Battery monomer, battery and electric device

Abstract

The embodiment of the invention provides a battery monomer, a battery and an electric device. The battery cell comprises: a housing having a first wall provided with a pressure relief mechanism; the electrode assembly is accommodated in the shell; the supporting structure is arranged between the electrode assembly and the first wall and fixedly connected with the first wall, and the supporting structure is used for forming an exhaust channel communicating with the pressure relief mechanism between the first wall and the electrode assembly. According to the battery monomer, the battery and the power utilization device provided by the embodiment of the invention, the possibility of non-directional pressure relief of the battery monomer can be reduced.

Description

Technical Field

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

[0002] In the related art, when a battery cell experiences thermal runaway, the electrode assembly runs the risk of moving toward the first wall of the outer shell on which a pressure relief mechanism is provided, causing the electrode assembly to be pressed against the first wall, thereby blocking the channel for the thermal runaway gas to be discharged from the pressure relief mechanism, thereby causing non-directional pressure relief inside the battery cell. Summary of the invention

[0003] In view of this, the embodiments of the present application provide a battery cell, a battery, and an electrical device, which can reduce the possibility of non-directional pressure release in the battery cell.

[0004] In a first aspect, a battery cell is provided, comprising: an outer shell having a first wall, the first wall being provided with a pressure relief mechanism; an electrode assembly accommodated in the outer shell; a support structure, arranged between the electrode assembly and the first wall and fixedly connected to the first wall, the support structure being used to form an exhaust channel between the first wall and the electrode assembly that is connected to the pressure relief mechanism.

[0005] In this embodiment, a support structure is provided between a first wall provided with a pressure relief mechanism and the electrode assembly, and the support structure is fixed on the first wall to form an exhaust passage connected to the pressure relief mechanism between the first wall and the electrode assembly. When thermal runaway occurs in the battery cell, the thermal runaway gas can be promptly discharged to the outside of the battery cell through the pressure relief mechanism, thereby reducing the possibility of non-directional pressure relief in the battery cell.

[0006] In a possible implementation, the support structure is used to support the electrode assembly.

[0007] In this embodiment, the support structure is used to support the electrode assembly, which is beneficial for forming an exhaust channel connected to the pressure relief mechanism between the first wall and the electrode assembly when thermal runaway occurs in the battery cell, thereby improving the problem of non-directional pressure relief in the battery cell.

[0008] In a possible implementation, the melting point of the support structure is greater than 100°C.

[0009] In this embodiment, a support structure with a melting point greater than 100°C is used, which is advantageous in that the battery cell is not easily melted when thermal runaway occurs, thereby being able to form an exhaust channel connected to the pressure relief mechanism between the first wall and the electrode assembly, so that the thermal runaway gas can be discharged to the outside of the battery cell through the pressure relief mechanism in a timely manner, thereby improving the problem of non-directional pressure relief of the battery cell.

[0010] In a possible implementation, the battery cell further includes: an insulating member disposed between the electrode assembly and the first wall; wherein the insulating member is provided with an escape cavity, and the escape cavity is used to accommodate the support structure.

[0011] In this embodiment, by providing an avoidance cavity on the insulating component to accommodate the support structure, the insulation between the first wall and the electrode assembly does not need to be affected, and there is no need to occupy additional space of the battery cell in the thickness direction of the first wall, thereby improving the energy density of the battery cell.

[0012] In a possible implementation, the battery cell further includes an insulating member, the insulating member is used to insulate the first wall and the electrode assembly, and the melting point of the supporting structure is higher than the melting point of the insulating member.

[0013] In this embodiment, by setting the melting point of the support structure higher than the melting point of the insulating component, the support structure is not easily melted in the later stage of thermal runaway, and an exhaust channel can be provided for the thermal runaway gas to reach the pressure relief mechanism, thereby reducing the probability of non-directional pressure relief of the battery cell.

[0014] In a possible implementation manner, the support structure is fixedly connected to the first wall by welding.

[0015] In this embodiment, the support structure and the first wall are fixedly connected by welding, so as to enhance the bonding strength between the support structure and the first wall.

[0016] In a possible implementation manner, the support structure and the first wall are integrally formed.

[0017] In this embodiment, the support structure and the first wall are integrally formed, which can improve the bonding strength between the first wall and the support structure, thereby reducing the shaking of the support structure in the battery cell and reducing the probability of the support structure blocking the pressure relief mechanism.

[0018] In a possible implementation, an insulating layer is provided on a surface of the support structure facing the electrode assembly.

[0019] In this embodiment, an insulating layer is provided on the surface of the support structure facing the electrode assembly, which can reduce the probability of electrical connection between the first wall and the electrode assembly.

[0020] In a possible implementation manner, the material of the support structure is the same as the material of the first wall.

[0021] In this embodiment, the material of the support structure is set to be the same as the material of the first wall, which can improve the workability of fixing the support structure on the first wall.

[0022] In a possible implementation, in a first direction, there is a gap between the shell and the electrode assembly; the support structure is provided with a cavity penetrating along the first direction, the cavity is used to conduct the pressure relief mechanism and the gap, and the first direction is perpendicular to the thickness direction of the first wall.

[0023] In this embodiment, the support structure is provided with a cavity penetrating along the first direction, which is used to connect the gap and the pressure relief mechanism, so as to guide the thermal runaway gas accumulated in the gap to the pressure relief mechanism, thereby reducing the possibility that the thermal runaway gas accumulated in the gap will not be exhausted in time and cause the shell to be broken. In addition, by providing the cavity in the support structure, it can also achieve the effect of reducing weight and improving energy density.

[0024] In a possible implementation, the support structure includes a first connecting wall and at least one supporting wall that are connected to each other, the first connecting wall is fixedly connected to the first wall, and the supporting wall is perpendicular to the first connecting wall.

[0025] In this embodiment, by adopting a support structure formed by a first connecting wall fixedly connected to the first wall and at least one supporting wall perpendicular to the first connecting wall, the weight of the battery cell can be reduced and the energy density of the battery cell can be improved.

[0026] In a possible implementation, the at least one supporting wall includes two supporting walls arranged opposite to each other along a second direction, the second direction is perpendicular to a thickness direction of the first wall, and the second direction is perpendicular to the first direction.

[0027] In this embodiment, a cavity penetrating along the first direction is formed by two supporting walls arranged opposite to each other along the second direction and the first connecting wall, so that the ventilation cross-sectional area can be increased as much as possible while the supporting strength is enhanced, thereby improving the exhaust rate of the thermal runaway gas.

[0028] In a possible implementation, the two support walls are respectively connected to the two ends of the first connecting wall along the second direction, the support wall includes a first part perpendicular to the second direction and a second part parallel to the first connecting wall, the first part is connected to the first connecting wall, and the two second parts of the two support walls are spaced apart along the second direction.

[0029] In this embodiment, the supporting wall includes not only a first portion perpendicular to the second direction, but also a second portion parallel to the first connecting wall, and the two second portions of the supporting structure are spaced apart along the second direction, which can enhance the strength of the supporting structure.

[0030] In a possible implementation manner, in the thickness direction of the first wall, a projection of the second part on the first wall is located within a projection of the first connecting wall on the first wall.

[0031] In this embodiment, the two supporting walls are respectively connected to the two ends of the first connecting wall along the second direction, and in the thickness direction of the first wall, the projection of the second part on the first wall is located within the projection of the first connecting wall on the first wall, which can more effectively increase the ventilation cross-sectional area of ​​the supporting structure.

[0032] In a possible implementation manner, in the thickness direction of the first wall, a projection of the second part on the first wall is located outside a projection of the first connecting wall on the first wall.

[0033] In this embodiment, the two supporting walls are respectively connected to the two ends of the first connecting wall along the second direction, and in the thickness direction of the first wall, the projection of the second part on the first wall is located outside the projection of the first connecting wall on the first wall, so that the supporting structure is more manufacturable.

[0034] In a possible implementation, the support structure further includes a second connecting wall, which is arranged opposite to the first connecting wall along the thickness direction of the first wall, and the first connecting wall, the second connecting wall and the two supporting walls are connected end to end to form a cavity.

[0035] In this embodiment, the support structure is formed by a first connecting wall, two supporting walls and a second connecting wall connected end to end, which can enhance the strength of the support structure and thus improve the support for the electrode assembly.

[0036] In a possible implementation manner, the support structure is disposed at an end region of the battery cell along the first direction.

[0037] In this embodiment, the support structure is arranged at the end area of ​​the first wall along the first direction, which can minimize the possibility of the first wall at the end in the first direction abutting against the electrode assembly, so that the thermal runaway gas in the battery cell can reach the pressure relief mechanism, reducing the possibility of non-directional pressure relief in the battery cell.

[0038] In a possible implementation manner, in a first direction, the pressure relief mechanism is disposed between two supporting structures, and the first direction is perpendicular to a thickness direction of the first wall.

[0039] In this embodiment, in the first direction, the pressure relief mechanism is arranged between the two supporting structures, which can minimize the possibility of the end of the first wall abutting against the electrode assembly, so that the thermal runaway gas in the two side chamber cavities of the battery cell in the first direction can be discharged to the pressure relief mechanism through the corresponding supporting structures, further reducing the possibility of non-directional pressure relief of the battery cell.

[0040] In a possible implementation manner, the support structure is disposed in a middle region of the end region in a second direction, the second direction is perpendicular to a thickness direction of the first wall, and the second direction is perpendicular to the first direction.

[0041] In this embodiment, by arranging the support structure in the middle area of ​​the end area in the second direction, when the shell is severely deformed, the thermal runaway gas accumulated in the side chamber cavity of the battery cell in the first direction can be discharged to the pressure relief mechanism as much as possible, thereby reducing the possibility of non-directional pressure relief of the battery cell.

[0042] In a possible implementation manner, the support structure is disposed in an edge region of the end region in a second direction, the second direction is perpendicular to a thickness direction of the first wall, and the second direction is perpendicular to the first direction.

[0043] In this embodiment, by arranging the support structure in the edge area of ​​the end area in the second direction, the thermal runaway gas accumulated in the side chamber cavity of the battery cell in the first direction can be discharged to the pressure relief mechanism as much as possible without serious deformation of the shell, thereby reducing the possibility of non-directional pressure relief of the battery cell.

[0044] In a possible implementation, in the thickness direction of the first wall, a dimension h of the support structure and a dimension c of the battery cell satisfy: 0.003≤h / c≤0.13.

[0045] In this embodiment, if h / c is less than 0.003, it is very easy to be blocked by particulate matter or pole pieces generated by the loss of control inside the battery cell, thereby failing to achieve the purpose of forming an exhaust channel; and when h / c is greater than 0.13, the energy density of the battery cell will be seriously sacrificed; setting h / c between 0.003 and 0.13 can achieve the purpose of balancing the energy density of the battery cell and forming an exhaust channel between the first wall and the electrode assembly.

[0046] In one possible implementation, the first wall and the electrode assembly are provided with at least one supporting structure, and in the thickness direction of the first wall, the at least one supporting structure satisfies the following relationship between the total projected area S1 of the first wall and the area S of the first wall: 0.012≤S1 / S≤0.26.

[0047] In this embodiment, when S1 / S is less than 0.012, when thermal runaway occurs in the battery cell, the contact area between the support structure and the first wall is too small, which cannot provide sufficient mechanical support for the electrode assembly, which may cause the internal electrode assembly to shake or overlap with the first wall, and even further deteriorate the exhaust path; and when S1 / S is greater than 0.26, on the one hand, the weight of the battery cell will increase, sacrificing energy density, and on the other hand, the support structure will further reduce the internal free space of the battery cell, which is not conducive to directional pressure relief. Setting S1 / S between 0.012 and 0.26 can achieve the purpose of balancing the energy density of the battery cell and forming an exhaust channel between the first wall and the electrode assembly.

[0048] In a possible implementation manner, the first wall is an end cover.

[0049] In this embodiment, the support structure and the end cover are fixed together. Compared with fixing the support structure to other walls of the shell, the support structure and the end cover can be fixed together externally, or the support structure can be directly formed when preparing the end cover, without extending the support structure into the shell for fixing, thereby improving the preparation efficiency of the battery cell.

[0050] In a possible implementation, the battery cell further includes: an electrode terminal disposed on the first wall; and the electrode terminal is electrically connected to the electrode assembly.

[0051] In this embodiment, by providing electrical connection between the electrode terminal of the first wall and the electrode assembly, electrical connection with other battery cells can be achieved, thereby achieving the purpose of expanding the battery capacity.

[0052] In a second aspect, a battery is provided, comprising the battery cell in the first aspect and any possible implementation manner of the first aspect.

[0053] In a third aspect, an electrical device is provided, comprising the battery in the second aspect, wherein the battery is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0055] Figure 1 It is a structural schematic diagram of a vehicle disclosed in one embodiment of the present application.

[0056] Figure 2 It is a schematic diagram of the structure of a battery disclosed in one embodiment of the present application.

[0057] Figure 3 It is a schematic diagram of an exploded view of a battery cell disclosed in an embodiment of the present application.

[0058] Figure 4 It is a planar cross-sectional view of a battery cell disclosed in one embodiment of the present application.

[0059] Figure 5 It is a partial cross-sectional view of a battery cell disclosed in yet another embodiment of the present application.

[0060] Figure 6 It is a schematic diagram of the connection between the first wall and the supporting structure disclosed in the embodiment of the present application.

[0061] Figure 7 It is another planar cross-sectional view of a battery cell disclosed in an embodiment of the present application.

[0062] Figure 8 It is a structural schematic diagram of a support structure disclosed in an embodiment of the present application.

[0063] Fig. 9 It is a structural schematic diagram of a support structure disclosed in another embodiment of the present application.

[0064] Fig.10 It is a structural schematic diagram of a support structure disclosed in yet another embodiment of the present application.

[0065] Fig.11 A top view of a first wall disclosed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0066] 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.

[0067] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field to which this application belongs; 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" and any variations thereof in the specification and claims of this application and the above-mentioned drawings 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.

[0068] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0069] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations 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. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0070] 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.

[0071] The term "multiple" as used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0072] 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.

[0073] 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.

[0074] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set 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.

[0075] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0076] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0077] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., treated with silver surface, may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0078] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0079] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0080] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0081] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0082] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0083] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.

[0084] In some embodiments, the negative electrode may be a foam metal. The foam metal may be foam nickel, foam copper, foam aluminum, foam alloy, or foam carbon, etc. When the foam metal is used as the negative electrode plate, the surface of the foam metal may not be provided with a negative electrode active material, but of course, a negative electrode active material may also be provided.

[0085] As an example, the negative electrode current collector may also be filled with or / and deposited with a lithium source material, potassium metal or sodium metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0086] 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.

[0087] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0088] 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.

[0089] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0090] 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.

[0091] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of 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.

[0092] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0093] In some embodiments, the electrode assembly is a laminate structure.

[0094] 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.

[0095] 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.

[0096] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded sections.

[0097] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0098] As an example, the separator may be disposed continuously, and disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0099] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0100] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0101] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film. The housing includes a shell and a cover plate.

[0102] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] At present, when a battery cell experiences internal or external short circuit due to mechanical external force or other reasons, it may lead to thermal runaway of the battery cell. A large amount of thermal runaway gas will be generated inside instantly. The generated gas needs to pass through the electrode assembly and its mechanical parts inside the battery cell to reach the pressure relief mechanism, and open the pressure relief mechanism through the internal and external pressure difference, thereby achieving directional pressure relief.

[0108] However, as the energy density of battery cells continues to increase, the thermal runaway rate of battery cells continues to increase, and the gas production rate and gas production volume increase significantly. Under the current battery cell design, non-directional pressure relief may occur during thermal runaway. For example, the exhaust passage in the battery cell that reaches the pressure relief mechanism is blocked, causing damage to the shell and gas pressure relief from the damaged part. This phenomenon will cause secondary disasters of verification at the system level, such as impacting adjacent battery cells to cause heat diffusion, and impacting high-voltage wiring harnesses to cause high-voltage ignition.

[0109] In view of this, an embodiment of the present application provides a battery cell, which provides a support structure between a first wall provided with a pressure relief mechanism and an electrode assembly, and fixes the support structure on the first wall, so that the support structure can form an exhaust channel between the first wall and the electrode assembly to guide the thermal runaway gas to the pressure relief mechanism, and then the thermal runaway gas can be discharged to the outside of the battery cell through the pressure relief mechanism in time, thereby reducing the possibility of non-directional pressure relief in the battery cell.

[0110] The technical solutions described in the embodiments of the present application are applicable to various devices that use batteries, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, electric tools, electric vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0111] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the devices described above, but can also be applied to all devices using batteries. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0112] For example, Figure 1 As shown, it is a structural schematic diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A motor 80, a controller 60 and a battery 100 may be arranged inside the vehicle 1. The controller 60 is used to control the battery 100 to supply power to the motor 80. For example, a battery 100 may be arranged at the bottom, front or rear of the vehicle 1. The battery 100 may be used to supply power to the vehicle 1. For example, the battery 100 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery 100 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0113] For example, Figure 2, which is a schematic diagram of the structure of a battery 100 according to an embodiment of the present application. The battery 100 may include a plurality of battery cells 20. In addition to the battery cells 20, the battery 100 may also include a box body, the interior of the box body is a hollow structure, and the plurality of battery cells 20 may be accommodated in the box body. Figure 2 As shown, the box body may include two parts, which are respectively referred to as a first box body part 111 and a second box body part 112, and the first box body part 111 and the second box body part 112 are buckled together. The shapes of the first box body part 111 and the second box body part 112 may be determined according to the shapes of the combination of multiple battery cells 20, and at least one of the first box body part 111 and the second box body part 112 has an opening. For example, Figure 2 As shown, only one of the first box body 111 and the second box body 112 is a hollow cuboid with an opening, and the other is in a plate shape to cover the opening. Here, taking the second box body 112 as a hollow cuboid with only one face as an opening face, and the first box body 111 as a plate-shaped example, the first box body 111 covers the opening of the second box body 112 to form a box body 11 with a closed chamber, which can be used to accommodate multiple battery cells 20. After the multiple battery cells 20 are connected in parallel, in series or in mixed series, they are placed in the box body formed by the first box body 111 and the second box body 112 being buckled together.

[0114] For example, unlike Figure 2 As shown, the first box body 111 and the second box body 112 can both be hollow cuboids and each have only one open face, the opening of the first box body 111 and the opening of the second box body 112 are arranged opposite to each other, and the first box body 111 and the second box body 112 are buckled together to form a box with a closed chamber. A plurality of battery cells 20 are connected in parallel, in series or in a mixed combination and are placed in the box formed by the first box body 111 and the second box body 112 buckled together.

[0115] In some embodiments, the battery 100 may also include other structures, which are not described one by one here. For example, the battery 100 may also include a busbar component (not shown in the figure), which is used to realize the electrical connection between multiple battery cells 20. Specifically, the busbar component can realize the electrical connection between the battery cells 20 by connecting the electrode terminals of the battery cells 20. In some embodiments, the busbar component can be fixed to the electrode terminals of the battery cells 20 by welding. The electrical energy of multiple battery cells 20 can be further led out through the box through the conductive mechanism. In some embodiments, the conductive mechanism may also belong to the busbar component.

[0116] In order to meet different power requirements, the number of battery cells 20 can be multiple, and multiple battery cells can be connected in series, in parallel, or in hybrid connection, where hybrid connection refers to a mixture of series and parallel connection. Battery 100 can also be called a battery pack. In some embodiments, multiple battery cells can be connected in series, in parallel, or in hybrid connection to form a battery module, and multiple battery modules can be connected in series, in parallel, or in hybrid connection to form battery 100. In other words, multiple battery cells can directly form battery 100, or they can first form battery modules, and then the battery modules can form battery 100.

[0117] Figure 3 A schematic exploded view of a battery cell 20 according to an embodiment of the present application is shown.

[0118] like Figure 3 As shown, the battery cell 20 includes one or more electrode assemblies 22, a shell 211 and a cover plate 212, wherein the wall of the shell 211 and the cover plate 212 are both referred to as the wall of the battery cell 20. The shell 211 is determined according to the shape of the one or more electrode assemblies 22 after being combined. For example, the shell 211 may be a hollow cuboid or a cube or a cylinder, and one of the faces of the shell 211 has an opening so that one or more electrode assemblies 22 can be placed in the shell 211. For example, when the shell 211 is a hollow cuboid or a cube, one of the planes of the shell 211 is an open face, that is, the plane does not have a wall body so that the inside and outside of the shell 211 are connected. When the shell 211 may be a hollow cylinder, the end face of the shell 211 is an open face, that is, the end face does not have a wall body so that the inside and outside of the shell 211 are connected. The cover plate 212 covers the opening and is connected to the shell 211 to form a closed cavity for placing the electrode assembly 22. The housing 211 is filled with an electrolyte, such as an electrolyte solution.

[0119] The battery cell 20 also includes two electrode terminals 214. The cover plate 212 is generally in the shape of a flat plate, and the two electrode terminals 214 are fixed on the flat surface of the cover plate 212. The two electrode terminals 214 are respectively a positive electrode terminal 214a and a negative electrode terminal 214b. Each electrode terminal 214 is provided with a corresponding connection member 23, or it can also be called a current collecting member, which is located between the cover plate 212 and the electrode assembly 22, and is used to electrically connect the electrode assembly 22 and the electrode terminal 214.

[0120] like Figure 3As shown, each electrode assembly 22 has a first pole tab 221a and a second pole tab 222a. The polarities of the first pole tab 221a and the second pole tab 222a are opposite. For example, when the first pole tab 221a is a positive pole tab, the second pole tab 222a is a negative pole tab. The first pole tab 221a of one or more electrode assemblies 22 is connected to an electrode terminal 214 through a connecting member 23, and the second pole tab 222a of one or more electrode assemblies 22 is connected to another electrode terminal 214 through another connecting member 23. For example, the first pole tab 221a is a positive pole tab, the second pole tab 222a is a negative pole tab, the positive electrode terminal 214a is connected to the first pole tab 221a through a connecting member 23, and the negative electrode terminal 214b is connected to the second pole tab 222a through another connecting member 23.

[0121] In the battery cell 20, the electrode assembly 22 can be provided as a single electrode assembly or multiple electrode assemblies according to actual use requirements. Figure 3 As shown, four independent electrode assemblies 22 are disposed in the battery cell 20 .

[0122] As an example, a pressure relief mechanism 213 may be further provided on one wall of the battery cell 20. The pressure relief mechanism 213 is used to be actuated to release the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a threshold.

[0123] Optionally, the pressure relief mechanism 213 may be disposed on the cover plate 212 , or on any wall of the housing 211 .

[0124] Figure 4 A plan cross-sectional view of a battery cell 30 according to an embodiment of the present application is shown.

[0125] like Figure 4 The battery cell 30 includes: a shell 31, having a first wall 311, on which a pressure relief mechanism 312 is arranged; an electrode assembly 32, accommodated in the shell 31; a support structure 33, arranged between the first wall 311 and the electrode assembly 32, and the support structure 33 is fixedly connected to the first wall 311, and the support structure 33 is used to form an exhaust channel A between the first wall 311 and the electrode assembly 32 that is connected to the pressure relief mechanism 312.

[0126] It should be explained that the housing 31 may include Figure 3 In the housing 211 and the cover plate 212 shown, the first wall 311 can be any wall of the housing 211 or the cover plate 212 . In other words, the pressure relief mechanism 213 can be disposed on any wall of the battery cell 30 .

[0127] The support structure 33 is disposed between the first wall 311 and the electrode assembly 32, and the support structure 33 is fixedly connected to the first wall 322. It can be understood that the support structure 33 is fixed to the surface of the first wall 311 facing the electrode assembly 32, for example, Figure 4 As shown, the support structure 33 is fixed to the lower surface of the first wall 311 .

[0128] The support structure 33 is used to form an exhaust channel A between the first wall 311 and the electrode assembly 32, which is connected to the pressure relief mechanism 312. Specifically, when thermal runaway occurs in the battery cell 30, the support structure 33 can separate the first wall 311 and the electrode assembly 32, and form an exhaust channel A between the first wall 311 and the electrode assembly 32. The exhaust channel A can guide the thermal runaway gas to the pressure relief mechanism 312, so that the thermal runaway gas is discharged from the pressure relief mechanism 312 to the outside of the battery cell 30.

[0129] In this embodiment, the support structure 33 is arranged between the first wall 311 and the electrode assembly 32, and the support structure 33 is fixed to the first wall 311, and is used to form an exhaust channel A between the first wall 311 and the electrode assembly 32 that is connected to the pressure relief mechanism 312, so that when the battery cell 30 has thermal runaway, there is a gap between the first wall 311 and the electrode assembly 32, so that the thermal runaway gas can be accommodated, and because the pressure relief mechanism 312 is arranged on the first wall 311, the thermal runaway gas accumulated in the gap between the first wall 311 and the electrode assembly 32 can be discharged from the pressure relief mechanism 312 to the outside of the battery cell 30, thereby reducing the possibility of non-directional pressure relief of the battery cell 30.

[0130] In some embodiments, the support structure 33 is used to support the electrode assembly 32 .

[0131] In other words, the support structure 33 may restrict the electrode assembly 32 from moving toward the first wall 311 .

[0132] For example, the support structure 33 is used to support the electrode assembly 32 when the battery cell 30 has thermal runaway. For another example, the support structure 33 can support the electrode assembly 32 regardless of whether the battery cell 30 has thermal runaway. The embodiment of the present application is not limited to this.

[0133] In this embodiment, the support structure 33 is used to support the electrode assembly 32, which is beneficial for forming an exhaust channel A connected to the pressure relief mechanism 312 between the first wall 311 and the electrode assembly 32 when thermal runaway occurs in the battery cell 30, thereby improving the problem of non-directional pressure relief of the battery cell 30.

[0134] In some other embodiments, the melting point of the support structure 33 is greater than 100°C.

[0135] In an example, the material of the support structure 33 may be a single material, for example, the material of the support structure 33 is a single material such as aluminum material or copper material. In this case, the support structure 33 has a fixed melting point.

[0136] In another example, the material of the support structure 33 may be a composite material. For example, the support structure 33 may be a mixed material of aluminum material and copper material. In this case, the support structure 33 does not have a fixed melting point, that is, the melting point of the support structure 33 is the melting point range of various materials. For example, the melting point of aluminum material is 660°C, and the melting point of copper is 1083°C, then the melting point range of the support structure 33 is 660°C to 1083°C, and the melting point of the support structure 33 is higher than the melting point of the insulating member 34. It can be understood that the lowest melting point in the melting point range of the support structure 33 is higher than the melting point of the insulating member 34.

[0137] For example, when the positive electrode material of the battery cell is a compound with an olivine structure, the melting point of the support structure 33 can be greater than 150°C, so that the thermal runaway gas can smoothly reach the pressure relief mechanism 312 before the pressure relief mechanism 312 opens the valve. Further optionally, the melting point of the support structure 33 is greater than 500°C, so that the battery cell 30 can still maintain mechanical strength during the thermal runaway process. Among them, the compound with an olivine structure can be selected from lithium iron phosphate, lithium iron manganese phosphate, or a mixture of lithium iron phosphate and lithium iron manganese phosphate.

[0138] For another example, for the positive electrode material of the battery cell containing a layered compound, the melting point of the support structure 33 can be greater than 100°C, so that the thermal runaway gas can smoothly reach the pressure relief mechanism 312 before the pressure relief mechanism 312 opens the valve. Further optionally, the melting point of the support structure 33 is greater than 400°C, so that the battery cell 30 can still maintain mechanical strength during thermal runaway. Among them, the layered compound can be selected from lithium nickel cobalt manganese oxygen ternary layered materials, or a mixture of lithium iron phosphate and lithium nickel cobalt manganese oxygen ternary layered materials, or a mixture of lithium manganese iron and lithium nickel cobalt manganese oxygen ternary layered materials.

[0139] Optionally, the material of the support structure 33 may be a high temperature resistant material. For example, the material of the support structure 33 may include at least one hard material selected from metal, graphite, polytetrafluoroethylene, mica, ceramics and the like.

[0140] In this embodiment, a support structure 33 with a melting point greater than 100°C is used, which is advantageous in that the battery cell 30 is not easily melted when thermal runaway occurs, thereby being able to form an exhaust channel A connected to the pressure relief mechanism 312 between the first wall 311 and the electrode assembly 32, so that the thermal runaway gas can be discharged to the outside of the battery cell 30 through the pressure relief mechanism 312 in a timely manner, thereby improving the problem of non-directional pressure relief of the battery cell 30.

[0141] Figure 5 FIG. 2 shows a partial cross-sectional view of a battery cell 30 according to another embodiment of the present application. Figure 5 As shown, the battery cell 30 further includes: an insulating member 34 disposed between the electrode assembly 32 and the first wall 311 , wherein the insulating member 34 is provided with an escape cavity 341 , and the escape cavity 341 is used to accommodate the support structure 33 .

[0142] Generally, the insulating member 34 is disposed between the first wall 311 and the electrode assembly 32 to insulate the first wall 311 and the electrode assembly 32. Optionally, the insulating member 34 may include polypropylene (PP), polyphenylene sulfide (PPS), or soluble polytetrafluoroethylene (PFA).

[0143] Optionally, the insulating member 34 may be provided with an escape cavity 341 opening toward the first wall 311 , so that the support structure 33 fixed to the surface of the first wall 311 facing the electrode assembly 32 may be accommodated in the escape cavity 341 .

[0144] In this embodiment, by providing an avoidance cavity 341 on the insulating member 34 to accommodate the support structure 33, it is possible to increase the energy density of the battery cell 30 without occupying additional space of the battery cell 30 in the thickness direction Z of the first wall 311 without affecting the insulation between the first wall 311 and the electrode assembly 32.

[0145] Optionally, the melting point of the support structure 33 is higher than the melting point of the insulating member 34 .

[0146] Generally, in the later stage of thermal runaway, the insulating member 34 may be melted, which will cause the electrode assembly 32 to move toward the first wall 311, or even to abut against the first wall 311. This blocks the exhaust passage of the thermal runaway gas from reaching the pressure relief mechanism 312. In this embodiment, by setting the melting point of the support structure 33 to be higher than the melting point of the insulating member 34, the support structure 33 is not easily melted in the later stage of thermal runaway, and can provide an exhaust passage A for the thermal runaway gas to reach the pressure relief mechanism 312, thereby reducing the probability of non-directional pressure relief of the battery cell 30.

[0147] Optionally, the material of the support structure 33 is the same as that of the first wall 311 .

[0148] It should be noted that the support structure 33 may include a variety of materials, for example, its main structure is a metal material, and the outer surface is wrapped with an insulating material. Similarly, the first wall 311 may also include a variety of materials, for example, its main structure is a metal material, and the first wall 311 may also be provided with some components made of insulating materials. In this case, the material of the support structure 33 in the embodiment of the present application is the same as the material of the first wall 311, which actually means that the material of the main structure of the support structure 33 is the same as the material of the main structure of the first wall 311. In addition, if the material of the main structure of the support structure 33 is the same as the material of the main structure of the first wall 311, and both are composite materials, it can be considered that the types of materials included in the two are the same, and the material ratios may be different.

[0149] In some embodiments, the material of the first wall 311 is aluminum, and the material of the support structure 33 may also be aluminum.

[0150] In this embodiment, the material of the support structure 33 is set to be the same as the material of the first wall 311 , which can improve the workability of fixing the support structure 33 on the first wall 311 .

[0151] In an example, the support structure 33 is made of metal material, and the support structure 33 and the first wall 311 can be fixedly connected by welding.

[0152] In this embodiment, the support structure 33 and the first wall 311 are fixedly connected by welding, so as to enhance the bonding strength between the support structure 33 and the first wall 311 .

[0153] Optionally, the support structure 33 and the first wall 311 may also be fixedly connected by riveting or other methods.

[0154] In other embodiments, the material of the support structure 33 may be different from the material of the first wall 311. For example, the material of the support structure 33 may include at least one non-metallic material such as graphite material, polytetrafluoroethylene material, mica or ceramic. In this embodiment, the support structure 33 may be fixedly connected to the first wall 311 by bonding, clamping, etc.

[0155] In other embodiments, the support structure 33 and the first wall 311 may also be integrally formed.

[0156] In this embodiment, the support structure 33 and the first wall 311 are integrally formed, which can improve the bonding strength between the first wall 311 and the support structure 33, thereby reducing the shaking of the support structure 33 in the battery cell 30 and reducing the probability of the support structure 33 blocking the pressure relief mechanism 312.

[0157] Figure 6A schematic diagram showing the connection between the first wall 311 and the support structure 33 according to an embodiment of the present application is shown.

[0158] like Figure 6 As shown, at least the surface of the support structure 33 facing the electrode assembly 32 is provided with an insulating layer 35 .

[0159] It should be noted that when the support structure 33 is made of metal material, an insulating layer 35 needs to be provided on the surface of the support structure 33 ; and when the support structure 33 itself is made of insulating material, an insulating layer 35 does not need to be provided on the surface of the support structure 33 .

[0160] In addition, when the support structure 33 is made of metal material and is accommodated in the avoidance cavity 341 of the insulating component 34, and the avoidance cavity 341 penetrates the insulating component 34 in the thickness direction Z of the first wall 311, the insulating layer 35 can be set only on the surface of the support structure 33 facing the electrode assembly 32; and when the support structure 33 is made of metal material and is accommodated in the avoidance cavity 341 of the insulating component 34, and the avoidance cavity 341 does not penetrate the insulating component 34 in the thickness direction Z of the first wall 311, it is also not necessary to set the insulating layer 35 on the surface of the support structure 33.

[0161] When the support structure 33 is made of metal material and is not surrounded by the insulating member 34 , the insulating layer 35 may be provided on all surfaces of the support structure 33 except the surface fixedly connected to the first wall 311 .

[0162] As an example, an independent insulating layer 35 may be wrapped on the surface of the support structure 33 .

[0163] As another example, a layer of insulating material may be coated on the surface of the support structure 33 to form the insulating layer 35 .

[0164] In this embodiment, an insulating layer 35 is disposed on the surface of the support structure 33 facing the electrode assembly 32 , which can reduce the probability of electrical connection between the first wall 311 and the electrode assembly 32 .

[0165] Alternatively, if Figure 6 and Figure 7 As shown, in the first direction, there is a gap 36 between the housing 31 and the electrode assembly 32. The support structure 33 is provided with a cavity 331 penetrating along the first direction, and the cavity 331 is used to conduct the gap 36 and the pressure relief mechanism 312. The first direction is perpendicular to the thickness direction Z of the first wall 311.

[0166] Optionally, the first direction may be a length direction X of the first wall 311 , or may be a width direction Y of the first wall 311 .

[0167] As an example, in the first direction, the support structure 33 may be disposed between the gap 36 and the pressure relief mechanism 312 .

[0168] In this embodiment, the support structure 33 is provided with a cavity 331 that penetrates along the first direction, which is used to connect the gap 36 and the pressure relief mechanism 312, so as to guide the thermal runaway gas accumulated in the gap 36 to the pressure relief mechanism 312, thereby reducing the possibility that the thermal runaway gas accumulated in the gap 36 will not be exhausted in time and cause the shell 31 to be broken. In addition, by providing the cavity 331 in the support structure 33, it can also achieve the effect of reducing weight and improving energy density.

[0169] In other embodiments, the support structure 33 may not have the cavity 331 , that is, the support structure 33 is a solid structure, as long as the support structure 33 can play a role in supporting the electrode assembly 32 when thermal runaway occurs in the battery cell 30 .

[0170] Optionally, the support structure 33 may also be formed by a plurality of support blocks spaced apart along the second direction, wherein the space between every two adjacent support blocks may form the cavity 331 , that is, may play the role of the cavity 331 .

[0171] The first direction may be the length direction X of the first wall 311 , and the second direction may be the width direction Y of the first wall 311 ; or, the first direction may be the width direction Y of the first wall 311 , and the second direction may be the length direction of the first wall 311 .

[0172] Figure 8 A schematic structural diagram of a support structure 33 according to an embodiment of the present application is shown. Fig. 9 A schematic structural diagram of a support structure 33 according to another embodiment of the present application is shown. Fig.10 A schematic structural diagram of a support structure according to yet another embodiment of the present application is shown.

[0173] Optionally, the supporting structure 33 includes a first connecting wall 332 and at least one supporting wall 333 connected to each other, the first connecting wall 332 is parallel to the first wall 311 , and the first connecting wall 332 is fixedly connected to the first wall 311 , and the supporting wall 333 is perpendicular to the first connecting wall 332 .

[0174] In this embodiment, by using a support structure 33 formed by a first connecting wall 332 fixedly connected to the first wall 311 and at least one supporting wall 333 perpendicular to the first connecting wall 332 , the weight of the battery cell 30 can be reduced and the energy density of the battery cell 30 can be improved.

[0175] In some embodiments, the support wall 333 may be perpendicular to the first direction. For example, the support structure 33 includes a first connecting wall 332 and a support wall 333 . The first connecting wall 332 and the support wall 333 may be L-shaped. A through hole is provided in the support wall 333 to form a cavity 331 .

[0176] In other embodiments, Figures 8 to 10 As shown, the at least one supporting wall 333 includes two supporting walls 333 arranged opposite to each other along a second direction, the second direction is perpendicular to the thickness direction Z of the first wall 311 , and the second direction is perpendicular to the first direction.

[0177] In this embodiment, two support walls 333 arranged opposite to each other along the second direction and the first connecting wall 332 form a cavity 331 that passes through along the first direction, which can increase the ventilation cross-sectional area as much as possible while enhancing the support strength, thereby improving the exhaust rate of the thermal runaway gas.

[0178] like Figure 8 and Fig. 9 As shown, the two support walls 333 are respectively connected to the two ends of the first connecting wall 332 along the second direction, and the support wall 333 includes a first part 3331 perpendicular to the second direction and a second part 3332 parallel to the first connecting wall 332. The first part 3331 is connected to the first connecting wall 332, and the two second parts 3332 of the two support walls 333 are spaced apart along the second direction.

[0179] In this embodiment, the support wall 333 includes not only a first portion 3331 perpendicular to the second direction, but also a second portion 3332 parallel to the first connecting wall 332 , and the two second portions 3332 of the support structure 33 are spaced apart along the second direction, which can enhance the strength of the support structure 33 .

[0180] In some embodiments, the connection points between the two support walls 333 and the first connecting wall 332 may not be located at the two ends of the first connecting wall 332 along the second direction, that is, the connection points between the two support walls 333 and the first connecting wall 332 are respectively at a certain distance from the two ends of the first connecting wall 332 along the second direction.

[0181] In other embodiments, the support wall 333 may include only the first portion 3331 , but not the second portion 3332 .

[0182] like Figure 8 As shown, in the thickness direction Z of the first wall 311 , the projection of the second portion 3332 on the first wall 311 is located within the projection of the first connecting wall 332 on the first wall 311 .

[0183] In this embodiment, the two support walls 333 are respectively connected to the two ends of the first connecting wall 332 along the second direction, and in the thickness direction Z of the first wall 311, the projection of the second part 3332 on the first wall 311 is located within the projection of the first connecting wall 332 on the first wall 311, which can more effectively increase the ventilation cross-sectional area of ​​the support structure 33.

[0184] like Fig. 9 As shown, in the thickness direction Z of the first wall 311 , the projection of the second portion 3332 on the first wall 311 is located outside the projection of the first connecting wall 332 on the first wall 311 .

[0185] In this embodiment, the two supporting walls 333 are respectively connected to the two ends of the first connecting wall 332 along the second direction, and in the thickness direction Z of the first wall 311, the projection of the second part 3332 on the first wall 311 is located outside the projection of the first connecting wall 332 on the first wall 311, so that the supporting structure 33 can be realized by bending, which has stronger manufacturability.

[0186] like Fig.10 As shown, the support structure 33 also includes a second connecting wall 334 . The first connecting wall 332 and the second connecting wall 334 are arranged opposite to each other along the thickness direction of the first wall 311 . The first connecting wall 332 , the two supporting walls 333 and the second connecting wall 334 are connected end to end to form a cavity 331 .

[0187] That is to say, the first connecting wall 332 and the second connecting wall 334 are arranged opposite to each other along the thickness direction Z of the first wall 311, and the two supporting walls 333 are arranged opposite to each other along the second direction. The first connecting wall 332, the two supporting walls 333 and the second connecting wall 334 are connected end to end to form a cavity 331 with a square cross-section.

[0188] In this embodiment, the support structure 33 is formed by a first connecting wall 332 , two supporting walls 333 and a second connecting wall 334 connected end to end, which can enhance the support strength of the support structure 33 to the electrode assembly 32 .

[0189] like Figure 7 As shown, the support structure 33 is disposed at an end region of the battery cell 30 along a first direction, and the first direction is perpendicular to a thickness direction Z of the first wall 311 .

[0190] Typically, when a battery cell 30 experiences thermal runaway, the end of the first wall 311 is more likely to abut against the electrode assembly 32 than the middle region of the first wall 311. Arranging the support structure 33 in the end region of the battery cell 30 along the first direction can minimize the possibility of the end of the first wall 311 in the first direction abutting against the electrode assembly 32, allowing the thermal runaway gas in the battery cell 30 to reach the pressure relief mechanism 312, thereby reducing the possibility of non-directional pressure relief in the battery cell 30.

[0191] Optionally, if the battery cell 30 is a square battery cell, the support structure 33 may be disposed at both ends of the first wall 311 along the length direction X and / or at both ends of the first wall 311 along the width direction Y.

[0192] Optionally, if the battery cell 30 is a cylindrical battery cell, the support structures 33 may be distributed at intervals at the ends of the first wall 311 along the circumference of the first wall 311 .

[0193] Alternatively, if Figure 7 As shown, in the first direction, the pressure relief mechanism 312 is disposed between two support structures 33 .

[0194] In this embodiment, in the first direction, the pressure relief mechanism 312 is arranged between the two support structures 33, which can minimize the possibility of the end of the first wall 311 abutting against the electrode assembly, so that the thermal runaway gas in the two side chamber cavities of the battery cell 30 in the first direction can be discharged to the pressure relief mechanism 312 through the corresponding support structures 33, further reducing the possibility of non-directional pressure relief of the battery cell 30.

[0195] In one example, if Figure 6 As shown, the support structure 33 is arranged in the middle region of the end region in the second direction.

[0196] In this embodiment, by arranging the support structure 33 in the middle area of ​​the end area in the second direction, when the outer shell 31 is severely deformed, the thermal runaway gas accumulated in the side chamber cavity of the battery cell 30 in the first direction can be discharged to the pressure relief mechanism 312 as much as possible, thereby reducing the possibility of non-directional pressure relief of the battery cell 30.

[0197] In another example, the support structure 33 is disposed in an edge region of the end region in the second direction.

[0198] In this embodiment, by arranging the support structure 33 in the edge area of ​​the end area in the second direction, the thermal runaway gas accumulated in the side chamber cavity of the battery cell 30 in the first direction can be discharged to the pressure relief mechanism 312 as much as possible without serious deformation of the outer shell 31, thereby reducing the possibility of non-directional pressure relief of the battery cell 30.

[0199] In one embodiment, the support structure 33 may span the entire electrode assembly 32 in the second direction.

[0200] In another embodiment, the support structure 33 may be disposed only at the four corners of the first wall 311 .

[0201] Alternatively, if Figure 7 As shown, in the thickness direction Z of the first wall 311 , the dimension h of the support structure 33 and the dimension c of the battery cell satisfy: 0.003≤h / c≤0.13.

[0202] In this embodiment, if h / c is less than 0.003, it is very easy to be blocked by particulate matter or pole pieces generated by the loss of control inside the battery cell 30, thereby failing to achieve the purpose of forming the exhaust channel A; and when h / c is greater than 0.13, the energy density of the battery cell 30 will be seriously sacrificed; setting h / c between 0.003 and 0.13 can achieve the purpose of balancing the energy density of the battery cell 30 and forming the exhaust channel A between the first wall 311 and the electrode assembly 32.

[0203] The technical effect achieved by 0.003≤h / c≤0.13 will be described in detail below with reference to specific embodiments.

[0204] Specifically, the size of the battery cell shell is 44mm*220mm*100mm (width*length*height), the energy density is 250Wh / kg, and the end cap (for example, the first wall) with a support structure is manufactured by machine. The end cap has a pressure relief mechanism, wherein the support structure is two regular quadrangular prisms, which are symmetrically distributed and located at the two ends of the short side of the end cap, respectively, with a length of 41mm, and a distance of 0.5mm from the long side of the end cap, and the distance from the support structure to the short side of the end cap is 7mm. Support structures of different heights are made respectively, and then the battery cell is triggered to lose control through the built-in heating film, and the directional pressure relief of the battery cell is observed. The valve opening pressure of the pressure relief mechanism is 1.0MPa, and the end cap weld strength is 1.5MPa; at the same time, the air pressure inside the battery cell is detected through the end cap and the side air pipe, and the data is shown in Table 1.

[0205] Table 1

[0206]

[0207] It can be seen from Table 1 that when h / c = 0.001 and 0.002, the side weld of the shell fails; when h / c = 0.135, the pressure relief mechanism opens normally and the shell is intact, but the energy density loss is serious; and when h / c = 0.003, 0.01, 0.02, 0.05, 0.1 and 0.13, the pressure relief mechanism opens normally and the shell is intact.

[0208] Further optionally, 0.03≤h / c≤0.08.

[0209] Alternatively, if Fig.10 As shown, a plurality of support structures 33 are provided between the first wall 311 and the electrode assembly 32. In the thickness direction Z of the first wall 311, the plurality of support structures 33 satisfy the following relationship between the total projected area S1 of the first wall 311 and the area S of the first wall: 0.012≤S1 / S≤0.26.

[0210] In this embodiment, when S1 / S is less than 0.012, when thermal runaway occurs in the battery cell 30, the contact area between the support structure 33 and the first wall 311 is too small, which cannot provide sufficient mechanical support for the electrode assembly 32, which may cause the internal electrode assembly 32 to shake or overlap with the first wall 311, and even further deteriorate the exhaust path; and when S1 / S is greater than 0.26, on the one hand, the weight of the battery cell will increase, sacrificing energy density, and on the other hand, the free space inside the battery cell 30 occupied by the support structure 33 will be further reduced, which is not conducive to directional pressure relief. Setting S1 / S between 0.012 and 0.26 can achieve the purpose of balancing the energy density of the battery cell 30 and forming an exhaust channel A between the first wall 311 and the electrode assembly 32.

[0211] The technical effect achieved by 0.012≤S1 / S≤0.26 will be described in detail below with reference to specific embodiments.

[0212] Specifically, the size of the battery cell shell is 44mm*220mm*100mm (width*length*height), the energy density is 250Wh / kg, and the end cap (e.g., the first wall) with a support structure is manufactured by machine forging. The end cap has a pressure relief mechanism, wherein the support structure is two regular quadrangular prisms, which are symmetrically distributed and located at the two ends of the short side of the end cap, respectively, with a length of 41mm and a height of 1mm. The width is used as a variable to regulate S1, and then the battery cell is triggered to lose control through the built-in heating film, and the directional pressure relief of the battery cell is observed. The valve opening pressure of the pressure relief mechanism is 1.0MPa, and the end cap weld strength is 1.5MPa; at the same time, the air pressure inside the battery cell is detected through the end cap and the side air pipe, and the data is shown in Table 2.

[0213] Table 2

[0214]

[0215] It can be seen from Table 2 that when S1 / S=0.0042, the end cover weld fails; when S1 / S=0.0085, the side weld fails; when S1 / S==0.3 and 0.31, the side weld fails; and when S1 / S=0.012, 0.013, 0.021, 0.053, 0.11, 0.22 and 0.26, the pressure relief mechanism opens normally and the shell is intact.

[0216] Further optionally, 0.08≤S1 / S≤0.2.

[0217] Alternatively, if Figure 5 As shown, the battery cell 30 further includes: an electrode terminal 37 disposed on the first wall 311 , and the electrode terminal 37 is electrically connected to the electrode assembly 32 .

[0218] In this embodiment, by electrically connecting the electrode terminal 37 provided on the first wall 311 and the electrode assembly 32 , electrical connection with other battery cells can be achieved, thereby achieving the purpose of expanding the battery capacity.

[0219] Optionally, in some embodiments, the electrode terminal 37 may be disposed on a side of the first wall 311 away from the electrode assembly 32 , so as to reduce the internal space occupied by the battery cell 30 and improve the energy density of the battery cell 30 .

[0220] Optionally, the battery cell 30 may be a square battery cell or a cylindrical battery cell. The embodiment of the present application does not limit the shape of the battery cell 30 .

[0221] See again Figures 4 to 10 The battery cell 30 includes: a housing 31 having a first wall 311, on which an electrode terminal 37 and a pressure relief mechanism 312 are arranged; an electrode assembly 32, which is accommodated in the housing 31, and on which the electrode terminal 37 is arranged on a side of the first wall 311 away from the electrode assembly 32; a support structure 33, which is arranged between the electrode assembly 32 and the first wall 311 and is fixedly connected to the first wall 311; an insulating member 34, which is arranged between the first wall 311 and the electrode assembly 32, and on which a avoidance cavity 341 is arranged, which is used to accommodate the support structure 33, and the melting point of the support structure 33 is higher than that of the insulating member 34, and when the battery cell 30 has thermal runaway, the support structure 33 is used to support the electrode assembly 32. In the first direction, there is a gap 36 between the housing 31 and the electrode assembly 32, and the support structure 33 is provided with a cavity 331 which penetrates along the first direction, and the cavity 331 is used to connect the gap 36 and the pressure relief mechanism 312.

[0222] In this embodiment, a support structure 33 is provided between a first wall 311 provided with a pressure relief mechanism 312 and the electrode assembly 32, and the support structure 33 is fixed on the first wall 311, and the support structure 33 is provided with a cavity 331 which passes through along a first direction, so as to guide the thermal runaway gas accumulated in the gap 36 to the exhaust channel A and discharge it to the outside of the battery cell 30 through the pressure relief mechanism 312, thereby reducing the possibility of non-directional pressure relief of the battery cell 30.

[0223] Optionally, the battery cell 30 may further include other components, such as Figure 3 For the sake of brevity, the connecting member 23 shown is not described in detail here.

[0224] The embodiment of the present application further provides a battery, which includes at least one battery cell 30 of the embodiment of the present application.

[0225] An embodiment of the present application further provides an electrical device, comprising the battery of the above embodiment, wherein the battery is used to provide electrical energy to the electrical device.

[0226] The electrical device can be Figure 1 The vehicle shown may also be any device using a battery.

[0227] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: A housing, the housing having a first wall, the first wall being provided with a pressure relief mechanism; an electrode assembly, contained in the housing; A support structure is disposed between the electrode assembly and the first wall and fixedly connected to the first wall, and the support structure is used to form an exhaust channel between the first wall and the electrode assembly that is connected to the pressure relief mechanism.

2. The battery cell according to claim 1, characterized in that: The supporting structure is used to support the electrode assembly.

3. The battery cell according to claim 1 or 2, characterized in that: The melting point of the support structure is greater than 100°C.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The battery cell further comprises: an insulating member disposed between the electrode assembly and the first wall; Wherein, the insulating component is provided with an avoidance cavity, and the avoidance cavity is used to accommodate the supporting structure.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The battery cell further includes an insulating member for insulating the first wall from the electrode assembly, and the melting point of the supporting structure is higher than the melting point of the insulating member.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The supporting structure is fixedly connected to the first wall by welding.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The support structure and the first wall are integrally formed.

8. The battery cell according to any one of claims 1 to 7, characterized in that: An insulating layer is provided on a surface of the support structure facing the electrode assembly.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The material of the support structure is the same as that of the first wall.

10. The battery cell according to any one of claims 1 to 9, characterized in that: In a first direction, there is a gap between the housing and the electrode assembly; The support structure is provided with a cavity penetrating along the first direction, the cavity is used to connect the pressure relief mechanism and the gap, and the first direction is perpendicular to the thickness direction of the first wall.

11. The battery cell according to claim 10, characterized in that: The supporting structure comprises a first connecting wall and at least one supporting wall connected to each other, wherein the first connecting wall is fixedly connected to the first wall, and the supporting wall is perpendicular to the first connecting wall.

12. The battery cell according to claim 11, characterized in that: The at least one supporting wall includes two supporting walls arranged opposite to each other along a second direction, the second direction is perpendicular to a thickness direction of the first wall, and the second direction is perpendicular to the first direction.

13. The battery cell according to claim 12, characterized in that: The two supporting walls are respectively connected to the two ends of the first connecting wall along the second direction, and the supporting wall includes a first part perpendicular to the second direction and a second part parallel to the first connecting wall, the first part is connected to the first connecting wall, and the two second parts of the two supporting walls are spaced apart along the second direction.

14. The battery cell according to claim 13, characterized in that: In a thickness direction of the first wall, a projection of the second portion on the first wall is located within a projection of the first connecting wall on the first wall.

15. The battery cell according to claim 13, characterized in that: In a thickness direction of the first wall, a projection of the second portion on the first wall is located outside a projection of the first connecting wall on the first wall.

16. The battery cell according to claim 12, characterized in that: The support structure further includes a second connecting wall, which is arranged opposite to the first connecting wall along the thickness direction of the first wall. The first connecting wall, the second connecting wall and the two supporting walls are connected end to end to form the cavity.

17. The battery cell according to any one of claims 1 to 16, characterized in that: The support structure is disposed at an end region of the battery cell along a first direction.

18. The battery cell according to claim 17, characterized in that: In the first direction, the pressure relief mechanism is disposed between the two support structures, and the first direction is perpendicular to the thickness direction of the first wall.

19. The battery cell according to claim 17 or 18, characterized in that: The supporting structure is disposed in a middle region of the end region in a second direction, the second direction is perpendicular to a thickness direction of the first wall, and the second direction is perpendicular to the first direction.

20. The battery cell according to claim 17 or 18, characterized in that: The supporting structure is disposed at an edge region of the end region in a second direction, the second direction being perpendicular to a thickness direction of the first wall, and the second direction being perpendicular to the first direction.

21. The battery cell according to any one of claims 1 to 20, characterized in that: In the thickness direction of the first wall, a dimension h of the support structure and a dimension c of the battery cell satisfy: 0.003≤h / c≤0.

13.

22. The battery cell according to any one of claims 1 to 21, characterized in that: At least one of the support structures is disposed between the first wall and the electrode assembly. In the thickness direction of the first wall, the at least one support structure satisfies the following relationship between a total projected area S1 of the first wall and an area S of the first wall: 0.012≤S1 / S≤0.

26.

23. The battery cell according to any one of claims 1 to 22, characterized in that: The first wall is an end cap.

24. The battery cell according to any one of claims 1 to 23, characterized in that: The battery cell further comprises: An electrode terminal, disposed on the first wall; The electrode terminal is electrically connected to the electrode assembly.

25. A battery, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 24.

26. An electrical device, characterized in that: The battery as claimed in claim 25 is used to provide electrical energy to the electrical device.

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