but not limited to scanning electron microscopy (SEM) and, without limitation, high-resolution field emission scanning electron microscopes; the SEM instrument is, for example, a Sigma 300 scanning electron microscope from ZEISS, Germany, an Apreo 2 SEM field emission scanning electron microscope, and the like. In some embodiments, a section through the center of the secondary particles is prepared using ion-polished section morphology analysis in combination with scanning electron microscopy (SEM).

[0148] The above method can be used to analyze parameters that include, among others: an a-axis of the primary particles, an angle between the a-axis of the primary particles and the corresponding longitudinal direction (the angle α1), a ratio F1 of the number of primary particles whose a-axis forms the angle α1 with the longitudinal direction, the direction of deviation of the angle α1 from the X-direction, and an anisotropy index I. α1 for the angle α1; a length L of the primary particles along the longitudinal direction, a length W of the primary particles in a direction perpendicular to the longitudinal direction, an R L / W -Average value (R MI ) the inner layer, an R L / W -Average value (R MO ) the outer layer, and the like. The manner in which some of the above parameters are determined is described in Fig.1. The test and analysis procedure can also be applied as described in the following section “Examples”. It should be noted that in Fig. 1 only a part of the section of the primary particles is shown on the section of the oriented secondary particles.

[0149] In some embodiments, the oriented secondary particles are spherical or spheroidal. "Spheroidal particles" have a length-to-diameter ratio close to 1, with non-limiting examples such as 0.8 to 1.2. The length-to-diameter ratio of the spheroidal particles is the ratio of their longest axis to their shortest axis. It can be verified and analyzed using methods and conventional instruments known in the field.

[0150] In some embodiments, F1 ≥ 60%, optionally F1 ≥ 64%, and may also be one of the following percentages, or greater than or equal to one of the following percentages, or selected from the range between one of the following percentages and 100%: 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 80%, 85%, 90%, 95%, etc. Without limitation, F1 may also be in one of the following ranges: 60% to 100%, 70% to 100%, 60% to 90%, 70% to 90%, and the like.

[0151] By regulating the percentage (F1) of primary particles in which an angle α1 is formed between the a-axis and the longitudinal direction within the oriented secondary particles within the aforementioned range, it is advantageous, on the one hand, to more effectively prevent the penetration of the electrolyte solution into the interior of the grain boundaries of the secondary particles. This more effectively prevents the side reaction of the electrolyte solution with the surface of the active cathode material and more effectively improves the actual gram capacity and cycle lifetime of the active cathode material. On the other hand, it is advantageous to create a shorter debedding path for active ions, which is more conducive to improving the actual energy density and the good kinetic performance of the secondary battery.

[0152] In the present application, unless otherwise specified, the percentage of the number of oriented secondary particles in the secondary particles is referred to as P2.

[0153] In some embodiments, P2 ≥ 60%, optionally P2 ≥ 70%, further optionally P2 ≥ 75%, and may also be one of the following percentages, or greater than or equal to one of the following percentages, or selected from the range between any two of the following percentages, or selected from the range between any one of the following percentages and 100%: 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 72%, 75%, 80%, 85%, 90%, 95%, 99%, etc. Without limitation, P2 may also be in any of the following ranges: 60% to 100%, 70% to 100%, 80% to 100%, 90% to 100%, and the like.

[0154] By regulating the percentage (P2) of the number of oriented secondary particles in the secondary particles in the above range, the combined improvement effect of the oriented secondary particles on the high energy density, kinetic power and long cycle life of the secondary battery can be exerted more clearly.

[0155] P2 can be obtained using the following procedure: A randomly selected section containing at least 10 secondary particles is used to determine, based on the results of the SEM analysis of the section through the center of the secondary particle, whether it is an oriented secondary particle or not. If 15° ≤ α1 ≤ 45° and F1 ≥ 60%, an oriented secondary particle is counted; if α1 is not within the above range or F1 < 60%, no oriented secondary particle is counted. The percentage of oriented secondary particles is then calculated based on the counting results.

[0156] In the present application, unless otherwise specified, the value of the length of the primary particles along the longitudinal direction is designated as L, the value of the shortest length perpendicular to the longitudinal direction in the primary particles is designated as W, and the ratio of L to W in the primary particles is designated as R. L / W designated.

[0157] In some embodiments, the oriented secondary particles R L / w the primary particles less than or equal to 4.

[0158] By regulating the angle α1, which is formed by the a-axis of the primary particles with the corresponding longitudinal direction, the length ratio R can be changed. L / W The primary particles are regulated in the longitudinal and transverse directions (the transverse direction being a direction perpendicular to the longitudinal direction). This is achieved by regulating the length ratio R. L / WWithin the above area, the primary particles can be stacked more densely in the radial direction (X-direction) of the oriented secondary particles, thus increasing the energy density of the battery.

[0159] In some embodiments, the L-value, the W-value, and the R can be L / WThe value is obtained as follows: in a section passing through the center of the oriented secondary particles, the direction pointing from the center of the oriented secondary particles to the surface of the oriented secondary particles is considered the X-direction, wherein the X-direction passing through the center of the section of a primary particle is considered the longitudinal direction corresponding to the primary particle, wherein the L-value is determined based on the length value of the primary particle along the corresponding longitudinal direction, wherein the W-value is determined based on the length value of the primary particle along the direction perpendicular to the corresponding longitudinal direction, wherein an R L / W The value is determined based on the ratio obtained by dividing the L-value by the W-value.

[0160] The statistical analysis of the above parameters L, W and R L / Wcan be carried out by means of a section through the center of the oriented secondary particles.

[0161] In some embodiments, the active cathode material has at least one of the following features (each of the numerical parameters of the following features can also be selected from any contextually appropriate value or range):

[0162] In the oriented secondary particles, the RL / W value of the primary particles equals 0. <R L / W ≤4, optional 0.95≤R L / W ≤4.

[0163] In the oriented secondary particles, the average value of R is L / W of the primary particles 1.5 to 2.5, optionally 1.5 to 2.0.

[0164] In some embodiments, the oriented secondary particles of R fulfill L / W The value of the primary particles is 0. <R L / W ≤4, optional 0.95≤R L / W ≤4. The average value of R cannot be considered restrictive. L / WThe primary particle's value can also be one of the following values ​​or lie within a range consisting of any two of the following values: 0.95, 0.96, 0.98, 1, 1.0, 1.1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, 2.0, 2.1, 2.2, 2.4, 2.5, 2.6, 2.8, 3, 3.0, 3.2, 3.4, 3.5, 3.6, 3.7, 3.8, 4.0, 4, and the like. For example, the average value of R can be L / W The primary particles can also be selected from one of the following ranges: 0.95≤R L / W ≤3.8, 0.95≤R L / W ≤3.7, 0.98≤R L / W ≤3.67, and the like.

[0165] In some embodiments, the average value of R in the oriented secondary particles is L / W The primary particle 1.5 to 2.5, optionally 1.5 to 2.0. The average value of R can be used without restriction. L / W the primary particle may also have one of the following values ​​or be in a range consisting of two of the following values: 1.5, 1.6, 1.7, 1.8, 1.85, 1.86, 1.9, 2, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5 and the like.

[0166] By regulating one or two parameters of the value range of R L / W and the average value of R L / W Within the regions described above, it is possible to regulate the orientation and orientation distribution properties of the primary particles within the oriented secondary particles. This allows for a better balance between preventing electrolyte solution penetration and optimizing the reversible disembedding of active ions, resulting in improved equilibrium between high energy density, cycle performance, and good kinetic performance. The results are favorable for combining high energy density, cycle performance, and good kinetic performance.

[0167] In the present application, unless otherwise specified, the length value of the primary particle along the longitudinal direction is designated as L, wherein the distance from the center to the surface of the oriented secondary particles is designated as R; wherein a part from the center of the oriented secondary particles up to a position 2 / 3R from the center is designated as the inner layer, while a part from a position 2 / 3R from the center to the surface of the oriented secondary particles is designated as the outer layer.

[0168] In the present application, unless otherwise stated, the average value of R is given in the oriented secondary particles. L / W the inner layer as R MI denoted, while the average value of R L / W the outer layer as R MO is referred to as such.

[0169] In some embodiments, R MI <R MO .

[0170] In the presence of primary particles with the above angle α1, further control of R leads to MI <R MO to a faster disembedding of the active ions located in the outer layer and outer surface of the secondary particles, which is beneficial to the improvement of the active cathode material and the kinetic performance of the battery.

[0171] In some embodiments, the active cathode material has one or more of the following features (each of the numerical parameters of the following features can also be selected from any contextually appropriate value or range):

[0172] in the oriented secondary particles is R MI <1.8 (optional 1.3≤R MI <1.8) and R MO ≥1.8 (optional 1.8≤R MO ≤2,3);

[0173] In the oriented secondary particles, R fulfills L / W the outer layer 1.2≤R L / W ≤4 and R L / W the inner layer 0.95≤RL / W ≤2.8.

[0174] In some embodiments, the active cathode material has one or more of the following features (each of the numerical parameters of the following features can also be selected from any contextually appropriate value or range):

[0175] In the oriented secondary particles, 1.3 ≤ R MI <1.8, 1.8≤R MO ≤2.3;

[0176] In the oriented secondary particles, R fulfills L / W of at least 80% of the primary particles in the outer layer 1.4≤R L / W ≤4, R L / w of at least 80% of the primary particles in the inner layer 0.95≤R L / W ≤2.0.

[0177] In some embodiments, R MI <1.8, optional 1.3≤R MI <1.8, optionally 1.3≤R MI ≤1.75. The R cannot be considered restrictive. MIFurthermore, it may be one of the following values, or greater than or equal to one of the following values ​​and less than 1.8, or be selected from a range consisting of any two of the following values: 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, and the like. The R value may not be limited to... MI can also be selected from one of the following ranges: 1.4≤R MI <1.8, 1.4≤R MI ≤1.75, 1.4≤R MI ≤1.6, 1.45≤R MI ≤1.55 and the like.

[0178] In some embodiments, R MO <1.8, optional 1.8≤R MO <1.23. The R cannot be considered restrictive. MO furthermore, it may be one of the following values, or greater than or equal to 1.8 and less than or equal to one of the following values, or be selected from a range consisting of any two of the following values: 1.8, 1.85, 1.9, 1.95, 2, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, and the like. The R may not be restrictive. MOcan also be selected from one of the following ranges: 1.8≤R MO ≤2.2, 1.9≤R MO ≤2.1, 2.0≤R MO ≤2.1 and the like.

[0179] In some embodiments, the oriented secondary particles of R fulfill L / W -value of the outer layer 1.2 <R L / W ≤4. Non-restrictive, the RL / W value of the outer layer may be one of the following values ​​or be selected from a range consisting of any two of the following values: 1.2, 1.4, 1.5, 1.6, 1.8, 2.0, 2.5, 3, 3.0, 3.2, 3.4, 3.5, 3.6, 3.7, 3.8, 4, 4.0 and the like.

[0180] In some embodiments, R is fulfilled in the oriented secondary particles. L / W of at least 80% of the primary particles in the outer layer 1.4≤R L / W ≤4. The R cannot be considered restrictive. L / W-value of at least 80% of the number of primary particles in the outer layer must be one of the following values ​​or be in a range consisting of two of the following values: 1.4, 1.5, 1.6, 1.8, 2.0, 2.5, 3, 3.0, 3.2, 3.4, 3.5, 3.6, 3.7, 3.8, 4, 4.0, and the like.

[0181] In some embodiments, the oriented secondary particles of R fulfill L / W -Value of the inner layer 0.95≤R L / W ≤2.8. The R cannot be considered restrictive. L / W -Value of the inner layer shall be one of the following values ​​or be within a range consisting of any two of the following values: 0.95, 0.96, 0.98, 1, 1.0, 1.1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, 2.0, 2.1, 2.2, 2.4, 2.5, 2.6, 2.8 and the like.

[0182] In some embodiments, R is fulfilled in the oriented secondary particles. L / W of at least 80% of the primary particles in the inner layer 0.95≤R L / W ≤2.0. The R cannot be considered restrictive. L / W-value of at least 80% of the number of primary particles in the inner layer must be one of the following values ​​or be selected from a range consisting of two of the following values: 0.95, 0.96, 0.98, 1, 1.0, 1.1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, 2.0 and the like.

[0183] By regulating the combination of the R L / W -value of the inner layer, of the R L / W -Average value of the inner layer (R MI ), of the R L / W -value of the outer layer and the R L / W -Average value of the outer layer (R MO) in the oriented secondary particles in the above manner, it is possible to better control the change in the orientation distribution of the primary particles in the inner and outer layers, in this way the reversible unembedding efficiency of the active ions in the primary particles of the outer layer can be improved, and the prevention of electrolyte solution penetration can also be taken into account, which is more conducive to a better balance of good cycle performance and kinetic performance.

[0184] In some embodiments, the oriented secondary particles of the R L / W -Value of the primary particles from the center of the oriented secondary particles to the surface of the oriented secondary particles successively.

[0185] By R L / WBy controlling the orientation distribution of the primary particles in the oriented secondary particles so that it increases successively from the center to the surface, changes in the orientation distribution of the primary particles in the oriented secondary particles can be better controlled, which contributes to a better improvement in the debedding efficiency of the active ions of the primary particles in the outer layer, and it can also take into account the prevention of electrolyte solution penetration, which contributes to a better balance between good cycle performance and kinetic performance.

[0186] In the present application, unless otherwise stated, the anisotropy index of the angle α1 is referred to as I α1 referred to as the number of primary particles in which the a-axis of the oriented secondary particles forms an angle α1 with the longitudinal direction. α1can be measured as follows: In a section passing through the center of the oriented secondary particles, the angle α1 of the a-axis deviating from the corresponding longitudinal direction clockwise is referred to as a positive angle, while the angle α1 of the a-axis deviating from the corresponding longitudinal direction counterclockwise is referred to as a negative angle, where I α1 The ratio of the number of positive angles to the number of negative angles.

[0187] In some embodiments, 0.4 ≤ I α1 ≤2.5.

[0188] In some of these embodiments, 0.5 ≤ I α1 ≤2.0.

[0189] The I cannot be restricted α1The value may be one of the following values ​​or selected from a range consisting of any two of the following values: 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1, 1.2, 1.4, 1.6, 1.7, 1.75, 1.8, 2.0, 2, 2.2, 2.4, 2.5, and the like. Non-restrictive, I α1 lie in one of the following ranges: 1≤I α1 ≤2.5, 1.5≤I α1 ≤2.0, and the like.

[0190] The above parameter I α1 can be used to reflect the orientation distribution of the primary particles with angle α1 in the oriented secondary particles, and by controlling I α1 Within the above range, it can be achieved that the primary particles have a relatively disordered orientation with angle α1, which is more conducive to preventing the electrolyte solution from penetrating the grain boundaries of the secondary particles and increases the actual gram capacity and cycle lifetime of the active cathode material.

[0191] In some embodiments, the active cathode material has one or more of the following features (each of the numerical parameters of the following features can also be selected from any contextually appropriate value or range):

[0192] The active cathode material exhibits D v 50 from 8 µm to 11 µm, optionally 9 µm to 10 µm;

[0193] The diameter of the primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm, optionally 400 nm to 1500 nm;

[0194] The particle size distribution parameter SPAN of the active cathode material corresponds to the following formula: SPAN=(D v 90-D v 10) / D v 50, where 1.1≤SPAN≤1.4, optionally 1.2≤SPAN≤1.3.

[0195] In some embodiments, the active cathode material D v 50 from 8 µm to 11 µm, optionally 9 µm to 10 µm. Furthermore, D is not limiting. v50 of the active cathode material shall also be one of the following values ​​or be in a range consisting of any two of the following values: 8 µm, 8.5 µm, 9 µm, 9.5 µm, 10 µm, 10.5 µm, 11 µm and the like.

[0196] By regulating D v Within the above range, 50% of the active cathode material can have a more suitable particle size distribution and thus a more suitable specific surface area, which promotes both the prevention of side reactions and a shorter transfer distance for active ions, allowing the secondary battery to have both good cycle performance and good kinetic performance.

[0197] In connection with the present application, a cumulative volume distribution of the particle size D can be vN (where N is any value between 0 and 100) is used to characterize the particle size of the material, wherein the particle size corresponds to a percentage of the cumulative volume distribution of the material that reaches N%, where the percentage of the volume of the particle sizes is less than or equal to D v NN% is. D v N can be determined from the cumulative volume distribution curve of the particle size of the material, where, unless otherwise specified, the cumulative volume distribution curve is cumulative on the side of the small particle size from zero upwards. D v 90, D v 50 and D y Figures 10 are used as examples for illustration. In the present application, unless otherwise stated, D v90 is the particle size corresponding to a cumulative percentage volume distribution fraction of the material of 90%. This parameter means that the particle size of the particles that make up 90% of the volume of the material is less than or equal to D. v 90, and that the particle size of the particles that make up 10% of the volume of the material is larger than D v 90. In the present application, unless otherwise specified, Dv50 is the particle size corresponding to a cumulative percentage volume distribution fraction of the material of 50%. This parameter means that the particle size of the particles constituting 50% of the volume of the material is less than or equal to Dv50, and that the particle size of the particles constituting 50% of the volume of the material is greater than Dv50. In the present application, unless otherwise specified, D y10 the particle size that corresponds to a cumulative percentage volume distribution fraction of the material of 10%.

[0198] D n 10 can be determined from the cumulative molar distribution curve of the particle size of the material, wherein the cumulative molar distribution curve, unless otherwise specified, is cumulative on the side of the small particle size from zero upwards. In the present application, unless otherwise specified, D n 10 the particle size that corresponds to a cumulative percentage of the material's quantity distribution of 10%.

[0199] The meaning of D v 90, D v 50, D y 10 and D nThe value of 10 is understandable to a person skilled in the art and can be determined using instruments and methods known in the trade. For example, it can be determined using a laser particle size analyzer such as the Mastersizer 2000E laser particle size analyzer from Malvern Instruments Ltd. of the United Kingdom and an LS-909 laser particle measuring instrument (Omec) with reference to the GB / T 19077-2016 particle size distribution laser diffraction method. Other instrument models, such as the Malvern 2000 laser particle size analyzer (MasterSizer 2000), can be tested with reference to the standard procedure GB / T19077-2016 / ISO 13320:2009.

[0200] In some embodiments, the diameter of at least some of the primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm, optionally in the range of 200 nm to 1500 nm, and further optionally in the range of 400 nm to 1500 nm. Notwithstanding the above, the diameter of at least some of the primary particles in the oriented secondary particles is in a range consisting of any two of the following values: 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, 1600 nm, and the like.Notwithstanding any restrictions, the diameter of at least some of the primary particles in the oriented secondary particles lies within one of the following ranges: 100 nm to 500 nm, 200 nm to 500 nm, 400 nm to 1600 nm, 400 nm to 1500 nm, 400 nm to 1400 nm, 400 nm to 1350 nm, 400 nm to 1200 nm, 400 nm to 1000 nm, 450 nm to 1600 nm, 450 nm to 1500 nm, 450 nm to 1400 nm, 450 nm to 1350 nm, 450 nm to 1200 nm, 450 nm to 1000 nm, and the like.

[0201] In some embodiments, the diameter of at least 80% of the number of primary particles in the oriented secondary particles lies in the range of 100 nm to 1600 nm, optionally in the range of 200 nm to 1500 nm, and optionally in the range of 400 nm to 1500 nm. Non-restrictively, the diameter of at least 80% of the number of primary particles in the oriented secondary particles lies in a range consisting of any two of the following values: 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, 1600 nm, and likewise.Notwithstanding any restrictions, the diameter of at least 80% of the number of primary particles in the oriented secondary particles lies within one of the following ranges: 100 nm to 500 nm, 200 nm to 500 nm, 400 nm to 1600 nm, 400 nm to 1500 nm, 400 nm to 1400 nm, 400 nm to 1350 nm, 400 nm to 1200 nm, 400 nm to 1000 nm, 450 nm to 1600 nm, 450 nm to 1500 nm, 450 nm to 1400 nm, 450 nm to 1350 nm, 450 nm to 1200 nm, 450 nm to 1000 nm, and the like.

[0202] In some embodiments, the diameter of the primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm, optionally 200 nm to 1500 nm, and further optionally 400 nm to 1500 nm. Non-limitingly, the diameter of the primary particles in the oriented secondary particles may also be one of the following values ​​or a range consisting of any two of the following values: 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, 1600 nm, and the like.The diameter of the primary particles in the oriented secondary particles can also, without restriction, lie in one of the following ranges: 100 nm to 500 nm, 200 nm to 500 nm, 400 nm to 1600 nm, 400 nm to 1500 nm, 400 nm to 1400 nm, 400 nm to 1350 nm, 400 nm to 1200 nm, 400 nm to 1000 nm, 450 nm to 1600 nm, 450 nm to 1500 nm, 450 nm to 1400 nm, 450 nm to 1350 nm, 450 nm to 1200 nm, 450 nm to 1000 nm, and the like.

[0203] Unless otherwise specified, in this application ‘the diameter of the primary particles in the oriented secondary particles’ refers to the largest of the lengths of the primary particles in each direction.

[0204] In the present application, the diameter of the primary particles in the oriented secondary particles can be analyzed by means of a section through the center of the oriented secondary particles, without this constituting a limitation. This section can be obtained using ion-polished section morphology analysis methods, as previously described, and statistically evaluated in conjunction with microscopic morphology observation methods (e.g., SEM). The diameter of the primary particles can be measured from the longest axis in the section of the primary particles in the section representation of the center of the oriented secondary particles.

[0205] By regulating the diameter of the primary particles in the oriented secondary particles within the above range, it is advantageous to regulate the occupancy ratio of the active crystal surface of the primary particles, thus further improving the kinetics of the disembedding of the lithium ions of the primary particles.

[0206] In some embodiments, the L-value of at least 80% of the number of primary particles in the oriented secondary particles lies in the range of 400 nm to 1500 nm, optionally in the range of 400 nm to 1500 nm, and optionally in the range of 400 nm to 1400 nm. Non-restrictively, the L-value of at least 80% of the number of primary particles in the oriented secondary particles lies in a range consisting of any two of the following values: 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, and the like. The L-value of at least 80% of the number of primary particles in the oriented secondary particles is within one of the following ranges (not being restrictive): 400 nm to 1600 nm, 400 nm to 1500 nm, 400 nm to 1400 nm, 400 nm to 1350 nm, 400 nm to 1200 nm, 400 nm to 1000 nm, 450 nm to 1600 nm, 450 nm to 1500 nm, 450 nm to 1400 nm, 450 nm to 1350 nm, 450 nm to 1200 nm, 450 nm to 1000 nm, and the like.

[0207] In some embodiments, the L-value of the primary particles in the oriented secondary particles lies in the range of 400 nm to 1500 nm, optionally in the range of 400 nm to 1500 nm, and optionally in the range of 400 nm to 1400 nm. Non-restrictively, the L-value of the primary particles in the oriented secondary particles lies in a range consisting of any two of the following values: 400 nm, 450 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1300 nm, 1400 nm, 1500 nm, and the like. The L-value of the primary particles in the oriented secondary particles is not restricted and lies within one of the following ranges: 400 nm to 1600 nm, 400 nm to 1500 nm, 400 nm to 1400 nm, 400 nm to 1350 nm, 400 nm to 1200 nm, 400 nm to 1000 nm, 450 nm to 1600 nm, 450 nm to 1500 nm, 450 nm to 1400 nm, 450 nm to 1350 nm, 450 nm to 1200 nm, 450 nm to 1000 nm and the like.

[0208] In some embodiments, the W-value of at least 80% of the number of primary particles in the oriented secondary particles lies in the range of 100 nm to 800 nm, optionally in the range of 200 nm to 700 nm, and optionally in the range of 200 nm to 600 nm. Non-restrictively, the W-value of at least 80% of the number of primary particles in the oriented secondary particles lies in a range consisting of any two of the following values: 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, and the like. The W value of at least 80% of the number of primary particles in the oriented secondary particles is within one of the following ranges: 100 nm to 700 nm, 200 nm to 800 nm, 200 nm to 600 nm, 250 nm to 800 nm, 250 nm to 700 nm, 250 nm to 600 nm and the like.

[0209] In some embodiments, the W-value of the primary particles in the oriented secondary particles lies in the range of 100 nm to 800 nm, optionally in the range of 200 nm to 700 nm, and optionally in the range of 200 nm to 600 nm. Non-restrictive, the W-value of the primary particles in the oriented secondary particles lies in a range consisting of any two of the following values: 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, and the like. The W-value of at least the primary particles in the oriented secondary particles is not restricted and lies within one of the following ranges: 100 nm to 700 nm, 200 nm to 800 nm, 200 nm to 600 nm, 250 nm to 800 nm, 250 nm to 700 nm, 250 nm to 600 nm and the like.

[0210] In some embodiments, the particle size distribution parameter SPAN of the active cathode material satisfies 1.1 ≤ SPAN ≤ 1.4, optionally 1.2 ≤ SPAN ≤ 1.3. Non-restrictive, the particle size distribution parameter SPAN of the active cathode material may also be one of the following values ​​or lie within a range consisting of any two of the following values: 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, and the like.

[0211] By regulating the particle size distribution parameter SPAN of the active cathode material within the above range, it is advantageous that the large and small particles in the active cathode material each have an appropriate volume occupancy ratio, so that the active cathode material exhibits high capacity and simultaneously high powder density, maximizing the volumetric energy density of the cathode side. By matching the particle size to the formed polycrystalline material, the volume energy density of the cathode material can be increased.

[0212] In some embodiments, the active cathode material has one or more of the following features (each of the numerical parameters of the following features can also be selected from any contextually appropriate value or range):

[0213] D v90% of the active cathode material meets 15 µm≤D y 90≤18µm, optional 16µm≤D v 90≤17µm;

[0214] D v 10 of the active cathode material meets 4 µm≤D v 10≤6 µm, optional 4.5 µm≤D v 10≤5.5 µm;

[0215] D n 10 of the active cathode material fulfills D n 10≥2µm.

[0216] In some embodiments, D v 90 of the active cathode material 15 µm≤D v 90≤18 µm, optional 16 µm≤D v 90≤17 µm; Not restrictive, D v 90 of the active cathode material shall also be one of the following values ​​or be in a range consisting of any two of the following values: 15 µm, 15.5 µm, 16 µm, 16.5 µm, 17 µm, 17.5 µm, 18 µm and the like.

[0217] By regulating D v90% of the active cathode material in the above area, it is advantageous to control the large particles in the material so that they have a suitable volume ratio, which favors the control of the specific surface area and the suppression of the side reaction.

[0218] In some embodiments, D y 10 of the active cathode material 4 µm≤D v 10≤6 µm, optional 4.5 µm≤D v 10≤5.5 µm. D cannot be considered limiting. y 10 of the active cathode material shall also be one of the following values ​​or be in a range consisting of any two of the following values: 4 µm, 4.5 µm, 5 µm, 5.5 µm, 6 µm and the like.

[0219] By regulating D y10 of the active cathode material within the above range, it is advantageous to control the small particles in the material so that they have a suitable volume ratio, and it is advantageous to improve the pressing density of the material.

[0220] In some embodiments, D n 10 of the active cathode material D n 10≥2µm.

[0221] By regulating D n 10 of the active cathode material in the above area, the number of small particles in the material can be controlled so that it lies in a more suitable range, which contributes to controlling a more suitable specific surface and thereby improves the storage life of the battery.

[0222] In some embodiments, the active cathode substance in the oriented secondary particles comprises a layered active lithium ion material.

[0223] If the active cathode substance in the oriented secondary particles comprises a layered active lithium ion material, the active cathode substance comprising the oriented secondary particles can be obtained using the methods described by way of example in the present application, but is not limited thereto.

[0224] As a non-restrictive example, the layered active lithium-ion material can include a layered lithium transition metal oxide. A non-restrictive example of the layered active lithium-ion material can also be a lithium-containing nickel composite oxide, and the like.

[0225] In some embodiments, the active cathode substance in the oriented secondary particles comprises a lithium-containing nickel composite oxide.

[0226] In the present application, unless otherwise specified, ‘lithium transition metal oxide’ means an active lithium ion material containing a transition metal element.

[0227] Unless otherwise specified, the term "lithium-containing nickel composite oxide" in this application refers to an active lithium-ion material containing a nickel element. It is understood that the lithium-containing nickel composite oxide contains at least one lithium element, one nickel element, and one oxygen element, and may or may not contain other types of transition metal elements such as Zr, Al, Sr, and the like. The lithium-containing nickel composite oxide may or may not contain non-metallic elements such as B, C, and the like.

[0228] The introduction of lithium-containing nickel composite oxides into the active cathode substance of the oriented secondary particles makes the introduction of nickel elements advantageous for increasing the energy density of the active cathode material, in addition to improving the performance of the battery.

[0229] In the present application, the molar ratio of elemental nickel to elemental oxygen (O) in the lithium-containing nickel composite oxide is defined as Q. Ni / O designated as such unless otherwise stated.

[0230] In some embodiments, 0.3≤Q is present in the oriented secondary particles. Ni / O ≤0.5, optionally 0.4≤Q Ni / O ≤0.5. In the oriented secondary particles, Q can Ni / O one of the following values ​​or within a range consisting of any two of the following values: 0.3, 0.35, 0.4, 0.45, 0.5 and the like.

[0231] In the present application, the molar ratio of nickel element to lithium element (Li) in the lithium-containing nickel composite oxide is defined as Q. Ni / Li designated as such unless otherwise stated.

[0232] In some embodiments, 0.6≤Q is present in the oriented secondary particles. Ni / Li ≤1, optional 0.8≤Q Ni / Li ≤1, In the oriented secondary particles, Q can Ni / Li one of the following values ​​or within a range consisting of any two of the following values: 0.6, 0.65, 0.66, 2 / 3, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1 and the like.

[0233] By controlling the molar ratio of the nickel element and the oxygen element (Q Ni / O ) in the lithium-containing nickel composite oxide and / or the molar ratio of the nickel element and the lithium element (Q Ni / Li) in the lithium-containing nickel composite oxide in the above areas, the active cathode substance can be produced in such a way that it has a high nickel content, which is more conducive to improving the energy density of the active cathode material.

[0234] In some embodiments, the lithium-containing nickel composite oxide comprises at least one cobalt element (Co) and one M element, wherein the M element is at least one Mn element or one Al element. In some embodiments, the lithium-containing nickel composite oxide comprises the Co element and the Mn element. In some embodiments, the lithium-containing nickel composite oxide comprises one Co element and one Al element.

[0235] In some embodiments, the lithium-containing nickel composite oxide is a lithium-containing nickel-cobalt-manganese composite oxide.

[0236] Unless otherwise specified, in this application, “lithium-containing nickel-cobalt-manganese composite oxide” refers to an active lithium-ion material containing nickel, cobalt, and manganese. It is understood that the lithium-containing nickel-cobalt-manganese composite oxide contains at least one lithium element, one nickel element, one cobalt element, one manganese element, and one oxygen element, and may or may not contain other types of transition metal elements such as Zr, Al, Sr, and the like. The lithium-containing nickel composite oxide may or may not contain non-metallic elements such as B, C, and the like.

[0237] In some embodiments, the lithium-containing nickel composite oxide comprises a doping element, wherein Q Ni / O<0.5, wherein the doping element comprises at least one of the elements Zr, Al, B, Sr, and Ca. In some embodiments, the doping element is selected from one or more of the elements Zr, Al, B, Sr, and C. In some embodiments, the doping element is a combination of Zr, Al, B, Sr, and C. Q Ni / O can, but is not limited to 0.3≤Q Ni / O ≤0.5, optionally 0.4≤Q Ni / O ≤0.5.

[0238] In some embodiments, at least part of the primary particles comprises a particle body and a coating layer arranged on at least part of the surface of the particle body, wherein the particle body comprises a lithium-containing nickel composite oxide, and wherein the coating layer comprises at least one of the elements Zr, Al, B, Sr and Ca.

[0239] In some embodiments, the primary particles comprise a particle body and a coating layer arranged on at least a part of the surface of the particle body, wherein the particle body comprises a lithium-containing nickel composite oxide, and wherein the coating layer comprises at least one or more of the elements Zr, Al, B, Sr and Ca.

[0240] In some embodiments, the oriented secondary particles have one or more of the following features (each of the numerical parameters of the following features can also be selected from any value or range that is appropriate in the context):

[0241] In the oriented secondary particles, 0.3 ≤ Q Ni / O ≤0.5, optionally 0.4≤Q Ni / O ≤0.5;

[0242] In the oriented secondary particles, 0.6 ≤ Q Ni / Li ≤1, optional 0.8≤Q Ni / Li ≤1;

[0243] The lithium-containing nickel composite oxide comprises at least one of a cobalt element and one M element, wherein the M element is at least one of a Mn element and one Al element;

[0244] The lithium-containing nickel composite oxide comprises a dopant element, where Q Ni / O <0.5, wherein the doping element comprises at least one of the elements Zr, Al, B, Sr and Ca;

[0245] At least one part of the primary particles comprises a particle body and a coating layer arranged on at least part of the surface of the particle body, wherein the particle body comprises a lithium-containing nickel composite oxide, and wherein the coating layer comprises at least one of the elements Zr, Al, B, Sr and Ca.

[0246] By controlling Q Ni / O and / or Q Ni / LiIn the area above, the lithium-containing nickel composite oxide has a high nickel content, which can significantly improve the energy density of the active cathode material.

[0247] The introduction of the cobalt element (Co) into the lithium-containing nickel composite oxide stabilizes the material structure and improves the cycle and multiplication performance of the active cathode material.

[0248] The introduction of manganese (Mn) into lithium-containing nickel composite oxide contributes to cost reduction and improvement of the structural stability of the materials.

[0249] The introduction of aluminum element (Al) into the lithium-containing nickel composite oxide contributes to improving the cycle stability of the materials.

[0250] Modifying lithium-containing nickel composite oxide with one or more of the above dopants and coatings can improve the material's stability, increase its energy density, and extend its cycle life. For example, the structure of lithium-containing nickel composite oxide can be stabilized by bulk-phase doping. The surface of the lithium-containing nickel composite oxide can be coated with a fast-ion conductor, for instance, thereby improving the material's energy density and cycle life.

[0251] In some embodiments, 0.3 ≤ Q Ni / O ≤0.5, optionally 0.4≤Q Ni / O≤0.5, a suitable range can also be considered in the context. In the oriented secondary particles, the active cathode substance comprises one or more of a lithium nickel cobalt manganese oxide, a lithium nickel cobalt aluminum oxide, and a modified form thereof, wherein the modified form comprises one or more of a doping modification and a coating modification, wherein the dopant used for the doping modification comprises at least one of the elements Zr, Al, B, Sr, and Ca, while the coating element used for the coating modification comprises at least one of the elements Zr, Al, B, Sr, and Ca;

[0252] The molar ratio R Ni / O of the nickel element and the oxygen element in the active cathode substance fulfills 0.4≤R Ni / O ≤0.5.

[0253] In some embodiments, the active cathode material has one or more of the following features:

[0254] The active cathode material exhibits D v 50 from 8 µm to 11 µm, optionally 9 µm to 10 µm;

[0255] The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm, optionally 400 nm to 1500 nm;

[0256] The particle size distribution parameter SPAN of the active cathode material corresponds to the following formula: SPAN=(D v 90-D v 10) / D v 50, where 1.1≤SPAN≤1.4, optionally 1.2≤SPAN≤1.3.

[0257] A ternary active cathode compound with a high nickel content and a modified version thereof can be incorporated into the active cathode compound of the oriented secondary particles. The modification can include one or more doping and coating modifications, which can be used to obtain a ternary active cathode compound with high energy density and long lifetime. The structure of the ternary active cathode compound can be stabilized by bulk-phase doping, and the energy density and cycle lifetime of the material can be improved by applying a fast-ion conductor coating to the surface of the ternary active cathode compound.In combination with the regulation of the angle α1 and F1, the orientation and distribution of the primary particles in the secondary particles of the active cathode material can be regulated. This allows for a balance between preventing the penetration of the electrolyte solution into the interior and optimizing the distance of the lithium ion transfer path, thereby improving the mass energy density and the diffusion kinetics of the lithium ions in the material. This can be achieved by controlling one or more of the parameters D. vBy adjusting the size distribution of the active cathode material, the diameter of the primary particles in the oriented secondary particles, and the particle size distribution parameter SPAN of the active cathode material within the ranges mentioned above, a further combination of the above advantages can be achieved. For example, by regulating the particle size distribution parameter SPAN of the active cathode material within the range mentioned above, it is advantageous to have a suitable volume fraction of large or small particles in the active cathode material, which can further improve the powder compaction density of the material and the volumetric energy density of the cathode foil. By matching the size of the secondary particles to the primary particles, the resulting polycrystalline material can increase the volumetric energy density of the cathode material.Furthermore, a longer cycle life can be achieved by combining doping and coating modification methods in order to improve the bulk phase structure of the material as well as the stability of the surface.

[0258] In some embodiments, the L-average value of the inner layer in the oriented secondary particles is less than 700 nm (optionally, the L-average value of the inner layer is less than 660 nm) and the L-average value of the outer layer is greater than or equal to 720 nm (optionally, the L-average value of the outer layer is greater than or equal to 750 nm).

[0259] Non-restrictive, the L-average value of the inner layer in the oriented secondary particles can be one of the following values, or less than or equal to one of the following values, or less than one of the following values: 690 nm, 680 nm, 670 nm, 660 nm, 650 nm, and the like.

[0260] Non-restrictive, the L-average value of the outer layer in the oriented secondary particles can be one of the following values, or greater than or equal to one of the following values, or greater than one of the following values: 720nm, 730nm, 740nm, 750nm, 760nm, 770nm, 780nm and the like.

[0261] In some embodiments, the inner layer of the oriented secondary particles has an average value of L less than 660 nm and the outer layer has an average value of L greater than or equal to 750 nm.

[0262] For the active cathode material, in which the active cathode substance in the oriented secondary particles comprises a lithium-containing nickel composite oxide, it is possible, by controlling the average values ​​of L in the inner and outer layers of the oriented secondary particles in the regions mentioned above, to both equip the outer layer with a faster debedding efficiency of the active ions and to equip the inner layer with a larger angle to better prevent the penetration of the electrolyte solution into the grain boundaries. In this way, the actual energy density, cycle performance, and kinetic performance of the battery can be comprehensively improved.

[0263] In the present application, unless otherwise stated, the ‘secondary battery’ comprises a battery cell.

[0264] Unless otherwise specified, the term "battery cell" in this application refers to a basic unit capable of converting chemical energy and electrical energy into one another. Typically, the battery cell comprises a cathode foil, an anode foil, an electrolyte, and a separator. During charging and discharging, active ions are embedded and unembedded between the cathode foil and the anode foil. The electrolyte acts as an ion conductor between the cathode foil and the anode foil. The separator is located between the cathode foil and the anode foil and serves primarily to prevent a short circuit between the cathode and the anode while allowing the passage of ions.

[0265] In some embodiments, the secondary battery further comprises an anode foil, a separator and an electrolyte solution, wherein the separator is arranged between the cathode foil and the anode foil.

[0266] In some embodiments, the secondary battery is a lithium-ion secondary battery.

[0267] In some embodiments, the secondary battery is a lithium-ion secondary battery, and the electrolyte salt may contain a lithium electrolyte salt.

[0268] The following are some additional descriptions of the cathode foil.

[0269] The cathode foil comprises a cathode collector and an active cathode material layer, which is provided on at least one surface of the cathode collector. The active cathode material layer comprises an active cathode material. It is self-evident that the active cathode material comprises the oriented secondary particles described above.

[0270] The active cathode material comprises an active cathode substance.

[0271] The active cathode material comprises secondary particles, wherein the secondary particles are agglomerated particles comprising a multitude of primary particles; wherein the primary particles comprise an active cathode substance.

[0272] The active cathode substance in the active cathode material may refer to the above description, but is not limited to it.

[0273] Without restriction, the weight percentage of the active cathode material in the active cathode material layer may be greater than or equal to 80 wt.%, and may furthermore be greater than or equal to 90 wt.%.

[0274] In some embodiments, the active cathode material layer may be a layered active lithium ion material known in the art for use in batteries.

[0275] In some embodiments, the active cathode material layer may be a lithium-containing nickel composite oxide, which is known in the art for use in batteries.

[0276] As a non-restrictive example, the layered active lithium ion material may contain one or more of the following materials: lithium-containing nickel composite oxide and modified compounds thereof. However, the present application is not limited to these materials. It is possible that only one of these active cathode materials is used or that more than two are used in combination. Examples of the lithium-containing nickel composite oxide may include, but are not limited to, one or more of the following oxides: lithium cobalt oxide, lithium-containing nickel composite oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and modified compounds thereof, and the like.Non-restrictive examples of lithium cobalt oxide may include LiCoO2; non-restrictive examples of lithium nickel composite oxide may include LiNiO2; and non-restrictive examples of lithium manganese oxide may include LiMnO2, LiMn2O4 and the like; non-restrictive examples of lithium nickel cobalt manganese oxide may include LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 (designated), LiNi 0,5 Co 0,2 Mn 0,3 O2 (also known as NCM) 523 (designated), LiNi 0,5 Co 0,25 Mn 0,25 O2 (also known as NCM) 211 (designated), LiNi 0,6 Co 0,2 Mn 0,2 O2 (also known as NCM) 622 (designated), LiNi 0,8 Co 0,1 Mn 0,1 O2 (also known as NCM) 811 designated) and the like; non-restrictive examples of lithium nickel cobalt aluminum oxides include LiNi 0,80 Co 0,15 Al 0,05 O2 included.

[0277] It is understood that during the charging and discharging process, the battery is accompanied by the de-embedding and depletion of lithium (Li), and the Li content in the cathode foil of the battery differs during discharge in different states.

[0278] In the exemplary description of the active cathode compound in this application, the Li content may be in the initial state of the material or in a non-initial state after charge / discharge cycles, unless otherwise specified. When the active cathode compound is applied to a cathode foil in a battery system, the Li content in the active cathode compound in the cathode foil typically changes after a charge / discharge cycle. The Li content can be measured, among other methods, by its molar atomic content, but this is not the only possible method. In the example of wet manufacturing of the cathode foil, "the Li content is the initial state of the material" means that the initial state of the material refers to its condition before being added to the cathode slurry.It is understood that a new material or substance obtained by a suitable modification based on the active cathode substance listed herein shall also fall within the scope of application of the active cathode substance, and the aforementioned suitable modification refers to an acceptable modification method for the active cathode substance and is not restrictive, such as a coating modification.

[0279] In the exemplary description of the active cathode substance in the present application, the oxygen (O) content is only a theoretical state value, and the lattice release of oxygen leads to a change in the molar atomic content of oxygen, and the actual O content will fluctuate. The O content can be measured, inter alia, based on the molar atomic content, but is not limited to this method.

[0280] In some embodiments, the cathode collector can be a metal foil or a composite collector. For example, an aluminum foil can be used as the metal foil. In the cathode collector, the composite collector can comprise a base layer of polymeric material and a metal layer formed on at least one surface of the polymeric base layer. The composite collector can be produced by depositing the metallic material onto the polymeric base material. As a non-limiting example of the metallic material, the cathode collector can comprise at least one of aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, and the like.As a non-restrictive example of the polymer base layer, the cathode collector can include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) and other substrates.

[0281] In some embodiments, the active cathode material layer optionally comprises a binder. As a non-limiting example, the binder may comprise one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin. Typically, the weight percent of the binder in the active cathode material layer may be 0 to 10 wt%, optionally 0 to 8 wt%, and further optionally 1 wt% to 5 wt%.

[0282] In some embodiments, the active cathode material layer optionally comprises a conductive agent. As a non-limiting example, the conductive agent may comprise one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dot, carbon nanotubes, graphene, and carbon nanofibers. Typically, the weight percent of the conductive agent in the active cathode material layer may be 0 to 10 wt.%, optionally 0 to 8 wt.%, and further optionally 0 to 5 wt.%.

[0283] In some embodiments, the cathode foil can be produced as follows: Dispersing the components described above for the production of the cathode foil, such as the active cathode material, the conductive agent, the binder, and any other components, in a solvent to form a cathode slurry. Furthermore, applying the cathode slurry to at least one side of the cathode collector and obtaining the cathode foil after drying, cold pressing, and other processes. Cold pressing can be carried out using a cold rolling mill. The type of solvent in the cathode slurry can include, but is not limited to, any of the embodiments described above and can, for example, include N-methylpyrrolidone (NMP).The surface of the cathode collector coated with the cathode slurry can be located on a single surface or on both surfaces. The solids content of the cathode slurry can range from 40 to 80 wt%. The viscosity of the cathode slurry at room temperature can be adjusted from 5000 mPa·s to 25000 mPa·s. The surface density of the coating unit, based on the dry weight (excluding solvent), can be 13 mg / cm². 2 up to 20 mg / cm² 2 This is based on the coating quantity on one side of the cathode collector. The density of the cathode foil can be 3.0 g / cm³. 3 up to 3.6 g / cm³ 3 to be, optionally 3.3 g / cm² 3 up to 3.5 g / cm³ 3 .

[0284] The term "density" used in the present application has a meaning known in the art and is one of the reference indices for the energy density of the material. In the present application, unless otherwise specified, the density of the electrode foil refers to the ratio of the mass of the active electrode material layer to its volume. The density of the cathode foil refers to the ratio of the mass of the active cathode material layer to its volume, and the density of the anode foil refers to the ratio of the mass of the active anode material layer to its volume.

[0285] The following are some descriptions of the anode foil.

[0286] The anode foil comprises an anode collector and an active anode material layer provided on at least one surface of the anode collector, wherein the active anode material layer contains an active anode substance.

[0287] Without restriction, the weight percentage of the active anode substance in the active anode material layer may be greater than or equal to 80 wt.%, and may furthermore be greater than or equal to 90 wt.%.

[0288] As a non-restrictive example, the anode collector has two surfaces facing away from each other in its thickness direction, and the active anode material layer is provided on one or both of the two facing surfaces.

[0289] In some embodiments, the anode collector can be a metal foil or a composite collector. For example, a copper foil can be used as the metal foil. In the anode collector, the composite collector can comprise a base layer of polymeric material and a metal layer formed on at least one surface of the polymeric base layer. The composite collector can also be formed by depositing the metallic material onto the polymeric base material. As a non-limiting example of the metallic material, the anode collector can comprise one or more of copper, a copper alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, and the like.As a non-restrictive example of the polymer base layer, the anode collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) and other substrates.

[0290] In some embodiments, the active anode material may be an active anode material known in the art for use in batteries. As a non-limiting example, the active anode material may, for instance, comprise at least one or more of the following materials: synthetic graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate. The silicon-based material may comprise one or more of monolithic silicon, silicon oxides, silicon-carbon complexes, silicon-nitrogen complexes, and silicon alloys. The tin-based material may comprise one or more of monolithic tin, tin oxide compounds, and tin alloys.However, the present application is not limited to these materials or substances, and other conventional substances that can be used as the active anode substance in batteries may also be used. It is possible to use only one of these active anode substances or to use more than two in combination.

[0291] In some embodiments, the active anode material comprises one or more of the following: a carbon-based material, a silicon-based material, a tin-based material, and lithium titanate, as well as a modified form of one of the above materials, wherein the modified form comprises one or more of the following: a doped modified form and a coated modified form. Both the doped modified form and the coated modified form may be adopted from or based on existing modified forms, including, but not limited to, the choice of element type and doping quantity. The carbon-based material may comprise one or more of the following: graphite material, soft carbon, hard carbon, and the like. The graphite material may contain one or more synthetically produced graphite and natural graphite.

[0292] In some embodiments, the active anode material comprises a carbon-based material and a silicon-based material. The total mass fraction of the carbon-based and silicon-based materials in relation to the total mass of the active anode material can be ≥80%, optionally ≥90%, further optionally ≥95%, further optionally ≥96%, etc., further optionally 100%, etc. The percentage of the sum of the masses of the graphite material and the silicon-based material in relation to the total mass of the active anode substance may furthermore be one of the following percentages, or greater than or equal to one of the following percentages and less than or equal to 100%, or in a range consisting of any two of the following percentages: 80%, 82%, 83%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 98% and the like.The carbon-based material can be defined as previously described; for example, the carbon-based material can be a graphite material. The carbon-based material content can also be specified in connection with any suitable embodiment.

[0293] In some embodiments, the active anode material comprises a carbon-based material. Without limitation, the percentage by mass of the carbon-based material in the active anode material may be ≥80%, optionally ≥90%, further optionally ≥95%, further optionally ≥96%, etc., further optionally 100%, etc. The percentage by mass of the carbon-based material in the active anode material may also be any one of the following percentages, or greater than or equal to any one of the following percentages and less than or equal to 100%, or in a range consisting of any two of the following percentages: 80%, 82%, 83%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 96%, 98%, and the like. The carbon-based material can be defined as described above; for example, the carbon-based material can be a graphite material.

[0294] In some embodiments, the active anode material layer optionally comprises a binder. The binder may be, without limitation, one or more of the following: 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). The weight percentage of the binder in the active anode material layer may, without limitation, be 0 wt% to 20 wt%, 0 wt% to 10 wt%, 0 wt% to 5 wt%, 1 wt% to 5 wt%, or optionally 1 wt% to 3 wt%.

[0295] In some embodiments, the active anode material layer optionally comprises a conductive agent. This conductive agent may comprise, without limitation, one or more of the following: superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dot, carbon nanotubes, graphene, and carbon nanofibers. The weight percentage of the conductive agent in the active anode material layer may, without limitation, be 0 to 15 wt.%, further optionally 0 to 10 wt.%, and still optionally 0 to 5 wt.%.

[0296] In some embodiments, the active anode material layer optionally includes further additives, such as thickening agents (e.g., sodium carboxymethylcellulose (CMC-Na)), etc. The weight percentage of other additives in the active anode material layer can be, without limitation, 0 wt.% to 15 wt.%, further optionally 0 wt.% to 10 wt.%, further optionally 0 wt.% to 5 wt.%, and still further optionally 0 wt.% to 3 wt.%.

[0297] In some embodiments, the anode foil can be produced as follows: Dispersing the components described above for the production of the anode foil, such as the active anode substance, the conductive agent, the binder, and any other components, in a solvent (a non-restrictive description of the solvent is, for example, deionized water) to form the anode slurry. Furthermore, applying the anode slurry to at least one side of the anode collector and obtaining the anode foil after drying, cold pressing, and other processes. Cold pressing can be carried out using a cold rolling mill. The surface of the anode collector coated with the anode slurry can be on a single surface of the anode collector or on both surfaces of the anode collector. The solids content of the anode slurry can be 30 wt.% to 70 wt.%, optionally 40 wt.% to 60 wt.%.The viscosity of the anode slurry at room temperature can be adjusted from 2000 mPa·s to 10000 mPa·s, optionally from 3000 mPa·s to 10000 mPa·s. The surface density of the coating unit, based on the dry weight (less solvent), when coating the anode slurry can be 6.5 mg / cm². 2 up to 13 mg / cm² 2 This is based on the coating quantity on one side of the anode collector. The density of the anode foil can be 1.0 g / cm³. 3 up to 2.0 g / cm³ 3 to be, optionally 1.0 g / cm² 3 up to 1.8 g / cm³ 3 .

[0298] The electrolyte is described below using an example.

[0299] The electrolyte acts as an ion conductor between the cathode foil and the anode foil. Unless otherwise specified, the electrolyte is a liquid electrolyte.

[0300] In some embodiments, an electrolyte solution is used for the electrolyte. This electrolyte solution consists of an electrolyte salt and a solvent.

[0301] In some embodiments, the electrolyte is a non-aqueous electrolyte. The non-aqueous electrolyte may contain an electrolyte salt and a solvent.

[0302] The concentration of the electrolyte salt in the electrolyte solution can typically be 0.5 mol / L to 5 mol / L, such as, but not limited to, 0.5 mol / L, 1 mol / L, 1.5 mol / L and the like.

[0303] In some embodiments, the electrolyte salt comprises an electrolyte lithium salt. Without limitation, the electrolyte lithium salt may comprise one or more of the following: lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium bis(fluorosulfonyl)amide (LiFSI), lithium bis(trifluoromethanesulfonyl)amide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorophosphate (LiPO2F2), lithium difluorooxalic acid borate (LiDFOB), lithium diboronic acid borate (LiBOB), lithium difluorodioxyphosphate (LiDFOP), and lithium tetrafluorooxalic acid phosphoric acid (LiTFOP).

[0304] In some embodiments, the secondary battery is a lithium-ion secondary battery, and the electrolyte salt may contain a lithium electrolyte salt.

[0305] In some embodiments, the solvent in the non-aqueous electrolyte may contain one or more of the following: ethylene carbonate (EC), propylene carbonate (PC), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methylenepropylene carbonate (MPC), ethylenepropylene carbonate (EPC), butylenyl carbonate (BC), fluorinated ethylene carbonate (FEC), methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclobutane sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0306] In some embodiments, the electrolyte solution optionally includes an additive. The additive may, for example, include a film-forming additive for the negative electrode and a film-forming additive for the positive electrode, and may also include an additive that can improve certain battery properties, such as an additive to improve the battery's overcharge performance, an additive to improve the battery's high- or low-temperature performance, etc.

[0307] In some embodiments, the additive in the electrolyte solution may contain, but is not limited to, one or more of fluoroethylene carbonate (FEC), vinyl difluorocarbonate (DFEC), trifluoromethyl vinyl carbonate (TFPC).

[0308] In some embodiments, the electrolyte solution comprises a solvent, wherein the solvent contains at least one cyclic carbonate and at least two chain carbonates.

[0309] In some embodiments, the solvent in the electrolyte solution comprises a cyclic C 3-6 -Carbonate, a first C 4-10 -chain carbon and a second C 3-8 -Chain carbonate in a volume ratio of 1:(0.9 to 1.1):(0.9 to 1.1), wherein the first chain carbonate has a larger number of carbon atoms than the second chain carbonate.

[0310] In some embodiments, the cyclic C comprises 3-6 -Carbonate in the electrolyte solution vinyl carbonate, the C 4-10 -First-chain carbonate diethyl carbonate and the C 3-8 -Second-chain carbonate dimethyl carbonate.

[0311] The separator is described below using an example.

[0312] In some embodiments, the secondary battery further comprises a separator. The present application does not impose any specific restrictions regarding the type of separator, and any known separator with a porous structure and good chemical and mechanical stability may be selected.

[0313] In some embodiments, the separating film material can comprise at least one or more glass fibers, nonwovens, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film without any particular restriction. If the separating film is a multi-layer composite film, the materials of the layers can be the same or different without any particular restriction.

[0314] In some embodiments, the thickness of the separator is 6 µm-40 µm, optionally 12 µm-20 µm.

[0315] In some embodiments, the cathode foil, the anode foil and the insulating film can be assembled into an electrode assembly by a winding process or a stacking process.

[0316] In some embodiments, the secondary battery may include an outer casing. The outer casing can be used to encapsulate the electrode component and electrolyte described above.

[0317] In some embodiments, the outer packaging of the secondary battery may be a hard casing, e.g., a hard plastic casing, an aluminum casing, a steel casing, etc. The outer packaging of the secondary battery may also be a soft casing, e.g., a bag-like soft casing. The material of the soft casing may be plastic, and further, non-limiting examples of plastics may include one or more of the following materials: polypropylene, polybutylene terephthalate, and the like.

[0318] The secondary battery comprises at least one battery cell. The secondary battery can comprise one or more battery cells.

[0319] The present application does not impose any special restrictions regarding the shape of the battery cell, which can be cylindrical, square, or any other shape. For example, in Fig.Figure 3 shows a battery cell 5 with a rectangular structure as an example.

[0320] In some embodiments, such as in Fig.As shown in Figure 4, the outer packaging can comprise a housing 51 and a cover plate 53. The housing 51 can include a base plate and side plates connected to the base plate, the base plate and the side plates forming a receiving cavity. The housing 51 has an opening that communicates with the receiving cavity, and the cover plate 53 can serve to cover the opening to close the receiving cavity. The cathode foil, the anode foil, and the separator film can be assembled into an electrode assembly 52 by a winding or stacking process. The electrode assembly 52 is encapsulated in the receiving cavity. The electrolyte solution is exchanged into the electrode assembly 52. ​​The number of electrode assemblies 52 contained in the battery cell 5 can be one or more, and the person skilled in the art can make the selection as required.

[0321] In some embodiments, the electrolyte solution has a filling factor of more than or equal to 1.6 g / Ah.

[0322] The secondary battery can be a battery module 4 or a battery pack 1.

[0323] The battery module comprises at least one battery cell. The number of battery cells contained in the battery module can be one or more, and the person skilled in the art can select a suitable number depending on the application and capacity of the battery module.

[0324] Fig. Figure 5 shows a battery module 4 as an example. As in Fig. As shown in Figure 5, the multiple battery cells 5 in the battery module 4 can be arranged sequentially along a longitudinal direction of the battery module 4. Of course, they can also be arranged in any other desired manner. Furthermore, the multiple battery cells 5 can be secured by fastening elements.

[0325] Optionally, the battery module 4 can also include a casing with a receiving space in which the multitude of battery cells 5 are housed.

[0326] In some embodiments, the above battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more, and the person skilled in the art can select a suitable number depending on the application and capacity of the battery pack.

[0327] The Fig. 6 and Fig. Figure 7 shows a battery pack 1 as an example. As in Fig. 6 and Fig.As shown in Figure 7, the battery pack 1 can comprise a battery housing and a plurality of battery modules 4 arranged within the battery housing. The battery housing comprises an upper housing 2 and a lower housing 3, the upper housing 2 serving to cover the lower housing 3 and form an enclosed space for receiving the battery modules 4. The plurality of battery modules 4 can be arranged within the battery housing in any desired configuration.

[0328] A second aspect of the present application provides an active cathode material comprising the above-mentioned oriented secondary particles.

[0329] In some embodiments, the active cathode material comprises secondary particles, wherein the secondary particles are agglomerated particles comprising primary particles; wherein the primary particles comprise an active cathode substance;

[0330] In each of the secondary particles, the direction pointing from a center of the secondary particle to its surface is called the X-direction; the X-direction passing through the center of one of the primary particles is called the longitudinal direction; and in each of the primary particles, the longest axis of the primary particle is called the a-axis.

[0331] The secondary particles comprise oriented secondary particles; wherein in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1≥60%.

[0332] The cathode foils produced with the above-mentioned active cathode material can be used to manufacture secondary batteries with high energy density, good kinetic performance, and long cycle life. Controlling the orientation angle and the proportion of primary particles within the oriented secondary particles in the active cathode material can prevent the electrolyte solution from penetrating the interior of the secondary particle grain boundaries, thus suppressing the side reaction between the electrolyte solution and the surface of the active cathode material.The actual gram capacity and cycle life of the active cathode material can be improved in this way, and a shorter debedding path for active ions can also be achieved, which helps promote the rapid debedding of active ions during charging and discharging, which can improve the actual energy density of the secondary battery and enable good kinetic performance from the secondary battery.

[0333] In some embodiments, the active cathode material is provided in the secondary battery described in the first aspect of the present application.

[0334] Another aspect of the present application provides a manufacturing process for an active cathode material that can be used to manufacture the above active cathode material.

[0335] In some embodiments, a manufacturing process for an active cathode material is provided, comprising the following steps: S10: Production of the precursor; and S20: First sintering of the first mixture containing the precursor and a lithium source at a temperature T1 to obtain a first sintered product, and then second sintering of the second mixture containing the first sintered product at a temperature T2 to obtain the active cathode material; where T1>T2.

[0336] In step S10, the type of transition metal element in the precursor can be selected according to the desired crystal structure of the active cathode material, and thus a suitable metal source can be selected.

[0337] Step S10 can be carried out by a co-precipitation process to produce the precursor, but is not limited to this.

[0338] In the embodiment above, the temperature T1 is higher than the temperature T2, and therefore the temperature condition for the first sintering can be referred to as the "high temperature condition" and the temperature condition for the second sintering as the "low temperature condition".

[0339] In some embodiments, the temperature T1 at which the first sintering is carried out can be between 700°C and 800°C, such as 700°C, 720°C, 740°C, 750°C, 760°C, 780°C, 800°C, etc., and can be selected from a range consisting of any two of the aforementioned temperatures. Furthermore, the sintering time for carrying out the first sintering can be between 15 and 30 hours, such as 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, and the like, and can also be selected from a range consisting of any two of the aforementioned times.

[0340] In some embodiments, the temperature T2 at which the second sintering is carried out can be from 200°C to 500°C, such as 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, and the like, and can also be selected from a range consisting of any two of the aforementioned temperatures. Furthermore, the sintering time for carrying out the second sintering can be from 3 hours to 8 hours, such as 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, and the like, and can also be selected from a range consisting of any two of the aforementioned times.

[0341] After step S10, a laser particle measuring device can be used to perform a test to obtain the particle size and SPAN value of the precursor particles, so that the precursors with a suitable particle size range and SPAN value can be sieved for step S20.

[0342] Unless otherwise specified, at least one of the two processes, the first sintering process and the second sintering process, is carried out in an oxygen-containing atmosphere. In some embodiments, both the first and second sintering processes are carried out under an oxygen atmosphere.

[0343] In step S20, the molar ratio of precursor to lithium source, based on OH, can be 1:(1.03 to 1.07), e.g., 1:1.03, 1:1.04, 1:1.05, 1:1.06, 1:1.07, and the like, without restriction. Considering the lithium loss during the sintering process, the lithium is usually produced in a slight excess.

[0344] In step S20, when the first sintering is carried out, the initial mixture may also contain a dopant to introduce the dopant element. It is understood that at typical doping amounts, the introduction of dopants usually has no effect on the type of crystal structure of the grains.

[0345] In step S20, during the second sintering process, the second mixture may further contain a coating agent for introducing the coating element. It is understood that the introduction of the coating element can form a coating layer on at least a portion of the surface of the grains obtained from the first sintered product.

[0346] Starting from the precursor, the doping modification and the coating modification can be carried out simultaneously without any limitations.

[0347] Using the example of an active cathode material comprising a lithium-containing nickel composite oxide, a manufacturing process for an active cathode material is provided in some embodiments, comprising steps S10 and S20, where step S10 is S100 and step S20 is S200.

[0348] S100: Production of a nickel-containing precursor.

[0349] The nickel-containing precursor can be prepared by a process comprising the following steps: A metal source, including a nickel source, is dissolved in water according to the elemental composition in the target chemical formula of the active cathode material, in the desired type and dosage, to prepare a metal solution. The metal solution, the complexing agent, and the precipitating agent are mixed, and a co-precipitation reaction is carried out under dispersive conditions. Solid-liquid separation, washing, and drying are then performed to obtain the nickel-containing precursor. The nickel-containing precursor is the corresponding metal hydroxide.

[0350] In step S100, the grain structure and particle morphology in the active cathode material can be controlled by adjusting the type of metal source, i.e., by controlling the type of transition metal element in the nickel-containing precursor. For example, a metal source containing nickel can be used to produce a layered active lithium-ion material containing nickel elements.

[0351] In some embodiments, the lithium-containing nickel composite oxide is a lithium-containing nickel-cobalt-manganese composite oxide. In this case, the metal source can comprise a nickel source, a cobalt source, and a manganese source. Suitable dosage ratios of the nickel source, the cobalt source, and the manganese source can be selected based on the molar ratio Ni:Co:Mn in the target chemical formula.

[0352] Typically, the metal source is used to provide the transition metal in the nickel-containing precursor.

[0353] The metal source can also be a soluble salt of the corresponding metal, without any restrictions. For example, in the case of a lithium-containing nickel composite oxide, a soluble nickel salt (e.g., nickel sulfate) can be used as the nickel source; in the case of a lithium-containing nickel-cobalt-manganese composite oxide, a soluble cobalt salt (a non-restrictive example of a soluble cobalt salt is cobalt sulfate) and a soluble manganese salt (a non-restrictive example of a soluble manganese salt is manganese sulfate) can also be used to provide the cobalt and manganese sources, respectively. In the preparation of a nickel-containing precursor of LiNi 0,82 Co 0,12 Mn 0,06For example, nickel sulfate, cobalt sulfate and manganese sulfate in a molar ratio of 82:12:6 can be used as a metal source.

[0354] Non-restrictive examples of complexing agents can include ammonia.

[0355] In some embodiments, the molar ratio of ammonia to the metal element is 1 to 2, with non-limiting examples such as 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, and the like, and can also be selected from a range consisting of any two of the aforementioned values. It is possible to slightly overdose the ammonia to achieve sufficient complexation. The orientation of the primary particles within the secondary particles and the morphology of the secondary particles can be influenced by adjusting the amount of ammonia.

[0356] In some embodiments, the concentration of ammonia in the Co precipitation reaction system is 0.3 mol / L ~1 mol / L, with non-limiting examples such as 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, etc., and can also be selected from the range consisting of any two of the aforementioned concentrations.

[0357] In some embodiments, the precipitating agent is an alkaline reagent. Non-restrictive examples of precipitating agents include alkali metal hydroxides. Non-restrictive examples of alkali metal hydroxides include sodium hydroxide.

[0358] In some embodiments, the reaction temperature at which the co-precipitation reaction is carried out can be in a range of 40°C to 60°C, such as 40°C, 45°C, 50°C, 55°C, 60°C and the like, and can also be selected from a range encompassing any two of the aforementioned temperatures.

[0359] In some embodiments, the pH of the reaction system in which the co-precipitation reaction is carried out can be between 11.2 and 11.8, e.g., 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, and the like, and can also be selected from a range consisting of any two of the aforementioned pH values. By adjusting the pH of the reaction system, the orientation of the primary particles within the secondary particles and the morphology of the secondary particles can be influenced.

[0360] In some embodiments, the reaction temperature at which the co-precipitation reaction is carried out can be in the range of 40°C to 60°C, and the pH value in the range of 11.2 to 11.8. The choice of temperature conditions can affect the growth process of the primary particles and also influence their orientation behavior during this process.

[0361] Dispersion conditions can be achieved by stirring, without any restrictions. In some of these embodiments, the stirring speed is 400 rpm to 1000 rpm, but it can also be 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, and the like, and can also be selected from a range consisting of any two of the aforementioned stirring speeds. The orientation of the primary particles within the secondary particles and the morphology of the secondary particles can be influenced by adjusting the stirring speed.

[0362] After step S100, a laser particle measuring device can be used to perform a test to obtain the particle size and SPAN value of the nickel-containing precursor particles, so that the nickel-containing precursors with a suitable particle size range and SPAN value can be sieved out for step S200.

[0363] S200: Performing the first sintering and the second sintering to obtain an active cathode material containing a lithium-containing nickel composite oxide.

[0364] In some embodiments, S200 comprises the following steps: First sintering of the first mixture containing the precursor and a lithium source in an oxygen-containing atmosphere at a lithium-containing temperature T1 to obtain a first sintered product, and then second sintering of the second mixture containing the first sintered product at a temperature T2 to obtain the active cathode material, which contains a lithium-containing nickel composite oxide; wherein T1 is higher than T2.

[0365] In some embodiments, the lithium source is lithium hydroxide.

[0366] In some embodiments, the molar ratio of nickel-containing precursor to lithium source, based on OH, can be 1:(1.03 to 1.07), e.g., 1:1.03, 1:1.04, 1:1.05, 1:1.06, 1:1.07, and the like, without restriction. Considering the lithium loss during the sintering process, the lithium is generally produced in a slight excess.

[0367] In some embodiments, the steps of performing the first and second sintering include: first, performing the first sintering at a temperature T1 to obtain a first sintered product, and then performing the second sintering at a temperature T2, where T1 > T2. At this point, the first sintering can be referred to as high-temperature sintering and the second sintering as low-temperature sintering.

[0368] In some embodiments, the first sintered product is obtained at the end of the first sintering after comminution, washing and drying.

[0369] In some embodiments, (T2-T1) ≥ 200°C, optionally 200°C ≤ (T2-T1) ≤ 600°C, and further optionally 200°C ≤ (T2-T1) ≤ 400°C. Non-restrictive, (T2-T1) may also be any of the following values ​​or be within a range consisting of any two of the following values: 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, and the like.

[0370] In some embodiments, the sintering time t1 for carrying out the first sintering is greater than the sintering time t2 for the second sintering, where t1>t2.

[0371] In some embodiments, the temperature T1 can be between 700°C and 800°C, such as 700°C, 720°C, 740°C, 750°C, 760°C, 780°C, 800°C, etc., and can be selected from a range consisting of any two of the aforementioned temperatures. Furthermore, the sintering time for the first sintering can be between 15 and 30 hours, such as 15, 16, 18, 20, 22, 24, 25, 26, 28, 30, and the like, and can also be selected from a range consisting of any two of the aforementioned times.

[0372] In some embodiments, the temperature T2 can be between 200°C and 500°C, such as 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, and the like, and can also be selected from a range consisting of any two of the aforementioned temperatures. Furthermore, the sintering time for carrying out the second sintering can be between 3 and 8 hours, such as 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, and the like, and can also be selected from a range consisting of any two of the aforementioned times.

[0373] It is not a restriction to introduce a dopant during the first sintering, and the initial mixture comprising the nickel-containing precursor, the lithium source, and the dopant can be subjected to the first sintering to achieve the doping modification and introduce the dopant into the active cathode material. It is also possible not to introduce a dopant. The type of dopant can be discussed in the examples.

[0374] Without restriction, a coating agent can be introduced during the second sintering process, and the second mixture, comprising the first sintered product and the coating agent, can be subjected to the second sintering to achieve the coating modification required to form the active cathode material with a coating layer that incorporates the coating element provided by the coating agent. It is also possible to omit the coating agent. The nature of the coating element can be discussed in the examples.

[0375] Starting from the nickel-containing precursor, the doping modification and the coating modification can be carried out simultaneously without any limitations.

[0376] The elemental structure and composition of the precursor and active cathode material can be determined using established analytical methods for the structure and composition of active cathode materials. For example, the particle structure can be analyzed using methods such as ion-polished section morphology analysis combined with scanning electron microscopy (SEM), e.g., by analyzing the presence or absence of a coating layer. As a non-limiting example, an IB-19500CP ion cross-section polisher can be used to polish the electrode foil samples to obtain polished samples with sectioned surfaces; furthermore, the samples can be tested with a ZEISS sigma 300 instrument. Subsequently, for example, an inductively coupled plasma spectrometer (ICP instrument, e.g., a ZEISS sigma 300) can be used.Models such as iCAP 7400 are used for the analysis of elemental types and ratios to determine the chemical formulas of the precursor and the active cathode material.

[0377] The size and distribution of the particles in the active cathode material, as well as the size and orientation of the primary particles in the secondary particles, are influenced by the combination of the precursor preparation process and the sintering process, and only some of the relationships between these influences have been described so far. For example, the choice of sintering temperature can also influence the stacking mode of the primary particles, which in turn affects the orientation distribution of the primary particles.

[0378] The aforementioned active cathode material, containing oriented secondary particles, can be obtained using the aforementioned method. In the production of an active cathode material containing, for example, a lithium-containing nickel composite oxide, the growth, stacking, and orientation behavior of the primary particles can be controlled by adjusting one or more parameters, such as the selection of the transition metal element in the metal source, the temperature of the co-precipitation reaction, the pH of the co-precipitation reaction, the amount of complexing agent (e.g., ammonia), the amount of precipitating agent (e.g., sodium hydroxide), the dispersion rate (dispersion methods such as stirring), and the particle size and distribution of the precursor (e.g., D). v50 of the precursor, SPAN value), the sintering process (e.g., the temperature gradient design), the sintering temperature, the sintering time, etc., can be adjusted, which in turn affects the size and morphology of the secondary particles formed, as well as the size, orientation, and orientation distribution of the primary particles within the secondary particles. The angle α1 (the angle formed between the a-axis and the longitudinal direction of the primary particles) and F1 (the number of primary particles with the a-axis and the longitudinal direction forming the angle α1, as a percentage of the number of oriented secondary particles) can be adjusted within the ranges described above. Reference can be made to the exemplary embodiments below. In addition, the way in which the angle α1 deviates from the corresponding longitudinal direction (e.g., clockwise or counterclockwise), the anisotropy index I, can also be adjusted. α1The angle α1 and the like can be adjusted by setting one or more of the parameters mentioned above. The R L / W the primary particles and their distribution parameters (e.g. characteristic parameters such as the R L / W -Mean (R MI ) the inner layer, the R L / W -Mean (R MO (of the outer layer, etc.) can also be adjusted by setting one or more of the aforementioned parameters. R MI <R MO This can be achieved by adjusting the pH value and adding crystal types, etc., whereby it is also possible to achieve that the R L / W -Values ​​of the primary particles increase successively from the center of the oriented secondary particle to its surface.

[0379] Another aspect of the present application provides a cathode foil comprising an active cathode material layer, wherein the active cathode material layer comprises the active cathode material described in the second aspect of the present application.

[0380] A third aspect of the present application provides a power-consuming device comprising at least one of the secondary battery according to the first aspect and the active cathode material according to the second aspect of the present application.

[0381] In some embodiments, the present application further provides a power-consuming device, wherein the power-consuming device comprises a secondary battery according to one of the embodiments. The secondary battery can be used as a power source for the power-consuming device or as an energy storage unit for the power-consuming device. Power-consuming devices include, among others, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, and the like. The mobile device can be, for example, a mobile phone, a laptop, or the like; the electric vehicle can be, for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, and the like, but is not limited to such.The power-consuming device can also be used in military equipment, aerospace and other fields, as well as in energy storage systems such as hydroelectric, thermal, wind and solar power plants.

[0382] Depending on requirements, a secondary battery can be selected as the power-consuming device.

[0383] Fig. Figure 8 shows an example of a power-consuming device 6. The power-consuming device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of the secondary battery of this power-consuming device, a battery pack or battery module can be used.

[0384] Another example of such a device is a mobile phone, a tablet, a laptop, etc. The device usually needs to be light and thin and can use a secondary battery as a power source.

[0385] The following describes some embodiments of the present application. The described embodiments represent only a portion of the embodiments of the present application and not all embodiments. The embodiments explained below are exemplary, serve to illustrate the present application, and cannot be understood as limiting the present application and its application. Based on the embodiments of the present application, all other embodiments that can be obtained by a person skilled in the art without inventive step fall within the scope of protection of the present application.

[0386] Unless otherwise specified in the exemplary embodiments, they correspond to the techniques or conditions described in the relevant literature or the information in the product specification. Unless otherwise stated, the reagents or instruments used are commercially available products or can be synthesized conventionally using commercially available products.

[0387] The following examples describe measurement parameters of the raw material components, which, unless otherwise specified, may exhibit minor deviations within the weighing accuracy range. These are temperature and time parameters that allow for acceptable deviations due to instrumental testing accuracy or operational accuracy.

[0388] In the following examples, the room temperature is defined as 20°C to 30°C.

[0389] The instruments used in the following test and analysis procedures are not limiting examples; the person skilled in the art may use other equipment models or similar methods for the test and analysis. Testing and analysis procedures 1. Structural and elementary analyses

[0390] The analysis is performed using an inductively coupled plasma spectrometer (ICP instrument) to determine the chemical formula.

[0391] Test device: iCAP 7400. 2. Test of D v 50, D v 90, D v 10 and D n 10 and SPAN analysis

[0392] Test device: Laser particle measuring device Mastersizer 3000.

[0393] Procedure: Take a clean beaker, weigh out the appropriate amount of the sample to be tested, add 20 ml of ethanol for dispersion (sample concentration to obtain the desired color: 25% to 30%), and use ultrasound at 250 W for 3 minutes to completely disperse the sample. The sample is placed in the feed tower and circulated with the solution to the optical test system. The particles are irradiated with the laser beam, and the particle size distribution properties can be determined by recording and measuring the energy distribution of the scattered light. Reference according to standard GB / T19077-2016 / ISO 13320:2009.

[0394] Drawing the particle size-volume distribution graph according to the test data, and determining D v 50, D v 90, D v 10 from the particle size-volume distribution graph. SPAN=(D v 90-D v 10) / D v50. Draw the particle size-quantity distribution graph according to the test data and determine D n 10 from the particle size quantity distribution graph.

[0395] Some of the test results can be found in Table 3. 3. Structural observation and statistical analysis of primary particles in secondary particles

[0396] Using focused ion beam electron microscopy or the ion section polisher, the secondary particles in the active cathode material layer of the cathode foil were cut to obtain a cross-sectional view that essentially passes through the center of the secondary particles, and the information of the primary particles in the cross-sectional view was further analyzed by combining it with the test diagram of the scanning electron microscope (SEM).

[0397] (1) Focused ion beam electron microscopy (FEI Scios 2HiVac device) or ion section polisher.

[0398] The secondary particles were cut until the section, which essentially runs through the center of the secondary particles, was exposed for SEM observation. (2) Scanning electron microscope (SEM)

[0399] Equipment: Apreo 2 SEM field emission scanning electron microscope or ZEISS Sigma 300 scanning electron microscope.

[0400] Sample preparation: Cut out a sample of suitable size (e.g. 5 mm x 5 mm) and glue it onto a sample table with conductive adhesive.

[0401] Example test parameters for the Apreo 2 SEM: Acceleration voltage (HV) 2.00 kV, detector T1, OptiPlan mode, probe current of 50 pA. The working distance, magnification, and width of the horizontal field of view can be selected depending on the particle size. An example of the test is shown in Fig.Figure 2 shows a section of an oriented secondary particle. The working distance (WD) of approximately 4.16 mm, the magnification (Mag) of 6500X, and the horizontal field of view (HFW) of 19.5 µm were set for the test in Fig. 2 determined. (3) Analysis of information about primary particles in secondary particles

[0402] Referring to the schematic representation in Fig. 1. Parameters such as α1, the direction of the α1 deviation from the radial direction of the secondary particles, L and W of the primary particles were measured and statistically evaluated to determine parameters such as F1, R L / W , R MI , R MO and I α1 to derive. Some of the analysis results can be found in Tables 2 and 3.

[0403] From the SEM test results of the sections through the center of the secondary particles, the sections showing a complete circumferential contour of the secondary particle section were selected for the information statistics of the primary particles.

[0404] A specific number of N0 primary particles (N0 ≥ 12) were selected, and the circumferential contour of the primary particle section in the micrograph was outlined as an ellipse. The value of the maximum length was measured as a test value for the "diameter of the primary particle." The direction of the maximum length is designated as the direction of the a-axis, and a straight line 1 is determined that passes through the center of the secondary particle and the center of the primary particle. The angle between the a-axis and line 1 is measured as α1; the distance between the two points of intersection of line 1 and the circumferential contour of the primary particle is designated L; a line 2, perpendicular to line 1, is determined, and line 2 and the circumferential contour of the primary particle are designated W. The distance between the two points of intersection is recorded. And R L / W =L / W. It can be applied to Fig. 1 will be referred.

[0405] Based on the distance R from the center of the secondary particle to its surface, the region from the center of the secondary particle (i.e., 0R) to 2 / 3R is defined as the "inner layer," and the region from 2 / 3R to the circumferential contour of the secondary particle (i.e., 1R) as the "outer layer." Based on the cross-sectional contour of the oriented secondary particles, the intersection point between a longest axis and a shortest axis in the cross-section of the oriented secondary particles is assumed to be the center of the oriented secondary particles.

[0406] The center of a primary particle is counted in the inner layer if it falls within the area of ​​the inner layer, in the outer layer if it falls within the area of ​​the outer layer, and in the "inner layer" if the center of the primary particle lies at the boundary between the inner and outer layers.

[0407] Based on the statistical information about the R L / Wthe primary particles in the inner and outer layers can be the R L / W -Average value (R MI ) the inner layer and the R L / W -Average value (R MO ) of the outer layer.

[0408] The number of angles with 15°≤α1≤45° is counted and denoted as N1, then F1 = N1 / N0 × 100%. F1 is the percentage of the number of primary particles that form an angle of 15°≤α1≤45° between the a-axis and the corresponding longitudinal direction in the oriented secondary particles.

[0409] The direction of α1 that deviates from the radial direction of the secondary particles: If α1 deviates clockwise from the straight line L, it is marked as “+” and the count result is N1; if α1 deviates counterclockwise from the straight line L, it is marked as “-” and the count result is N2; if α1 is not within the range of 15°≤α1≤45°, it is marked as “Other”. α1 =N1 / N2. (4) Proportion of the number of oriented secondary particles in the secondary particles.

[0410] Using a randomly selected section with at least 10 secondary particles, the results of the SEM analysis of the section through the center of the secondary particle are used to determine whether it is an oriented secondary particle. If 15° ≤ α1 ≤ 45° and F1 ≥ 60%, an oriented secondary particle is counted; if α1 is not within the above range or F1 < 60%, no oriented secondary particle is counted. Based on the counting results, the percentage of oriented secondary particles is calculated, and this value is used as the test value for the "percentage of oriented secondary particles among the secondary particles P2".

[0411] Some of the results can be found in Table 3. 4. Characterization of the active cathode material(1) Powder density

[0412] The powder compaction density can be determined on-site using conventional methods. Test equipment: Electronic pressure testing device or compression density measuring device.

[0413] Example of the test with the electronic pressure testing device: a certain powder mass m0 is taken and placed in the mold of the electronic pressure testing device, with the base area of ​​the mold being recorded as A, the pressure is set to 4T, the pressure is held for 30 seconds, the height h0 of the resulting powder block is read and the powder compaction density ρ under 4T is calculated according to the formula ρ=m0 / (A0×h0).

[0414] Example of the test with the compact density meter: a specific mass of powder m0 is taken and placed in the special mold for pressing, with the base area of ​​the mold being recorded as A0, then the mold is placed on the compact density meter, pressure is applied to 4T, the pressure is maintained for 30 seconds, the thickness h0 of the powder block is recorded after the pressure has been removed, and the powder compact density ρ under 4T is calculated according to the formula ρ=m0 / (A0×h0).

[0415] Some of the results can be found in Table 3. (2) Test of the solid-phase diffusion coefficient of lithium ions:

[0416] The test procedure for the solid-phase diffusion coefficient of lithium ions for the active cathode material, using the GITT method as an example, is as follows:

[0417] At a test temperature of 25°C, the active cathode material was milled into a powder microelectrode; the powder microelectrode was connected to an electrochemical workstation for Coulomb titration. In this case, the GitT curve was obtained with a pulse current of 20 µA and a titration time of 1 hour with a 4-hour interval. (Note: To compare the effects of pulse current and time, a parallel experiment with 10 µA for 10 minutes can be performed.) The diffusion coefficient D of the lithium ions is calculated using the following formula: D=4π(VmA×F×n)2[I0(dEdx) / (dEdt)]2(t≪L2 / D)

[0418] Here, D is the diffusion coefficient of lithium ions; I0 is the applied pulse current of 20 µA; V mis the molar volume of the active cathode material; F is the Faraday constant; A is the electrode surface area; and n is the number of lithium ion charges. n is 1; dE / dx is the slope of the Coulomb titration curve, i.e., the slope of the open-circuit potential against a concentration at a given concentration on the Li concentration curve in the electrode; dE / d(t1 / 2) is the slope of the polarization voltage against the t1 / 2 curve. For further details, see the following literature: Xie et al., Solid State Ionics, 2007, 178:1218–1224; Yang et al., Electrochimica Acta, 2012, 66:88–93.

[0419] Some of the results can be found in Table 3. 5. Battery performance test(1) Volumetric energy density

[0420] The volume of the electrical core of the secondary battery was specified as V0.

[0421] Capacity test: Charge with 1 / 3C constant current to 3.65V, then charge with 3.65V constant voltage to a current of 0.05C, let it rest for 5 minutes, and then discharge with 1 / 3C to 2.5V to obtain the capacity C0, and the voltage plateau is recorded as U.

[0422] Then the volumetric energy density of the battery is VED=C0×U / V0.

[0423] Some of the results can be found in Table 3. (2) Cycle performance test

[0424] The battery under test was charged at 25°C with a constant current of 1C to a voltage of 4.25V, then charged with a constant voltage of 4.25V to a current of 0.05C, left to stand for 5 minutes, and then discharged with a constant current of 1C to a voltage of 2.8V; the resulting capacity is recorded as the initial capacity C0. The above steps are repeated for the same battery as described above, and the discharged capacity C is recorded simultaneously. n The battery capacity maintenance rate P was recorded after the nth time of the cycle. n =C n / C0×100% after the nth time of the cycle. The cycles are performed until the cell's capacity maintenance rate has dropped to 80%.

[0425] The recorded battery capacity retention rate at 900 cycles can be found in Table 3. Example 11. Production of the active cathode material

[0426] According to the chemical target formula (LiNi 0,82 Co 0,12 Mn 0,06Nickel sulfate hexahydrate, cobalt sulfate heptahydrate, and manganese sulfate monohydrate were dissolved in deionized water to prepare a metal solution with a molar ratio of Ni:Co:Mn of 82:12:6. The metal solution, the complexing agent ammonia, and the precipitating agent sodium hydroxide solution were pumped into the reaction vessel to carry out the cobalt precipitation reaction. The entire reaction process was protected by an inert gas (nitrogen). The temperature of the reaction system was 40°C to 60°C, the pH was 11.2 to 11.8, the molar ratio of ammonia to the metal elements was between 1 and 2, and the stirring speed was 400 rpm to 1000 rpm. At the end of the reaction, the precursor, which is a metal hydroxide, was recovered by washing, drying, and other processes.

[0427] The nickel-containing precursor was sintered to produce an active cathode material with lithium-containing nickel composite oxide: The prepared nickel-containing precursor and the lithium source, lithium hydroxide, were mixed uniformly, and the first sintering was carried out by introducing oxygen (O2) under high-temperature conditions, with a high-temperature sintering temperature of 700°C to 800°C (T1) and a sintering time of 15 to 30 hours (t1); The produced material was crushed, washed, dried, and subjected to other processes to obtain the first sintered product; The first sintered product was subjected to a second low-temperature sintering at a low-temperature sintering temperature of 200°C to 500°C (T2) and a sintering time of 3 to 8 hours (t2) to obtain the ternary active cathode material.

[0428] In this example, the reaction temperature of the co-precipitation process was 50°C, the pH was adjusted to 11.5 ± 0.2, the molar ratio of ammonia to metal elements was 1.2, the stirring speed was 600 rpm, and the nickel-containing precursor and the lithium source, lithium hydroxide, were mixed in a molar ratio of 1:1.05 (based on OH). The high-temperature sintering temperature (T1) was 780°C and the high-temperature sintering time (t1) was 20 hours, the low-temperature sintering temperature (T2) was 400°C and the high-temperature sintering time (t2) was 4 hours. 2. Production of the secondary battery(1) Production of the cathode foil

[0429] The previously prepared active cathode material, conductive carbon black and polyvinylidene fluoride (PVDF), was mixed with N-methylpyrrolidone solvent in a mass ratio of 97.44:1.56:1 to obtain a cathode slurry. This slurry was applied to both surfaces of an aluminum foil and dried in a vacuum oven at 100°C to 120°C for 8 to 10 hours. After cold pressing and cutting, a cathode foil was obtained. The single-sided surface density of the coating was 0.25 g / (1540.25 mm²). 2 ), which is approximately 16.23 mg / cm² 2 corresponded. (2) Production of the anode foil

[0430] Graphite, styrene-polybutadiene rubber, conductive carbon, and sodium carboxymethyl cellulose were added to deionized water in a mass ratio of 96.5:1.8:0.7:1, mixed homogeneously, and an anode slurry was obtained. This anode slurry was applied to both surfaces of the copper foil, dried in a drying oven, and then cold-pressed and slit to produce an anode foil. The one-sided surface density of the coating was 0.16 g / (1540.25 mm²). 2 ), which is approximately 10.39 mg / cm² 2 corresponded. (3) Separator: A conventional polypropylene film (PP film) is selected. (4) Electrolyte solution

[0431] Vinyl carbonate, diethyl carbonate, and dimethyl carbonate were mixed in a volume ratio of 1:1:1, and LiPF6 was dissolved in the aforementioned mixed solvent to obtain the electrolyte solution. The concentration of LiPF6 in this electrolyte solution was 1 mol / L. (5) Assembly of the secondary battery

[0432] In the sequence "separator - anode foil - separator - anode foil," one end of the cathode foil, the anode foil, and the two separators were attached to the discharge roller, and the other end was stacked together and attached to the winding shaft. The winding shaft is rotated by a motor, and the cathode foil, the anode foil, and the two separators are wound to form a wound electrical core (wound electrode assembly).

[0433] The electrode assembly is loaded into an aluminum housing, baked at 80 °C to remove water, then filled with electrolyte and sealed, and then goes through the processes of resting, hot and cold pressing, chemical formation, shaping and capacity testing to obtain the secondary battery.

[0434] Exemplary embodiments 2-5: An active cathode material and a secondary battery were produced essentially according to the same procedure as in Exemplary embodiment 1. The difference is that the active cathode material production step is mainly adjusted by setting one or more of the following parameters: the pH of the co-precipitation reaction system in the precursor production step, the concentration of ammonia as a complexing agent (to control the pH in the range of 11.2 to 11.8, the amount of sodium hydroxide can be adjusted accordingly), the reaction temperature, reaction time and stirring speed of the co-precipitation reaction, the sintering temperature T1 and sintering time t1, the sintering temperature T2 and the sintering time t2 in the precursor sintering step.The most important setting parameters can be found in Table 1, and the parameters not listed in Table 1 can be set accordingly based on the previous description.

[0435] Exemplary embodiment 6: An active cathode material and a secondary battery were produced essentially according to the same process as in Exemplary embodiment 1. The difference is that the nickel-containing precursor is produced in the step of producing the active cathode material by adjusting the molar ratio of the nickel source, the cobalt source, and the manganese source to be 6:2:2 according to LiNi. 0,6 Co 0,2 Mn 0,2 O2 is. Comparative example 1

[0436] An active cathode material and a secondary battery were produced essentially according to the same procedure as in embodiment 1. The difference was that the steps for producing the active cathode material differed, with the pH value being 11.0 ± 0.2, the molar ratio of ammonia to the metal elements being 1.0, the stirring speed being 500 rpm, and the sintering temperature T1 in the precursor production step being 750°C.

[0437] In this comparative example, the active cathode material is obtained with a lower F1; F1 is the percentage of the number of primary particles that form an angle of 15°≤α1≤45° between the a-axis and the corresponding longitudinal direction in the oriented secondary particles. Comparative example 2

[0438] An active cathode material and a secondary battery were produced essentially according to the same procedure as in embodiment 1. The difference lies in the steps for producing the active cathode material, wherein in the precursor production step the temperature of the co-precipitation reaction is 55°C, the pH is 11.2 ± 0.2, the molar ratio of ammonia to metal elements is 1.1, and the stirring speed is 450 rpm; the second sintering is carried out first, followed by the first sintering.

[0439] Production of an active cathode material of lithium-containing nickel composite oxide: The nickel-containing precursor was sintered for 8 hours at 450°C. After comminution, washing, drying, and other processes, it was uniformly mixed with the lithium source lithium hydroxide and sintered for 18 hours at 720°C.

[0440] In this comparative example, an active cathode material is obtained in which most of the primary particles α1 of the secondary particles were small, and according to the statistical results, α1 was less than 10°, i.e., it can generally be assumed that there were no oriented secondary particles.

[0441] The parameters of the active cathode materials produced in embodiments 2-6 and in comparison examples 1-2 can also be found in Table 1. Table 1 number Manufacturing parameters of the active cathode material Production of the precursor Sintering Temperature of the co-precipitation reaction (°C) pH Molar ratio of ammonia to metal elements Stirring speed (rpm) First sintering Second sintering Example 1 50 11,5±0,2 1,2 600 780°C, 20 hours 400°C, 4 hours Example 2 50 11,6±0,2 1,5 500 800°C, 15 hours 450°C, 3 hours Example 3 55 11,5±0,2 1,25 800 760°C, 22 hours 350°C, 6 hours Example 4 40 11,5±0,2 1,6 400 740°C, 24 hours 300°C, 6 hours Example 5 60 11,2±0,2 1,1 1000 700°C, 30 hours 250°C, 8 hours Example 6 As in example 1 Comparative example 1 50 11,0±0,2 1,0 500 750°C, 20 hours 400°C, 4 hours Comparative example 2 55 11,2±0,2 1,1 450 450°C, 8 hours 720°C, 18 hours Test and analysis result

[0442] In embodiments 1-6, an active cathode material is produced using lithium-containing nickel oxides as an example, and according to the results of the elemental analyses, the elemental compositions of the active anode materials essentially agree with the target chemical formula.

[0443] The active cathode materials produced in the above embodiments 1-6 all fulfill the following characteristics: (1) There are oriented secondary particles with 15°≤α1≤45° and F1≥60%, and the oriented secondary particles satisfy F1≥70% in some embodiments, and F1 exceeds 80% in some embodiments; (2) the number of oriented secondary particles in the secondary particles of the active cathode material was P2≥75% (fulfilling both P2≥70% and P2≥60%), and P2≥80% in most embodiments, furthermore P2 ≥ 90% is also fulfilled, and in some embodiments P2 exceeds 95%; (3) According to the statistical results, the R L / W in the oriented secondary particles all R L / W ≤ 4, and all are in the range of 0.95 ≤ R L / W ≤ 4, and the average value of R L / W All values ​​are in the range of 1.5 to 2.5, and the average value of R L / WIn some embodiments, the value is in the range of 1.5 to 2.0; (4) According to the statistical results, all R MI <R MO , i.e., the average value of R L / W The inner layer's value is lower than the average value of R. L / W of the outer layer; each embodiment satisfies R MI <1.8 and R MO ≥1.8, and most of the embodiments meet 1.3 ≤R MI <1.8 and 1.8 ≤R MO ≤2.3; The embodiments satisfy R L / W the outer layer in the range of 1, 2 to 4 and R L / W the inner layer in the range of 0.95 ≤ R L / W ≤ 2.8, and the majority of embodiments meet R L / W of at least 80% of the number of primary particles in the outer layer in the range of 1.4 to 4 and R L / W of at least 80% of the number of primary particles in the inner layer in the range of 0.95 to 2.0; (5) According to the statistical results, the anisotropy index Iα1 of the angle α1 0.4 ≤I α1 ≤ 2.5, and most embodiments meet 0.5 ≤ I α1 ≤ 2.0; (6) The active cathode material has a D v 50 particles ranging from 8 µm to 11 µm, at least 80% of the primary particles in the oriented secondary particles have a diameter in the range of 100 nm to 1600 nm, and the active cathode material meets 1.1 ≤ SPAN ≤ 1.4; Some embodiments meet the requirement that the D v 50 of the active cathode material is 9 µm to 11 µm, the diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 400 nm to 1500 nm and in the active cathode material is 1.2 ≤ SPAN ≤ 1.3; (7) According to the statistical results, the active cathode material meets the requirements of 15 µm ≤ D v 90 ≤ 18 µm, 4 µm ≤ D v 10 ≤ 6 µm, and D n 10 ≥ 2 µm; and some embodiments further satisfy 16 µm ≤ D v 90 ≤ 17 µm, 4.5 µm ≤ Dn 10 ≤ 5.5 µm.

[0444] In embodiment 1, the statistical results of the L-value, the W-finger and the direction of the deviation of α1 from the corresponding longitudinal direction of the primary particles in the inner layer and the outer layer in one of the oriented secondary particles are shown according to Fig. 2 shown in Table 2. The following information can be obtained: R L / W They all lie in the range of 0.95 to 4, the average value of R L / W is 1.86, R MI is 1.51 µm, and R MO is 2.05 µm, which is R MI <R MO fulfilled; The number of primary particles in the outer layer with R L / W in the range of 1.4 to 4 is approximately 81%, and the number of primary particles in the inner layer is R L / W In the range of 0.95 to 2.0, the percentage is approximately 83%;

[0445] The inner layer has an L-average value of less than 700 nm, the outer layer has an L-average value of 783.5 nm (which is greater than or equal to 720 nm and also greater than or equal to 750 nm), and the inner layer has an L-average value of 649.4 nm (which is less than or equal to 700 nm and also less than or equal to 660 nm), and I α1 is approximately 1.75. Table 2 Number of primary particles Direction of deviation of α1 from its corresponding longitudinal direction L W Distribution position of the primary particles in the secondary particles Statistical value of R L / W 1 Miscellaneous 628.5 nm 506.4 nm Inside 1,24 2 + 871.4 nm 548.7 nm Inside 1,59 3 Miscellaneous 535.6 nm 543.9 nm Inside 0,98 4 Miscellaneous 557.5 nm 410.6 nm Inside 1,36 5 + 500 nm 318.0 nm Inside 1,57 6 Miscellaneous 803.4 nm 346.0 nm Inside 2,32 7 + 1,323 µm 360.2 nm Outside 3,67 8 - 963.8 nm 314.2 nm Outside 3,07 9 + 459.3 nm 353.4 nm Outside 1,30 10 Miscellaneous 585.3 nm 436.7 nm Outside 1,34 11 - 604.3 nm 392.9 nm Outside 1,54 12 + 792.0 nm 508.3 nm Outside 1,56 13 - 656.5 nm 280.1 nm Outside 2,34 14 + 639.7 nm 422.8 nm Outside 1,51 15 Miscellaneous 479.5 nm 282.4 nm Outside 1,70 16 - 1,21 µm 405.9 nm Outside 2,98 17 + 905.4 nm 593.9 nm Outside 1,52

[0446] In Table 2: “Columns for the direction of α1 deviating from the corresponding longitudinal direction”, “+” corresponds to the direction clockwise, “-” to the direction counterclockwise and “other” means that the angle is not in the range of 15° to 45°.

[0447] The active cathode materials produced in embodiments 1-6 all have a high compression density, as can be seen from Table 3.

[0448] The solid-phase diffusion coefficients (25°C) of the lithium ions of the active cathode materials produced in embodiments 1-6 were all in the range of 1×10 -9 cm 2 -s -1 up to 8×10 -9 cm 2 -s -1 , including 2.5×10 -9 cm 2 -s -1 In embodiment 1. In both comparative example 1 and comparative example 2, the values ​​are below 1×10 -9 cm 2 -s -1 , with 5.2×10 -10 cm 2 -s -1 in comparative example 1 and 1.8×10 -10 cm 2 -s -1 See comparative example 2. Reference can be made to Table 3.

[0449] The secondary batteries produced in embodiments 1-6 all exhibit high energy density, good kinetic performance and a long cycle life.

[0450] In the active cathode material produced in Comparison Example 1, F1 is lower; in the active cathode material produced in Comparison Example 2, there are almost no oriented secondary particles, and according to the test results, α1 is less than 10°, indicating that the primary particles are mainly distributed along the radial direction of the secondary particles. The kinetic power, energy density, and cycle power of the secondary batteries produced using Comparison Example 1 and Comparison Example 2 all decreased to varying degrees.

[0451] The results of some test analyses for some embodiments are summarized in Table 3. Table 3 number Active cathode material Battery power Oriented secondary particles Material test Energy density Cycle performance There is an angle α1 in the following area F1 compliant F1 compliant P2 fulfilled Powder density below 4T (g / cm³) 3 ) Solid-phase diffusion coefficients of lithium ions at 25°C (10 -9 cm 2 -s -1 ) Volumetric energy density (Wh / L) Battery capacity retention rate after 900 cycles Example 1 15°-45° 64% 92% 1,3 3,45 2,5 693 95% Example 2 15°-45° ≥70% ≥80% 1,4 3,41 1-8 681 96% Example 3 15°-45° ≥90% ≥90% 1,2 3,40 685 93% Example 4 15°-40° ≥60% ≥60% 1,1 3,35 689 90% Example 5 15°-45° ≥65% ≥75% 1,4 3,42 679 93% Comparative example 1 15°-35° Approximately 30% Approximately 42% 1,3 3,35 0,52 674 89% Comparative example 2 α1 are less than 10° 0 / 1,5 3,34 0,18 671 85%

[0452] Table 3 shows that the powder compaction density was tested under 4T using an electronic pressure testing device.

[0453] In the above description of the various embodiments and exemplary embodiments, the differences between them are generally highlighted, which can be referenced with regard to similarities or commonalities and which will not be repeated here for the sake of brevity. The various technical features of the embodiments and exemplary embodiments described above can be combined in any combination, and all possible combinations of the various technical features of the exemplary embodiments described above are not described for the sake of brevity; however, as long as there are no contradictions in the combinations of these technical features, they should be considered to be within the scope of this description.

[0454] It should be noted that the present application is not limited to the embodiments and exemplary embodiments mentioned above. The embodiments and exemplary embodiments mentioned above are merely examples, and embodiments and exemplary embodiments within the scope of the technical solution of the present application that have essentially the same composition as the technical idea and have the same effect are included in the technical scope of the present application. The embodiments and exemplary embodiments described above express only some embodiments and exemplary embodiments of the present application, which are described in a more detailed manner, but are not to be understood as limiting the scope of the application.Furthermore, within the scope of the present application, the present application also includes other possibilities for constructing the embodiments or exemplary embodiments by combining some of the constituent elements of the embodiments or exemplary embodiments and applying various deformations to the embodiments that a person skilled in the art can imagine without departing from the subject matter of the present 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 2024109275446

[0001] Cited non-patent literature

[0000] Xie et al., Solid State Ionics, 2007, 178:1218-1224

[0418] Yang et al., Electrochimica Acta, 2012, 66:88-93

[0418]

Claims

[1] Secondary battery comprising a cathode foil, wherein the cathode foil comprises an active cathode material, wherein the active cathode material comprises secondary particles, the secondary particles being an agglomerate comprising a plurality of primary particles; wherein the primary particles comprise an active cathode substance; wherein in each of the secondary particles the direction pointing from a center of the secondary particle to its surface is called the X-direction; wherein the X-direction passing through the center of one of the primary particles is called the longitudinal direction; wherein in each of the primary particles the longest axis of the primary particle is called the a-axis; wherein the secondary particles comprise oriented secondary particles; wherein in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1≥60%. [2] Secondary battery according to claim 1, wherein the angle α1 is obtained as follows: in a section passing through the center of the oriented secondary particles, the direction pointing from the center of the oriented secondary particles to the surface of the oriented secondary particles is considered the X-direction, wherein the X-direction passing through the center of the section of a primary particle is considered the longitudinal direction corresponding to the primary particle, wherein the longest axis in the section of the primary particle is referred to as the a-axis, wherein the angle α1 is obtained on the basis of the angle formed by the a-axis with the corresponding longitudinal direction. [3] Secondary battery according to claim 1 or 2, wherein F1≥64%. [4] Secondary battery according to any one of claims 1 to 3, wherein the percentage of the number of oriented secondary particles in the secondary particles is referred to as P2, wherein P2≥60% is satisfied. [5] Secondary battery according to claim 4, wherein P2≥75%. [6] Secondary battery according to any one of claims 1 to 5, wherein the length value of the primary particles along the longitudinal direction is designated as L, wherein the length value of the primary particles along a direction perpendicular to the longitudinal direction is designated as W, wherein the ratio of L to W in the primary particles is designated as R L / W is designated; wherein in the oriented secondary particles R L / W the primary particle is less than or equal to 4. [7] Secondary battery according to claim 6, wherein the L-value, the W-value and the R L / WThe value is obtained as follows: in a section passing through the center of the oriented secondary particles, the direction pointing from the center of the oriented secondary particles to the surface of the oriented secondary particles is considered the X-direction, wherein the X-direction passing through the center of the section of a primary particle is considered the longitudinal direction corresponding to the primary particle, wherein the L-value is determined based on the length value of the primary particle along the corresponding longitudinal direction, wherein the W-value is determined based on the length value of the primary particle along the direction perpendicular to the corresponding longitudinal direction, wherein an R L / W The value is determined based on the ratio obtained by dividing the L-value by the W-value. [8] Secondary battery according to claim 6 or 7, wherein the active cathode material has at least one of the following features: In the oriented secondary particles, the RL / W value of the primary particles equals 0. <R L / W ≤4; In the oriented secondary particles, the average value of R is L / W of the primary particles 1.5 to 2.

5. [9] Secondary battery according to any one of claims 6 to 8, characterized by , that the active cathode material exhibits at least one of the following characteristics: In the oriented secondary particles, the RL / W value of the primary particles equals 0.

95. <R L / W ≤4; In the oriented secondary particles, the average value of R is L / W of the primary particles 1.5 to 2.

0. [10] Secondary battery according to any one of claims 6 to 9, wherein the distance from the center to the surface of the oriented secondary particles is designated as R; wherein a portion from the center of the oriented secondary particles up to a position 2 / 3R from the center is designated as the inner layer, while a portion from a position 2 / 3R from the center to the surface of the oriented secondary particles is designated as the outer layer; wherein the average value of R in the oriented secondary particles L / W the inner layer as R MI is designated, while the average value of R L / W the outer layer as R MO is denoted, where R MI <R MO . [11] Secondary battery according to claim 10, wherein the active cathode material has one or more of the following features: in the oriented secondary particles is R MI <1.8 and R MO ≥1.8; in the oriented secondary particles, R fulfills L / W the outer layer 1.2≤R L / W ≤4 and R L / W the inner layer 0.95≤R L / W ≤2.

8. [12] Secondary battery according to claim 10 or 11, wherein the active cathode material has one or more of the following features: in the oriented secondary particles, 1.3 ≤ R MI ≤1.8, 1.8≤R MO ≤2.3; in the oriented secondary particles, R fulfills L / W of at least 80% of the primary particles in the outer layer 1.4≤R L / W ≤4, and R L / W of at least 80% of the primary particles in the inner layer 0.95≤R L / W ≤2.

0. [13] Secondary battery according to any one of claims 6 to 12, wherein in the oriented secondary particles of the R L / W -Value of the primary particles increases successively from the center of the oriented secondary particles to the surface of the oriented secondary particles. [14] Secondary battery according to any one of claims 1 to 13, wherein the anisotropy index of the angle α1 is I α1 referred to as the number of primary particles in which the a-axis of the oriented secondary particles forms an angle α1 with the longitudinal direction, where 0.4≤I α1 ≤2.5; wherein in a section passing through the center of the oriented secondary particles, the angle α1 of the a-axis, deviating from the corresponding longitudinal direction clockwise, is referred to as a positive angle, while the angle α1 of the a-axis, deviating from the corresponding longitudinal direction counterclockwise, is referred to as a negative angle, wherein I α1 The ratio of the number of positive angles to the number of negative angles. [15] Secondary battery according to claim 14, wherein 0.5≤I α1 ≤2.

0. [16] Secondary battery according to any one of claims 1 to 14, wherein the active cathode material has one or more of the following features: the active cathode material exhibits D v 50 from 8 µm to 11 µm; The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm, where the diameter of the primary particles refers to a maximum length in each direction of the length of the primary particles; The particle size distribution parameter SPAN of the active cathode material corresponds to the following formula: SPAN=(D v 90-D v 10) / D v 50, where 1.1≤SPAN≤1.

4. [17] Secondary battery according to claim 16, wherein the active cathode material has one or more of the following features: the active cathode material exhibits D v 50 from 9 µm to 11 µm; The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 400 nm to 1500 nm; SPAN of the active cathode material meets 1.2≤SPAN≤1.

3. [18] Secondary battery according to any one of claims 1 to 17, wherein the active cathode material has one or more of the following features: D v 90% of the active cathode material meets 15µm≤D v 90≤18µm; D v 10 of the active cathode material meets 4µm≤D v 10≤6µm; D n 10 of the active cathode material fulfills D n 10≥2µm. [19] Secondary battery according to claim 18, wherein the active cathode material has one or more of the following features: D v 90% of the active cathode material meets 16µm≤D v 90≤17µm; D v 10 of the active cathode material meets 4.5µm≤D v 10≤5.5µm. [20] Secondary battery according to any one of claims 1 to 19, wherein in the oriented secondary particles the active cathode material comprises a layered active lithium ion material. [21] Secondary battery according to any one of claims 1 to 20, wherein the active cathode substance in the oriented secondary particles comprises a lithium-containing nickel composite oxide. [22] Secondary battery according to claim 21, wherein the molar ratio of nickel element and oxygen element in the lithium-containing nickel composite oxide is Q Ni / O is denoted where 0.3≤Q Ni / O ≤0.

5. [23] Secondary battery according to claim 21 or 22, wherein the oriented secondary particles have one or more of the following features: In the oriented secondary particles, 0.4 ≤ Q holds true. Ni / O ≤0.5; The lithium-containing nickel composite oxide comprises at least one of a Co element and one M element, wherein the M element is at least one of a Mn element and one Al element; The lithium-containing nickel composite oxide comprises a dopant element, wherein Q Ni / O <0.5, wherein the doping element comprises at least one of the elements Zr, Al, B, Sr and Ca; at least one part of the primary particles comprises a particle body and a coating layer arranged on at least one part of the surface of the particle body, wherein the particle body comprises a lithium-containing nickel composite oxide, and wherein the coating layer comprises at least one of the elements Zr, Al, B, Sr and Ca. [24] Secondary battery according to any one of claims 21 to 23, wherein in the oriented secondary particles the active cathode substance comprises one or more of a lithium nickel cobalt manganese oxide, a lithium nickel cobalt aluminum oxide and a modified form thereof, wherein the modified form comprises one or more of a doping modification and a coating modification, wherein the dopant used for the doping modification comprises at least one of the elements Zr, Al, B, Sr and Ca, while the coating element used for the coating modification comprises at least one of the elements Zr, Al, B, Sr and Ca; wherein the molar ratio R Ni / O of the nickel element and the oxygen element in the active cathode substance 0.4≤R Ni / O ≤0.5 is fulfilled. [25] Secondary battery according to claim 24, wherein the active cathode material has one or more of the following features: the active cathode material exhibits D v 50 from 8 µm to 11 µm; The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 100 nm to 1600 nm; The particle size distribution parameter SPAN of the active cathode material corresponds to the following formula: SPAN=(D v 90-D v 10) / D v 50, where 1.1≤SPAN≤1.

4. [26] Secondary battery according to claim 25, wherein the active cathode material has one or more of the following features: the active cathode material exhibits D v 50 from 9 µm to 10 µm; The diameter of at least 80% of the number of primary particles in the oriented secondary particles is in the range of 400 nm to 1500 nm; SPAN of the active cathode material meets 1.2≤SPAN≤1.

3. [27] Secondary battery according to any one of claims 24 to 26, wherein the distance from the center to the surface of the oriented secondary particles is designated as R; wherein a part from the center of the oriented secondary particles up to a position 2 / 3R from the center is designated as the inner layer, while a part from a position 2 / 3R from the center to the surface of the oriented secondary particles is designated as the outer layer; wherein in the oriented secondary particles the inner layer has an average value of L less than or equal to 700 nm and the outer layer has an average value of L greater than or equal to 720 nm; wherein the length value of the primary particle along the longitudinal direction is denoted as L, wherein the distance from the center to the surface of the oriented secondary particles is denoted as R; wherein a part from the center of the oriented secondary particles to a position 2 / 3R from the center is denoted as the inner layer, while a part from a position 2 / 3R from the center to the surface of the oriented secondary particles is denoted as the outer layer. [28] Secondary battery according to claim 27, wherein in the oriented secondary particles the inner layer has an average value of L less than or equal to 660 nm and the outer layer has an average value of L greater than or equal to 750 nm. [29] Secondary battery according to any one of claims 1 to 28, wherein the secondary battery further comprises an anode foil, a separator and an electrolyte solution, wherein the separator is arranged between the cathode foil and the anode foil. [30] Secondary battery according to any one of claims 1 to 29, wherein the secondary battery is a lithium-ion secondary battery. [31] Active cathode material, wherein the active cathode material comprises secondary particles, the secondary particles being an agglomerate comprising a plurality of primary particles; wherein the primary particles comprise an active cathode substance; wherein in each of the primary particles the longest axis of the primary particles is called an a-axis; wherein in each of the secondary particles the direction pointing from the center of the secondary particle to its surface is called the X-direction; wherein the X-direction passing through the center of each of the primary particles is called the longitudinal direction; wherein the secondary particles comprise oriented secondary particles; wherein in the oriented secondary particles the percentage of the number of primary particles in the oriented secondary particles in which the a-axis forms an angle α1 with the longitudinal direction is called F1, relative to the total number of primary particles in the oriented secondary particles, where 15°≤α1≤45° and F1>60%. [32] Active cathode material according to claim 31, characterized by that it is an active cathode material in a secondary battery according to one of claims 2 to 28. [33] Power-consuming device, characterized by , comprising at least one secondary battery according to any one of claims 1 to 30 and an active cathode material according to claim 31 or 32.

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