Battery monomer, battery and electric device

Abstract

The utility model discloses a battery monomer, a battery and a power utilization device. The battery monomer comprises an electrode assembly and a battery pack, the shell is used for accommodating the electrode assembly, the shell is provided with a nick groove, the nick groove defines a preset pressure relief area which is opened during pressure relief of the battery monomer, the shell is provided with a redundant part which is arched towards one side close to and / or far away from the electrode assembly, and the redundant part is provided with a plurality of pressure relief holes. And the redundant part is positioned on one side, far away from the geometric center of the preset pressure relief area, of the nick groove. According to the technical scheme, the redundant part is arranged on the outer side of the nick groove, when the electrode assembly expands, the expansive force of the electrode assembly can pull the redundant part to enable the redundant part to deform to a certain degree, and therefore the redundant part absorbs at least part of the expansive force of the electrode assembly, the expansive force acting on the nick groove is reduced, and the reliability of the electrode assembly is improved. And the pulling force on the nick groove is reduced, so that the probability of liquid leakage caused by pulling damage of the nick groove can be reduced, and the service life and the reliability of the battery monomer are improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] In order to ensure the safety performance of the battery cell, a pressure relief part is usually provided on the battery cell. The pressure relief part is used to release the pressure inside the battery cell when the battery cell reaches a predetermined condition. During the charge and discharge process of the battery cell, the electrode assembly will expand and deform, causing the outer shell accommodating the electrode assembly to swell and deform, which in turn makes the pressure relief part provided on the outer shell easy to be damaged, reducing the reliability of the battery cell. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can alleviate the problem of damage occurring at the notched groove during battery use.

[0005] In a first aspect, the present application provides a battery cell, comprising: an electrode assembly; a shell for accommodating the electrode assembly, the shell being provided with a notched groove, the notched groove defining a predetermined pressure relief zone that opens when the battery cell is depressurized; wherein the shell is provided with a redundant portion that arches toward a side close to and / or away from the electrode assembly, and the redundant portion is located outside the predetermined pressure relief zone.

[0006] In the technical solution of the embodiment of the present application, a redundant portion is arranged on the outside of a predetermined pressure relief area. When the electrode assembly expands, the expansion force of the electrode assembly can pull the redundant portion, causing a certain deformation of the redundant portion. The redundant portion absorbs at least part of the expansion force of the electrode assembly, thereby reducing the expansion force acting on the notched groove, reducing the pulling force on the notched groove, and reducing the probability of the notched groove being pulled and damaged, resulting in leakage, thereby improving the service life and reliability of the battery cell.

[0007] In some embodiments, the shell is provided with a thinning area, the minimum thickness of the thinning area is greater than the maximum thickness at the notch groove and the maximum thickness of the thinning area is less than the maximum thickness of the wall of the shell where the thinning area is located, and a part of the thinning area is arched toward and / or away from the side of the electrode assembly to form the redundant part. In the above technical solution, by setting the thinning area, the thinning area is more likely to deform, and the redundant part is set in the thinning area, so that the redundant part is deformed under the action of the expansion force of the electrode assembly and is pulled and unfolded. Since the thickness of the thinning area is greater than the maximum thickness at the notch groove, the redundant part is pulled due to the thickness being too small, and the probability of leakage can be avoided. At the same time, it is ensured to a certain extent that the notch groove is the weakest position of the entire battery cell, so that when the internal pressure of the battery cell reaches the threshold, the internal pressure of the battery cell is released at a predetermined position to achieve the purpose of pressure relief at a specific position.

[0008] In some embodiments, the notched groove is provided in the thinning area. In the above technical solution, when the electrode assembly expands, the expansion force of the electrode assembly can preferentially pull the redundant part, causing the redundant part to deform to a certain extent, absorbing at least part of the expansion force of the electrode assembly, and reducing the expansion force acting on the notched groove. It can also avoid the possibility of leakage caused by the redundant part being pulled due to the thickness being too small, and the notched groove can be made the weakest position of the entire battery cell, so that when the internal pressure of the battery cell reaches the threshold, the internal pressure of the battery cell is released at a predetermined position, thereby achieving the purpose of pressure relief at a specific position.

[0009] In some embodiments, the maximum height dimension of the redundant part is H in the direction close to and / or away from the electrode assembly, and the maximum width dimension of the redundant part is W in the direction away from the notch groove, and 0.03≤H / W≤10. In the above technical solution, it is convenient to manufacture and form the redundant part, and when the electrode assembly expands, the redundant part can undergo a certain deformation to absorb at least part of the expansion force of the electrode assembly, reduce the expansion force acting on the notch groove, reduce the probability of the notch groove being pulled and damaged, resulting in leakage, and improve the service life and reliability of the battery cell.

[0010] In some embodiments, along the direction approaching and / or away from the electrode assembly, the maximum height dimension of the redundant part is H, 0.1mm≤H≤2mm. In the above technical solution, it is convenient to manufacture and form the redundant part, and it will not cause a significant impact on other structural parts. At the same time, the redundant part can undergo a certain deformation when the electrode assembly expands, absorbing at least part of the expansion force of the electrode assembly, thereby reducing the expansion force acting on the notched groove, reducing the probability of the notched groove being pulled and damaged, resulting in leakage, and improving the service life and reliability of the battery cell.

[0011] In some embodiments, along the direction away from the notch groove, the maximum width dimension of the redundant part is W, 0.2mm≤W≤3mm. In the above technical solution, it is convenient to manufacture and form the redundant part, and it will not cause a significant impact on other structural parts, increase the area of ​​the predetermined pressure relief area, meet the exhaust requirements, improve the timeliness of the pressure relief part explosion, and improve the reliability of the battery cell.

[0012] In some embodiments, the redundant part extends along the periphery of the predetermined pressure relief zone, and the shape of the cross section of the redundant part perpendicular to the extension direction of the redundant part is an arc. In the above technical solution, the arc-shaped design is convenient for the manufacturing and forming of the redundant part, and the redundant part with an arc-shaped design is easier to be unfolded when the electrode assembly expands, avoiding the situation that the redundant part is difficult to unfold and deform due to the high bending hardness of the local bending part, so that the redundant part can undergo a certain deformation when the electrode assembly expands, absorb at least part of the expansion force of the electrode assembly, and alleviate the problem that the notched groove is pulled and damaged by the expansion force of the electrode assembly, resulting in leakage.

[0013] In some embodiments, the redundant parts are symmetrically arranged along the geometric center of the shell. In the above technical solution, the shell as a whole forms a symmetrical structure, which, on the one hand, facilitates the manufacture of the redundant parts, and on the other hand, enables the redundant parts to play the same buffering role for the notched grooves at various positions, thereby reducing the probability of the notched grooves being partially pulled and broken, and improving the reliability of the entire battery cell.

[0014] In some embodiments, the electrode assembly includes at least one positive electrode sheet and at least one negative electrode sheet, the at least one positive electrode sheet and the at least one negative electrode sheet are stacked to form a straight area, at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked in the straight area along a first direction, the housing includes a first wall portion, the first wall portion is located on one side of the electrode assembly in a second direction, the second direction is the thickness direction of the first wall portion and is perpendicular to the first direction, the first wall portion is provided with the notched groove and the redundant portion. In the above technical solution, by providing the redundant portion, the first wall portion can have more stretching at the redundant portion, and the redundant portion undergoes a certain deformation to absorb at least part of the expansion force of the electrode assembly, thereby reducing the expansion force acting on the notched groove, thereby reducing the stretching at the notched groove, reducing the probability of the notched groove being pulled and damaged, resulting in leakage, and improving the service life and reliability of the battery cell.

[0015] In some embodiments, the redundant portion includes a first redundant segment, and the first redundant segment is located on one side of the notched groove in the first direction. In the above technical solution, the first redundant segment is located on both sides of the front and rear of the notched groove. When the electrode assembly expands, the first wall portion is subjected to a large pulling force in the front and rear directions, which can be released to a certain extent at the first redundant segment. By pulling the first redundant segment to deform, the pulling force transmitted to the notched groove can be reduced, the probability of the notched groove being pulled and damaged can be reduced, the risk of leakage can be reduced, and the service life and reliability of the battery cell can be improved.

[0016] In some embodiments, the maximum length of the predetermined pressure relief zone in the third direction is L1, the maximum groove length of the first redundant segment in the third direction is L2, and the following conditions are satisfied: L2 / L1≥0.9, and the third direction is perpendicular to the first direction and the second direction, respectively. In the above technical solution, the pulling force on each position of the entire predetermined pressure relief zone is reduced to a certain extent, and by pulling the first redundant segment to deform and expand, a buffering effect can be played on each part where the notched groove is located, reducing the probability of the notched groove being pulled and damaged, resulting in leakage, and improving the service life and reliability of the battery cell.

[0017] In some embodiments, the redundant portion includes a second redundant segment, and the second redundant segment is located on one side of the notched groove in a third direction, and the third direction is perpendicular to the first direction and the second direction respectively. In the above technical solution, by providing the second redundant segment, the pulling force can be released to a certain extent at the second redundant segment, and by pulling the second redundant segment to deform and unfold, the pulling force transmitted to the notched groove can be reduced, the probability of the notched groove being pulled and damaged can be reduced, the risk of leakage can be reduced, and the service life and reliability of the battery cell can be improved.

[0018] In some embodiments, the second redundant segment is connected to the first redundant segment. In the above technical solution, when the electrode assembly expands, the first wall portion is subjected to a certain pulling force in the front-to-back direction and the left-to-right direction. By setting the second redundant segment and the first redundant segment, the pulling force can be released to a certain extent at the second redundant segment and the first redundant segment. By pulling the second redundant segment and the first redundant segment to deform and unfold, the pulling force transmitted to the notched groove can be reduced, the probability of the notched groove being pulled and damaged can be reduced, the risk of leakage can be reduced, and the service life and reliability of the battery cell can be improved.

[0019] In some embodiments, the projection of the second redundant section on the first wall is arc-shaped, and the first redundant section is respectively provided on both sides of the notched groove in the first direction, and the two first redundant sections are connected by two second redundant sections through arc transition. In the above technical solution, the redundant part is runway-shaped, thereby, on the basis of buffering the notched groove in different directions, it can avoid too many sharp corners on the redundant part to a certain extent, which is conducive to the deformation and expansion of the redundant part, and avoids the redundant part having high local hardness and being difficult to deform and expand.

[0020] In some embodiments, the housing includes a pressure relief portion, the pressure relief portion has the notched groove, the pressure relief portion is integrally formed with the wall portion of the housing, and the wall portion of the housing is provided with the thinning area. In the above technical solution, by integrally forming the pressure relief portion with the first wall portion, the reliability of the pressure relief portion can be improved, the connection process between the pressure relief portion and the first wall portion is omitted, and the production and manufacturing cost of the battery cell can be reduced; the redundant portion can be integrally formed on the wall portion of the housing, and the manufacturing process is simple and the cost is low.

[0021] In some embodiments, the housing includes a pressure relief portion, the pressure relief portion has the notched groove, the pressure relief portion is separately arranged from the wall portion of the housing, the pressure relief portion is installed on the wall portion of the housing, the pressure relief portion is provided with the thinning area and / or the wall portion of the housing is provided with the thinning area. In the above technical solution, the pressure relief portion is a component independent of the wall portion of the housing, and the pressure relief portion and the wall portion of the housing can be produced and reassembled separately, with low production difficulty and high efficiency.

[0022] In some embodiments, the predetermined pressure relief zone has a predetermined opening boundary, and the predetermined opening boundary is surrounded by the outer edge of the orthographic projection of at least a portion of the scored groove in the depth direction of the scored groove; or the predetermined opening boundary is surrounded by the connecting line between multiple ends of the scored groove; or the predetermined opening boundary is jointly surrounded by the connecting line between multiple ends of the scored groove and the outer edge of the orthographic projection of at least a portion of the scored groove in the depth direction of the scored groove.

[0023] In a second aspect, the present application provides a battery, which includes the battery cell in the above embodiment.

[0024] In a third aspect, the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0025] 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

[0026] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0027] Figure 1 is a schematic diagram of an electrical device in the related art;

[0028] Figure 2 is a schematic diagram of a battery in the related art;

[0029] Figure 3 A schematic diagram of a battery provided for some embodiments of the present application;

[0030] Figure 4 An exploded view of a battery provided for some embodiments of the present application;

[0031] Figure 5 A cross-sectional view of a housing provided for some embodiments of the present application;

[0032] Figure 6 for Figure 5 The middle circle shows an enlarged view of A;

[0033] Figure 7 for Figure 6 The middle circle shows an enlarged view of B;

[0034] Figure 8 A partial schematic diagram of a first wall portion provided in some embodiments of the present application;

[0035] Fig. 9 A partial schematic diagram of a first wall portion provided for some other embodiments of the present application;

[0036] Fig.10 Schematic diagram of batteries provided for other embodiments of the present application;

[0037] Fig.11 A schematic diagram of an explosion-proof valve provided for some embodiments of the present application;

[0038] Fig.12 For along Fig.11 Sectional view of the mid-CC line;

[0039] Fig.13 A schematic diagram of a predetermined pressure relief area provided in some embodiments of the present application;

[0040] Fig.14 A schematic diagram of a predetermined pressure relief area provided in some other embodiments of the present application;

[0041] Fig.15Schematic diagram of a predetermined pressure relief zone provided in some further embodiments of the present application.

[0042] Reference numerals:

[0043] Battery 1000, power device 2000, housing 200, first part 210, first part 220,

[0044] Battery cell 100, housing 10, shell 101, end cover 102, first wall 11, second wall 12,

[0045] Electrode assembly 20, electrical connection portion 30, pressure relief portion 40, predetermined pressure relief area 401, notched groove 41, first arc segment 411, first straight segment 412, second straight segment 413, third straight segment 414, arc segment 415, fourth straight segment 416, fifth straight segment 417, sixth straight segment 418, seventh straight segment 419 (flip notch 419),

[0046] Redundant portion 50 , first redundant segment 51 , second redundant segment 52 , thinning area 60 , first direction F1 , second direction F2 , third direction F3 . DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0049] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0050] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0051] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0052] The term "plurality" used in the present application refers to two or more (including two).

[0053] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0054] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0055] The battery mentioned in the embodiments of the present application may include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in mixed connection through a busbar component.

[0056] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0057] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0058] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0059] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0060] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety performance of the battery must also be considered.

[0061] In a battery cell, to ensure the safety performance of the battery cell, a pressure relief portion may be provided on the outer shell of the battery cell. When the battery cell thermally runs away, the pressure inside the battery cell is released through the pressure relief portion to improve the safety of the battery cell.

[0062] During the charge and discharge process of the battery cell, the electrode assembly will expand, causing the outer shell to swell and deform. The pressure relief part is arranged on the outer shell, especially some pressure relief parts are arranged on the wall on the side closer to the electrode assembly. The expansion of the electrode assembly will deform the wall where the pressure relief part is located, thereby pulling the notch of the pressure relief part, causing the pressure relief part to be damaged at the notch and then leaking, etc. As a result, the pressure relief part will be damaged when the pressure inside the battery cell does not reach the detonation pressure of the pressure relief part, causing the pressure relief part to fail, and the reliability of the pressure relief part is low.

[0063] In view of this, an embodiment of the present application provides a battery cell, comprising: an electrode assembly; a shell for accommodating the electrode assembly, the shell being provided with a notched groove, the notched groove defining a predetermined pressure relief zone that opens when the battery cell is depressurized, wherein the shell is provided with a redundant portion that arches toward a side close to and / or away from the electrode assembly, and the redundant portion is located outside the predetermined pressure relief zone.

[0064] In such a battery cell, by arranging a redundant portion on the outside of the notched groove, when the electrode assembly expands, the expansion force of the electrode assembly can pull the redundant portion, causing the redundant portion to deform to a certain extent. The redundant portion absorbs at least part of the expansion force of the electrode assembly, thereby reducing the expansion force acting on the notched groove, reducing the pulling force on the notched groove, and reducing the probability of the notched groove being pulled and damaged, resulting in leakage, thereby improving the service life and reliability of the battery cell.

[0065] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0066] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0067] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0068] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 2000 provided in some embodiments of the present application. A battery 1000 is disposed inside the vehicle 2000, and the battery 1000 may be disposed at the bottom, head, or tail of the vehicle 2000. The battery 1000 may be used to power the vehicle 2000, for example, the battery 1000 may be used as an operating power source for the vehicle 2000.

[0069] The vehicle 2000 may further include a controller and a motor, wherein the controller is used to control the battery 1000 to supply power to the motor, for example, to meet the power requirements of the vehicle 2000 during starting, navigation, and driving.

[0070] In some embodiments of the present application, the battery 1000 can not only serve as an operating power source for the vehicle 2000, but also serve as a driving power source for the vehicle 2000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 2000.

[0071] Please refer to Figure 2 , Figure 2 The exploded view of the battery 1000 provided in some embodiments of the present application. The battery 1000 includes a battery cell 100 and a box 200 , and the box 200 is used to accommodate the battery cell 100 .

[0072] Among them, the box body 200 is a component for accommodating the battery cell 100. The box body 200 provides a placement space for the battery cell 100. The box body 200 can adopt a variety of structures. In some embodiments, the box body 200 may include a first part 210 and a second part 220, and the first part 210 and the second part 220 cover each other to define a placement space for accommodating the battery cell 100. The first part 210 and the second part 220 may be in a variety of shapes, such as a cuboid, a cylinder, etc. The first part 210 may be a hollow structure with one side open, and the second part 220 may also be a hollow structure with one side open, and the open side of the second part 220 covers the open side of the first part 210, so as to form a box body 200 with a placement space. It is also possible that the first part 210 is a hollow structure with one side open, and the second part 220 is a plate-like structure, and the second part 220 covers the open side of the first part 210, so as to form a box body 200 with a placement space. As an example, the battery cell 100 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell 100 of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal prismatic battery, such as a hexagonal prismatic battery, etc. There is no special limitation in the present application.

[0073] In the battery 1000, there can be one or more battery cells 100. If there are more than one battery cell 100, the multiple battery cells 100 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 100 are both connected in series and in parallel. Multiple battery cells 100 can be connected in series, in parallel, or in mixed connection to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 200. Alternatively, all battery cells 100 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by all battery cells 100 is accommodated in the box 200.

[0074] Please refer to Figure 3 and Figure 4 , Figure 3 A schematic diagram of a battery provided for some embodiments of the present application, Figure 4 An exploded view of a battery provided in some embodiments of the present application. A battery cell 10 may include a housing 10 and an electrode assembly 20 .

[0075] The housing 10 is used to accommodate the electrode assembly 20 and electrolyte and other components. The housing 10 may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film, etc. As an example, the housing 10 may include a shell 101 and an end cap 102.

[0076] The housing 101 may be a hollow structure with an opening at one end, or may be a hollow structure with openings at two opposite ends. The housing 101 may be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, and the like.

[0077] The end cap 102 is a component that closes the opening of the shell 101 to isolate the internal environment of the battery cell 100 from the external environment. The end cap 102 and the shell 101 together define a storage space for accommodating the electrode assembly 20, the electrolyte and other components. The end cap 102 can be connected to the shell 101 by welding or crimping to close the opening of the shell 101. The shape of the end cap 102 can be compatible with the shape of the shell 10. For example, the shell 101 is a rectangular parallelepiped structure, and the end cap 102 is a rectangular plate structure that is compatible with the shell 10. The material of the end cap 102 can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0078] In the battery cell 10, there may be one or two end caps 102. In the embodiment where the shell 101 is a hollow structure with openings formed at both ends, two end caps 102 may be provided accordingly, and the two end caps 102 respectively close the two openings of the shell 101, and the two end caps 102 and the shell 101 jointly define a storage space. In the embodiment where the shell 101 is a hollow structure with an opening formed at one end, there may be one end cap 102 provided accordingly, and the end cap 102 closes the opening at one end of the shell 101, and the one end cap 102 and the shell 101 jointly define a storage space.

[0079] The electrode assembly 20 includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell 100, active ions (such as lithium ions) are inserted and removed between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0080] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode collector and a positive electrode active material region disposed on at least one surface of the positive electrode collector, wherein the positive electrode active material region has a positive electrode active material.

[0081] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material region is disposed on any one or both of the two facing surfaces of the positive electrode current collector.

[0082] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector and a negative electrode active material region disposed on at least one surface of the negative electrode current collector.

[0083] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material region is disposed on any one or both of the two facing surfaces of the negative electrode current collector.

[0084] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0085] In some embodiments, the electrode assembly 20 further includes a separator disposed between the positive electrode and the negative electrode.

[0086] In some embodiments, 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.

[0087] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0088] In some embodiments, the battery cell 100 further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0089] In some embodiments, the electrode assembly 20 is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0090] In some embodiments, the electrode assembly 20 is a laminate structure.

[0091] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0092] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet is folded to form a plurality of stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0093] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded sections. As an example, a plurality of separators may be provided, respectively provided between any adjacent positive electrode sheets or negative electrode sheets. As an example, the separators may be provided continuously, and provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0094] In some embodiments, the shape of the electrode assembly 20 can be flat or polygonal.

[0095] In some embodiments, the electrode assembly 20 is provided with tabs, which can conduct current from the electrode assembly 20. The tabs include a positive tab and a negative tab.

[0096] The battery cell 100 may further include an electrical connection portion, which may be disposed on the housing 10 and is used to electrically connect to the tab of the electrode assembly 20 to output the electrical energy of the battery cell 10. The electrical connection portion and the tab may be directly connected, for example, the electrical connection portion and the tab are directly welded. The electrical connection portion and the tab may also be indirectly connected, for example, the electrical connection portion and the tab are indirectly connected through a current collecting member. The current collecting member may be a metal conductor, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0097] like Figure 3 and Figure 4 As shown, taking the shell 101 as an example of a hollow structure with an opening at one end, two electrical connection parts can be set on the end cover 102, and the two electrical connection parts are respectively a positive electrical connection part and a negative electrical connection part, the positive electrical connection part is electrically connected to the positive electrode ear, and the negative electrical connection part is electrically connected to the negative electrode ear.

[0098] Please refer to Figure 5-Figure 11 According to an embodiment of the present application, a battery cell 100 includes: an electrode assembly 20 and a shell 10, the shell 10 is used to accommodate the electrode assembly 20, the shell 10 is provided with a notch groove 41, the notch groove 41 defines a predetermined pressure relief area 401 that is opened when the battery cell 100 is depressurized, wherein the shell 10 is provided with a redundant portion 50 that is arched toward a side close to and / or away from the electrode assembly 20, and the redundant portion 50 is located outside the predetermined pressure relief area 401.

[0099] The housing 10 refers to the outermost structural member of the battery cell 100 , and the housing 10 accommodates the electrode assembly 20 and electrolyte, etc.

[0100] The electrode assembly 20 is disposed in the housing 10. There may be one electrode assembly 20 or multiple electrode assemblies 20 in the housing 10. Each electrode assembly 20 includes at least one positive electrode sheet and at least one negative electrode sheet.

[0101] The shell 10 is provided with a notched groove 41, which can be arranged on the wall of the shell 10, and can also be arranged on a structural member installed on the wall of the shell 10. The notched groove 41 defines a predetermined pressure relief area 401. The predetermined pressure relief area 401 is used to release the internal pressure of the battery cell 100 when the internal pressure of the battery cell 100 reaches a threshold value, that is, the discharge medium inside the battery cell 100 can be discharged through the predetermined pressure relief area 401 to achieve the purpose of pressure relief. The threshold design varies according to different design requirements, and the threshold may depend on one or more materials of the positive electrode plate, the negative electrode plate, the electrolyte and the separator in the battery cell 100.

[0102] Among them, the predetermined pressure relief area 401 has a predetermined opening boundary, and the predetermined opening boundary is surrounded by the outer edge of the positive projection of at least a part of the notched groove 41 in the second direction F2; or the predetermined opening boundary is surrounded by the connecting line between multiple ends of the notched groove 41; or the predetermined opening boundary is jointly surrounded by the connecting line between multiple ends of the notched groove 41 and the outer edge of the positive projection of at least a part of the notched groove 41 in the second direction F2.

[0103] The shell 10 is provided with a redundant portion 50 which is arched toward a side close to and / or away from the electrode assembly 20. The redundant portion 50 is located outside the predetermined pressure relief area 401. By arranging the redundant portion 50 on the shell 10, the shell 10 is partially provided with a buffer structure. The redundant portion 50 can store a certain deformation space. When the electrode assembly 20 expands, the expansion force of the electrode assembly 20 can preferentially pull the redundant portion 50, causing the redundant portion 50 to deform to a certain extent, releasing the stored deformation space, and unfolding the redundant portion 50 to a certain extent. As a result, the redundant portion 50 absorbs at least part of the expansion force of the electrode assembly 20, thereby reducing the expansion force acting on the notched groove 41, reducing the pulling force on the notched groove 41, and thereby reducing the probability of the notched groove 41 being pulled and damaged, resulting in leakage.

[0104] Among them, the redundant part 50 can be arched toward the side close to the electrode assembly 20, the redundant part 50 can also be arched toward the side away from the electrode assembly 20, the redundant part 50 can also be a part arched toward the side close to the electrode assembly 20, and the other part arched toward the side away from the electrode assembly 20, and a part of the redundant part 50 is located on the side of the other part close to or away from the geometric center of the predetermined pressure relief zone 401.

[0105] In the technical solution of the embodiment of the present application, a redundant portion 50 is provided on the outer side of the notched groove 41. When the electrode assembly 20 expands, the expansion force of the electrode assembly 20 can pull the redundant portion 50, causing the redundant portion 50 to undergo a certain deformation. As a result, the redundant portion 50 absorbs at least part of the expansion force of the electrode assembly 20, thereby reducing the expansion force acting on the notched groove 41, thereby reducing the pulling force on the notched groove 41. The redundant portion 50 acts as a buffer, thereby reducing the probability of the notched groove 41 being pulled and damaged, resulting in leakage, thereby improving the service life and reliability of the battery cell 100.

[0106] Reference Figure 5-Figure 8 As shown, Figure 5 A cross-sectional view of a housing provided for some embodiments of the present application; Figure 6 for Figure 5 The middle circle shows an enlarged view of A; Figure 7 for Figure 6 The middle circle shows an enlarged view of B; Figure 8A partial schematic diagram of the first wall portion provided for some embodiments of the present application; in some embodiments, the outer shell 10 is provided with a thinning area 60, the minimum thickness of the thinning area 60 is greater than the maximum thickness at the notch groove 41 and the maximum thickness of the thinning area 60 is less than the thickness of the wall portion of the outer shell 10 where the thinning area 60 is located, and a portion of the thinning area 60 is arched toward and / or away from the side of the electrode assembly 20 to form a redundant portion 50.

[0107] A portion of the shell 10 is thinned to form a thinning area 60, wherein the shell 10 includes a wall portion and a pressure relief portion 40, and the thinning area 60 can be formed by thinning a portion of the wall portion or a portion of the pressure relief portion 40.

[0108] like Figure 6 As shown, the first wall portion 11 of the housing 10 is provided with a thinning area 60, and the thinning area 60 may be a structure of equal thickness, the thickness of which is less than the maximum thickness of the first wall portion 11 and greater than the maximum thickness at the notch groove 41; the thinning area 60 may also be a structure of variable thickness, the maximum thickness of the thinning area 60 is less than the maximum thickness of the first wall portion 11, and the minimum thickness of the thinning area 60 is greater than the maximum thickness at the notch groove 41. The shape of the thinning area 60 projected on the plane where the first wall portion 11 is located may be a square with rounded corners, or a circle, or an oblong, or an ellipse, and the thinning area 60 may also be formed in a ring shape, and the edge of the thinning area 60 is arc-shaped, thereby avoiding stress concentration at the edge of the thinning area 60, which may cause the edge of the thinning area 60 to be damaged and cause leakage, etc.

[0109] A portion of the thinning area 60 is arched toward the side close to the electrode assembly 20 to form a redundant portion 50, and / or a portion of the thinning area 60 is arched toward the side away from the electrode assembly 20 to form a redundant portion 50. The redundant portion 50 can be a structure of equal thickness or a structure of variable thickness. The maximum thickness of the redundant portion 50 is less than the maximum thickness of the first wall portion 11, and the minimum thickness of the redundant portion 50 is greater than the maximum thickness at the notch groove 41.

[0110] By setting the thinning area 60, the thinning area 60 is more likely to deform, and the redundant part 50 is set in the thinning area 60, so that the redundant part 50 is deformed under the action of the expansion force of the electrode assembly 20 and is pulled and unfolded. Since the thickness of the thinning area 60 is greater than the maximum thickness at the notched groove 41, the probability of the redundant part 50 being damaged and leaking due to the redundant part 50 being pulled due to the thickness being too small can be avoided. At the same time, it is ensured to a certain extent that the notched groove 41 is the weakest position of the entire battery cell 100, so that when the internal pressure of the battery cell 100 reaches a threshold, the internal pressure of the battery cell 100 is released at a predetermined position to achieve the purpose of pressure relief at a specific position.

[0111] like Figure 6As shown, in some embodiments, the score groove 41 is disposed in the thinned region 60 .

[0112] like Figure 6 As shown, the middle portion of the thinning zone 60 has a notch groove 41, and the redundant portion 50 is located on one side of the notch groove 41 close to the edge of the thinning zone 60, so that the notch groove 41 and the redundant portion 50 can be directly manufactured on the thinning zone 60. For example, the redundant portion 50 can be formed by a stamping process, and the notch groove 41 can be formed by an etching process, so that the thickness of the thinning zone 60 at the notch groove 41 is less than the thickness of the redundant portion 50.

[0113] In this way, when the electrode assembly 20 expands, the expansion force of the electrode assembly 20 can preferentially pull the redundant part 50, causing the redundant part 50 to undergo a certain deformation, thereby absorbing at least part of the expansion force of the electrode assembly 20 and reducing the expansion force acting on the notched groove 41. At the same time, the probability of the redundant part 50 being damaged and leaking due to the redundant part 50 being pulled due to the thickness being too small can be avoided. The notched groove 41 can also be made the weakest position of the entire battery cell 100, so that when the internal pressure of the battery cell 100 reaches a threshold, the internal pressure of the battery cell 100 can be released at a predetermined position, thereby achieving the purpose of pressure relief at a specific position.

[0114] like Figure 3-Figure 7 As shown, in some embodiments, the maximum height dimension of the redundant portion 50 along the direction approaching and / or away from the electrode assembly 20 is H, and the maximum width dimension of the redundant portion 50 along the direction away from the notch groove 41 is W, and 0.03≤H / W≤10.

[0115] like Figure 7 As shown, in the first direction F1, the maximum width dimension of the redundant portion 50 is W, and in the second direction F2, the maximum height dimension of the redundant portion 50 is H. Figure 7 As shown, the redundant portion 50 is a structural member of equal thickness. In the up-down direction, the upper surface and the lower surface of the redundant portion 50 are both arched downward. In the up-down direction, the maximum height distance between the highest point and the lowest point of the upper surface is the same as the maximum height distance between the highest point and the lowest point of the lower surface. This maximum height distance is the maximum height H of the redundant portion 50. Of course, if the redundant portion 50 is a structure of non-equal thickness, the larger value of the maximum height distance between the highest point and the lowest point of the upper surface and the maximum height distance between the highest point and the lowest point of the lower surface is the maximum height H of the redundant portion 50.

[0116] Among them, if H / W is too large, the redundant part 50 is arched to a large height and a small width, which is not convenient for the manufacturing and molding of the redundant part 50. If H / W is too small, the redundant part 50 is arched to a small height and a large width, the redundant part 50 has little deformable space, and the redundant part 50 has limited ability to absorb the expansion force of the electrode assembly 20, which makes the notched groove 41 easy to be pulled and damaged when the electrode assembly 20 expands.

[0117] To this end, H / W can be limited to between 0.03-10, and H / W can be any point value among 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, or a range value between any two of them.

[0118] Therefore, it is convenient to manufacture and form the redundant part 50 , and when the electrode assembly 20 expands, the redundant part 50 can undergo a certain deformation, thereby absorbing at least part of the expansion force of the electrode assembly 20 , reducing the expansion force acting on the notched groove 41 , and reducing the probability of the notched groove 41 being pulled and damaged, resulting in leakage, thereby improving the service life and reliability of the battery cell 100 .

[0119] like Figure 7 As shown, in some embodiments, along the direction approaching and / or away from the electrode assembly 20 , the maximum height dimension of the redundant portion 50 is H, and 0.1 mm≤H≤2 mm.

[0120] like Figure 7 As shown, in the second direction F2, the maximum height of the redundant part 50 is H. If H is too large, on the one hand, the redundant part 50 protrudes from the wall of the housing 10, so that the redundant part 50 will occupy the space inside the battery cell 100 in the second direction F2, thereby affecting the space of the electrode assembly 20, or protrude from the wall of the housing 10 and affect the placement of the battery cell 100, resulting in a reduction in the energy density of the battery cell 100. On the other hand, in the manufacturing process, stamping the redundant part 50 requires pulling the parts around the redundant part 50, and the increase in the height of the redundant part 50 causes more pulling around the redundant part 50. For the redundant part 50 and the notched groove 41 located on the same structural part, it is easy to cause the notched part to become thinner and harder, and then it is easier to be damaged during the use of the battery cell 100, resulting in leakage. If H is too small, the redundant part 50 has less deformable space, and the redundant part 50 has limited ability to absorb the expansion force of the electrode assembly 20, thereby making the notched groove 41 easy to be pulled and damaged when the electrode assembly 20 expands.

[0121] To this end, H can be limited to between 0.1mm and 2mm, and H can be any point value among 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or a range value between any two of them.

[0122] As a result, the redundant part 50 can be manufactured and formed easily without causing a significant impact on other structural parts. At the same time, the redundant part 50 can undergo a certain deformation when the electrode assembly 20 expands, absorbing at least part of the expansion force of the electrode assembly 20, thereby reducing the expansion force acting on the notched groove 41, reducing the probability of the notched groove 41 being pulled and damaged, resulting in leakage, and improving the service life and reliability of the battery cell 100.

[0123] like Figure 7 As shown, in some embodiments, along the direction away from the score groove 41 , the maximum width dimension of the redundant portion 50 is W, and 0.2 mm≤W≤3 mm.

[0124] like Figure 7 As shown, in the first direction F1, the maximum width dimension of the redundant part 50 is W. If W is too large, the width of the redundant part 50 in the first direction F1 is large, and the redundant part 50 occupies more space, resulting in the area of ​​the predetermined pressure relief zone 401 being too small, which may be difficult to meet the demand for timely discharge of the gas inside the battery cell 100, posing a safety hazard; if W is too small, it is not conducive to the manufacturing and forming of the redundant part 50.

[0125] To this end, W can be limited to between 0.2mm and 3mm, and H can be any point value among 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, and 3mm, or a range value between any two of them.

[0126] Therefore, the redundant part 50 can be manufactured and formed easily without causing a significant impact on other structural parts, thereby increasing the area of ​​the predetermined pressure relief zone 401 , meeting the exhaust demand, improving the timeliness of the explosion of the pressure relief part 40 , and improving the reliability of the battery cell 100 .

[0127] like Figure 5-Figure 7As shown, in some embodiments, the redundant portion 50 extends along the outer periphery of the predetermined pressure relief area 401 , and the shape of the cross section of the redundant portion 50 perpendicular to the extending direction of the redundant portion 50 is an arc.

[0128] like Figure 7 As shown, the cross-section of the redundant part 50 is arc-shaped. The arc-shaped design is convenient for the manufacturing and forming of the redundant part 50. At the same time, the redundant part 50 with an arc-shaped design is easier to be unfolded when the electrode assembly 20 expands, thereby avoiding the redundant part 50 from being difficult to unfold and deformed due to the high local bending hardness. The redundant part 50 can undergo a certain deformation when the electrode assembly 20 expands, absorb at least part of the expansion force of the electrode assembly 20, and alleviate the problem of the score groove 41 being pulled and damaged by the expansion force of the electrode assembly 20, resulting in leakage.

[0129] In addition, both ends of the redundant portion 50 are connected to the wall of the housing 10 by a circular arc transition, thereby further avoiding sharp corners and preventing the redundant portion 50 from being difficult to deform and unfold due to high hardness at the corners.

[0130] like Figure 6 , Figure 8 and Fig. 9 As shown, in some embodiments, the redundant portions 50 are symmetrically arranged along the geometric center of the housing 10 .

[0131] The housing 10 has a central plane in the front-to-back direction, and the redundant parts 50 are symmetrically arranged along the central plane. The housing 10 has a central plane in the left-to-right direction, and the redundant parts 50 are symmetrically arranged along the central plane. Figure 8 and Fig. 9 As shown, the redundant part 50 is arranged on the first wall part 11, and the two first redundant sections 51 of the redundant part 50 are symmetrically arranged on the front and rear sides of the notched groove 41, and the two second redundant sections 52 of the redundant part 50 are symmetrically arranged on the left and right sides of the notched groove 41. The redundant part 50 is symmetrically arranged relative to the center of the predetermined pressure relief area 401.

[0132] Thus, the shell 10 as a whole forms a symmetrical structure, which, on the one hand, facilitates the manufacture of the redundant part 50, and on the other hand, enables the redundant part 50 to play the same buffering role on the notched groove 41 at each position, thereby reducing the probability of the notched groove 41 being partially pulled and broken, thereby improving the reliability of the entire battery cell 100.

[0133] like Figure 3-Figure 12As shown, in some embodiments, the electrode assembly 20 includes at least one positive electrode sheet and at least one negative electrode sheet, and the at least one positive electrode sheet and the at least one negative electrode sheet are stacked to form a straight area, and at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked in the straight area along a first direction F1, and the outer shell 10 includes a first wall portion 11, and the first wall portion 11 is located on one side of the electrode assembly 20 in a second direction F2, and the second direction F2 is the thickness direction of the first wall portion 11 and is perpendicular to the first direction F1, and the first wall portion 11 is provided with a notch groove 41 and a redundant portion 50.

[0134] The electrode assembly 20 may be a stacked type, that is, a plurality of electrode sheets of the electrode assembly 20 are stacked, and the electrode sheets are stacked to form a straight area. In the straight area, at least a portion of the positive electrode sheet and the negative electrode sheet are stacked along the first direction F1, or at least a portion of the positive electrode sheet and the negative electrode sheet are stacked along the first direction F1. As a result, the expansion deformation of the electrode assembly 20 is particularly obvious in the first direction F1.

[0135] The electrode assembly 20 may also be of a wound type, in which the positive electrode sheet and the negative electrode sheet of the electrode assembly 20 are superimposed on the isolation member and then wound to form a straight area. In the straight area, part of the positive electrode sheet and part of the negative electrode sheet are stacked along the first direction F1. For example, after winding, each layer of the positive electrode sheet and each layer of the negative electrode sheet can be penetrated by an axis extending along the first direction F1, so that the expansion deformation of the electrode assembly 20 is particularly obvious in the first direction F1.

[0136] like Figure 4 As shown, the first direction F1 is the front-to-back direction, and the second direction F2 is the up-down direction.

[0137] The shell 10 includes a first wall portion 11, which is located on one side of the electrode assembly 20 in a second direction F2, the second direction F2 is perpendicular to the first direction F1, the thickness direction of the first wall portion 11 is the second direction F2, and the first wall portion 11 is provided with a notch groove 41 and a redundant portion 50.

[0138] Among them, Figure 3-Figure 7 As shown, the notch groove 41 can be integrally formed on the first wall portion 11, or as shown in Figure 10-12 As shown, the notch groove 41 may be formed on the pressure relief portion 40 , and the pressure relief portion 40 is mounted on the first wall portion 11 .

[0139] The redundant portion 50 is located between the notched groove 41 and the outer edge of the first wall portion 11. When the electrode assembly 20 expands, the expansion force acts on the outer shell 10 to stretch the first wall portion 11. By providing the redundant portion 50, the first wall portion 11 can have more stretching at the redundant portion 50. The redundant portion 50 undergoes a certain deformation to absorb at least part of the expansion force of the electrode assembly 20, thereby reducing the expansion force acting on the notched groove 41, thereby reducing the stretching at the notched groove, reducing the probability of the notched groove being pulled and damaged, resulting in leakage, and improving the service life and reliability of the battery cell 100.

[0140] like Figure 4 and Fig.10 As shown, in some embodiments, the first wall portion 11 is used to support the electrode assembly 20 and is located below the electrode assembly 20, so that the notch groove 41 can be provided at the bottom of the battery cell 100, and the bottom of the battery cell 100 can be provided with an exhaust channel, and the exhaust channel can be connected to the predetermined pressure relief area 401, so that when the battery cell 100 has thermal runaway, the high-temperature and high-pressure flue gas can be discharged into the exhaust channel through the predetermined pressure relief area 401 at the bottom, and then discharged to the outside.

[0141] like Fig. 9 As shown, in some embodiments, the redundant portion 50 includes a first redundant segment 51 , and the first redundant segment 51 is located at one side of the notch groove 41 in the first direction F1 .

[0142] like Fig. 9 As shown, in some examples, in the first direction F1, a first redundant segment 51 is provided on one side of the notch groove 41. Of course, in other examples, a plurality of first redundant segments 51 are provided on one side of the notch groove 41. The plurality of first redundant segments 51 may be arranged at intervals along the first direction F1. The plurality of first redundant segments 51 may be arched in a direction close to the electrode assembly 20 or in a direction away from the electrode assembly 20.

[0143] like Figure 4 As shown, the shell 10 also includes two second wall portions 12, and the two second wall portions 12 are respectively located on both sides of the electrode assembly 20 in the first direction F1. Most of the expansion of the electrode assembly 20 will act on the second wall portions 12. When the electrode assembly 20 expands, the second wall portion 12 is pulled and deformed, and the second wall portion 12 pulls the first wall portion 11, so that the first wall portion 11 is subjected to a larger pulling force in the front-to-back direction, that is, the influence of the electrode assembly 20 on the first wall portion 11 in the front-to-back direction is less than the influence of the electrode assembly 20 on the first wall portion 11 in the left-to-right direction.

[0144] like Fig. 9As shown, the first redundant segment 51 is located at the front and rear sides of the notched groove 41. When the electrode assembly 20 expands, the first wall portion 11 is subjected to a large pulling force in the front and rear directions and can be released to a certain extent at the first redundant segment 51. By pulling the first redundant segment 51 to deform, the pulling force transmitted to the notched groove 41 can be reduced, the probability of the notched groove 41 being pulled and damaged can be reduced, the risk of leakage can be reduced, and the service life and reliability of the battery cell 100 can be improved.

[0145] like Fig. 9 As shown, in some embodiments, the maximum length of the predetermined pressure relief area 401 in the third direction F3 is L1, and the maximum slot length of the first redundant segment 51 in the third direction F3 is L2, satisfying: L2 / L1≥0.9, and the third direction F3 is perpendicular to the first direction F1 and the second direction F2 respectively.

[0146] like Fig. 9 As shown, the third direction F3 is the left and right direction as shown in the figure. In the left and right direction, if the groove length of the first redundant segment 51 is too small, so that in the first direction F1, there is no first redundant segment 51 between part of the notched groove 41 and the outer edge of the first wall portion 11, it is easy to cause the local notched groove 41 to be pulled and damaged. For this reason, L2 / L1 is limited to greater than or equal to 0.9, and L2 / L1 can be 0.9, 1, 1.1, 1.15, 1.2, 1.25, etc.

[0147] As a result, the pulling force on various positions of the entire predetermined pressure relief area 401 is reduced to a certain extent. By pulling the first redundant section 51 to deform and expand, a buffering effect can be played on the various parts where the notched groove is located, reducing the probability of the notched groove being pulled and damaged, resulting in leakage, and improving the service life and reliability of the battery cell 100.

[0148] like Fig. 9 As shown, in some embodiments, the redundant portion 50 includes a second redundant segment 52, and the second redundant segment 52 is located on one side of the notch groove 41 in the third direction F3, and the third direction F3 is perpendicular to the first direction F1 and the second direction F2.

[0149] like Fig. 9 As shown, a second redundant segment 52 is respectively provided on the left and right sides of the notch groove 41. The second redundant segment 52 can extend in an arc direction or in the front-to-back direction. When the electrode assembly 20 expands, the first wall portion 11 is subjected to a certain pulling force in the left and right directions. By providing the second redundant segment 52, the pulling force can be released to a certain extent at the second redundant segment 52. By pulling the second redundant segment 52 to deform and expand, the pulling force transmitted to the notch groove 41 can be reduced, the probability of the notch groove 41 being pulled and damaged can be reduced, the risk of leakage can be reduced, and the service life and reliability of the battery cell 100 can be improved.

[0150] like Figure 8 As shown, in some embodiments, the second redundant segment 52 is connected to the first redundant segment 51 .

[0151] like Figure 8 As shown, a first redundant segment 51 is respectively provided on the front and rear sides of the notched groove 41, and the front and rear ends of the second redundant segment 52 are respectively connected to the first redundant segment 51, so that the redundant portion 50 forms a ring, that is, the ring-shaped redundant portion 50 is arranged on the outer circle of the notched groove 41 as a whole; of course, the front and rear ends of the second redundant segment 52 may also have a certain interval with the first redundant segment 51.

[0152] When the electrode assembly 20 expands, the first wall portion 11 is subjected to a certain pulling force in the front-to-back direction and the left-to-right direction. By providing the second redundant segment 52 and the first redundant segment 51, the pulling force can be released to a certain extent at the second redundant segment 52 and the first redundant segment 51. By pulling the second redundant segment 52 and the first redundant segment 51 to deform and expand, the pulling force transmitted to the notched groove 41 can be reduced, thereby reducing the probability of the notched groove 41 being pulled and damaged, reducing the risk of leakage, and improving the service life and reliability of the battery cell 100.

[0153] like Figure 8 As shown, in some embodiments, the projection of the second redundant segment 52 on the first wall portion 11 is arc-shaped, and a first redundant segment 51 is respectively provided on both sides of the notched groove 41 in the first direction F1, and the two first redundant segments 51 are connected by two second redundant segments 52 through an arc transition.

[0154] like Figure 8 As shown, the redundant portion 50 is in a runway shape, thereby, on the basis of buffering the notched groove 41 in different directions, it can avoid having too many sharp corners on the redundant portion 50 to a certain extent, which is beneficial to the deformation and expansion of the redundant portion 50, and avoids the redundant portion 50 having high local hardness and being difficult to deform and expand.

[0155] like Figure 3 and Figure 4 As shown, in some embodiments, the housing 10 includes a pressure relief portion 40 having a notched groove 41 , the pressure relief portion 40 is integrally formed with the wall of the housing 10 , and the wall of the housing 10 is provided with a thinned area 60 .

[0156] The shell 10 includes a wall portion and a pressure relief portion 40, wherein the pressure relief portion 40 is integrally formed with the wall portion of the shell 10, the portion with the notched groove 41 serves as the pressure relief portion 40, a portion of the wall portion of the shell 10 is thinned to form a thinning area 60, and a portion of the thinning area 60 is arched to form a redundant portion 50.

[0157] By integrally forming the pressure relief portion 40 with the first wall portion 11, the reliability of the pressure relief portion 40 can be improved, the connection process between the pressure relief portion 40 and the first wall portion 11 is eliminated, and the production cost of the battery cell 100 can be reduced; the redundant portion 50 can be integrally formed on the wall portion of the outer shell 10, and the manufacturing process is simple and the cost is low.

[0158] like Fig.10 As shown, in some embodiments, the housing 10 includes a pressure relief portion 40, the pressure relief portion 40 has a notched groove 41, the pressure relief portion 40 is separately arranged from the wall portion of the housing 10, the pressure relief portion 40 is installed on the wall portion of the housing 10, the pressure relief portion 40 is provided with a thinning area 60 and / or the wall portion of the housing 10 is provided with a thinning area 60.

[0159] like Fig.10 As shown, the pressure relief portion 40 and the wall of the shell 10 are two separate components, which are separately molded and then installed together. Specifically, the pressure relief portion 40 can be a component such as an explosion-proof plate, an explosion-proof valve, or a safety valve. The pressure relief portion 40 can be installed on the wall of the shell 10 by bonding, welding, etc. The wall of the shell 10 is provided with a through hole, and the pressure relief portion 40 is installed in the through hole. When the internal pressure of the battery cell 100 reaches a threshold value, the pressure relief portion 40 opens at least part of the through hole, and the discharge medium inside the battery cell 100 is discharged through the through hole to release the pressure inside the battery cell 100.

[0160] Taking the case where the pressure relief portion 40 is an explosion-proof disc and is installed on the first wall portion 11 as an example, the explosion-proof disc is a sheet body whose strength in at least a part of the area is less than that of the first wall portion 11, the explosion-proof disc covers the through hole, and the explosion-proof disc is welded to the first wall portion 11. When the internal pressure of the battery cell 100 reaches a threshold value, the explosion-proof disc is at least partially destroyed, thereby opening at least a part of the through hole to release the pressure inside the battery cell 100.

[0161] In this embodiment, the pressure relief portion 40 is a component independent of the wall portion of the housing 10 . The pressure relief portion 40 and the wall portion of the housing 10 can be produced and reassembled separately, which has low production difficulty and high efficiency.

[0162] In some examples, the pressure relief portion 40 is a separate structural member, the pressure relief portion 40 is provided with a notched groove 41, the pressure relief portion 40 is fixedly connected to the first wall portion 11, for example, by welding, the redundant portion 50 is arranged on a portion of the first wall portion 11 to be thinned to form a thinning area 60, a portion of the thinning area 60 is arched to form the redundant portion 50, when the electrode assembly 20 expands, the expansion force of the electrode assembly 20 pulls the first wall portion 11, and the connection between the pressure relief portion 40 and the first wall portion 11 is pulled, causing the connection to be easily damaged, by 1, so that the first wall portion 11 can have more stretching at the redundant portion 50, thereby reducing the stretching of the connection between the pressure relief portion 40 and the first wall portion 11. The redundant portion 50 can play an effective buffering role at the connection between the pressure relief portion 40 and the first wall portion 11, reducing the probability of the connection being pulled and damaged, resulting in leakage, and at the same time reducing the stretching at the notched groove 41, reducing the probability of the housing 10 being pulled and damaged at the notched groove 41, resulting in leakage, thereby improving the service life and reliability of the battery cell 100.

[0163] like Fig.12 As shown, in some examples, the pressure relief portion 40 is a separate structural member, a portion of the pressure relief portion 40 is thinned to form a thinning area 60, and a portion of the thinning area 60 is arched to form a redundant portion 50. By forming the redundant portion 50 on the pressure relief portion 40, the manufacturing of the redundant portion 50 is facilitated, and the pressure relief portion 40 and the wall of the outer shell 10 can be produced and reassembled separately, with low production difficulty and high efficiency.

[0164] like Figure 13-Figure 15 As shown, in some embodiments, the predetermined pressure relief zone 401 has a predetermined opening boundary, and the predetermined opening boundary is surrounded by the outer edge of the positive projection of at least a portion of the notched groove 41 in the depth direction of the notched groove 41; or the predetermined opening boundary is surrounded by the connecting line between multiple ends of the notched groove 41; or the predetermined opening boundary is jointly surrounded by the connecting line between multiple ends of the notched groove 41 and the outer edge of the positive projection of at least a portion of the notched groove 41 in the depth direction of the notched groove 41.

[0165] In some embodiments, the predetermined pressure relief zone 401 has a predetermined opening boundary, and the predetermined opening boundary is surrounded by the outer edge of the positive projection of at least a portion of the notched groove 41 in the second direction F2; or the predetermined opening boundary is surrounded by the connecting line between multiple ends of the notched groove 41; or the predetermined opening boundary is jointly surrounded by the connecting line between multiple ends of the notched groove 41 and the outer edge of the positive projection of at least a portion of the notched groove 41 in the second direction F2.

[0166] like Fig.13As shown, in some embodiments, the notched groove 41 includes two first arc segments 411 arranged opposite to each other and two first straight line segments 412 arranged in parallel, and both ends of each first straight line segment 412 are respectively connected to the two first arc segments 411, and the two first straight line segments 412 and the two first arc segments 411 form a closed annular structure; in the second direction F2, the outer edge of the positive projection of the annular structure constitutes a predetermined opening boundary of the predetermined pressure relief area 401, that is, the predetermined opening boundary is surrounded by the outer edge of the positive projection of the notched groove 40 in the second direction F2.

[0167] At this time, the maximum length of the predetermined pressure relief area 401 along the third direction F3 is L1, L1=a+b, wherein a represents the length of the first straight line segment 412 , and b represents the distance between the outer sides of two first straight line segments 412 .

[0168] like Fig.14 As shown, in some embodiments, the notched groove 41 includes a second straight line segment 413 and four third straight line segments 414, and the two ends of the second straight line segment 413 are respectively connected to two third straight line segments 414 set at a preset angle; in the second direction F2, an arc segment 415 with the vertex of the preset angle as the center is defined between the free ends of the positive projections of the two third straight line segments 414 located at the same end of the second straight line segment 413, and a fourth straight line segment 416 is defined between the free ends of the positive projections of the two third straight line segments 414 located on the same side of the second straight line segment 413, and the two arc segments 415 and the two fourth straight line segments 416 together constitute a predetermined opening boundary of the predetermined pressure relief area 401, that is, the predetermined opening boundary is surrounded by the connecting lines between the multiple ends of the notched groove 40.

[0169] At this time, the maximum length of the predetermined pressure relief area 401 along the third direction F3 is L1, L12 = 2d × sinα, where d represents the length of the third straight line segment 414, e represents the length of the fourth straight line segment 416, and the angle between the two third straight line segments 414 at the same end of the second straight line segment 413 is 2α.

[0170] like Fig.15 As shown, in some embodiments, the notched groove 41 includes a fifth straight line segment 417 and two sixth straight line segments 418, the fifth straight line segment 417 is located between the two sixth straight line segments 418, and the ends of the fifth straight line segment 417 are respectively connected to the middle parts of the corresponding sixth straight line segments 418, and a seventh straight line segment 419 is defined between the ends of the two sixth straight line segments 418 located on the same side of the fifth straight line segment 417, and the outer edges of the orthographic projections of the seventh straight line segment 419 and the sixth straight line segment 418 in the second direction F2 constitute a predetermined opening boundary of the predetermined pressure relief area 401, that is, the predetermined opening boundary is jointly surrounded by the connecting lines between the multiple ends of the notched groove 40 and the outer edges of the orthographic projections of a part of the notched groove 40 in the second direction.

[0171] Of course, a flip notch 419 can be set in the notch groove 41 at the seventh straight segment 419, thereby correspondingly setting two flip notches 419, and the two flip notches 419 are located on both sides of the fifth straight segment 417. The setting of the flip notch 419 is conducive to the pressure relief part 40 to relieve pressure along the predetermined opening boundary, thereby ensuring the effectiveness of the pressure relief area.

[0172] At this time, the maximum length of the predetermined pressure relief area 401 along the third direction F3 is L1, L1=k, where k represents the length of the seventh straight line segment 419 .

[0173] The notched groove 41 of the above structure is adopted to facilitate rapid pressure relief of the pressure relief portion 40 .

[0174] The battery 1000 according to the second aspect of the present application includes the battery cell 100 according to the first aspect of the present application.

[0175] The electric device according to the third aspect of the present application includes the battery 1000 according to the second aspect of the present application, and the battery 1000 is used to provide electric energy for the electric device. Therefore, by using the battery 1000, it is beneficial to improve the safety and reliability of the electric device.

[0176] Alternatively, if Figure 1 As shown, when the battery 1000 is used in a vehicle, the battery 1000 can be arranged at the bottom, head, or tail of the vehicle. The battery 1000 can be used to power the vehicle, for example, the battery 1000 can be used as an operating power source for the vehicle. The vehicle can also include a controller and a motor, and the controller is used to control the battery 1000 to power the motor, for example, for starting, navigating, and driving the vehicle.

[0177] A battery 1000 and a vehicle 2000 having the same according to a specific embodiment of the present application will be described below with reference to the accompanying drawings.

[0178] like Figure 1 As shown, the battery 1000 is disposed at the bottom of the vehicle 2000, and as shown in FIG. Figure 2 As shown, the battery 1000 includes a plurality of battery cells 100. Figure 3 and Figure 4 As shown, each battery cell 100 includes a housing 10 and an electrode assembly 20 .

[0179] The electrode assembly 20 is arranged in the outer shell 10, and the electrode assembly 20 includes at least one positive electrode sheet and at least one negative electrode sheet. The at least one positive electrode sheet and the at least one negative electrode sheet are stacked to form a straight area, and at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked in the straight area along a first direction F1.

[0180] like Figure 3and Figure 4 As shown, the shell 10 can be roughly in the shape of a quadrangular prism, with a simple structure and easy to form. The shell 10 is provided with an electrical connection portion 30 and a pressure relief portion 40. The shell 10 includes a shell body 101 and an end cover 102. The electrical connection portion 30 is arranged on the end cover 102. The shell body 101 has a first wall portion 11 and two oppositely arranged second wall portions 12. The first wall portion 11 is located at the bottom of the shell body 101. The pressure relief portion 40 is arranged on the first wall portion 11. The pressure relief portion 40 has a notched groove 41. The notched groove 41 defines a predetermined pressure relief area 401 that is opened when the battery cell 100 is depressurized.

[0181] Therefore, the electrical connection part 30 and the pressure relief part 40 are located on different sides of the outer shell 10, which can shorten the distance between the pressure relief part 40 and the main body of the electrode assembly 20. Therefore, when the battery cell 100 thermally runs away, most of the discharge medium in the outer shell 10 can flow directly from the edge of the main body of the electrode assembly 20 to the pressure relief part 40, thereby shortening the path of the discharge medium flowing to the pressure relief part 40, allowing the discharge medium to flow quickly to the pressure relief part 40, shortening the time for the discharge medium to reach the pressure relief part 40, and improving the timeliness of the pressure relief of the battery cell 100, thereby effectively improving the reliability of the battery cell 100.

[0182] like Fig.11 As shown, the first wall portion 11 has a thinning area 60, which can be formed by a grooving process or a stamping process. The upper surface of the thinning area 60 is flush with the inner surface of the first wall portion 11, and the lower surface of the thinning area 60 is located on the inner side of the outer surface of the first wall portion 11. A portion of the thinning area 60 is arched outward to form a redundant portion 50. The cross-section of the redundant portion 50 is arc-shaped, and the projection of the redundant portion 50 on the first wall portion 11 is runway-shaped. The redundant portion 50 surrounds the outer periphery of the predetermined pressure relief area 401 formed by the notched groove 41, and the maximum height H of the redundant portion 50 is 1 mm, and the maximum width of the redundant portion 50 is 2 mm.

[0183] In some examples, the sum of the maximum height of the redundant portion 50 and the thickness of the thinned area 60 is less than or equal to the maximum thickness of the first wall portion 11 , so that the redundant portion 50 does not occupy additional space in the second direction F2 , thereby improving space utilization.

[0184] Therefore, by arranging the redundant part 50 on the outer side of the notched groove 41, when the electrode assembly 20 expands, the expansion force of the electrode assembly 20 can pull the redundant part 50, causing the redundant part 50 to undergo a certain deformation, thereby absorbing at least part of the expansion force of the electrode assembly 20, thereby reducing the expansion force acting on the notched groove 41, thereby reducing the pulling force on the notched groove 41, and the redundant part 50 plays a buffering role, thereby reducing the probability of the notched groove 41 being pulled and damaged, resulting in leakage, thereby improving the service life and reliability of the battery cell 100.

[0185] 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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: Electrode assembly; A housing for accommodating the electrode assembly, the housing being provided with a notched groove, the notched groove defining a predetermined pressure relief area that is opened when the battery cell is depressurized; Wherein, the shell is provided with a redundant portion arched toward a side close to and / or away from the electrode assembly, and the redundant portion is located outside the predetermined pressure relief area.

2. The battery cell according to claim 1, characterized in that: The shell is provided with a thinning area, the minimum thickness of the thinning area is greater than the maximum thickness at the notch groove and the maximum thickness of the thinning area is less than the maximum thickness of the wall of the shell where the thinning area is located, and a part of the thinning area is arched toward and / or away from the side of the electrode assembly to form the redundant part.

3. The battery cell according to claim 2, characterized in that: The notched groove is arranged in the thinning area.

4. The battery cell according to claim 1, characterized in that: Along the direction approaching and / or away from the electrode assembly, the maximum height dimension of the redundant portion is H, and along the direction away from the notch groove, the maximum width dimension of the redundant portion is W, and 0.03≤H / W≤10.

5. The battery cell according to claim 1, characterized in that: Along the direction approaching and / or away from the electrode assembly, the maximum height dimension of the redundant portion is H, and 0.1 mm≤H≤2 mm.

6. The battery cell according to claim 1, characterized in that: Along the direction away from the notch groove, the maximum width dimension of the redundant portion is W, and 0.2 mm≤W≤3 mm.

7. The battery cell according to claim 1, characterized in that: The redundant portion extends along the outer periphery of the predetermined pressure relief area, and the redundant portion has an arc shape in a cross section perpendicular to an extending direction of the redundant portion.

8. The battery cell according to claim 1, characterized in that: The redundant parts are arranged symmetrically along the geometric center of the housing.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The electrode assembly includes at least one positive electrode sheet and at least one negative electrode sheet, wherein the at least one positive electrode sheet and the at least one negative electrode sheet are stacked to form a straight region, and at least a portion of the positive electrode sheet and at least a portion of the negative electrode sheet are stacked in a first direction in the straight region. The shell includes a first wall portion, which is located on one side of the electrode assembly in a second direction, the second direction is a thickness direction of the first wall portion and is perpendicular to the first direction, and the first wall portion is provided with the notch groove and the redundant portion.

10. The battery cell according to claim 9, characterized in that: The redundant portion includes a first redundant segment, and the first redundant segment is located at one side of the score groove in the first direction.

11. The battery cell according to claim 10, characterized in that: The maximum length of the predetermined pressure relief area in the third direction is L1, the maximum slot length of the first redundant segment in the third direction is L2, and the following conditions are satisfied: L2 / L1≥0.9, and the third direction is perpendicular to the first direction and the second direction respectively.

12. The battery cell according to claim 10, characterized in that: The redundant portion includes a second redundant segment, and the second redundant segment is located on one side of the notch groove in a third direction, and the third direction is perpendicular to the first direction and the second direction respectively.

13. The battery cell according to claim 12, characterized in that: The second redundant segment is connected to the first redundant segment.

14. The battery cell according to claim 13, characterized in that: The projection of the second redundant segment on the first wall portion is arc-shaped, and one of the first redundant segments is provided on both sides of the notched groove in the first direction, respectively, and the two first redundant segments are connected by two second redundant segments through arc transition.

15. The battery cell according to claim 2, characterized in that: The housing comprises a pressure relief portion, the pressure relief portion has the notched groove, the pressure relief portion is integrally formed with a wall portion of the housing, and the wall portion of the housing is provided with the thinned area.

16. The battery cell according to claim 2, characterized in that: The shell includes a pressure relief portion, the pressure relief portion has the notched groove, the pressure relief portion is separately arranged from the wall portion of the shell, the pressure relief portion is installed on the wall portion of the shell, the pressure relief portion is provided with the thinning area and / or the wall portion of the shell is provided with the thinning area.

17. The battery cell according to claim 1, characterized in that: The predetermined pressure relief zone has a predetermined opening boundary, and the predetermined opening boundary is surrounded by the outer edge of the orthographic projection of at least a portion of the scored groove in the depth direction of the scored groove; or the predetermined opening boundary is surrounded by the connecting line between multiple ends of the scored groove; or the predetermined opening boundary is jointly surrounded by the connecting line between multiple ends of the scored groove and the outer edge of the orthographic projection of at least a portion of the scored groove in the depth direction of the scored groove.

18. A battery, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 17.

19. An electrical device, characterized in that: The invention comprises a battery according to claim 18, wherein the battery is used to provide electrical energy to the electrical device.

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