Battery pack and electric device

Abstract

Embodiments of the present application disclose a battery pack and an electric device, wherein the battery pack comprises a box body provided with a containing cavity and a battery assembly accommodated in the containing cavity; the battery assembly comprises a plurality of single batteries, and each single battery has a first outer wall surface, a second outer wall surface, a third outer wall surface and a corner portion; each single battery is arranged along a circumferential direction, and each single battery has a target corner portion which is directed to the center of the circumferential direction; the battery assembly has a central circular arc which is circumscribed on the target corner portion of each single battery which is directed to the center of the circumferential direction, and the radius of the central circular arc is R mm, and 12.5 mm≤R≤20 mm is satisfied. According to the present application, the single batteries are arranged compactly in the box body, the volume utilization of the single batteries in the battery pack is improved, and the energy density of the battery pack is improved, so that the capacity of the battery pack is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery pack and electrical device. Background Technology

[0002] With the rapid development of the new energy industry, battery packs with high energy density, long cycle life, and high safety performance have been widely used and developed. Furthermore, there is an urgent need for lithium-ion batteries with larger capacity, greater durability, and longer driving range. Battery pack capacity is one of the core performance characteristics of a battery pack. Therefore, how to improve battery pack capacity has become a pressing issue that needs to be addressed. Summary of the Invention

[0003] Embodiments of this application provide a battery pack and an electrical device to increase the capacity of the battery pack.

[0004] To address the aforementioned technical problems, embodiments of this application disclose the following technical solutions: On one hand, a battery pack is provided, comprising: a housing having a receiving cavity; and The battery pack is housed within the receiving cavity; The battery pack includes multiple individual cells, and each individual cell has a first outer wall surface, a second outer wall surface, a third outer wall surface, and a corner portion. The first outer wall surface, the second outer wall surface, and the third outer wall surface are distributed circumferentially along the individual cell and are connected in pairs through the corner portion to form a closed surface. The first outer wall surface, the second outer wall surface, and the third outer wall surface are arranged at an angle to each other, and at least two of the first outer wall surface, the second outer wall surface, and the third outer wall surface form an acute angle. The battery pack has a central arc, and each individual cell in the battery pack has a target corner portion facing the center of the central arc; the central arc is tangent to the target corner portion of each individual cell facing the center of the central arc, and the radius of the central arc is Rmm, satisfying: 12.5mm≤Rmm≤20mm.

[0005] In addition to one or more of the features disclosed above, or alternatively, the central angle of the central arc is 360°; and / or, The central angle of the central arc is 180°.

[0006] In addition to one or more of the features disclosed above, or alternatively, the angle between the first outer wall surface and the second outer wall surface is greater than the angle between the first outer wall surface and the third outer wall surface and the angle between the second outer wall surface and the third outer wall surface. The battery pack satisfies at least one of the following conditions: (I) The two first outer wall surfaces of two adjacent single cells are arranged opposite to each other; (II) The two second outer wall surfaces of two adjacent single cells are arranged opposite to each other; (III) The first outer wall surface and the second outer wall surface of two adjacent single cells are arranged opposite to each other; (IV) The two third outer wall surfaces of two adjacent single cells are arranged opposite each other.

[0007] In addition to one or more of the features disclosed above, or as an alternative, two adjacent individual cells are arranged at intervals, and the distance between two adjacent individual cells is Hmm, satisfying: 5mm≤Hmm≤8mm.

[0008] In addition to one or more of the features disclosed above, or alternatively, the single cell has a first direction, a second direction, and a third direction that intersect each other in pairs; The single battery includes: a housing and an electrode assembly, wherein the electrode assembly is housed within the housing, and the housing has a first outer wall surface, a second outer wall surface, and a third outer wall surface connected in sequence. The length of the first outer wall surface in the first direction is L1mm, the length of the second outer wall surface in the second direction is L2mm, and the length of the third outer wall surface in the third direction is L3mm, satisfying: 0.7≤L1 / L2≤1.43, and / or, 0.5≤L3 / 2L1≤0.865.

[0009] In addition to one or more of the features disclosed above, or alternatively, the length L1mm of the first outer wall surface in the first direction also satisfies: 70mm ≤ L1mm ≤ 100mm; and / or, The length L2mm of the second outer wall surface in the second direction also satisfies: 70mm≤L2mm≤100mm; and / or, The length L3mm of the third outer wall surface in the third direction also satisfies: 70mm≤L3mm≤173mm.

[0010] In addition to one or more of the features disclosed above, or alternatively, the length L1mm of the first outer wall surface in the first direction also satisfies: 80mm ≤ L1mm ≤ 90mm; and / or, The length L2mm of the second outer wall surface in the second direction also satisfies: 80mm≤L2mm≤90mm; and / or, The length L3mm of the third outer wall surface in the third direction also satisfies: 80mm≤L3mm≤155mm.

[0011] In addition to one or more of the features disclosed above, or alternatively, the included angle between the first outer wall surface and the second outer wall surface is α, satisfying: 60°≤α≤120°; and / or, The angle between the first outer wall surface and the third outer wall surface is β, satisfying: 30°≤β≤60°; and / or, The angle between the second outer wall surface and the third outer wall surface is λ, which satisfies: 30°≤λ≤60°.

[0012] In addition to one or more of the features disclosed above, or alternatively, the included angle α between the first outer wall surface and the second outer wall surface also satisfies: 80° ≤ α ≤ 100°; and / or, The included angle β between the first outer wall surface and the third outer wall surface also satisfies: 40°≤β≤50°; and / or, The included angle λ between the second outer wall surface and the third outer wall surface also satisfies: 40°≤λ≤50°.

[0013] In addition to one or more of the features disclosed above, or alternatively, the single cell also has a fourth direction that intersects the first direction, the second direction and the third direction in pairs, and a reference plane perpendicular to the fourth direction; The single-cell battery further includes: an end cap disposed at at least one end of the housing in the fourth direction and connected to the housing; and An explosion-proof valve is installed on the end cap; Wherein, along the fourth direction, the orthographic projection area of ​​the end cap on the reference plane is S1mm. 2 The orthographic projection area of ​​the explosion-proof valve on the reference plane is S²mm. 2 The condition is satisfied that 0.05 ≤ S2 / S1 ≤ 0.15.

[0014] In addition to one or more of the features disclosed above, or as an alternative, the electrode assembly has a first electrode segment and a second electrode segment connected to each other, the included angle between the first electrode segment and the second electrode segment being γ, satisfying: 90°≤γ≤180°.

[0015] In addition to one or more of the features disclosed above, or alternatively, the included angle γ between the first electrode segment and the second electrode segment also satisfies: 120°≤γ≤150°.

[0016] On the other hand, a further electrical device is disclosed, which, in addition to one or more of the features disclosed above, or as an alternative, includes a battery pack as described in any of the preceding claims, the battery pack serving as a power source for the electrical device.

[0017] One of the above technical solutions has the following advantages or beneficial effects: This application controls the target corner portion of the central arc tangent to the center of each individual battery cell in the circumferential direction, that is, the target corner portion of the individual battery cell is arranged along the central arc, while controlling the radius Rmm of the central arc within the range of 12.5mm to 20mm, so that the individual batteries are arranged compactly in the battery pack, improving the volume utilization rate of the individual batteries in the battery pack, thereby improving the energy density of the battery pack and thus increasing the capacity of the battery pack; at the same time, this application uses triangular batteries for the individual batteries to improve the structural strength of the individual batteries, thereby improving the overall structural strength of the battery pack, and ultimately improving the safety performance of the battery pack. Attached Figure Description

[0018] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0019] Figure 1 This is a three-dimensional structural view of the battery pack provided according to an embodiment of this application; Figure 2 This is an exploded structural view of a battery pack according to an embodiment of this application; Figure 3 This is a structural diagram showing the arrangement of multiple individual cells according to an embodiment of this application; Figure 4 This is a structural diagram of multiple individual cells arranged in a circle according to another embodiment of this application; Figure 5 This is a three-dimensional structural view of a single battery cell provided according to an embodiment of this application; Figure 6 This is a structural diagram of one arrangement of a single battery cell according to an embodiment of this application; Figure 7 This is a structural diagram of another arrangement of a single battery cell according to an embodiment of this application; Figure 8 This is a structural diagram of another arrangement of a single battery cell according to an embodiment of this application; Figure 9 This is a structural diagram of another arrangement of a single battery cell according to an embodiment of this application; Figure 10 This is a top view of a single battery cell provided according to an embodiment of this application; Figure 11 This is a three-dimensional structural view of a single battery cell provided according to an embodiment of this application; Figure 12 This is a structural diagram of the housing and electrode assembly provided according to an embodiment of this application; Figure 13This is a structural diagram of the housing and electrode assembly provided according to another embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 100. Battery pack; 110. Box body; 111. Receiving cavity; 120. Single cell; 121. Housing; 1211. First outer wall surface; 1212. Second outer wall surface; 1213. Third outer wall surface; 1214. Corner portion; 12141. Target corner portion; 122. Electrode assembly; 1221. First electrode segment; 1222. Second electrode segment; 123. End cap; 124. Explosion-proof valve; 130. Central arc; 140. Top cover; 150. Battery management components. Detailed Implementation

[0021] To make the objectives, technical solutions, and beneficial effects of this application clearer, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this application. It should be understood that the specific embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0022] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] With the rapid development of the new energy industry, the technology of batteries used in electric vehicles is constantly innovating, resulting in a growing variety of battery pack envelopes with diverse shapes. Existing square, blade, or cylindrical batteries have certain limitations in battery pack layout, failing to meet the arrangement requirements of various battery pack envelope formats and effectively filling irregularly shaped areas within the battery pack. This leads to incomplete space utilization, reduced volume utilization, and lower battery pack capacity. Furthermore, the structural stability of existing battery packs after assembly is relatively poor, affecting battery pack safety.

[0026] To address the aforementioned problems, this application provides a battery pack 100 in its embodiments. For details, please refer to... Figures 1 to 13 The battery pack 100 includes: a housing 110, a battery pack and a top cover 140. The housing 110 is provided with a receiving cavity 111, the battery pack is housed in the receiving cavity 111, and the top cover 140 closes the housing 110 to seal the housing 110.

[0027] Specifically, the battery pack includes multiple individual cells 120. Each individual cell 120 has a first outer wall surface 1211, a second outer wall surface 1212, a third outer wall surface 1213, and a corner portion 1214. The first outer wall surface 1211, the second outer wall surface 1212, and the third outer wall surface 1213 are distributed circumferentially along the individual cell 120 and are connected in pairs through the corner portion 1214 to form a closed surface. Among the first outer wall surface 1211, the second outer wall surface 1212, and the third outer wall surface 1213... The outer wall surfaces 1211, 1212, and 1213 are arranged at an angle to each other, and the included angle between at least two of them is an acute angle. That is, the outer wall surfaces 1211, 1212, and 1213 together form a triangular structure. The sum of the included angles between any two of the outer wall surfaces 1211, 1212, and 1213 is 180°. The single cell 120 in this application is a triangular cell. The single cell 120 can be a rechargeable battery, which refers to a single cell that can be recharged after discharge to activate the active materials and continue to be used. For example, the single cell 120 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, or nickel-cadmium battery, but is not limited to these.

[0028] The aforementioned corner portion 1214 can be a rounded chamfer, a planar chamfer, or any other chamfer shape. This application does not impose specific limitations and can be configured according to the actual situation.

[0029] Specifically, the battery pack has a central arc 130. In the battery pack, each individual cell 120 has a target corner portion 12141 facing the center of the central arc 130. The central arc 130 is tangent to the target corner portions 12141 of each individual cell 120 facing the center of the central arc 130. The radius of the central arc 130 is Rmm, satisfying: 12.5mm ≤ Rmm ≤ 20mm, that is, the radius Rmm of the central arc 130 can be controlled within the range of 12.5mm to 20mm. For example, the radius Rmm of the central arc 130 can be one of 12.5mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm, or any combination thereof. It is worth noting that the above-mentioned specific values ​​of the radius Rmm of the central arc 130 are only given as examples; any value within the range of 12.5mm to 20mm is within the protection scope of this application.

[0030] The radius Rmm of the central arc 130 can be obtained by disassembling the actual battery pack 100, placing the battery pack in the battery pack 100 within the measurement space of a three-dimensional measuring instrument, using the three-dimensional measuring instrument to obtain the coordinate positions of the target corners 12141 of each individual battery 120 in the battery pack, and then directly generating the shape of the central arc 130 and directly calculating the radius value of the central arc 130 based on the spatial coordinate values ​​of each target corner 12141.

[0031] Understandably, this application controls the target corner portion 12141 of the central arc 130 to be tangent to the center of each individual battery cell 120 in the circumferential direction, that is, the target corner portion 12141 of the individual battery cells 120 is arranged along the central arc 130, while controlling the radius Rmm of the central arc 130 within the range of 12.5mm to 20mm, so that the individual battery cells 120 are arranged compactly within the housing 110, improving the volume utilization rate of the individual battery cells 120 in the battery pack 100, thereby improving the energy density of the battery pack 100 and increasing the capacity of the battery pack 100; at the same time, this application also... The individual cells 120 of the battery pack 100 are triangular, allowing them to be placed in irregular areas of the housing 110. This further improves the volume utilization of the individual cells 120 in the battery pack 100, increases the energy density of the battery pack 100, and enhances its capacity. Furthermore, due to the good structural stability of triangles, the use of triangular cells for the individual cells 120 in this application improves their structural strength, thereby enhancing the overall structural strength of the battery pack 100 and ultimately improving its safety performance.

[0032] In one embodiment, please refer to Figure 3 The central angle of the central arc 130 can be 360°. At this time, the battery pack formed by multiple individual cells 120 has a square structure, so as to improve the volume utilization rate of the individual cells 120 in the battery pack 100, thereby improving the energy density of the battery pack 100.

[0033] Please refer to Figure 4 The central angle of the central arc 130 can also be 180°. In this case, the battery pack formed by multiple individual cells 120 is in the form of a triangular structure, so that the battery pack can be placed in the irregular area of ​​the box 110 to improve the volume utilization rate of the individual cells 120 in the battery pack 100, thereby improving the energy density of the battery pack 100.

[0034] The central angle of the central arc 130 can be determined by disassembling the actual battery pack 100, placing the battery pack within the battery group in the measurement space of a three-dimensional measuring instrument, obtaining the coordinate positions of the target corner portions 12141 of each individual battery cell 120 in the battery group using the three-dimensional measuring instrument, and then directly generating the shape of the central arc 130 and calculating the central angle value of the central arc 130 based on the spatial coordinate values ​​of each target corner portion 12141. In one embodiment, the target corner portion 12141 is an arc.

[0035] It should be understood that the central angle of the central arc 130 in this application is not limited to 360° or 180°. In order to accommodate the individual battery 120 in any irregularly shaped box 110, any number of individual batteries 120 can be arranged to enclose the central arc 130 at any angle. For example, the central angle of the enclosed central arc 130 can be 90°, 120° or 150°, etc., but is not limited to this.

[0036] In one embodiment, please refer to Figure 5 The included angle between the first outer wall surface 1211 and the second outer wall surface 1212 is greater than the included angle between the first outer wall surface 1211 and the third outer wall surface 1213 and the included angle between the second outer wall surface 1212 and the third outer wall surface 1213. That is, the size of the third outer wall surface 1213 is greater than the size of the first outer wall surface 1211 and the second outer wall surface 1212.

[0037] For further details, please refer to Figure 8 In the battery pack, the two first outer wall surfaces 1211 of two adjacent individual cells 120 can be arranged opposite each other; please refer to Figure 7 The two second outer wall surfaces 1212 of two adjacent single cells 120 can also be arranged relative to each other; please refer to Figure 9 The first outer wall surface 1211 and the second outer wall surface 1212 of two adjacent single cells 120 can also be arranged relative to each other; please refer to Figure 6 Furthermore, the two third outer wall surfaces 1213 of two adjacent individual cells 120 can also be arranged opposite each other. That is, any two outer wall surfaces of two adjacent individual cells 120 can be arranged opposite each other, meaning that two adjacent individual cells 120 can be assembled and assembled arbitrarily to ensure that two adjacent individual cells 120 can form any shape, suitable for assembly into housings 110 of different shapes, and have versatility.

[0038] In one embodiment, two adjacent individual battery cells 120 are arranged at intervals, and the distance between two adjacent individual battery cells 120 is Hmm, satisfying: 5mm ≤ Hmm ≤ 8mm. That is, the distance Hmm between two adjacent individual battery cells 120 can be controlled within the range of 5mm to 8mm. For example, the distance Hmm between two adjacent individual battery cells 120 can be one of 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, or 8mm, or any combination thereof. It is worth noting that the specific value of the distance Hmm is given above as an example only, and any value within the range of 5mm to 8mm is within the protection scope of this application. The distance Hmm between two adjacent individual cells 120 can be obtained by disassembling the actual battery pack 100 and measuring the distance between the two adjacent outer walls of two adjacent individual cells 120 multiple times using a measuring tool, and then calculating the average value. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to these.

[0039] This application controls the spacing Hmm between two adjacent individual cells 120 within the range of 5mm to 8mm to ensure that the spacing between individual cells 120 in the battery pack 100 is reasonably set. This ensures the safety performance of the battery pack while making the individual cells 120 more compactly arranged in the housing 110, thereby improving the volume utilization rate of the individual cells 120 in the battery pack 100 and thus increasing the energy density of the battery pack 100.

[0040] In one embodiment, the battery pack 100 further includes a battery management element 150, which is disposed inside the housing 110 and electrically connected to the individual battery 120 to monitor and manage the individual battery 120 inside the housing 110 of the battery pack 100, thereby improving the safety performance of the battery pack 100.

[0041] Specifically, the battery management element 150 can be any of the following: a battery pack circuit breaker or a battery management unit.

[0042] In one embodiment, please refer to Figures 5 to 13 The aforementioned single-cell battery 120 has four intersecting directions: a first direction X, a second direction Y, a third direction P, and a fourth direction Z. Specifically, the first direction X, the second direction Y, and the fourth direction Z are perpendicular to each other. "Perpendicular" here includes not only absolute perpendicularity but also approximate perpendicularity as commonly understood in engineering, such as when the angle between two lines, a line and a surface, or a surface is between 89° and 91°.

[0043] For details, please refer to Figures 12 to 13The single cell 120 includes: a housing 121 and an electrode assembly 122. The electrode assembly 122 is housed in the housing 121. The housing 121 has a first outer wall surface 1211, a second outer wall surface 1212 and a third outer wall surface 1213 connected in sequence.

[0044] The housing 121 may be made of a strong material such as metal, but is not limited to this. For example, the housing 121 may be made of aluminum profile, but is not limited to this.

[0045] The aforementioned single-cell battery 120 also includes an electrolyte, a positive electrode post, a negative electrode post, and other functional components. The electrolyte can be a conventional electrolyte or a special electrolyte with additives. The electrolyte is used to wet the electrode assembly 122. The electrode assembly 122 is the component in the single-cell battery 120 where electrochemical reactions occur, and there can be one or more electrode assemblies 122. The electrode assembly 122 is mainly formed by winding or stacking a positive electrode sheet, a separator, and a negative electrode sheet. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly, the portions of the positive electrode sheet without active material constitute the positive tab, and the portions of the negative electrode sheet without active material constitute the negative tab. During the charging and discharging process of the single-cell battery 120, the positive and negative active materials react with the electrolyte, the positive tab is electrically connected to the positive electrode post, and the negative tab is electrically connected to the negative electrode post to form a current loop, enabling the single-cell battery 120 to function normally.

[0046] For details, please refer to Figure 10 The length of the first outer wall surface 1211 in the first direction X is L1 mm, and the length of the second outer wall surface 1212 in the second direction Y is L2 mm, satisfying: 0.7 ≤ L1 / L2 ≤ 1.43. That is, the ratio of the length L1 mm of the first outer wall surface 1211 in the first direction X and the length L2 mm of the second outer wall surface 1212 in the second direction Y can be controlled within the range of 0.7 to 1.43. For example, L1 / L2 can be any combination of 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, or 1.43. It is worth noting that the specific values ​​of the ratio L1 / L2 given above are merely illustrative examples, and any value within the range of 0.7 to 1.43 is within the protection scope of this application.

[0047] The length L1mm of the first outer wall surface 1211 in the first direction X and the length L2mm of the second outer wall surface 1212 in the second direction Y can be obtained by disassembling the actual battery pack 100 and measuring the dimensions of the first outer wall surface 1211 in the first direction X and the second outer wall surface 1212 in the second direction Y of any single battery cell 120 in the battery pack 100 multiple times using a measuring tool, and then calculating the average value of each measurement. The measuring tool can be any one of a ruler, vernier caliper, or other dimensional measuring instruments, but is not limited to this.

[0048] This application controls the ratio of the length L1mm of the first outer wall surface 1211 in the first direction X and the length L2mm of the second outer wall surface 1212 in the second direction Y within the range of 0.7 to 1.43, so as to reasonably design the structural dimensions of the individual battery 120. This allows the individual batteries 120 to be assembled into a battery pack and assembled into a box 110 of different shapes, which is versatile. At the same time, it improves the volume utilization rate of the individual batteries 120 in the box 110 and increases the energy density of the battery pack 100. Furthermore, it allows the individual batteries 120 to fit tightly together after being assembled, which improves the overall structural stability of the battery pack 100 and thus improves the safety performance of the battery pack 100.

[0049] Please refer to this again. Figure 10 The length of the third outer wall surface 1213 in the third direction P is L3 mm, satisfying: 0.5 ≤ L3 / 2L1 ≤ 0.865. That is, L3 / 2L1 can be controlled within the range of 0.5 to 0.865. For example, L3 / 2L1 can be one of 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, or 0.865, or any combination of two of them. It is worth noting that the specific values ​​of L3 / 2L1 given above are only illustrative examples, and any value within the range of 0.5 to 0.865 is within the protection scope of this application. This application controls the parameter relationship L3 / 2L1 between the length L3mm of the third outer wall surface 1213 in the third direction P and the length L1mm of the first outer wall surface 1211 in the first direction X within the range of 0.5 to 0.865, so as to further rationally design the structural dimensions of the individual battery 120. This allows the individual batteries 120 to be assembled into a battery pack and assembled into a box 110 of different shapes, which has versatility. At the same time, it improves the volume utilization rate of the individual batteries 120 in the box 110 and increases the energy density of the battery pack 100. Furthermore, it allows the individual batteries 120 to fit tightly together after being assembled, improving the overall structural stability of the battery pack 100 and thus improving the safety performance of the battery pack 100.

[0050] The measurement method for the length L3mm of the third outer wall surface 1213 in the third direction P is the same as that for the length L1mm of the first outer wall surface 1211 in the first direction X and the length L2mm of the second outer wall surface 1212 in the second direction Y. It will not be elaborated here, but can be referred to the above description.

[0051] In one embodiment, the length L1mm of the first outer wall surface 1211 in the first direction X further satisfies: 70mm ≤ L1mm ≤ 100mm. That is, the length L1mm of the first outer wall surface 1211 in the first direction X can be controlled within the range of 70mm to 100mm. For example, the length L1mm of the first outer wall surface 1211 in the first direction X can be one of 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, or 100mm, or any combination thereof. It is worth noting that the specific value of the length L1mm mentioned above is only given as an example, and any value within the range of 70mm to 100mm is within the protection scope of this application.

[0052] Preferably, the length L1mm of the first outer wall surface 1211 in the first direction X also satisfies: 80mm ≤ L1mm ≤ 90mm. That is, the length L1mm of the first outer wall surface 1211 in the first direction X can be controlled within the range of 80mm to 90mm. For example, the length L1mm of the first outer wall surface 1211 in the first direction X can be one of 80mm, 81mm, 82mm, 83mm, 84mm, 85mm, 86mm, 87mm, 89mm, or 90mm, or any combination thereof. It is worth noting that the specific value of the length L1mm mentioned above is only given as an example, and any value within the range of 70mm to 100mm is within the protection scope of this application.

[0053] Understandably, this application controls the length L1mm of the first outer wall surface 1211 in the first direction X within the range of 70mm to 100mm, and further controls the length L1mm of the first outer wall surface 1211 in the first direction X within the range of 80mm to 90mm, so as to further rationally design the structural dimensions of the single battery 120, so as to ensure that the volume utilization rate of the single battery 120 in the housing 110 can be improved when the single battery 120 is housed in the housing 110, thereby improving the energy density of the battery pack 100; at the same time, it can make the single batteries 120 fit tightly after being assembled, improving the overall structural stability of the battery pack 100, thereby improving the safety performance of the battery pack 100.

[0054] In one embodiment, the length L2mm of the second outer wall surface 1212 in the second direction Y also satisfies: 70mm ≤ L2mm ≤ 100mm. That is, the length L2mm of the second outer wall surface 1212 in the second direction Y can be controlled within the range of 70mm to 100mm. For example, the length L2mm of the second outer wall surface 1212 in the second direction Y can be one of 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, or 100mm, or any combination thereof. It is worth noting that the specific value of the length L2mm mentioned above is only given as an example, and any value within the range of 70mm to 100mm is within the protection scope of this application.

[0055] Preferably, the length L2mm of the second outer wall surface 1212 in the second direction Y also satisfies: 80mm ≤ L2mm ≤ 90mm. That is, the length L2mm of the second outer wall surface 1212 in the second direction Y can be controlled within the range of 80mm to 90mm. For example, the length L2mm of the second outer wall surface 1212 in the second direction Y can be one of 80mm, 81mm, 82mm, 83mm, 84mm, 85mm, 86mm, 87mm, 89mm, or 90mm, or any combination thereof. It is worth noting that the above-mentioned specific value of the length L2mm is only given as an example, and any value within the range of 70mm to 100mm is within the protection scope of this application.

[0056] Understandably, this application controls the length L2mm of the second outer wall surface 1212 in the second direction Y within the range of 70mm to 100mm, and further controls the length L2mm of the second outer wall surface 1212 in the second direction Y within the range of 80mm to 90mm, so as to further rationally design the structural dimensions of the single battery 120, further ensuring that the volume utilization rate of the single battery 120 in the housing 110 can be improved when the single battery 120 is housed in the housing 110, thereby improving the energy density of the battery pack 100; at the same time, it enables the single batteries 120 to fit tightly after being assembled, improving the overall structural stability of the battery pack 100, thereby improving the safety performance of the battery pack 100.

[0057] In one embodiment, the length L3mm of the third outer wall surface 1213 in the third direction P also satisfies: 70mm ≤ L3mm ≤ 173mm. That is, the length L3mm of the third outer wall surface 1213 in the third direction P can be controlled within the range of 70mm to 173mm. For example, the length L3mm of the third outer wall surface 1213 in the third direction P can be one of 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, or 173mm, or any combination thereof. It is worth noting that the specific value of the length L3mm mentioned above is only given as an example, and any value within the range of 70mm to 173mm is within the protection scope of this application.

[0058] Preferably, the length L3mm of the third outer wall surface 1213 in the third direction P also satisfies: 80mm ≤ L3mm ≤ 155mm. That is, the length L3mm of the third outer wall surface 1213 in the third direction P can be controlled within the range of 80mm to 155mm. For example, the length L3mm of the third outer wall surface 1213 in the third direction P can be one of 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, or 155mm, or any combination thereof. It is worth noting that the above-mentioned specific value of the length L3mm is only given as an example, and any value within the range of 80mm to 155mm is within the protection scope of this application.

[0059] Understandably, this application controls the length L3mm of the third outer wall surface 1213 in the third direction P within the range of 70mm to 173mm, and further controls the length L3mm of the third outer wall surface 1213 in the third direction P within the range of 80mm to 155mm, so as to further rationally design the structural dimensions of the single battery 120, further ensure that the volume utilization rate of the single battery 120 in the housing 110 can be improved when the single battery 120 is housed in the housing 110, thereby improving the energy density of the battery pack 100; at the same time, it enables the single batteries 120 to fit tightly after being assembled, improving the overall structural stability of the battery pack 100, thereby improving the safety performance of the battery pack 100.

[0060] In one embodiment, please refer again Figure 10The included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 satisfies: 60° ≤ α ≤ 120°. That is, the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 can be controlled within the range of 60° to 120°. For example, the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 can be one of 60°, 70°, 80°, 90°, 100°, 110°, or 120°, or any combination thereof. It is worth noting that the specific value of the included angle α given above is only illustrative; any value within the range of 60° to 120° is within the protection scope of this application.

[0061] Preferably, the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 also satisfies: 80°≤α≤100°. That is, the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 can be controlled within the range of 80° to 100°. For example, the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 can be one of 80°, 84°, 88°, 90°, 92°, 96° or 100° or any combination thereof. It is worth noting that the specific values ​​of the included angle α mentioned above are only given as examples, and any value within the range of 80° to 100° is within the protection scope of this application.

[0062] The included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 can be obtained by first disassembling the battery pack 100, then measuring the included angle between the first outer wall surface 1211 and the second outer wall surface 1212 of the individual battery 120 inside the battery pack 100 multiple times using a measuring tool and calculating the average value. The measuring tool can be an angle measuring instrument.

[0063] Understandably, this application controls the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 within the range of 60° to 120°, and further controls the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 within the range of 80° to 100°, so as to further rationally design the structural dimensions of the single battery cell 120, so as to ensure that the single battery cell 120 is accommodated in the irregular area within the housing 110, thereby improving the volume utilization rate of the single battery cell 120 within the housing 110, and ultimately improving the energy density of the battery pack 100; at the same time, it enables the single battery cells 120 to fit tightly after being assembled, improving the overall structural stability of the battery pack 100, thereby improving the safety performance of the battery pack 100.

[0064] In one embodiment, please refer again Figure 10The included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 satisfies: 30° ≤ β ≤ 60°. That is, the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 can be controlled within the range of 30° to 60°. For example, the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 can be one of 30°, 35°, 40°, 45°, 50°, 55°, or 60°, or any combination thereof. It is worth noting that the specific value of the included angle β mentioned above is only given as an example; any value within the range of 30° to 60° is within the protection scope of this application.

[0065] Preferably, the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 also satisfies: 40° ≤ β ≤ 50°. That is, the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 can be controlled within the range of 40° to 50°. For example, the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 can be one of 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49° or 50° or any combination thereof. It is worth noting that the above specific values ​​of the included angle β are only given as examples, and any value within the range of 40° to 50° is within the protection scope of this application.

[0066] The method for measuring the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 is the same as the method for measuring the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212, and will not be elaborated here. Please refer to the above description.

[0067] This application controls the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 within the range of 30° to 60°, and further controls the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 within the range of 40° to 50°, so as to further rationally design the structural dimensions of the single battery cell 120, further ensure that the single battery cell 120 is accommodated in the irregular area within the housing 110, thereby improving the volume utilization rate of the single battery cell 120 within the housing 110, and ultimately improving the energy density of the battery pack 100; at the same time, it enables the single battery cells 120 to fit tightly together after being assembled, improving the overall structural stability of the battery pack 100, and thus improving the safety performance of the battery pack 100.

[0068] In one embodiment, please refer again Figure 10The included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 satisfies: 30° ≤ λ ≤ 60°. That is, the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 can be controlled within the range of 30° to 60°. For example, the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 can be one of 30°, 35°, 40°, 45°, 50°, 55°, or 60°, or any combination thereof. It is worth noting that the specific value of the included angle λ given above is only illustrative; any value within the range of 30° to 60° is within the protection scope of this application.

[0069] Preferably, the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 also satisfies: 40°≤λ≤50°. That is, the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 can be controlled within the range of 40° to 50°. For example, the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 can be one of 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49° or 50° or any combination thereof. It is worth noting that the above specific values ​​of the included angle λ are only given as examples, and any value within the range of 40° to 50° is within the protection scope of this application.

[0070] The method for measuring the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 is the same as the method for measuring the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212, and will not be elaborated here. Please refer to the above description.

[0071] This application controls the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 within the range of 30° to 60°, and further controls the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 within the range of 40° to 50°, so as to further rationally design the structural dimensions of the single battery cell 120, further ensure that the single battery cell 120 is accommodated in the irregular area within the housing 110, thereby improving the volume utilization rate of the single battery cell 120 within the housing 110, and ultimately improving the energy density of the battery pack 100; at the same time, it enables the single battery cells 120 to fit tightly after being assembled, improving the overall structural stability of the battery pack 100, and thus improving the safety performance of the battery pack 100.

[0072] In one embodiment, please refer again Figures 10 to 11 The aforementioned single battery 120 further includes: an end cap 123 and an explosion-proof valve 124. The end cap 123 is disposed at at least one end of the housing 121 in the fourth direction Z, and the end cap 123 is connected to the housing 121; the explosion-proof valve 124 is disposed on the end cap 123.

[0073] The end cap 123 can be provided at any end of the housing 121 in the fourth direction Z, or the end cap 123 can be provided at both ends of the housing 121 in the fourth direction Z. This application does not make specific limitations, and the end cap can be provided according to the actual situation.

[0074] The explosion-proof valve 124 can be formed by directly opening explosion-proof lines on the end cap 123, or it can be a finished explosion-proof valve directly installed on the end cap 123. This application does not make specific limitations and can be set according to the actual situation.

[0075] Specifically, the single cell 120 also has a reference plane A perpendicular to the fourth direction Z; along the fourth direction Z, the orthographic projection area of ​​the end cap 123 on the reference plane A is S1mm. 2 The orthographic projection area of ​​the explosion-proof valve 124 on the reference plane A is S2mm. 2 The condition is satisfied that 0.05 ≤ S2 / S1 ≤ 0.15. That is, the orthogonal projection area of ​​the explosion-proof valve 124 on reference plane A is S2mm². 2 The orthographic projection area of ​​end cap 123 on reference plane A is S1mm. 2 The ratio can be controlled within the range of 0.05 to 0.15. For example, S2 / S1 can be a range of one or any two of the following: 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, or 0.15. It is worth noting that the specific values ​​of the ratio S2 / S1 given above are merely illustrative examples, and any value within the range of 0.05 to 0.15 is within the scope of protection of this application.

[0076] The orthographic projection area of ​​end cap 123 on reference plane A is S1mm. 2 The orthographic projection area of ​​explosion-proof valve 124 on reference plane A is S2mm. 2 The image areas of the end cap 123 and the explosion-proof valve 124 can be measured using projection measurement equipment (such as a digital microscope or image measuring instrument) to obtain the orthographic projection area S1mm of the end cap 123 on the reference plane A. 2 The orthographic projection area of ​​explosion-proof valve 124 on reference plane A is S2mm. 2 However, it is not limited to this.

[0077] This application uses the orthographic projection area S2mm of the explosion-proof valve 124 on reference plane A. 2 The orthographic projection area of ​​end cap 123 on reference plane A is S1mm. 2The ratio is controlled within the range of 0.05 to 0.15 to reasonably set the size of the explosion-proof valve 124 so that it can quickly depressurize when the single cell 120 experiences thermal runaway, effectively guide the gas generated by the thermal runaway of the single cell 120 to be discharged, reduce the possibility of the single cell 120 exploding, improve the safety performance of the single cell 120, and ultimately improve the safety performance of the battery pack 100.

[0078] In one embodiment, please refer again Figures 12 to 13 The electrode assembly 122 has a first electrode segment 1221 and a second electrode segment 1222 connected to each other. The included angle γ between the first electrode segment 1221 and the second electrode segment 1222 satisfies: 90°≤γ≤180°. That is, the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 can be controlled within the range of 90° to 180°. For example, the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 can be one of 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, or 180°, or any combination thereof. It is worth noting that the specific values ​​of the included angle γ mentioned above are only given as examples, and any value within the range of 90° to 180° is within the protection scope of this application.

[0079] Preferably, the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 also satisfies: 120° ≤ γ ≤ 150°. That is, the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 can be controlled within the range of 120° to 150°. For example, the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 can be one of 120°, 125°, 130°, 135°, 140°, 145°, or 150°, or any combination thereof. It is worth noting that the specific values ​​of the included angle γ mentioned above are only given as examples, and any value within the range of 120° to 150° is within the protection scope of this application.

[0080] The angle γ between the first electrode segment 1221 and the second electrode segment 1222 can be obtained by first disassembling the single cell 120, and then repeatedly measuring the angle between the first electrode segment 1221 and the second electrode segment 1222 of the electrode assembly 122 inside the single cell 120 using a measuring tool and calculating the average value. The measuring tool can be an angle measuring instrument.

[0081] This application controls the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 within the range of 90° to 180°, and further controls the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 within the range of 120° to 150°, so that the electrode assembly 122 can be accommodated in different housings 121, which has versatility. At the same time, it can improve the space occupancy rate of the electrode assembly 122 in the housing 121, increase the capacity of the single cell 120, thereby increasing the energy density of the single cell 120, and ultimately increasing the energy density of the battery pack 100.

[0082] On the other hand, in embodiments of this application, an electrical device is also provided, including a battery pack 100 as described in any of the above embodiments, which serves as the power supply for the electrical device. This electrical device may be, but is not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0083] To better understand the technical solution of this application, the following explanation uses a lithium-ion battery pack as an example.

[0084] This embodiment provides a method for preparing a lithium-ion battery pack, the specific process of which is as follows: 1. Preparation of positive electrode sheet Lithium iron phosphate, conductive carbon black SP, and PVDF binder were mixed in a mass ratio of 96:2:2. NMP was then added as a solvent and the mixture was stirred under vacuum until the system was homogeneous to obtain a positive electrode slurry. The positive electrode slurry was uniformly coated on both sides of the positive electrode current collector aluminum foil and then transferred to a 120°C oven for drying. After rolling, slitting, and cutting, the positive electrode sheet was obtained.

[0085] 2. Preparation of negative electrode sheet The negative electrode active material graphite, conductive agent conductive carbon black SP, thickener CMC, and binder SBR are mixed in a mass ratio of 96.2:1.2:1.2:1.4. Then, deionized water is added as a solvent for mixing. The mixture is stirred under vacuum until the system becomes homogeneous to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on both sides of the negative electrode current collector copper foil, and then transferred to a 110°C oven for drying. After that, the negative electrode sheet is obtained by rolling, slitting, and cutting.

[0086] 3. Preparation of electrolyte Ethylene carbonate (EC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a mass ratio of 3:4:3 to obtain an organic solvent. 1 mol / L LiPF6 was added and mixed thoroughly. Then, vinylene carbonate, ethylene sulfate, and lithium difluorophosphate were added to prepare an electrolyte.

[0087] 4. Preparation of the diaphragm PP film is used as the separator.

[0088] 5. Preparation of lithium-ion batteries After drying, the negative and positive electrode sheets prepared by the above steps are used together with the separator to prepare a wound electrode assembly using a winding machine. The different posts on the end caps of the positive and negative electrode tabs are directly welded together, and the welded electrode assembly with the top cap is placed into an aluminum shell for encapsulation. After filling with electrolyte and forming and fixing the volume, a lithium-ion battery is obtained.

[0089] 6. Preparation of lithium-ion battery packs The lithium-ion batteries are assembled into the casing, and the top cover is closed to obtain the lithium-ion battery pack.

[0090] The lithium-ion battery packs in each embodiment and comparative example were prepared according to the above-described preparation method. The structural dimensions and performance test data of each embodiment and comparative example are shown in Table 1 and Table 2.

[0091] The specific testing methods for the batteries prepared in the examples and comparative examples are as follows: 1. Test methods for the structural stability of lithium-ion battery packs At 25℃, the lithium-ion battery pack was left to stand for 30 minutes. Then, the battery pack was fixed on a vibration table and vibrated using a sinusoidal wave, with a logarithmic frequency sweep from 10Hz to 55Hz and back to 7Hz within 15 minutes. Vibration was performed in three mutually perpendicular directions, with each direction repeated 12 times using the logarithmic frequency sweep method. Vibration lasted for 90 minutes. The appearance and structure of the battery pack were observed to ensure it was intact and free from leakage or cracking. A battery pack with an intact appearance and no leakage or cracking was considered to have excellent structural stability; conversely, a battery pack with poor structural stability was considered to have poor structural stability.

[0092] 2. Testing methods for the safety of lithium-ion battery packs After fully charging the lithium-ion battery pack, place it on a flat surface. Place a steel column with a diameter of 15.8 mm vertically in the center of the lithium-ion battery pack. Drop a weight of 9.1 kg from a height of 610 mm onto the steel column above the lithium-ion battery pack. Observe whether the battery pack catches fire or explodes. If it catches fire or explodes, the safety performance is considered poor. If it does not catch fire or explode, the safety performance is considered excellent.

[0093] 3. Test method for volume utilization rate of lithium-ion battery packs The volume of a single lithium-ion battery is measured using a measuring tool, and then the overall volume of multiple lithium-ion batteries is obtained based on the number of lithium-ion batteries. The volume of the housing is measured using a measuring tool, and the volume utilization rate of the lithium-ion battery pack is calculated as: overall volume of multiple lithium-ion batteries / volume of housing × 100%.

[0094] Table 1 shows the effects of the radius R mm of the central arc 130 in the battery pack 100, the distance H mm between two adjacent individual cells 120, the length L1 mm of the first outer wall surface 1211 of the individual cell 120 in the first direction X, the length L2 mm of the second outer wall surface 1212 in the second direction Y, and the length L3 mm of the third outer wall surface 1213 in the third direction P on the lithium-ion battery pack.

[0095] Table 1. Parameters and test results of Examples 1-27 and Comparative Examples 1-5

[0096] As shown in Table 1, in Comparative Example 1, the lithium-ion battery is a square battery, and the lithium-ion battery pack did not exhibit the corresponding performance. In Comparative Example 2, the specific parameters of the lithium-ion battery pack exceeded the parameter range in this application, resulting in an excessively small spacing between adjacent lithium-ion batteries, making it impossible to properly install the liquid cooling plate, thus causing the lithium-ion battery pack to be scrapped. In Comparative Example 3, the specific parameters of the lithium-ion battery pack exceeded the parameter range in this application, and the lithium-ion battery pack did not exhibit the corresponding performance. In Comparative Examples 4 and 5, the specific parameters of the lithium-ion batteries in the lithium-ion battery pack exceeded the parameter range in this application, resulting in the electrode components in the lithium-ion batteries being unable to be assembled into the casing after winding, making them unsuitable for the electrode assembly winding process, thus causing the lithium-ion batteries to be scrapped, and consequently, the lithium-ion battery pack to be scrapped. The lithium-ion battery packs in Examples 1 to 27, however, showed a certain degree of improvement in structural stability and volume utilization compared to Comparative Examples 1 to 5.

[0097] Therefore, this application limits the individual battery 120 to be a triangular battery, the radius Rmm of the central arc 130 to be in the range of 12.5mm to 20mm, and the distance Hmm between two adjacent individual batteries 120 to be in the range of 5mm to 8mm, so that the individual batteries 120 are arranged compactly in the housing 110, thereby improving the volume utilization rate of the individual batteries 120 in the battery pack 100, and ultimately improving the energy density and capacity of the battery pack 100; at the same time, by limiting the ratio of the length L1mm of the first outer wall surface 1211 in the first direction X to the length L2mm of the second outer wall surface 1212 in the second direction Y to be in the range of 0.7 to 1.43, and the ratio of the length L3mm of the third outer wall surface 1213 in the third direction P to the length L2mm of the second outer wall surface 1212 in the third direction Y to the length L1mm of the third outer wall surface 1212 in the third direction P to the length L2mm of the second outer wall surface 1212 in the third direction Y to the length L1mm of the second outer wall surface 1212 in the third direction Y to the length L2mm of the third outer wall surface 1212 in the third direction Y to the length L2 ... The parameters of the length L1mm of the outer wall 1211 in the first direction X are in the range of 0.5 to 0.865, the length L1mm of the first outer wall 1211 in the first direction X is in the range of 70mm to 100mm, the length L2mm of the second outer wall 1212 in the second direction Y is in the range of 70mm to 100mm, and the length L3mm of the third outer wall 1213 in the third direction P is in the range of 70mm to 173mm. This is to improve the volume utilization rate of the individual battery 120 in the housing 110, thereby improving the energy density of the battery pack 100. At the same time, it can make the individual battery 120 fit together tightly after being assembled, improving the overall structural stability of the battery pack 100, thereby improving the safety performance of the battery pack 100.

[0098] Table 2 shows the included angles α between the first outer wall surface 1211 and the second outer wall surface 1212, β between the first outer wall surface 1211 and the third outer wall surface 1213, λ between the second outer wall surface 1212 and the third outer wall surface 1213, and the orthographic projection area S2mm of the explosion-proof valve 124 on the reference plane A in the battery pack 100. 2 The orthographic projection area of ​​end cap 123 on reference plane A is S1mm. 2 The ratio and the angle γ between the first electrode segment 1221 and the second electrode segment 1222 of the electrode assembly 122 affect the lithium-ion battery pack.

[0099] Table 2. Parameters and test results for Examples 1, 23, and 28-40.

[0100] As shown in Table 2, in Example 39, the specific parameters of the lithium-ion battery in the lithium-ion battery pack exceeded the parameter range specified in this application. This resulted in the electrode assembly in the lithium-ion battery being unable to be assembled into the casing after winding, making it unsuitable for the electrode assembly winding process, thus leading to the scrapping of the lithium-ion battery and consequently the scrapping of the lithium-ion battery pack. In Example 40, the specific parameters of the lithium-ion battery in the lithium-ion battery pack exceeded the parameter range specified in this application, and the lithium-ion battery pack did not exhibit the corresponding performance. However, the structural stability, safety, and energy density of the lithium-ion battery packs in Examples 1, 23, and 28-38 showed a certain degree of improvement compared to Examples 39-40.

[0101] Therefore, this application limits the included angle α between the first outer wall surface 1211 and the second outer wall surface 1212 to the range of 60° to 120°, the included angle β between the first outer wall surface 1211 and the third outer wall surface 1213 to the range of 30° to 60°, the included angle λ between the second outer wall surface 1212 and the third outer wall surface 1213 to the range of 30° to 60°, and the orthographic projection area S2mm of the explosion-proof valve 124 on the reference plane A. 2 The orthographic projection area of ​​end cap 123 on reference plane A is S1mm. 2 The ratio is in the range of 0.05 to 0.15, and the included angle γ between the first electrode segment 1221 and the second electrode segment 1222 is in the range of 90° to 180°, so as to improve the volume utilization rate of the individual battery 120 in the housing 110 and ultimately improve the energy density of the battery pack 100; at the same time, it can make the individual battery 120 fit together tightly after being assembled, improve the overall structural stability of the battery pack 100, and thus improve the safety performance of the battery pack 100.

[0102] The above steps are provided only to help understand the method, structure, and core ideas of this application. Those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A battery pack, characterized in that, include: The box body is equipped with a receiving cavity; as well as The battery pack is housed within the receiving cavity; The battery pack comprises multiple individual cells, with adjacent individual cells spaced apart by a distance of H mm. Each individual cell has three intersecting directions: a first direction, a second direction, and a third direction. Each individual cell includes a housing and an electrode assembly housed within the housing. The housing has a first outer wall surface, a second outer wall surface, and a third outer wall surface connected sequentially. Each individual cell has a corner portion. The first, second, and third outer wall surfaces are distributed circumferentially along the individual cell and are connected in pairs through the corner portions to form a closed surface. The length of the first outer wall surface in the first direction is L1 mm, the length of the second outer wall surface in the second direction is L2 mm, and the length of the third outer wall surface in the third direction is L1 mm. The angle is L3mm; satisfying: 5mm≤Hmm≤8mm, 0.7≤L1 / L2≤1.43, 0.5≤L3 / 2L1≤0.865, 70mm≤L1mm≤100mm, 70mm≤L2mm≤100mm, 70mm≤L3mm≤173mm; the first outer wall surface, the second outer wall surface, and the third outer wall surface are arranged at angles to each other, and the included angle formed by at least two of the first outer wall surface, the second outer wall surface, and the third outer wall surface is an acute angle; the included angle between the first outer wall surface and the second outer wall surface is α, the included angle between the first outer wall surface and the third outer wall surface is β, and the included angle between the second outer wall surface and the third outer wall surface is λ; satisfying: 60°≤α≤120°, 30°≤β≤60°, 30°≤λ≤60°; The battery pack has a central arc, and each individual cell in the battery pack has a target corner portion facing the center of the central arc; the central arc is tangent to the target corner portion of each individual cell facing the center of the central arc, and the radius of the central arc is Rmm, satisfying: 12.5mm≤Rmm≤20mm.

2. The battery pack as described in claim 1, characterized in that, The central angle of the central arc is 360°; and / or, the central angle of the central arc is 180°.

3. The battery pack as described in claim 1, characterized in that, The angle between the first outer wall surface and the second outer wall surface is greater than the angle between the first outer wall surface and the third outer wall surface and the angle between the second outer wall surface and the third outer wall surface; The battery pack satisfies at least one of the following conditions: The two first outer wall surfaces of two adjacent individual battery cells are arranged opposite to each other; The two second outer wall surfaces of two adjacent individual cells are arranged opposite to each other; The first outer wall surface and the second outer wall surface of two adjacent individual cells are arranged opposite to each other; The two third outer wall surfaces of two adjacent individual cells are arranged opposite each other.

4. The battery pack as described in claim 1, characterized in that, The length L1mm of the first outer wall surface in the first direction also satisfies: 80mm≤L1mm≤90mm; and / or, The length L2mm of the second outer wall surface in the second direction also satisfies: 80mm≤L2mm≤90mm; and / or, the length L3mm of the third outer wall surface in the third direction also satisfies: 80mm≤L3mm≤155mm.

5. The battery pack as described in claim 1, characterized in that, The included angle α between the first outer wall surface and the second outer wall surface also satisfies: 80°≤α≤100°; and / or, The included angle β between the first outer wall surface and the third outer wall surface also satisfies: 40°≤β≤50°; and / or, The included angle λ between the second outer wall surface and the third outer wall surface also satisfies: 40°≤λ≤50°.

6. The battery pack as described in claim 1, characterized in that, The single cell also has a fourth direction that intersects the first direction, the second direction and the third direction in pairs, and a reference plane perpendicular to the fourth direction; The single-cell battery further includes: an end cap disposed at at least one end of the housing in the fourth direction and connected to the housing; and An explosion-proof valve is installed on the end cap; Wherein, along the fourth direction, the orthographic projection area of ​​the end cap on the reference plane is S1mm. 2 The orthographic projection area of ​​the explosion-proof valve on the reference plane is S²mm. 2 The condition is satisfied that 0.05 ≤ S2 / S1 ≤ 0.

15.

7. The battery pack as described in claim 1, characterized in that, The electrode assembly has a first electrode segment and a second electrode segment connected to each other, and the included angle between the first electrode segment and the second electrode segment is γ, which satisfies: 90°≤γ≤180°.

8. The battery pack as described in claim 7, characterized in that, The included angle γ between the first electrode segment and the second electrode segment also satisfies: 120°≤γ≤150°.

9. An electrical appliance, characterized in that, Includes a battery pack as described in any one of claims 1 to 8, wherein the battery pack serves as a power supply for the electrical device.

Images