Battery monomer and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery monomer and a battery pack, the battery monomer comprises a shell, an end cover, an electrode assembly and a supporting piece; the end cover is provided with an opening part, the opening part is blocked by the end cover, the end cover is connected with the shell to form a containing space, the end cover comprises an end cover body and a first insulating part, and the first insulating part is arranged on the side, facing the containing space, of the end cover body; the electrode assembly is arranged in the accommodating space and comprises an electrode body and a first tab; the supporting piece is arranged between the electrode body and the first insulating piece, the supporting piece comprises a supporting part and a bearing part, and the supporting part protrudes towards the direction of the electrode body relative to the bearing part to form a first convex part and a first concave part which are opposite to each other; a liquid injection hole is formed in the end cover, the projection of the liquid injection hole and the projection of the first concave part are at least partially overlapped in the thickness direction of the end cover, and a first via hole communicating the first concave part with the containing space is further formed in the first convex part. The liquid injection device has the beneficial effect that the liquid injection efficiency and the liquid injection effect of the battery are improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell and a battery pack. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In battery manufacturing, the electrolyte injection process is a crucial step. Therefore, improving the efficiency and effectiveness of electrolyte injection is a technical problem that needs to be solved. Utility Model Content

[0004] This application provides a battery cell and a battery pack, which improves the electrolyte injection efficiency and effect of the battery cell.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include:

[0006] This application provides a battery cell including a housing, an end cap, an electrode assembly, and a support member. The housing has an opening, and the end cap seals the opening. The end cap is connected to the housing to form a receiving space. The end cap includes an end cap body and a first insulating member, which is disposed on the side of the end cap body facing the receiving space. The electrode assembly is disposed in the receiving space and includes an electrode body and a first tab. The support member is disposed between the electrode body and the first insulating member and includes a support portion and a bearing portion. The support portion protrudes relative to the bearing portion in the direction facing the electrode body to form a first protrusion and a first recess that are opposite to each other. The end cap is provided with a liquid injection hole. Along the thickness direction of the end cap, the projection of the liquid injection hole at least partially overlaps with the projection of the first recess. The first protrusion is also provided with a first through hole connecting the first recess and the receiving space.

[0007] The battery cell proposed in this application embodiment has a support member located between the electrode body and the first insulating member, which supports the electrode body. The first insulating member forms an insulating barrier between the support member and the end cap. The bearing portion supports the first insulating member, such that the edge and center of the support member support the first support member and the electrode body, respectively. The outer side of the first protrusion of the support portion serves to support the electrode body, and the first recess serves to accommodate the first tab on the electrode body. The electrolyte is easily injected into the receiving space from the end cap side through the injection hole. The projection of the injection hole along the thickness direction of the end cap overlaps with the projection of the first recess along the thickness direction of the end cap, allowing some of the electrolyte in the injection hole to fall directly into the first recess. This buffers some of the electrolyte in the injection hole and facilitates rapid accumulation of electrolyte in the first recess, allowing the electrolyte in the first recess to flow out more quickly from the first through hole, thereby achieving rapid electrolyte injection into the receiving space.

[0008] Secondly, embodiments of this application provide a battery pack including a plurality of battery cells as described in any embodiment;

[0009] The end cap is located below the corresponding housing, and the electrode body has a first end face facing the end cap. The ratio of the area of ​​the first through hole to the area of ​​the first end face is greater than or equal to 0.002 and less than or equal to 0.09. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0012] Figure 2 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0013] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0014] Figure 4 The diagram shows the structure of a single battery cell provided in some embodiments of this application.

[0015] in:

[0016] 1: Shell; 101: Opening;

[0017] 2: End cap; 201: Receiving space; 202: End cap body; 203: First insulating component; 204: Liquid injection hole;

[0018] 205: Second insulating component;

[0019] 3: Electrode assembly; 301: Electrode body; 302: First tab; 3011: First end face;

[0020] 4: Support member; 401: Support part; 402: Bearing part; 4011: First protrusion; 4012: First recess; 4013: First through hole;

[0021] 4015: First through hole;

[0022] 4018: Bottom wall; 4019: Peripheral wall;

[0023] X: First direction. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0026] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0029] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0030] As an example, a battery cell includes a cell formed by using positive and negative electrode plates as electrochemical material carriers, separating the positive and negative electrode plates through a separator to prevent short circuits, using an electrolyte as an ion transport carrier, providing structural protection through a casing, and connecting to an external circuit through terminals.

[0031] As an example, the battery cell includes at least one of the following: a square battery cell with a steel or aluminum casing, a plastic-cased battery, a pouch battery cell, or a cylindrical battery cell.

[0032] In some embodiments, the square aluminum-cased battery includes an end cap, on one end face of which a positive electrode post and a negative electrode post may be provided. A square aluminum shell is connected to the bottom of the end cap, and the edges of the square aluminum shell and the edge of the end cap are fitted together to form a receiving space. A positive electrode plate and a negative electrode plate are provided in the receiving space, and a separator paper is provided between the positive and negative electrode plates. The separator paper is mainly made of polyethylene.

[0033] In some embodiments, the separator paper is also referred to as Mylar membrane. The separator paper includes at least one or more thin films. When the separator paper includes multilayer composite films, the materials of each layer may be the same or different.

[0034] In some embodiments, the battery cell includes an isolation component excluding a separator paper. The isolation component includes a solid electrolyte disposed between the positive and negative electrodes. The solid electrolyte transports ions between the positive and negative electrodes and isolates the positive and negative electrodes.

[0035] In some embodiments, the square aluminum-cased battery is provided with a sealing ring, which is located between the square aluminum casing and the end cap, thereby achieving a seal between the square aluminum casing and the end cap.

[0036] In some embodiments, an insulating blue film is wrapped around the outside of the square aluminum casing to provide insulation protection for the square aluminum casing, thereby improving the reliability of the square aluminum casing battery.

[0037] In some embodiments, the active ions in the electrolyte include lithium ions, which move back and forth between the positive and negative electrode plates.

[0038] In some embodiments, the positive electrode sheet includes a positive current collector and a positive active material disposed on at least one surface of the positive current collector. The positive current collector has two surfaces perpendicular to its thickness direction, and the positive active material is disposed on at least one of the two opposing surfaces of the positive current collector.

[0039] In some embodiments, the positive electrode current collector includes either a metal foil or a composite current collector. When the positive electrode current collector is a metal foil, it includes at least one of the following: surface-plated aluminum, stainless steel, surface-plated stainless steel, aluminum, nickel, carbon electrode, carbon, nickel, or titanium. When the positive electrode current collector includes a composite current collector, it comprises a polymer material layer and a metal layer arranged sequentially. The polymer material layer includes, but is not limited to, substrates such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, and polyethylene; the metal layer includes, but is not limited to, metallic materials such as aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys.

[0040] In some embodiments, the negative electrode includes one of a metal foil and a negative current collector. When the negative electrode includes a metal foil, the metal foil includes, but is not limited to, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium. When the negative electrode includes a negative current collector, the negative current collector includes two surfaces perpendicular to its thickness direction, and at least one of the two surfaces is provided with a negative electrode active material.

[0041] As an example, the negative electrode active material includes at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. Silicon-based materials include at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials include at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0042] In some embodiments, when the battery cell includes a cylindrical battery cell, the cylindrical battery cell includes a cap, a housing, and a bottom spacer arranged sequentially. A sealing ring is provided between the cap and the housing, filling the gap between the cap and the housing. The cap, housing, and bottom spacer enclose a receiving space in which a wound bare battery cell is arranged. The bare battery cell includes a cathode electrode, an anode electrode, and a separator paper.

[0043] The bottom spacer has a negative electrode tab on the end face away from the accommodating space in the vertical thickness direction, and the outer shell is the negative end.

[0044] A positive terminal is provided on the end face of the cap on the side away from the receiving space in the vertical thickness direction, and a positive electrode tab is provided on the end face of the cap on the side closer to the receiving space in the vertical thickness direction. The positive electrode tab is located on the first end face of the positive electrode sheet, and the first end face is the end face perpendicular to the overlapping surface of several positive electrode sheets.

[0045] In some embodiments, the battery cell includes a pouch cell, which has a plurality of overlapping positive electrode plates, negative electrode plates, and separator paper inside. The pouch cell is enclosed by an aluminum-plastic packaging film and an insulating sheet to form a receiving space, which contains an electrolyte.

[0046] In some embodiments, battery cells are combined in series and parallel, fixed by an external frame, and connected to a battery management module with signal detection and a thermal management system for cooling to form a battery module.

[0047] In one example, the battery module includes a bottom plate for bottom protection, an end plate for end protection, a side plate for side protection, and a top cover for top protection.

[0048] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0049] The vehicle includes one of the following: gasoline-powered vehicles, natural gas-powered vehicles, or new energy vehicles. New energy vehicles include, but are not limited to, pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. A battery is located at the bottom, front, or rear of the vehicle. The battery powers the vehicle. As the vehicle's operating power source, the battery supplies power to the vehicle's electrical system, including meeting the power requirements for starting, navigation, and operation.

[0050] The vehicle also includes a controller and a motor. The controller is used to control the battery to power the motor, including meeting the power needs of the vehicle during startup, navigation, and driving.

[0051] In some embodiments of this application, the battery can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0052] The battery includes a housing and individual battery cells housed therein. The housing can have various structures. In some embodiments, the housing includes a first sub-housing and a second sub-housing, which are combined to form the housing. The first and second sub-housings together define a receiving space for accommodating the individual battery cells. The second sub-housing includes a square structural member with an opening on one side, and the first sub-housing includes a square structural member with an opening on one side. The openings of the first and second sub-housings are correspondingly combined so that the first and second sub-housings together define the receiving space. The first sub-housing includes a plate-like structural member, and the openings of the first and second sub-housings are closed on one side.

[0053] In a battery, there are multiple battery cells, which can be connected in series, parallel, or a combination thereof. A combination thereof means that multiple battery cells are connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, parallel, or a combination thereof, and then the entire assembly of these battery cells is housed within a casing. Alternatively, a battery can be composed of multiple battery cells first connected in series, parallel, or a combination thereof to form a battery module, and then these modules are connected in series, parallel, or a combination thereof to form a whole, which is also housed within a casing. The battery may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells.

[0054] The battery cell includes at least one of a secondary battery or a primary battery; the battery cell includes, but is not limited to, lithium-sulfur batteries, sodium-ion batteries or magnesium-ion batteries.

[0055] The development of battery technology involves many design factors, such as performance parameters like energy density and discharge energy. Furthermore, during battery manufacturing, testing, and debugging, batteries need to be clamped, moved, or transported. During this process, the internal electrode assembly inevitably moves with the battery. The electrode assembly includes electrode plates, separator paper, and tabs. When the battery is shaken, the electrode assembly vibrates, causing relative movement or collisions between the separator paper and electrode plates. When the battery is inverted, the tabs inevitably collide with the cover plate. Therefore, to protect the electrode plates and tabs, a support structure is provided for the electrode assembly. This support protects the tabs between the cover plate and the electrode plates and reduces or even prevents vibration of the electrode assembly.

[0056] The battery contains a housing space enclosed by a cover plate and a casing. A support member connects to the electrode assembly and is located within this housing space. Because the support member also needs to protect the electrode tabs, it is positioned between the electrode assembly and the cover plate. Furthermore, the support member obstructs one end face of the electrode assembly where the electrode tabs are located, causing a partial overlap between the projection of the support member in the thickness direction of the cover plate and the projection of the electrode assembly in the same direction. During battery electrolyte filling, the support member located between the electrode assembly and the cover plate obstructs the flow of electrolyte, reducing filling efficiency, especially as the first end face is difficult to wet until all electrolyte is injected, further impacting filling efficiency. The first end face can be the end face of the electrode assembly facing the cover plate.

[0057] Therefore, in order to improve the electrolyte injection efficiency of the battery, embodiments of this application provide a single battery cell, such as... Figure 1 As shown, the battery cell includes a housing 1, an end cap 2, an electrode assembly 3, and a support 4.

[0058] The housing 1 can be a conductive or insulating component, and the housing 1 can provide structural protection for the electrode assembly 3. The housing 1 has an opening 101.

[0059] End cap 2 seals the opening and is connected to housing 1 to define a receiving space 201, which contains electrode assembly 3 and electrolyte. During electrolyte injection, electrolyte enters the receiving space 201 from the outside of end cap 2 and gradually fills the receiving space 201, so that electrode assembly 3 inside the receiving space 201 is wetted by electrolyte.

[0060] The end cap 2 includes an end cap body 202 and a first insulating member 203. The first insulating member 203 achieves insulation isolation between the electrode assembly 3 and the end cap 2. During the liquid injection process, the first insulating member 203 will not affect the liquid injection process, thus improving the insulation safety of the liquid injection process.

[0061] The first insulating element 203 is disposed on the side of the end cap body 202 facing the receiving space 201; during liquid injection, the electrolyte flows from the end cap 2 to the first insulating element 203, and then flows to the support element 4 after passing through the first insulating element 203.

[0062] Electrode assembly 3 is disposed in receiving space 201. Electrode assembly 3 includes electrode body 301 and first tab 302. During the liquid injection process, the material not only wets the first tab 302, but also wets the electrode body 301.

[0063] It should be noted that the first electrode tab 302 can be either a positive electrode tab or a negative electrode tab, and this application does not limit it in this regard.

[0064] As an example, electrode assembly 3 is formed by stacking or winding a positive electrode, a negative electrode, and a separator. The separator is placed between the positive electrode and the negative electrode and serves as an insulator. The positive electrode and the negative electrode achieve ion conduction through the electrolyte.

[0065] The support member 4 is disposed between the electrode body 301 and the first insulating member 203. The support member 4 supports the electrode assembly 3, preventing the tabs from being pressed when the battery is inverted, and reducing the probability of the electrode assembly 3 falling off during shaking.

[0066] Support member 4 includes a support part 401 and a load-bearing part 402, please refer to Figure 2 and Figure 3 The support portion 401 protrudes relative to the bearing portion 402 toward the electrode body 301 to form a first protrusion 4011 and a first recess 4012 that are opposite to each other. When liquid is injected, the first recess 4012 can buffer and accumulate the injected material, thereby alleviating the problem of the electrolyte directly impacting the electrode assembly 3 during the liquid injection process.

[0067] The first through-hole 4013 is disposed on the first protrusion 4011. The electrolyte discharged from the first through-hole 4013 can flow along the surface of the first protrusion 4011, thereby the first protrusion 4011 can also provide secondary buffering for the injected material, preventing the injected material from falling directly onto the electrode assembly 3. The first protrusion 4011 guides the injected material, improving the injection efficiency. It should be noted that the first recess 4012 can also achieve the function of guiding the material in the injected solution to a certain extent.

[0068] The end cap 2 is provided with a liquid injection hole 204. Along the thickness direction of the end cap 2, the projection of the liquid injection hole 204 overlaps at least partially with the projection of the first recess 4012. The liquid injection hole 204 can be used to inject liquid into the battery. Because the projections of the liquid injection hole 204 and the first recess 4012 overlap at least partially in the thickness direction of the end cap 2, the material in the liquid injection flowing out of the liquid injection hole 204 will flow into the first recess 4012 in proportion to the overlapping area of ​​the projections. This allows the liquid injection material to accumulate in the first recess 4012 and will not directly impact the electrode assembly 3. The first recess 4012 enables the material to accumulate during the liquid injection process, thereby improving the liquid injection effect.

[0069] The first protrusion 4011 is also provided with a first through hole 4013 connecting the first recess 4012 and the receiving space 201. The first through hole 4013 enables the release of liquid material injected into the first recess 4012. When the material flows into the first recess 4012 during the liquid injection process, the first through hole 4013 releases the material accumulated in the first recess 4012 into the electrode assembly 3, thereby improving the wetting efficiency of the electrode assembly 3 and improving the liquid injection efficiency of the battery.

[0070] By providing a first through hole 4013 at the edge of the first protrusion 4011, the material in the first recess 4012 can be quickly discharged to the electrode assembly 3, thereby improving the wetting efficiency of the electrode assembly 3 and enabling the electrode assembly 3 to be quickly wetted.

[0071] In the battery cell proposed in this application embodiment, the support member 4 is located between the electrode body 301 and the first insulating member 203. The first insulating member 203 forms an insulating barrier between the support member 4 and the end cap body 202. The bearing part 402 supports the first insulating member 203, and the support part 401 is used to support the electrode body 301. Thus, the edge and center of the support member 4 support the first insulating member 203 and the electrode body 301 respectively.

[0072] The first protrusion 4011 of the support portion 401 serves to support the electrode body 301, and the first recess 4012 serves to accommodate the first tab 302 on the electrode body 301. The injection hole 204 facilitates the injection of material from one side of the end cap 2 into the receiving space 201. Furthermore, the projection of the injection hole 204 along the thickness direction of the end cap 2 partially overlaps with the projection of the first recess 4012 along the thickness direction of the end cap 2. This causes some of the material in the injection hole 204 to first fall into the first recess 4012, buffering some of the material passing through the injection hole 204, reducing the direct impact of the injected material on the electrode assembly 3, and improving the injection effect.

[0073] In other embodiments, please refer to Figure 2 The electrode body 301 has a first end face 3011 facing the end cap 2, and the area of ​​the first end face 3011 is greater than or equal to 2000 mm². 2 Less than or equal to 10000 mm 2 The area of ​​the first via 4013 is greater than or equal to 20mm. 2 Less than or equal to 200mm 2 The ratio of the area of ​​the first through hole 4013 to the area of ​​the first end face 3011 is greater than or equal to 0.002 and less than or equal to 0.1. When electrolyte is injected, the electrolyte enters through the injection hole 204, passes through the first insulating member 203 and the support member 4 in sequence, and then flows onto the first end face 3011. At this time, the electrolyte can start to wet the electrode assembly 3 from the first end face 3011, and then the electrolyte wets downward along the electrode assembly 3, thereby improving the wetting efficiency.

[0074] Understandably, the larger the ratio of the first through-hole 4013 to the first end face 3011, the faster the electrolyte in the first recess 4012 can flow to the first end face 3011. The smaller the ratio of the first through-hole 4013 to the first end face 3011, the smaller the impact of the first through-hole 4013 on the strength of the support member 4, ensuring that the support member 4 has sufficient strength to achieve the supporting effect.

[0075] In the above scheme, at this ratio, the time for the electrolyte to wet the first end face 3011 through the first through hole 4013 is further shortened, so that the electrolyte through the first through hole 4013 can wet the first end face 3011 in a faster time, so that the wetting time of the first end face 3011 does not change with its own area or the diameter of the first through hole 4013, thereby improving the wetting efficiency of the first end face 3011 of the electrode body 301 facing the end cover 2.

[0076] Optionally, the area of ​​the first end face 3011 can be 2000 mm². 2 3000mm 2 4000mm 2 5000mm 2 6000mm 2 7000mm 2 8000mm 2 9000mm 2 10000mm 2 It is understood that the above values ​​are merely examples of this application, and anything falling within the above range is within the protection scope of this application.

[0077] Optionally, the area of ​​the first via 4013 can be 20 mm. 2 40mm 2 60mm 2 80mm 2 100mm 2 120mm 2 140mm 2 160mm 2 180mm 2 200mm 2 It is understood that the above values ​​are merely examples of this application, and anything falling within the above range is within the protection scope of this application.

[0078] Optionally, the area ratio can be 0.002, 0.012, 0.022, 0.032, 0.042, 0.052, 0.062, 0.072, 0.082, 0.092, or 0.1. It is understood that the above values ​​are merely examples of this application, and anything falling within the above range is within the protection scope of this application.

[0079] In other embodiments, the solution further includes that the projection of the injection hole 204 does not coincide with the projection of the first through hole 4013 along the thickness direction of the end cap 2.

[0080] Therefore, during the electrolyte injection operation, after the electrolyte flows out of the injection hole 204, it will not fall directly into the first through hole 4013 under the action of gravity. Instead, it will first fall onto the inner wall of the first recess 4012 before passing through the first through hole 4013. This reduces the probability of the electrolyte flowing out of the injection hole 204 directly impacting the electrode assembly 3, allowing the electrolyte to be buffered by the inner wall of the first recess 4012, thus protecting the safety of the battery during the injection process.

[0081] In the above scheme, the electrolyte flowing out of the injection hole 204 will first flow onto the support member 4, so that the support member 4 can buffer the electrolyte flowing out of the injection hole 204, and then enter the first through hole 4013, reducing the probability that the electrolyte flowing out of the injection hole 204 will directly impact the electrode assembly 3.

[0082] In other embodiments, the solution further includes that, along the thickness direction of the end cap 2, the injection hole 204 has a first projection 2041, the first through hole 4013 has a second projection, and along the first direction X, the minimum distance between the first projection 2041 and the second projection is greater than or equal to 4 mm and less than or equal to 40 mm, and the first direction X is perpendicular to the thickness direction of the end cap 2.

[0083] The distance between the first projection 2041 and the second projection is the horizontal distance between the injection hole 204 and the first through hole 4013. By limiting the minimum distance mentioned above, the electrolyte flowing out of the injection hole 204 is horizontally displaced before entering the first through hole 4013, thus achieving a buffer between the electrolyte in the injection hole 204 and the first through hole 4013.

[0084] In the above scheme, at the minimum distance, the electrolyte flowing out of the injection hole 204 can enter the first through hole 4013 with a delay, so that there is a horizontal displacement between the electrolyte flowing out of the injection hole 204 and the electrolyte in the first through hole 4013.

[0085] Optionally, the minimum distance can be 4mm, 14mm, 24mm, 34mm, or 40mm. It is understood that the above values ​​are merely examples of this application, and anything falling within the above range is within the protection scope of this application.

[0086] On the one hand, it can ensure that the electrolyte in the first recess 4012 can be discharged from the first through hole 4013 relatively quickly, ensuring the wetting speed of the electrode assembly 3; on the other hand, the electrolyte can have sufficient time buffer in the first recess 4012 to reduce the impact energy of the electrolyte and further reduce the direct impact force of the electrolyte on the electrode assembly 3.

[0087] In some embodiments, this solution further includes a first through-hole 4013 comprising a plurality of spaced first sub-through-holes 4015, wherein the projection of the injection hole 204 does not coincide with the projection of any one of the first through-holes 4013 along the thickness direction of the end cap 2. After the electrolyte flows through the injection hole 204 to the first recess 4012, it is discharged through several first sub-through-holes 4015 to wet the electrode assembly 3. At this time, the electrolyte first flows into the first recess 4012, and then flows out sequentially from the nearest and farthest first sub-through-holes 4015. Along the thickness direction of the end cap 2, the distance between the projection of the injection hole 204 and the projection of any one of the first sub-through-holes 4015 is compared. The first sub-through-hole 4015 corresponding to the smaller distance is the nearest first sub-through-hole 4015, and the first sub-through-hole 4015 corresponding to the larger distance is the farthest first sub-through-hole 4015.

[0088] In the above scheme, the electrode assembly 3 is simultaneously wetted from multiple directions through multiple first sub-vias 4015, and the electrolyte flowing out of the injection hole 204 will not directly enter any of the first sub-vias 4015, thereby achieving rapid liquid injection into the accommodating space 201 while reducing the impact force of the electrolyte on the electrode assembly 3.

[0089] After the electrolyte in the injection hole 204 falls into the first recess 4012, the impact point of the electrolyte in the first recess 4012 can be located between several first sub-through holes 4015, and then flows to each first sub-through hole 4015. Electrolysis simultaneously wets the electrode assembly 3 through multiple first sub-through holes 4015, so that the electrode assembly 3 can obtain electrolyte at different positions, thereby achieving wetting from multiple positions and improving wetting efficiency.

[0090] In other embodiments, this solution further includes, along the thickness direction of the end cap 2, the projections of the plurality of first sub-vias 4015 include a third projection and a fourth projection. Along the first direction X, the third and fourth projections are located on either side of the projection of the injection hole 204, and the first direction X is perpendicular to the thickness direction of the end cap 2. After the electrolyte in the injection hole 204 flows into the first recess 4012, the electrolyte can flow to the first sub-via 4015 corresponding to the third projection and the first sub-via 4015 corresponding to the fourth projection, respectively, so that the electrolyte can flow to the first sub-vias 4015 in different directions along different paths.

[0091] When the distances between the third and fourth projections and the projections of the injection hole 204 are the same, the electrolyte in the injection hole 204 can simultaneously flow out from the first sub-vias 4015 corresponding to the third and fourth projections. At this time, the electrode assembly 3 can simultaneously obtain electrolyte injection from the first sub-vias 4015 in two different directions. When the distances between the third and fourth projections and the projections of the injection hole 204 are different, the electrolyte in the injection hole 204 can sequentially flow out from the first sub-vias 4015 corresponding to the third and fourth projections. At this time, the electrode assembly 3 can sequentially obtain the wetting of the electrolyte discharged from the first sub-vias 4015 corresponding to the third and fourth projections.

[0092] When the third and fourth projections are located on both sides of the injection hole 204, the first sub-vias 4015 corresponding to the third and fourth projections are located on both sides of the injection hole 204. At this time, when the electrolyte flows out of the injection hole 204, the electrolyte can enter the first sub-vias 4015 corresponding to the third and fourth projections after flowing to both sides, ensuring that the electrode assembly 3 can be wetted by electrolyte from different directions, thus improving the injection efficiency and wetting effect.

[0093] In other embodiments, this solution further includes a first through-hole 4013 that is an elongated hole, wherein the dimension of the first through-hole 4013 in the length direction of the end cap 2 is greater than the dimension of the first through-hole 4013 in the width direction of the end cap 2. When the electrolyte flows to the first through-hole 4013, the electrolyte flows out along the elongated hole. Since the dimension of the first through-hole 4013 in the length direction of the end cap 2 is greater than the dimension of the first through-hole 4013 in the width direction of the end cap 2, the length and width of the elongated hole correspond to the length and width of the end cap 2, respectively. At this time, when the electrolyte flows out from the longer side of the elongated hole, it can wet the corresponding long side of the end cap 2 of the electrode assembly 3, and when the electrolyte flows out from the shorter side of the elongated hole, it can wet the corresponding short side of the end cap 2 of the electrode assembly 3.

[0094] In other words, the elongated first through-hole 4013 is designed according to the shape of the electrode assembly 3, so as to maximize the efficiency of wetting the electrode assembly 3 and improve the overall wetting effect of the electrode assembly 3.

[0095] In the above scheme, the elongated first through-hole 4013 allows the electrolyte to flow out more quickly, enabling faster injection along the length of the end cap 2. This results in a higher injection efficiency along the length of the end cap 2 compared to the width. Since the length of the electrode assembly 3 aligns with the length of the end cap 2, the longer side of the electrode assembly 3 can be wetted more quickly, reducing the likelihood of the wider side of the electrode assembly 3 being fully wetted while the longer side remains unwetted or only partially wetted. This improves the overall wetting efficiency and effect of the electrode assembly 3.

[0096] In other embodiments, such as Figure 4 As shown, this solution also includes a first protrusion 4011 comprising a bottom wall 4018 and a peripheral wall 4019. Along the thickness direction of the end cap 2, the bottom wall 4018 abuts against the electrode body 301, one end of the peripheral wall 4019 is connected to the outer periphery of the bottom wall 4018, and the other end of the peripheral wall 4019 is connected to the support portion 402.

[0097] In other words, the bottom wall 4018 and the peripheral wall 4019 form a first recess 4012 for temporarily containing electrolyte. After the electrolyte flows out from the injection hole 204, it enters the first recess 4012. The electrode body 301 is supported by the bottom wall 4018, and the bottom wall 4018 is supported by the bearing part 402 through the peripheral wall 4019.

[0098] In the above scheme, the bottom wall 4018 of the first protrusion 4011 abuts against the electrode body 301, and the peripheral wall 4019 connects the bottom wall 4018 and the support part 402. The peripheral wall 4019 provides support for the bottom wall 4018 and the support part 402 on the side of the bottom wall 4018. The peripheral wall 4019 can guide the electrolyte to the bottom wall 4018, improving the electrolyte injection efficiency.

[0099] In some embodiments, this solution further includes a first through-hole 4013 disposed on the bottom wall 4018. This allows the electrolyte to flow directly out from the first through-hole 4013 on the bottom wall 4018. Since the bottom wall 4018 also supports the electrode body 301, the electrolyte can flow directly from the first through-hole 4013 onto the electrode body 301. This avoids direct impact of the electrolyte on the electrode assembly 3 while also increasing the speed and efficiency of the electrolyte flowing out from the first through-hole 4013. This achieves wetting of the electrode assembly 3, improving wetting efficiency and effect.

[0100] In the above scheme, when the electrolyte flows out from the first through hole 4013, it can flow directly onto the electrode body 301, which improves the wetting efficiency and wetting effect, and realizes rapid wetting of the electrode body 301 and the corresponding side of the support 4.

[0101] In other embodiments, this solution further includes a first through-hole 4013 disposed on the peripheral wall 4019. This ensures that the electrolyte can only be wetted through the first through-hole 4013 when the height reaches the first through-hole 4013 on the peripheral wall 4019. At this time, after a certain amount of electrolyte is stored in the first recess 4012, it flows out from the first through-hole 4013 located on the peripheral wall 4019, thereby further enhancing the buffering effect of the support portion 401.

[0102] In addition, in the above scheme, the electrolyte can be discharged from the first through hole 4013 during the injection process and then guided to the electrode assembly 3 along the peripheral wall 4019. The process of the electrolyte flowing on the peripheral wall 4019 is also another kind of buffering process. That is, when the electrolyte flows out of the first through hole 4013, it can be buffered by the side of the peripheral wall 4019.

[0103] In other embodiments, this solution further includes a minimum distance A between the first through hole 4013 and the bottom wall 4018 along the thickness direction of the end cap 2, satisfying 0 ≤ A ≤ 5 mm. Optionally, the minimum distance between the first through hole 4013 and the bottom wall 4018 can be 0, 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm. It is understood that the above values ​​are merely examples of this application, and anything falling within the above range is within the protection scope of this application.

[0104] When the electrolyte flows to the bottom wall 4018, it accumulates in the first recess 4012. After the electrolyte flows out from the first through hole 4013, it can wet the electrode assembly 3. Since the minimum distance between the first through hole 4013 and the bottom wall 4018 along the thickness direction of the end cap 2 meets the above range, on the one hand, it can ensure that the support part 401 can store a certain amount of electrolyte and ensure the buffering capacity of the support part 401 for the electrolyte. On the other hand, it will not have too much negative impact on the wetting speed of the electrode assembly 3 due to the storage of too much electrolyte in the first recess 4012.

[0105] In the above scheme, the electrolyte accumulates a certain amount on the bottom wall 4018 and then flows out through the first through hole 4013, which shortens the buffer time of the electrolyte on the bottom wall 4018 and improves the injection efficiency.

[0106] In other embodiments, this solution further includes an inner edge of the cross-section of the peripheral wall 4019 along the first direction X, which is inclined relative to the inner side of the bottom wall 4018, and the first direction X is perpendicular to the thickness direction of the end cap 2. The inclined peripheral wall 4019 allows the electrolyte in the first recess 4012 to drain more quickly from the first through hole 4013, thereby improving the wetting efficiency of the electrolyte on the electrode assembly 3. In addition, when the inclined peripheral wall 4019 is opposite the injection hole 204 in the thickness direction of the end cap 2, it can better buffer the electrolyte and reduce the impact energy of the electrolyte.

[0107] In the above scheme, after the electrolyte is discharged from the first through hole 4013, the inclined peripheral wall 4019 plays a role in guiding the electrolyte, so that the electrolyte on the peripheral wall 4019 flows more slowly to the electrode assembly 3, thereby better buffering the electrolyte and improving the wetting effect of the electrode assembly 3.

[0108] In other embodiments, the present solution further includes that, along the first direction X, the angle between the inner edge of the cross section of the peripheral wall 4019 in the first direction X and the inner surface of the bottom wall 4018 is θ, satisfying 91°≤θ≤179°.

[0109] Since the angle between the inner edge of the cross section of the peripheral wall 4019 in the first direction X and the inner side surface of the bottom wall 4018 satisfies the above-mentioned range, the inclined peripheral wall 4019 allows the electrolyte in the first recess 4012 to be discharged from the first through hole 4013 more quickly, thereby improving the wetting efficiency of the electrolyte on the electrode assembly 3. In addition, when the inclined peripheral wall 4019 is opposite to the injection hole 204 in the thickness direction of the end cap 2, it can better buffer the electrolyte and reduce the impact energy of the electrolyte.

[0110] Optionally, the angle θ between the inner edge of the cross-section of the peripheral wall 4019 in the first direction X and the inner surface of the bottom wall 4018 can be 91°, 101°, 111°, 121°, 131°, 141°, 151°, 161°, 171°, or 179°. It is understood that the above values ​​are merely examples of this application, and anything falling within the above range is within the protection scope of this application.

[0111] On the one hand, the inclined peripheral wall 4019 can further enhance the buffering effect on the electrolyte, and on the other hand, it can prevent the peripheral wall 4019 from being too inclined and affecting the supporting function of the support member 4.

[0112] In some other embodiments, the present solution further includes an electrode body 301 having a first end face 3011 facing the end cap 2, wherein the ratio of the area of ​​the first through hole 4013 to the area of ​​the first end face 3011 is greater than or equal to 0.003 and less than or equal to 0.1.

[0113] When the electrolyte passes through the first through hole 4013, the area of ​​the first through hole 4013 affects the injection rate of the electrolyte. By setting the area ratio, the electrolyte passing through the first through hole 4013 can quickly wet the electrode assembly 3, while also ensuring the buffering effect of the support 4 on the electrolyte.

[0114] Optionally, the ratio of the area of ​​the first via 4013 to the area of ​​the first end face 3011 can be 0.003, 0.013, 0.023, 0.033, 0.043, 0.053, 0.063, 0.073, 0.083, 0.093, or 0.1. It is understood that the above values ​​are merely examples of this application, and any values ​​falling within the above range are within the protection scope of this application.

[0115] In the above scheme, when the ratio of the area of ​​the first through hole 4013 to the area of ​​the first end face 3011 is 0.003 or 0.1, the electrolyte flows out of the first through hole 4013 faster and wets the first end face 3011 faster, thereby improving the injection efficiency and ensuring the buffering effect of the support member 4 on the electrolyte.

[0116] In other embodiments, this solution further includes ensuring that the projection of the first tab 302 at least partially overlaps with the projection of the injection hole 204 along the thickness direction of the end cap 2. After the electrolyte flows out of the injection hole 204, it first impacts the first tab 302, which can buffer part of the electrolyte, before entering the first recess 4012. Furthermore, by partially overlapping the projection of the first tab 302 with the projection of the injection hole 204, the first tab 302 is completely contained within the first recess 4012.

[0117] In the above scheme, part of the electrolyte flowing out of the injection hole 204 will be blocked by the first tab 302. That is to say, part of the electrolyte flowing out of the injection hole 204 can fall directly into the first recess 4012, and the other part is buffered by the tab and flows along the first tab 302 to the first recess 4012.

[0118] In other embodiments, the present solution further includes that at least one side of the first tab 302 in the thickness direction is provided with a second insulating member 205, and one end of the second insulating member 205 extends beyond the same side end of the first tab 302 along the width direction of the first tab 302.

[0119] The second insulating element 205 provides insulation and isolation for the first electrode 302 along the width direction of the first electrode 302. At the same time, since at least a portion of the first electrode 302 is covered by the second insulating element 205, it plays a buffering role during the bending process of the first electrode 302, reducing the probability of breakage due to excessive bending of the first electrode 302.

[0120] In other embodiments, the present solution further includes that the area of ​​the injection hole 204 is greater than or equal to 2 mm. 2 Less than or equal to 20mm 2 The ratio of the area of ​​the first through-hole 4013 to the area of ​​the first end face 3011 is greater than or equal to 0.004 and less than or equal to 0.1. The injection efficiency of the injection hole 204 is affected by the ratio of the area of ​​the first through-hole 4013 to the area of ​​the first end face 3011. Since the ratio of the area of ​​the first through-hole 4013 to the area of ​​the first end face 3011 meets the above range, on the one hand, the injection efficiency during the injection process is guaranteed, ensuring that the electrode assembly 3 can be wetted at a suitable speed; on the other hand, it also ensures that the support member 4 can buffer the electrolyte, reducing the probability of the electrolyte directly impacting the electrode assembly 3.

[0121] In the above scheme, by limiting the area of ​​the injection hole 204, the injection speed of the injection hole 204 can be accelerated, so that the optimal injection rate is maintained when the areas of the first through hole 4013 and the first end face 3011 change. This also improves the matching degree between the electrolyte input flow rate and the electrode body 301 and the first through hole 4013.

[0122] Optionally, the area of ​​the injection hole 204 can be 2 mm². 2 4mm 2 6mm 2 8mm 2 10mm 2 14mm 2 16mm 2 18mm 2 20mm 2 It is understood that the above values ​​are merely examples of this application, and anything falling within the above range is within the protection scope of this application.

[0123] Optionally, the ratio of the area of ​​the first via 4013 to the area of ​​the first end face 3011 can be 0.004, 0.014, 0.024, 0.034, 0.044, 0.054, 0.064, 0.074, 0.084, 0.094, or 0.1. It is understood that the above values ​​are merely examples of this application, and any values ​​falling within the above range are within the protection scope of this application.

[0124] In other embodiments, this solution further includes a single electrode body 301, wherein the ratio of the area of ​​the first via 4013 to the area of ​​the first end face 3011 is greater than or equal to 0.001 and less than or equal to 0.05. After passing through the first via 4013, the electrolyte wets the first end face 3011 proportionally according to the area ratio, thereby improving the wetting efficiency and effect of the first end face 3011.

[0125] The above solution improves the liquid injection efficiency and effect of the battery cell, including an electrode body 301. It ensures that both good liquid injection speed and effect can be achieved simultaneously.

[0126] Optionally, the ratio of the area of ​​the first via 4013 to the sum of the areas of the plurality of first end faces 3011 can be 0.001, 0.011, 0.021, 0.031, 0.041, or 0.05. It is understood that the above values ​​are merely examples of this application, and any values ​​falling within the above range are within the protection scope of this application.

[0127] The present invention also provides another embodiment in which the number of electrode bodies 301 is plurality of, and the ratio of the area of ​​the first through-hole 4013 to the sum of the areas of the plurality of first end faces 3011 is greater than or equal to 0.001 and less than or equal to 0.05. After passing through the first through-hole 4013, the electrolyte can wet the plurality of electrode bodies 301. Furthermore, because the ratio of the area of ​​the first through-hole 4013 to the sum of the areas of the plurality of first end faces 3011 is [value missing], the electrolyte injection efficiency increases with the increase in the number of electrode bodies 301, ensuring that the plurality of electrode assemblies 3 can also be wetted efficiently.

[0128] The above solution improves the liquid injection efficiency when there are multiple electrode bodies 301, and can improve the liquid injection efficiency and wetting effect without being limited by the number of electrode bodies 301.

[0129] Optionally, the ratio of the area of ​​the first via 4013 to the sum of the areas of the plurality of first end faces 3011 can be 0.001, 0.011, 0.021, 0.031, 0.041, or 0.05. It is understood that the above values ​​are merely examples of this application, and any values ​​falling within the above range are within the protection scope of this application.

[0130] The present invention also provides another embodiment in which the electrode assembly 3 is a wound electrode assembly 3, and the ratio of the area of ​​the first through hole 4013 to the area of ​​the first end face 3011 is greater than or equal to 0.003 and less than or equal to 0.09. The electrolyte can simultaneously wet the anode, cathode, and the shielded portion of the connected diaphragm of the wound electrode, and can simultaneously wet multiple portions of any anode, cathode, or diaphragm, improving the electrolyte injection efficiency of the wound electrode assembly 3. At this area ratio, the wetting efficiency of any anode, cathode, or diaphragm in the first end face 3011 of the wound electrode assembly 3 is improved.

[0131] In the above scheme, the electrode assembly 3 includes a wound electrode assembly 3. The electrolyte that enters the receiving space 201 through the injection hole 204 first flows to the first end face 3011 corresponding to the anode, cathode and the diaphragm connected in the wound electrode assembly 3. The ratio of the area of ​​the first through hole 4013 to the area of ​​the first end face 3011 can improve the wetting efficiency of the anode, cathode and the diaphragm connected therein, improve the injection efficiency of the wound electrode assembly 3, and at the same time ensure the wetting effect of the electrode assembly 3.

[0132] Optionally, the ratio of the area of ​​the first via 4013 to the area of ​​the first end face 3011 can be: 0.003, 0.013, 0.023, 0.033, 0.043, 0.053, 0.063, 0.073, 0.083, or 0.09. It is understood that the above values ​​are merely examples of this application, and any values ​​falling within the above range are within the protection scope of this application.

[0133] The present invention also provides another embodiment in which the electrode assembly 3 is a stacked electrode assembly 3, and the ratio of the area of ​​the first through-hole 4013 to the area of ​​the first end face 3011 is greater than or equal to 0.004 and less than or equal to 0.1. The electrolyte simultaneously wets the multiple layers of positive electrode, negative electrode, and separator paper of the stacked electrode assembly 3, ensuring that the parts of each layer that are blocked are quickly wetted, thereby improving the wetting efficiency of the stacked electrode assembly 3. At this ratio, the first end face 3011 corresponding to the stacked electrode assembly 3 can be wetted more quickly, and the wetting effect of the electrode assembly 3 can also be guaranteed.

[0134] In the above scheme, the electrode assembly 3 includes a stacked electrode assembly 3. After entering the receiving space 201 through the injection hole 204, the liquid first flows to the first end face 3011 corresponding to the tab of the stacked electrode assembly 3. The wettability of the electrode body 301 is improved by the ratio of the area of ​​the first through hole 4013 to the area of ​​the first end face 3011, thereby improving the injection efficiency of the stacked electrode assembly 3.

[0135] Optionally, the ratio of the area of ​​the first via 4013 to the area of ​​the first end face 3011 can be 0.004, 0.014, 0.024, 0.034, 0.044, 0.054, 0.064, 0.074, 0.084, 0.094, or 0.1. It is understood that the above values ​​are merely examples of this application, and any values ​​falling within the above range are within the protection scope of this application.

[0136] The present invention also provides another embodiment, in which a battery cell is included, the battery cell including an end cap 2, the end cap 2 being connected to a housing 1, the end cap 2 and the housing 1 together enclosing a receiving space 201. The end cap 2 includes an end cap body 202 and a first insulating member 203 arranged sequentially toward the interior of the receiving space 201.

[0137] An electrode assembly 3 is provided in the accommodating space 201. A support member 4 is provided between the electrode assembly 3 and the first insulating member 203. The support member 4 has an electrode tab accommodating area on the side near the first insulating member 203. The projection of the electrode tab accommodating area along the thickness direction of the end cap 2 at least partially overlaps with the liquid injection hole 204. A first recess 4012 is provided in the middle of the support member 4. The first recess 4012 includes a bottom wall 4018 and a peripheral wall 4019. The first recess 4012 and the first insulating member 203 form the electrode tab accommodating area. A first through hole 4013 is provided in the peripheral wall 4019. The area ratio of the first through hole 4013 to the end face of the electrode assembly 3 near the end cap 2 is greater than or equal to 0.002 and less than or equal to 0.09.

[0138] The first through-hole 4013 includes at least two, and the projections of the multiple first through-holes 4013 along the thickness direction of the end cap 2 do not coincide with the liquid injection hole 204 on the end cap 2, and the liquid injection hole 204 is located between the projections of the multiple first through-holes 4013. The positional distance between the projection of the first through-hole 4013 along the thickness direction of the end cap 2 and the liquid injection hole 204 on the end cap 2 is greater than or equal to 4 mm and less than or equal to 40 mm.

[0139] The first through hole 4013 has a larger dimension in the length direction of the end cap 2 than its dimension in the width direction of the end cap 2.

[0140] The bottom wall 4018 abuts against the electrode assembly 3, and the peripheral wall 4019 is located on both sides of the electrode assembly 3. Along the thickness direction of the end cap 2, the minimum distance between the first through hole 4013 and the bottom wall 4018 is A, satisfying 0 ≤ A ≤ 5 mm. Along the first direction X, the inner edge of the cross-section of the peripheral wall 4019 in the first direction X is inclined relative to the inner surface of the bottom wall 4018, and the first direction X is perpendicular to the thickness direction of the end cap 2. Along the first direction X, the angle between the inner edge of the cross-section of the peripheral wall 4019 in the first direction X and the inner surface of the bottom wall 4018 is θ, satisfying 91° ≤ θ ≤ 179°.

[0141] The electrode assembly 3 includes a first tab 302 located in the tab receiving area. Along the thickness direction of the end cap 2, the projection of the first tab 302 at least partially overlaps with the projection of the injection hole 204.

[0142] The first electrode tab 302 has a second insulating member 205 on at least one side in the thickness direction. Along the width direction of the first electrode tab 302, one end of the second insulating member 205 extends beyond the same side end of the first electrode tab 302. The surface of the first electrode tab 302 is covered with an insulating adhesive layer, the width of which exceeds the width of the first electrode tab 302.

[0143] The area of ​​injection hole 204 is greater than or equal to 2 mm². 2 Less than or equal to 20mm 2 The ratio of the area of ​​the first via 4013 to the area of ​​the first end face 3011 is greater than or equal to 0.004 and less than or equal to 0.1.

[0144] The electrode assembly 3 includes multiple electrodes, and the ratio of the area of ​​the end face of the electrode assembly 3 near the end cap 2 to the opening area of ​​the first through hole 4013 is greater than or equal to 0.001 and less than or equal to 0.05.

[0145] In other embodiments, this application discloses a battery pack including a plurality of battery cells as described in any of the above embodiments, with an end cap located below the corresponding housing, an electrode body having a first end face facing the end cap, and the ratio of the area of ​​the first through hole to the area of ​​the first end face being greater than or equal to 0.002 and less than or equal to 0.09.

[0146] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0147] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0148] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0149] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, include: The casing has an opening; An end cap is provided to seal the opening. The end cap is connected to the housing to form a receiving space. The end cap includes an end cap body and a first insulating member. The first insulating member is disposed on the side of the end cap body facing the receiving space. An electrode assembly is disposed in the receiving space, the electrode assembly including an electrode body and a first electrode tab; A support member is disposed between the electrode body and the first insulating member. The support member includes a support portion and a bearing portion. The support portion protrudes relative to the bearing portion in the direction toward the electrode body to form a first protrusion and a first recess that are opposite to each other. The end cap is provided with a liquid injection hole, and the projection of the liquid injection hole at least partially overlaps with the projection of the first recess along the thickness direction of the end cap. The first protrusion is also provided with a first through hole connecting the first recess and the receiving space.

2. The battery cell according to claim 1, characterized in that, The electrode body has a first end face facing the end cap, and the ratio of the area of ​​the first through hole to the area of ​​the first end face is greater than or equal to 0.002 and less than or equal to 0.

1.

3. The battery cell according to claim 1, characterized in that, Along the thickness direction of the end cap, the projection of the injection hole does not coincide with the projection of the first through hole.

4. The battery cell according to claim 3, characterized in that, Along the thickness direction of the end cap, the injection hole has a first projection, the first through hole has a second projection, and along the first direction, the minimum distance between the first projection and the second projection is greater than or equal to 4 mm and less than or equal to 40 mm. The first direction is perpendicular to the thickness direction of the end cap.

5. The battery cell according to claim 3, characterized in that, The first through hole includes a plurality of first sub-through holes spaced apart. Along the thickness direction of the end cap, the projection of the injection hole does not coincide with the projection of any one of the first through holes.

6. The battery cell according to claim 5, characterized in that, Along the thickness direction of the end cap, the projections of the plurality of first sub-through holes include a third projection and a fourth projection. Along a first direction, the third projection and the fourth projection are located on both sides of the projection of the injection hole. The first direction is perpendicular to the thickness direction of the end cap.

7. The battery cell according to claim 1, characterized in that, The first through hole is an elongated hole, and the dimension of the first through hole in the length direction of the end cap is greater than the dimension of the first through hole in the width direction of the end cap.

8. The battery cell according to claim 1, characterized in that, The first protrusion includes a bottom wall and a peripheral wall. Along the thickness direction of the end cap, the bottom wall abuts against the electrode body, one end of the peripheral wall is connected to the outer periphery of the bottom wall, and the other end of the peripheral wall is connected to the support portion.

9. The battery cell according to claim 8, characterized in that, The first through hole is disposed on the bottom wall.

10. The battery cell according to claim 8, characterized in that, The first through hole is disposed on the peripheral wall.

11. The battery cell according to claim 10, characterized in that, Along the thickness direction of the end cap, the minimum distance between the first through hole and the bottom wall is A, which satisfies 0≤A≤5mm.

12. The battery cell according to claim 10, characterized in that, Along a first direction, the inner edge of the cross-section of the peripheral wall in the first direction is inclined relative to the inner side surface of the bottom wall, and the first direction is perpendicular to the thickness direction of the end cap.

13. The battery cell according to claim 12, characterized in that, Along the first direction, the angle between the inner edge of the cross section of the peripheral wall in the first direction and the inner surface of the bottom wall is θ, which satisfies 91°≤θ≤179°.

14. The battery cell according to claim 10, characterized in that, The electrode body has a first end face facing the end cap, and the ratio of the area of ​​the first through hole to the area of ​​the first end face is greater than or equal to 0.003 and less than or equal to 0.

1.

15. The battery cell according to claim 1, characterized in that, Along the thickness direction of the end cap, the projection of the first electrode ear at least partially overlaps with the projection of the injection hole.

16. The battery cell according to claim 1, characterized in that, The first electrode tab has a second insulating member on at least one side in the thickness direction, and one end of the second insulating member extends beyond the same side end of the first electrode tab along the width direction.

17. The battery cell according to claim 2, characterized in that, The area of ​​the injection hole is greater than or equal to 2 mm². 2 Less than or equal to 20mm 2 The ratio of the area of ​​the first via to the area of ​​the first end face is greater than or equal to 0.004 and less than or equal to 0.

1.

18. The battery cell according to claim 2, characterized in that, The number of electrode bodies is one, and the ratio of the area of ​​the first via to the area of ​​the first end face is greater than or equal to 0.001 and less than or equal to 0.

05.

19. The battery cell according to claim 2, characterized in that, The number of electrode bodies is multiple, and the ratio of the area of ​​the first via to the sum of the areas of the multiple first end faces is greater than or equal to 0.001 and less than or equal to 0.

05.

20. The battery cell according to claim 2, characterized in that, The electrode assembly is a wound electrode assembly, and the ratio of the area of ​​the first through hole to the area of ​​the first end face is greater than or equal to 0.003 and less than or equal to 0.

09.

21. The battery cell according to claim 2, characterized in that, The electrode assembly is a stacked electrode assembly, and the ratio of the area of ​​the first via to the area of ​​the first end face is greater than or equal to 0.004 and less than or equal to 0.

1.

22. A battery pack, characterized in that, The device includes multiple battery cells as described in any one of claims 1-21, wherein the end cap is located below the corresponding housing, the electrode body has a first end face facing the end cap, and the ratio of the area of ​​the first through hole to the area of ​​the first end face is greater than or equal to 0.002 and less than or equal to 0.09.

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