Battery cell, battery and electric device

Abstract

A battery cell (10), a battery (100) and an electric device. The battery cell (10) comprises: a housing (2), which has a plurality of housing walls (21) enclosing an accommodating space, wherein among the plurality of housing walls (21), a first weld seam (211) extending in a first direction is formed at least on a first housing wall (212); and a spacer (1), which is disposed on an outer surface of the first housing wall (212), wherein the spacer (1) has outer edges (11) located on inner sides of an outer surface (22) of the first housing wall (212), among the outer edges (11), the outer edge (11) that extends in the first direction and is closest to the first weld seam (211) in a second direction is a first outer edge (111), the distance between the first outer edge (111) and the first weld seam (211) in the second direction is greater than 0 and not more than 5 mm, and the first direction, the second direction and a wall thickness direction of the housing walls (21) are perpendicular to each other in pairs. In this way, the impact of an expansion force generated by the battery cell (10) on the strength of the first weld seam (211) can be reduced on the basis of minimizing the reduction in the area of the spacer (1), thereby lowering the probability of abnormal weld separation of the first weld seam (211) due to strength attenuation, and facilitating directional pressure relief of the battery cell (10) during thermal runaway.

Description

Battery cells, batteries and electrical devices

[0001] Cross-references to related applications

[0002] This disclosure is based on and claims priority to Chinese Patent Application No. 202420865497.2, filed on April 24, 2024, entitled “Battery Cell, Battery and Electrical Device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of battery technology, and in particular to battery cells, batteries and electrical devices. Background Technology

[0004] The application of new energy batteries in daily life and industry is becoming increasingly widespread. For example, new energy vehicles equipped with batteries are already widely used, and batteries are also increasingly being applied in energy storage. In new energy vehicles equipped with batteries, the batteries can provide all or part of the power. In the field of energy storage, batteries can be installed in energy storage boxes or directly on the user side.

[0005] During cycling, individual battery cells may experience thermal runaway. The industry aims to control the directional ejection of materials within the cell during thermal runaway to avoid further risks from undirected ejection. Therefore, reducing the likelihood of undirected ejection remains a subject of ongoing research in the industry.

[0006] Utility Model Content

[0007] To address the aforementioned technical problems, this disclosure provides a battery cell, a battery, and an electrical device, which can reduce the adverse effects of externally applied expansion forces on the weld strength, reduce the probability of accidental weld cracking due to weld fatigue, and thus facilitate directional pressure relief during thermal runaway.

[0008] This disclosure is achieved through the following technical solution.

[0009] A first aspect of this disclosure provides a battery cell, the battery cell comprising: a housing having a plurality of housing walls forming an accommodating space, wherein at least a first weld extending in a first direction is formed on a first housing wall; a spacer disposed on the outer surface of the first housing wall, the spacer having an outer edge located in the plane of the outer surface of the first housing wall, wherein the outer edge extending in the first direction and closest to the first weld in a second direction is a first outer edge, the distance between the first outer edge and the first weld in the second direction is greater than 0 and not more than 5 mm, and the first direction, the second direction and the wall thickness direction of the housing wall are perpendicular to each other.

[0010] In this embodiment, the spacer provided on the outer surface of the battery casing can serve as heat insulation and buffer. By setting the distance between the first outer edge of the spacer and the first weld along the second direction to be greater than 0 and not more than 5 mm, compared with the previous case where the distance between the outer edge of the spacer and the casing weld was not considered, the influence of the expansion force generated by the battery cell on the strength of the first weld can be reduced without reducing the area of ​​the spacer as much as possible. This reduces the probability of abnormal weld opening due to the strength decay of the first weld, thereby reducing the risk of non-directional pressure relief of the battery cell and helping to directional pressure relief during thermal runaway of the battery cell.

[0011] In some embodiments, the distance between the first outer edge and the first weld along the second direction is in the range of 1.5 mm to 5 mm.

[0012] This can further reduce the maximum strain of the first weld, thus more effectively reducing the probability of abnormal weld failure due to strength decay of the first weld, thereby further reducing the risk of non-directional pressure leakage of battery cells.

[0013] In some embodiments, the distance between the first outer edge and the first weld along the second direction is in the range of 2.5 mm to 5 mm.

[0014] This can further reduce the maximum strain of the first weld, thus more effectively reducing the probability of abnormal weld failure due to strength decay of the first weld, thereby further reducing the risk of non-directional pressure leakage of battery cells.

[0015] In some embodiments, the spacer includes a frame and a spacer pad, the frame being disposed around the spacer pad, and the outer edge of the frame closest to the first weld is the first outer edge.

[0016] By surrounding the spacer with a border, two things are achieved: firstly, it provides space for the spacer and the border also acts as a sealant or adhesive barrier, reducing the probability of structural adhesive overflow; secondly, it provides room for the expansion of the battery cells, reducing compression between adjacent cells and improving the cycle performance of the battery cells.

[0017] In some embodiments, the outer edge of the frame further includes a second outer edge, which is parallel to and spaced apart from the first outer edge along a second direction. Along the second direction, the first housing wall includes an edge opposite to the first weld, separated by a spacer, and the distance between the edge and the second outer edge is in the range of 0 to 3 mm.

[0018] By setting the distance along the second direction between the second outer edge and the edge of the adjacent first housing wall in the range of 0 to 3 mm, the distance along the second direction between the first outer edge and the first weld can be increased as much as possible, reducing the adverse effect of expansion force on the strength of the first weld, and suppressing the reduction of the area of ​​the spacer as much as possible. It can even maintain the shape of the original spacer without changing the existing process equipment, simplifying production and reducing production costs.

[0019] In some embodiments, the border includes a first frame and a second frame spaced apart along a second direction. The first frame is elongated and includes a first outer edge, and the second frame is elongated and includes a second outer edge. The width dimension of the first frame along the second direction is different from the width dimension of the second frame along the second direction.

[0020] Therefore, by adjusting the width of the first frame or the second frame, the distance between the first outer edge and the first weld can be kept within a suitable range while suppressing the reduction of the spacer area, thus taking into account the function of the frame, the size of the spacer, and the influence on the strength of the first weld.

[0021] In some embodiments, the first outer edge of the frame is configured such that the middle portion along the first direction is recessed toward the side where the spacer pad is located compared to the two end portions, and the farthest distance between the first outer edge and the first weld along the second direction is greater than 0 and not more than 5 mm.

[0022] Therefore, by locally adjusting the shape of the first outer edge, the distance between the first outer edge and the first weld can be kept within a suitable range while suppressing the reduction of the spacer area, thus taking into account the function of the frame, the size of the spacer, and the influence on the strength of the first weld.

[0023] In some embodiments, the frame includes a first frame and a second frame spaced apart along a second direction. The first frame is configured such that the middle portion along the first direction is recessed toward the side where the spacer pad is located compared to the two end portions. The middle portion of the first frame is elongated and includes a first outer edge. The second frame is elongated and includes a second outer edge.

[0024] Therefore, by locally adjusting the shape of the first frame, the distance between the first outer edge and the first weld can be kept within a suitable range while suppressing the reduction of the spacer area, thus taking into account the function of the frame, the size of the spacer, and the influence on the strength of the first weld.

[0025] In some embodiments, the border includes a first frame and a second frame spaced apart along a second direction, and a third frame and a fourth frame spaced apart along a first direction, the first frame, the second frame, the third frame and the fourth frame forming a ring.

[0026] Therefore, the spacer can be located within the space enclosed by the frame, serving functions such as heat insulation. It also provides space for the expansion of individual battery cells, reducing compression between adjacent cells, improving electrolyte flow within the cells, and enhancing cycle performance. Furthermore, the frame surrounding the spacer provides sealing and shaping, as well as some support.

[0027] In some embodiments, the first housing wall is the housing wall with the largest outer surface area among the plurality of housing walls. This allows for a better mitigation of battery cell expansion.

[0028] In some embodiments, the frame is a stacked structure, which includes at least a first frame layer and a second frame layer stacked along the wall thickness direction, with the first frame layer disposed between the housing and the second frame layer.

[0029] By setting the frame to at least two layers, the frame can not only serve as a support and / or a barrier, but also improve the stability of the spacer structure itself.

[0030] In some embodiments, the first border layer and the second border layer are made of materials with different hardness.

[0031] When the first and second frame layers have different material hardness, the harder frame layer can provide support and act as a barrier, improving the structural stability of the spacer itself; the softer frame layer can absorb the expansion force generated during the cyclic expansion of the battery cells, alleviating the expansion force acting on the battery cells, especially the expansion force acting on the weld area, thus reducing the impact of the expansion force on the weld strength. The coordinated design of the first and second frame layers improves the overall performance of the spacer.

[0032] In some embodiments, the frame is a rubber frame and the spacer is a heat insulation pad.

[0033] The rubber frame not only provides support and seals the sealant but also absorbs the expansion forces generated during the cycle expansion of the battery cells. This further reduces the impact of expansion forces on weld strength and lowers the risk of non-directional pressure leakage from the battery cells. The spacers are heat-insulating pads, providing insulation and reducing the risk of non-directional pressure leakage from the battery cells, thus improving their cycle performance.

[0034] A second aspect of this disclosure provides a battery comprising a housing and a plurality of battery cells provided in the first aspect of this disclosure housed within the housing. The battery cells are arranged in a manner such that, along the arrangement direction of the battery cells, a first housing wall of one battery cell faces a second housing wall of an adjacent battery cell, and a spacer is located at least between the facing first and second housing walls.

[0035] Because there are spacers between adjacent battery cells in this embodiment, the degree of compression caused by expansion between battery cells can be buffered, and the probability of abnormal weld opening due to strength decay can be reduced, thereby reducing the risk of non-directional pressure relief and battery short circuit, and helping to directional pressure relief in case of thermal runaway.

[0036] A third aspect of this disclosure provides an electrical device, including a battery cell provided in the first aspect of this disclosure or a battery provided in the second aspect of this disclosure, wherein the battery cell is capable of storing electrical energy and providing electrical energy.

[0037] Because the electrical device uses the battery cells or batteries as described above, the impact of expansion force on the weld is reduced, which helps to directionally release pressure in the event of battery thermal runaway and improves the reliability of the electrical device.

[0038] The beneficial effects of the embodiments disclosed herein include: reducing the adverse effects of the expansion force applied to the spacer during the cyclic expansion of the battery cell on the weld strength, reducing the probability of accidental weld cracking due to weld fatigue, thereby facilitating directional pressure relief during thermal runaway. Attached Figure Description

[0039] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0040] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this disclosure;

[0041] Figure 2 is a schematic diagram of the structure of an energy storage device provided in some embodiments of this disclosure;

[0042] Figure 3 is a three-dimensional exploded view of a battery provided in some embodiments of this disclosure;

[0043] Figure 4 is a three-dimensional exploded view of a battery cell provided in some embodiments of this disclosure;

[0044] Figure 5 is a front view of a battery cell provided in some embodiments of this disclosure;

[0045] Figure 6 is a schematic diagram of expansion force analysis provided in some embodiments of this disclosure;

[0046] Figure 7 is a front view of a battery cell provided in some other embodiments of this disclosure;

[0047] Figure 8 is a perspective view of a partial structure of a battery cell provided in some other embodiments of this disclosure.

[0048] Explanation of reference numerals in the attached figures

[0049] 1000 Vehicle; 2000 Energy Storage Device; 100 Battery; 200 Controller; 300 Motor; 400 Electrical Compartment; 10 Battery Cells; 20 Housing; 1 Spacer; 11 Outer Edge; 111 First Outer Edge; 112 Second Outer Edge; 113 Third Outer Edge; 114 Fourth Outer Edge; 12 Frame; 121 First Frame Layer; 1211 First Frame; 1212 Second Frame; 1213 Third Frame; 1214 Fourth Frame; 122 Second Frame Layer; 13 Spacer; 2 Housing; 21 Housing Wall; 212 First Housing Wall; 211 First Weld; 22 Outer Surface; 221 Edge; 23 Housing Body; 24 End Cap; 3 Electrode Assembly; 31 Tab; 4 Terminal Post; X First Direction; Y Second Direction; Z Wall Thickness Direction. Detailed Implementation

[0050] The embodiments of the technical solutions disclosed herein will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solutions disclosed herein and are therefore intended to limit the scope of protection of this disclosure.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure; the terms “comprising” and “having” and any variations thereof in this disclosure are intended to cover non-exclusive inclusion.

[0052] In the description of the embodiments of this disclosure, technical terms such as "first," "second," "third," and "fourth" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "multiple" means two or more, unless otherwise explicitly defined.

[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0054] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0055] In the description of the embodiments of this disclosure, the technical terms "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated, or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0056] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, the technical term "connection" and other such terms should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it 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 the embodiments of this disclosure according to the specific circumstances.

[0057] The embodiments of this disclosure will now be described in detail.

[0058] The application of new energy batteries in daily life and industry is becoming increasingly widespread. For example, new energy vehicles equipped with batteries are already widely used, and batteries are also increasingly being applied in energy storage. In new energy vehicles equipped with batteries, the batteries can provide all or part of the power. In the field of energy storage, batteries can be installed in energy storage boxes or directly on the user side.

[0059] During cyclic operation, battery cells may experience thermal runaway. In the event of thermal runaway, the increased pressure and temperature within the cell's casing can cause its contents to erupt outwards. If this ejected material spreads to surrounding cells or other components, it can lead to further adverse conditions. The industry aims to control the directional ejection of materials from battery cells during thermal runaway to avoid the further risks associated with undirected ejection. Therefore, reducing the likelihood of undirected ejection remains a subject of ongoing research in the industry.

[0060] In a battery cell, the cell casing is formed by welding several casing walls together. In this case, weld seams may exist at the edges of the casing walls. In some cases, the weld seams may become weak due to fatigue, and in the event of thermal runaway in the battery cell, the weld seams may become weak points and crack outwards, causing the battery cell to fail to depressurize or erupt in the intended direction as originally designed (e.g., with a pressure relief mechanism).

[0061] In addition, individual battery cells expand and generate heat during cyclic use. To prevent thermal interference between closely spaced battery cells, spacers are sometimes placed on the outer surface (e.g., the large surface) of the battery cells. These spacers include heat-insulating pads that provide insulation while mitigating the pressure between adjacent cells due to expansion. Furthermore, a rubber frame is placed around the heat-insulating pads to provide sealing and shaping, as well as some support when adjacent battery cells are compressed due to expansion.

[0062] In related technologies, spacers are typically used to cover the entire surface of a housing wall, with the outer edge of the rubber frame of the spacer possibly located at the weld. Studies have found that, under conditions where, for example, the compressive force generated by the expansion of adjacent battery cells repeatedly acts on the rubber frame, the rubber frame repeatedly compresses the weld, which may lead to a decrease in the fatigue strength of the weld. Consequently, in the event of thermal runaway of a battery cell, the weld may unexpectedly crack without directional pressure relief.

[0063] In view of the above, it is desirable to provide a solution that can reduce the adverse effects of spacers on weld strength, thereby reducing the probability of non-directional pressure leakage. Research results show that by setting the distance between the weld and the outer edge of the spacer within an appropriate range, it helps to weaken the influence of the expansion force generated during the cyclic expansion of the battery cell on the weld strength via the spacer. By setting the distance between the weld and the edge of the spacer, the probability of weld breakage is reduced, lowering the risk of non-directional pressure leakage from the battery cell, thus helping to facilitate directional ejection when the battery cell experiences thermal runaway.

[0064] Based on this design concept, the inventors of this disclosure have designed a battery cell, which includes: a housing having a plurality of housing walls forming an accommodating space, wherein at least a first weld extending in a first direction is formed on the first housing wall; a spacer disposed on the outer surface of the first housing wall, the spacer having an outer edge located in the plane of the outer surface of the first housing wall, wherein the outer edge extending in the first direction and closest to the first weld in the second direction is the first outer edge, and the distance between the first outer edge and the first weld in the second direction is greater than 0 and not more than 5 mm, wherein the first direction, the second direction and the wall thickness direction of the housing wall are perpendicular to each other.

[0065] Setting spacers on the surface of the battery casing can serve as heat insulation and buffering. By setting the distance between the first outer edge of the spacer and the first weld along the second direction to be greater than 0 and not more than 5 mm, compared with the previous case where the distance between the outer edge of the spacer and the casing weld was not considered, the influence of the expansion force generated by the battery cell on the strength of the first weld can be reduced without reducing the area of ​​the spacer as much as possible. This reduces the probability of abnormal weld opening due to the strength decay of the first weld, thereby reducing the risk of non-directional pressure relief of the battery cell and helping to directional pressure relief during thermal runaway of the battery cell.

[0066] The battery cells provided in this disclosure can also be grouped together to be used as batteries. Batteries include battery modules or battery packs. Batteries can also be used, but are not limited to, in electrical devices such as energy storage power systems, vehicles, ships, or aircraft.

[0067] This disclosure provides an electrical device comprising the aforementioned battery cell or battery, wherein the battery cell or battery provides electrical energy to the electrical device. The electrical device may include, but is not limited to, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. Electric toys may include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys; spacecraft may include airplanes, rockets, space shuttles, and spacecraft.

[0068] The electrical device in this embodiment of the disclosure also includes an energy storage device, in which a battery comprising multiple individual cells can store electrical energy and provide electrical energy. The energy storage device may include, but is not limited to, energy storage containers, energy storage cabinets, etc.

[0069] In the following embodiments, for ease of explanation, the electrical device of some embodiments of this disclosure will be described using a vehicle 1000 as an example. The description is as follows with reference to the accompanying drawings.

[0070] In some embodiments of this disclosure, for ease of explanation, a first direction and a second direction are defined, which are directions that intersect each other. Here, intersecting each other includes perpendicularly intersecting each other. For ease of understanding of the embodiments of this disclosure, in the embodiments shown in Figures 1 to 8, an example is given where the first direction, the second direction, and the wall thickness direction of the housing wall with the spacer are perpendicularly intersecting each other. However, those skilled in the art should understand that the embodiments of this disclosure are not limited to the case where these three directions intersect each other perpendicularly. For ease of explanation, as shown by the arrows in Figures 4 to 8, the direction where arrow X is located is the first direction, the direction where arrow Y is located is the second direction, and the direction where arrow Z is located is the wall thickness direction.

[0071] Figure 1 is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this disclosure. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. As shown in Figure 1, a battery 100 is disposed inside the vehicle 1000. The battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0072] In some embodiments of this disclosure, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0073] Figure 2 is a schematic diagram of the structure of an energy storage device 2000 provided in some embodiments of this disclosure. The energy storage device 2000 can be an energy storage container or an energy storage cabinet, etc. The energy storage device 2000 can also be used as an electrical device. As shown in Figure 2, the energy storage device 2000 can include a battery 100 arranged in a battery compartment and an electrical compartment 400. The electrical compartment 400 can, for example, house an electrical control box, for controlling the charging and discharging of the battery 100, monitoring the operating status of the battery 100, etc., for example, for monitoring parameters such as ambient temperature and humidity.

[0074] Figure 3 is an exploded perspective view of a battery 100 provided in some embodiments of the present disclosure. As shown in Figure 3, the battery 100 includes a housing 20 that encloses a receiving space and at least one battery cell 10. The housing 20 includes, for example, a lower housing and an upper housing that can be joined together to form the receiving space, and the battery cell 10 is arranged in the receiving space.

[0075] In battery 100, there can be one or more battery cells 10 to provide a single physical module with higher voltage and capacity. Multiple battery cells 10 can be connected in series, parallel, or in a hybrid configuration, where some battery cells 10 are connected in series and others in parallel. Multiple battery cells 10 can be directly connected in series, parallel, or in a hybrid configuration, and then the assembly of the multiple battery cells 10 is placed in the receiving space formed by the upper and lower housings. Alternatively, battery 100 can also be composed of multiple battery cells 10 first connected in series, parallel, or in a hybrid configuration to form a battery module, and then multiple battery modules are connected in series, parallel, or in a hybrid configuration to form a whole, which is then housed in the receiving space formed by the upper and lower housings. Battery 100 may also include other structures; for example, battery 100 may also include a busbar component for realizing electrical connections between multiple battery cells 10.

[0076] In this embodiment, the battery cell 10 can be a secondary battery, such as a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and this embodiment is not limited to this. Battery cells 10 are generally classified into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and this embodiment is not limited to this either.

[0077] Figure 4 is an exploded perspective view of a battery cell 10 provided in some embodiments of this disclosure. As shown in Figure 4, the battery cell 10 includes a housing 2 and an electrode assembly 3. The housing 2 is used to encapsulate the electrode assembly 3 and components such as the electrolyte. The housing 2 can be a steel housing, an aluminum housing, a plastic housing (such as a polypropylene housing), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film, etc.

[0078] As an example, the battery cell 10 can be a prismatic battery cell or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This disclosure does not have any particular limitations.

[0079] In some embodiments, as shown in FIG4, the housing 2 includes a housing body 23 and an end cap 24. The housing body 23 has an opening, and the end cap 24 closes the opening to form a sealed space for accommodating the electrode assembly 3. The housing 2 may include a plurality of housing walls 21. In the embodiment shown in FIG4, it includes six housing walls 21. Adjacent housing walls 21 may be integrally connected or connected by means of welding or the like. In the case of welding connection, a weld is formed at the junction of the connected housing walls 21.

[0080] In some embodiments, as shown in FIG4, at least one pole post 4 is provided on the housing 2, and the pole post 4 is electrically connected to the tab 31. The pole post 4 can be directly connected to the tab 31, or it can be indirectly connected to the tab 31 through an adapter. The pole post 4 can be provided on the end cap 24, or it can be provided on the housing body 23.

[0081] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to Figures 5 to 8.

[0082] Figure 5 is a front view of a battery cell 10 provided in some embodiments of the present disclosure; Figure 6 is a schematic diagram of expansion force analysis provided in some embodiments of the present disclosure; Figure 7 is a front view of a battery cell provided in other embodiments of the present disclosure; Figure 8 is a three-dimensional schematic diagram of a portion of the structure of a battery cell provided in yet another embodiment of the present disclosure.

[0083] In a first aspect, embodiments of this disclosure provide a battery cell 10. As shown in Figures 4 and 5, the battery cell 10 includes: a housing 2 having a plurality of housing walls 21 forming an accommodating space, wherein at least one of the housing walls 21 has a first weld 211 extending along a first direction X formed on at least the first housing wall 212; a spacer 1 disposed on the outer surface 22 of the first housing wall 212, the spacer 1 having an outer edge 11 located in the plane of the outer surface 22 of the first housing wall 212, wherein the outer edge 11 extending along the first direction X and being closest to the first weld 211 along the second direction Y is the first outer edge 111, the distance L1 between the first outer edge 111 and the first weld 211 along the second direction Y is greater than 0 and not more than 5 mm, and the first direction X, the second direction Y and the wall thickness direction Z of the housing wall 21 are perpendicular to each other.

[0084] As shown in Figure 4, the battery cell 10 includes a housing 2, which has multiple housing walls 21 forming an accommodating space. A first weld 211 is formed on at least one housing wall 21, where adjacent housing walls 21 are connected. In the embodiment shown in Figure 4, the weld between the first housing wall 212 and its adjacent bottom housing wall is used as an example for explanation. The bottom edge of the first housing wall 212 is connected to the bottom housing wall (the housing wall opposite to the end cap 24 along the second direction Y) by welding, forming a weld at the welding position. For ease of explanation, this weld is referred to as the first weld 211. Here, for ease of explanation, one of the housing walls 21 is referred to as the first housing wall 212, although the first housing wall 212 can be any one of the multiple housing walls 21 of the housing. In the embodiments shown in Figures 4 and 5, the first weld 211 extends along the first direction X. In reality, the weld of the first weld 211, etc., usually has a certain width, but for the sake of illustration and explanation, the first weld 211 is represented as a line in the figures.

[0085] Optionally, there can be one, two, three, four, etc., battery cells 10. When there are multiple battery cells 10, they are connected in series, parallel, or mixed via a busbar. The multiple battery cells 10 are arranged along an arrangement direction. In some embodiments, they can be arranged along the wall thickness direction Z of the first housing wall 212, and the first housing walls 212 of each battery cell 10 face the same direction. Two housing walls that are adjacent to and face each other along the wall thickness direction Z can be the first housing wall 212 of one battery cell 10 and the second housing wall of another battery cell 10.

[0086] As shown in Figure 5, a spacer 1 is provided on the outer surface 22 of the first housing wall 212. The spacer 1 has an outer edge 11, which can be the circumferential outer contour of the spacer 1. The outer edge 11 of the spacer 1 is located in the plane of the outer surface 22 of the first housing wall 212. The outer edge 11 includes a first outer edge 111, which extends along the first direction X. Of course, the outer edge 11 also includes other outer edges connected to the first outer edge 111. Here, the first outer edge 111 is used as an example for explanation. Further, the case where the first outer edge 111 is closest to the first weld 211 along the second direction Y is used as an example for explanation. It is understandable that the first weld 211 may not be a weld located on the first shell wall 212, but may be a weld located on other shell walls 21; the first weld 211 may not be a weld near the bottom of the first shell wall 212, but may be other welds in the first shell wall 212; the first outer edge 111 may not be closest to the first weld 211, but may be closest to other welds.

[0087] In some embodiments, along the second direction Y, the distance L1 between the first outer edge 111 and the first weld 211 is greater than 0 and does not exceed 5 mm. The first direction X, the second direction Y, and the wall thickness direction Z of the housing wall 21 are all perpendicular to each other. The wall thickness direction Z is parallel to the direction perpendicular to the first housing wall 212. For ease of explanation, as shown by the arrows in Figures 5 to 8, the direction pointed to by arrow X is the first direction X, the direction pointed to by arrow Y is the second direction Y, and the square pointed to by arrow Z is the wall thickness direction Z.

[0088] Optionally, the spacer 1 can be rectangular, pentagonal, or irregular in shape. As shown in Figure 5, the example of a rectangular spacer 1 will be used for illustration.

[0089] Optionally, the spacer 1 may have functions such as adhesive blocking, heat insulation, or heat conduction. In a specific embodiment, the spacer 1 includes a spacer pad 13 and a frame 12. The spacer pad 13 is a sheet-like component with heat insulation and insulating properties, serving as heat insulation and buffering functions; the frame 12 is located around the spacer pad 13, serving as a sealing and shaping function. Optionally, the spacer pad 13 may be polyurethane foam, and the frame 12 may be a rubber frame.

[0090] In one specific embodiment, the shape of the spacer 1 matches the shape of the large surface of the battery cell 10. When the large surface of the battery cell 10 is rectangular, the corresponding spacer 1 can also be processed into a rectangle. Of course, the spacer 1 is not limited to being disposed on the large surface, but can also be disposed on other surfaces, or even on multiple surfaces; the shape of the spacer 1 is also not limited to being similar to the shape of the disposed surface, and can also be a surface of other shapes as long as it can function.

[0091] Optionally, for ease of description, the following embodiments are illustrated using the orientation shown in Figure 5. When the first weld 211 is located on the upper part of the outer surface 22, the first outer edge 111 is the upper edge of the outer edge 11; when the first weld 211 is located on the lower part of the outer surface 22, the first outer edge 111 is the lower edge of the outer edge 11; when the first weld 211 is located on the left part of the outer surface 22, the first outer edge 111 is the left edge of the outer edge 11; when the first weld 211 is located on the right part of the outer surface 22, the first outer edge 111 is the right edge of the outer edge 11. The following embodiments use the first weld 211 as an example, with the first weld 211 located on the lower part of the outer surface 22.

[0092] The distance L1 between the first outer edge 111 and the first weld 211 is greater than 0 and does not exceed 5 mm.

[0093] Optionally, the distance L1 can be 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm. Of course, other distances within the above range can also be used.

[0094] In some specific embodiments, for ease of description, the orientation shown in Figure 5 is used as an example. The spacer 1 has a rectangular frame 12 with a hollow center. The frame 12 includes a first frame 1211 and a second frame 1212 located on the top and bottom sides, and a third frame 1213 and a fourth frame 1214 located on the left and right sides, respectively. These frames have a certain width. The width of the frames can be set according to the desired size of the spacer pad 13, the spacing between the outer edge 11 of the frame 12 and the periphery of the housing wall 21, etc.

[0095] To further investigate the influence of the distance L1 between the first outer edge 111 and the first weld 211 on the weld strength, the following experiment was conducted.

[0096] A spacer 1 is bonded to the first housing wall 212 of the battery cell. The spacer 1 includes a spacer pad 13 and a rubber frame 12. In the frame 12, the widths d1 and d2 of the first frame 1211 and the second frame 1212 along the second direction Y are both 6 mm, and the widths d3 and d4 of the third frame 1213 and the fourth frame 1214 along the first direction X are both 9 mm. The study of the maximum strain at the weld location caused by the external force (simulating the repeated extrusion force applied during the expansion of a single battery cell) when the distance L1 between the first outer edge 111 and the first weld 211 is 0 mm, 1.5 mm, 2.5 mm, and 5 mm shows that when the distance L1 is 0 mm, the strain at the first weld 211 is 4.02%; when the distance L1 is 1.5 mm, the strain at the first weld 211 is 3.56%; when the distance L1 is 2.5 mm, the strain at the first weld 211 is 3.20%; and when the distance L1 is 5 mm, the strain at the first weld 211 is 3.06%.

[0097] The above research results indicate that, along the second direction Y, when the distance L1 between the first outer edge 111 and the first weld 211 increases, the strain at the first weld 211 decreases. However, since the increase in distance L1 may lead to a reduction in the area of ​​the spacer 1, especially the spacer pad 13 in the spacer 1, it may have a negative impact on the heat insulation and buffering effect when the battery cell 10 expands. Therefore, it is necessary to balance the fatigue strength of the first weld 211 and the area of ​​the spacer pad 13.

[0098] Furthermore, the possible reasons for the decrease in strain at the first weld 211 as the distance L1 increases are analyzed. As shown in Figure 6, during the cyclic expansion of the battery cell 10, the expansion force F generated by adjacent battery cells 10 is applied to the frame of the spacer 1. The frame closest to the weld has a greater impact on the strength of the weld. The expansion force F applied to the first frame 1211 exerts a torque M on the first weld 211. Under the action of the torque M, strain is generated at the first weld 211, and this repeated process affects the strength of the first weld 211. Without reducing the thickness of the spacer 1, when the distance L1 is increased, the rotation angle θ that the external force can rotate through decreases, the work done by the expansion force F in compressing the first frame 1211 decreases, and thus the influence on the strength of the first weld 211 decreases.

[0099] Therefore, the spacer 1 on the outer surface 22 of the battery casing 2 can serve as heat insulation and buffer. By setting the distance L1 between the first outer edge 111 of the spacer 1 and the first weld 211 along the second direction Y to be greater than 0 and not more than 5 mm, compared with the previous case where the distance between the outer edge 11 of the spacer 1 and the weld of the casing 2 was not considered, the influence of the expansion force F generated by the battery cell 10 on the strength of the first weld 211 can be reduced without reducing the area of ​​the spacer 1 as much as possible. This reduces the probability of abnormal weld opening of the first weld 211 due to its strength decay, thereby reducing the risk of non-directional pressure relief of the battery cell 10 and helping to directional pressure relief when the battery cell 10 experiences thermal runaway.

[0100] In some embodiments, the distance L1 between the first outer edge 111 and the first weld 211 along the second direction Y is in the range of 1.5 mm to 5 mm.

[0101] As shown in Figure 5, along the second direction Y, the distance L1 between the first outer edge 111 and the first weld 211 is in the range of 1.5mm to 5mm.

[0102] Optionally, the distance L1 can be 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm. Of course, other distances L1 within the above range can also be used.

[0103] This can further reduce the maximum strain of the first weld 211, thus more effectively reducing the probability of abnormal weld failure due to strength decay of the first weld 211, thereby further reducing the risk of non-directional pressure leakage of the battery cell 10.

[0104] In some embodiments, the distance L1 between the first outer edge 111 and the first weld 211 along the second direction Y is in the range of 2.5 mm to 5 mm.

[0105] As shown in Figure 5, along the second direction Y, the distance L1 between the first outer edge 111 and the first weld 211 is in the range of 2.5mm to 5mm.

[0106] Optionally, the distance L1 can be 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm. Of course, other distances L1 within the above range can also be used.

[0107] This can further reduce the maximum strain of the first weld 211, thus more effectively reducing the probability of abnormal weld failure due to strength decay of the first weld 211, thereby further reducing the risk of non-directional pressure leakage of the battery cell 10.

[0108] In some embodiments, the spacer 1 includes a frame 12 and a spacer pad 13, the frame 12 is disposed around the spacer pad 13, and the outer edge 11 of the outer edge 11 of the frame 12 that is closest to the first weld 211 is the first outer edge 111.

[0109] As shown in Figure 5, the spacer 1 includes a frame 12 and a spacer pad 13. The frame 12 is arranged around the spacer pad 13. The frame 12 has an outer edge 11, and the outer edge 11 closest to the first weld 211 is the first outer edge 111.

[0110] Optionally, the spacer pad 13 can be in sheet form.

[0111] Optionally, the border 12 can be a hollow frame structure, the spacer 13 can occupy the entire hollow area, or the spacer 13 can occupy a part of the hollow area, and the hollow area can be a rectangle, a circle, or an irregular shape, etc.

[0112] In some embodiments, the thickness of the frame 12 along the wall thickness direction Z is in the range of 1 mm to 5 mm. Optionally, the thickness of the frame 12 along the wall thickness direction Z can be 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm, etc., or of course, other thicknesses within the above range. In addition, without departing from the spirit of this disclosure, thicknesses outside the above range may also be used.

[0113] By surrounding the spacer 13 with the frame 12, on the one hand, it not only provides corresponding placement space for the spacer 13, but the frame 12 can also play a role in sealing and shaping or blocking adhesive, reducing the probability of structural adhesive overflow. On the other hand, it can also provide room for the expansion of the battery cell 10, reduce the compression between adjacent battery cells 10, and improve the cycle performance of the battery cell 10.

[0114] In some embodiments, the outer edge 11 further includes a second outer edge 112, which is parallel to the first outer edge 111 and spaced apart from the first outer edge 111 along a second direction Y. Along the second direction Y, the first housing wall 212 includes an edge 221 that is opposite to the first weld 211 through a spacer 1, and the distance L2 between the edge 221 and the second outer edge 112 is in the range of 0 to 3 mm.

[0115] As shown in Figure 5, the outer edge 11 also includes a second outer edge 112, which is parallel to the first outer edge 111. Along the second direction Y, the second outer edge 112 and the first outer edge 111 are spaced apart. The first housing wall 212 includes an edge 221 (the upper edge in the specific example shown in Figure 5). Along the second direction Y, the first weld 211 and the edge 221 are located on both sides of the spacer 1. Along the second direction Y, the distance L2 between the edge 221 and the second outer edge 112 is in the range of 0 to 3 mm.

[0116] Optionally, the distance L2 can be 0mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm or 3mm, or other distances L2 within the above range.

[0117] By setting the distance L2 between the second outer edge 112 and the edge 221 of the adjacent first housing wall 21 along the second direction Y to a range of 0 to 3 mm, the distance L1 between the first outer edge 111 and the first weld 211 along the second direction Y can be increased as much as possible, reducing the adverse effect of the expansion force F on the strength of the first weld 211, and suppressing the reduction of the area of ​​the spacer 13 as much as possible. It can even maintain the shape of the original spacer 13 without changing the existing process equipment, simplifying production and reducing production costs.

[0118] In some embodiments, the border 12 includes a first frame 1211 and a second frame 1212 spaced apart along the second direction Y. The first frame 1211 is elongated and includes a first outer edge 111, and the second frame 1212 is elongated and includes a second outer edge 112. The width dimension of the first frame 1211 along the second direction Y is different from the width dimension of the second frame 1212 along the second direction Y.

[0119] As shown in Figure 5, the frame 12 has a first frame 1211 and a second frame 1212 extending along the first direction Y and forming a strip. The first frame 1211 and the second frame 1212 are spaced apart along the second direction Y. The first frame 1211 includes a first outer edge 111, and the second frame 1212 includes a second outer edge 112. Along the second direction Y, the width of the first frame 1211 is different from the width of the second frame 1212, that is, along the second direction Y, the width d2 of the first frame 1211 is different from the width d1 of the second frame 1212.

[0120] Optionally, along the second direction Y, the width d1 of the first frame 1211 can be greater than the width d2 of the second frame 1212; the width d1 of the first frame 1211 can also be less than the width d2 of the second frame 1212.

[0121] Optionally, when d2 is 5mm, d1 can be 5mm, 6mm, 7mm, 8mm, or 9mm, 10mm, etc.; when d2 is 6mm, d1 can be 5mm, 6mm, 7mm, 8mm, or 9mm, 10mm, etc.; when d2 is 8mm, d1 can be 5mm, 6mm, 7mm, 8mm, or 9mm, 10mm, etc.; when d2 is 10mm, d1 can be 5mm, 6mm, 7mm, 8mm, or 9mm, 10mm, etc. Of course, widths d1 and d2 can also be other reasonable values ​​based on the area of ​​the spacer pad 13.

[0122] Optionally, the first frame 1211 can be designed to be wider than the second frame 1212, thereby enabling the area in the frame 12 for placing the spacer pad 13 to have a larger area without reducing the supporting effect of the first frame 1211 on the expansion force of the adjacent battery cell 10.

[0123] Optionally, the first frame 1211 can be designed to be narrower than the second frame 1212. Thus, by adjusting the width of the first frame 1211, the distance L1 between the first outer edge 111 and the first weld 211 can be controlled.

[0124] Therefore, by adjusting the width of the first frame 1211 or the second frame 1212, the distance L1 between the first outer edge 111 and the first weld 211 can be kept within a suitable range while suppressing the reduction of the area of ​​the spacer 13. This balances the function of the frame 12, the size of the spacer 13, and the influence on the strength of the first weld 211.

[0125] In some embodiments, the first outer edge 111 of the frame 12 is configured such that the middle portion along the first direction X is recessed toward the side where the spacer pad 13 is located compared to the two end portions, and the farthest distance L1 between the first outer edge 111 and the first weld 211 along the second direction Y is greater than 0 and does not exceed 5 mm.

[0126] As shown in Figure 7, the middle part of the first outer edge 111 in the frame 12 is recessed towards the side where the spacer pad 13 is located compared to the two ends. The farthest distance L1 between the first outer edge 111 and the first weld 211 along the second direction Y is greater than 0 and does not exceed 5mm. The farthest distance L1 refers to the distance between the area of ​​the first outer edge 111 furthest from the first weld 211 and the first weld 211 along the second direction Y.

[0127] As shown in Figure 7, the farthest distance L1 refers to the distance between the middle portion of the first outer edge 111 (the lower edge in Figure 7) and the first weld 211 along the second direction Y. Figure 7 exemplarily shows that the middle portion of the first outer edge 111 is straight, but it can also be other shapes, such as an arc.

[0128] Therefore, by locally adjusting the shape of the first outer edge 111, the distance L1 between the first outer edge 111 and the first weld 211 can be kept within a suitable range while suppressing the reduction of the area of ​​the spacer 13. This can take into account the function of the frame 12, the size of the spacer 13, and the influence on the strength of the first weld 211.

[0129] In some embodiments, the frame 12 includes a first frame 1211 and a second frame 1212 spaced apart along a second direction Y. The first frame 1211 is configured such that the middle portion along the first direction X is recessed toward the side where the spacer pad 13 is located compared to the two end portions. The middle portion of the first frame 1211 is elongated and includes a first outer edge 111. The second frame 1212 is elongated and includes a second outer edge 112.

[0130] As shown in Figure 7, the frame 12 includes a first frame 1211 and a second frame 1212. Along the second direction Y, the first frame 1211 and the second frame 1212 are spaced apart. Along the first direction X, the middle part of the first frame 1211 is recessed towards the side where the spacer pad 13 is located compared to the two end parts. The middle part is configured as a strip and includes a first outer edge 111. The second frame 1212 is configured as a strip and includes a second outer edge 112.

[0131] Optionally, the middle portion of the first outer edge 111 can be recessed toward the side where the spacer pad 13 is located by forming a bend or curve at the end where the first outer edge 111 connects to the third frame 1213 and the fourth frame 1214. In the specific example shown in FIG7, the end of the first outer edge 111 has an angle of approximately 45 degrees with the third frame 1213 and the fourth frame 1214. Of course, this is just an example.

[0132] Therefore, by locally adjusting the shape of the first frame 1211, the distance L1 between the first outer edge 111 and the first weld 211 can be kept within a suitable range while suppressing the reduction of the area of ​​the spacer 13. This can take into account the function of the frame 12, the size of the spacer 13, and the influence on the strength of the first weld 211.

[0133] In some embodiments, as shown in FIG5, FIG7 and FIG8, the border 12 includes a first frame 1211 and a second frame 1212 spaced apart along a second direction Y, and a third frame 1213 and a fourth frame 1214 spaced apart along a first direction X, wherein the first frame 1211, the second frame 1212, the third frame 1213 and the fourth frame 1214 form a ring.

[0134] Optionally, the third frame 1213 or the fourth frame 1214 can be a long strip, a rectangle, or other irregular shapes.

[0135] Therefore, the spacer 13 can be located within the space enclosed by the frame, serving functions such as heat insulation. It also provides space for the expansion of the battery cell 10, reducing compression between adjacent battery cells 10, improving electrolyte flow within the battery cell 10, and enhancing the cycle performance of the battery cell 10. In addition, the frame surrounding the spacer 13 can provide sealing and shaping functions as well as some support.

[0136] In some embodiments, the first housing wall 212 is the housing wall 21 with the largest area of ​​its outer surface 22 among the plurality of housing walls 21.

[0137] As shown in Figure 4, among the multiple shell walls 21, the shell wall 21 with the largest outer surface 22 area includes a first shell wall 212 and a shell wall (not shown) opposite to the first shell wall 212 along the wall thickness direction Z. In some embodiments, the spacer 1 is formed on the first shell wall, which can be the first shell wall 212 shown in Figure 4, or it can be a shell wall opposite to the first shell wall 212 along the wall thickness direction Z. Here, "first" is only for descriptive purposes and does not limit it to one of the shell walls with the largest area. In another embodiment, the spacer 1 is formed on two shell walls opposite to each other along the wall thickness direction Z.

[0138] Of course, spacers 1 can also be formed on other shell walls.

[0139] Therefore, it can better alleviate the expansion of the battery cell 10.

[0140] In some embodiments, as shown in FIG8, the frame 12 is a stacked structure, which includes at least a first frame layer 121 and a second frame layer 122 stacked along the wall thickness direction Z, with the first frame layer 121 disposed between the housing 2 and the second frame layer 122.

[0141] As shown in Figure 8, the frame 12 is a stacked structure. The stacked structure includes at least a first frame layer 121 and a second frame layer 122 stacked along the wall thickness direction Z. The first frame layer 121 is located between the shell 2 and the second frame layer 122, that is, along the direction perpendicular to the plane formed by the first direction X and the second direction Y, the shell 2, the first frame layer 121 and the second frame layer 122 are connected and arranged in sequence.

[0142] Optionally, the frame 12 can be two, three, or four layers stacked along the wall thickness direction Z, and this embodiment does not limit this.

[0143] By setting the frame 12 to at least two layers, the frame 12 can not only serve as a support and / or a barrier, but also improve the stability of the spacer 1 itself.

[0144] In some embodiments, the materials of the first border layer 121 and the second border layer 122 have different hardness.

[0145] As shown in Figure 8, the hardness of the materials of the first border layer 121 and the second border layer 122 can also be different.

[0146] The first frame layer 121 can be made of a material with relatively low elasticity, while the second frame layer 122 can be made of a material with relatively high elasticity. In some embodiments, the hardness of the first frame layer 121 can be greater than that of the second frame layer 122. For example, the first frame layer 121 can be made of rubber, resin, etc., while the second frame layer 122 can be made of rubber, silicone, polyurethane foam, etc.

[0147] When the materials of the first frame layer 121 and the second frame layer 122 have different hardness, the harder frame layer 12 can provide support, thereby improving the structural stability of the spacer 1 itself; the softer frame layer 12 can absorb the expansion force F generated during the cyclic expansion of the battery cell 10, reducing the expansion force F acting on the battery cell 10, especially reducing the expansion force F acting on the first weld 211 region, thus weakening the impact of the expansion force F on the strength of the first weld. The coordinated design of the first frame layer 121 and the second frame layer 122 improves the overall performance of the spacer 1.

[0148] In some embodiments, the frame 12 is made of rubber, and the spacer 13 is a heat insulation pad.

[0149] As shown in Figure 5, the frame 12 is made of rubber, and the spacer 13 is a heat insulation pad. The heat insulation pad is used for heat insulation between battery cells 10.

[0150] The frame 12 is made of rubber, which not only provides support but also absorbs the expansion force F generated during the cyclic expansion of the battery cell 10. This further reduces the impact of the expansion force F on the strength of the first weld 211 and further reduces the risk of non-directional pressure leakage of the battery cell 10. The spacer 13 is a heat insulation pad, which enables the spacer 1 to provide heat insulation, reducing the risk of non-directional pressure leakage of the battery cell 10 and improving the cycle performance of the battery cell 10.

[0151] Secondly, as shown in FIG3, this disclosure provides a battery 100, which includes a housing 20 and a plurality of battery cells 10 as described above housed in the housing 20. The battery cells 10 are arranged in a manner such that, along the arrangement direction of the battery cells 10, the first housing wall 212 of one battery cell 10 faces the second housing wall of another adjacent battery cell 10, and the spacer 1 is located at least between the facing first housing wall 212 and the second housing wall.

[0152] The batteries 100 can be arranged as needed, and spacers 1 can be provided between adjacent battery cells 10 along the arrangement direction. The battery cells 10 can be arranged with their large surfaces facing each other, or with their sides (surfaces other than the large surfaces) facing each other. In the embodiment shown in this disclosure, the battery cells 10 are arranged with their large surfaces facing each other.

[0153] Since there is a spacer 1 between adjacent battery cells 10 in this embodiment, it can buffer the degree of compression caused by expansion between battery cells 10, and reduce the probability of abnormal weld opening due to the weakening of weld strength, thereby reducing the risk of non-directional pressure relief and battery short circuit of battery 100, and helping to directional pressure relief in case of thermal runaway.

[0154] Thirdly, as shown in FIG1, this disclosure provides an electrical device, including a battery cell 10 as described above or a battery 100 as described above, wherein the battery cell 10 is capable of storing electrical energy and providing electrical energy. The electrical device also includes an energy storage device.

[0155] Since the electrical device uses the battery cell 10 as described above or the battery 100 as described above, the influence of the expansion force F on the weld is reduced, which helps to directionally release pressure when the battery 100 thermally runs away, and improves the reliability of the electrical device.

[0156] The following describes a specific embodiment of this disclosure.

[0157] As shown in Figures 5 to 8, the battery cell 10 includes a housing 2, which has multiple housing walls 21 forming an accommodating space. At least on the first housing wall 212, a first weld 211 extending along a first direction X is formed. The first weld 211 is located at the bottom of the first housing wall 212. A spacer 1 is connected in-plane to the outer surface 22 of the first housing wall 212. The outer edge 11 of the spacer 1 is located within the outer surface 22. The spacer 1 consists of a heat-insulating pad and a rubber frame (border 12) surrounding the heat-insulating pad. The heat-insulating pad is a sheet-like component with heat insulation and insulating functions, providing both heat insulation and cushioning. The rubber frame 12 is generally rectangular. The spacer 1 is located between adjacent battery cells 10.

[0158] During the cyclic expansion of the battery cell 10, the expansion force F applied to the rubber frame will exert a torque M on the weld position, which will worsen the weld strength of the battery cell 10. From the perspective of reducing the influence of torque M on weld strength, without reducing the thickness of the rubber frame, the rotation angle θ that the expansion force F can rotate can be reduced by increasing the distance between the weld and the rubber frame, thereby improving the adverse effect of the expansion force F on the weld strength near the rubber frame and thus improving the problem of abnormal weld bursting due to strength decay.

[0159] The lower frame of the rubber frame (shown in Figure 5) is the first frame 1211, and the lower edge of the outer edge 11 (shown in Figure 5) is the first outer edge 111. The distance L1 between the first outer edge 111 and the first weld 211 along the second direction Y is greater than 0 mm and does not exceed 5 mm, with a further distance L1 ranging from 2.5 mm to 5 mm. The setting of distance L1 reduces the influence of the expansion force F generated by the battery cell 10 acting on the first frame 1211 during the cyclic expansion of the battery cell 10 on the strength of the first weld 211. This is because during the cyclic expansion of the battery cell 10, the expansion force F applied to the first frame 1211 will apply a torque M to the position of the first weld 211. The torque M does work on the first weld 211, weakening the strength of the first weld 211. From the perspective of reducing the work W done by the torque M, without reducing the thickness of the heat insulation pad, by limiting the distance L1 between the first weld 211 and the rubber frame, the rotation angle θ of the torque M is reduced, thereby reducing the work W done by the torque M and improving the influence of the expansion force F on the strength of the first weld 211 near the rubber frame. This improves the problem of abnormal bursting of the first weld 211 due to strength decay.

[0160] Optionally, the middle portion of the first outer edge 111 in the first direction X is recessed towards the side where the heat insulation pad is located compared to the two ends. The middle portion has a simple form and flexible position, and its shape and size can be adjusted according to the size of the battery cell 10. That is, the frame 12 of the heat insulation pad near the first weld 211 is designed with an inward shape, which reduces the impact on the strength of the bottom first weld 211 while ensuring the heat insulation area. There are various design forms, such as the shape shown in Figure 7.

[0161] For ease of description, the orientation shown in Figure 5 is used as an example. The width d1 of the first frame 1211 along the second direction Y is 6mm; the second frame 1212 is the upper frame, and the second outer edge 112 is the upper edge of the outer edge 11. Along the second direction Y, the width d2 of the second frame 1212 is 6mm, and the distance L2 between the second outer edge 112 and the upper end of the shell 2 is in the range of 0 to 3mm; the third frame 1213 is the left frame, and the third outer edge 113 is the left edge of the outer edge 11. Along the first direction X, the width d3 of the third frame 1213 is 9mm, and the distance L2 between the third outer edge 113 and the upper end of the shell 2 is... The distance L3 at the left end is 6mm; the fourth frame 1214 is the right frame, and the fourth outer edge 114 is the right edge of the outer edge 11. Along the first direction X, the width d4 of the fourth frame 1214 is 9mm, and the distance L4 between the fourth outer edge 114 and the right end of the housing 2 is 6mm. Along the second direction Y, the width of the second frame 1212 is less than the width of the first frame 1211.

[0162] The distance L2 between the second outer edge 112 and the upper end of the housing 2 is set to be in the range of 0 to 3 mm, which allows the spacer 1 to be moved upward as a whole without changing the existing process and production equipment, thus simplifying production. The structural design in which the width d2 of the second frame 1212 along the second direction Y is smaller than the width d2 of the first frame 1211 is simple, highly operable, and low in cost.

[0163] The frame 12 can be two layers stacked along the wall thickness direction, both layers of frame 12 can be made of rubber; alternatively, one layer of frame 12 can be made of rigid material and the other of elastic material. On the one hand, the two layers of frame 12 not only provide support and sealant but also improve the structural stability of the spacer 1 itself; on the other hand, the two layers of frame 12 can absorb the cyclic expansion force F of the battery cell 10, thereby mitigating the expansion force F acting on the battery cell 10, especially reducing the expansion force F acting on the first weld 211 region, and weakening the impact on the strength of the first weld 211. In this way, the cooperation of all aspects improves the overall performance of the spacer 1.

[0164] The above embodiments are merely illustrative of the technical solutions of this disclosure and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure, and all should be covered within the scope of this disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. This disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of this disclosure.

Claims

1. A single battery cell, comprising: The shell has a plurality of shell walls that enclose a receiving space, wherein at least on the first shell wall a first weld extending in a first direction is formed; A spacer is disposed on the outer surface of the first housing wall. The spacer has an outer edge located in the plane of the outer surface of the first housing wall. The outer edge extending along the first direction and closest to the first weld along the second direction is the first outer edge. The distance between the first outer edge and the first weld along the second direction is greater than 0 and not more than 5 mm. The first direction, the second direction and the wall thickness direction of the housing wall are perpendicular to each other.

2. The battery cell according to claim 1, wherein, The distance between the first outer edge and the first weld along the second direction is in the range of 1.5 mm to 5 mm.

3. The battery cell according to claim 2, wherein, The distance between the first outer edge and the first weld along the second direction is in the range of 2.5 mm to 5 mm.

4. The battery cell according to any one of claims 1 to 3, wherein, The spacer includes a frame and a spacer pad, the frame being disposed around the spacer pad, and the outer edge of the frame that is closest to the first weld is the first outer edge.

5. The battery cell according to claim 4, wherein, The outer edge of the frame further includes a second outer edge, which is parallel to the first outer edge and spaced apart from the first outer edge along the second direction. Along the second direction, the first housing wall includes an edge opposite the first weld, separated by the spacer, the distance between the edge and the second outer edge being in the range of 0 to 3 mm.

6. The battery cell according to claim 5, wherein, The frame includes a first frame and a second frame spaced apart along the second direction. The first frame is elongated and includes a first outer edge, and the second frame is elongated and includes a second outer edge. The width dimension of the first frame along the second direction is different from the width dimension of the second frame along the second direction.

7. The battery cell according to claim 5, wherein, The first outer edge of the frame is configured such that the middle portion along the first direction is recessed towards the side where the spacer pad is located compared to the two end portions. The furthest distance between the first outer edge and the first weld along the second direction is greater than 0 and does not exceed 5 mm.

8. The battery cell according to claim 7, wherein, The frame includes a first frame and a second frame spaced apart along the second direction, wherein the first frame is configured such that the middle portion along the first direction is more oriented toward the spacer pad than the two end portions. The side is recessed, the middle part of the first frame is formed into a strip shape and includes the first outer edge, and the second frame is formed into a strip shape and includes the second outer edge.

9. The battery cell according to any one of claims 4 to 8, wherein, The frame includes a first frame and a second frame spaced apart along the second direction, and a third frame and a fourth frame spaced apart along the first direction. The first frame, the second frame, the third frame, and the fourth frame form a ring.

10. The battery cell according to any one of claims 1 to 9, wherein, The first shell wall is the shell wall with the largest outer surface area among the plurality of shell walls.

11. The battery cell according to any one of claims 4 to 10, wherein, The frame is a layered structure, which includes at least a first frame layer and a second frame layer stacked along the wall thickness direction, with the first frame layer disposed between the shell and the second frame layer.

12. The battery cell according to claim 11, wherein, The first border layer and the second border layer are made of materials with different hardness.

13. The battery cell according to any one of claims 4 to 12, wherein, The frame is a rubber frame, and the spacer is a heat insulation pad.

14. A battery comprising a housing and a plurality of battery cells according to any one of claims 1 to 13 housed within the housing, the battery cells being arranged in an array. Along the arrangement direction of the battery cells, the first housing wall of one battery cell faces the second housing wall of another adjacent battery cell, and the spacer is located at least between the facing first housing wall and the second housing wall.

15. An electrical device comprising a battery cell according to any one of claims 1 to 13 or a battery according to claim 14, wherein the battery cell is capable of storing electrical energy and providing electrical energy.

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