Battery cell, battery and electric device

Abstract

Disclosed in the present application are a battery cell, a battery and an electric device. The battery cell comprises a housing, an electrode assembly and a pressure relief mechanism, wherein the housing has an accommodating space and a first wall part; the electrode assembly is located in the accommodating space and has a first tab, the first tab is located on the side of the electrode assembly facing the first wall part, and the first tab is connected to the first wall part and divides the accommodating space into a first sub-space and a second sub-space; and the pressure relief mechanism is arranged on the housing and configured to be actuated when the internal pressure of the first sub-space reaches a threshold value, so as to release the internal pressure of the first sub-space. A communicating channel is constructed in the first wall part and connects the first sub-space to the second sub-space. Thus, the internal pressure of the battery cell can be rapidly balanced, the pressure relief mechanism has a good timely pressure-relief performance, and the use reliability of the battery cell is good.

Description

Battery cells, batteries and electrical devices

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 14, 2023, with application number 202323062094.9 and invention name “Battery Cell, Battery and Electrical Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0003] With the rapid development of new energy technologies, new energy vehicles are being used more and more widely. Batteries, as the power source of new energy vehicles, are one of the core devices of new energy vehicles. Batteries are usually equipped with one or more battery cells to meet the high-power usage requirements of batteries.

[0004] In order to improve the reliability of battery cells, battery cells are usually equipped with a pressure relief mechanism, and the internal pressure of the battery cells is released in a timely manner through the pressure relief mechanism to reduce the risk of further aggravation of thermal runaway of the battery cells; however, in actual use, the pressure in some areas of the battery cells is difficult to be released in a timely manner by the pressure relief mechanism, resulting in an imbalance in the internal pressure of the battery cells, which affects the reliability of the battery cells.

[0005] Application Contents

[0006] The purpose of the embodiments of the present application is to provide a battery cell, a battery and an electrical device, including but not limited to solving the problem in the related art that the pressure in some areas of the battery cell is difficult to be released by the pressure relief mechanism, thereby affecting the reliability of the battery cell.

[0007] The technical solution adopted in the embodiment of this application is:

[0008] In a first aspect, a battery cell is provided, which includes a shell, an electrode assembly and a pressure relief mechanism, the shell having a storage space and a first wall portion; the electrode assembly is located in the storage space, the electrode assembly has a first pole ear, the first pole ear is located on the side of the electrode assembly facing the first wall portion, the first pole ear is connected to the first wall portion, and divides the storage space into a first subspace and a second subspace; the pressure relief mechanism is provided in the shell, the pressure relief mechanism is used to actuate when the internal pressure of the first subspace reaches a threshold value to release the internal pressure of the first subspace; wherein the first wall portion is constructed with a connecting channel, the connecting channel connecting the first subspace and the second subspace.

[0009] In the battery cell of the embodiment of the present application, when thermal runaway occurs, the emission medium generated by the electrode assembly enters the first subspace and the second subspace, and the internal pressure of the first subspace and the second subspace rises. When the internal pressure of the first subspace reaches a threshold value, the pressure relief mechanism is actuated, and the emission medium in the first subspace is discharged from the pressure relief mechanism, thereby releasing the internal pressure of the first subspace. Since the first subspace and the second subspace are connected by the connecting channel, the emission medium in the second subspace can also enter the first subspace through the connecting channel and then be discharged through the pressure relief mechanism, thereby releasing the internal pressure of the second subspace. This achieves rapid balance of the internal pressure of the battery cell, the timely pressure relief performance of the pressure relief mechanism is good, and the battery cell has good reliability.

[0010] In one embodiment, the communication channel includes a communication groove formed on a surface of the first wall portion facing the first tab, one end of the communication groove communicates with the first subspace, and the other end of the communication groove communicates with the second subspace.

[0011] By adopting the technical solution of this embodiment, processing the connecting groove on the surface of the first wall portion facing the first tab is simple, which is beneficial to improving the production efficiency of the battery cell.

[0012] In one embodiment, a supporting protrusion is formed on a groove wall surface of the communicating groove facing the first electrode tab.

[0013] By adopting the technical solution of this embodiment, the supporting protrusion can support the first pole ear, blocking the first pole ear from entering the connecting groove and closing the connecting groove, thereby improving the reliability of the connecting groove connecting the first subspace and the second subspace and improving the reliability of the battery cell.

[0014] In one embodiment, the supporting protrusion protrudes out of the communicating groove.

[0015] By adopting the technical solution of this embodiment, after the first pole ear is connected to the first wall portion, the first pole ear abuts against the supporting protrusion, so that the first pole ear is located outside the connecting groove, the first pole ear is difficult to enter the connecting groove and the connecting groove is closed. The reliability of the connecting groove connecting the first subspace and the second subspace is better, and the reliability of the battery cell is better.

[0016] In one embodiment, the depth of the communicating groove is T1, and the thickness of the first wall portion is T2, wherein 0.3≤T1 / T2≤0.6.

[0017] By adopting the technical solution of this embodiment, the design of 0.3≤T1 / T2≤0.6 can enable the first wall portion to take into account both structural strength and flow area, which is beneficial to improving the reliability of the battery cell.

[0018] In one embodiment, 0.4≤T1 / T2≤0.5.

[0019] By adopting the technical solution of this embodiment, the design of 0.4≤T1 / T2≤0.5 can enable the first wall portion to better balance structural strength and flow area, which is beneficial to improving the reliability of the battery cell.

[0020] In one embodiment, the first wall portion is circular, the width of the connecting groove is L, and the diameter of the first wall portion is D, wherein 0<L / D≤0.1.

[0021] By adopting the technical solution of this embodiment, the design of 0<L / D≤0.1 can also ensure that the area of ​​the first wall portion where the connecting groove is provided is not too large, and the first wall portion has good structural strength, which is beneficial to improving the reliability of the battery cell.

[0022] In one embodiment, 0.001≤L / D≤0.05.

[0023] By adopting the technical solution of this embodiment, the design of 0.001≤L / D≤0.05 can enable the first wall portion to better balance structural strength, connection strength and flow area, thereby effectively improving the reliability of the battery cell.

[0024] In one embodiment, the depth of the communicating groove is T1, wherein 0.1 mm ≤ T1 ≤ 0.6 mm.

[0025] By adopting the technical solution of this embodiment, the design of 0.1mm≤T1≤0.6mm can enable the first wall portion to take into account both structural strength and flow area, which is beneficial to improving the reliability of the battery cell.

[0026] In one embodiment, 0.3 mm ≤ T1 ≤ 0.5 mm.

[0027] By adopting the technical solution of this embodiment, the design of 0.3mm≤T1≤0.5mm can enable the first wall portion to better balance structural strength and flow area, which is beneficial to improving the reliability of the battery cell.

[0028] In one embodiment, the width of the communicating groove is L, wherein 0.3 mm ≤ L ≤ 20 mm.

[0029] By adopting the technical solution of this embodiment, the design of 0.3mm≤L≤20mm can enable the first wall portion to better balance structural strength, connection strength and flow area, thereby effectively improving the reliability of the battery cell.

[0030] In one embodiment, 5 mm ≤ L ≤ 10 mm.

[0031] By adopting the technical solution of this embodiment, the design of 5mm≤L≤10mm can enable the first wall portion to better take into account the structural strength, connection strength and flow area at the same time, thereby effectively improving the reliability of the battery cell.

[0032] In one embodiment, there are multiple communication channels, and the multiple communication channels are distributed at intervals along the circumference of the first electrode tab.

[0033] By adopting the technical solution of this embodiment, the first subspace and the second subspace are connected by multiple connecting channels, and the emission medium in the second subspace can be discharged through the multiple connecting channels, which is conducive to quickly achieving the internal air pressure balance of the battery cell; in addition, the multiple connecting channels are distributed at intervals along the circumference of the first electrode, so that the emission medium at any position in the second subspace can quickly reach the connecting channels, realizing the timely discharge of the emission medium in the second subspace, and effectively improving the reliability of the battery cell.

[0034] In one embodiment, the first electrode tab is welded to the first wall portion to form a first welding structure; the projection of the first welding structure along the first direction and the projection of the connecting channel along the first direction do not overlap or partially overlap; wherein the first direction is the distribution direction of the first electrode tab and the first wall portion.

[0035] By adopting the technical solution of this embodiment, the first pole ear is directly welded to the first wall portion, and the assembly operation of the battery cell is simple; in addition, the projection of the first welding structure along the first direction and the projection of the connecting channel along the first direction do not overlap or partially overlap, so that the first pole ear and the first wall portion are welded in sections. On the one hand, the welding can avoid at least part of the connecting channel, so that the first welding structure will not close the connecting channel, thereby realizing the connection between the first subspace and the second subspace; on the other hand, the distance between the first pole ear and the first wall portion generated by the previous welding will not accumulate in the latter welding, thereby reducing the accumulation of the distance between the first pole ear and the first wall portion, improving the welding quality of the first welding structure, and improving the reliability of the battery cell.

[0036] In one embodiment, the battery cell further includes a first current collecting member located between the first pole tab and the first wall portion, and the first current collecting member is connected to the first pole tab; the first current collecting member is welded to the first wall portion to form a second welding structure; the projection of the second welding structure along the first direction and the projection of the connecting channel along the first direction do not overlap or partially overlap; wherein the first direction is the distribution direction of the first pole tab and the first wall portion.

[0037] By adopting the technical solution of this embodiment, the first wall portion is connected to the first pole tab through the first current collecting member, and the first wall portion can be tightly welded to the first current collecting member, which can reduce the risk of microcracks in the first wall portion, improve the sealing performance of the shell, and improve the reliability of the battery cell; and, when the first current collecting member is welded to the first pole tab, even if microcracks appear in the first current collecting member, it will not affect the sealing performance of the shell; in addition, similarly, the projection of the second welding structure along the first direction and the projection of the connecting channel along the first direction do not overlap or partially overlap, so that the first current collecting member and the first wall portion are welded in sections. On the one hand, the welding can avoid at least part of the connecting channel, so that the second welding structure will not close the connecting channel, thereby realizing the connection between the first subspace and the second subspace; on the other hand, the distance between the first current collecting member and the first wall portion generated by the previous welding will not accumulate in the subsequent welding, thereby reducing the accumulation of the distance between the first current collecting member and the first wall portion, improving the welding quality of the second welding structure, and improving the reliability of the battery cell.

[0038] In one embodiment, a surface of the first wall portion facing away from the first electrode tab is provided with an identification structure, and the identification structure is used to identify the position of the communication channel.

[0039] By adopting the technical solution of this embodiment, during the welding process between the first wall portion and the first current collecting member or the first pole ear, welding can be performed by avoiding the connecting channel according to the identification structure, the connection between the first subspace and the second subspace is reliable and stable, the pressure relief of the battery cell is timely, and the battery cell has good reliability in use.

[0040] In one embodiment, the identification structure includes at least one of an identification protrusion, an identification groove, a sticker, and a steel stamp.

[0041] By adopting the technical solution of this embodiment, the identification structure can be flexibly set to meet different production requirements.

[0042] In one embodiment, the first wall portion includes a main body and a protrusion, the protrusion is arranged to protrude relative to the surface of the main body toward the first pole ear, the protrusion is arranged around the main body, the connecting channel is arranged on the protrusion, the pressure relief mechanism is arranged on the main body, the protrusion is abutted against and connected to the first pole ear, and a pressure relief gap for communicating with the connecting channel is formed between the main body and the first pole ear, and the pressure relief gap is located in the first subspace.

[0043] By adopting the technical solution of this embodiment, the discharge medium of the second subspace enters the pressure relief gap through the connecting channel, and can quickly flow to the pressure relief mechanism through the pressure relief gap, and finally be discharged through the pressure relief mechanism, which can achieve internal pressure balance of the battery cell more quickly and improve the reliability of the battery cell. In addition, the pressure relief gap can provide an actuation space for the pressure relief mechanism, and the pressure relief mechanism can be actuated in time to relieve pressure, thereby improving the timeliness of pressure relief of the battery cell.

[0044] In one embodiment, the housing includes a shell and an end cover, the end cover covers the opening of the shell, the end cover and the shell together enclose a receiving space, and the end cover is the first wall portion; or, the wall portion of the shell is the first wall portion.

[0045] By adopting the technical solution of this embodiment, the electrode assembly can be placed into the shell through the opening of the shell, and then the opening of the shell is closed by the end cover, so that the electrode assembly is encapsulated in the outer shell, the assembly operation is simple, and it is beneficial to improve the production efficiency of the battery cell.

[0046] In one embodiment, the electrode assembly further has a second pole tab, which is located on the side of the electrode assembly facing away from the first wall portion, and the polarity of the first pole tab is opposite to that of the second pole tab; the battery cell further includes an electrode terminal and a first insulating member, the outer shell has a second wall portion arranged opposite to the first wall portion, the second wall portion is provided with an electrode lead-out hole connected to the accommodating space, the first insulating member is sleeved on the outside of the electrode terminal, and the first insulating member is passed through the electrode lead-out hole to insulate the electrode terminal and the outer shell; the second pole tab is connected to the electrode terminal to make the second pole tab electrically connected to the electrode terminal.

[0047] By adopting the technical solution of this embodiment, the housing serves as one output stage of the battery cell, the electrode terminals serve as another output stage of the battery cell, and the housing and the electrode terminals are connected to an external circuit to realize charging and discharging of the battery cell.

[0048] In one embodiment, the electrode assembly further includes a second current collecting member and a second insulating member, wherein the second current collecting member is connected between the second electrode tab and the electrode terminal to achieve electrical connection between the second electrode tab and the electrode terminal; at least a portion of the second insulating member is located between the second current collecting member and the second wall portion.

[0049] By adopting the technical solution of this embodiment, the second pole tab and the electrode terminal are connected through the second current collector. The second current collector can support the second pole tab and the electrode terminal, improve the connection stability between the second pole tab and the electrode terminal, and help improve the reliability of the battery cell. In addition, the second insulating member can insulate and separate the second current collector from the outer shell, reducing the risk of short circuit.

[0050] In one embodiment, the battery cell further includes a sealing member, the electrode terminal is configured with a liquid injection hole communicating with the accommodation space, and the sealing member covers the opening of the liquid injection hole facing away from the electrode assembly to seal the liquid injection hole.

[0051] By adopting the technical solution of this embodiment, the provision of the injection hole can realize the injection of the battery cell, and the sealing member can seal the injection hole to reduce the risk of electrolyte leakage.

[0052] In a second aspect, a battery is provided, comprising the battery cell according to the above embodiment.

[0053] The battery of the embodiment of the present application adopts the above-mentioned battery cell, which has good reliability in use and improves the reliability and performance of the battery.

[0054] In a third aspect, an electrical device is provided, comprising a battery according to the above embodiment.

[0055] The electrical device of the embodiment of the present application adopts the above-mentioned battery, which has good reliability and performance, thereby improving the reliability and performance of the electrical device.

[0056] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0058] FIG1 is a schematic structural diagram of a vehicle provided in one embodiment of the present application.

[0059] FIG2 is a schematic structural diagram of a battery provided in another embodiment of the present application.

[0060] FIG3 is a schematic structural diagram of a battery cell provided in yet another embodiment of the present application.

[0061] FIG4 is an exploded schematic diagram of the battery cell shown in FIG3 .

[0062] FIG5 is a cross-sectional view taken along line AA in FIG3 .

[0063] FIG6 is a partial enlarged view of point B in FIG5.

[0064] FIG7 is a partial enlarged view of a battery cell provided in yet another embodiment of the present application at point B in FIG5 .

[0065] FIG8 is a schematic structural diagram of an end cover provided in yet another embodiment of the present application.

[0066] FIG9 is a schematic structural diagram of an end cover provided in yet another embodiment of the present application.

[0067] FIG10 is a schematic structural diagram of an end cover provided in yet another embodiment of the present application.

[0068] FIG11 is a cross-sectional view taken along line CC in FIG10 .

[0069] FIG12 is a partial enlarged view of point D in FIG11 .

[0070] FIG13 is a partial enlarged view of the end cover provided in another embodiment of the present application at point D in FIG11 .

[0071] In the figures, the following reference numerals are used: 1000, vehicle; 1100, battery; 1200, controller; 1300, motor; 10, housing; 11, first portion; 12, second portion; 20, battery cell; 21, housing; 2101, accommodating space; 2102, first subspace; 2103, second subspace; 2104, pressure relief gap; 211, first wall; 2111, connecting channel; 2112, connecting groove; 2113, supporting protrusion; 2114, identification structure; 21141, identification protrusion; 2115, body; 2116, protrusion; 2117, extension; 212, end cover; 213, housing; 214, second wall; 214 1. Electrode lead-out hole; 22. Electrode assembly; 221. First electrode tab; 222. Second electrode tab; 223. Center hole; 23. Pressure relief mechanism; 231. Annular groove; 24. First current collecting member; 241. First connecting hole; 25. Electrode terminal; 251. Liquid injection hole; 26. First insulating member; 27. Second current collecting member; 271. Second connecting hole; 28. Second insulating member; 29. ​​Sealing member; W, connecting structure; W1, first welding structure; W2, second welding structure; W3, third welding structure. DETAILED DESCRIPTION

[0072] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0073] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0074] In the description of the embodiments of this application, the technical terms "first," "second," etc., are used solely to distinguish between different objects and should not be understood to indicate or imply relative importance, or to implicitly specify the quantity, specific order, or primary-secondary relationship of the technical features indicated. Therefore, a feature designated "first" or "second" may explicitly or implicitly include one or more of such features.

[0075] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments in any suitable manner.

[0076] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0077] In the description of the embodiments of this application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more (including two groups), and "multiple sheets" refers to two or more (including two sheets). "Several" means one or more, unless otherwise specifically defined.

[0078] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0079] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0080] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, when an element is referred to as being “fixed to” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0081] With the rapid development of new energy technologies, new energy vehicles are being used more and more widely. Batteries, as the power source of new energy vehicles, are one of the core devices of new energy vehicles. Batteries are usually equipped with one or more battery cells to meet the high-power usage requirements of batteries.

[0082] In order to improve the reliability of battery cells, battery cells are usually equipped with a pressure relief mechanism, and the internal pressure of the battery cells is released in a timely manner through the pressure relief mechanism to reduce the risk of further aggravation of thermal runaway of the battery cells; however, in actual use, the pressure in some areas of the battery cells is difficult to be released in a timely manner by the pressure relief mechanism, resulting in an imbalance in the internal pressure of the battery cells, which affects the reliability of the battery cells.

[0083] A battery cell may refer to the smallest electrical energy storage unit in a battery. A battery cell generally includes a casing and an electrode assembly. A containing space is formed inside the casing, and the electrode assembly is located inside the containing space. In the event of thermal runaway of the battery cell, the electrode assembly will produce a large amount of emission medium, thereby causing the pressure inside the containing space to rise. In order to improve the reliability of the battery cell, a pressure relief mechanism is generally provided on the casing. When the pressure in the containing space reaches a threshold, the pressure relief mechanism is actuated, and the emission medium in the containing space is discharged outwardly. The pressure in the containing space is released in a timely manner, thereby reducing the risk of explosion of the battery cell.

[0084] In some cases, the tabs of the electrode assembly are connected to the opposite wall of the housing to facilitate current extraction from the electrode assembly. The wall of the housing is welded to the tab along its circumference. However, the welding of the tabs to the housing forms a welded structure, which divides the storage space into two subspaces that are difficult to connect. In addition, the pressure relief mechanism provided on the housing corresponds to only one of the subspaces. As a result, when a battery cell experiences thermal runaway, the pressure relief mechanism can only promptly relieve the internal pressure of the corresponding subspace. The pressure in the other subspace cannot be promptly transmitted to the pressure relief mechanism for relief, resulting in an imbalance in the internal pressure of the battery cell, which seriously affects the reliability of the battery cell.

[0085] In order to improve the reliability of battery cells, an embodiment of the present application provides a battery cell, wherein the first pole ear of the electrode assembly of the battery cell is connected to the first wall portion of the shell, and the accommodating space is divided into a first subspace and a second subspace; at the same time, the pressure relief mechanism can release the internal pressure of the first subspace, and the first wall portion is constructed with a connecting channel, which connects the first subspace and the second subspace, so that the internal pressure of the second subspace can be transmitted to the first subspace through the connecting channel, and then released through the pressure relief mechanism, thereby realizing rapid balance of the internal pressure of the battery cell, the timely pressure relief performance of the pressure relief mechanism is good, and the reliability of the battery cell is good.

[0086] The battery cells, batteries, and electrical devices using the batteries as power sources disclosed in the embodiments of the present application may include, but are not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, and the like. Electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft.

[0087] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0088] Please refer to Figure 1. Vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 1100 is provided inside the vehicle 1000. The battery 1100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 1100 can be used to power the vehicle 1000. For example, the battery 1100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 can also include a controller 1200 and a motor 1300. The controller 1200 is used to control the battery 1100 to power the motor 1300, for example, for starting, navigating and driving the vehicle 1000.

[0089] In some embodiments of the present application, the battery 1100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0090] Referring to Figure 2, as an embodiment of a battery 1100, the battery 1100 includes a housing 10 and a battery cell 20, with the battery cell 20 being housed within the housing 10. The housing 10 is used to provide a storage space 2101 for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which cover each other and together define a storage space 2101 for accommodating the battery cell 20. The second portion 12 can be a hollow structure with one end open, and the first portion 11 can be a plate-like structure, with the first portion 11 covering the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define the storage space 2101. The first portion 11 and the second portion 12 can also be hollow structures with one end open, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0091] In the battery 1100 , there may be multiple battery cells 20 , and the multiple battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 20 are connected in both series and in parallel.

[0092] For example, the battery 1100 includes one or more battery cells 20. When the battery 1100 includes multiple battery cells 20, the multiple battery cells 20 can be directly connected in series, in parallel, or mixed together, and then the entire battery cell 20 can be accommodated in the casing 10. The battery cell 20 can be a lithium-ion secondary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, etc. The battery cell 20 can be cylindrical, flat, rectangular, or in other shapes, etc. The battery cell 20 can be packaged in different ways to form a cylindrical battery cell, a square battery cell, or a soft-pack battery cell, etc.

[0093] Alternatively, the battery cell 20 may be a battery module 1100 or a battery module 1100. At least two battery cells 20 may be connected in series, parallel, or in series to form a modular structure, i.e., a battery module or a battery module. At least two battery modules or battery modules may then be connected in series, parallel, or in series to form a whole structure, which is housed in the housing 10.

[0094] As another embodiment of the battery 1100 , the battery 1100 may not include the housing 10 , but may be assembled into the vehicle 1000 after electrically connecting a plurality of battery cells 20 ; or may be assembled into the vehicle 1000 after forming a whole through some fixed structures.

[0095] As shown in Figures 3 to 5 , a battery cell 20 is the smallest unit that makes up the battery 1100. The battery cell 20 includes a housing 21 and an electrode assembly 22. The housing 21 is used to enclose a housing space 2101, which serves as the internal environment of the battery cell 20 and is used to accommodate the electrode assembly 22. The housing 21 also isolates the internal environment of the battery cell 20 from the external environment.

[0096] As an example, the housing 21 includes an end cover 212 and a shell 213. The end cover 212 refers to a component that covers the opening of the shell 213 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cover 212 can be adapted to the shape of the shell 213 to match the shell 213. Optionally, the end cover 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cover 212 is not easily deformed when squeezed and collided, so that the battery cell 20 can have higher structural strength and improved safety performance. The material of the end cover 212 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this.

[0097] The housing 213 is a component that cooperates with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 213 and the end cap 212 can be separate components. An opening can be provided in the housing 213, and the end cap 212 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 213 can be integrated. Specifically, the end cap 212 and the housing 213 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 213 is to be enclosed, the end cap 212 is placed over the housing 213. The housing 213 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 213 can be determined based on the specific shape and size of the electrode assembly 22. The housing 213 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0098] The electrode assembly 22 is the component in the battery cell 20 where the electrochemical reaction occurs. One or more electrode assemblies 22 may be contained within the housing 213. The electrode assembly 22 includes a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell 20 primarily relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to operate. The positive electrode sheet includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector; the positive current collector includes a positive current collecting area and a positive electrode tab protruding from the positive current collecting area, and the positive current collecting area is coated with the positive active material layer, while at least a portion of the positive electrode tab is not coated with the positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector may be aluminum, and the positive active material layer includes a positive active material, which may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, with the negative active material layer coated on the surface of the current collector. The negative current collector includes a negative current collecting region and a negative electrode tab protruding from the negative current collecting region. The negative current collecting region is coated with the negative active material layer, while at least a portion of the negative electrode tab is uncoated with the negative active material layer. The negative current collector can be made of copper, and the negative active material layer includes a negative active material, such as carbon or silicon. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0099] In one embodiment, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0100] Please refer to Figure 6 for reference. An embodiment of the present application provides a battery cell 20, which includes a shell 21, an electrode assembly 22 and a pressure relief mechanism 23. The shell 21 has a accommodating space 2101 and a first wall portion 211; the electrode assembly 22 is located in the accommodating space 2101, and the electrode assembly 22 has a first pole ear 221. The first pole ear 221 is located on the side of the electrode assembly 22 facing the first wall portion 211, and the first pole ear 221 is connected to the first wall portion 211, and divides the accommodating space 2101 into a first subspace 2102 and a second subspace 2103; the pressure relief mechanism 23 is provided in the shell 21, and the pressure relief mechanism 23 is used to actuate when the internal pressure of the first subspace 2102 reaches a threshold value to release the internal pressure of the first subspace 2102; wherein the first wall portion 211 is constructed with a connecting channel 2111, and the connecting channel 2111 connects the first subspace 2102 and the second subspace 2103.

[0101] The shell 21 may refer to a component for accommodating the electrode assembly 22. The shell 21 includes multiple wall portions, which are connected and enclosed to form a accommodating space 2101. The accommodating space 2101 is used to accommodate the electrode assembly 22. The first wall portion 211 may refer to a wall portion in the shell 21 that is connected to the first electrode ear 221. In the shell 21, the first wall portion 211 may be an end cover 212 or a wall portion of the shell 213.

[0102] The electrode assembly 22 includes a first electrode sheet, a second electrode sheet, and a separator. The first electrode sheet, the second electrode sheet, and the separator are stacked and then wound to form a wound structure. The wound structure can be cylindrical in shape, but in other embodiments, the wound structure can also be flat or have other shapes. The separator is located between the first electrode sheet and the second electrode sheet to insulate the first electrode sheet from the second electrode sheet. The first electrode sheet and the second electrode sheet have opposite polarities, that is, one of the first electrode sheet and the second electrode sheet is a positive electrode sheet and the other is a negative electrode sheet.

[0103] The electrode assembly 22 is provided with a first electrode tab 221 and a second electrode tab 222. The first electrode tab 221 may refer to the portion of the first electrode sheet not coated with active material, and the second electrode tab 222 may refer to the portion of the second electrode sheet not coated with active material. Accordingly, one of the first electrode tab 221 and the second electrode tab 222 is the positive electrode tab, and the other is the negative electrode tab. The first electrode tab 221 and the second electrode tab 222 are located on opposite sides of the electrode assembly, with the first electrode tab 221 located on the side of the electrode assembly 22 facing the first wall 211, and the second electrode tab 222 located on the side of the electrode assembly 22 facing away from the first wall 211. As an example, the first electrode tab 221 is wound around the central axis X of the electrode assembly 22 and is generally cylindrical in shape. The second electrode tab 222 is wound around the central axis X of the electrode assembly 22 and is also generally cylindrical in shape. Of course, the structures of the first electrode tab 221 and the second electrode tab 222 may also differ.

[0104] After winding is completed, the first pole tab 221 is generally cylindrical, and a gap is left between two adjacent layers in the first pole tab 221. In the embodiment of the present application, the first pole tab 221 can be processed to reduce the gap between the layers, thereby facilitating the connection between the first pole tab 221 and the first wall portion 211. For example, in the embodiment of the present application, the first pole tab 221 can be flattened to gather and gather the end area of ​​the first pole tab 221 away from the main body; the flattening process forms a dense end surface at the end of the first pole tab 221 away from the main body, thereby reducing the gap between the layers and facilitating the connection between the first pole tab 221 and the first wall portion 211. Of course, in the embodiment of the present application, conductive material can also be filled between two adjacent layers to reduce the gap between the layers. Similarly, the second pole tab 222 can also be flattened or filled with conductive material to reduce the gap between the layers.

[0105] Referring to FIG8 , the first electrode tab 221 is connected to the first wall portion 211, dividing the accommodation space 2101 into a first subspace 2102 and a second subspace 2103. The first wall portion 211 is connected to the first electrode tab 221 along a circumferential direction Y of the first electrode tab 221, forming a connection structure W. The circumferential direction Y of the first electrode tab 221 may refer to a direction surrounding the central axis X of the electrode assembly 22, and the connection structure W is also disposed around the central axis X of the electrode assembly 22. After the first electrode tab 221 is connected to the first wall portion 211, the area within the accommodation space 2101 located inside the connection structure W and the area outside the connection structure W are difficult to communicate with each other. In other words, one of the first subspace 2102 and the second subspace 2103 may be located within the accommodation space 2101 inside the connection structure W, and the other may be located within the accommodation space 2101 outside the connection structure W.

[0106] When the electrode assembly 22 has a wound structure, the central axis X of the electrode assembly 22 is the winding axis of the electrode assembly 22. The shape of the first electrode tab 221 is adapted to the shape of the first wall portion 211 to improve the connection reliability between the first electrode tab 221 and the first wall portion 211. When the shape of the first electrode tab 221 is adapted to the shape of the first wall portion 211, the circumferential direction Y of the first electrode tab 221 can also be the circumferential direction of the first wall portion 211, and the radial direction of the first electrode tab 221 can also be the radial direction of the first wall portion 211. As an example, the shape of the first electrode tab 221 is circular, and the shape of the first wall portion 211 is also circular.

[0107] The first tab 221 and the first wall portion 211 can be connected in sections or in a full circle along the circumferential direction Y of the first tab 221 to improve the connection strength between the first tab 221 and the first wall portion 211. The first tab 221 and the first wall portion 211 can be connected by welding, bonding, or other methods to achieve electrical connection between the first tab 221 and the first wall portion 211. In this case, the housing 21 serves as the output stage of the battery cell 20, thereby eliminating one electrode terminal 25 and simplifying the structure of the battery cell 20. When multiple battery cells 20 are assembled into a group, the housing 21 can be electrically connected to the busbar over a large area, thereby increasing the flow area and making the busbar structure more flexible.

[0108] The pressure relief mechanism 23 may refer to a component in the battery cell 20 for releasing the internal pressure of the first subspace 2102; the pressure relief mechanism 23 is used to release the internal pressure when the internal pressure of the first subspace 2102 reaches a threshold value, thereby improving the safety performance of the battery cell 20. The threshold design varies according to different design requirements. The threshold value may depend on the material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 20. The pressure relief mechanism 23 can take the form of an explosion-proof valve, an air valve, a pressure relief valve, or a safety valve, and can specifically adopt a pressure-sensitive element or structure. That is, when the internal pressure of the battery cell 20 reaches a threshold value, the pressure relief mechanism 23 executes an action or the weak structure provided in the pressure relief mechanism 23 is destroyed, thereby forming an opening or channel for internal pressure relief. The pressure relief mechanism 23 can be arranged on the first wall portion 211, or on other wall portions of the outer shell 21, and is specifically set according to the position of the first subspace 2102; as an example, the pressure relief mechanism 23 can refer to a groove formed on the surface of the first wall portion 211 facing the accommodating space 2101, and the groove forms a weak structure. Of course, the groove can also be formed on the surface of the first wall portion 211 facing away from the accommodating space 2101. The shape of the groove can be a closed shape such as a circle, an ellipse, a polygon, or a non-closed shape such as a Y shape or an H shape.

[0109] "Actuation" means that the pressure relief mechanism 23 is in action or activated to a certain state, so that the internal pressure of the battery cell 20 can be released. The action produced by the pressure relief mechanism 23 may include but is not limited to: at least a part of the pressure relief mechanism 23 is broken, shattered, melted, torn or opened, etc. When the pressure relief mechanism 23 is actuated, the high-temperature and high-pressure substances inside the battery cell 20 will be discharged outward from the actuated part as a discharge medium. In this way, the battery cell 20 can be depressurized under controllable pressure, thereby avoiding potential more serious accidents. The discharge medium includes but is not limited to: electrolyte, dissolved or split positive and negative pole pieces, fragments of the isolation membrane, high-temperature and high-pressure gas produced by the reaction, flame, etc.

[0110] The communication channel 2111 may refer to a channel in the first wall portion 211 that connects the first subspace 2102 and the second subspace 2103. As an example, the communication channel 2111 may refer to a groove formed by a depression in the surface of the first wall portion 211 toward the first electrode tab 221, or may refer to a through hole provided in the first wall portion 211. Of course, other structures are also possible.

[0111] In the battery cell 20 of the embodiment of the present application, when thermal runaway occurs, the discharge medium generated by the electrode assembly 22 enters the first subspace 2102 and the second subspace 2103, and the internal pressure of the first subspace 2102 and the second subspace 2103 rises. When the internal pressure of the first subspace 2102 reaches a threshold, the pressure relief mechanism 23 is actuated, and the discharge medium in the first subspace 2102 is discharged from the pressure relief mechanism 23, thereby releasing the internal pressure of the first subspace 2102. Since the first subspace 2102 and the second subspace 2103 are connected by the connecting channel 2111, the discharge medium in the second subspace 2103 can also enter the first subspace 2102 through the connecting channel 2111 and then be discharged through the pressure relief mechanism 23, thereby releasing the internal pressure of the second subspace 2103. This achieves rapid balance of the internal pressure of the battery cell 20, the timely pressure relief performance of the pressure relief mechanism 23 is good, and the battery cell 20 has good reliability.

[0112] In another embodiment of the present application, please refer to Figures 6 and 8 , the connecting channel 2111 includes a connecting groove 2112, and the connecting groove 2112 is formed on the surface of the first wall portion 211 facing the first pole ear 221. One end of the connecting groove 2112 is connected to the first subspace 2102, and the other end of the connecting groove 2112 is connected to the second subspace 2103.

[0113] The connecting groove 2112 may refer to a groove structure formed by the surface depression of the first wall portion 211 toward the first pole tab 221. After the surface of the first wall portion 211 toward the first pole tab 221 is connected to the first pole tab 221, the connecting groove 2112 may connect the first subspace 2102 and the second subspace 2103; as an example, the connecting groove 2112 may extend along the radial direction of the first pole tab 221 to connect the first subspace 2102 and the second subspace 2103 located inside and outside the connection structure W. The shape of the connecting groove 2112 may be an arc, a broken line, a rectangle (as shown in conjunction with FIG8), a fan (as shown in conjunction with FIG9 and FIG10), or other shapes. Of course, the connecting groove 2112 may also extend in other directions.

[0114] By adopting the technical solution of this embodiment, processing the communicating groove 2112 on the surface of the first wall portion 211 facing the first electrode tab 221 is simple, which is beneficial to improving the production efficiency of the battery cell 20 .

[0115] In another embodiment of the present application, as shown in conjunction with FIG. 10 and FIG. 11 , a supporting protrusion 2113 is constructed on the wall surface of the communicating groove 2112 facing the first electrode tab 221 .

[0116] The supporting protrusion 2113 may refer to a protrusion formed on the wall surface of the communicating groove 2112 facing the first electrode tab 221 .

[0117] By adopting the technical solution of this embodiment, the support protrusion 2113 can support the first pole ear 221, blocking the first pole ear 221 from entering the connecting groove 2112 and closing the connecting groove 2112, thereby improving the reliability of the connecting groove 2112 connecting the first subspace 2102 and the second subspace 2103, and improving the reliability of the battery cell 20.

[0118] In one embodiment, the number of support protrusions 2113 can be multiple, and the multiple support protrusions 2113 are distributed at intervals. The multiple support protrusions 2113 can provide multi-point support for the first pole ear 221, and can better block the first pole ear 221 from entering the connecting groove 2112 and close the connecting groove 2112.

[0119] In another embodiment of the present application, as shown in conjunction with FIG. 10 and FIG. 11 , the support protrusion 2113 protrudes out of the connecting groove 2112 .

[0120] It is understood that the height H of the support protrusion 2113 is greater than the groove depth T1 of the connecting groove 2112, that is, the support protrusion 2113 partially protrudes outside the connecting groove 2112. The degree to which the support protrusion 2113 protrudes from the connecting groove 2112 can be set according to actual needs and is not limited here.

[0121] By adopting the technical solution of this embodiment, after the first pole ear 221 is connected to the first wall portion 211, the first pole ear 221 abuts against the support protrusion 2113, and the first pole ear 221 is located outside the connecting groove 2112. It is more difficult for the first pole ear 221 to enter the connecting groove 2112 and close the connecting groove 2112. The reliability of the connecting groove 2112 connecting the first subspace 2102 and the second subspace 2103 is better, and the reliability of the battery cell 20 is better.

[0122] In another embodiment of the present application, referring to FIG. 10 and FIG. 11 , the depth of the connecting groove 2112 is T1 , and the thickness of the first wall portion 211 is T2 , wherein 0.3≤T1 / T2≤0.6.

[0123] The first wall portion 211 is a plate-shaped structure. The first wall portion 211 has a first surface and a second surface that are oppositely distributed along the thickness direction Z. The first surface is disposed facing the first electrode tab 221, and the second surface is disposed away from the first electrode tab 221.

[0124] The distance between the wall surface of the connecting groove 2112 facing the first electrode tab 221 and the first surface is the groove depth T1 of the connecting groove 2112. If the wall surface of the connecting groove 2112 facing the first electrode tab 221 is flat, the groove depth T1 of the connecting groove 2112 is measured with respect to the flat surface. If the wall surface of the connecting groove 2112 facing the first electrode tab 221 is formed with a protrusion or a recess, the groove depth T1 of the connecting groove 2112 is measured with respect to the flat area of ​​the wall surface of the connecting groove 2112 facing the first electrode tab 221. If the first surface is flat, the groove depth T1 of the connecting groove 2112 is measured with respect to the first surface. If the first surface is formed with a protrusion and the connecting groove 2112 is located on the protrusion, the groove depth T1 of the connecting groove 2112 is measured with respect to the surface of the protrusion facing the first electrode tab 221.

[0125] The distance between the first surface and the second surface is the wall thickness T2 of the first wall portion 211; if the first surface and the second surface are planes, the wall thickness T2 of the first wall portion 211 is measured based on the first surface and the second surface; if the first surface and the second surface are formed with convex or concave portions, the wall thickness T2 of the first wall portion 211 is measured based on the plane area of ​​the first surface and the second surface.

[0126] T1 / T2, as can be understood, refers to the proportion of the communicating groove 2112 in the thickness direction Z of the first wall portion 211 .

[0127] By adopting the technical solution of this embodiment, the design of T1 / T2≥0.3, the connecting groove 2112 has a certain flow area, the discharge medium of the second subspace 2103 can easily enter the first subspace 2102 for release, and the second subspace 2103 has a good pressure relief effect, so that the first subspace 2102 and the second subspace 2103 can reach equilibrium more quickly; at the same time, the design of T1 / T2≤0.6 makes the first wall portion 211 have a certain thickness at the connecting groove 2112, and the first wall portion 211 has a certain structural strength, reducing the risk of the first wall portion 211 being damaged. Therefore, the design of 0.3≤T1 / T2≤0.6 allows the first wall portion 211 to take into account both structural strength and flow area, which is beneficial to improving the reliability of the battery cell 20.

[0128] In another embodiment of the present application, referring to FIG. 10 and FIG. 11 , 0.4≤T1 / T2≤0.5.

[0129] By adopting the technical solution of this embodiment, the design of T1 / T2≥0.4, the connecting groove 2112 has a reasonable flow area, the discharge medium of the second subspace 2103 can quickly enter the first subspace 2102 for release, and the pressure relief effect of the second subspace 2103 is better, so that the first subspace 2102 and the second subspace 2103 can quickly reach equilibrium; at the same time, the design of T1 / T2≤0.5 makes the first wall portion 211 have a more reasonable thickness at the connecting groove 2112, the first wall portion 211 has better structural strength, and effectively reduces the risk of the first wall portion 211 being damaged. Therefore, the design of 0.4≤T1 / T2≤0.5 can enable the first wall portion 211 to better take into account both structural strength and flow area at the same time, which is beneficial to improving the reliability of the battery cell 20.

[0130] In one embodiment, the value of T1 / T2 may be, but is not limited to, any one of 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, or any value therebetween.

[0131] In another embodiment of the present application, as shown in Figures 8 to 10, the first wall portion 211 is circular, the width of the communicating groove 2112 is L, and the diameter of the first wall portion 211 is D, wherein 0<L / D≤0.1.

[0132] In the connecting groove 2112, the minimum distance between two groove walls on opposite sides of the groove wall facing the first electrode tab 221 is the groove width L of the connecting groove 2112. As shown in FIG8 , if the two groove walls are parallel, that is, the connecting groove 2112 is rectangular in shape, the groove width L of the connecting groove 2112 is measured using any position of the two groove walls as a reference. As shown in FIG9 and FIG10 , if the two groove walls form a certain angle, that is, the connecting groove 2112 is fan-shaped, the groove width L of the connecting groove 2112 is measured using the minimum distance between the two groove walls as a reference.

[0133] The first wall portion 211 is circular in shape. The first wall portion 211 is placed between two parallel planes. When the two planes are aligned with the circumferential surface of the first wall portion 211 , the distance between the two planes is the diameter D of the first wall portion 211 .

[0134] 0<L / D≤0.1. It can be understood that the larger the diameter D of the first wall portion 211, the larger the volume of the electrode assembly 22. In the event of thermal runaway, the electrode assembly 22 generates more discharge medium, and the internal pressure in the battery cell 20 becomes greater. The groove width L of the connecting groove 2112 can also be set larger, and the flow area of ​​the connecting groove 2112 also increases, so that a large amount of discharge medium in the second subspace 2103 can quickly flow into the first subspace 2102 through the connecting groove 2112, and then be discharged through the pressure relief mechanism 23, so that the air pressure in the battery cell 20 can quickly reach equilibrium; therefore, different connecting grooves 2112 can be designed according to the size of the battery cell 20 to meet the pressure relief requirements of battery cells 20 of different sizes.

[0135] By adopting the technical solution of this embodiment, the design of 0<L / D≤0.1 can also ensure that the area of ​​the first wall portion 211 where the communicating groove 2112 is provided is not too large. The first wall portion 211 has good structural strength, which is beneficial to improving the reliability of the battery cell 20.

[0136] In another embodiment of the present application, as shown in Figures 8 to 10 , 0.001≤L / D≤0.05.

[0137] By adopting the technical solution of this embodiment, the design of L / D≥0.001 makes it possible that when the diameter D of the first wall portion 211 is constant, the groove width L of the connecting groove 2112 is reasonable, the connecting groove 2112 has a reasonable flow area, and the second subspace 2103 can quickly relieve pressure; the design of L / D≤0.05 makes the area occupied by the connecting groove 2112 of the first wall portion 211 within a reasonable range, the first wall portion 211 also has a reasonable area to connect with the first pole ear 221, the connection reliability between the first pole ear 221 and the first wall portion 211 is good, and at the same time, the first wall portion 211 also has a more reasonable structural strength. Therefore, the design of 0.001≤L / D≤0.05 can enable the first wall portion 211 to better take into account the structural strength, connection strength and flow area at the same time, effectively improving the reliability of the battery cell 20.

[0138] In one embodiment, the value of L / D may be, but is not limited to, any one of 0.0001, 0.001, 0.005, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, or any value therebetween.

[0139] In another embodiment of the present application, as shown in combination with FIG. 10 and FIG. 11 , the depth of the communicating groove 2112 is T1 , wherein 0.1 mm ≤ T1 ≤ 0.6 mm.

[0140] By adopting the technical solution of this embodiment, the design of T1≥0.1mm allows the connecting groove 2112 to have a certain flow area, and the discharge medium of the second subspace 2103 can easily enter the first subspace 2102 for release. The second subspace 2103 has a good pressure relief effect, so that the first subspace 2102 and the second subspace 2103 can reach equilibrium more quickly; at the same time, the design of T1≤0.6mm prevents the connecting groove 2112 from penetrating the first wall portion 211, and the first wall portion 211 has a certain structural strength, reducing the risk of damage to the first wall portion 211. Therefore, the design of 0.1mm≤T1≤0.6mm allows the first wall portion 211 to take into account both structural strength and flow area, which is beneficial to improving the reliability of the battery cell 20.

[0141] In another embodiment of the present application, 0.3 mm ≤ T1 ≤ 0.5 mm.

[0142] By adopting the technical solution of this embodiment, the design of T1 / T2≥0.3mm, the connecting groove 2112 has a reasonable flow area, the discharge medium of the second subspace 2103 can quickly enter the first subspace 2102 for release, and the pressure relief effect of the second subspace 2103 is better, so that the first subspace 2102 and the second subspace 2103 can quickly reach equilibrium; at the same time, the design of T1 / T2≤0.5mm makes the first wall portion 211 have a more reasonable thickness at the connecting groove 2112, the first wall portion 211 has better structural strength, and effectively reduces the risk of the first wall portion 211 being damaged. Therefore, the design of 0.3mm≤T1≤0.5mm can enable the first wall portion 211 to better take into account both structural strength and flow area at the same time, which is beneficial to improving the reliability of the battery cell 20.

[0143] In one embodiment, the value of T1 may be, but is not limited to, any one of 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, or any value therebetween.

[0144] In another embodiment of the present application, as shown in Figures 8 to 10, the width of the connecting groove 2112 is L, wherein 0.3 mm ≤ L ≤ 20 mm.

[0145] By adopting the technical solution of this embodiment, the design of L≥5mm, the connecting groove 2112 has a certain groove width, the connecting groove 2112 has a certain flow area, and the second subspace 2103 can quickly relieve pressure; the design of L≤20mm makes the area of ​​the connecting groove 2112 occupied by the first wall portion 211 within a reasonable range, and the first wall portion 211 also has a reasonable area to be connected to the first pole ear 221, and the connection reliability between the first pole ear 221 and the first wall portion 211 is good. At the same time, the first wall portion 211 also has good structural strength, reducing the risk of damage to the first wall portion 211. Therefore, the design of 0.3mm≤L≤20mm can enable the first wall portion 211 to better take into account the structural strength, connection strength and flow area at the same time, effectively improving the reliability of the battery cell 20.

[0146] In another embodiment of the present application, 5 mm ≤ L ≤ 10 mm.

[0147] By adopting the technical solution of this embodiment, the design of L≥5mm, the connecting groove 2112 has a reasonable groove width, the connecting groove 2112 has a reasonable flow area, and the second subspace 2103 can release pressure more quickly; the design of L≤10mm makes the area of ​​the connecting groove 2112 occupied by the first wall portion 211 within a more reasonable range, and the first wall portion 211 also has a more reasonable area to connect with the first pole ear 221, and the connection reliability between the first pole ear 221 and the first wall portion 211 is better. At the same time, the first wall portion 211 also has better structural strength, reducing the risk of damage to the first wall portion 211. Therefore, the design of 5mm≤L≤10mm can enable the first wall portion 211 to better take into account the structural strength, connection strength and flow area at the same time, effectively improving the reliability of the battery cell 20.

[0148] In one embodiment, the value of L may be, but is not limited to, any one of 0.3 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, or a value between any two of them.

[0149] In another embodiment of the present application, as shown in FIG. 8 to FIG. 10 , there are multiple communication channels 2111 , and the multiple communication channels 2111 are distributed at intervals along the circumferential direction Y of the first electrode tab 221 .

[0150] The number of the communication channels 2111 is greater than or equal to 2, and the plurality of communication channels 2111 are distributed at intervals along the circumferential direction Y of the first electrode tab 221 .

[0151] As an example, the connecting channel 2111 is a connecting groove 2112. As shown in Figures 8 and 10, the number of the connecting grooves 2112 is 3, and the 3 connecting grooves 2112 are evenly spaced along the circumferential direction Y of the first pole ear 221; as shown in Figure 9, the number of the connecting grooves 2112 is 2, and the 2 connecting grooves 2112 are evenly spaced along the circumferential direction Y of the first pole ear 221.

[0152] By adopting the technical solution of this embodiment, the first subspace 2102 and the second subspace 2103 are connected by multiple connecting channels 2111, and the emission medium in the second subspace 2103 can be discharged through the multiple connecting channels 2111, which is conducive to quickly achieving the internal air pressure balance of the battery cell 20; in addition, the multiple connecting channels 2111 are distributed at intervals along the circumferential Y direction of the first pole ear 221, so that the emission medium at any position in the second subspace 2103 can quickly reach the connecting channel 2111, thereby realizing the timely discharge of the emission medium in the second subspace 2103, and effectively improving the reliability of the battery cell 20.

[0153] In some cases, along the circumference of the first pole tab 221 , the first pole tab 221 and the first wall portion 211 are in a full circle; however, during the welding process, the distance between the first pole tab 221 and the first wall portion 211 gradually increases with the welding, resulting in poor welding quality between the first pole tab 221 and the first wall portion 211 .

[0154] In another embodiment of the present application, as shown in Figures 7 and 8, the first pole tab 221 is welded to the first wall portion 211 to form a first welding structure W1; the projection of the first welding structure W1 along the first direction and the projection of the connecting channel 2111 along the first direction do not overlap or partially overlap, wherein the first direction is the distribution direction of the first pole tab 221 and the first wall portion 211.

[0155] The first electrode tab 221 is welded to the first wall portion 211. It is understood that the first electrode tab 221 can be directly welded to the first wall portion 211. As an example, during welding, a laser is applied to the surface of the first wall portion 211 facing away from the first electrode tab 221, melting the material of the first wall portion 211 and the first electrode tab 221. After the material cools and solidifies, the first electrode tab 221 and the first wall portion 211 are welded together. The structure formed by the melting, cooling, and solidification of the material is the first welded structure W1. The first welded structure W1 serves as the connection structure W formed between the first electrode tab 221 and the first wall portion 211. Within the battery cell 20, the area located inside the first welded structure W1 is the first subspace 2102, and the area located outside the first welded structure W1 is the second subspace 2103.

[0156] The first electrode tab 221 and the first wall portion 211 are arranged along the thickness direction of the first wall portion 211 . The thickness direction Z of the first wall portion 211 is parallel to the first direction.

[0157] The projection of the first welding structure W1 along the first direction and the projection of the connecting channel 2111 along the first direction do not overlap or partially overlap. It is understood that along the circumferential direction Y of the first electrode tab 221, the first electrode tab 221 and the first wall portion 211 are welded in sections, avoiding at least a portion of the connecting channel 2111. That is, the portion of the first wall portion 211 provided with the connecting channel 2111 and the portion of the first wall portion 211 provided with the first welding structure W1 may partially overlap or completely not overlap. The first welding structure W1 may be a segmented structure along the circumferential direction Y of the first electrode tab 221, with the disconnected locations of the first welding structure W1 corresponding to the connecting channel 2111. The first welding structure W1 is disconnected at locations corresponding to the connecting channel 2111. Of course, other locations of the first welding structure W1 may also be disconnected.

[0158] By adopting the technical solution of this embodiment, the first pole tab 221 is directly welded to the first wall portion 211, and the assembly operation of the battery cell 20 is simple; in addition, the projection of the first welding structure W1 along the first direction and the projection of the connecting channel 2111 along the first direction do not overlap or partially overlap, so that the first pole tab 221 and the first wall portion 211 are welded in sections. On the one hand, the welding can avoid at least part of the connecting channel 2111, so that the first welding structure W1 will not close the connecting channel 2111, thereby realizing the connection between the first subspace 2102 and the second subspace 2103; on the other hand, the distance between the first pole tab 221 and the first wall portion 211 generated by the previous welding will not accumulate in the subsequent welding, thereby reducing the accumulation of the distance between the first pole tab 221 and the first wall portion 211, improving the welding quality of the first welding structure W1, and improving the reliability of the battery cell 20.

[0159] In some battery cells 20 , after the first pole tab 221 is flattened, the surface of the first pole tab 221 is uneven, and the first wall portion 211 is difficult to fit tightly with the first pole tab 221 . As a result, after the first pole tab 221 and the first wall portion 211 are welded, microcracks may occur in the first wall portion 211 , causing the sealing of the outer shell 21 to fail, thereby affecting the reliability of the battery cell 20 .

[0160] In another embodiment of the present application, in combination with Figures 6 and 8, the battery cell 20 also includes a first current collecting member 24 located between the first pole lug 221 and the first wall portion 211, and the first current collecting member 24 is connected to the first pole lug 221; the first current collecting member 24 is welded to the first wall portion 211 to form a second welding structure W2, and the projection of the second welding structure W2 along the first direction and the projection of the connecting channel 2111 along the first direction do not overlap or partially overlap, wherein the first direction is the distribution direction of the first pole lug 221 and the first wall portion 211.

[0161] The first current collector 24 may be a component connected between the first wall portion 211 and the first electrode tab 221. The first current collector 24 is made of a conductive material such as copper or aluminum to achieve electrical connection between the first electrode tab 221 and the first wall portion 211. The first current collector 24 has a plate-like structure, and its shape matches the shape of the first electrode tab 221. For example, when the first electrode tab 221 is cylindrical, the first current collector 24 is circular.

[0162] The first current collector 24 is located between the first wall portion 211 and the first electrode tab 221. One side of the first current collector 24 is connected to the first electrode tab 221 to achieve electrical connection between the first current collector 24 and the first electrode tab 221. The other side of the first current collector 24 is connected to the first wall portion 211 by welding to achieve electrical connection between the first electrode tab 221 and the first wall portion 211.

[0163] During assembly of the battery cell 20, the first current collector 24 is first connected to the first tab 221, and then the first wall 211 is welded to the first current collector 24. During the welding process, the materials of the first wall 211 and the first current collector 24 melt, cool, and solidify to form a second welded structure W2. The first current collector 24 and the first tab 221 can be connected by welding, bonding, or other methods.

[0164] When the first current collector 24 is welded to the first electrode tab 221, a third weld structure W3 is formed. The second weld structure W2 and the third weld structure W3 can be located in the same position or staggered. The third weld structure W3 serves as the connection structure W between the first electrode tab 221 and the first wall portion 211. Within the battery cell 20, the area inside the second weld structure W2 is the first subspace 2102, and the area inside the second weld structure W2 is the second subspace 2103.

[0165] The projection of the second weld structure W2 along the first direction and the projection of the connecting channel 2111 along the first direction do not overlap or partially overlap. It is understood that along the circumferential direction Y of the first electrode tab 221, the first current collector 24 is welded to the first wall portion 211 in sections to avoid at least part of the connecting channel 2111. That is, the portion of the first wall portion 211 provided with the connecting channel 2111 and the portion of the first wall portion 211 provided with the first weld structure W1 may partially overlap or completely not overlap. The second weld structure W2 may have a segmented structure along the circumferential direction Y of the first electrode tab 221, with the disconnected locations of the second weld structure W2 corresponding to the connecting channel 2111. The second weld structure W2 is disconnected at locations corresponding to the connecting channel 2111. Of course, other locations of the second weld structure W2 may also be disconnected.

[0166] By adopting the technical solution of this embodiment, the first wall portion 211 is connected to the first pole ear 221 through the first current collecting member 24, and the first wall portion 211 can be tightly welded to the first current collecting member 24, which can reduce the risk of microcracks in the first wall portion 211, and the sealing performance of the shell 21 is good, and the reliability of the battery cell 20 is good; and the first current collecting member 24 is welded to the first pole ear 221, and microcracks appear in the first current collecting member 24, which will not affect the sealing performance of the shell 21; in addition, similarly, the projection of the second welding structure W2 along the first direction and the projection of the connecting channel 2111 along the first direction do not overlap or partially overlap. The overlap allows the first current collecting part 24 and the first wall portion 211 to be welded in sections. On the one hand, the welding can avoid at least part of the connecting channel 2111, so that the second welding structure W2 will not close the connecting channel 2111, thereby realizing the connection between the first subspace 2102 and the second subspace 2103; on the other hand, the distance between the first current collecting part 24 and the first wall portion 211 generated by the previous welding will not accumulate in the subsequent welding, thereby reducing the accumulation of the distance between the first current collecting part 24 and the first wall portion 211, improving the welding quality of the second welding structure W2, and improving the reliability of the battery cell 20.

[0167] In another embodiment of the present application, as shown in FIG. 13 , a marking structure 2114 is provided on a surface of the first wall portion 211 facing away from the first electrode tab 221 . The marking structure 2114 is used to mark the position of the connecting channel 2111 .

[0168] The identification structure 2114 may be a structure disposed on the surface of the first wall portion 211 facing away from the first tab 221 and used to identify the location of the communication channel 2111. The identification structure may be disposed opposite the communication channel 2111 so that the identification structure can clearly indicate the location of the communication channel 2111. The identification structure may also be disposed offset relative to the communication channel 2111. For example, the identification structure may be an arrow pointing to the location of the communication channel 2111.

[0169] By adopting the technical solution of this embodiment, during the welding process between the first wall portion 211 and the first current collecting member 24 or the first pole ear 221, welding can be performed avoiding the connecting channel 2111 according to the identification structure, thereby reducing the risk of the connecting channel 2111 being closed, and the connection between the first subspace 2102 and the second subspace 2103 is reliable and stable, the pressure relief of the battery cell 20 is timely, and the battery cell 20 has good reliability in use.

[0170] In another embodiment of the present application, please refer to FIG. 13 , the identification structure 2114 includes at least one of an identification protrusion 21141 , an identification groove, a sticker, and a steel stamp.

[0171] It can be understood that the identification structure 2114 includes any one of the identification protrusion 21141, the identification groove, the sticker and the steel stamp, or the identification structure 2114 includes any two of the identification protrusion 21141, the identification groove, the sticker and the steel stamp, or the identification structure 2114 includes any three of the identification protrusion 21141, the identification groove, the sticker and the steel stamp, or the identification structure 2114 includes the identification protrusion 21141, the identification groove, the sticker and the steel stamp, where the identification protrusion 21141 may refer to a protruding structure formed by the surface of the first wall portion 211 facing away from the first pole ear 221, and the identification The protrusion 21141 may be disposed opposite the support protrusion 2113 and located on opposite sides of the first wall portion 211. The identification groove may be a groove structure formed by a depression on the surface of the first wall portion 211 facing away from the first electrode tab 221. The identification groove may be disposed opposite the support protrusion 2113 and located on opposite sides of the first wall portion 211. The sticker may be a piece of identification paper affixed to the surface of the first wall portion 211 facing away from the first electrode tab 221. The shape of the sticker may be adapted to the shape of the connecting channel 2111 to better identify the location of the connecting channel 2111. For example, the sticker may be a long sticker, a circular sticker, a fan-shaped sticker, etc. The steel stamp may be a mark left by embossing on the surface of the first wall portion 211 facing away from the first electrode tab 221.

[0172] By adopting the technical solution of this embodiment, the identification structure 2114 can be flexibly set to meet different production requirements.

[0173] In another embodiment of the present application, please refer to Figures 5 to 7. The first wall portion 211 includes a main body 2115 and a protrusion 2116 connected to the main body 2115. The protrusion 2116 is protruded relative to the surface of the main body 2115 toward the first pole ear 221, and the protrusion 2116 is arranged around the main body 2115; the connecting channel 2111 is provided on the protrusion 2116, and the pressure relief mechanism 23 is provided on the main body 2115. The protrusion 2116 is abutted against and connected to the first pole ear 221. A pressure relief gap 2104 for communicating with the connecting channel 2111 is formed between the main body 2115 and the first pole ear 221, and the pressure relief gap 2104 is located in the first subspace 2102.

[0174] The main body 2115 may refer to the main portion of the first wall portion 211 . The pressure relief mechanism 23 is provided on the main body 2115 . The pressure relief mechanism 23 and the main body 2115 may be an integral structure or a separate structure. The pressure relief mechanism 23 may be installed on the main body 2115 .

[0175] The protrusion 2116 may refer to the portion of the first wall portion 211 that protrudes from the main body 2115 toward the surface of the first pole ear 221. The protrusion 2116 is annular and is arranged on the outside of the main body 2115. The first pole ear 221 and the surface of the protrusion 2116 facing the first pole ear 221 are abutted and connected. The space inside the protrusion 2116 is the pressure relief gap 2104, and the pressure relief gap 2104 is located between the first pole ear 221 and the main body 2115.

[0176] As an example, in combination with Figure 7, when the first pole tab 221 is directly welded to the protrusion 2116, the first pole tab 221 and the protrusion 2116 protrude from the body 2115 toward the surface of the first pole tab 221 and are welded, the protrusion 2116 lifts the first pole tab 221, and a pressure relief gap 2104 is formed between the first pole tab 221 and the body 2115; in combination with Figures 5 and 6, when the protrusion 2116 is welded to the first current collecting member 24, the first current collecting member 24 and the protrusion 2116 protrude from the body 2115 toward the surface of the first pole tab 221 and are welded, the protrusion 2116 lifts the first current collecting member 24, and a pressure relief gap 2104 is formed between the body 2115 and the first current collecting member 24.

[0177] The pressure relief gap 2104 is also part of the first subspace 2102, and the pressure relief mechanism 23 is located in the main body 2115, so that the discharge medium in the pressure relief gap 2104 can be directly discharged quickly through the pressure relief mechanism 23, thereby releasing the internal pressure of the pressure relief gap 2104; the connecting channel 2111 is located in the convex portion 2116, so that one end of the connecting channel 2111 can be directly connected to the second subspace 2103, and the other end of the connecting channel 2111 can be directly connected to the pressure relief gap 2104, so that the discharge medium in the second subspace 2103 can enter the pressure relief gap 2104 through the connecting channel 2111, and then be discharged through the pressure relief mechanism 23.

[0178] By adopting the technical solution of this embodiment, the discharge medium of the second subspace 2103 enters the pressure relief gap 2104 through the connecting channel 2111, and can quickly flow to the pressure relief mechanism 23 through the pressure relief gap 2104, and finally be discharged through the pressure relief mechanism 23, so that the internal pressure balance of the battery cell 20 can be achieved more quickly, thereby improving the reliability of the use of the battery cell 20; in addition, the pressure relief gap 2104 can provide an actuation space for the pressure relief mechanism 23, and the pressure relief mechanism 23 can be actuated in time to relieve pressure, thereby improving the timeliness of the pressure relief of the battery cell 20.

[0179] In one embodiment, the first wall portion 211 also includes an extension portion 2117, which surrounds the side of the protrusion 2116 facing away from the main body 2115. The extension portion 2117 covers the end face of the shell 213 to close the opening of the shell 213. The extension portion 2117 and the shell 213 can be sealed and connected by welding, flanging, etc.

[0180] In another embodiment of the present application, in combination with Figures 4 and 5, the outer shell 21 includes a shell 213 and an end cover 212, the end cover 212 covers the opening of the shell 213, and the end cover 212 and the shell 213 are jointly arranged to form an accommodating space 2101; the end cover 212 is the first wall portion 211; or, the wall portion of the shell 213 is the first wall portion 211.

[0181] The housing 213 may be a hollow structure with one end open. The end cap 212 covers the opening at the end of the housing 213, thereby sealing the housing 213. The housing 213 and the end cap 212 together enclose the accommodation space 2101. The end cap 212 and the housing 213 may be connected by welding, flanging, or other methods to enclose the electrode assembly 22 in the accommodation space 2101.

[0182] As an example, the end cap 212 is the first wall portion 211, that is, the first electrode tab 221 is connected to the end cap 212, and the connecting groove 2112 is provided in the end cap 212; the end cap 212 is a plate-like structure made by processing a plate material. If the surface of the end cap 212 facing the first electrode tab 221 is flat, the connecting groove 2112 can be directly processed into the flat surface. If the surface of the end cap 212 facing the first electrode tab 221 is formed with a protrusion, the connecting groove 2112 can be processed into the surface with the protrusion facing the first electrode tab 221; the processing space for processing the connecting groove 2112 of the end cap 212 is large, which is conducive to improving production efficiency. Of course, in other embodiments, similarly, the first wall portion 211 can be a wall portion of the housing 213.

[0183] By adopting the technical solution of this embodiment, the electrode assembly 22 can be placed into the shell 213 through the opening of the shell 213, and then the opening of the shell 213 is closed by the end cover 212. In this way, the electrode assembly 22 is encapsulated in the outer shell 21. The assembly operation is simple, which is conducive to improving the production efficiency of the battery cell 20.

[0184] In another embodiment of the present application, as shown in Figures 4 and 5, the electrode assembly 22 further has a second pole ear 222, which is located on the side of the electrode assembly 22 facing away from the first wall portion 211, and the polarity of the first pole ear 221 is opposite to the polarity of the second pole ear 222; the battery cell 20 also includes an electrode terminal 25 and a first insulating member 26, the outer shell 21 has a second wall portion 214 arranged opposite to the first wall portion 211, and the second wall portion 214 is provided with an electrode lead-out hole 2141 connected to the accommodating space 2101, the first insulating member 26 is sleeved on the outside of the electrode terminal 25, and the first insulating member 26 is passed through the electrode lead-out hole 2141 to insulate and separate the electrode terminal 25 and the outer shell 21; the second pole ear 222 is connected to the electrode terminal 25 to make the second pole ear 222 electrically connected to the electrode terminal 25.

[0185] The second electrode tab 222 may refer to a tab provided at the end of the electrode assembly 22 facing away from the first electrode tab 221 ; the polarity of the first electrode tab 221 is opposite to the polarity of the second electrode tab 222 , and one of the first electrode tab 221 and the second electrode tab 222 is a positive electrode tab and the other is a negative electrode tab.

[0186] The electrode terminal 25 may refer to a component used to electrically connect to the second electrode tab 222 for outputting or inputting electrical energy into the battery cell 20. The electrode terminal 25 is made of a conductive material to achieve input and output of electrical energy. The electrode terminal 25 may be, but is not limited to, copper, aluminum, etc. The shape of the electrode terminal 25 may be, but is not limited to, a cylinder, a prism, etc.

[0187] The first insulating member 26 is a component used to insulate the electrode terminal 25 from the outer shell 21. The first insulating member 26 is made of an insulating material to meet insulation requirements, such as plastic or rubber. Because the first tab 221 is connected to the outer shell 21, the first tab 221 and the outer shell 21 have the same charge. Simultaneously, the second tab 222 is connected to the electrode terminal 25, and the electrode terminal 25 and the second tab 222 have the same charge. However, the first insulating member 26 insulates the electrode terminal 25 from the outer shell 21, effectively isolating the first tab 221 and the second tab 222, thereby reducing the risk of short circuits.

[0188] The second wall portion 214 may refer to a wall portion of the housing 21 opposite the first wall portion 211. The second wall portion 214 may be the end cap 212 or a wall portion of the casing 213. As an example, the first wall portion 211 may be the end cap 212, and the second wall portion 214 may be a wall portion of the casing 213 opposite the end cap 212. Alternatively, the first wall portion 211 and the second wall portion 214 may be two opposite walls of the casing 213.

[0189] The electrode lead-out hole 2141 may refer to a through hole provided in the second wall portion 214 for communicating with the accommodation space 2101 , and the electrode terminal 25 may pass through the electrode lead-out hole 2141 to input or output electrical energy of the battery cell 20 .

[0190] The first insulating member 26 is sleeved on the outside of the electrode terminal 25 and extends through the electrode lead-out hole 2141, so that the electrode terminal 25 is insulated and separated from the periphery of the electrode lead-out hole 2141 by the first insulating member 26, thereby achieving insulation between the electrode terminal 25 and the housing 21. As an example, a mounting groove is defined on the outer periphery of the electrode terminal 25, and the first insulating member 26 is installed in the mounting groove. A fixing groove is defined on the periphery of the first insulating member 26 facing away from the electrode assembly 22, and the periphery of the electrode lead-out hole 2141 is inserted into the fixing groove, thereby achieving insulation between the electrode terminal 25 and the second wall portion 214.

[0191] By adopting the technical solution of this embodiment, the housing 21 serves as one output stage of the battery cell 20 , and the electrode terminal 25 serves as another output stage of the battery cell 20 . The housing 21 and the electrode terminal 25 are connected to an external circuit to realize charging and discharging of the battery cell 20 .

[0192] In another embodiment of the present application, in combination with Figures 4 and 5, the electrode assembly 22 also includes a second current collecting member 27 and a second insulating member 28. The second current collecting member 27 is connected between the second pole tab 222 and the electrode terminal 25 to achieve electrical connection between the second pole tab 222 and the electrode terminal 25; at least a portion of the second insulating member 28 is located between the second current collecting member 27 and the second wall portion 214.

[0193] The second current collector 27 is a component connected between the electrode terminal 25 and the second tab 222. The second current collector 27 and the second tab 222, as well as the second current collector 27 and the electrode terminal 25, can be connected by welding, bonding, or other methods to achieve electrical connection between the electrode terminal 25 and the second tab 222. The second current collector 27 is made of a conductive material such as copper or aluminum to meet electrical conductivity requirements. The material of the second current collector 27 can be the same as or different from that of the first current collector 24. The second current collector 27 has a plate-like structure, and its shape matches the shape of the second tab 222. For example, if the second tab 222 is circular, the second current collector 27 is also circular. The structure of the second current collector 27 can be the same as or different from that of the first current collector 24.

[0194] The second insulating member 28 is located between the second current collecting member 27 and the second wall portion 214 and is made of an insulating material such as plastic or rubber. The first insulating member 26 can be made of the same material as the second insulating member 28. The second insulating member 28 is sandwiched between the second current collecting member 27 and the second wall portion 214 to insulate the second current collecting member 27 from the housing 21. Among them, the second insulating member 28 can be completely clamped between the second current collecting member 27 and the second wall portion 214; or, a portion of the second insulating member 28 can be clamped between the second current collecting member 27 and the second wall portion 214, and the other portion can be clamped between the electrode terminal 25 and the first wall portion 211; as an example, the second insulating member 28 is located in the accommodating space 2101, the second insulating member 28 is sleeved outside the electrode terminal 25, the inner peripheral side of the second insulating member 28 is clamped between the electrode terminal 25 and the second wall portion 214, and the outer peripheral side of the second insulating member 28 is clamped between the electrode terminal 25 and the second current collecting member 27, so as to completely insulate and separate the electrode terminal 25 and the second current collecting member 27 from the outer shell 21; of course, the second insulating member 28 can also be completely clamped between the second current collecting member 27 and the second wall portion 214.

[0195] By adopting the technical solution of this embodiment, the second pole tab 222 is connected to the electrode terminal 25 through the second current collector 27. The second current collector 27 can support the second pole tab 222 and the electrode terminal 25, thereby improving the connection stability between the second pole tab 222 and the electrode terminal 25, and helping to improve the reliability of the battery cell 20. In addition, the second insulating member 28 can insulate and separate the second current collector 27 from the outer shell 21, thereby reducing the risk of short circuit.

[0196] In another embodiment of the present application, as shown in Figures 4 and 5, the battery cell 20 also includes a sealant 29, and the electrode terminal 25 is constructed with an injection hole 251 connected to the accommodating space 2101. The sealant 29 covers the opening of the injection hole 251 facing away from the electrode assembly 22 to seal the injection hole 251.

[0197] The injection hole 251 may refer to a through hole in the electrode terminal 25 that communicates with the accommodation space 2101. The injection hole 251 may connect the exterior of the battery cell 20 and the accommodation space 2101 to allow electrolyte to be injected into the accommodation space 2101. As an example, the injection hole 251 may penetrate the electrode terminal 25 along the axis of the electrode terminal 25.

[0198] The seal 29 may refer to a component that seals the liquid injection hole 251; after the liquid injection is completed, the seal 29 seals and covers the opening of the liquid injection hole 251 facing away from the electrode assembly 22, so that the liquid injection hole 251 is closed, reducing the risk of electrolyte leakage in the battery cell 20; the seal 29 may be made of stainless steel, galvanized steel, copper, aluminum and other materials; the seal 29 may be a stud, a sealing nail and other structural forms, and the seal 29 may seal the liquid injection hole 251 by welding, pressing, bonding and the like.

[0199] By adopting the technical solution of this embodiment, the provision of the injection hole 251 can realize the injection of liquid into the battery cell 20, and the sealing member 29 can seal the injection hole 251, thereby reducing the risk of electrolyte leakage.

[0200] In one embodiment, in combination with Figures 4 and 5, when the electrode assembly 22 is a winding structure, the electrode assembly 22 has a center hole 223 at its center position, and the center hole 223 is formed after the winding needle is pulled out from the electrode assembly 22. The injection hole 251 passes through the electrode terminal 25 and is coaxially arranged with the center hole 223. The first current collecting part 24 is provided with a first connecting hole 241 at a position opposite to the injection hole 251. The first connecting hole 241 connects the injection hole 251 and the center hole 223. The second current collecting part 27 is provided with a second connecting hole 271 at a position opposite to the center hole 223. The second connecting hole 271 connects the center hole 223 and the pressure relief gap 2104.

[0201] During the injection process, after the electrolyte is injected from the injection hole 251, it flows into the center hole 223 through the first connecting hole 241 under the action of its own gravity, and infiltrates the electrode assembly 22 from the center position of the electrode assembly 22 through the center hole 223, and the infiltration effect of the electrode assembly 22 is good; at the same time, the electrolyte can also enter the pressure relief gap 2104 through the second through hole, thereby flowing to the bottom of the electrode assembly 22, and the electrolyte can better infiltrate the electrode assembly 22.

[0202] The battery cell 20 of the present application is described below with reference to some embodiments.

[0203] Example 1

[0204] In this embodiment, as shown in Figures 3 to 6 and 8, the battery cell 20 includes a shell 21, an electrode assembly 22 and a pressure relief mechanism 23. The shell 21 has a accommodating space 2101 and a first wall portion 211; the electrode assembly 22 is located in the accommodating space 2101, and the electrode assembly 22 has a first electrode tab 221. The first electrode tab 221 is located on the side of the electrode assembly 22 facing the first wall portion 211, and the first electrode tab 221 is connected to the first wall portion 211 to form a first subspace 2102 and a second subspace 2103 in the accommodating space 2101; the pressure relief mechanism 23 is provided in the shell 21, and the pressure relief mechanism 23 is used to actuate when the internal pressure of the first subspace 2102 reaches a threshold value to release the internal pressure of the first subspace 2102; wherein the first wall portion 211 is constructed with a connecting channel 2111, and the connecting channel 2111 connects the first subspace 2102 and the second subspace 2103.

[0205] In this embodiment, the shell 21 includes an end cover 212 and the shell 21, the shell 213 is a hollow component with an opening at one end, and the end cover 212 covers the opening at the end of the shell 213 to enclose and form a accommodating space 2101; the end cover 212 is a first wall portion 211, and the end cover 212 includes a main body 2115 and a protrusion 2116, the protrusion 2116 protrudes from the surface of the main body 2115 toward the first pole ear 221, and the protrusion 2116 surrounds the outer peripheral side of the main body 2115.

[0206] In this embodiment, the battery cell 20 further includes a first current collector 24. The communication channel 2111 is a protrusion 2116 with a communication groove 2112 formed on the surface of the first electrode tab 221. One side of the first current collector 24 abuts and is welded to the portion of the protrusion not provided with the communication groove 2112 to form a second weld structure W2. The second weld structure W2 is a multi-segment structure surrounding the central axis X of the electrode assembly 22. The other side of the first current collector 24 abuts and is welded to the first electrode tab 221 to form a third weld structure W3. The second and third weld structures W2 and W3 are staggered, with the third weld structure W3 being closer to the central axis X of the electrode assembly 22 than the second weld structure W2. Within the accommodating space 2101, the area inside the second weld structure W2 is the first subspace 2102, and the area outside the second weld structure W2 is the second subspace 2103. The gap between the first current collecting member 24 and the main body 2115 forms a pressure relief gap 2104 . The pressure relief gap 2104 is located inside the protrusion 2116 and also inside the second welding structure W2 . The pressure relief gap 2104 is part of the first subspace 2102 .

[0207] In this embodiment, the connecting groove 2112 is a rectangular groove extending radially through the protrusion 2116 of the first electrode tab 221. There are three connecting grooves 2112, which are evenly spaced along the circumferential direction Y of the first electrode tab 221. Accordingly, the second welding structure W2 is divided into three sections, each of which is located between two adjacent connecting grooves 2112.

[0208] In this embodiment, the pressure relief mechanism 23 is provided on the body 2115 , and the pressure relief mechanism 23 is an annular groove 231 formed on the surface of the body 2115 facing the first electrode tab 221 .

[0209] In this embodiment, the end cover 212 further includes an extension portion 2117 . The extension portion 2117 surrounds the outer side of the protrusion 2116 facing away from the body 2115 . The extension portion 2117 is welded to the opening of the shell 213 .

[0210] In this embodiment, the battery cell 20 further includes a second current collector 27, an electrode terminal 25, a first insulating member 26 and a second insulating member 28; the electrode assembly 22 further includes a second pole ear 222, which is located at the end of the electrode assembly 22 facing away from the first pole ear 221, and the polarity of the first pole ear 221 is opposite to the polarity of the second pole ear 222; the wall portion of the shell 213 opposite to the end cover 212 is a second wall portion 214, and the second wall portion 214 is provided with an electrode lead-out hole 2141, and one side of the second current collector 27 is connected to the second pole ear 222, and the second pole ear 222 is connected to the second pole ear 222. The other side of the second current collecting member 27 is connected to the electrode terminal 25. The electrode terminal 25 is covered with a first insulating member 26. The first insulating member 26 is passed through the electrode lead-out hole 2141 to insulate and separate the electrode terminal 25 from the second wall portion 214. A portion of the second insulating member 28 is located between the second current collecting member 27 and the second wall portion 214, and another portion of the second insulating member 28 is located between the electrode terminal 25 and the second wall portion 214 to achieve insulation separation between the electrode terminal 25 and the second wall portion 214 and between the second current collecting member 27 and the second wall portion 214.

[0211] In this embodiment, the electrode terminal 25 is provided with an injection hole 251, and the center position of the electrode assembly 22 is provided with a center hole 223. The center hole 223 is formed after the winding needle is pulled out from the electrode assembly 22. The injection hole 251 passes through the electrode terminal 25 and is coaxially arranged with the center hole 223. The first current collector 24 is provided with a first connecting hole 241 at a position opposite to the injection hole 251. The first connecting hole 241 connects the injection hole 251 and the center hole 223. The second current collector 27 is provided with a second connecting hole 271 at a position opposite to the center hole 223. The second connecting hole 271 connects the center hole 223 and the pressure relief gap 2104. The opening cover of the injection hole 251 facing away from the second electrode ear 222 is provided with a sealing member 29 to seal the injection hole 251.

[0212] Example 2

[0213] The difference between this embodiment and the first embodiment is that, as shown in FIG. 7 , the battery cell 20 does not include the first current collector 24 , and the first electrode tab 221 is directly welded to the protrusion 2116 to form a first welding structure W1 .

[0214] Example 3

[0215] The difference between this embodiment and the above-mentioned embodiment 1 is that: as shown in Figure 9, the connecting groove 2112 is a fan-shaped groove that penetrates the protrusion 2116 along the radial direction of the first pole tab 221, and the number of the connecting grooves 2112 is 2. The two connecting grooves 2112 are evenly spaced along the circumferential direction Y of the first pole tab 221. Correspondingly, the second welding structure W2 is divided into two sections, and each section of the welding structure is located between two adjacent connecting grooves 2112.

[0216] Example 4

[0217] The difference between this embodiment and the above-mentioned embodiment three is that: as shown in Figures 10 to 12, the connecting groove 2112 is a fan-shaped groove that penetrates the protrusion 2116 along the radial direction of the first pole tab 221, and the number of connecting grooves 2112 is 3. The 3 connecting grooves 2112 are evenly spaced along the circumferential direction Y of the first pole tab 221. Correspondingly, the second welding structure W2 is divided into three sections, and each section of the welding structure is located between two adjacent connecting grooves 2112.

[0218] In this embodiment, a support protrusion 2113 is configured on the wall surface of the connecting groove 2112 opposite the first electrode tab 221. The support protrusion 2113 is used to support the first current collector 24, preventing the first current collector 24 from entering the connecting groove 2112, and reducing the risk of the connecting groove 2112 being blocked. There are multiple support protrusions 2113, and the multiple support protrusions 2113 are evenly spaced and distributed on the wall surface of the connecting groove 2112 opposite the first electrode tab 221.

[0219] Example 5

[0220] The difference between this embodiment and the above-mentioned embodiment 4 is that: as shown in Figure 13, the surface of the protrusion 2116 facing away from the first pole ear 221 is constructed with an identification structure 2114, and the identification structure 2114 is used to identify the position of the connecting groove 2112. The identification structure 2114 is an identification protrusion 21141 formed on the surface of the protrusion 2116 facing away from the first pole ear 221. The identification protrusion 21141 and the connecting groove 2112 are arranged opposite to each other. There are multiple identification protrusions 21141, and the multiple identification protrusions 21141 are evenly spaced and distributed on the surface of the protrusion 2116 facing away from the first pole ear 221.

[0221] In another embodiment of the present application, a battery 1100 is provided, comprising the battery cell 20 according to the above embodiment.

[0222] The battery 1100 of the embodiment of the present application adopts the above-mentioned battery cell 20. The battery cell 20 has good reliability in use, thereby improving the reliability and performance of the battery 1100.

[0223] In another embodiment of the present application, an electrical device is provided, comprising the battery 1100 according to the above embodiment.

[0224] The electrical device of the embodiment of the present application adopts the above-mentioned battery 1100. The battery 1100 has good reliability and performance, thereby improving the reliability and performance of the electrical device.

[0225] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0226] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. 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. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include, A housing having a receiving space and a first wall portion; an electrode assembly, located in the accommodation space, the electrode assembly having a first electrode tab, the first electrode tab being located on a side of the electrode assembly facing the first wall portion, the first electrode tab being connected to the first wall portion, and dividing the accommodation space into a first subspace and a second subspace; a pressure relief mechanism, disposed on the housing, and configured to be actuated when the internal pressure of the first subspace reaches a threshold value to release the internal pressure of the first subspace; The first wall portion is configured with a connecting passage, and the connecting passage connects the first subspace and the second subspace.

2. The battery cell according to claim 1, characterized in that: The communication channel includes a communication groove formed on a surface of the first wall portion facing the first electrode tab, one end of the communication groove is communicated with the first subspace, and the other end of the communication groove is communicated with the second subspace.

3. The battery cell according to claim 2, characterized in that: A supporting protrusion is formed on a groove wall surface of the communicating groove facing the first electrode tab.

4. The battery cell according to claim 3, characterized in that: The supporting protrusion protrudes out of the communicating groove.

5. The battery cell according to any one of claims 2 to 4, characterized in that: The groove depth of the connecting groove is T1, and the wall thickness of the first wall portion is T2, wherein 0.3≤T1 / T2≤0.

6.

6. The battery cell according to claim 5, characterized in that: 0.4≤T1 / T2≤0.

5.

7. The battery cell according to any one of claims 2 to 6, characterized in that: The first wall portion is circular, the width of the connecting groove is L, and the diameter of the first wall portion is D, wherein 0<L / D≤0.

1.

8. The battery cell according to claim 7, characterized in that: 0.001≤L / D≤0.

05.

9. The battery cell according to any one of claims 2 to 8, characterized in that: The groove depth of the connecting groove is T1, wherein 0.1 mm≤T1≤0.6 mm.

10. The battery cell according to claim 9, characterized in that: 0.3mm≤T1≤0.5mm.

11. The battery cell according to any one of claims 2 to 10, characterized in that: The groove width of the connecting groove is L, wherein 0.3mm≤L≤20mm.

12. The battery cell according to claim 11, characterized in that: 5mm≤L≤10mm.

13. The battery cell according to any one of claims 1 to 12, characterized in that: There are multiple communication channels, and the multiple communication channels are distributed at intervals along the circumference of the first electrode lug.

14. The battery cell according to any one of claims 1 to 13, characterized in that: The first electrode tab is welded to the first wall portion to form a first welding structure; A projection of the first welding structure along a first direction and a projection of the connecting channel along the first direction do not overlap or partially overlap; wherein the first direction is a distribution direction of the first electrode tab and the first wall portion.

15. The battery cell according to any one of claims 1 to 14, characterized in that: The battery cell further includes a first current collector located between the first pole tab and the first wall portion, the first current collector being connected to the first pole tab; the first current collector is welded to the first wall portion to form a second welding structure; The projection of the second welding structure along the first direction and the projection of the connecting channel along the first direction do not overlap or wherein the first direction is the distribution direction of the first pole ear and the first wall portion.

16. The battery cell according to any one of claims 1 to 15, characterized in that: A marking structure is provided on a surface of the first wall portion facing away from the first electrode tab, and the marking structure is used to mark the position of the connecting channel.

17. The battery cell according to claim 16, characterized in that: The identification structure includes at least one of an identification protrusion, an identification groove, a sticker and a steel stamp.

18. The battery cell according to any one of claims 1 to 17, characterized in that: The first wall portion includes a main body and a convex portion, the convex portion is protruding relative to the surface of the main body facing the first pole ear, the convex portion is arranged around the main body, the connecting channel is arranged on the convex portion, the pressure relief mechanism is arranged on the main body, the convex portion is abutted against and connected to the first pole ear, and a pressure relief gap for communicating with the connecting channel is formed between the main body and the first pole ear, and the pressure relief gap is located in the first subspace.

19. The battery cell according to any one of claims 1 to 18, characterized in that: The housing includes a shell and an end cover, wherein the end cover covers an opening of the shell, and the end cover and the shell are jointly arranged to form the accommodating space, and the end cover is the first wall portion; or, the wall portion of the shell is the first wall portion.

20. The battery cell according to any one of claims 1 to 19, characterized in that: The electrode assembly further comprises a second electrode tab, which is located on a side of the electrode assembly facing away from the first wall portion, and the polarity of the first electrode tab is opposite to the polarity of the second electrode tab; The battery cell also includes an electrode terminal and a first insulating member. The outer shell has a second wall portion arranged opposite to the first wall portion, and the second wall portion is provided with an electrode lead-out hole connected to the accommodating space. The first insulating member is sleeved on the outside of the electrode terminal, and the first insulating member is passed through the electrode lead-out hole to insulate and separate the electrode terminal from the outer shell; the second pole ear is connected to the electrode terminal to electrically connect the second pole ear to the electrode terminal.

21. The battery cell according to claim 20, characterized in that: The electrode assembly further includes a second current collector and a second insulating member, wherein the second current collector is connected between the second electrode tab and the electrode terminal to achieve electrical connection between the second electrode tab and the electrode terminal; At least a portion of the second insulating member is located between the second current collecting member and the second wall portion.

22. The battery cell according to claim 20 or 21, characterized in that: The battery cell further includes a sealing member, the electrode terminal is configured with a liquid injection hole communicating with the accommodation space, and the sealing member covers an opening of the liquid injection hole facing away from the electrode assembly to seal the liquid injection hole.

23. A battery, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 22.

24. An electrical device, characterized in that: Comprising the battery of claim 23.

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