Battery cell, battery, and electric device

Abstract

Embodiments of the present application provide a battery cell, a battery, and an electric device. The battery cell comprises: a casing having a first wall, the first wall being provided with a pressure relief mechanism; an electrode assembly accommodated in the casing; and a support structure arranged between the casing and the electrode assembly, wherein the support structure is used for forming between the first wall and the electrode assembly an exhaust channel communicated with the pressure relief mechanism. According to the battery cell, the battery and the electric device in the embodiments of the present application, the possibility of non-directional pressure relief of the battery cell can be reduced.

Description

Battery cells, batteries and electrical devices

[0001] This application claims priority to the invention application filed with the Patent Office of China on August 16, 2023, with application number 202311034049.4 and invention name “Battery Cell, Battery and Electrical Device”, all contents of which are incorporated into this application by application. Technical Field

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

[0003] In the related art, when a battery cell experiences thermal runaway, the electrode assembly is at risk of moving toward the first wall of the outer shell provided with a pressure relief mechanism, causing it to come into contact with the first wall, thereby blocking the directional pressure relief channel between the first wall and the electrode assembly, causing non-directional pressure relief in the battery cell.

[0004] Summary of the Invention

[0005] In view of this, embodiments of the present application provide a battery cell, a battery, and an electrical device, which can reduce the probability of non-directional pressure release in the battery cell.

[0006] In a first aspect, a battery cell is provided, comprising: a shell having a first wall, the first wall being provided with a pressure relief mechanism; an electrode assembly accommodated in the shell; and a support structure arranged between the shell and the electrode assembly, 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.

[0007] In this embodiment, the support structure is used to form an exhaust channel connected to the pressure relief mechanism between the first wall and the electrode assembly, so that in the event of thermal runaway of the battery cell, the exhaust channel can guide the thermal runaway gas to the pressure relief mechanism, and then the thermal runaway gas can be discharged from the pressure relief mechanism to the outside of the battery cell in a timely manner, thereby reducing the possibility of non-directional pressure relief of the battery cell.

[0008] In one possible implementation, the support structure is used to support the electrode assembly.

[0009] In this embodiment, the support structure is used to support the electrode assembly, which is conducive to 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.

[0010] In a possible implementation, the melting point of the support structure is greater than 100°C.

[0011] 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 forming 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.

[0012] In one possible implementation, the support structure includes a first support member disposed between the first wall and the electrode assembly.

[0013] In this embodiment, by arranging a first support member between the first wall and the electrode assembly, the electrode assembly can be directly limited. When thermal runaway occurs in the battery cell, the electrode assembly can be prevented from moving toward the first wall, so that the thermal runaway gas can reach the pressure relief mechanism through the exhaust channel formed between the first wall and the electrode assembly, and then can be discharged from the pressure relief mechanism to the battery cell in a timely manner, reducing the possibility of non-directional pressure relief in the battery cell.

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

[0015] In this embodiment, by fixedly connecting the first support member to the first wall and arranging the first support member between the first wall and the electrode assembly, movement of the first support member within the battery cell can be reduced, thereby reducing the probability of the first support member blocking the pressure relief mechanism.

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

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

[0018] In a possible implementation, the battery cell further includes: a first insulating member disposed between the electrode assembly and the first wall; wherein the first insulating member is provided with an escape cavity, and the escape cavity is used to accommodate the first support member.

[0019] In this embodiment, by providing an avoidance cavity on the first insulating member to accommodate the first support member, it is possible to increase the energy density of the battery cell without occupying additional space of the battery cell in the thickness direction of the first wall without affecting the insulation between the first wall and the electrode assembly.

[0020] In a possible implementation, the battery cell further includes a first insulating member, the first insulating member is used to insulate the first wall and the electrode assembly, and the melting point of the first support is higher than that of the first insulating member.

[0021] In this embodiment, by setting the melting point of the first support member to be higher than the melting point of the first insulating member, the first support member 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.

[0022] In a possible implementation, in the thickness direction of the first wall, a projection of the first support member on the first wall is disposed at an end region of the first wall along a first direction, where the first direction is perpendicular to the thickness direction of the first wall.

[0023] In this embodiment, in the thickness direction of the first wall, the projection of the first support member on the first wall is arranged in the end area of ​​the first wall in the first direction, which can minimize the possibility of the end of the first wall 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.

[0024] In a possible implementation, in a first direction, there is a gap between the electrode assembly and the housing, and the first support member is provided with a first cavity penetrating along the first direction, and the first cavity is used to connect the gap and the pressure relief mechanism.

[0025] In this embodiment, the first support member is provided with a first cavity extending along a 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 have time to be exhausted and the shell will be broken.

[0026] In a possible implementation manner, the first support member is provided with at least one first through hole extending through the first direction, and the first cavity includes the at least one first through hole.

[0027] In this embodiment, by providing at least one first through hole extending through the first direction in the first support member to form a first cavity, on the one hand, the possibility of the thermal runaway gas accumulated in the gap not being able to be exhausted in time and causing the shell to be broken can be reduced; on the other hand, the weight of the battery cell can also be reduced and the energy density of the battery cell can be improved.

[0028] In one possible implementation, the first support member includes a plurality of first support blocks spaced apart in a second direction, the first cavity includes the spacing between every two adjacent first support blocks in the plurality of first support blocks, the second direction is perpendicular to the thickness direction of the first wall, and the second direction is perpendicular to the first direction.

[0029] In this embodiment, a plurality of first support blocks are spaced apart in the second direction to form a first cavity. On the one hand, this can reduce the possibility that the thermal runaway gas accumulated in the gap will not be exhausted in time and the shell will be broken; on the other hand, it can also reduce the weight of the battery cell and improve the energy density of the battery cell.

[0030] In a possible implementation, in the thickness direction of the first wall, a dimension h of the first support member and a dimension c of the battery cell satisfy the following relationship: 0.003≤h / c≤0.13.

[0031] In this embodiment, if h / c is less than 0.003, it is very easy for particulate matter or electrode blockage to be generated due to internal loss of control of 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.

[0032] In one possible implementation, at least one first support member is provided between the first wall and the electrode assembly, and in the thickness direction of the first wall, the total projected area S1 of the at least one first support member on the first wall and the area S of the first wall satisfy: 0.012≤S1 / S≤0.26.

[0033] In this embodiment, when S1 / S is less than 0.012, the contact area between the first support member and the first wall is too small when thermal runaway occurs in the battery cell. This, on the one hand, fails to provide sufficient mechanical support for the electrode assembly, potentially causing the internal electrode assembly to wobble or overlap with the first wall, and even further deteriorating the exhaust path. When S1 / S is greater than 0.26, on the one hand, the weight of the battery cell increases, sacrificing energy density, and on the other hand, the free space inside the battery cell occupied by the first support member is further reduced, hindering directional pressure relief. Setting S1 / S between 0.012 and 0.26 achieves the goal of balancing the energy density of the battery cells and forming an exhaust channel between the first wall and the electrode assembly.

[0034] In a possible implementation, the housing further includes a second wall intersecting with the first wall, and the support structure includes a second support member fixedly connected to the second wall.

[0035] In this embodiment, a second support member is fixedly provided on the second wall of the outer shell intersecting with the first wall to support the electrode assembly. This helps prevent the end of the electrode assembly from moving toward the first wall when thermal runaway occurs in the battery cell, thereby increasing the probability of forming an exhaust channel between the first wall and the electrode assembly when thermal runaway occurs in the battery cell.

[0036] In a possible implementation, the second wall forms an accommodation space with an opening, the first wall covers the opening to dispose the electrode assembly in the accommodation space, and the second support member is disposed at the opening.

[0037] In this embodiment, by arranging the second support member at the opening of the accommodating space formed by the second wall, the possibility of blocking the end of the electrode assembly from moving toward the first wall can be increased, thereby increasing the probability of forming an exhaust channel between the first wall and the electrode assembly when thermal runaway occurs in the battery cell.

[0038] In a possible implementation, the second support member is provided with a second cavity penetrating along the thickness direction of the first wall, and the second cavity is used to guide the thermal runaway gas accumulated between the second wall and the electrode assembly to the exhaust channel.

[0039] In this embodiment, by providing a second cavity penetrating along the thickness direction of the first wall in the second support member, the electrode assembly can be supported by the second support member to reduce the possibility of the end of the electrode assembly moving toward the first wall, and the thermal runaway gas accumulated between the second wall and the electrode assembly 32 can be guided to the exhaust channel through the second cavity, thereby reducing the possibility of non-directional pressure release of the battery cell.

[0040] In a possible implementation, the second support member includes a plurality of second support blocks spaced apart along the circumference of the opening, and the second cavity includes a space between every two second support blocks in the plurality of second support blocks.

[0041] In this embodiment, a plurality of second support blocks are spaced apart along the circumference of the opening to form a second cavity, which can reduce the possibility that the thermal runaway gas accumulated between the second wall and the electrode assembly will not be exhausted in time and may cause the shell to be broken.

[0042] In one possible implementation, in the thickness direction of the first wall, the surface of the second support member away from the first wall is closer to the first wall than the surface of the electrode assembly close to the first wall; in the thickness direction of the first wall, the projection of the second support member on the first wall and the projection of the electrode assembly on the first wall have an intersection.

[0043] In this embodiment, in the thickness direction of the first wall, the projection of the second support member on the first wall and the projection of the electrode assembly on the first wall have an intersection, and the second support member is closer to the first wall than the electrode assembly, so that when thermal runaway occurs in the battery cell, the second support member can block the electrode assembly from approaching the first wall, thereby forming an exhaust channel between the first wall and the electrode assembly, reducing the possibility of non-directional pressure release in the battery cell.

[0044] In one possible implementation, the battery cell further includes: an insulating assembly, disposed between the outer shell and the electrode assembly, for insulating the outer shell and the electrode assembly; the support structure includes a third support member, the third support member is fixedly connected to the insulating assembly, and the third support member is disposed between the outer shell and the insulating assembly.

[0045] In this embodiment, a third support member is provided between the outer shell and the electrode assembly and the outer shell, and the third support member is fixedly connected to the insulating assembly to support the electrode assembly. This helps to reduce the possibility of the electrode assembly moving toward the first wall when thermal runaway occurs in the battery cell, thereby increasing the probability of forming an exhaust channel between the first wall and the electrode assembly.

[0046] In a possible implementation, the insulating assembly includes a first insulating member, the first insulating member is disposed between the first wall and the electrode assembly, and the third support is fixedly connected to the first insulating member.

[0047] In this embodiment, by arranging a first insulating member between the first wall and the electrode assembly and fixing the third support member to the first insulating member, the possibility of the electrode assembly moving toward the first wall can be reduced when thermal runaway occurs in the battery cell, thereby increasing the probability of forming an exhaust channel between the first wall and the electrode assembly.

[0048] In a possible implementation, the insulating assembly includes a second insulating member, the second insulating member is coated on the outer surface of the electrode assembly, and the third support is fixedly connected to the second insulating member.

[0049] In this embodiment, by fixing the third support member to the second insulating member covering the outer surface of the electrode assembly to support the electrode assembly, the possibility of the electrode assembly moving toward the first wall is reduced when thermal runaway occurs in the battery cell, thereby increasing the probability of forming an exhaust channel between the first wall and the electrode assembly.

[0050] In a possible implementation, the third support member is fixedly connected to the insulating assembly by snapping.

[0051] In this embodiment, the third support member and the insulating assembly are fixedly connected by snapping, which can improve the bonding strength between the third support member and the insulating assembly and reduce the probability of the third support member moving inside the battery cell to block the exhaust channel A.

[0052] In a possible implementation, the third support member is fixedly connected to the insulating assembly by bonding.

[0053] In this embodiment, the third support member and the insulating assembly can be fixedly connected by bonding, which can improve the bonding strength between the third support member and the insulating assembly and reduce the probability of the third support member moving inside the battery cell to block the exhaust channel.

[0054] In a possible implementation, the third support member has a second through hole, and the second through hole is used to release the thermal runaway gas generated by the electrode assembly to between the insulation assembly and the shell.

[0055] In this embodiment, by providing a second through hole in the third support member, the thermal runaway gas generated by the electrode assembly can be released in time between the insulating assembly and the outer shell, thereby further guiding the thermal runaway gas to the exhaust channel, so that the thermal runaway gas can be discharged through the pressure relief mechanism.

[0056] In a possible implementation manner, the third support member is provided with a groove opening toward the housing.

[0057] In this embodiment, by providing a groove with an opening toward the housing on the third support member, on the one hand, the accommodation space for thermal runaway gas can be increased, and on the other hand, the weight of the battery cell can be reduced and the energy density of the battery cell can be improved.

[0058] In one possible implementation, the battery cell also includes: a support plate, arranged between the electrode assembly and the shell, and located below the electrode assembly along the direction of gravity; the support structure includes a fourth support member, arranged below the electrode assembly along the direction of gravity, and the melting point of the fourth support member is higher than the melting point of the support plate.

[0059] In this embodiment, a fourth support member is provided on a side where a support plate is provided to support the electrode assembly, and the melting point of the fourth support member is higher than that of the support plate. This is advantageous in that in the event of thermal runaway of the battery cell, even if the support plate is melted, the fourth support member is not easily melted and can still play the role of supporting the electrode assembly, and a space is formed to accommodate thermal runaway gas, thereby reducing the possibility of non-directional pressure release of the battery cell.

[0060] In a possible implementation manner, the fourth support member is fixedly connected to the support plate.

[0061] In this embodiment, by fixedly connecting the fourth support member to the support plate, a space for accommodating thermal runaway gas is formed between the electrode assembly and the support plate, thereby reducing the possibility of non-directional pressure release of the battery cell.

[0062] In a possible implementation, the first wall is an end cover.

[0063] In this embodiment, the first support member is fixed to the end cover. Compared with fixing the first support member to other walls of the shell, the first support member and the end cover can be fixed together externally, or the first support member can be directly formed when preparing the end cover, without extending the first support member into the shell for fixing, thereby improving the preparation efficiency of the battery cell.

[0064] In a possible implementation, the battery cell further includes: an electrode terminal disposed on the first wall; the electrode terminal is electrically connected to the electrode assembly.

[0065] In this embodiment, electrical connection between the electrode terminal provided on the first wall and the electrode assembly can be achieved to realize electrical connection with other battery cells, thereby achieving the purpose of expanding the battery capacity.

[0066] In a second aspect, a battery is provided, comprising the battery cell according to the first aspect and any possible implementation of the first aspect.

[0067] In a third aspect, an electrical device is provided, comprising the battery according to the second aspect, wherein the battery is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. 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 creative work.

[0069] FIG1 is a schematic structural diagram of a vehicle disclosed in an embodiment of the present application.

[0070] FIG2 is a schematic structural diagram of a battery disclosed in an embodiment of the present application.

[0071] FIG3 is an exploded schematic diagram of a battery cell disclosed in an embodiment of the present application.

[0072] FIG4 is a planar cross-sectional view of a battery cell disclosed in an embodiment of the present application.

[0073] FIG5 is an exploded schematic diagram of a battery cell disclosed in another embodiment of the present application.

[0074] FIG. 6 shows a partial cross-sectional view of the battery cell in FIG. 5 along the YZ plane.

[0075] FIG7 shows a schematic diagram of the connection between the first wall and the first support member disclosed in an embodiment of the present application.

[0076] FIG8 shows a schematic diagram of the connection between the first insulating member and the first supporting member disclosed in an embodiment of the present application.

[0077] FIG9 shows another planar cross-sectional view of a battery cell disclosed in an embodiment of the present application.

[0078] FIG10 shows a top view of a first wall disclosed in an embodiment of the present application.

[0079] FIG11 shows an exploded schematic diagram of another battery cell disclosed in an embodiment of the present application.

[0080] FIG12 shows a cross-sectional view of the housing in FIG9 along the XZ plane.

[0081] FIG13 shows a cross-sectional view of the battery cell in FIG9 along the YZ plane.

[0082] FIG14 shows an exploded schematic diagram of another battery cell disclosed in an embodiment of the present application.

[0083] FIG15 shows an exploded schematic diagram of another battery cell disclosed in an embodiment of the present application.

[0084] FIG16 shows a schematic diagram of a first connection between the third support member and the second insulating member disclosed in an embodiment of the present application.

[0085] FIG17 shows a schematic diagram of a second connection between the third support member and the second insulating component disclosed in an embodiment of the present application.

[0086] FIG18 shows a schematic structural diagram of a second insulating component disclosed in an embodiment of the present application.

[0087] FIG19 shows another structural schematic diagram of the second insulating component disclosed in an embodiment of the present application.

[0088] FIG20 shows another planar cross-sectional view of a battery cell disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0089] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0090] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art 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" and "second" 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-secondary relationship.

[0091] 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.

[0092] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0093] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0094] The term "multiple" in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0095] 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.

[0096] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0097] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0098] In some embodiments, the positive electrode may be a positive electrode sheet, which 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.

[0099] 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 provided on either or both of the two facing surfaces of the positive electrode current collector.

[0100] 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 with a silver surface treatment, 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 layer 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.).

[0101] 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. 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.

[0102] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0103] 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 with a silver surface treatment, 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 layer 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.).

[0104] 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.

[0105] 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 provided on either or both of the two facing surfaces of the negative electrode current collector.

[0106] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. 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, and lithium titanate.

[0107] In some embodiments, the negative electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. When the metal foam is used as the negative electrode, the surface of the metal foam may or may not be provided with a negative electrode active material.

[0108] As an example, the negative electrode current collector may 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.

[0109] 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.

[0110] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0111] 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 and mechanical stability can be selected.

[0112] 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.

[0113] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0114] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0115] 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.

[0116] In some embodiments, the electrode assembly is a laminate structure.

[0117] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0118] As an example, multiple positive electrode sheets may be provided, and the negative electrode sheet is folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0119] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0120] As an example, multiple separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0121] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0122] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0123] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0124] In some embodiments, a battery cell may include an outer casing. The outer casing is used to encapsulate components such as the electrode assembly and electrolyte. The outer casing 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. The outer casing includes a housing and end caps.

[0125] 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, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0126] 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 hybrid through a busbar.

[0127] 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.

[0128] 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 housed in the case.

[0129] 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.

[0130] At present, when a battery cell experiences internal or external short circuit due to mechanical external force or other reasons, it may cause thermal runaway of the battery cell. A large amount of thermal runaway gas will be generated inside the battery cell 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 realizing directional pressure relief.

[0131] 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 the thermal runaway process. For example, the exhaust channel in the battery cell that reaches the pressure relief mechanism is blocked, causing damage to the shell and gas pressure relief from the damaged area. This phenomenon will cause secondary disasters of verification at the system level, such as impacting adjacent battery cells to cause heat diffusion, impacting high-voltage wiring harnesses to cause high-voltage sparks, etc.

[0132] In view of this, an embodiment of the present application provides a battery cell, in which a support structure is arranged between the outer shell and the electrode assembly, and the support structure is used to support the electrode assembly, so as to form an exhaust channel between the first wall of the outer shell provided with a pressure relief mechanism and the electrode assembly to guide the thermal runaway gas to the pressure relief mechanism, 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 reducing the possibility of non-directional pressure relief in the battery cell.

[0133] The technical solutions described in the embodiments of the present application are applicable to various battery-powered devices, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, electric vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0134] 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 explained using electric vehicles as an example.

[0135] For example, as shown in FIG1 , 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 provided 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 provided at the bottom, front or rear of the vehicle 1. The battery 100 may be used to power 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.

[0136] For example, as shown in FIG2 , it is a schematic structural diagram 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 case, the interior of which is a hollow structure, and a plurality of battery cells 20 may be accommodated in the case. As shown in FIG2 , the case may include two parts, which are respectively referred to as a first case portion 111 and a second case portion 112, and the first case portion 111 and the second case portion 112 are snapped together. The shapes of the first case portion 111 and the second case portion 112 may be determined according to the shape of the combination of the plurality of battery cells 20, and at least one of the first case portion 111 and the second case portion 112 has an opening. For example, as shown in FIG2 , only one of the first case portion 111 and the second case portion 112 is a hollow cuboid with an opening, and the other is plate-shaped to cover the opening. Here, for example, the second housing portion 112 is a hollow rectangular parallelepiped with only one open face, and the first housing portion 111 is plate-shaped. The first housing portion 111 covers the opening of the second housing portion 112 to form the housing 11 with a closed chamber. This chamber can be used to accommodate multiple battery cells 20. The multiple battery cells 20 are connected in parallel, series, or in a mixed combination and then placed in the housing formed by the first housing portion 111 and the second housing portion 112 being fastened together.

[0137] For another example, unlike that shown in FIG2 , the first and second housing portions 111, 112 can each be a hollow cuboid with only one open face. The opening of the first and second housing portions 111, 112 are positioned opposite each other, and the first and second housing portions 111, 112 are engaged with each other to form a housing having a closed chamber. Multiple battery cells 20 are connected in parallel, series, or in a mixed series arrangement and then placed within the housing formed by the engagement of the first and second housing portions 111, 112.

[0138] In some embodiments, the battery 100 may further include other structures, which will not be described in detail here. For example, the battery 100 may further include a busbar component (not shown in the figure), which is used to realize the electrical connection between the 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 the multiple battery cells 20 can be further led out through the box through a conductive mechanism. In some embodiments, the conductive mechanism may also belong to the busbar component.

[0139] 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 a hybrid connection, where hybrid connection refers to a mixture of series and parallel connections. The battery 100 can also be referred to as a battery pack. In some embodiments, multiple battery cells can first be connected in series, in parallel, or in a hybrid connection to form a battery module, and multiple battery modules can then be connected in series, in parallel, or in a hybrid connection to form the battery 100. In other words, multiple battery cells can directly form the battery 100, or they can first form a battery module, and then the battery modules can form the battery 100.

[0140] FIG3 shows a schematic exploded view of a battery cell 20 according to an embodiment of the present application.

[0141] As shown in FIG3 , a battery cell 20 includes one or more electrode assemblies 22, a housing 211, and an end cap 212. The walls of the housing 211 and the end cap 212 are collectively referred to as the walls of the battery cell 20. The housing 211 is shaped according to the shape of the one or more electrode assemblies 22 after assembly. For example, the housing 211 may be a hollow rectangular parallelepiped, a cube, or a cylinder, with one of its faces having an opening to allow the one or more electrode assemblies 22 to be placed within the housing 211. For example, when the housing 211 is a hollow rectangular parallelepiped or a cube, one of the planes of the housing 211 is an open face, i.e., the plane has no walls, allowing the inside and outside of the housing 211 to communicate. When the housing 211 is a hollow cylinder, the end faces of the housing 211 are open faces, i.e., the end faces have no walls, allowing the inside and outside of the housing 211 to communicate. The end cap 212 covers the opening and is connected to the housing 211 to form a closed cavity for placing the electrode assemblies 22. The housing 211 is filled with an electrolyte, such as an electrolyte solution.

[0142] The battery cell 20 also includes two electrode terminals 214. The end cap 212 is typically a flat plate, and the two electrode terminals 214 are fixed to the flat surface of the end cap 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 connecting member 23, also known as a current collecting member, which is located between the end cap 212 and the electrode assembly 22 and is used to electrically connect the electrode assembly 22 and the electrode terminal 214.

[0143] As shown in FIG3 , each electrode assembly 22 has a first electrode tab 221a and a second electrode tab 222a. The first electrode tab 221a and the second electrode tab 222a have opposite polarities. For example, when the first electrode tab 221a is a positive electrode tab, the second electrode tab 222a is a negative electrode tab. The first electrode tab 221a of one or more electrode assemblies 22 is connected to one electrode terminal 214 via a connecting member 23, and the second electrode tab 222a of one or more electrode assemblies 22 is connected to another electrode terminal 214 via another connecting member 23. For example, the first electrode tab 221a is a positive electrode tab and the second electrode tab 222a is a negative electrode tab. The positive electrode terminal 214a is connected to the first electrode tab 221a via a connecting member 23, and the negative electrode terminal 214b is connected to the second electrode tab 222a via another connecting member 23.

[0144] In the battery cell 20 , the electrode assembly 22 can be provided as a single one or multiple ones according to actual use requirements. As shown in FIG3 , four independent electrode assemblies 22 are provided in the battery cell 20 .

[0145] 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 configured to be activated to release the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a threshold.

[0146] Optionally, the pressure relief mechanism 213 may be provided on the end cover 212 or on any wall of the housing 211 .

[0147] FIG4 shows a planar cross-sectional view of a battery cell 30 according to an embodiment of the present application.

[0148] As shown in Figure 4, the battery cell 30 includes: a shell 31, having a first wall 311, on which a pressure relief mechanism 312 is provided; an electrode assembly 32, accommodated in the shell 31; a support structure 33, arranged between the shell 31 and the electrode assembly 32, and 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.

[0149] It should be explained that the housing 31 may include the shell 211 and the end cover 212 shown in FIG3 , and the first wall 311 may be any wall of the shell 211 or the end cover 212 . In other words, the pressure relief mechanism 213 may be provided on any wall of the battery cell 30 .

[0150] 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 existence of 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.

[0151] In this embodiment, 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. In the event of thermal runaway of the battery cell 30, the exhaust channel A can guide the thermal runaway gas to the pressure relief mechanism 312, and then the thermal runaway gas can be discharged from the pressure relief mechanism 312 to the outside of the battery cell 30 in a timely manner, thereby reducing the possibility of non-directional pressure relief of the battery cell 30.

[0152] In some embodiments, the support structure 33 is used to support the electrode assembly 32 .

[0153] In other words, the support structure 33 may restrict the electrode assembly 32 from moving toward the first wall 311 .

[0154] For example, the support structure 33 is used to support the electrode assembly 32 when the battery cell 30 experiences thermal runaway. For another example, the support structure 33 can support the electrode assembly 32 regardless of whether the battery cell 30 experiences thermal runaway. This embodiment of the application is not limited to this.

[0155] 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 in the battery cell 30.

[0156] In other embodiments, the melting point of the support structure 33 is greater than 100°C.

[0157] In one example, the material of the support structure 33 may be a single material, for example, the material of the support structure 33 may be a single material such as aluminum or copper. In this case, the support structure 33 has a fixed melting point.

[0158] In another example, the material of the support structure 33 can be a composite material. For example, the support structure 33 can be a mixed material of aluminum and copper. In this case, the first support member 331 does not have a fixed melting point, that is, the melting point of the support structure 33 is a melting point range of various materials. For example, the melting point of aluminum 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. 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.

[0159] For example, if 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, allowing the thermal runaway gas to reach the pressure relief mechanism 312 smoothly before the pressure relief mechanism 312 opens. Furthermore, optionally, the melting point of the support structure 33 can be greater than 500°C, allowing the battery cell 30 to maintain mechanical strength during thermal runaway. The compound with an olivine structure can be selected from lithium iron phosphate, lithium manganese iron phosphate, or a mixture of lithium iron phosphate and lithium manganese iron phosphate.

[0160] For another example, if the positive electrode material of the battery cell contains 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, which can enable the battery cell 30 to maintain mechanical strength during the thermal runaway process. Among them, the layered compound can be selected from lithium nickel cobalt manganese oxygen ternary layered material, or a mixture of lithium iron phosphate and lithium nickel cobalt manganese oxygen ternary layered material, or a mixture of lithium manganese iron and lithium nickel cobalt manganese oxygen ternary layered material.

[0161] Optionally, the material of the support structure 33 can be a high-temperature resistant material. For example, the material of the support structure 33 can include at least one of metal, graphite, polytetrafluoroethylene, mica, or ceramic. In some embodiments, the support structure 33 itself can be directly made of a material with insulating properties such as polytetrafluoroethylene, mica, or ceramic. In other embodiments, the support structure 33 itself can be made of a metal material with an insulating layer provided on its outer surface.

[0162] 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 forming 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.

[0163] It should be understood that the embodiment of the present application does not limit the positional relationship between the support structure 33 and the wall of the housing 31. For example, the support structure 33 is set between the first wall 311 and the electrode assembly 32 to directly restrict the movement of the electrode assembly 32 toward the first wall 311. For another example, the support structure 33 is set between the side walls intersecting with the first wall 311 to indirectly restrict the movement of the electrode assembly 32 toward the first wall 311 through the friction between the support structure 33 and the electrode assembly 32. It should also be understood that the embodiment of the present application does not limit the components fixedly connected to the support structure 33. For example, the support structure 33 can be directly fixed on the first wall 311. For another example, the support structure 33 can be fixedly connected to the second wall intersecting with the first wall. For another example, the support structure 33 can also be fixedly connected to the insulating assembly, and the embodiment of the present application does not impose any limitation on this.

[0164] Figures 5 to 7, 9, and 10 illustrate various schematic diagrams of an embodiment in which the support structure 33 is fixedly connected to the first wall 311. Figures 11 to 13 illustrate various schematic diagrams of an embodiment in which the support structure 33 is fixedly connected to the second wall 313 of the housing 31. Figures 8 and 14 to 19 illustrate various schematic diagrams of an embodiment in which the support structure 33 is fixedly connected to the insulating assembly 40. Figure 20 illustrates an embodiment in which the support structure 33 is fixedly connected to the support plate 41.

[0165] Figures 5 to 10 and 14 illustrate various schematic diagrams of an embodiment in which the support structure 33 is disposed between the first wall 311 and the electrode assembly 32, distinguished by the positional relationship between the support structure 33 and the walls of the housing 31. Figures 11 to 13, 15, 18, and 19 illustrate various schematic diagrams of an embodiment in which the support structure 33 is disposed between the second wall 313 and the electrode assembly 32. Figure 20 illustrates an embodiment in which the support structure is disposed between a third wall 315 of the housing 31, which is located opposite the first wall 311, and the electrode assembly 32.

[0166] Optionally, as shown in FIG. 5 to FIG. 10 and FIG. 14 , the support structure 33 includes a first support member 331 disposed between the first wall 311 and the electrode assembly 32 .

[0167] In this embodiment, by arranging a first support member 331 between the first wall 311 and the electrode assembly 32, the electrode assembly 32 can be directly limited. When thermal runaway occurs in the battery cell 30, the electrode assembly 32 can be prevented from moving toward the first wall 311, so that the thermal runaway gas can reach the pressure relief mechanism 312 through the exhaust channel A formed between the first wall 311 and the electrode assembly 32, and then can be discharged from the pressure relief mechanism 312 to the battery cell 30 in a timely manner, reducing the possibility of non-directional pressure relief in the battery cell 30.

[0168] In one embodiment, as shown in FIG5 , the first support member 331 is fixedly connected to the first wall 311 , that is, the first support member 331 is fixed to the surface of the first wall 311 facing the electrode assembly 32 .

[0169] In an example, the material of the first support member 331 includes a metal material, and the first support member 331 and the first wall 311 can be fixedly connected by welding.

[0170] In another example, the material of the first support member 331 includes a hard material such as a non-metal, and the first support member 331 and the first wall 311 can be fixedly connected by bonding or other methods.

[0171] In this embodiment, by fixedly connecting the first support member 331 to the first wall 311 and positioning the first support member 331 between the first wall 311 and the electrode assembly 32, the first support member 331 can be reduced in movement within the battery cell 30, thereby reducing the probability of the first support member 331 blocking the pressure relief mechanism 312. Furthermore, an exhaust channel A communicating with the pressure relief mechanism 312 can be formed between the first wall 311 and the electrode assembly 32, thereby reducing the possibility of non-directional pressure relief within the battery cell 30.

[0172] In another embodiment, the first support member 331 may be integrally formed with the first wall 311 .

[0173] In this embodiment, the first support member 331 and the first wall 311 are integrally formed, which can improve the bonding strength between the first wall 311 and the first support member 331, further reduce the movement of the first support member 331 in the battery cell 30, and reduce the probability of the first support member 331 blocking the pressure relief mechanism 312.

[0174] In some examples, the first wall 311 may be an end cap.

[0175] In this embodiment, the first support member 331 is fixed to the end cover. Compared with fixing the first support member 331 to other walls of the shell, the first support member 331 can be fixed to the end cover externally, or the first support member 331 can be directly formed when preparing the end cover, without extending the first support member 331 into the shell 31 for fixing, thereby improving the preparation efficiency of the battery cell 30.

[0176] 5 , as shown in FIG5 , the battery cell 30 further includes a first insulating member 34 disposed between the electrode assembly 32 and the first wall 311 ; wherein the first insulating member 34 is provided with an escape cavity 341 for accommodating the first support member 331 .

[0177] Typically, the first insulating member 34 is disposed between the first wall 311 and the electrode assembly 32 to insulate the first wall 311 from the electrode assembly 32, thereby achieving electrical isolation between the first wall 311 and the electrode assembly 32. Optionally, the material of the first insulating member 34 may include at least one material such as polypropylene (PP), polyphenylene sulfide (PPS), or soluble polytetrafluoroethylene (PFA).

[0178] Optionally, the first insulating member 34 may be provided with an escape cavity 341 opening toward the first wall 311 , so that the first support 331 fixed to the surface of the first wall 311 facing the electrode assembly 32 may be accommodated in the escape cavity 341 .

[0179] In this embodiment, by providing an avoidance cavity 341 on the first insulating member 34 to accommodate the first support member 331, 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.

[0180] In other embodiments, the first support member 331 may be fixedly connected to the first wall 311 , or the first support member 331 may be fixed in the avoidance cavity 341 .

[0181] Optionally, the melting point of the first support 331 is higher than the melting point of the first insulating member 34 .

[0182] Typically, in the later stages of thermal runaway, the first insulating member 34 may melt, causing 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 for the thermal runaway gas to reach the pressure relief mechanism 312. In this embodiment, by setting the melting point of the first support member 331 to be higher than the melting point of the first insulating member 34, the first support member 331 is less likely to melt in the later stages of thermal runaway, providing 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 in the battery cell 30.

[0183] In other embodiments, the first support member 331 is disposed between the first wall 311 and the electrode assembly 32 , and the first support member 331 is fixed to the first insulating member 34 .

[0184] For example, as shown in FIG8 , the first insulating member 34 may be provided with a relief cavity 341 opening toward the electrode assembly 32, and the first support member 331 may be fixed within the relief cavity 341 by interference fit. Alternatively, regardless of whether the relief cavity 341 opens toward the first wall 311 or the electrode assembly 32, the first support member 331 may be fixed within the relief cavity 341 by bonding.

[0185] In some examples, the first support member 331 may be in contact with the first wall 311. In other examples, a gap may exist between the first support member 331 and the first wall 311.

[0186] In this embodiment, by fixing the first support member 331 in the avoidance cavity 341 of the first insulating component 34, on the one hand, the movement of the first support member 331 in the battery cell 30 can be reduced, thereby reducing the probability of the first support member 331 blocking the pressure relief mechanism 312; on the other hand, there is no need to occupy additional space of the battery cell 30 in the thickness direction Z of the first wall 311, thereby improving the energy density of the battery cell 30.

[0187] Optionally, as shown in Figures 5 and 7 to 10, in the thickness direction Z of the first wall 311, the projection of the first support member 331 on the first wall 311 is arranged in the end area of ​​the first wall 311 along the first direction, and the first direction is perpendicular to the thickness direction Z of the first wall 311.

[0188] It should be noted that, in the embodiment of the present application, the first support member 331 is located in the end area of ​​the first wall 311 in the first direction compared to the pressure relief mechanism 312. For example, the battery cell 30 includes two first support members 331, and the projections of the two first support members 331 on the first wall 311 are respectively arranged at the two ends of the first wall 311 along the first direction, and the pressure relief mechanism 312 is arranged between the two first support members 331.

[0189] In this embodiment, in the thickness direction Z of the first wall 311, the projection of the first support member 331 on the first wall 311 is arranged in the end area of ​​the first wall 311 in the first direction, which can minimize the possibility of the end of the first wall 311 in the first direction abutting against the electrode assembly 32, so that the thermal runaway gas in the battery cell 30 can reach the pressure relief mechanism 312, thereby reducing the possibility of non-directional pressure relief of the battery cell 30.

[0190] In one example, the battery cell 30 is a square battery cell, and the first direction can be the length direction Z of the first wall 311 or the width direction of the first wall 311. Specifically, a first support member 331 can be provided at each end of the first wall 311 along the length direction X and / or along the width direction Y.

[0191] In another example, the battery cell 30 is a cylindrical battery cell, and the first direction is a radial direction of the first wall 311. Specifically, along the circumference of the first wall 311, the first support members 331 are distributed at intervals at the ends of the first wall 311.

[0192] Furthermore, as shown in Figures 5 to 7 and 9, in the first direction, there is a gap 36 between the electrode assembly 32 and the shell 31, and the first support member 331 is provided with a first cavity 35 that passes through along the first direction. The first cavity 35 is used to connect the gap 36 and the pressure relief mechanism 312.

[0193] In this embodiment, the first support member 331 is provided with a first cavity 35 extending 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 have time to be exhausted and cause the shell 31 to be broken.

[0194] In an example, as shown in FIG. 6 , the first support member 331 is provided with at least one first through hole 351 penetrating along the first direction, and the first cavity 35 includes the at least one first through hole 351 .

[0195] Optionally, the first support member 331 is provided with a plurality of first through holes 351. The plurality of first through holes 351 can be spaced apart along a second direction, where the second direction is perpendicular to both the thickness direction Z of the first wall 311 and the first direction. For example, the first direction is the length direction X of the first wall 311, and the second direction is the width direction Y of the first wall 311. For another example, the first direction is the width direction Y of the first wall 311, and the second direction is the length direction X of the first wall 311.

[0196] Optionally, the first support member 331 may also be provided with a large first through hole 351 to increase the ventilation area as much as possible, while also being able to reduce the weight of the battery cell 30 and improve the energy density of the battery cell 30 .

[0197] In this embodiment, by providing at least one first through hole 351 extending through the first direction in the first support member 331 to form a first cavity 35, on the one hand, the possibility of the thermal runaway gas accumulated in the gap 36 not being able to be exhausted in time and causing the shell 31 to be broken can be reduced; on the other hand, the weight of the battery cell 30 can also be reduced, and the energy density of the battery cell 30 can be improved.

[0198] In another example, as shown in Figure 7, the first support member 331 includes a plurality of first support blocks 3310 spaced apart in the second direction, and the first cavity 35 includes a gap 352 between every two adjacent first support blocks 3310 in the plurality of first support blocks 3310, wherein the second direction is perpendicular to both the thickness direction of the first wall 311 and the first direction.

[0199] In this embodiment, a plurality of first support blocks 3310 are spaced apart in the second direction to form a first cavity 35. On the one hand, this can reduce the possibility that the thermal runaway gas accumulated in the gap 36 will not have time to be exhausted and the outer shell 31 will be broken; on the other hand, it can also reduce the weight of the battery cell 30 and improve the energy density of the battery cell 30.

[0200] Optionally, as shown in FIG. 9 , in the thickness direction Z of the first wall 311 , the dimension h of the first support member 331 and the dimension c of the battery cell satisfy the following relationship: 0.003≦h / c≦0.13.

[0201] In this embodiment, if h / c is less than 0.003, it is very easy for the battery cell 30 to be blocked by particulate matter or electrode blocks due to internal loss of control, 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.

[0202] The technical effects achieved by 0.003≤h / c≤0.13 will be described in detail below with reference to specific embodiments.

[0203] Specifically, the battery cell shell measures 44mm*220mm*100mm (width*length*height), with an energy density of 250Wh / kg. An end cap (e.g., first wall) with a first support member is machined and manufactured. The end cap has a pressure relief mechanism. The first support members are two regular quadrangular prisms, symmetrically distributed and located at either end of the short side of the end cap. They are 41mm long and 0.5mm from the long side of the end cap, respectively. The distance from the first support member to the short side of the end cap is 7mm. First support members of varying heights are fabricated. The battery cell is then triggered to lose control using a built-in heating film, and the directional pressure relief of the battery cell is observed. The pressure relief mechanism's valve opening pressure is 1.0MPa, and the end cap weld strength is 1.5MPa. Simultaneously, air pipes are connected to the end cap and the side to detect the internal air pressure of the battery cell. The data is shown in Table 1.

[0204] Table 1

[0205] As can be seen from Table 1, 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 is severely lost; 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.

[0206] Further optionally, 0.03≤h / c≤0.08.

[0207] Optionally, as shown in Figure 10, a plurality of first support members 331 are arranged between the first wall 311 and the electrode assembly 32. In the thickness direction Z of the first wall 311, the plurality of first support members 331 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.

[0208] In this embodiment, when S1 / S is less than 0.012, the contact area between the first support member 331 and the first wall 311 is too small when thermal runaway occurs in the battery cell 30. This, on the one hand, fails to provide sufficient mechanical support for the electrode assembly 32, potentially causing the internal electrode assembly 32 to wobble or overlap with the first wall 311, and even further deteriorating the exhaust path. When S1 / S is greater than 0.26, on the one hand, the weight of the battery cell increases, sacrificing energy density, and on the other hand, the free space occupied by the first support member 331 within the battery cell 30 is further reduced, hindering directional pressure relief. Setting S1 / S between 0.012 and 0.26 achieves the goal 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.

[0209] The technical effects achieved by 0.012≤S1 / S≤0.26 will be described in detail below with reference to specific embodiments.

[0210] Specifically, the battery cell shell measures 44mm*220mm*100mm (width*length*height), with an energy density of 250Wh / kg. An end cap (e.g., first wall) with a first support member is machined and equipped with a pressure relief mechanism. The first support member consists of two regular quadrangular prisms, symmetrically distributed and located at either end of the short side of the end cap. The length and height are 41mm, 1mm, and width are used as a variable to control S1. The built-in heating film is then used to trigger the battery cell's runaway, and the directional pressure relief of the battery cell is observed. The pressure relief mechanism's valve opening pressure is 1.0MPa, and the end cap weld strength is 1.5MPa. Simultaneously, air pipes are connected to the end cap and the side to detect the internal air pressure of the battery cell. The data is shown in Table 2.

[0211] Table 2

[0212] 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.

[0213] Further optionally, 0.08≤S1 / S≤0.2.

[0214] As shown in FIGS. 11 to 13 , 15 , 18 and 19 , the housing 31 further has a second wall 313 intersecting the first wall 311 , and the support structure 33 is disposed between the second wall 313 and the electrode assembly 32 .

[0215] Optionally, the second wall 313 intersects the first wall 311, meaning that the second wall 313 and the first wall 311 form a predetermined angle. For example, the second wall 313 and the first wall 311 may be 90 degrees apart, or the second wall 313 and the first wall 311 may be perpendicular to each other. In other embodiments, the second wall 313 and the first wall 311 may form other angles, such as 75 degrees. This is not limited in this embodiment of the present application.

[0216] In some embodiments, the battery cell 30 is a square battery cell, and the second wall 313 includes a wall of the housing 31 perpendicular to the length direction X of the first wall 311 , and / or the second wall 313 includes a wall of the housing 31 perpendicular to the width direction Y of the first wall 311 .

[0217] In other embodiments, the battery cell 30 is a cylindrical battery cell, and the second wall 313 may include a side wall of the housing 31 .

[0218] Optionally, as shown in FIGS. 11 to 13 , the second support member 332 is fixedly connected to the second wall 313 .

[0219] Optionally, the second support member 332 can be fixedly connected to the second wall 313 by welding. Alternatively, the second support member 332 can be fixedly connected to the second wall 313 by other means such as clamping, bonding or riveting.

[0220] In this embodiment, a second support member 332 is fixedly provided on the second wall 313 of the outer shell 31 which is perpendicular to the first wall 311 to support the electrode assembly 32. This helps prevent the end of the electrode assembly 32 from moving toward the first wall 311 when thermal runaway occurs in the battery cell 30, thereby increasing the probability of forming an exhaust channel A between the first wall 311 and the electrode assembly 32 when thermal runaway occurs in the battery cell 30.

[0221] In some other embodiments, the first support member 331 and the second support member 332 may be combined, that is, the battery cell 30 includes both the first support member 331 as shown in FIG. 5 to FIG. 10 and the second support member 332 as shown in FIG. 11 .

[0222] 11 , the second wall 313 forms an accommodation space with an opening 314 , the first wall 311 covers the opening 314 to dispose the electrode assembly 32 in the accommodation space, and the second support member 332 is disposed at the opening 314 .

[0223] In this embodiment, by arranging the second support member 332 at the opening 314 of the accommodating space formed by the second wall 313, the possibility of blocking the end of the electrode assembly 32 from moving toward the first wall 311 can be increased, thereby increasing the probability of forming an exhaust channel A between the first wall 311 and the electrode assembly 32 when thermal runaway occurs in the battery cell 30.

[0224] In other examples, the second support member 332 may be disposed between a surface of the electrode assembly 32 parallel to the second wall 313 and the second wall 313, and the second support member 332 may be located at different positions on the second wall 313 along the thickness direction Z of the first wall 311. For example, along the thickness direction Z of the first wall 311, the second support member 332 may be disposed in a region of the second wall 313 that is away from the first wall 311. For another example, along the thickness direction Z of the first wall 311, the second support member 332 may be disposed in a central region of the second wall 313. In this embodiment, the presence of the second support member 332 may create a gap between the electrode assembly 32 and the second wall 313 of the housing 31. This gap may be the gap 36 shown in FIG9 . That is, the gap 36 in FIG9 may be formed by the second support member 332.

[0225] Optionally, as shown in FIG. 12 , the second support member 332 is provided with a second cavity 37 penetrating along the thickness direction Z of the first wall 311 , and the second cavity 37 is used to guide the thermal runaway gas accumulated between the second wall 313 and the electrode assembly 32 to the exhaust channel A.

[0226] In this embodiment, by providing the second support member 332 with a second cavity 37 that passes through the first wall 311 in the thickness direction Z, the electrode assembly 32 can be supported by the second support member 332 to reduce the possibility of the end of the electrode assembly 32 moving toward the first wall 311, and the thermal runaway gas accumulated between the second wall 313 and the electrode assembly 32 can be guided to the exhaust channel A through the second cavity 37, thereby reducing the possibility of non-directional pressure release of the battery cell 30.

[0227] It should be noted that the implementation of the second cavity 37 of the second support member 332 may refer to the first cavity 35 of the first support member 331 .

[0228] For example, as shown in FIG. 12 , the second support member 332 includes a plurality of second support blocks 3320 spaced apart along the circumference of the opening 314 , and the second cavity 37 includes a space 371 between every two adjacent second support blocks 3320 in the plurality of second support blocks 3320 .

[0229] For another example, at least one through hole penetrating the first wall 311 along the thickness direction Z may be provided in the second support member 332. The second cavity 37 includes the at least one through hole.

[0230] In some embodiments, the second support blocks 3320 may not be disposed at the opening 314 along the thickness direction Z of the first wall 311 . In other embodiments, the second support blocks 3320 may be disposed at different positions of the second wall 313 along the thickness direction Z of the first wall 311 .

[0231] In this embodiment, a plurality of second support blocks 3320 are arranged at intervals along the circumference of the opening 314 to form a second cavity 37, which can reduce the possibility that the thermal runaway gas accumulated between the second wall 313 and the electrode assembly 32 will not be exhausted in time and the shell 31 will be broken.

[0232] In one example, if the battery cell 30 is a square battery cell, the second wall 313 may only include side walls that are oppositely arranged along the length direction X, or the second wall 313 may only include side walls that are oppositely arranged along the width direction Y.

[0233] Optionally, as shown in Figure 13, in the thickness direction Z of the first wall 311, the surface 3321 of the second support member 332 away from the first wall 311 is closer to the first wall 311 than the surface 320 of the electrode assembly 32 close to the first wall 311; and in the thickness direction Z of the first wall 311, the projection of the second support member 332 on the first wall 311 and the projection of the electrode assembly 32 on the first wall 311 have an intersection.

[0234] In this embodiment, in the thickness direction Z of the first wall 311, the second support member 332 has an intersection between the projection of the first wall 311 and the projection of the electrode assembly 32 on the first wall 311, and the second support member 332 is closer to the first wall 311 than the electrode assembly 32, so that when the battery cell 30 has thermal runaway, the second support member 332 can block the electrode assembly 32 from approaching the first wall 311, thereby forming an exhaust channel A between the first wall 311 and the electrode assembly 32, reducing the possibility of non-directional pressure release of the battery cell 30.

[0235] As shown in Figures 8 and 14 to 19, the battery cell 30 also includes: an insulating component 40, which is arranged between the outer shell 31 and the electrode assembly 32 and is used to insulate the outer shell 31 and the electrode assembly 32; the support structure 33 includes a third support member 333, which is fixedly connected to the insulating component 40, and the third support member 333 is arranged between the outer shell 31 and the insulating component 40.

[0236] In this embodiment, a third support member 333 is provided between the outer shell 31 and the electrode assembly 32 and the insulating assembly 40, and the third support member 333 is fixedly connected to the insulating assembly 40 to support the electrode assembly 32. This is beneficial in reducing the possibility of the electrode assembly 32 moving toward the first wall 311 when thermal runaway occurs in the battery cell, thereby increasing the probability of forming an exhaust channel A between the first wall 311 and the electrode assembly 32.

[0237] In one embodiment, as shown in FIG8 , the insulating assembly 40 includes a first insulating member 34 disposed between the first wall 311 and the electrode assembly 32. In this case, the third support member may be a first support member 331 fixedly connected to the first insulating member 34. For this embodiment, reference may be made to the description of FIG8 , and for the sake of brevity, further description is omitted here.

[0238] In another embodiment, as shown in FIG. 14 to FIG. 19 , the insulating assembly 40 includes a second insulating member 38 covering the outer surface of the electrode assembly 32 ; and a third support member 333 is fixedly connected to the second insulating member 38 .

[0239] In order to better isolate the electrode assembly 32 from the housing 31, an insulating film is usually coated on the outer surface of the electrode assembly 32, that is, the second insulating member 38 in the embodiment of the present application. For example, the second insulating member 38 can be a mylar film.

[0240] 14 , a third support member 333 may be fixedly disposed on a surface of the second insulating member 38 perpendicular to the thickness direction Z of the first wall 311 and closer to the first wall 311 , so that the third support member 333 is disposed between the first wall 311 and the electrode assembly 32 .

[0241] Optionally, as shown in FIG. 15 , a third support member 333 may be fixedly disposed on a surface of the second insulating member 38 that is perpendicular to the first wall 311 , such that the third support member 333 is disposed between the second wall 313 and the electrode assembly 32 .

[0242] In this embodiment, by fixing the third support member 333 to the second insulating member 38 covering the outer surface of the electrode assembly 32 to support the electrode assembly 32, it is beneficial to reduce the possibility of the electrode assembly 32 moving toward the first wall 311 when thermal runaway occurs in the battery cell 30, thereby increasing the probability of forming an exhaust channel A between the first wall 311 and the electrode assembly 32.

[0243] In one example, when the third support member 333 is fixedly disposed on the surface of the second insulating component 38 that is perpendicular to the first wall 311, the presence of the third support member 333 creates a gap between the second wall 313 and the second insulating component 38, that is, the gap 36 shown in Figure 4 can be realized by the third support member 333.

[0244] In another example, when the third support member 333 is fixedly arranged on the surface of the second insulating member 38 perpendicular to the thickness direction Z of the first wall 311 and closer to the first wall 311, the opening of the avoidance cavity 341 in the second insulating member 34 shown in Figure 5 can face the electrode assembly 32, and the third support member 333 is accommodated in the avoidance cavity 341.

[0245] Optionally, as shown in FIG. 18 , the third support member 333 has a second through hole 3332 , which is used to release the thermal runaway gas generated by the electrode assembly 32 to between the second insulating member 38 and the housing 31 .

[0246] Optionally, the second through hole 3332 may also be used for infiltrating electrolyte.

[0247] In this embodiment, by setting a second through hole 3332 in the third support member 333, the thermal runaway gas generated by the electrode assembly 32 can be released in time between the second insulating member 38 and the outer shell 31, so that the thermal runaway gas can be further guided to the exhaust channel A, so that the thermal runaway gas can be discharged through the pressure relief mechanism 312.

[0248] Optionally, as shown in FIG. 19 , the third support member 333 is provided with a groove 3333 opening toward the housing 31 .

[0249] Optionally, the cross-sectional shape of the groove 3333 may be circular or square, which is not limited in the embodiment of the present application.

[0250] In some embodiments, the second through hole 3332 and the groove 3333 may also be combined with each other. For example, the second through hole 3332 is provided on the bottom wall of the groove 3333 .

[0251] In this embodiment, by providing a groove 3333 with an opening toward the housing 31 in the third support member 333 , on the one hand, the accommodation space for thermal runaway gas can be increased, and on the other hand, the weight of the battery cell 30 can be reduced, thereby improving the energy density of the battery cell 30 .

[0252] In one example, as shown in Figure 16, the third support member 333 and the insulating assembly 40 can be fixedly connected by snapping. For example, the third support member 333 is provided with a protrusion, and the second insulating member is provided with a groove or a through hole, and the two cooperate with each other.

[0253] In this embodiment, the third support member 333 is fixedly connected to the insulating assembly 40 by snapping, which can improve the bonding strength between the third support member 333 and the insulating assembly 40 and reduce the probability of the third support member 333 moving inside the battery cell 30 to block the exhaust channel A.

[0254] In another example, as shown in FIG17 , the third support member 333 and the insulating assembly 40 may be fixedly connected by bonding. For example, the third support member 333 and the insulating assembly 40 may be fixedly connected by a fixing glue 39 .

[0255] In this embodiment, the third support member 333 and the insulating assembly 40 can be fixedly connected by bonding, which can improve the bonding strength between the third support member 333 and the insulating assembly 40 and reduce the probability of the third support member 333 moving inside the battery cell 30 to block the exhaust channel A.

[0256] As shown in Figure 20, the battery cell 30 also includes a support plate 41, which is arranged below the electrode assembly 32 along the gravity direction G. The support structure 33 includes a fourth support member 334, which is arranged below the electrode assembly 32 along the gravity direction G. The melting point of the fourth support member 334 is higher than the melting point of the support plate 41.

[0257] The support plate 41 , also referred to as a bottom guard plate, is generally a flat plate structure and is disposed at the bottom of the battery cell to support and protect the electrode assembly.

[0258] Optionally, the fourth support member 334 may be disposed between the electrode assembly 32 and the support plate 41 , or between the support plate 41 and the wall of the housing 31 .

[0259] In some embodiments, the gravity direction G can also be considered as the thickness direction Z of the first wall 311. In this case, the first wall 311 can be the wall closer to the support plate 41 along the gravity direction G, for example, the first wall 311 can be the bottom wall of the housing 31. Alternatively, the first wall 311 can also be the wall of the housing 31 farther from the support plate 41 along the gravity direction G, for example, the first wall 311 can be the top wall of the housing 31.

[0260] Furthermore, the support plate 41 may be made of a metal material or other material capable of supporting the electrode assembly 32. In the embodiment of the present application, the melting point of the fourth support member 334 is higher than that of the support plate 41. This allows the fourth support member 334 to remain relatively stable even if the support plate 41 melts in the event of thermal runaway of the battery cell 30. The fourth support member 334 can still support the electrode assembly 32 and form a space to accommodate thermal runaway gases, thereby reducing the possibility of non-directional pressure relief in the battery cell 30.

[0261] Optionally, the fourth support member 334 is fixedly connected to the support plate 41 .

[0262] In this embodiment, by fixedly connecting the fourth support member 334 to the support plate 41 , a space for accommodating thermal runaway gas is formed between the electrode assembly 32 and the support plate 41 , thereby reducing the possibility of non-directional pressure release of the battery cell 30 .

[0263] In other embodiments, the fourth support member 334 may also be fixedly connected to a wall of the housing 31 opposite to the first wall 311 along the thickness direction Z of the first wall 311 . For example, the fourth support member 334 may be fixedly connected to the bottom wall of the housing 31 .

[0264] It should be noted that the first support member 331 , the second support member 332 , the third support member 333 and the fourth support member 334 in the embodiment of the present application can be combined with each other, and the embodiment of the present application does not limit this.

[0265] Optionally, as shown in FIG. 5 , FIG. 11 , FIG. 14 and FIG. 15 , the battery cell 30 further includes an electrode terminal 316 disposed on the first wall 311 , and the electrode terminal 316 is electrically connected to the electrode assembly 32 .

[0266] In this embodiment, the electrical connection between the electrode terminal 316 provided on the first wall 311 and the electrode assembly 32 can achieve electrical connection with other battery cells, thereby achieving the purpose of expanding the battery capacity.

[0267] Optionally, in some embodiments, the electrode terminal 316 may be disposed on a side of the first wall 311 away from the electrode assembly 32 , thereby reducing the internal space occupied by the battery cell 30 and improving the energy density of the battery cell 30 .

[0268] Referring again to Figures 4 to 20 , the battery cell 30 includes a housing 31 having a first wall 311 on which an electrode terminal 316 and a pressure relief mechanism 312 are disposed. The electrode terminal 316 is disposed on the exterior of the housing 31; an electrode assembly 32 housed within the housing 31 and electrically connected to the electrode terminal 316; and a support structure 33 disposed between the electrode assembly 32 and the housing 31. The support structure 33 is configured to form an exhaust channel A between the first wall 311 and the electrode assembly 32, which communicates with the pressure relief mechanism 312. The support structure 33 includes a first support member 331 disposed between the first wall 311 and the electrode assembly and fixed to the first wall 311; and a second support member 332 disposed between the second wall 313 of the housing 31 and the electrode assembly 32 and fixed to the second wall 313. The second wall 313 is perpendicular to the first wall 311. The battery cell 30 also includes a first insulating member 34 disposed between the electrode assembly 32 and the first wall 311. The first insulating member 34 is provided with a relief cavity 341 for accommodating a first support member 331. The first support member 331 has a higher melting point than the first insulating member 34. In the thickness direction Z of the first wall 311, the projection of the first support member 331 onto the first wall 311 is disposed at an end region of the first wall 311 along a first direction perpendicular to the thickness direction Z of the first wall 311. In the first direction, a gap 36 is defined between the electrode assembly 32 and the housing 31. The first support member 331 is provided with a first cavity 35 extending along the first direction, connecting the gap 36 with the pressure relief mechanism 312.

[0269] In this embodiment, a first support member 331 is provided between the first wall 311 and the electrode assembly 32 to support the electrode assembly 32, so that an exhaust channel A is formed between the first wall 311 and the electrode assembly 32 to guide the thermal runaway gas to the pressure relief mechanism 312. The thermal runaway gas can be discharged through the pressure relief mechanism 312 in a timely manner, thereby reducing the probability of non-directional pressure relief of the battery cell 30. Furthermore, by disposing the second support member 332 between the second wall 313 and the electrode assembly 32, a gap 36 for accommodating thermal runaway gases can be formed between the second wall 313 and the electrode assembly 32. Furthermore, the gap 36 is connected to the pressure relief mechanism 312 via the first cavity 35 provided in the first support member 331. This allows the thermal runaway gases to be promptly discharged through the pressure relief mechanism 312, thereby reducing the probability of non-directional pressure relief in the battery cell 30. Furthermore, by accommodating the first support member 331 within the escape cavity 341 of the first insulating member 34, the energy density of the battery cell 30 can be increased. Furthermore, because the melting point of the first support member 331 is higher than that of the first insulating member 34, in the event of thermal runaway in the battery cell 30, even if the first insulating member 34 melts, causing the electrode assembly 32 to move closer to the first wall 311, the first support member 331 will not melt, thereby preventing the movement of the electrode assembly 32. Consequently, an exhaust channel can still be formed between the first wall 311 and the electrode assembly 32 to guide the thermal runaway gases to the pressure relief mechanism 312.

[0270] Optionally, the battery cell 30 may further include other components, such as the connecting member 23 shown in FIG. 3 , which will not be described in detail here for the sake of brevity.

[0271] 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.

[0272] 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.

[0273] The electric device may be a vehicle as shown in FIG1 , or any device using a battery.

[0274] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described 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 encompasses all technical solutions within the scope of the claims.

Claims

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

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 support structure includes a first support member disposed between the first wall and the electrode assembly.

5. The battery cell according to claim 4, characterized in that: The first supporting member is fixedly connected to the first wall.

6. The battery cell according to claim 4, characterized in that: The first support member is integrally formed with the first wall.

7. The battery cell according to any one of claims 4 to 6, characterized in that: The battery cell further comprises: a first insulating member disposed between the electrode assembly and the first wall; Wherein, the first insulating component is provided with an avoidance cavity, and the avoidance cavity is used to accommodate the first support member.

8. The battery cell according to any one of claims 4 to 7, characterized in that: The battery cell further includes a first insulating member for insulating the first wall and the electrode assembly, and the first support has a higher melting point than that of the first insulating member.

9. The battery cell according to any one of claims 4 to 8, characterized in that: In the thickness direction of the first wall, a projection of the first support member on the first wall is arranged at an end region of the first wall along a first direction, and the first direction is perpendicular to the thickness direction of the first wall.

10. The battery cell according to claim 9, characterized in that: In the first direction, there is a gap between the electrode assembly and the housing, and the first support member is provided with a first cavity penetrating along the first direction, and the first cavity is used to connect the gap and the pressure relief mechanism.

11. The battery cell according to claim 10, characterized in that: The first support member is provided with at least one first through hole penetrating along the first direction, and the first cavity includes the at least one first through hole.

12. The battery cell according to claim 10, characterized in that: The first support member includes a plurality of first support blocks spaced apart in a second direction, the first cavity includes a space between every two adjacent first support blocks among the plurality of first support blocks, 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 any one of claims 4 to 12, characterized in that: In the thickness direction of the first wall, a dimension h of the first support member and a dimension c of the battery cell satisfy the following relationship: 0.003≤h / c≤0.

13.

14. The battery cell according to any one of claims 4 to 13, characterized in that: At least one first support member is arranged between the first wall and the electrode assembly. In the thickness direction of the first wall, the total projected area S1 of the at least one first support member on the first wall and the area S of the first wall satisfy: 0.012≤S1 / S≤0.

26.

15. The battery cell according to any one of claims 1 to 14, characterized in that: The housing further comprises a second wall intersecting with the first wall, and the supporting structure comprises a second supporting member fixedly connected with the second wall.

16. The battery cell according to claim 15, characterized in that: The second wall forms a receiving space with an opening, the first wall covers the opening to arrange the electrode assembly in the receiving space, and the second support member is arranged at the opening.

17. The battery cell according to claim 16, characterized in that: The second support member is provided with a second cavity penetrating along a thickness direction of the first wall, and the second cavity is used to guide the thermal runaway gas accumulated between the second wall and the electrode assembly to the exhaust channel.

18. The battery cell according to claim 17, characterized in that: The second support member includes a plurality of second support blocks arranged at intervals along the circumferential direction of the opening, and the second cavity includes an interval between every two of the plurality of second support blocks.

19. The battery cell according to any one of claims 15 to 18, characterized in that: In the thickness direction of the first wall, a surface of the second support member away from the first wall is closer to the first wall than a surface of the electrode assembly close to the first wall; In the thickness direction of the first wall, the second support member has an intersection between a projection of the second support member on the first wall and a projection of the electrode assembly on the first wall.

20. The battery cell according to any one of claims 1 to 19, characterized in that: The battery cell further comprises: An insulating assembly, disposed between the housing and the electrode assembly, for insulating the housing from the electrode assembly; The supporting structure comprises a third supporting member, the third supporting member is fixedly connected to the insulating assembly, and the third supporting member is arranged between the housing and the insulating assembly.

21. The battery cell according to claim 20, characterized in that: The insulating assembly includes a first insulating member, the first insulating member is disposed between the first wall and the electrode assembly, and the third support is fixedly connected to the first insulating member.

22. The battery cell according to claim 20 or 21, characterized in that: The insulating assembly includes a second insulating component, the second insulating component is coated on the outer surface of the electrode assembly, and the third support is fixedly connected to the second insulating component.

23. The battery cell according to claim 22, characterized in that: The third support member has a second through hole, and the second through hole is used to release the thermal runaway gas generated by the electrode assembly to between the insulation assembly and the housing.

24. The battery cell according to claim 22 or 23, characterized in that: The third support member is provided with a groove opening toward the housing.

25. The battery cell according to any one of claims 20 to 24, characterized in that: The third support member is fixedly connected to the insulating assembly by means of a snap connection.

26. The battery cell according to any one of claims 20 to 24, characterized in that: The third support member is fixedly connected to the insulating assembly by bonding.

27. The battery cell according to any one of claims 1 to 26, characterized in that: The battery cell further comprises: A support plate, disposed between the electrode assembly and the housing, and located below the electrode assembly in the direction of gravity; The support structure includes a fourth support member disposed below the electrode assembly along the gravity direction, and the melting point of the fourth support member is higher than the melting point of the support plate.

28. The battery cell according to claim 27, characterized in that: The fourth support member is fixedly connected to the support plate.

29. The battery cell according to any one of claims 1 to 28, characterized in that: The first wall is an end cap.

30. The battery cell according to any one of claims 1 to 29, 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.

31. A battery, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 30.

32. An electrical device, characterized in that: Comprising the battery as claimed in claim 31, wherein the battery is used to provide electrical energy to the electrical device.

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