Battery cell, battery device, power-consuming device and energy storage device

Abstract

Battery cell comprising an electrode assembly and a housing body, wherein the electrode assembly is contained in the housing body and the housing body is made of a pouch material; wherein the electrode arrangement comprises a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are arranged stacked alternately; wherein the negative electrode sheet comprises a negative electrode current collector, wherein the negative electrode current collector comprises a negative electrode current collector section, wherein the edge region of the negative electrode current collector section is provided with a chamfer; wherein the positive electrode sheet comprises a positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode current collector section and a positive electrode tab arranged on one side of the positive electrode current collector section extending along a first direction, the first direction being perpendicular to the thickness direction of the battery cell;and wherein the positive electrode sheet further comprises a positive electrode film layer arranged on at least one side of the positive electrode current collection section in the thickness direction of the battery cell, wherein the positive electrode film layer comprises a positive electrode active material layer as well as a first insulating layer and a second insulating layer arranged on the two opposite sides of the positive electrode active material layer in the first direction, wherein the first insulating layer is arranged on a side of the positive electrode active material layer adjacent to the positive electrode tab, and the second insulating layer is arranged on a side of the positive electrode active material layer away from the positive electrode tab; and wherein ; In the fully discharged state of the battery cell, the one-sided areal density of the positive electrode active material layer is greater than or equal to 320 mg / 1540.25 mm². 2 is.

Description

Cross-references

[0001] The present application refers to Chinese patent application No. 202510992931.2 entitled “Battery cell, battery device, power-consuming device and energy storage device”, filed on July 18, 2025, which is hereby incorporated by reference in its entirety. Technical field

[0002] The present application relates to the field of battery technology and in particular to a battery cell, a battery device, a power-consuming device and an energy storage device. State of the art

[0003] In recent years, battery cells have been widely used in energy storage systems for hydroelectric, coal, wind and solar power plants, as well as in many different fields such as electric hand tools, electric bicycles, electric motorcycles, electric vehicles, military equipment and aerospace.

[0004] With growing market demand for greater range and longer battery lifespans, higher demands are being placed on battery processing efficiency and cycle life. However, with current technology, it is difficult to improve both of these performance characteristics simultaneously. Finding a balance between these two has become a pressing technical challenge that needs to be addressed in this field. Disclosure of the invention

[0005] In light of the above-mentioned topic, the present application aims to provide a battery cell that ensures both high processing yield and good cycle stability.

[0006] A first aspect of the present application provides a battery cell comprising an electrode assembly and a housing body, wherein the electrode assembly is received in the housing body and the housing body is made of a pouch material. The electrode assembly comprises a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are arranged alternately stacked. The negative electrode sheet comprises a negative electrode current collector, wherein the negative electrode current collector includes a negative electrode current collector section, the edge region of the negative electrode current collector section being chamfered.The positive electrode sheet comprises a positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode current collector section and a positive electrode tab arranged on one side of the positive electrode current collector section extending along a first direction, the first direction being perpendicular to the thickness direction of the battery cell.The positive electrode sheet further comprises a positive electrode film layer arranged on at least one side of the positive electrode current collection section in the thickness direction of the battery cell. The positive electrode film layer comprises a positive electrode active material layer as well as a first insulating layer and a second insulating layer arranged on the two opposite sides of the positive electrode active material layer in the first direction. The first insulating layer is arranged on a side of the positive electrode active material layer adjacent to the positive electrode tab, and the second insulating layer is arranged on a side of the positive electrode active material layer away from the positive electrode tab. In the fully discharged state of the battery cell, the one-sided areal density of the positive electrode active material layer is 320 mg / 1540.25 mm². 2 .

[0007] In the prior art, the insulating layer is typically arranged only on the side of the electrode tab to mitigate the risk during electrode tab processing. In the embodiments of the present application, an insulating layer is also arranged on a side of the positive electrode active material layer that is away from the positive electrode tab. This reduces the influence of the stress concentration at the corners of the electrode tab on the distance between the positive electrode active material layers. Consequently, it is possible to reduce the risk of lithium plating in the battery without providing a chamfer on the positive electrode sheet, thereby ensuring both high processing yield and good cycle stability in the battery cell.

[0008] The positive electrode active material layer within the aforementioned area indicates that the positive electrode sheet has a higher active material loading, which positively impacts the increase in the volume energy density of the battery cell. However, the applicant has found that chamfering the highly loaded positive electrode sheet to reduce the voltage concentration causes the positive electrode active material within the chamfered area to loosen or even detach under external force. This increases the likelihood of exposing the current collector of the positive electrode sheet, which negatively affects the battery's cycle performance. Therefore, in the embodiments of the present application, the positive electrode sheet is not chamfered.The positive electrode film layer comprises a positive electrode active material layer and insulating layers arranged on the two opposite sides of the positive electrode active material layer in the first direction. This configuration is particularly suitable for a battery cell with a high active material loading and enables a balance between high volume energy density, processing yield, and good cycle stability of the battery cell.

[0009] In any embodiment, the dimension D1 of the first insulating layer in the first direction is 1 mm to 2.5 mm.

[0010] The dimension D1 of the first insulating layer in the first direction is in the range of 1 mm to 2.5 mm. This effectively reduces the risk during the processing of the electrode tab and improves the processing yield of the battery. Furthermore, the first insulating layer contributes to the distribution of stresses at the corners, thus improving the cycle stability of the battery cell.

[0011] In any embodiment, the dimension D1 of the first insulating layer in the first direction is 1 mm to 2 mm.

[0012] A D1 thickness in the range of 1 mm to 2 mm contributes to further improving the processing yield and cycle life of the battery cell. At the same time, it helps to reduce the space required by the first insulating layer relative to the positive electrode active material layer, thereby increasing the volume energy density of the battery cell.

[0013] In any embodiment, the dimension D2 of the second insulating layer in the first direction is 1 mm to 4.5 mm.

[0014] The dimension D2 of the second insulating layer in the first direction, which lies between 1 mm and 4.5 mm, enables effective stress distribution from the casing to the positive electrode current collection section. This reduces the abnormal spacing changes caused by stress concentration at the corners and edges of the positive electrode sheet, thereby improving the cycle performance of the battery cell.

[0015] In any embodiment, the dimension D2 of the second insulating layer in the first direction is 2 mm to 3 mm.

[0016] A D2 thickness in the range of 2 mm to 3 mm contributes to further improving the cycle performance of the battery cell. At the same time, it helps to reduce the space required by the second insulating layer relative to the positive electrode active material layer, thereby increasing the volume energy density of the battery cell.

[0017] In any embodiment, the material of the first insulating layer and the material of the second insulating layer each independently comprise one or more of aluminium oxide, zirconium oxide and titanium oxide.

[0018] The material of the first insulating layer and the material of the second insulating layer comprise the aforementioned materials, which, on the one hand, help to reduce the stress concentration at the right-angled corners and edges of the electrode arrangement. On the other hand, as insulating materials, they help to reduce the likelihood of burrs created when chamfering the negative electrode sheet overlapping with the positive electrode sheet, thereby improving the cycle life and safety performance of the battery.

[0019] In any embodiment, the material of the first insulating layer and the material of the second insulating layer each comprise aluminium oxide.

[0020] In any embodiment, the chamfer comprises an R-chamfer or a C-chamfer.

[0021] The R-chamfer is a rounded chamfer that achieves a smooth transition, resulting in uniform stress distribution and a reduction in stress concentration points. However, this requires machining with a rounding tool of a specific radius, leading to higher tooling costs. Furthermore, tool changes for different radius roundings can increase production costs and times. The C-chamfer is a 45° chamfer angle, which removes identical dimensions from adjacent surfaces. This can be achieved with a standardized helical chamfer tool or by adjusting the tool's feed angle. The tool offers greater versatility and is relatively less expensive, although its effectiveness in reducing stress concentrations is less pronounced than that of the R-chamfer.

[0022] In any embodiment, the chamfer is an R-chamfer.

[0023] In the embodiments of the present application, the chamfer of the negative electrode sheet comprises an R-chamfer. This allows for a further reduction of the voltage concentration at the right-angled corners and edges of the negative electrode sheet, thereby reducing the probability of lithium plating of the negative electrode sheet. Consequently, this further improves the cycle performance of the battery cell.

[0024] In any embodiment, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction satisfies the condition 2 mm ≤ OH1 ≤ 6 mm.

[0025] The dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction facilitates the provision of adequately sized space on the positive electrode sheet for the arrangement of the first and second insulating layers, thereby enabling a further improvement in the cycle performance of the battery cell. Simultaneously, the dimension of the negative electrode film layer is larger than that of the positive electrode film layer, which helps to provide sufficient lithium intercalation sites on the negative electrode sheet, thus reducing the likelihood of lithium plating of the negative electrode sheet and further improving the cycle performance of the battery cell. Furthermore, an excessively large OH1 can impair the loading of positive electrode active material.In the embodiments of the present application, OH1 facilitates the improvement of the cycle performance of the battery cell within the above-mentioned range while simultaneously ensuring the energy density.

[0026] In any embodiment, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction satisfies the condition 2 mm ≤ OH1 ≤ 5 mm.

[0027] In the embodiments of the present application, OH1 contributes within the above-mentioned range to further improving the cycle performance of the battery while simultaneously ensuring the energy density.

[0028] In any embodiment, the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer satisfies the condition OH1 - (D1 + D2) = 0 mm, where D1 is the dimension of the first insulating layer in the first direction and D2 is the dimension of the second insulating layer in the first direction.

[0029] In the prior art, a technical solution for chamfering the positive electrode is typically used to reduce the stress concentration at the corners of the positive electrode sheet. However, this technical solution leads to the loss of some of the positive electrode active material, thereby reducing the volume energy density of the battery. In the embodiments of the present application, the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer satisfies the condition OH1 - (D1 + D2) = 0 mm, which means that the negative electrode film layer and the positive electrode film layer have the same dimensions. The dimensional difference between the negative electrode film layer and the positive electrode active material layer is used to form the first insulating layer and the second insulating layer.On the one hand, this structure helps to improve space utilization within the battery assembly and thus increase the energy density of the battery cell. On the other hand, the negative electrode current collector is chamfered, while the positive electrode current collector is not. The negative electrode film layer has the same dimensions as the positive electrode film layer. This allows the first and second insulating layers in the positive electrode film layer to effectively distribute the stresses generated by the contraction of the casing. This reduces the stress concentration at the edges of the negative electrode sheet and thus further improves the cycle performance of the battery cell.

[0030] In any embodiment, the dimensional difference OH2 between the negative electrode film layer and the positive electrode active material layer in the second direction satisfies the condition 1 mm ≤ OH2 ≤ 3 mm, where any two of the first direction, the second direction and the thickness direction of the battery cell are perpendicular to each other.

[0031] In the embodiments of the present application, maintaining the dimensional difference OH2 between the negative electrode film layer and the positive electrode active material layer within the aforementioned range facilitates the provision of sufficient lithium intercalation sites on the negative electrode sheet. This helps to reduce the probability of lithium plating of the negative electrode sheet and thereby improve the cycle performance of the battery cell.

[0032] In any embodiment, the areal density of the positive electrode active material layer on one side is 320 mg / 1540.25 mm² when the battery cell is completely discharged. 2 up to 400 mg / 1540.25 mm 2 .

[0033] In any embodiment, when the battery cell is completely discharged, the density of the positive electrode active material layer is greater than or equal to 2.3 g / cm³. 3 .

[0034] A high compaction density contributes to increasing the loading of positive electrode active material on the positive electrode sheet; a low compaction density increases the porosity of the film layer and thereby improves the liquid retention properties. In the embodiments of the present application, the compaction density of the positive electrode film layer within the aforementioned range, when the battery cell is in a fully discharged state, facilitates the achievement of both a higher loading of active material and a suitable pore structure. This improves the liquid retention rate of the electrode sheet and reduces the polarization impedance, thereby improving the cycle performance and capacity utilization of the battery.

[0035] In any embodiment, the compaction density of the positive electrode film layer in the fully discharged state of the battery cell is 2.3 g / cm³.3 up to 2.6 g / cm³ 3 .

[0036] In any embodiment, the positive electrode active material layer comprises a positive electrode active material, wherein the positive electrode active material comprises a lithium-containing transition metal oxide particle and a lithium-containing transition metal phosphate particle.

[0037] Lithium-containing transition metal oxides have a higher capacity per gram. In the embodiments of the present application, the positive electrode active material comprises a lithium-containing transition metal oxide, which contributes to improving the energy density of the battery cell. Lithium-containing transition metal phosphates exhibit good cycle performance. In the embodiments of the present application, the positive electrode active material comprises a lithium-containing transition metal phosphate, which contributes to improving the cycle performance of the battery cell.

[0038] In any embodiment, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles is 5:5 to 9:1.

[0039] In the embodiments of the present application, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles within the above-mentioned range contributes to ensuring the cycle performance of the battery cell and the energy density.

[0040] In any embodiment, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles is 6:4 to 8:2.

[0041] In the embodiments of the present application, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles within the above-mentioned range contributes to further improving the cycle performance of the battery cell while simultaneously ensuring the energy density.

[0042] In any embodiment, the lithium-containing transition metal oxide particle comprises a component represented by the following general formula: Li a1 Ni x1 Co y1 M1 z1 M2 w1 O 2-b1 Formula 1 where M1 includes one or more of Mn and Al, M2 includes one or more of Zr, B, Mg, Ti, W, Mo, Nb, Ta, Sr, Sb and K, where 0.8 ≤ a1 ≤ 1.2, 0 ≤ x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ z1 ≤ 1, 0 ≤ w1 ≤ 0.1, -0.1 ≤ b1 ≤ 0.1.

[0043] If the positive electrode active material layer includes lithium-containing transition metal oxides of the types mentioned above, the capacity per gram of the positive electrode active material can be further increased, thereby further improving the energy density of the battery cell.

[0044] In any embodiment, the lithium-containing transition metal phosphate particle comprises a component represented by the following general formula: Li x A y Me a M b P 1-c X c Y z Formula II where 0.1 ≤ x ≤ 1.3, 0 ≤ y ≤ 1.3 and 0.8 ≤ x + y ≤ 1.3; 0.9 ≤ a ≤ 1.5, 0 ≤ b ≤ 0.5 and 0.9 ≤ a + b ≤ 1.5; 0 ≤ c ≤ 0.5; 3 ≤ z ≤ 5; A includes one or more of Na, K and Mg; Me includes one or more of Mn, Fe, Co and Ni; M includes one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La and Ce; X comprises one or more of S, Si, Cl, B, C and N; and Y comprises one or more of O and F.

[0045] The lithium-containing transition metal phosphate, which comprises the component represented by the general formula above, exhibits good thermal and cycle stability, thereby contributing to improved safety and cycle performance of the battery.

[0046] In any embodiment, the lithium-containing transition metal phosphate particle comprises one or more of lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate fluoride, lithium manganese iron phosphate, lithium iron phosphate fluoride, lithium manganese iron phosphate fluoride and modified materials thereof.

[0047] In any embodiment, the lithium-containing transition metal phosphate comprises one or more lithium manganese iron phosphate and its modified materials.

[0048] Lithium manganese iron phosphate exhibits a higher voltage plateau compared to other lithium-containing transition metal phosphates, and its voltage difference to lithium-containing transition metal oxides is smaller. This facilitates the full utilization of the capacity per gram of the lithium-containing transition metal phosphate and thus further increases the volume energy density of the battery cell.

[0049] In any embodiment, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein, in the fully discharged state of the battery cell, the one-sided areal density of the negative electrode film layer is greater than or equal to 160 mg / 1540.25 mm² 2 is.

[0050] The negative electrode active material layer within the above-mentioned area shows that the negative electrode sheet has a higher loading with active substance, which has a positive effect on increasing the volume energy density of the battery cell.

[0051] In any embodiment, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein, in the fully discharged state of the battery cell, the one-sided areal density of the negative electrode film layer is 180 mg / 1540.25 mm² 2 up to 200 mg / 1540.25 mm 2 amounts.

[0052] In any embodiment, when the battery cell is completely discharged, the density of the negative electrode film layer is greater than or equal to 1.4 g / cm². 3 .

[0053] In any embodiment, the compaction density of the negative electrode film layer in the fully discharged state of the battery cell is 1.4 g / cm³. 3 up to 1.6 g / cm³ 3 .

[0054] A high compaction density contributes to increasing the loading of negative electrode active material on the negative electrode sheet; a low compaction density increases the porosity of the film layer and thereby improves the liquid retention properties. In the embodiments of the present application, the compaction density of the negative electrode film layer within the aforementioned range, when the battery cell is in a fully discharged state, facilitates the achievement of both a higher loading of active material and a suitable pore structure. This improves the liquid retention rate of the electrode sheet and reduces the polarization impedance, thereby improving the cycle performance and capacity utilization of the battery.

[0055] In any embodiment, the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises graphite.

[0056] In any embodiment, the negative electrode active material comprises one or more of natural flake graphite, artificial graphite, and microcrystalline graphite.

[0057] In any embodiment, the OI value of the orientation degree of the negative electrode active material is 1.3 to 5.5, where the OI value = I 004 / I 110 applies, where I 004 the integral surface of the diffraction peak of the 004 crystal plane in X-ray diffraction analysis is and I 110 the integral surface of the diffraction peak of the 110-crystal plane.

[0058] An excessively low OI value indicates poor orientation of the material and high internal disorder, which impairs structural stability. Conversely, an excessively high OI value signifies a highly ordered crystal arrangement, thereby reducing the material's porosity and thus diminishing its liquid retention capacity, which in turn increases the polarization impedance. In the embodiments of the present application, the OI value of the negative electrode active material within the aforementioned range facilitates a balance between structural stability and liquid retention capacity, thereby improving the cycle performance of the battery cell.

[0059] In any embodiment, the OI value of the orientation degree of the negative electrode active material is 2.5 to 4.

[0060] In the embodiments of the present application, the OI value of the negative electrode active material within the above-mentioned range contributes to further improving the structural stability and liquid retention capacity of the negative electrode active material, thereby improving the cycle performance of the battery cell.

[0061] In any embodiment, the volume particle size distribution D is V 50 of the negative electrode active material 16 µm to 22 µm.

[0062] In the embodiments of the present application, the D V 50% of the negative electrode active material within the above-mentioned area contributes to reducing the polarization impedance of the battery, thereby further improving the battery's cycle performance.

[0063] A second aspect of the present application provides a battery device comprising a battery cell provided in the first aspect of the present application.

[0064] A third aspect of the present application provides a power-consuming device comprising a battery device provided in the second aspect, wherein the battery device serves to provide electrical energy.

[0065] A fourth aspect of the present application provides an energy storage device comprising a battery device provided in the second aspect, wherein the battery device serves to store electrical energy. Brief description of the drawings

[0066] Unless otherwise indicated, in the drawings, the same reference numerals denote identical or similar components or elements in the different drawings. The drawings are not necessarily to scale. It should be understood that these drawings represent only some of the embodiments as disclosed in the present application and are not to be regarded as limiting the scope of protection of the present application. Fig. Figure 1 is a schematic representation of a positive electrode sheet according to an embodiment of the present application; Fig. Figure 2 is a schematic representation of a negative electrode sheet according to an embodiment of the present application; Fig. Figure 3 is a schematic representation of a power-consuming device according to some embodiments of the present application.

[0067] The drawings are not necessarily to scale. Detailed description of preferred embodiments

[0068] The following section describes in detail embodiments of a battery cell, a battery device, a power-consuming device, and an energy storage device specifically disclosed in the present application, possibly with reference to the drawings. However, an unnecessarily detailed description can be omitted. For example, a detailed description of known facts and a repeated description of essentially the same structure can be avoided. This is to prevent the following description from becoming unnecessarily long-winded, thus facilitating understanding by those skilled in the art. Furthermore, the drawings and the following description serve to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0069] The “range” disclosed in the present application is defined in terms of a lower bound and an upper bound. A given range is defined by selecting a lower bound and an upper bound. The selected lower bound and upper bound define the limits of the specific range. The ranges thus defined may or may not include the end values ​​and may be specified in any combination; that is, any lower bound can be combined with any upper bound to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, then ranges of 60 to 110 and 80 to 120 are also conceivable. Furthermore, if minimum range values ​​of 1 and 2 and maximum range values ​​of 3, 4, and 5 are listed, then all of the following ranges are conceivable: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5.In the present application, unless otherwise specified, a range of numbers "a to b" represents an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the range "0 to 5" means that all real numbers between "0 to 5" are listed therein, and "0 to 5" is simply an abbreviation for these number combinations. Furthermore, if a particular parameter is specified as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0070] Unless otherwise stated, all embodiments and optional embodiments of the present application may be combined to form new technical solutions, and such technical solutions should be considered to be contained in the disclosure of the present application.

[0071] Unless otherwise stated, all technical features and optional technical features of the present application can be combined to form new technical solutions, and such technical solutions should be considered to be contained in the disclosure of the present application.

[0072] Unless otherwise stated, all steps of the present application may be carried out sequentially or in any order, but preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) carried out sequentially, or that it may include steps (b) and (a) carried out sequentially. Similarly, when it is mentioned that the method may further include step (c), this means that step (c) may be added in any order. For example, the method may include steps (a), (b), and (c), or steps (a), (c), and (b), or steps (c), (a), and (b), etc.

[0073] Unless otherwise stated, the terms “comprise” and “contain” used in this application may be interpreted as either open or closed. For example, the terms “comprise” and “contain” may mean that they may also include or contain other, unlisted components, or that they may only include or contain the listed components.

[0074] Unless otherwise specified, the term "or" in this application means an inclusive "or". For example, the expression "A or B" means "A, B, or both A and B". More precisely, the condition "A or B" is satisfied if any of the following conditions are true: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0075] In the present application, the terms “several” and “different” refer to two or more.

[0076] Unless otherwise stated, the terms used in this application have the generally known meanings which are usually understood by the person skilled in the art.

[0077] Unless otherwise specified, the values ​​of the parameters mentioned in this application can be measured using various test methods commonly used in the art. For example, they can be measured according to the test methods specified in the embodiments of this application. Unless otherwise specified, the test temperature for each parameter is 25 °C.

[0078] The battery mentioned in the embodiments of the present application may refer to a single physical module comprising one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may comprise a battery cell, a battery module, or a battery pack, etc.

[0079] The battery cell is the smallest unit that makes up the battery and can independently perform charging and discharging functions.

[0080] If multiple battery cells are present, they are connected in series, parallel, or a mixed configuration via bus components. In some embodiments, the battery can be a battery module; if multiple battery cells are present, they are arranged and mounted to form a single battery module. In some embodiments, the battery can be a battery pack, the battery pack comprising a box body and battery cells, the battery cells or battery modules being housed within the box body. In some embodiments, the box body can be designed as part of a vehicle chassis. For example, part of the box body can become at least part of a floor panel of the vehicle, or part of the box body can become at least part of a cross member and a longitudinal member of the vehicle.

[0081] In some embodiments, the battery can serve as an energy storage device. Energy storage devices include energy storage containers, electrical energy storage cabinets, etc.

[0082] In some embodiments, the battery cells can be assembled into a battery module, where the number of battery cells contained in the module can be multiple. The exact number can be adjusted depending on the application and capacity of the battery module. Within the battery module, several battery cells can be arranged sequentially along its length. Of course, other arrangements are also possible. Furthermore, the multiple battery cells can be secured using fastening elements.

[0083] Optionally, the battery module can also include a housing with a receiving space, in which the multiple battery cells are received.

[0084] In some embodiments, the aforementioned battery modules can also be assembled into a battery pack. The number of battery modules contained in the battery pack can be adjusted depending on the application and the battery pack's capacity.

[0085] The battery pack can comprise a housing and multiple battery modules arranged within the housing. The housing comprises an upper and a lower housing; the upper housing covers the lower housing, forming an enclosed space to contain the battery modules. The multiple battery modules can be arranged within the housing in any configuration.

[0086] The battery provided by the embodiments of the present application may comprise a lithium-ion battery.

[0087] The battery cell comprises an electrode array. The electrode array typically includes a positive electrode sheet and a negative electrode sheet. The negative electrode sheet is the electrode where lithium ions are absorbed or lithiated during the charging process of the battery and where lithium is released or delithiated during the discharging process. The positive electrode sheet is the electrode where lithium ions are released or delithiated during the charging process of the battery and where lithium is absorbed or lithiated during the discharging process.

[0088] As the battery industry advances, the demands placed on battery cells are continuously increasing, and the standards for energy density in energy storage and traction batteries are rising year by year. The following technical approaches are commonly used in the state of the art to improve the energy density of battery cells: The use of stacked electrode arrangements increases the active material loading within the battery cell, resulting in a 5% to 8% improvement in space utilization compared to conventional wound structures. Furthermore, a pouch material is used for the battery cell casing, leading to weight reduction and contributing to improved volumetric energy density of the battery cell. However, studies show that pouch battery cells must be vacuum-sealed.During sealing, the casing material tends to develop stress concentrations at the corners of the electrode sheets, resulting in a larger gap between the electrode sheets at these locations compared to other areas. This imbalance in lithium ion transport pathways easily leads to lithium plating at the electrode sheet corners, significantly degrading the battery's cycle performance. Therefore, prior art often incorporates a chamfer at the edge of both the positive and negative electrode sheets. However, as the energy density requirements of the battery increase, so do the demands on the density and areal density of the battery's electrode sheets. The presence of chamfers at the edge of the positive electrode sheet increases the likelihood of burr formation, thus reducing product yield.Therefore, improving the energy density of the battery cell while ensuring cycle performance and processing yield has become an urgent technical challenge.

[0089] To address the aforementioned problems, a first aspect of the present application provides a battery cell comprising an electrode assembly and a housing body, wherein the electrode assembly is contained within the housing body and the housing body is made of a pouch material. The electrode assembly comprises a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are arranged stacked alternately. The negative electrode sheet comprises a negative electrode current collector, wherein, as shown in Fig.Figure 2 shows that the negative electrode current collector comprises a negative electrode current collector section 21, wherein the edge region of the negative electrode current collector section 21 is chamfered. As shown in Fig.As shown in Figure 1, the positive electrode sheet 1 comprises a positive electrode current collector 12, wherein the positive electrode current collector 12 comprises a positive electrode current collector section 121 and a positive electrode tab 122, which is arranged on a side of the positive electrode current collector section 121 extending along a first direction X, wherein the first direction X is perpendicular to the thickness direction Z of the battery cell.The positive electrode sheet 1 further comprises a positive electrode film layer 11, which is arranged on at least one side of the positive electrode current collection section 121 in the thickness direction Z of the battery cell, wherein the positive electrode film layer 11 comprises a positive electrode active material layer 111 as well as a first insulating layer 112 and a second insulating layer 113, which are arranged on the two opposite sides of the positive electrode active material layer 111 in the first direction X, wherein the first insulating layer 112 is arranged on a side of the positive electrode active material layer 111 that is adjacent to the positive electrode tab 122, and the second insulating layer 113 is arranged on a side of the positive electrode active material layer 111 that is away from the positive electrode tab 122.In the fully discharged state of the battery cell, the one-sided areal density of the positive electrode active material layer is 320 mg / 1540.25 mm. 2 .

[0090] In the prior art, the insulating layer is typically arranged only on the side of the electrode tab to mitigate the risk during electrode tab processing. In the embodiments of the present application, an insulating layer is also arranged on a side of the positive electrode active material layer that is away from the positive electrode tab. This reduces the influence of the stress concentration at the corners of the electrode tab on the distance between the positive electrode active material layers. Consequently, it is possible to reduce the risk of lithium plating in the battery without providing a chamfer on the positive electrode sheet, thereby ensuring both high processing yield and good cycle stability in the battery cell.

[0091] It should be noted that the first direction is perpendicular to the thickness direction of the battery cell. This first direction can be either the length or width direction of the battery cell and represents the direction in which the electrode tab extends. Fig. 1 serves only as an example illustration and does not mean that the first direction must necessarily be the direction of the long side.

[0092] The positive electrode active material layer within the aforementioned area indicates that the positive electrode sheet has a higher active material loading, which positively impacts the increase in the volume energy density of the battery cell. However, the applicant has found that chamfering the highly loaded positive electrode sheet to reduce the voltage concentration causes the positive electrode active material within the chamfered area to loosen or even detach under external force. This increases the likelihood of exposing the current collector of the positive electrode sheet, which negatively affects the battery's cycle performance. Therefore, in the embodiments of the present application, the positive electrode sheet is not chamfered.The positive electrode film layer comprises a positive electrode active material layer and insulating layers arranged on the two opposite sides of the positive electrode active material layer in the first direction. This configuration is particularly suitable for a battery cell with a high active material loading and enables a balance between high volume energy density, processing yield, and good cycle stability of the battery cell.

[0093] In the present application, the fully discharged state refers to the state achieved by placing the battery in an oven at a temperature of 25 °C and leaving it there for 2 hours until its temperature stabilizes at 25 °C, then discharging the battery with a constant current of 1 / 3 C to 2.5 V, followed by a 30-minute rest period, and then discharging it with a constant voltage of 2.5 V to 0.05 C.

[0094] In the present application, the term "the single-sided coating areal density of the positive electrode active material layer" has a meaning known in the art and can be tested using methods known in the art. As an example, a single-sided coated and cold-pressed positive electrode sheet is used (in the case of a double-sided coated positive electrode sheet, the positive electrode film layer can first be wiped off one side). This is punched out into small circular discs with an area S1, the weight of which is weighed and recorded as M1. Subsequently, the positive electrode film layer of the above-mentioned weighed positive electrode sheet is wiped off, and the weight of the current collector is weighed and recorded as M0. The single-sided areal density of the positive electrode film layer = (M1 - M0) / S1. To ensure the accuracy of the test results, several sets (e.g.,10 sets) of the samples to be tested are examined, and the average value is calculated as the test result.

[0095] In some embodiments, the one-sided areal density of the positive electrode active material layer in the fully discharged state of the battery cell can be 320 mg / 1540.25 mm². 2 , 320 mg / 1540.25 mm 2 , 325 mg / 1540.25 mm 2 , 330 mg / 1540.25 mm 2 , 335 mg / 1540.25 mm 2 , 340 mg / 1540.25 mm 2 , 345 mg / 1540.25 mm 2 , 350 mg / 1540.25 mm 2 , 355 mg / 1540.25 mm 2 , 360 mg / 1540.25 mm 2 , 365 mg / 1540.25 mm 2 , 370 mg / 1540.25 mm 2 , 375 mg / 1540.25 mm 2 , 380 mg / 1540.25 mm 2 , 385 mg / 1540.25 mm 2 , 390 mg / 1540.25 mm 2 , 395 mg / 1540.25 mm 2 , 400 mg / 1540.25 mm 2 , 405 mg / 1540.25 mm 2 , 410 mg / 1540.25 mm 2 , 415 mg / 1540.25 mm 2 or 420 mg / 1540.25 mm2 to be or to lie within a range of values ​​between any two of them.

[0096] In some embodiments and as in Fig. As shown in Figure 1, the dimension D1 of the first insulating layer 112 in the first direction X is 1 mm to 2.5 mm.

[0097] In the present application, the dimension D1 of the first insulating layer in the first direction refers to the dimension of the first insulating layer on the surface of the positive electrode current collecting section in the first direction, namely D1 in Fig. 1, which can be measured using methods and instruments known in engineering. For example, a high-precision micrometer (such as the Mitutoyo model 293-100 with an accuracy of 0.1 µm) can be used for measurement.

[0098] In some embodiments, the dimension D1 of the first insulating layer in the first direction can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm or 2.5 mm, or lie in a range of values ​​between any two of these.

[0099] The dimension D1 of the first insulating layer in the first direction is in the range of 1 mm to 2.5 mm. This effectively reduces the risk during the processing of the electrode tab and improves the processing yield of the battery. Furthermore, the first insulating layer contributes to the distribution of stresses at the corners, thus improving the cycle stability of the battery cell.

[0100] In some embodiments, the dimension D1 of the first insulating layer in the first direction is 1 mm to 2 mm.

[0101] A D1 thickness in the range of 1 mm to 2 mm contributes to further improving the processing yield and cycle life of the battery cell. At the same time, it helps to reduce the space required by the first insulating layer relative to the positive electrode active material layer, thereby increasing the volume energy density of the battery cell.

[0102] In some embodiments and as in Fig. As shown in Figure 1, the dimension D2 of the second insulating layer 113 in the first direction X is 1 mm to 4.5 mm.

[0103] In the present application, the dimension D2 of the second insulating layer in the first direction can be measured using methods and instruments known in the art. For example, a high-precision micrometer (such as the Mitutoyo model 293-100 with an accuracy of 0.1 µm) can be used for the measurement.

[0104] In some embodiments, the dimension D2 of the second insulating layer in the first direction is optionally 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm or 4.4 mm or 4.5 mm, or lies in a range of values ​​between any two of these.

[0105] The dimension D2 of the second insulating layer in the first direction, which lies between 1 mm and 4.5 mm, enables effective stress distribution from the casing to the positive electrode current collection section. This reduces the abnormal spacing changes caused by stress concentration at the corners and edges of the positive electrode sheet, thereby improving the cycle performance of the battery cell.

[0106] In some embodiments, the dimension D2 of the second insulating layer in the first direction is 2 mm to 3 mm.

[0107] A D2 thickness in the range of 2 mm to 3 mm contributes to further improving the cycle performance of the battery cell. At the same time, it helps to reduce the space required by the second insulating layer relative to the positive electrode active material layer, thereby increasing the volume energy density of the battery cell.

[0108] In some embodiments, the material of the first insulating layer and the material of the second insulating layer each independently comprise one or more of aluminium oxide, zirconium oxide and titanium oxide.

[0109] The material of the first insulating layer and the material of the second insulating layer comprise the aforementioned materials, which, on the one hand, help to reduce the stress concentration at the right-angled corners and edges of the electrode arrangement. On the other hand, as insulating materials, they help to reduce the likelihood of burrs created when chamfering the negative electrode sheet overlapping with the positive electrode sheet, thereby improving the cycle life and safety performance of the battery.

[0110] In some embodiments, the material of the first insulating layer and the material of the second insulating layer each comprise aluminium oxide.

[0111] In some embodiments, the chamfer includes an R-chamfer or a C-chamfer.

[0112] As in Fig.As shown in Figure 2, the R-chamfer is a rounded chamfer that achieves a smooth transition, resulting in a uniform stress distribution and reducing stress concentration points. However, this requires machining with a rounding tool of a specific radius, leading to higher tooling costs. Furthermore, tool changes for different radius roundings can increase production costs and times. The C-chamfer is a 45° chamfer angle, which removes identical dimensions from adjacent surfaces. This can be achieved with a standardized skew-angle tool or by adjusting the tool's feed angle. The tool offers greater versatility and is relatively less expensive, although its effectiveness in reducing stress concentrations is less pronounced than that of the R-chamfer.

[0113] In the embodiments of the present application, the chamfer of the negative electrode sheet comprises an R-chamfer or a C-chamfer. This enables a reduction in the voltage concentration at the right-angled corners and edges of the negative electrode sheet, thereby reducing the probability of lithium plating of the negative electrode sheet. This contributes to improving the cycle performance of the battery cell.

[0114] In some embodiments, the chamfer is an R-chamfer.

[0115] In the embodiments of the present application, the chamfer of the negative electrode sheet comprises an R-chamfer. This allows for a further reduction of the voltage concentration at the right-angled corners and edges of the negative electrode sheet, thereby reducing the probability of lithium plating of the negative electrode sheet. Consequently, this further improves the cycle performance of the battery cell.

[0116] In some embodiments, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction satisfies the condition 2 mm ≤ OH1 ≤ 6 mm.

[0117] In the present application, the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction can be measured using methods and instruments known in the art. For example, a high-precision micrometer can be used to measure the dimensions of the negative electrode film layer and the positive electrode active material layer in the first direction. The difference between the measured dimensions of the negative electrode film layer and the positive electrode active material layer constitutes OH1.

[0118] In some embodiments, the negative electrode sheet further comprises a negative electrode film layer, which is arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell. In the first direction, the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer can be 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm, 5.1 mm, 5.2 mm, 5.3 mm, 5.4 mm, 5.5 mm, 5.6 mm, 5.7 mm, 5.8 mm, 5.9 mm or 6 mm, or within a range of any two of these.

[0119] The dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction facilitates the provision of adequately sized space on the positive electrode sheet for the arrangement of the first and second insulating layers, thereby enabling a further improvement in the cycle performance of the battery cell. Simultaneously, the dimension of the negative electrode film layer is larger than that of the positive electrode film layer, which helps to provide sufficient lithium intercalation sites on the negative electrode sheet, thus reducing the likelihood of lithium plating of the negative electrode sheet and further improving the cycle performance of the battery cell. Furthermore, an excessively large OH1 can impair the loading of positive electrode active material.In the embodiments of the present application, OH1 facilitates the improvement of the cycle performance of the battery cell within the above-mentioned range while simultaneously ensuring the energy density.

[0120] In some embodiments, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction satisfies the condition 2 mm ≤ OH1 ≤ 5 mm.

[0121] In the embodiments of the present application, OH1 contributes within the above-mentioned range to further improving the cycle performance of the battery while simultaneously ensuring the energy density.

[0122] In some embodiments, the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer satisfies the condition OH1 - (D1 + D2) = 0 mm.

[0123] In the prior art, a technical solution for chamfering the positive electrode is typically used to reduce the stress concentration at the corners of the positive electrode sheet. However, this technical solution leads to the loss of some of the positive electrode active material, thereby reducing the volume energy density of the battery. In the embodiments of the present application, the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer satisfies the condition OH1 - (D1 + D2) = 0 mm, which means that the negative electrode film layer and the positive electrode film layer have the same dimensions. The dimensional difference between the negative electrode film layer and the positive electrode active material layer is used to form the first insulating layer and the second insulating layer.On the one hand, this structure helps to improve space utilization within the battery assembly and thus increase the energy density of the battery cell. On the other hand, the negative electrode current collector is chamfered, while the positive electrode current collector is not. The negative electrode film layer has the same dimensions as the positive electrode film layer. This allows the first and second insulating layers in the positive electrode film layer to effectively distribute the stresses generated by the contraction of the casing. This reduces the stress concentration at the edges of the negative electrode sheet and thus further improves the cycle performance of the battery cell.

[0124] In some embodiments, the dimensional difference OH2 between the negative electrode film layer and the positive electrode active material layer in the second direction satisfies the condition 1 mm ≤ OH2 ≤ 3 mm, where any two of the first direction, the second direction and the thickness direction of the battery cell are perpendicular to each other.

[0125] In the present application, the dimensions of the negative electrode film layer in the second direction and the dimensions of the positive electrode active material layer in the second direction can be measured using methods and instruments known in the art. For example, a high-precision micrometer (such as the Mitutoyo model 293-100 with an accuracy of 0.1 µm) can be used for the measurement.

[0126] In the present application, any two directions of the first direction, the second direction, and the thickness direction of the battery cell are perpendicular to each other. The first direction can be the longitudinal direction of the battery cell or the thickness direction of the battery cell. If, as in Fig. As shown in Figure 1, the first direction X is the longitudinal direction of the battery cell, and the second direction Y is the lateral direction of the battery cell. If the first direction is the lateral direction of the battery cell, the second direction is the longitudinal direction of the battery cell.

[0127] In some embodiments, the dimensional difference OH2 between the negative electrode film layer and the positive electrode active material layer in the second direction can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3 mm, or lie in a range of values ​​between any two of these.

[0128] In the embodiments of the present application, maintaining the dimensional difference OH2 between the negative electrode film layer and the positive electrode active material layer within the aforementioned range facilitates the provision of sufficient lithium intercalation sites on the negative electrode sheet. This helps to reduce the probability of lithium plating of the negative electrode sheet and thereby improve the cycle performance of the battery cell. [Positive electrode sheet]

[0129] In some embodiments, the areal density of the positive electrode active material layer on one side is 320 mg / 1540.25 mm² when the battery cell is fully discharged. 2 up to 400 mg / 1540.25 mm 2 .

[0130] In some embodiments, when the battery cell is completely discharged, the density of the positive electrode active material layer is greater than or equal to 2.3 g / cm³. 3 .

[0131] In the present application, the compaction density of the positive electrode active material layer can be measured using methods and instruments known in the art. As an example, the battery is placed in an oven at a temperature of 25 °C and left to stand for 2 hours until its temperature stabilizes at 25 °C. The battery is discharged at a constant current of 1 / 3 C to 2.5 V and then left to stand for 30 minutes. Subsequently, the battery is discharged at a constant voltage of 2.5 V to 0.05 C. The battery is disassembled to obtain the positive electrode sheet. The remaining electrolyte solution is treated with dimethyl carbonate solvent, the electrode sheet is dried, and cut into small circular discs with an area S (in cm²). 2The positive electrode sheet is cut. Its mass is determined as W1 (in g), and its thickness T1 (in cm) is measured with a high-precision micrometer. The positive electrode film layer of the weighed electrode sheet is then wiped. The mass of the current collector is weighed and designated as W2 (in g). The thickness of the current collector is measured with a high-precision micrometer and designated as T2. The compaction density PD of the positive electrode film layer is calculated as follows: PD = (W1 - W2) / [(T1 - T2) × S], where PD is in g / cm². 3 is expressed.

[0132] In some embodiments, the compaction density of the positive electrode film layer, when the battery cell is in a fully discharged state, can be 2.3 g / cm³. 3 , 2.31 g / cm³ 3 , 2.32 g / cm³ 3 , 2.33 g / cm³ 3 , 2.34 g / cm³ 3 , 2.35 g / cm³ 3 , 2.36 g / cm³ 3 , 2.37 g / cm³ 3 , 2.38 g / cm³3 , 2.39 g / cm 3 , 2.40 g / cm 3 , 2.41 g / cm 3 , 2.42 g / cm 3 , 2.43 g / cm 3 , 2.44 g / cm 3 , 2.45 g / cm 3 , 2.46 g / cm 3 , 2.47 g / cm 3 , 2.48 g / cm 3 , 2.49 g / cm 3 , 2.5 g / cm 3 , 2.51 g / cm 3 , 2.52 g / cm 3 , 2.53 g / cm 3 , 2.54 g / cm 3 , 2.55 g / cm 3 , 2.56 g / cm 3 , 2.57 g / cm 3 , 2.58 g / cm 3 , 2.59 g / cm 3 , 2.6 g / cm 3 , 2.61 g / cm 3 , 2.62 g / cm 3 , 2.63 g / cm 3 , 2.64 g / cm 3 oder 2.65 g / cm 3 betragen oder in einem Wertbereich zwischen beliebigen zwei davon liegen.

[0133] A high compaction density contributes to increasing the loading of positive electrode active material on the positive electrode sheet; a low compaction density increases the porosity of the film layer and thereby improves the liquid retention properties. In the embodiments of the present application, the compaction density of the positive electrode film layer within the aforementioned range, when the battery cell is in a fully discharged state, facilitates the achievement of both a higher loading of active material and a suitable pore structure. This improves the liquid retention rate of the electrode sheet and reduces the polarization impedance, thereby improving the cycle performance and capacity utilization of the battery.

[0134] In some embodiments, the compaction density of the positive electrode film layer in the fully discharged state of the battery cell is 2.3 g / cm³.3 up to 2.6 g / cm³ 3 .

[0135] In some embodiments, the positive electrode active material layer comprises a positive electrode active material, wherein the positive electrode active material comprises a lithium-containing transition metal oxide particle and a lithium-containing transition metal phosphate particle.

[0136] Lithium-containing transition metal oxides have a higher capacity per gram. In the embodiments of the present application, the positive electrode active material comprises a lithium-containing transition metal oxide, which contributes to improving the energy density of the battery cell. Lithium-containing transition metal phosphates exhibit good cycle performance. In the embodiments of the present application, the positive electrode active material comprises a lithium-containing transition metal phosphate, which contributes to improving the cycle performance of the battery cell.

[0137] In some embodiments, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles is 5:5 to 9:1.

[0138] In some embodiments, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles can be 5:5, 5.5:4.5, 6:4, 6.5:3.5, 7:3, 7.5:2.5, 8:2, 8.5:1.5 or 9:1, or lie in a ratio range between any two of these.

[0139] In the embodiments of the present application, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles within the above-mentioned range contributes to ensuring the cycle performance of the battery cell and the energy density.

[0140] In some embodiments, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles is 6:4 to 8:2.

[0141] In the embodiments of the present application, the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles within the above-mentioned range contributes to further improving the cycle performance of the battery cell while simultaneously ensuring the energy density.

[0142] In some embodiments, the lithium-containing transition metal oxide particle comprises a component represented by the following general formula: Li a1 Ni x1 Co y1 M1 z1 M2 w1 O 2-b1 Formula 1 where M1 includes one or more of Mn and Al, M2 includes one or more of Zr, B, Mg, Ti, W, Mo, Nb, Ta, Sr, Sb and K, where 0.8 ≤ a1 ≤ 1.2, 0 ≤ x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ z1 ≤ 1, 0 ≤ w1 ≤ 0.1, -0.1 ≤ b1 ≤ 0.1.

[0143] In some embodiments, a1 is optionally 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15 or 1.2 or lies in any range between any two of them.

[0144] In some embodiments, x1 is optionally 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or 1.0 or lies in any range between any two of these.

[0145] In some embodiments, y1 is optionally 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or 1.0 or lies in any range between any two of them.

[0146] In some embodiments, z1 is optionally 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or 1.0 or lies in any range between any two of them.

[0147] In some embodiments, w1 is optionally 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 or 0.1 or lies in any range between any two of these.

[0148] In some embodiments, b1 is optionally -0.1, -0.05, 0, 0.05 or 0.1, or lies in any range between any two of these.

[0149] If the positive electrode active material layer includes lithium-containing transition metal oxides of the types mentioned above, the capacity per gram of the positive electrode active material can be further increased, thereby further improving the energy density of the battery cell.

[0150] In some embodiments, the lithium-containing transition metal phosphate particle comprises a component represented by the following general formula: Li x A y Me a M b P 1-c X c Y z Formula II where 0.1 ≤ x ≤ 1.3, 0 ≤ y ≤ 1.3 and 0.8 ≤ x + y ≤ 1.3; 0.9 ≤ a ≤ 1.5, 0 ≤ b ≤ 0.5 and 0.9 ≤ a + b ≤ 1.5; 0 ≤ c ≤ 0.5; 3 ≤ z ≤ 5; A includes one or more of Na, K and Mg; Me includes one or more of Mn, Fe, Co and Ni; M includes one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La and Ce; X comprises one or more of S, Si, Cl, B, C and N; and Y comprises one or more of O and F.

[0151] In some embodiments, x is optionally 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2 or 1.3 or lies in any range between any two of these.

[0152] In some embodiments, y is optionally 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2 or 1.3 or lies in any range between any two of them.

[0153] In some embodiments, x + y is optionally 0.8, 0.9, 0.95, 1.0, 1.1, 1.2 or 1.3, or lies in any range between any two of these.

[0154] In some embodiments, a is optionally 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.3, 1.4 or 1.5, or lies in any range between any two of them.

[0155] In some embodiments, b is optionally 0, 0.01, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5, or lies in any range between any two of them.

[0156] In some embodiments, a + b is optionally 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.3, 1.4 or 1.5, or lies in any range between any two of them.

[0157] In some embodiments, c is optionally 0, 0.01, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5, or lies in any range between any two of them.

[0158] In some embodiments, z is optionally 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 or 5, or lies in any range between any two of them.

[0159] The lithium-containing transition metal phosphate, which comprises the component represented by the general formula above, exhibits good thermal and cycle stability, thereby contributing to improved safety and cycle performance of the battery.

[0160] In some embodiments, the lithium-containing transition metal phosphate particle comprises one or more of lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate fluoride, lithium manganese iron phosphate, lithium iron phosphate fluoride, lithium manganese iron phosphate fluoride and modified materials thereof.

[0161] In some embodiments, the lithium-containing transition metal phosphate comprises one or more lithium manganese iron phosphate and its modified materials.

[0162] Lithium manganese iron phosphate exhibits a higher voltage plateau compared to other lithium-containing transition metal phosphates, and its voltage difference to lithium-containing transition metal oxides is smaller. This facilitates the full utilization of the capacity per gram of the lithium-containing transition metal phosphate and thus further increases the volume energy density of the battery cell.

[0163] In some embodiments, the positive electrode current collector can be a metal foil or a composite current collector. For example, aluminum foil can be used as the metal foil. The composite current collector can comprise a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) on the polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0164] In some embodiments, the positive electrode film layer optionally comprises a binder. For example, the binder may comprise at least one of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylic resin.

[0165] In some embodiments, the positive electrode film layer optionally further comprises a conductive material. For example, the conductive material may comprise at least one of superconducting carbon, carbon black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. [Negative electrode sheet]

[0166] In some embodiments, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein, in the fully discharged state of the battery cell, the one-sided areal density of the negative electrode film layer is greater than or equal to 160 mg / 1540.25 mm² 2 is.

[0167] In the present application, the one-sided areal density of the negative electrode film layer can be measured using methods and instruments known in the art. As an example, the test can be carried out with reference to the test method for the one-sided areal density of the positive electrode active material layer.

[0168] In some embodiments, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell. In the fully discharged state of the battery cell, the one-sided areal density of the negative electrode film layer can be 160 mg / 1540.25 mm². 2 , 165 mg / 1540.25 mm 2 , 170 mg / 1540.25 mm 2 , 175 mg / 1540.25 mm 2 , 180 mg / 1540.25 mm 2 , 185 mg / 1540.25 mm 2 , 190 mg / 1540.25 mm 2 , 195 mg / 1540.25 mm 2 , 200 mg / 1540.25 mm 2 , 205 mg / 1540.25 mm 2 , 210 mg / 1540.25 mm 2 , 215 mg / 1540.25 mm 2 or 220 mg / 1540.25 mm 2 to be or to lie within a range of values ​​between any two of them.

[0169] The negative electrode active material layer within the above-mentioned area shows that the negative electrode sheet has a higher loading with active substance, which has a positive effect on increasing the volume energy density of the battery cell.

[0170] In some embodiments, the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein, in the fully discharged state of the battery cell, the one-sided areal density of the negative electrode film layer is 180 mg / 1540.25 mm² 2 up to 200 mg / 1540.25 mm 2 amounts.

[0171] In some embodiments, when the battery cell is completely discharged, the density of the negative electrode film layer is greater than or equal to 1.4 g / cm². 3 .

[0172] In the present application, the compaction density of the negative electrode film layer can be measured using methods and instruments known in the art. As an example, the test can be carried out with reference to the test method for the compaction density of the positive electrode active material layer.

[0173] In some embodiments, the compaction density of the negative electrode film layer in the fully discharged state of the battery cell can be 1.4 g / cm³. 3 , 1.41 g / cm³ 3 , 1.42 g / cm³ 3 , 1.43 g / cm³ 3 , 1.44 g / cm³ 3 , 1.45 g / cm³ 3 , 1.46 g / cm³ 3 , 1.47 g / cm³ 3 , 1.48 g / cm³ 3 , 1.49 g / cm³ 3 , 1.50 g / cm² 3 , 1.51 g / cm³ 3 , 1.52 g / cm³ 3 , 1.53 g / cm³ 3 , 1.54 g / cm³ 3 , 1.55 g / cm³ 3 , 1.56 g / cm³ 3 , 1.57 g / cm³ 3 , 1.58 g / cm³ 3 , 1.59 g / cm³ 3 , 1.60 g / cm³3 , 1.61 g / cm³ 3 , 1.62 g / cm³ 3 , 1.63 g / cm³ 3 , 1.64 g / cm³ 3 or 1.65 g / cm² 3 to be or to lie within a range of values ​​between any two of them.

[0174] In some embodiments, the compaction density of the negative electrode film layer in the fully discharged state of the battery cell is 1.4 g / cm³. 3 up to 1.6 g / cm³ 3 .

[0175] A high compaction density contributes to increasing the loading of negative electrode active material on the negative electrode sheet; a low compaction density increases the porosity of the film layer and thereby improves the liquid retention properties. In the embodiments of the present application, the compaction density of the negative electrode film layer within the aforementioned range, when the battery cell is in a fully discharged state, facilitates the achievement of both a higher loading of active material and a suitable pore structure. This improves the liquid retention rate of the electrode sheet and reduces the polarization impedance, thereby improving the cycle performance and capacity utilization of the battery.

[0176] In some embodiments, the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises graphite.

[0177] In some embodiments, the negative electrode active material comprises one or more of natural flake graphite, artificial graphite, and microcrystalline graphite.

[0178] In some embodiments, the negative electrode active material comprises synthetic graphite.

[0179] In some embodiments, the OI value of the orientation degree of the negative electrode active material is 1.3 to 5.5, where the OI value = I 004 / I 110 applies, where I 004 the integral surface of the diffraction peak of the 004 crystal plane in X-ray diffraction analysis is and I 110 the integral surface of the diffraction peak of the 110-crystal plane.

[0180] The OI value, or orientation degree, has a well-known meaning in engineering and represents the degree of order in the arrangement of crystals or particles within a material.

[0181] In the present application, the orientation index (OI) of the negative electrode active material can be measured using methods and instruments known in the art. As an example, testing can be carried out with an X-ray diffractometer (such as the Bruker D8 Discover) in accordance with JISK 0131-1996 and JB / T 4220-2011. This yields the X-ray diffraction pattern of the material, from which the OI can be determined using the formula OI = I 004 / I 110 is calculated. 004 is the integral surface of the diffraction peak corresponding to the 004 crystal plane of crystalline carbon in the material, and I 110is the integral surface of the diffraction peak corresponding to the 110 crystal plane of crystalline carbon in the material. In the X-ray diffraction analysis of the present application, a copper target can be used as the anode target, with CuKα radiation being used as the source. The radiation wavelength is 2 = 1.5418 Å, with a 2θ-angle scan range of 20° to 80° and a scan rate of 4° / min.

[0182] In some embodiments, the OI value of the orientation degree of the negative electrode active material is optionally 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4 or 5.5, or lies within a range of any two of that.

[0183] An excessively low OI value indicates poor orientation of the material and high internal disorder, which impairs structural stability. Conversely, an excessively high OI value signifies a highly ordered crystal arrangement, thereby reducing the material's porosity and thus diminishing its liquid retention capacity, which in turn increases the polarization impedance. In the embodiments of the present application, the OI value of the negative electrode active material within the aforementioned range facilitates a balance between structural stability and liquid retention capacity, thereby improving the cycle performance of the battery cell.

[0184] In some embodiments, the OI value of the orientation degree of the negative electrode active material is 2.5 to 4.

[0185] In the embodiments of the present application, the OI value of the negative electrode active material within the above-mentioned range contributes to further improving the structural stability and liquid retention capacity of the negative electrode active material, thereby improving the cycle performance of the battery cell.

[0186] In some embodiments, the volume particle size distribution D V 50 of the negative electrode active material 16 µm to 22 µm.

[0187] In the present application, the term “volume particle size distribution D” VThe term "50" has a well-known meaning in engineering. It denotes the particle size at which the cumulative volume distribution percentage of the material reaches 50%. The test can be performed using methods and instruments known in engineering. For example, according to GB / T 19077-2016 "Particle size distribution - Laser diffraction method", a convenient determination can be carried out using a laser particle size analyzer. The testing instrument could be the Mastersizer 3000 laser particle size analyzer from Malvern Instruments Ltd., UK.

[0188] In some embodiments, the volume particle size distribution D V 50 of the negative electrode active material are 16 µm, 16.5 µm, 17 µm, 17.5 µm, 18 µm, 18.5 µm, 19 µm, 19.5 µm, 20 µm, 20.5 µm, 21 µm, 21.5 µm or 22 µm or are in a range between any two of them.

[0189] In the embodiments of the present application, the D V50% of the negative electrode active material within the above-mentioned area contributes to reducing the polarization impedance of the battery, thereby further improving the battery's cycle performance.

[0190] In some embodiments, the negative electrode current collector can be a metal foil or a composite current collector. For example, copper foil can be used as the metal foil. The composite current collector can comprise a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) on the polymer material substrate (such as polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0191] In some embodiments, the negative electrode film layer optionally comprises a binder. The binder can be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0192] In some embodiments, the negative electrode film layer optionally comprises a conductive material. The conductive material can be selected from at least one of superconducting carbon, carbon black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0193] In some embodiments, the negative electrode film layer optionally also includes other auxiliary materials, such as a thickening agent (such as sodium carboxymethylcellulose (CMC-Na)). [Separator]

[0194] In some embodiments, the battery cell also includes a separator.

[0195] The present application does not impose any special restrictions on the type of separator, and any known separator with good chemical and mechanical stability and a porous structure may be used.

[0196] In some embodiments, the separator material can be selected from at least one of glass fiber, nonwoven fabric, 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 separator is a multi-layer composite film, the materials of each layer can be the same or different without any particular restriction. [Electrolyte]

[0197] In some embodiments, the battery cell also includes an electrolyte.

[0198] The electrolyte serves to conduct ions between the positive and negative electrode sheets. This application does not impose any specific restrictions regarding the type of electrolyte, and the type can be selected according to the requirements. For example, the electrolyte can be liquid, gel-like, or completely solid.

[0199] In some embodiments, the electrolyte is in the form of an electrolyte solution. The electrolyte solution comprises an electrolyte salt and a solvent.

[0200] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluorobisoxalatophosphate and lithium tetrafluoro(oxalato)phosphate.

[0201] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone.

[0202] In some embodiments, the electrolyte solution optionally includes an additive. For example, the additive may include a negative electrode film-forming additive, a positive electrode film-forming additive, and an additive that can improve certain battery performance characteristics, such as an additive that improves the battery's overcharge behavior, an additive that improves the battery's high-temperature performance, and an additive that improves the battery's low-temperature performance. Battery device

[0203] The embodiments of the present application further provide a battery device, wherein the battery device comprises a battery cell provided by the embodiments of the present application.

[0204] The battery device comprises one or more battery modules, battery packs, or energy storage batteries. Power-consuming device

[0205] The embodiments of the present application further provide a power-consuming device, wherein the power-consuming device comprises a battery device provided by the embodiments of the present application, the battery device serving to provide electrical energy. The battery can be used as the power source of the power-consuming device. The power-consuming device can be, but is not limited to, a mobile device (such as a mobile phone, laptop, etc.), an electric vehicle (such as a pure electric vehicle, hybrid electric vehicle, plug-in hybrid electric vehicle, electric bicycle, electric scooter, electric golf cart, electric truck, etc.), an electric train, a ship, a satellite, etc.

[0206] The power-consuming device can select the specific battery type according to its operating requirements, e.g., a battery cell, a battery module, or a battery pack. Energy storage device

[0207] The embodiments of the present application provide an energy storage device comprising a battery device provided by the embodiments of the present application, wherein the battery device serves to store electrical energy. The battery device can serve as the energy storage unit of the energy storage device. Energy storage units can be, among other things, energy storage containers, energy storage cabinets, energy storage power plants, energy storage battery packs, or portable energy storage systems.

[0208] Fig.Figure 3 shows a schematic representation of a power-consuming device as an example. The power-consuming device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the power-consuming device's requirements for high power and high energy density, a battery pack or battery module can be used.

[0209] Another example of a power-consuming device could be a mobile phone, a tablet, a laptop, etc. The power-consuming device typically needs to be lightweight and thin, and a battery cell can be used as its power source. Example of implementation

[0210] The following are exemplary embodiments of the present application. These embodiments are for illustrative purposes only and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the technical literature or product instructions must be followed. All reagents and instruments used without manufacturer information are commercially available products. I. Manufacturing Method Example 1(1) Production of the positive electrode sheet

[0211] Production of the paste for the positive electrode active material layer: LiNi 0,92 Co 0,04 Mn 0,04 O2, LiMn 0,3 Fe 0,7PO4, conductive carbon black, and the binder PVDF were mixed in a mass ratio of 68.6:29.4:1:1. The solvent NMP was added and stirred under vacuum until the system was homogeneous, thus obtaining the paste of the positive electrode film layer.

[0212] The paste of the positive electrode active material layer was used to uniformly coat both sides of a 13 µm thick aluminum foil. After air drying at room temperature, the foil was placed in an oven for further drying and then cold-pressed to obtain the positive electrode sheet. The compaction density of the positive electrode film layer was 2.55 g / cm³. 3 .

[0213] Preparation of the insulating layer paste: Ceramic particles Al₂O₃ (sourced from Keliansheng New Materials Co., Ltd., model L30), polyvinylidene fluoride (PVDF), and the dispersant ammonium polyacrylate were mixed in a mass ratio of 62:25:3. The solvent NMP was added and stirred in a vacuum mixing vessel until a uniform consistency was achieved, resulting in an insulating ceramic paste. This was then applied to both sides of the electrode sheet along with the positive electrode film layer.

[0214] The positive electrode tab was obtained by laser cutting the aluminum foil. (2) Production of the negative electrode sheet

[0215] Preparation of the negative electrode film paste: The negative electrode active material made of synthetic graphite, the binder polyvinyl alcohol, and the conductive agent SP-Li were thoroughly milled in a ball mill in a solvent system of deionized water in a mass ratio of 90:5:5 to obtain the negative electrode paste. The OI value of the negative electrode active material made of synthetic graphite was 3 and D V The 50 value was 19.5 µm.

[0216] The paste for the negative electrode film layer was used to uniformly coat both sides of an 8 µm thick copper foil. After vacuum drying overnight at 110 °C, the negative electrode sheet was cold-pressed to a density of 1.6 g / cm³. 3The negative electrode tab was then produced by laser cutting the copper foil. The electrode sheet was then punched and chamfered as follows: The four corners of the negative electrode current collector were cut off to create an R-chamfer with a radius of 1.5% of the width of the negative electrode current collector section. The chamfered electrode sheet was then trimmed to form the negative electrode sheet. (3) Separator

[0217] The porous aluminum oxide was added to the solvent NMP (N-methyl-2-pyrrolidone), thoroughly stirred, sprayed onto both sides of the polyethylene base film, and then dried. PVDF was dissolved in the solvent NMP (N-methyl-2-pyrrolidone). After thorough stirring, the solution was sprayed onto both surfaces of the porous aluminum oxide layer facing away from the base film. After drying, a separator with a bonding layer exhibiting a porous, continuous morphology was obtained.

[0218] The polyethylene base film has a thickness of 11 µm, the layer of porous aluminium oxide has a thickness of 1.5 µm on one side and the PVDF layer has a thickness of 0.5 µm on one side. (4) Electrolyte solution

[0219] Lithium hexafluorophosphate (LiPF6) and lithium bis(fluorosulfonyl)imide (LiFSI) were dissolved in ethylene carbonate (EC), diethyl carbonate (DEC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1 to form a homogeneous solution. This yielded an electrolyte solution with a LiPF6 concentration of 0.7 mol / L and a LiFSI concentration of 0.3 mol / L. (5) Battery production

[0220] The positive and negative electrode sheets obtained by cutting were stacked using the Z-stacking method. The stacking sequence is "positive electrode sheet - separator - negative electrode sheet - separator," thus forming the electrode assembly. The baked electrode assembly was then placed in an aluminum-plastic foil, filled with electrolyte, vacuum-sealed, and thermally sealed to create an airtight seal. This process ultimately resulted in the stacked pouch battery cell.

[0221] In embodiment 1, the areal density of the positive electrode active material layer on one side of the fully discharged battery cell was 330 mg / 1540.25 mm². 2 and the one-sided coating area density of the negative electrode film layer 185 mg / 1540.25 mm² 2The length of the positive electrode current collection section was 545 mm and its width 118 mm; the length of the negative electrode current collection section was 545 mm and its width 119.5 mm; the dimension of the positive electrode active material layer was 541 mm in the longitudinal direction of the battery cell and 118 mm in the lateral direction of the battery cell; the dimension of the negative electrode film layer was 545 mm in the longitudinal direction of the battery cell and 119.5 mm in the lateral direction of the battery cell; in the longitudinal direction of the battery cell, the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer was 4 mm; in the lateral direction of the battery cell, the dimensional difference OH2 between the negative electrode film layer and the positive electrode active material layer was 1.5 mm;The first insulating layer and the second insulating layer were arranged longitudinally on the two opposite sides of the positive electrode active material layer of the battery cell; in the longitudinal direction of the battery cell, dimension D1 of the first insulating layer was 1.5 mm, while dimension D2 of the second insulating layer was 2.5 mm. Example 2

[0222] The manufacturing process of embodiment 2 was essentially identical to that of embodiment 1, with the difference that the dimension D2 of the second insulating layer in the longitudinal direction of the battery cell was reduced by 0.5 mm, i.e., D2 was adjusted to 2 mm. At the same time, the dimension of the positive electrode active material layer in the longitudinal direction of the battery cell was increased by 0.5 mm. Example 3

[0223] The manufacturing process of embodiment 3 was essentially identical to that of embodiment 1, with the difference that the dimension D2 of the second insulating layer in the longitudinal direction of the battery cell was increased by 1 mm, i.e., D2 was adjusted to 3.5 mm. At the same time, the dimension of the positive electrode active material layer in the longitudinal direction of the battery cell was decreased by 1 mm. Example 4

[0224] The manufacturing process of embodiment 4 was essentially identical to that of embodiment 1, with the difference that the dimension D2 of the second insulating layer in the longitudinal direction of the battery cell was reduced by 1.5 mm, i.e., D2 was adjusted to 1 mm. At the same time, the dimension of the positive electrode active material layer in the longitudinal direction of the battery cell was increased by 1.5 mm. Example 5

[0225] The manufacturing process of embodiment 5 was essentially identical to that of embodiment 1, with the difference that the dimension D2 of the second insulating layer in the longitudinal direction of the battery cell was increased by 2 mm, i.e., D2 was adjusted to 4.5 mm. At the same time, the dimension of the positive electrode active material layer in the longitudinal direction of the battery cell was decreased by 2 mm. Example 6

[0226] The manufacturing process of embodiment 6 was essentially identical to that of embodiment 1, with the difference that the dimension D1 of the first insulating layer in the longitudinal direction of the battery cell was increased by 1 mm, i.e., D1 was adjusted to 2.5 mm. At the same time, the dimension of the positive electrode active material layer in the longitudinal direction of the battery cell was decreased by 1 mm. Example 7

[0227] The manufacturing process of embodiment 7 was essentially identical to that of embodiment 1, with the difference that the dimension D1 of the first insulating layer in the longitudinal direction of the battery cell was reduced by 0.5 mm, i.e., D1 was adjusted to 1 mm. At the same time, the dimension of the positive electrode active material layer in the longitudinal direction of the battery cell was increased by 0.5 mm. Example 8

[0228] The manufacturing process of embodiment 8 was essentially identical to that of embodiment 1, with the difference that artificial graphite with an OI value of orientation grade 1.3 was selected as the negative electrode active material. Example 9

[0229] The manufacturing process of embodiment 9 was essentially identical to that of embodiment 1, with the difference that artificial graphite with an OI value of orientation grade 5.5 was selected as the negative electrode active material. Example 10

[0230] The manufacturing process of embodiment 10 was essentially identical to that of embodiment 1, with the difference that the D V The 50 value of the negative electrode active material was 26 µm. Example 11

[0231] The manufacturing process of embodiment 11 was essentially identical to that of embodiment 1, with the difference that the D V The 50 value of the negative electrode active material was 11 µm. Example 12

[0232] The manufacturing process of embodiment 12 was essentially identical to that of embodiment 1, with the difference that the mass ratio of LiNi was used in the production of the paste of the positive electrode active material layer. 0,92 Co 0,04 Mn 0,04 O2, LiMn 0,3 Fe 0,7 PO4, the conductive carbon black and the binder PVDF were adjusted to 49:49:1:1. Example 13

[0233] The manufacturing process of embodiment 13 was essentially identical to that of embodiment 1, with the difference that the mass ratio of LiNi was used in the production of the paste of the positive electrode active material layer. 0,92 Co 0,04 Mn 0,04 O2, LiMn 0,3 Fe 0,7 PO4, the conductive carbon black and the binder PVDF were adjusted to 88.2:9.8:1:1. Example 14

[0234] The manufacturing process of embodiment 14 was essentially identical to that of embodiment 1, with the difference that the coating weight for the paste of the positive electrode active material layer and the paste of the negative electrode film layer was adjusted during the coating process. As a result, in the fully discharged state of the manufactured battery, the areal density of the positive electrode film layer on one side was 400 mg / 1540.25 mm². 2 and the one-sided areal density of the negative electrode film layer 215 mg / 1540.25 mm² 2 . Comparative example 4

[0235] The manufacturing process of comparative example 4 was essentially identical to that of embodiment 1, with the difference that the coating weight for the paste of the positive electrode active material layer and the paste of the negative electrode film layer was adjusted during coating. As a result, in the fully discharged state of the manufactured battery, the areal density of the positive electrode film layer on one side was 300 mg / 1540.25 mm². 2 and the one-sided areal density of the negative electrode film layer 160 mg / 1540.25 mm² 2 . Comparative example 1

[0236] The manufacturing process of comparative example 1 was essentially identical to that of comparative example 4, with the difference that no second insulating layer was provided. At the same time, the dimension of the positive electrode active material layer in the longitudinal direction of the battery cell was increased by 2.5 mm. Comparative example 2

[0237] The manufacturing process of Comparative Example 2 was essentially identical to that of Comparative Example 4, with the difference that the dimension of the positive electrode current collector section in the longitudinal direction of the battery was 542.5 mm and no second insulating layer was provided. An R-chamfer was applied to each of the four corners of the positive electrode current collector section, with the chamfer radius being 1.5% of the width of the positive electrode current collector section. Comparative example 3

[0238] The manufacturing process of Comparative Example 3 was essentially identical to that of Comparative Example 1, with the difference that the coating weight for the paste of the positive electrode active material layer and the paste of the negative electrode film layer was adjusted during the coating process. As a result, in the fully discharged state of the manufactured battery, the areal density of the positive electrode film layer on one side was 330 mg / 1540.25 mm². 2 and the one-sided areal density of the negative electrode film layer 185 mg / 1540.25 mm² 2 . II. Performance Tests 1. Cyclic Capacity Retention Rate

[0239] At 25 °C, the battery was charged to 4.25 V of its nominal capacity at a rate of 0.33 C. It was then charged to 0.05 C at a constant voltage of 4.25 V. After a 10-minute rest period, it was discharged to 2.5 V at a rate of 1 C, followed by another 10-minute rest period. This constituted one charge and discharge cycle. The discharge capacity of the battery cell at this point was recorded as the discharge capacity E1 of the first battery cycle. This charge and discharge cycle was repeated 1000 times, and the discharge capacity of the battery cell at this point was recorded as E2. Cyclic capacity retention rate after 1000 cycles = E2 / E1 × 100%. 2. Volume energy density

[0240] The battery was left to rest for 2 hours at 25 °C to ensure its temperature was 25 °C. At 25 °C, the battery was charged at 0.33 C to the final charging voltage of 4.25 V and continued charging at constant voltage until the current reached 0.05 C, at which point charging was terminated (where C represented the battery's nominal capacity). The battery was then left to rest for 1 hour at 25 °C and subsequently discharged at 0.33 C to the final discharge voltage of 2.5 V at 25 °C. The total discharge energy of the battery was recorded as E0. The battery's length, width, and height were measured, and its volume V0 = length × width × height was calculated. The volumetric energy density of the battery = discharge energy E0 / battery volume V0, expressed in Wh / L. III. Test results

[0241] The test results of the above-mentioned embodiments and comparison examples are shown in Tables 1 to 7. Table 1 Dimension D1 (mm) of the first insulating layer in the first direction Dimension D2 (mm) of the second insulating layer in the first direction Dimensional difference OH1 (mm) between the negative electrode film layer and the positive electrode active material layer in the first direction Mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles One-sided surface density (mg / 1540.25 mm²) 2 ) the positive electrode active material layer in the fully discharged state of the battery cell Example 1 1,5 2,5 4 7:3 330 Example 2 1,5 2 3,5 7:3 330 Example 3 1,5 3,5 5 7:3 330 Example 4 1,5 1 2,5 7:3 330 Example 5 1,5 4,5 6 7:3 330 Example 6 2,5 2,5 5 7:3 330 Example 7 1 2,5 3,5 7:3 330 Example 8 1,5 2,5 4 7:3 330 Example 9 1,5 2,5 4 7:3 330 Example 10 1,5 2,5 4 7:3 330 Example 11 1,5 2,5 4 7:3 330 Example 12 1,5 2,5 4 5:5 330 Example 13 1,5 2,5 4 9:1 330 Example 14 1,5 2,5 4 7:3 400 Comparative example 1 1,5 / 4 7:3 300 Comparative example 2 1,5 / 4 7:3 300 Comparative example 3 1,5 / 4 7:3 330 Comparative example 4 1,5 2,5 4 7:3 300 Table 2 OI value of the orientation degree of the negative electrode active material Volume particle size distribution D V 50 (µm) of the negative electrode active material One-sided surface density (mg / 1540.25 mm²) 2 ) the negative electrode film layer in the fully discharged state of the battery cell Cyclic capacity retention rate of the battery after 1000 cycles Example 1 3 19,5 185 92,60 % Example 2 3 19,5 185 92,40 % Example 3 3 19,5 185 92,70 % Example 4 3 19,5 185 89,30 % Example 5 3 19,5 185 92,80 % Example 6 3 19,5 185 92,70 % Example 7 3 19,5 185 92,20 % Example 8 1,3 19,5 185 90,40 % Example 9 5,5 19,5 185 90,80 % Example 10 3 26 185 92,20 % Example 11 3 11 185 90,50 % Example 12 3 19,5 185 93,80 % Example 13 3 19,5 185 87,50 % Example 14 3 19,5 215 89,50 % Comparative example 1 3 19,5 160 81,20 % Comparative example 2 3 19,5 160 85,30 % Comparative example 3 3 19,5 185 80,60 % Comparative example 4 3 19,5 160 92,80 %

[0242] From the comparison between the exemplary embodiments and the comparative examples, it can be seen that the battery cell comprises an electrode assembly and a housing body, wherein the electrode assembly is received in the housing body and the housing body is made of a pouch material. The electrode assembly comprises a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are arranged alternately stacked. The negative electrode sheet comprises a negative electrode current collector, wherein the negative electrode current collector includes a negative electrode current collector section, the edge region of the negative electrode current collector section being provided with a chamfer.The positive electrode sheet comprises a positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode current collector section and a positive electrode tab arranged on one side of the positive electrode current collector section extending along a first direction, the first direction being perpendicular to the thickness direction of the battery cell.The positive electrode sheet further comprises a positive electrode film layer arranged on at least one side of the positive electrode current collection section in the thickness direction of the battery cell. The positive electrode film layer comprises a positive electrode active material layer as well as a first insulating layer and a second insulating layer arranged on the two opposite sides of the positive electrode active material layer in the first direction. The first insulating layer is arranged on a side of the positive electrode active material layer adjacent to the positive electrode tab, and the second insulating layer is arranged on a side of the positive electrode active material layer away from the positive electrode tab. In the fully discharged state of the battery cell, the one-sided areal density of the positive electrode active material layer is 320 mg / 1540.25 mm². 2This enables the simultaneous achievement of a high volume energy density, a high processing yield and favorable cycle stability of the battery cell.

[0243] From the comparison between embodiment 1 and embodiments 8 to 9, it can be seen that an OI value of the orientation degree of the negative electrode active material in the range of 2.5 to 4 contributes to a further improvement in the cycle performance of the battery cell.

[0244] From the comparison between embodiment 1 and embodiments 10 to 11, it can be seen that a volume particle size distribution D V 50 of the negative electrode active material in the range of 16 µm to 22 µm contributes to a further improvement in the cycle performance of the battery cell. Table 3 Dimension D2 (mm) of the second insulating layer in the first direction Cyclic capacity retention rate of the battery after 1000 cycles Volume energy density of the battery (Wh / L) Example 1 2,5 92,60 % 656 Example 2 2 92,40 % 660 Example 3 3,5 92,70 % 647 Example 4 1 89,30 % 664 Example 5 4,5 92,80 % 640

[0245] From the comparison between embodiments 1 to 2 and embodiments 3 to 5, it can be seen that the dimension D2 of the second insulating layer in the first direction, which is in the range of 2 mm to 3 mm, contributes to a further improvement in the cycle performance and the volume energy density of the battery. Table 4 Dimension D1 (mm) of the first insulating layer in the first direction Cyclic capacity retention rate of the battery after 1000 cycles Volume energy density of the battery (Wh / L) Example 1 1,5 92,60 % 656 Example 6 1,3 92,70 % 643 Example 7 5,5 92,20 % 660

[0246] From the comparison of embodiments 1, 7 and 6, it can be seen that the dimension D1 of the first insulating layer in the first direction, which lies between 1 mm and 2 mm, contributes to further improving the cycle performance of the battery while ensuring the volume energy density. Table 5 Mass ratio of lithium-containing transition metal oxide particles to lithium-containing transition metal phosphate particles Cyclic capacity retention rate of the battery after 1000 cycles Volume energy density of the battery (Wh / L) Example 1 7:3 92,60 % 656 Example 12 5:5 93,80 % 620 Example 13 9:1 87,50 % 690

[0247] From the comparison between embodiment 1 and embodiments 12 to 13, it can be seen that the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles in the range of 6:4 to 8:2 contributes to further improving the cycle performance of the battery cell while simultaneously ensuring the energy density. Table 6 One-sided surface density (mg / 1540.25 mm²) 2 ) the positive electrode active material layer in the fully discharged state of the battery cell One-sided surface density (mg / 1540.25 mm²) 2 ) of the negative electrode film layer in the fully discharged state of the battery cell Cyclic capacity retention rate of the battery after 1000 cycles Volume energy density of the battery (Wh / L) Example 1 330 185 92,60 % 656 Example 14 400 215 89,50 % 730 Comparative example 1 300 160 81,20 % 610 Comparative example 3 330 185 80,60 % 656 Comparative example 4 300 160 92,80 % 600

[0248] From the comparison between example 1 and example 3, it can be seen that in the fully discharged state of the battery cell, if no insulating layer is placed on the side of the positive electrode active material layer that is away from the positive electrode tab, the one-sided areal density of the positive electrode active material layer is greater than or equal to 320 mg / 1540.25 mm². 2is, and the one-sided areal density of the negative electrode active material is greater than or equal to 160 mg / 1540.25 mm² 2 This leads to a deterioration in the battery's cycle performance.

[0249] From a comparison between embodiment 1 and comparative examples 2 to 3, it can be seen that the battery cell comprises an electrode assembly and a housing body, wherein the electrode assembly is received in the housing body and the housing body is made of a pouch material. The electrode assembly comprises a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and the negative electrode sheet are arranged alternately stacked. The negative electrode sheet comprises a negative electrode current collector, wherein the negative electrode current collector includes a negative electrode current collector section, the edge region of the negative electrode current collector section being provided with a chamfer.The positive electrode sheet comprises a positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode current collector section and a positive electrode tab arranged on one side of the positive electrode current collector section extending along a first direction, the first direction being perpendicular to the thickness direction of the battery cell.The positive electrode sheet further comprises a positive electrode film layer arranged on at least one side of the positive electrode current collection section in the thickness direction of the battery cell. The positive electrode film layer comprises a positive electrode active material layer as well as a first insulating layer and a second insulating layer arranged on opposite sides of the positive electrode active material layer in the first direction. The first insulating layer is located on the side of the positive electrode active material layer adjacent to the positive electrode tab, while the second insulating layer is located on the side of the positive electrode active material layer furthest from the positive electrode tab. This contributes to improving the cycle performance of the battery cell while maintaining the volume energy density.

[0250] From the comparison between embodiment 1 and embodiments 14 to 15, it can be seen that in the fully discharged state of the battery cell, the one-sided areal density of the positive electrode active material layer is greater than or equal to 320 mg / 1540.25 mm². 2 Furthermore, the one-sided areal density of the positive electrode active material layer is in the range of 320 mg / 1540.25 mm². 2 up to 400 mg / 1540.25 mm 2 This contributes to further improving the cycle performance of the battery cell while simultaneously ensuring the volume energy density. Table 7 Dimension D1 (mm) of the first insulating layer in the first direction Dimension D2 (mm) of the second insulating layer in the first direction Dimensional difference OH1 (mm) between the negative electrode film layer and the positive electrode active material layer in the first direction Cyclic capacity retention rate of the battery after 1000 cycles Volume energy density of the battery (Wh / L) Comparative example 4 1,5 2,5 4 92,80 % 600 Comparative example 2 1,5 / 4 85,30 % 585

[0251] From the comparison between comparison example 4 and comparison example 2, it can be seen that omitting the chamfer of the positive electrode sheet, arranging a first and a second insulating layer for the positive electrode sheet and achieving OH1 - (D1 + D2) = 0 mm contributes to an improved cycle performance of the battery cell with constant volume energy density.

[0252] It should be noted that the present application is not limited to the embodiments mentioned above. The above embodiments are merely examples, and all embodiments that exhibit essentially the same structure and effect as the technical idea within the technical solution of the present application are all included within the technical scope of the present application. Furthermore, other possibilities in which various modifications conceivable to a person skilled in the art are added to the embodiments, and some components of the embodiments are combined to form other embodiments, are also included within the scope of the present application without departing from the core of the present application. Reference symbol list 1 Positive electrode sheet 11 Positive electrode film layer 111 Positive electrode active material layer 112 First insulating layer 113 Second insulating layer 12 Positive electrode current collector 121 Positive electrode current collection section 122 Positive electrode tab 21 Negative electrode film layer 221 Negative electrode current collection section X First direction Y Second direction Z Thickness direction of the battery cell. 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 202510992931.2

[0001] Cited non-patent literature

[0000] GB / T 19077-2016

[0187]

Claims

Battery cell comprising an electrode assembly and a housing body, wherein the electrode assembly is received in the housing body and the housing body is made of a pouch material; wherein the electrode assembly comprises a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and the negative electrode sheet being arranged stacked alternately; wherein the negative electrode sheet comprises a negative electrode current collector, the negative electrode current collector comprising a negative electrode current collector section, the edge region of the negative electrode current collector section being chamfered;wherein the positive electrode sheet comprises a positive electrode current collector, wherein the positive electrode current collector comprises a positive electrode current collector section and a positive electrode tab arranged on one side of the positive electrode current collector section extending along a first direction, the first direction being perpendicular to the thickness direction of the battery cell;and wherein the positive electrode sheet further comprises a positive electrode film layer arranged on at least one side of the positive electrode current collection section in the thickness direction of the battery cell, wherein the positive electrode film layer comprises a positive electrode active material layer as well as a first insulating layer and a second insulating layer arranged on the two opposite sides of the positive electrode active material layer in the first direction, wherein the first insulating layer is arranged on a side of the positive electrode active material layer adjacent to the positive electrode tab, and the second insulating layer is arranged on a side of the positive electrode active material layer away from the positive electrode tab;and wherein, in the fully discharged state of the battery cell, the one-sided areal density of the positive electrode active material layer is greater than or equal to 320 mg / 1540.25 mm². Battery cell according to claim 1, wherein the dimension D1 of the first insulating layer in the first direction is 1 mm to 2.5 mm. Battery cell according to claim 1, wherein the dimension D1 of the first insulating layer in the first direction is 1 mm to 2 mm. Battery cell according to claim 1, wherein the dimension D2 of the second insulating layer in the first direction is 1 mm to 4.5 mm. Battery cell according to claim 1, wherein the dimension D2 of the second insulating layer in the first direction is 2 mm to 3 mm. Battery cell according to claim 1, wherein the material of the first insulating layer and the material of the second insulating layer each independently comprise one or more of aluminium oxide, zirconium oxide and titanium oxide. Battery cell according to claim 1, wherein the material of the first insulating layer and the material of the second insulating layer each comprise aluminium oxide. Battery cell according to claim 1, wherein the phase comprises an R-phase or a C-phase. Battery cell according to claim 1, wherein the chamfer is an R-chamfer. Battery cell according to claim 1, wherein the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction satisfies the condition 2 mm ≤ OH1 ≤ 6 mm. Battery cell according to claim 10, wherein the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction satisfies the condition 2 mm ≤ OH1 ≤ 5 mm. Battery cell according to claim 10, wherein the dimensional difference OH1 between the negative electrode film layer and the positive electrode active material layer in the first direction satisfies the condition OH1 - (D1 + D2) = 0 mm, where D1 is the dimension of the first insulating layer in the first direction and D2 is the dimension of the second insulating layer in the first direction. Battery cell according to claim 10, wherein the dimensional difference OH2 between the negative electrode film layer and the positive electrode active material layer in the second direction satisfies the condition 1 mm ≤ OH2 ≤ 3 mm, wherein any two of the first direction, the second direction and the thickness direction of the battery cell are perpendicular to each other. Battery cell according to claim 1, wherein in the fully discharged state of the battery cell the one-sided areal density of the positive electrode active material layer is 320 mg / 1540.25 mm2 to 400 mg / 1540.25 mm2. Battery cell according to claim 1, wherein in the fully discharged state of the battery cell the density of the positive electrode active material layer is greater than or equal to 2.3 g / cm3. Battery cell according to claim 1, wherein in the fully discharged state of the battery cell the density of the positive electrode active material layer is 2.3 g / cm3 to 2.6 g / cm3. Battery cell according to claim 1, wherein the positive electrode active material layer comprises a positive electrode active material, wherein the positive electrode active material comprises a lithium-containing transition metal oxide particle and a lithium-containing transition metal phosphate particle. Battery cell according to claim 17, wherein the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles is 5:5 to 9:

1. Battery cell according to claim 17, wherein the mass ratio of the lithium-containing transition metal oxide particles to the lithium-containing transition metal phosphate particles is 6:4 to 8:

2. Battery cell according to claim 17, wherein the lithium-containing transition metal oxide particle comprises a component represented by the following general formula: Lia1Nix1Coy1M1z1M2w1O2-b1Formula I, wherein M1 comprises one or more of Mn and Al, M2 comprises one or more of Zr, B, Mg, Ti, W, Mo, Nb, Ta, Sr, Sb and K, wherein 0.8 ≤ a1 ≤ 1.2, 0 ≤ x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ z1 ≤ 1, 0 ≤ w1 ≤ 0.1, -0.1 ≤ b1 ≤ 0.

1. Battery cell according to claim 17, wherein the lithium-containing transition metal phosphate particle comprises a component represented by the following general formula: LixAyMeaMbP1-cXcYzFormula II, where 0.1 ≤ x ≤ 1.3, 0 ≤ y ≤ 1.3 and 0.8 ≤ x + y ≤ 1.3; 0.9 ≤ a ≤ 1.5, 0 ≤ b ≤ 0.5 and 0.9 ≤ a + b ≤ 1.5; 0 ≤ c ≤ 0.5; 3 ≤ z ≤ 5; A comprises one or more of Na, K and Mg; Me comprises one or more of Mn, Fe, Co and Ni; M comprises one or more of B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La and Ce; X comprises one or more of S, Si, Cl, B, C and N; and Y comprises one or more of O and F. Battery cell according to claim 17, wherein the lithium-containing transition metal phosphate particle comprises one or more of lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate fluoride, lithium manganese iron phosphate, lithium iron phosphate fluoride, lithium manganese iron phosphate fluoride and modified materials thereof. Battery cell according to claim 17, wherein the lithium-containing transition metal phosphate particle comprises one or more lithium manganese iron phosphate and its modified materials. Battery cell according to claim 1, wherein the negative electrode sheet further comprises a negative electrode film layer arranged on at least one side of the negative electrode current collection section in the thickness direction of the battery cell, wherein in the fully discharged state of the battery cell the one-sided areal density of the negative electrode film layer is greater than or equal to 160 mg / 1540.25 mm2. Battery cell according to claim 24, wherein the one-sided areal density of the negative electrode film layer is 180 mg / 1540.25 mm2 to 200 mg / 1540.25 mm2. Battery cell according to claim 24, wherein in the fully discharged state of the battery cell the density of the negative electrode film layer is greater than or equal to 1.4 g / cm3. Battery cell according to claim 24, wherein in the fully discharged state of the battery cell the density of the negative electrode film layer is 1.4 g / cm3 to 1.6 g / cm3. Battery cell according to claim 24, wherein the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises graphite. Battery cell according to claim 24, wherein the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises one or more of natural flake graphite, artificial graphite and microcrystalline graphite. Battery cell according to claim 28, wherein the OI value of the orientation degree of the negative electrode active material is 1.3 to 5.5, wherein the OI value = I004 / I110 applies, where I004 is the integral surface of the diffraction peak of the 004 crystal plane in the X-ray diffraction analysis and I110 is the integral surface of the diffraction peak of the 110 crystal plane. Battery cell according to claim 30, wherein the OI value of the orientation degree of the negative electrode active material is 2.5 to 4. Battery cell according to one of claims 28 to 31, wherein the volume particle size distribution DV50 of the negative electrode active material is 16 µm to 22 µm. Battery device comprising a battery cell according to any one of claims 1 to 32. Power-consuming device, wherein the power-consuming device comprises a battery device according to claim 33, wherein the battery device serves to provide electrical energy. Energy storage device, wherein the energy storage device comprises a battery device according to claim 33, wherein the battery device serves to store electrical energy.

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