Battery cell, battery and electric device

Abstract

A battery cell, a battery and an electric device, which can improve the pressure relief capability of the battery cell. The battery cell comprises: an electrode assembly; an end cap assembly, which comprises an end cap and an insulator located between the end cap and the electrode assembly, wherein the end cap is provided with a pressure relief mechanism, a second discharging hole is provided at a position of the insulator corresponding to the pressure relief mechanism, and the second discharging hole penetrates through the insulator in a thickness direction of the end cap assembly; and a support member, which is arranged between the insulator and the electrode assembly, wherein a first discharging hole is provided at a position of the support member corresponding to the pressure relief mechanism, and the first discharging hole penetrates through the support member in the thickness direction.

Description

Battery cells, batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202310983654.X, filed on August 7, 2023, entitled “Battery Cell, Battery and Electrical Device,” the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become a crucial component of this sustainable development. Battery technology is a crucial factor in the development of electric vehicles. Batteries are composed of single cells, each equipped with a pressure relief mechanism to release internal pressure. Improving the pressure relief capability of these cells has become a pressing issue.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can improve the pressure relief capability of the battery cell.

[0007] In a first aspect, a battery cell is provided, comprising: an electrode assembly; an end cap assembly, comprising an end cap, and an insulating member located between the end cap and the electrode assembly, the end cap being provided with a pressure relief mechanism, a second drain hole being provided on the insulating member at a position corresponding to the pressure relief mechanism, the second drain hole penetrating the insulating member along a thickness direction of the end cap assembly; and a support member, disposed between the insulating member and the electrode assembly, a first drain hole being provided on the support member at a position corresponding to the pressure relief mechanism, the first drain hole penetrating the support member along the thickness direction.

[0008] In an embodiment of the present application, the battery cell releases its internal pressure through a pressure relief mechanism on its end cap assembly. A support member is provided between the end cap assembly and the electrode assembly, which can provide support between the electrode assembly and the end cap assembly. In particular, for an inverted battery cell, the electrode assembly can be supported so that the gravity of the electrode assembly is not easily transferred to the tab and causes risks. The support member is located between the insulating member in the end cap assembly and the electrode assembly. A second discharge hole is provided on the insulating member at a position corresponding to the pressure relief mechanism, which passes through the insulating member. A first discharge hole is provided on the support member at a position corresponding to the pressure relief mechanism, which passes through the support member. Gas and other emissions from the battery cell pass through the first discharge hole on the support member and the second discharge hole on the insulating member, and are discharged to the outside of the battery cell through the pressure relief mechanism to achieve pressure relief, thereby improving the pressure relief capacity of the battery cell. At the same time, the first discharge hole can also reduce the weight of the support member.

[0009] In some possible implementations, the projection of the first drain hole on a plane perpendicular to the thickness direction does not overlap with the projection of the second drain hole on the plane. This increases the total drain area and improves drain efficiency. For example, the projection of the second drain hole on the plane may encompass the projection of the first drain hole on the plane.

[0010] The projection of the second drain hole on a plane perpendicular to the thickness direction can be, for example, an annular shape, which can be, for example, a circular or elliptical ring. Providing the second drain hole in an annular shape allows gases and other emissions from the battery cell to be uniformly discharged in all directions within a limited area, thereby achieving better drainage performance.

[0011] In some possible implementations, the projection of the first drain hole on a plane perpendicular to the thickness direction at least partially overlaps with the projection of the second drain hole on the same plane. This shortens the discharge path between the first and second drain holes, allowing gas and other emissions from the battery cell to pass through the first drain hole on the support member and quickly reach the pressure relief mechanism through the second drain hole on the insulating member after passing through the first drain hole on the support member, where they are discharged from the pressure relief mechanism. This effectively relieves pressure and improves discharge efficiency.

[0012] For example, the first drain hole includes a first sub-drain hole and a second sub-drain hole, the projection of the second drain hole on the plane surrounds the projection of the first sub-drain hole on the plane, and the projection of the second sub-drain hole on the plane overlaps with the projection of the second drain hole on the plane. By providing the first and second sub-drain holes, the drain area is increased, the drain path is shortened, and the drain efficiency is improved.

[0013] In some possible implementations, the projection of the second discharge hole on a plane perpendicular to the thickness direction is a ring, and the radial size of the ring is smaller than or equal to the radial size of the second sub-discharge hole, thereby reducing the obstruction of the second discharge hole by the first discharge hole, which is beneficial to the discharge performance.

[0014] In some possible implementations, the area of ​​the first sub-drainage hole is greater than or equal to the area of ​​the second sub-drainage hole. Setting the area of ​​the first sub-drainage hole larger than the area of ​​the second sub-drainage hole can fully utilize the area of ​​the inner region of the support member corresponding to the area surrounded by the second drain hole, thereby improving drainage efficiency and reducing the weight of the support member.

[0015] In some possible implementations, a first protrusion is provided on the insulating member and is protruded toward the supporting member, and the second drain hole is at least partially located on the first protrusion.

[0016] Providing a first protrusion on the insulating member increases the contact area between the insulating member and the thin film material on the surface of the electrode assembly, facilitating connection between the insulating member and the thin film material and improving connection reliability. Furthermore, the protrusion on the insulating member can mate with a corresponding recess provided on the support member, further improving the connection reliability between the insulating member and the support member.

[0017] In some possible implementations, a step is provided at an end of the first protrusion along the width direction of the end cover assembly, and a notch is formed inwardly along the side of the support member along the length direction of the end cover assembly to avoid the step.

[0018] In this implementation, the first protrusion of the support member is provided with a step along the width direction of its end cover assembly, and a notch is formed inwardly on the side of the support member along the length direction of the end cover assembly to avoid the step. The portion of the support member corresponding to the first protrusion can be accommodated in the step, so that the assembled support member is flush with the surface of the insulating member.

[0019] In some possible implementations, a gap is provided between an edge of the step and an edge of the notch along the width direction, and the gap is used to avoid a portion of the second drain hole provided along the edge of the step.

[0020] A certain gap is set between the edge of the step on the insulating part and the notch on the support part for avoiding the step, which can avoid the part of the second discharge hole on the insulating part set along the edge of the step, reduce the obstruction of the second discharge hole by the support part, and help improve the discharge performance.

[0021] In some possible implementations, the dimension of the notch in the longitudinal direction is greater than or equal to the dimension of the portion of the second drain hole located along the edge of the step in the longitudinal direction. This notch can completely avoid the portion of the second drain hole on the insulating member located at the edge of the step in the longitudinal direction of the end cap assembly, thereby minimizing or even eliminating any obstruction of the second drain hole by the support member in the longitudinal direction, further improving drainage performance.

[0022] In some possible implementations, the support member includes a main body portion and a second protrusion portion protruding along the main body portion toward the electrode assembly, the main body portion is used to support the electrode tab of the electrode assembly, the second protrusion portion is used to support the non-tab area on the end face of the electrode assembly, and the first discharge hole is located on the second protrusion portion.

[0023] Because the electrode assembly's tab protrudes from the end face of the electrode assembly facing the support member, the support member's main body can be attached to the tab to support it, and a second protrusion on the support member, extending along the main body toward the electrode assembly, can be attached to the end face of the electrode assembly to support it. The main body and second protrusion support the tab and end face, respectively, improving support reliability. Furthermore, the first drain hole on the support member can be located on the second protrusion of the support member, opposite the pressure relief mechanism of the battery cell, facilitating the discharge of internal pressure from the battery cell.

[0024] In some possible implementations, the support member is further provided with an opening extending therethrough, the opening being located at the intersection of the main body and the second protrusion. This opening can be used to avoid the first protrusion provided on the insulating member at a position corresponding to the second protrusion, and can also reduce the weight of the support member.

[0025] In some possible implementations, on a plane perpendicular to the thickness of the end cap assembly, the projection of the opening covers the portion of the projection of the second drain hole that is not covered by the projection of the second protrusion. This opening can effectively avoid at least a portion of the second drain hole, reducing obstruction of the second drain hole by the support member, thereby improving drainage performance.

[0026] In some possible implementations, a hook portion is provided at the end of the support member located in the longitudinal direction of the end cap assembly. The hook portion engages with the insulating member to connect the support member to the end cap assembly. Providing the hook portion at the end of the support member allows for a simple and reliable connection between the support member and the insulating member.

[0027] In a second aspect, a battery is provided, comprising the battery cell described in the first aspect or any possible implementation of the first aspect.

[0028] In a third aspect, an electrical device is provided, comprising the battery described in the second aspect or any possible implementation of the second aspect, wherein the battery is used to provide electrical energy to the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] FIG1 is a schematic structural diagram of a vehicle according to an embodiment of the present application.

[0031] FIG2 is a schematic structural diagram of a battery according to an embodiment of the present application.

[0032] FIG3 is a schematic structural diagram of a battery cell according to an embodiment of the present application.

[0033] FIG4 is a schematic structural diagram of an end cover assembly according to an embodiment of the present application.

[0034] FIG5 is a schematic structural diagram of the insulating member and the supporting member before assembly according to an embodiment of the present application.

[0035] FIG6 is a schematic diagram of the insulating member and the supporting member after assembly according to an embodiment of the present application.

[0036] FIG. 7 is a partial cross-sectional view of a battery cell according to an embodiment of the present application.

[0037] FIG8 is a partial top view of the insulating member according to the embodiment of the present application.

[0038] FIG9 is a partial top view of the insulating member and the supporting member after assembly according to the embodiment of the present application.

[0039] FIG10 is a partial top view of the insulating member and the supporting member after assembly according to one embodiment of the present application.

[0040] FIG11 is a partial top view of the insulating member and the supporting member after assembly according to another embodiment of the present application.

[0041] FIG12 is a schematic structural diagram of the insulating member and the supporting member before assembly according to an embodiment of the present application.

[0042] FIG13 is a partial top view of the insulating member and the supporting member after assembly according to the embodiment of the present application.

[0043] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The term "multiple" as used in this application refers to two or more than two. Similarly, the term "multiple groups" refers to two or more than two groups, and the term "multiple sheets" refers to two or more than two sheets.

[0050] In the embodiments of the present application, the battery cells may be secondary batteries. A secondary battery refers to a battery cell that can be recharged to activate the active material after discharge and continue to be used. The battery cells may be, for example, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., although the embodiments of the present application are not limited thereto.

[0051] 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 while allowing the active ions to pass through.

[0052] In some embodiments, the positive electrode may be a positive electrode sheet, which includes a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0053] 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.

[0054] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium. 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 such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy on a polymer material substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like.

[0055] Among them, the positive electrode active material includes, for example, at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. The present application is not limited to these materials, and other traditional materials that can be used as battery positive electrode active materials can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphates 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.

[0056] In some embodiments, the negative electrode may be a negative electrode sheet, which includes a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0057] 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 one or both of the two facing surfaces of the negative electrode current collector.

[0058] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may include silver-surface-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium. The composite current collector may include a polymer base layer and a metal layer. The composite current collector may be formed by forming a metal material such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy on a polymer substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene.

[0059] The negative electrode active material includes, for example, at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and the like.

[0060] In some embodiments, the negative electrode may also use a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. It should be noted that 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.

[0061] 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.

[0062] The material of the positive electrode current collector may be, for example, aluminum, and the material of the negative electrode current collector may be, for example, copper.

[0063] The separator in the electrode assembly is disposed between the positive electrode and the negative electrode. In some embodiments, the separator is a separator membrane. This application does not limit the type of separator membrane; any porous separator membrane with good chemical and mechanical stability can be used. For example, the primary material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.

[0064] 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.

[0065] 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 limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0066] In an embodiment of the present application, the electrode assembly may be a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound to form a wound structure. The electrode assembly may also be a laminated structure, for example, the positive electrode sheet and the negative electrode sheet may be provided in a plurality, and the plurality of positive electrode sheets and the plurality of negative electrode sheets are alternately stacked. Alternatively, the positive electrode sheet may be provided in a plurality, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments; or, both the positive electrode sheet and the negative electrode sheet may be folded to form a plurality of stacked folded segments.

[0067] There may be multiple separators, each of which is disposed between any adjacent positive electrode sheets and negative electrode sheets.

[0068] In some embodiments, the separator may be provided continuously and disposed between any adjacent positive electrode sheets and negative electrode sheets by folding or winding.

[0069] The electrode assembly may be shaped, for example, cylindrical, flat, or polygonal. The electrode assembly may be provided with tabs for conducting current from the electrode assembly. The tabs include positive tabs and negative tabs.

[0070] In some embodiments, a battery cell includes a housing. The housing is used to encapsulate components such as the electrode assembly and electrolyte. The housing can be steel, aluminum, plastic such as polypropylene, composite metal such as a copper-aluminum composite, or aluminum-plastic film. The housing includes a housing and a cover.

[0071] The battery cells may be, for example, cylindrical battery cells, prismatic battery cells, soft-pack battery cells or battery cells of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells or polygonal batteries, among which polygonal batteries may be hexagonal batteries, etc. This application does not impose any restrictions on this.

[0072] The battery described in the embodiments of the present application can be a single physical module including one or more battery cells to provide higher voltage and capacity. In the case of multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid through a busbar.

[0073] 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.

[0074] 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.

[0075] 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 vehicle floor, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0076] The battery cells in the battery usually release their internal pressure through the pressure relief mechanism on their end cover assembly to reduce the risk of thermal runaway of the battery. A support member can be set between the end cover assembly and the electrode assembly to play a supporting role, but the support member will affect the release of the internal pressure of the battery cell.

[0077] In view of this, the present application provides a battery cell, which provides a discharge hole at a position corresponding to the pressure relief mechanism on the support member, so that the gas and other emissions inside the battery cell pass through the discharge hole and are discharged from the pressure relief mechanism to achieve effective pressure relief.

[0078] The technical solutions described in the embodiments of the present application are applicable to various battery-using 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.

[0079] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the devices described above, but can also be applied to all devices using batteries. However, for the sake of simplicity, the following embodiments are described using electric vehicles as an example.

[0080] For example, as shown in FIG1 , it is a structural 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 30, a controller 20 and a battery 10 may be provided inside the vehicle 1. The controller 20 is used to control the battery 10 to supply power to the motor 30. For example, a battery 10 may be provided at the bottom, front or rear of the vehicle 1. The battery 10 may be used to power the vehicle 1. For example, the battery 10 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 10 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.

[0081] To meet different power requirements, a battery can include multiple different types of battery cells. Multiple battery cells can be connected in series, in parallel, or in a hybrid manner according to the type of battery cell to form multiple battery cell groups, and the multiple battery cell groups are then connected in series to form a battery, where hybrid is a mixture of series and parallel connections. Multiple different battery cells can also be directly connected in series, in parallel, or in a hybrid manner to form a battery. In other words, multiple battery cells can be directly combined into a battery, or they can be first combined into battery cell groups according to the type of battery cells, and then the battery cell groups are formed into a battery.

[0082] Figure 2 shows a schematic structural diagram of a battery 10 according to an embodiment of the present application. The battery 10 may include a plurality of battery cells (not shown in the figure). The battery 10 may also include a housing (or cover) 110. The interior of the housing 110 is a hollow structure, and a plurality of battery cells are accommodated in the housing 110. The housing 110 may include two parts, referred to herein as a first housing portion 111 and a second housing portion 112, which are snapped together. The shapes of the first housing portion 111 and the second housing portion 112 may be determined according to the shape of the combination of the plurality of battery cells, and at least one of the first housing portion 111 and the second housing portion 112 has an opening.

[0083] For example, as shown in Figure 2, only one of the first box body portion 111 and the second box body portion 112 is a hollow rectangular parallelepiped with an opening, while the other is in the shape of a plate to cover the opening. Here, taking the second box body portion 112 as a hollow structure with only one open surface and the first box body portion 111 as an example, the first box body portion 111 covers the opening of the second box body portion 112 to form a box body 110 with a closed chamber, which can be used to accommodate multiple battery cells. After the multiple battery cells are connected in parallel, series, or mixed, they are placed in the box body 110 formed by the first box body portion 111 and the second box body portion 112 being fastened together.

[0084] For another example, unlike that shown in FIG2 , the first housing portion 111 and the second housing portion 112 can both be hollow structures with only one open surface. The openings of the first housing portion 111 and the second housing portion 112 are arranged opposite each other, and the first housing portion 111 and the second housing portion 112 are interlocked to form a housing 110 having a closed chamber. Multiple battery cells are connected in parallel, series, or in a mixed combination and placed in the housing 110 formed by the interlocking of the first housing portion 111 and the second housing portion 112.

[0085] In addition, the battery 10 may also include other structures. For example, the battery may also include a signal transmission component. The signal transmission component can be used to transmit signals such as the voltage and / or temperature of the battery cells. The signal transmission component may include a wiring harness board, which may include, for example, a temperature sensor and voltage sampling lines, for measuring and transmitting information such as the battery voltage, current, and temperature, and communicating with the BMS to achieve battery safety management.

[0086] In some embodiments, the signal transmission assembly may further include a busbar assembly, which is used to achieve electrical connection between multiple battery cells, such as parallel, series, or mixed connection. The busbar assembly can achieve electrical connection between battery cells by connecting to the electrode terminals of the battery cells. In some embodiments, the busbar assembly can be fixed to the electrode terminals of the battery cells by welding. The busbar assembly transmits the voltage of the battery cells. When multiple battery cells are connected in series, a higher voltage is obtained. Accordingly, the electrical connection formed by the busbar assembly can also be referred to as a "high voltage connection."

[0087] In some embodiments, the busbar assembly and wiring harness plate are encapsulated in an insulating layer to form a signal transmission assembly, also known as a CCS assembly. The signal transmission assembly is free of the insulating layer at the connection points with the electrode terminals of the battery cells. Instead, the insulating layer has openings therein for connection with the electrode terminals of the battery cells.

[0088] As an example, as shown in FIG3 , which is a schematic structural diagram of a battery cell 120 in an embodiment of the present application, the battery cell 120 includes an electrode assembly 121, an end cap assembly 122, and a support member 123. A pressure relief mechanism 124 is provided on the end cap assembly 122. The support member 123 is disposed between the end cap assembly 122 and the electrode assembly 121, and a first drain hole 1231 is provided on the support member 123 at a position corresponding to the pressure relief mechanism 124, penetrating the support member 123 along the thickness direction Z of the end cap assembly 122.

[0089] As shown in FIG3 , the surface of the electrode assembly 121 may be covered with a film material 126 , such as a polyester film. The housing 125 of the battery cell 120 is used to accommodate the electrode assembly 121. The end cap assembly 122 is used to cover the electrode assembly 121 within the housing 125 . The thickness direction Z of the end cap assembly 122 is perpendicular to the end surface 1212 of the electrode assembly 121 where the tab 1211 is located.

[0090] The first drain hole 1231 penetrates the support member 123 along the thickness direction Z. That is, the first drain hole 1231 is a through hole of the support member 123 along the thickness direction Z.

[0091] Optionally, the battery cell 120 can be an inverted battery cell, that is, when the battery 10 is set in an electrical device, the electrode terminals of the battery cell 120 are facing away from the passengers. At this time, the end cover assembly 122 is located below the electrode assembly 121. By arranging a support member 123 between the end cover assembly 122 and the electrode assembly 121 to support the electrode assembly 121, the gravity of the electrode assembly 121 is not easily transmitted to the tab 1211 and cause risks.

[0092] The battery cell 120 releases its internal pressure through the pressure relief mechanism 124 on its end cap assembly 122. By providing a first drain hole 1231 through the support member 123 at a position corresponding to the pressure relief mechanism 124, gas and other emissions from the battery cell 120 are discharged through the first drain hole 1231 and out of the pressure relief mechanism 124, achieving effective pressure relief and improving the pressure relief capability of the battery cell 120. Furthermore, the first drain hole 1231 also reduces weight.

[0093] The end cover assembly 122 includes an end cover 1221 and an insulating member 1222. The end cover 1221 and the shell 125 can be two independent components or can be integrally formed. The pressure relief mechanism 124 is provided on the end cover 1221. The pressure relief mechanism 124 can also be called an explosion-proof valve, which is used to discharge high-temperature and high-pressure emissions from the inside of the battery cell 120 when thermal runaway occurs in the battery cell 120, such as electrolyte, dissolved or split fragments of positive and negative pole pieces or separators, high-temperature and high-pressure gases or flames generated by the reaction, etc. These emissions will cause at least a portion of the pressure relief mechanism 124 to rupture, melt, split, etc., that is, open the valve, and thus be discharged to the outside of the battery cell 120 through the pressure relief mechanism 124. The pressure relief mechanism 124 and the end cover 1221 can be connected, for example, by welding, and the surface of the pressure relief mechanism can be covered with a film layer 1241.

[0094] In some embodiments, as shown in FIG4 , a second drain hole 1223 is provided on the insulating member 1222 at a position corresponding to the pressure relief mechanism 124. The second drain hole 1223 penetrates the insulating member 1222 along the thickness direction Z. By providing the second drain hole 1223 penetrating the insulating member 1222 at a position corresponding to the pressure relief mechanism 124, and providing the first drain hole 1231 penetrating the support member 123 at a position corresponding to the pressure relief mechanism 124, gas and other exhaust gases within the battery cell 120 can pass through the first drain hole 1231 on the support member 123 and the second drain hole 1223 on the insulating member 1222 and be discharged from the pressure relief mechanism 124 to the exterior of the battery cell 120, thereby achieving pressure relief and improving the pressure relief capability of the battery cell 120. The insulating member 1222, also commonly referred to as the lower plastic, is used to isolate the electrical connection components within the housing 125 from the end cap 1221 to reduce the risk of short circuits. The insulating member 1222 may be made of, for example, plastic, rubber, or other materials.

[0095] The insulating member 1222 is disposed between the end cap 1221 and the support member 123, and the insulating member 1222 and the support member 123 are connected. For example, as shown in FIG5 , the end of the support member 123 located in the length direction Y of the end cap assembly 122 is provided with a hook portion 1232. The hook portion 1232 and the insulating member 1222 hook and engage with each other to connect the support member 123 and the end cap assembly 122. By providing the hook portion 1232 on the end of the support member 123, the connection between the support member 123 and the insulating member 1222 can be conveniently achieved.

[0096] In some embodiments, as shown in FIG5 , the insulating member 1222 is provided with a first protrusion 12221 that protrudes toward the support member 123, and the second drain hole 1223 is at least partially located on the first protrusion 12221. Providing the first protrusion 12221 on the insulating member 1222 can increase the contact area between the insulating member 1222 and the thin film material 126 on the surface of the electrode assembly 121, facilitating the connection between the insulating member 1222 and the thin film material 126 and improving connection reliability. Furthermore, as shown in FIG5 , the support member 123 can form a recess 1233, and the first protrusion 12221 on the insulating member 1222 can cooperate with the recess 1233 on the support member 123 to improve the connection reliability between the insulating member 1222 and the support member 123.

[0097] In some embodiments, as shown in Figure 5, a step 12222 is provided at the end of the first protrusion 12221 along the width direction X of the end cover assembly 122, and a notch 1234 is formed inwardly along the side of the length direction Y of the end cover assembly 122 to avoid the step 12222.

[0098] After the support member 123 and the insulating member 1222 are assembled, as shown in Figures 6 and 7, Figure 6 is a three-dimensional view of the support member 123 and the insulating member 1222 after assembly, and Figure 7 is a partial cross-sectional view of the support member 123 and the insulating member 1222 after assembly, the recess 1233 of the support member 123 can accommodate the part of the first protrusion 12221 of the insulating member 1222 located between the steps 12222, and the support member 123 is accommodated in the steps 12222, so that the bottom surface of the assembled support member 123 is flush with the bottom surface of the insulating member 1222.

[0099] In some embodiments, a gap D is provided between the edge of the step 12222 and the edge of the notch 1234 along the width direction X, and the gap D is used to avoid a portion of the second discharge hole 1223 provided along the edge of the step 12222 .

[0100] For example, as shown in Figures 8 and 9 , where Figure 8 is a schematic diagram of the dimensions of insulating member 1222 and Figure 9 is a schematic diagram of the dimensions after insulating member 1222 and support member 123 are assembled, support member 123 shown in Figure 9 has a notch 1234 formed inwardly along the side edge in the length direction Y of end cap assembly 122 to avoid step 12222. A gap D is provided between the edge of step 12222 and the edge of notch 1234. Comparing the dimensions of insulating member 1222 shown in Figure 8 , it can be seen that, along the width direction X, the width W2 of notch 1234 of support member 123 is less than or equal to the minimum width W1 of second drain hole 1223 of insulating member 1222, i.e., W2 ≤ W1.

[0101] Therefore, the notch 1234 on the support member 123 can avoid the portion of the second discharge hole 1223 on the insulating member 1222 that is set along the edge of the step 12222, reducing the obstruction of the second discharge hole 1223 by the support member 123, which is conducive to improving the discharge performance.

[0102] In some embodiments, as shown in Figures 8 and 9, the dimension L2 of the notch 1234 in the length direction Y is greater than or equal to the dimension L1 of the portion of the second drain hole 1223 located along the edge of the step 12222 in the length direction Y, that is, L2 ≥ L1. In this way, the notch 1234 can completely avoid the portion of the second drain hole 1223 on the insulating member 1222 located at the edge of the step 12222 in the length direction Y of the end cap assembly 122, thereby minimizing or even eliminating any obstruction by the support member 123 to the portion of the second drain hole 1223 located along the edge of the step 12222 in the length direction, further improving drain performance.

[0103] Optionally, the sharp corners of the notch 1234 may be rounded. For example, as shown in FIG. 9 , the rounded corner R may be smaller than W2 / 2 to facilitate the process, such as 0.01≤R≤(W2 / 2)-2, where the units are all in millimeters.

[0104] In some embodiments, a projection of the first drain hole 1231 on a plane perpendicular to the thickness direction Z and a projection of the second drain hole 1223 on the plane do not overlap, or at least partially overlap.

[0105] When the projection of the first discharge hole 1231 on the plane perpendicular to the thickness direction Z does not overlap with the projection of the second discharge hole 1223 on the same plane, the total discharge area can be increased and the discharge efficiency can be improved; when there is at least a portion between the projection of the first discharge hole 1231 on the plane perpendicular to the thickness direction Z and the projection of the second discharge hole 1223 on the same plane, the discharge path between the first discharge hole 1231 and the second discharge hole 1223 can be shortened, so that the gas and other emissions inside the battery cell 120 can reach the pressure relief mechanism 124 through the second discharge hole 1223 on the insulating member 1222 as soon as possible after passing through the first discharge hole 1231 on the support member 123, and be discharged from the pressure relief mechanism 124, so as to achieve effective pressure relief and improve the discharge efficiency.

[0106] It is understood that when the first drain hole 1231 and the second drain hole 1223 do not overlap, even though the support member 123 and the insulating member 1222 can be connected together by means such as snapping, a certain gap may exist between the support member 123 and the insulating member 1222. In particular, when a battery cell 120 experiences thermal runaway, the pressure inside the battery cell 120 may cause the insulating member 1222 to deform, thereby increasing the gap between the support member 123 and the insulating member 1222. As a result, the pressure inside the battery cell 120 is discharged from the pressure relief mechanism 124 to the outside of the battery cell 120 through the first drain hole 1231 on the support member 123 and the second drain hole 1223 on the insulating member 1222. In this way, even if the first drain hole 1231 and the second drain hole 1223 do not overlap, the first drain hole 1231 and the second drain hole 1223 can still perform their corresponding discharge functions.

[0107] In some embodiments, for example, as shown in Figures 8 and 9, the second drain hole 1223 can be configured in a ring shape, that is, the projection of the second drain hole 1223 on a plane perpendicular to the thickness direction Z is a ring shape. This allows the gas and other exhaust gases inside the battery cell 120 to be uniformly discharged in all directions within a limited area, thereby achieving better discharge performance. The ring shape can be, for example, circular or elliptical.

[0108] As an example, Figure 9 illustrates a possible position of first drain hole 1231, where the projection of second drain hole 1223 on a plane perpendicular to the thickness direction Z surrounds the projection of first drain hole 1231 on the same plane. Taking the annular second drain hole 1223 as an example, first drain hole 1231 can be positioned on support member 123 corresponding to the inner area enclosed by the annular shape, so that the projection of first drain hole 1231 on a plane perpendicular to the thickness direction Z does not overlap with the projection of second drain hole 1223 on the same plane. This increases the combined drain area of ​​first drain hole 1231 and second drain hole 1223, improving drain efficiency.

[0109] As an example, Figure 10 shows another possible position of first drain hole 1231. Taking annular second drain hole 1223 as an example, first drain hole 1231 includes a first sub-drain hole 1231A and a second sub-drain hole 1231B. The projection of second drain hole 1223 on a plane perpendicular to the thickness direction Z surrounds the projection of first sub-drain hole 1231A on that plane, while the projection of second sub-drain hole 1231B on that plane overlaps with the projection of second drain hole 1223 on the plane. The provision of first sub-drain hole 1231A and second sub-drain hole 1231B increases the drain area, shortens the drain path, and improves drain efficiency.

[0110] As shown in Figure 10, the diameter D2 of the second sub-discharge hole 1231B on the support member 123 can be greater than or equal to the radial dimension D1 of the annular shape of the second discharge hole 1223, so that the obstruction of the second discharge hole 1223 by the first discharge hole 1231 can be reduced, which is conducive to improving the discharge performance.

[0111] In some embodiments, as shown in Figures 9 and 10, the area of ​​the first sub-drainage hole 1231A is greater than or equal to the area of ​​the second sub-drainage hole 1231B. Setting the area of ​​the first sub-drainage hole 1231A larger than the area of ​​the second sub-drainage hole 1231B can fully utilize the position of the support member 123 corresponding to the inner area surrounded by the second drain hole 1223, thereby improving drainage efficiency and helping to reduce the weight of the support member 123.

[0112] The number and shape of the first drain holes 1231 can be set according to actual conditions. Generally, there can be multiple first drain holes 1231, and the sizes and shapes of the multiple first drain holes 1231 can be the same or different. The number and shape of the second sub-drain holes 1231B can also be set according to actual conditions.

[0113] For example, as shown in Figure 10, the first sub-discharge hole 1231A includes an oblong hole, and the second sub-discharge hole 1231B includes a circular hole. The first sub-discharge hole 1231A is correspondingly arranged in the inner area surrounded by the ring, and the second sub-discharge hole 1231B is correspondingly arranged at the two end areas of the ring along the length direction Y and is symmetrical along the width direction X; for another example, as shown in Figure 11, the first sub-discharge hole 1231A includes an oblong hole and a circular hole, and the second sub-discharge hole 1231B includes a circular hole. The oblong hole in the first sub-discharge hole 1231A is correspondingly arranged in the inner area surrounded by the ring, and the circular hole in the first sub-discharge hole 1231A is correspondingly arranged in the end area of ​​the inner area surrounded by the ring in the length direction Y and is symmetrical along the width direction X. The second sub-discharge hole 1231B is correspondingly arranged in the areas corresponding to the two ends of the ring along the length direction Y and is symmetrical along the width direction X. The number K of the second sub-discharge holes 1231B can be set to 1≤K≤6, for example, which can ensure the discharge performance without increasing the process difficulty.

[0114] In addition to the above examples, the shape of the second sub-discharge hole 1231B may also be, for example, a circle, a rectangle, an oblong hole along the center line of the width direction X or the length direction Y of the insulating member 1222 , or the like.

[0115] In some embodiments, the support member 123 includes a main body portion 1235 and a second protrusion 1236 protruding along the main body portion 1235 toward the electrode assembly 121. The main body portion 1235 is used to support the electrode tab 1211 of the electrode assembly 121, and the second protrusion 1236 is used to support the non-pole tab area on the end face 1212 of the electrode assembly 121. The first discharge hole 1231 is located at the second protrusion 1236.

[0116] Because the tab 1211 of the electrode assembly 121 protrudes from the end surface 1212 of the electrode assembly 121 facing the support member 123, the main body 1235 of the support member 123 can be attached to the tab 1211 to support it. The second protrusion 1236 of the support member 123, which protrudes along the main body 1235 toward the electrode assembly 121, can be attached to the end surface 1212 of the electrode assembly 121 to support it. The main body 1235 and the second protrusion 1236 respectively support the tab 1211 and the end surface 1212, thereby improving the reliability of the support member 123. Furthermore, the first drain hole 1231 of the support member 123 can be located on the second protrusion 1236 of the support member 123, opposite the pressure relief mechanism 124 of the battery cell 120, facilitating the discharge of internal pressure from the battery cell 120.

[0117] For example, the tab 1211 shown in Figure 3 is usually arranged at the four corners of the end surface 1212. Therefore, the support member 123 shown in Figures 5 and 6, or the support member 123 shown in Figures 12 and 13, relative to the main body 1235, the second protrusion 1236 protrudes toward the electrode assembly 121 along the middle area of ​​the support member 123, so that the main body 1235 on the support member 123 is located at the four corners of the second protrusion 1236.

[0118] In some embodiments, the support member 123 is further provided with an opening 1237 extending through the support member 123. The opening 1237 is located at the intersection of the main body 1235 of the support member 123 and the second protrusion 1236. The opening 1237 can be used to avoid the first protrusion 12221 provided on the insulating member 1222 at a position corresponding to the second protrusion 1236, and can also reduce the weight of the support member 123.

[0119] In some embodiments, on a plane perpendicular to the thickness direction Z of the end cap assembly 122, the projection of the opening 1237 covers the portion of the projection of the second drain hole 1223 that is not covered by the projection of the second protrusion 1236. The opening 1237 can effectively avoid at least a portion of the second drain hole 1223, reducing the obstruction of the second drain hole 1223 by the support member 123, thereby improving drain performance.

[0120] As an example, as shown in Figures 12 and 13, Figure 12 is a schematic diagram of the support member 123 before being assembled with the insulating member 1222, and Figure 12 is a top view of the support member 123 after being assembled with the insulating member 1222. The main body 1235 of the support member 123 is located at the four corners of the second protrusion 1236. The main body 1235 and the second protrusion 1236 are respectively used to support the electrode tab 1211 of the electrode assembly 121 and the end surface 1212 where the electrode tab 1211 is located. The second protrusion 1236 includes a transverse portion extending along the length direction Y and a vertical portion extending along the width direction X, thereby obtaining a "cross"-shaped second protrusion 1236 having a transverse portion and a vertical portion. The vertical portion can cooperate with the first protrusion 12221 of the insulating member 1222 to accommodate the first protrusion 12221. In order to facilitate the cooperation between the vertical portion and the first protrusion 12221 of the insulating member 1222, optionally, the dimension W3 of the vertical portion of the second protrusion 1236 along the length direction Y needs to be larger than the dimension P of the first protrusion 12221 of the insulating member 1222 along the length direction Y. For a conventional battery cell 120, for example, W3 can be set to ≥ 2 mm.

[0121] In addition, in order to reduce the impact of the opening 1237 on the structural strength of the support member 123, optionally, the dimension Q of the lateral portion of the second protrusion 1236 of the support member 123 should not be set too small. For a conventional battery cell 120, for example, Q can be set to ≥ 2 mm.

[0122] Typically, the ring shape of the second discharge hole 1223 can be circular or elliptical. In the case where the ring shape of the second discharge hole 1223 is elliptical, the width direction X can be the direction of the minor axis of the ellipse, and the length direction Y can be the direction of the major axis of the ellipse, such as the cases shown in Figures 5 to 11 . Alternatively, the width direction X is the direction of the major axis of the ellipse, and the length direction Y is the direction of the minor axis of the ellipse, such as the cases shown in Figures 12 and 13 .

[0123] The present application also provides a battery, comprising the battery cell 120 described in any of the above embodiments.

[0124] The present application further provides an electrical device, comprising the battery 10 described in any of the above embodiments, wherein the battery 10 is used to provide electrical energy to the electrical device. The electrical device is, for example, the vehicle 1 described above.

[0125] As can be seen, the battery cell 120 of the present embodiment releases its internal pressure through the pressure relief mechanism 124 on its end cap assembly 122. A support member 123 can be provided between the end cap assembly 122 and the electrode assembly 121. Especially for an inverted battery cell 120, the support member 123 can effectively support the electrode assembly 121, preventing the gravity of the electrode assembly 121 from being transferred to the tab 1211 and causing risks. The end cap assembly 122 includes an end cap provided with a pressure relief mechanism 124 and an insulating member 1222. A second drain hole 1223 is provided on the insulating member 1222 at a position corresponding to the pressure relief mechanism 124. A first drain hole 1231 is provided on the support member 123 at a position corresponding to the pressure relief mechanism 124 and passes through the support member 123. The first drain hole 1231 and the second drain hole 1223 may not overlap or at least partially overlap. In this way, the high-temperature and high-pressure exhaust inside the battery cell 120 can pass through the first exhaust hole 1231 and the second exhaust hole 1223 and be discharged from the pressure relief mechanism 124, thereby achieving effective pressure relief and improving the pressure relief capability of the battery cell 120. At the same time, the first exhaust hole 1231 can also play a role in weight reduction.

[0126] It should be noted that, under the premise of no conflict, the various embodiments and / or technical features in each embodiment described in this application can be arbitrarily combined with each other, and the technical solution obtained after the combination should also fall within the scope of protection of this application.

[0127] 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: Electrode assembly; an end cap assembly, comprising an end cap, and an insulating member located between the end cap and the electrode assembly, wherein the end cap is provided with a pressure relief mechanism, and a second discharge hole is provided on the insulating member at a position corresponding to the pressure relief mechanism, and the second discharge hole penetrates the insulating member along a thickness direction of the end cap assembly; and A support member is disposed between the insulating member and the electrode assembly. A first discharge hole is disposed on the support member at a position corresponding to the pressure relief mechanism. The first discharge hole penetrates the support member along the thickness direction.

2. The battery cell according to claim 1, characterized in that: A projection of the first discharge hole on a plane perpendicular to the thickness direction does not overlap with a projection of the second discharge hole on the plane.

3. The battery cell according to claim 2, characterized in that: A projection of the second discharge hole on the plane surrounds a projection of the first discharge hole on the plane.

4. The battery cell according to claim 3, characterized in that: A projection of the second discharge hole on a plane perpendicular to the thickness direction is annular.

5. The battery cell according to claim 1, characterized in that: A projection of the first discharge hole on a plane perpendicular to the thickness direction at least partially overlaps with a projection of the second discharge hole on the plane.

6. The battery cell according to claim 5, characterized in that: The first discharge hole includes a first sub-discharge hole and a second sub-discharge hole, a projection of the second discharge hole on the plane surrounds a projection of the first sub-discharge hole on the plane, and a projection of the second sub-discharge hole on the plane overlaps with a projection of the second discharge hole on the plane.

7. The battery cell according to claim 6, characterized in that: The projection of the second discharge hole on a plane perpendicular to the thickness direction is a ring shape, and a dimension of the ring along a radial direction is smaller than or equal to a dimension of the second sub-discharge hole along the radial direction.

8. The battery cell according to claim 6 or 7, characterized in that: An area of ​​the first sub-discharge hole is greater than or equal to an area of ​​the second sub-discharge hole.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The insulating member is provided with a first protruding portion protruding toward the supporting member, and the second discharge hole is at least partially located on the first protruding portion.

10. The battery cell according to claim 9, characterized in that: The first protrusion is provided with a step at the end portion along the width direction of the end cover assembly, and the support member is formed with a notch inwardly along the side edge along the length direction of the end cover assembly for avoiding the step.

11. The battery cell according to claim 10, characterized in that: A gap is arranged between the edge of the step and the edge of the notch along the width direction, and the gap is used to avoid a portion of the second discharge hole arranged along the edge of the step.

12. The battery cell according to claim 11, characterized in that: A dimension of the notch in the length direction is greater than or equal to a dimension of a portion of the second discharge hole arranged along the edge of the step in the length direction.

13. The battery cell according to any one of claims 1 to 12, characterized in that: The support member includes a main body portion and a second protrusion portion protruding along the main body portion toward the electrode assembly, the main body portion is used to support the pole ear of the electrode assembly, the second protrusion portion is used to support the non-pole ear area on the end surface of the electrode assembly, and the first discharge hole is located at the second protrusion portion.

14. The battery cell according to claim 13, characterized in that: The support member is also provided with an opening penetrating the support member, and the opening is located at a position where the main body and the second protruding portion intersect.

15. The battery cell according to claim 14, characterized in that: On a plane perpendicular to the thickness direction of the end cover assembly, the projection of the opening covers a portion of the projection of the second discharge hole that is not covered by the projection of the second protrusion.

16. The battery cell according to any one of claims 1 to 15, characterized in that: A hook portion is provided at the end of the support member in the length direction of the end cover assembly, and the hook portion is hooked and matched with the insulating member to connect the support member and the end cover assembly.

17. A battery, characterized in that: The invention comprises at least one battery cell according to any one of claims 1 to 16.

18. An electrical device, characterized in that: The battery according to claim 17 is used to provide power for the electrical device.

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