Battery cell, end cover assembly, battery, electric device and energy storage device

Abstract

Provided in the embodiments of the present application are a battery cell, an end cover assembly, a battery, an electric device and an energy storage device, which can improve the use performance of the battery. The battery cell comprises: an electrode assembly, an electrode terminal assembly, and a first wall, wherein the first wall comprises a through hole, the through hole penetrating the first wall in the direction of thickness of the first wall; the electrode terminal assembly is sealingly connected to the first wall, and the electrode terminal assembly is electrically connected to the electrode assembly through the through hole; and the first wall further comprises a buffer portion, which is arranged around the periphery of the electrode terminal assembly, the thickness of the buffer portion being less than the thickness of the part of the first wall other than the buffer portion.

Description

Battery cell, end cover assembly, battery, electric device and energy storage device

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 202410741316.X, filed on June 7, 2024, entitled “Battery cell, end cover assembly, battery, electric device and energy storage device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, and more particularly, to a battery cell, an end cover assembly, a battery, an electric device and an energy storage device. BACKGROUND

[0004] With the increasing environmental pollution, new energy industry is attracting more and more attention. In the new energy industry, battery technology is an important factor for its development. In the development of battery technology, in addition to improving the electrical performance of the battery, safety is also an issue that cannot be ignored. If the safety of the battery cannot be guaranteed, the battery cannot be used, reducing the use performance of the battery.

[0005] Therefore, how to improve the use performance of the battery has become a technical problem to be solved in the art.

[0006] SUMMARY

[0007] The embodiments of the present application provide a battery cell, an end cover assembly, a battery, an electric device and an energy storage device, which can improve the use performance of the battery.

[0008] In a first aspect, a battery cell is provided, comprising: an electrode assembly; an electrode terminal assembly; a first wall comprising a through hole penetrating through the first wall along a thickness direction of the first wall, the electrode terminal assembly being sealingly connected with the first wall, and the electrode terminal assembly being electrically connected with the electrode assembly through the through hole; the first wall further comprising a buffer portion, the buffer portion being arranged around an outer periphery of the electrode terminal assembly, a thickness of the buffer portion being less than a thickness of a portion of the first wall other than the buffer portion.

[0009] In the embodiments of the present application, by arranging the buffer portion on the first wall of the battery monomer, the buffer portion is arranged around the outer periphery of the electrode terminal assembly arranged on the first wall in the battery monomer, the thickness of the buffer portion is less than the thickness of the part of the first wall other than the buffer portion, in the case that the battery monomer is subjected to impact, vibration or other loads, the buffer portion can play a role of buffering and absorbing the impact, so as to reduce the deformation or non-deformation of the connection area between the electrode terminal assembly and the first wall, thereby reducing the risk of sealing failure caused by the existence of a large gap between the electrode terminal assembly and the first wall, improving the sealing performance of the battery monomer, and further improving the use performance of the battery.

[0010] In some implementations, the minimum thickness of the buffer portion is greater than the thickness of the shell of the battery monomer, and the maximum thickness of the buffer portion is less than the first thickness, the first thickness being the minimum thickness of the part of the first wall that is sealingly connected with the electrode terminal assembly.

[0011] In the embodiments of the present application, by arranging the buffer portion on the first wall of the battery monomer, the buffer portion is arranged around the outer periphery of the electrode terminal assembly arranged on the first wall in the battery monomer, the thickness of the buffer portion is less than the thickness of the part of the first wall other than the buffer portion, in the case that the battery monomer is subjected to impact, vibration or other loads, the buffer portion can play a role of buffering and absorbing the impact, so as to reduce the deformation or non-deformation of the connection area between the electrode terminal assembly and the first wall, thereby reducing the risk of sealing failure caused by the existence of a large gap between the electrode terminal assembly and the first wall, improving the sealing performance of the battery monomer, and further improving the use performance of the battery.

[0012] In some implementations, in the thickness direction perpendicular to the first wall, the minimum distance L1 between the side of the electrode terminal assembly close to the buffer portion and the outer wall of the buffer portion close to the electrode terminal assembly is greater than or equal to 0.5 mm.

[0013] In the embodiments of the present application, in the thickness direction perpendicular to the first wall, by arranging the distance L1 between the side of the electrode terminal assembly close to the buffer portion and the outer wall of the buffer portion close to the electrode terminal assembly to be greater than or equal to 0.5 mm, the damage of the buffer portion in the process of welding connection between the electrode terminal assembly and the first wall is reduced, the influence on the use performance of the buffer portion is reduced, thereby improving the sealing performance of the battery monomer in the case that the battery monomer is subjected to impact, vibration or other loads, and improving the use performance of the battery.

[0014] In some implementations, in the thickness direction perpendicular to the first wall, the minimum distance L1 between the side of the electrode terminal assembly close to the buffer portion and the outer wall of the buffer portion close to the electrode terminal assembly is: 0.5 mm≤L1≤2 mm.

[0015] In the embodiment of the present application, in the thickness direction perpendicular to the first wall, the distance L1 between the side of the electrode terminal assembly close to the buffer portion and the outer wall of the buffer portion close to the electrode terminal assembly is set to 0.5mm≤L1≤2mm, so as to effectively improve the buffering and absorption effect of the buffer portion on external impact in the case that the battery monomer is subjected to impact, vibration or other loads, and reduce the influence of the electrode terminal assembly and the first wall on the buffer portion during welding, thereby effectively reducing the risk of sealing failure between the electrode terminal assembly and the first wall, improving the sealing performance of the battery monomer, and further improving the use performance of the battery.

[0016] In some implementations, the buffer portion protrudes away from the electrode assembly, and / or the buffer portion protrudes towards the electrode assembly. In this way, in the embodiment of the present application, by setting the buffer portion to protrude away from the electrode assembly of the battery monomer, and / or setting the buffer portion to protrude towards the electrode assembly, the protruding structure of the buffer portion can further buffer and absorb the impact in the case that the battery monomer is subjected to impact, vibration or other loads, so as to effectively reduce the deformation or non-deformation of the connection area between the electrode terminal assembly and the first wall, thereby reducing the risk of sealing failure due to the existence of a large gap between the electrode terminal assembly and the first wall, improving the sealing performance of the battery monomer, and further improving the use performance of the battery. At the same time, the setting mode of the buffer portion is simple and flexible, facilitating processing and manufacturing.

[0017] In some implementations, in the plane perpendicular to the thickness direction of the first wall, the buffer portion includes a plurality of sub-buffer portions, and the plurality of sub-buffer portions are arranged at intervals around the outer periphery of the electrode terminal assembly.

[0018] In the embodiment of the present application, in the plane perpendicular to the thickness direction of the first wall, by setting the buffer portion to include a plurality of sub-buffer portions, and the plurality of sub-buffer portions are arranged at intervals around the outer periphery of the electrode terminal assembly, compared with the buffer portion continuously arranged around the outer periphery of the electrode terminal assembly, the space formed between adjacent sub-buffer portions can provide additional buffer space, so as to further improve the buffering and absorption effect of the buffer portion on external impact, thereby improving the sealing performance of the battery monomer and the use performance of the battery in the case that the battery monomer is subjected to impact, vibration or other loads.

[0019] In some implementations, in the plane perpendicular to the thickness direction of the first wall, the first wall includes a plurality of buffer portions, and the plurality of buffer portions are arranged at intervals around the outer periphery of the electrode terminal assembly away from the center of the electrode terminal assembly.

[0020] In the embodiment of the present application, in a plane perpendicular to the thickness direction of the first wall, by setting the buffer portion as a plurality of buffer portions, the plurality of buffer portions are arranged in a direction away from the center of the electrode terminal assembly and are arranged around the outer periphery of the electrode terminal assembly, so as to further improve the buffering and absorbing effect of the buffer portion on external impact, thereby improving the sealing performance of the battery monomer under the condition that the battery monomer is subjected to impact, vibration and other loads, and improving the use performance of the battery.

[0021] In some implementations, the first wall further comprises a body portion, and the body portion and the buffer portion are in an integrated structure. In this way, in the embodiment of the present application, by setting the body portion and the buffer portion in the first wall as an integrated structure, the buffering and absorbing effect of the buffer portion on external impact is effectively improved under the condition that the battery monomer is subjected to impact, vibration and other loads, thereby reducing the risk of sealing failure between the electrode terminal assembly and the first wall, improving the sealing performance of the battery monomer, and further improving the use performance of the battery, while improving the manufacturing efficiency of the battery and reducing the processing manufacturing cost.

[0022] In some implementations, the battery monomer further comprises an end cover, the first wall comprises at least part of the end cover, and / or the first wall comprises at least part of a shell of the battery monomer. In this way, in the embodiment of the present application, the battery monomer further comprises an end cover, by setting at least part of the end cover as the first wall, and / or setting at least part of the shell of the battery monomer as the first wall, so that the setting mode of the buffer portion is simple and flexible, and the processing and manufacturing of the battery are facilitated.

[0023] In some implementations, the first wall is further provided with a liquid injection hole and / or a counterbore, and in a plane perpendicular to the thickness direction of the first wall, the orthographic projection of the buffer portion does not overlap with the orthographic projection of the liquid injection hole and / or the counterbore.

[0024] In the embodiment of the present application, by setting the liquid injection hole and / or the counterbore on the first wall, and in a plane perpendicular to the thickness direction of the first wall, the orthographic projection of the buffer portion does not overlap with the orthographic projection of the liquid injection hole and / or the counterbore, thereby reducing the influence of the setting of the buffer portion on the function of the liquid injection hole and / or the counterbore, so as to take into account the use performance of the buffer portion and the liquid injection hole and / or the counterbore, and further improve the use performance of the battery.

[0025] In a second aspect, an end cover assembly is provided for use in the battery cell of any of the implementations of the first aspect. The end cover assembly includes an end cover having a through hole extending through the end cover along a thickness direction of the end cover; and an electrode terminal assembly sealingly connected to the end cover and electrically connected to the electrode assembly through the through hole. The end cover further includes a buffer portion disposed around an outer periphery of the electrode terminal assembly, and the buffer portion has a thickness smaller than a thickness of a remaining portion of the end cover excluding the buffer portion.

[0026] In the embodiments of the present application, by disposing the buffer portion around the outer periphery of the electrode terminal assembly in the end cover assembly, and by setting the thickness of the buffer portion to be smaller than the thickness of the remaining portion of the end cover excluding the buffer portion, in the case where the battery cell is subjected to an impact, vibration or other load, the buffer portion can buffer and absorb the external impact, so as to reduce the deformation or non-deformation of the connection region between the electrode terminal assembly and the end cover, thereby reducing the risk of seal failure due to the existence of a large gap between the electrode terminal assembly and the end cover, improving the sealing performance of the battery cell, and further improving the use performance of the battery.

[0027] In some implementations, the minimum thickness of the buffer portion is greater than the thickness of the shell of the battery cell, and the maximum thickness of the buffer portion is smaller than the thickness of a cantilever beam of the end cover, the thickness of the cantilever beam being the minimum thickness of the portion of the end cover sealingly connected to the electrode terminal assembly.

[0028] In the embodiments of the present application, by setting the maximum thickness of the buffer portion to be smaller than the thickness of the cantilever beam of the end cover, the thickness of the cantilever beam being the minimum thickness of the portion of the end cover sealingly connected to the electrode terminal assembly, in the case where the battery cell is subjected to an impact, vibration or other load, compared to the connection region between the electrode terminal assembly and the end cover, the buffer portion can be deformed preferentially to buffer and absorb the external impact, while the minimum thickness of the buffer portion is set to be greater than the thickness of the shell of the battery cell, so as to improve the connection strength between the electrode terminal assembly and the end cover, thereby improving the sealing performance of the battery cell, and further improving the use performance of the battery.

[0029] In some implementations, in a direction perpendicular to the thickness direction of the end cover, the minimum distance L1 between the side of the electrode terminal assembly close to the buffer portion and the outer wall of the buffer portion close to the electrode terminal assembly is greater than or equal to 0.5 mm.

[0030] In the embodiment of the present application, in the thickness direction perpendicular to the end cover, by setting the distance L1 between the side of the electrode terminal assembly close to the buffer portion and the outer wall of the buffer portion close to the electrode terminal assembly to be greater than or equal to 0.5 mm, the damage of the electrode terminal assembly and the end cover to the buffer portion in the process of welding connection is reduced, the influence on the use performance of the buffer portion is reduced, the sealing performance of the battery monomer under the condition of impact, vibration and other loads is improved, and the use performance of the battery is improved.

[0031] In a third aspect, a battery is provided, including a box body including a top plate and a bottom plate arranged oppositely, and a battery monomer according to the first aspect, which is contained in the box body.

[0032] In some implementations, the electrode terminal assembly of the battery monomer is arranged towards the bottom plate.

[0033] In the embodiment of the present application, compared with the technical solution of arranging the battery monomer upright, by arranging the electrode terminal assembly of the battery monomer towards the bottom plate, the arrangement of the battery monomer is more flexible, and the assembly of the battery is facilitated.

[0034] In a fourth aspect, a power consuming device is provided, including the battery of the third aspect, which is used to provide electric energy for the power consuming device.

[0035] In some implementations, the power consuming device can be a vehicle, a ship or a spacecraft, etc.

[0036] In a fifth aspect, an energy storage device is provided, including the battery of the third aspect, which is used to store electric energy for the energy storage device. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0038] FIG. 1 is a structural schematic diagram of a vehicle according to an embodiment of the present application.

[0039] FIG. 2 is a structural schematic diagram of a battery according to an embodiment of the present application.

[0040] FIG. 3 is a structural schematic diagram of a battery monomer according to an embodiment of the present application.

[0041] FIG. 4 is an exploded structural schematic diagram of a battery monomer according to an embodiment of the present application.

[0042] Figure 5 is a structural schematic diagram of an end cap assembly provided in an embodiment of this application.

[0043] Figure 6 is a cross-sectional schematic diagram of an end cap assembly provided in an embodiment of this application.

[0044] Figure 7 is a structural schematic diagram of an end cap assembly provided in another embodiment of this application.

[0045] Figure 8 is a cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0046] Figure 9 is a cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0047] Figure 10 is a partially enlarged cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0048] Figure 11 is a cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0049] Figure 12 is a partially enlarged cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0050] Figure 13 is a cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0051] Figure 14 is a partially enlarged cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0052] Figure 15 is a cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0053] Figure 16 is a cross-sectional schematic diagram of an end cap assembly provided in another embodiment of this application.

[0054] Explanation of reference numerals in the attached drawings: 1-Vehicle; 10-Battery; 20-Battery cell; 30-Controller; 40-Motor; 50-First wall; 11-Box; 21-Shell; 22-Electrode assembly; 211-Shell; 2-End cap assembly; 212-End cap; 2121-Cantilever beam; 213-Pressure relief mechanism; 221a-First tab; 222a-Second tab; 214-Electrode terminal; 214a-Positive electrode terminal; 214b-Negative electrode terminal; 215-First surface; Through hole; 216; 300-Electrode terminal assembly; 310-Insulator; 320-Conductive component; 217-Sealer; 218-Injection hole; 219-Counterhole; 220-Opening; 230-Engraved section; 400-Buffer section; 410-Groove; Sub-buffer section 420.

[0055] The accompanying drawings are not drawn to scale. Detailed Implementation

[0056] The implementation of the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, i.e., the present application is not limited to the described embodiments.

[0057] In the description of the embodiments of the present application, it should be noted that, unless otherwise specified, the meaning of "a plurality of" is more than two; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer" and the like is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

[0058] The orientation words appearing in the following description are the directions shown in the drawings, and are not a limitation on the specific structure of the present application. In the description of the embodiments of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0059] The term "and / or" in the embodiments of the present application is only to describe the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists, A and B exist, and B exists. In addition, the character " / " in the embodiments of the present application generally represents that the front and rear associated objects have an "or" relationship.

[0060] Unless otherwise defined, all technical and scientific terms used in the embodiments of the present application have the same meanings as those commonly understood by those skilled in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the embodiments of the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application or the above description of the drawings are used to distinguish different objects, and are not used to describe a particular order or primary and secondary relationship.

[0061] Reference to an "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to those of ordinary skill in the art, embodiments described in this application can be combined with other embodiments in accordance with the application.

[0062] A battery in embodiments of the application refers to a physical module that includes one or more battery cells to provide electrical energy. For example, a battery referred to in this application can include a battery module or a battery pack, etc. A battery generally includes a case for packaging one or more battery cells. The case can reduce the influence of liquid or other foreign matter on the charging or discharging of the battery cells.

[0063] It should be understood that a battery cell in embodiments of the application includes, but is not limited to, a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc.

[0064] In some implementations, a battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are embedded and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, and can prevent the positive and negative electrodes from short-circuiting while allowing the active ions to pass through.

[0065] In some implementations, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0066] By way of example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0067] By way of example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a high polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a high polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0068] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. In some implementations, other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only one or in combination of two or more. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4, which can also be 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 manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0069] As an example, the positive electrode active material can include at least one of a sodium transition metal oxide, a polyanion compound, and a Prussian blue compound.

[0070] In some implementations, the sodium transition metal oxide can be a sodium transition metal oxide that is doped and modified, and the doping and modification of the sodium transition metal oxide can include at least one of sodium site doping and modification, oxygen site doping and modification, transition metal site doping and modification, and surface coating modification.

[0071] In some implementations, the positive electrode can employ a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When the foamed metal is used as the positive electrode, the surface of the foamed metal can not be provided with the positive electrode active material, or of course can be provided with the positive electrode active material. As an example, the foamed metal can also be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, and the lithium source material is a lithium metal and / or a lithium-rich material.

[0072] In some implementations, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0073] As an example, the negative electrode current collector can employ a metal foil, a foamed metal, or a composite current collector. For example, as the metal foil, silver surface treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be used. The composite current collector can include a polymer material base layer and a metal layer. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0074] In some implementations, the battery cell in the embodiments of the present application can be a negative electrode-free sodium secondary battery.

[0075] The negative electrode-free sodium secondary battery refers to a battery cell formed without actively arranging a negative active material layer on the negative electrode side during the manufacturing process of the battery cell. For example, a sodium metal or carbon active material layer is not arranged on the negative electrode by a coating or deposition process during the manufacturing process of the battery cell to form the negative active material layer. During the first charging, sodium ions obtain electrons on the anode side to deposit and form a sodium metal phase on the surface of the current collector. During discharging, the metal sodium can be converted into sodium ions to return to the positive electrode, thereby realizing cyclic charging and discharging. Compared with other sodium secondary batteries, the negative electrode-free sodium secondary battery cell can obtain a higher energy density due to the absence of the negative active material layer.

[0076] In some implementations, in order to improve the performance of the battery cell, a functional coating such as a carbon material, a metal oxide, an alloy, or the like can be arranged on the negative electrode side of the negative electrode-free sodium secondary battery to improve the conductivity of the negative electrode current collector and improve the uniformity of the deposited sodium metal.

[0077] In some implementations, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0078] In some implementations, the electrode assembly further includes a separator arranged between the positive electrode and the negative electrode.

[0079] In some implementations, the separator is a separator film. The type of the separator film is not particularly limited in the embodiments of the present application, and any known porous structure separator film with good chemical stability and mechanical stability can be selected.

[0080] For example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic.

[0081] In some implementations, the separator is a solid-state electrolyte. The solid-state electrolyte is arranged between the positive electrode and the negative electrode, and simultaneously functions as an ion transmission and a separator for the positive electrode and the negative electrode.

[0082] In some implementations, the battery cell further includes an electrolyte arranged between the positive electrode and the negative electrode to conduct ions. The type of the electrolyte is not particularly limited in the embodiments of the present application, and can be selected according to requirements. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0083] In some implementations, the electrode assembly can be a roll structure. The positive electrode sheet and the negative electrode sheet are rolled into the roll structure.

[0084] In some implementations, the electrode assembly is a laminated structure. For example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be arranged alternately and laminated.

[0085] As an example, the positive electrode sheet can be provided in a plurality of pieces, and the negative electrode sheet can be folded to form a plurality of folded sections arranged in layers.

[0086] As an example, the positive electrode sheet and the negative electrode sheet can each be folded to form a plurality of folded sections arranged in layers.

[0087] As an example, a plurality of separators can be provided, each provided between any adjacent positive electrode sheet or negative electrode sheet.

[0088] As an example, a separator can be provided continuously, and provided between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0089] In some implementations, the electrode assembly can have a shape of a cylinder, a flat, a polygonal prism, or the like.

[0090] In some implementations, the electrode assembly can be provided with tabs, which can guide current out of the electrode assembly. The tabs can include positive tabs and negative tabs.

[0091] In some implementations, the battery cell can include a housing. The housing can be used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (e.g., polypropylene), a composite metal shell (e.g., a copper-aluminum composite shell), or an aluminum-plastic film, or the like.

[0092] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of another shape. The prismatic battery cell can include a square battery cell, a blade battery cell, a polygonal prism battery cell (e.g., a hexagonal prism battery cell), or the like.

[0093] To meet different power demands, the battery according to embodiments of the present application can include a plurality of battery cells. The plurality of battery cells can be connected in series, in parallel, or in a hybrid connection. The hybrid connection refers to a mixture of series and parallel connections. In some implementations, the plurality of battery cells can be connected in series, in parallel, or in a hybrid connection to form a battery module, and the plurality of battery modules can be connected in series, in parallel, or in a hybrid connection to form a battery. That is, the plurality of battery cells can be directly connected to form a battery, or the plurality of battery cells can be connected to form a battery module, and the battery module can be connected to form a battery. The battery can be further provided in an electrical device to provide power to the electrical device.

[0094] In some implementations, the battery according to embodiments of the present application can be a battery module. When there are a plurality of battery cells, the plurality of battery cells can be arranged and fixed to form a battery module.

[0095] In some implementations, the battery according to embodiments of the present application can be a battery pack. The battery can include a box and battery cells, and the battery cells or the battery module can be accommodated in the box.

[0096] In some implementations, the box in the embodiments of the present application can be part of the chassis structure of the vehicle. For example, part of the box can be at least part of the floor of the vehicle, or part of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0097] With the increasing environmental pollution, new energy industry is attracting more and more attention. In the new energy industry, battery technology is an important factor for its development. In the development of battery technology, in addition to improving the electrical performance of the battery, safety is also an important issue that cannot be ignored. If the safety of the battery cannot be guaranteed, the battery cannot be used, which reduces the use performance of the battery. At present, when the battery monomer is subjected to external impact under different working conditions, for example, when the side of the end cover assembly of the battery away from the electrode assembly is subjected to external impact, the electrode terminal is easily damaged, the electrode terminal is deformed, and a gap is generated between the electrode terminal and the seal below the electrode terminal, which causes sealing failure, and further causes electrolyte leakage, affects the sealing performance of the battery monomer, and reduces the use performance of the battery. Therefore, how to improve the use performance of the battery has become a technical problem to be solved in the art.

[0098] Therefore, the embodiments of the present application provide a battery monomer, which comprises an electrode assembly, an electrode terminal assembly, and a first wall, the first wall comprises a through hole which penetrates the first wall along the thickness direction of the first wall, the electrode terminal assembly is sealingly connected with the first wall, and the electrode terminal assembly is electrically connected with the electrode assembly through the through hole; the first wall further comprises a buffer portion, the buffer portion is arranged around the outer periphery of the electrode terminal assembly, and the thickness of the buffer portion is less than the thickness of the part of the first wall other than the buffer portion. In this way, in the embodiments of the present application, by arranging the buffer portion on the first wall of the battery monomer, the buffer portion is arranged around the outer periphery of the electrode terminal assembly arranged on the first wall in the battery monomer, and the thickness of the buffer portion is less than the thickness of the part of the first wall other than the buffer portion. In the case that the battery monomer is subjected to impact, vibration or other loads, the buffer portion can buffer and absorb the impact, so as to reduce the deformation or non-deformation of the connection area between the electrode terminal assembly and the first wall, thereby reducing the risk of sealing failure caused by the existence of a large gap between the electrode terminal assembly and the first wall, improving the sealing performance of the battery monomer, and further improving the use performance of the battery.

[0099] The technical solutions described in the embodiments of the present application are applicable to various power consumption devices using batteries. For example, the power consumption device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes a metal cutting tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer, etc.

[0100] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the above-described power consumption devices, but also applicable to all devices using batteries. The following embodiments will be described in detail with the power consumption device as a vehicle for brevity.

[0101] For example, as shown in FIG. 1, a structural schematic diagram of a vehicle 1 provided by the embodiments of the present application is shown. The vehicle 1 can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The vehicle 1 can be provided with a motor 40, a controller 30, and a battery 10 inside. The controller 30 is used to control the battery 10 to supply power to the motor 40. For example, the battery 10 can be arranged at the bottom, the front, or the rear of the vehicle 1. The battery 10 can be used for power supply of the vehicle 1. For example, the battery 10 can be used as an operating power source of the vehicle 1, and used for circuit systems of the vehicle 1. For another example, the battery 10 can be used for power demand of starting, navigation, and running of the vehicle 1. In some implementations of the present application, the battery 10 can not only be used as an operating power source of the vehicle 1, but also be used as a driving power source of the vehicle 1, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1.

[0102] In order to meet different power consumption requirements, the battery 10 in the embodiments of the present application can include at least one battery cell group, and the battery cell group includes a plurality of battery cells. The plurality of battery cells can be electrically connected by series connection, parallel connection, or mixed connection to form the battery 10, wherein the mixed connection refers to a mixture of series connection and parallel connection. The battery 10 can also be referred to as a battery pack. For example, the plurality of battery cells can be first connected by series connection, parallel connection, or mixed connection to form a battery module, and the plurality of battery modules are connected by series connection, parallel connection, or mixed connection to form the battery 10. That is, the plurality of battery cells can be directly connected to form the battery 10, or the plurality of battery cells can be first connected to form a battery module, and then the battery module is connected to form the battery 10.

[0103] In some embodiments, the battery 10 can include a plurality of battery cells 20. For example, as shown in FIG. 2, which is a schematic diagram of a structure of a battery 10 according to an embodiment of the present application, the battery 10 can include a plurality of battery cells 20. The battery 10 can further include a box 11, which is hollow inside, and the plurality of battery cells 20 can be accommodated in the box 11. For example, the plurality of battery cells 20 can be arranged in parallel or in series or in a combination of parallel and series in the box 11.

[0104] In some embodiments, the battery 10 can further include other structures, which will not be described herein. For example, the battery 10 can further include a current collecting component for realizing electrical connection between the plurality of battery cells 20, such as parallel connection or series connection or a combination of parallel and series connection. Specifically, the current collecting component can realize electrical connection between the plurality of battery cells 20 by connecting the electrode terminals of the battery cells 20. Further, the current collecting component can be fixed to the electrode terminals of the battery cells 20 by welding. The electrical energy of the plurality of battery cells 20 can be further led out through the box by a conductive mechanism. Alternatively, the conductive mechanism can also belong to the current collecting component.

[0105] In the embodiments of the present application, the number of battery cells 20 can be set to any value according to different power requirements. The plurality of battery cells 20 can be connected in series, in parallel or in a combination of parallel and series to realize larger capacity or power. Since the number of battery cells 20 included in each battery 10 can be large, in order to facilitate installation, the battery cells 20 can be arranged in groups, and each group of battery cells 20 can form a battery module. The number of battery cells 20 included in the battery module is not limited and can be set according to requirements. The battery 10 can include a plurality of battery modules, and these battery modules can be connected in series, in parallel or in a combination of parallel and series.

[0106] As shown in FIG. 3, a structure diagram of a battery cell 20 according to an embodiment of the present application is shown. The battery cell 20 includes one or more electrode assemblies 22, a housing 211, and an end cover 212. The housing 211 and the end cover 212 form an outer shell 21 or a battery box. The walls of the housing 211 and the walls of the end cover 212 are collectively referred to as the walls of the battery cell 20. For a cuboid battery cell 20, the walls of the housing 211 include a bottom wall and four side walls. The shape of the housing 211 is determined according to the shape of the combined one or more electrode assemblies 22. For example, the housing 211 can be a hollow cuboid or a hollow square or a hollow cylinder. One of the faces of the housing 211 is an open face, i.e., the face does not have a wall so that the inside of the housing 211 is in communication with the outside of the housing 211. For example, when the housing 211 is a hollow cuboid or a hollow square, one of the flat faces of the housing 211 is the open face. When the housing 211 is a hollow cylinder, one of the end faces of the housing 211 is the open face. The end cover 212 covers the open face and is connected to the housing 211 to form a closed cavity in which the electrode assembly 22 is placed. The housing 211 is filled with an electrolyte, such as an electrolyte solution.

[0107] The battery cell 20 can further include two electrode terminals 214, which can be arranged on the end cover 212. The end cover 212 is generally a flat plate, and the two electrode terminals 214 are fixed to the flat face of the end cover 212. The two electrode terminals 214 are respectively a positive electrode terminal 214a and a negative electrode terminal 214b. Each of the electrode terminals 214 is provided with a connecting member, which can also be referred to as a current collecting member, between the end cover 212 and the electrode assembly 22, for electrically connecting the electrode assembly 22 and the electrode terminal 214.

[0108] As shown in FIG. 3, each of the electrode assemblies 22 has a first tab 221a and a second tab 222a. The first tab 221a and the second tab 222a have opposite polarities. For example, when the first tab 221a is a positive electrode tab, the second tab 222a is a negative electrode tab.

[0109] In the battery cell 20, the electrode assemblies 22 can be arranged as a single electrode assembly or multiple electrode assemblies according to actual use requirements. As shown in FIG. 3, the battery cell 20 is provided with two independent electrode assemblies 22.

[0110] The battery cell 20 can further be provided with a pressure relief mechanism 213. The pressure relief mechanism 213 is actuated to release the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a threshold value.

[0111] The pressure relief mechanism 213 can be various possible pressure relief structures. For example, the pressure relief mechanism 213 can be a temperature-sensitive pressure relief mechanism configured to be able to melt when the internal temperature of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value; and / or, the pressure relief mechanism 213 can be a pressure-sensitive pressure relief mechanism configured to be able to rupture when the internal air pressure of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value.

[0112] FIG. 4 shows an exploded structural schematic diagram of a battery cell 20 according to another embodiment of the present application. FIG. 5 shows a structural schematic diagram of an end cover assembly 2 according to another embodiment of the present application. FIG. 6 shows a cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. FIG. 7 shows a structural schematic diagram of the end cover assembly 2 according to another embodiment of the present application. FIG. 8 shows a cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. FIG. 9 shows a cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. FIG. 10 shows a partially enlarged cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. For example, FIG. 6 can be a cross-sectional schematic diagram of the end cover assembly 2 in FIG. 4, FIG. 8 can be a cross-sectional schematic diagram of the end cover assembly 2 in FIG. 7, and FIG. 9 can be a cross-sectional schematic diagram of the end cover assembly 2 in FIG. 4. FIG. 10 can be an enlarged cross-sectional schematic diagram of the corresponding part of the end cover assembly 2 in FIG. 9. FIG. 11 shows a cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. FIG. 12 shows a partially enlarged cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. FIG. 13 shows a cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. FIG. 14 shows a partially enlarged cross-sectional schematic diagram of the end cover assembly 2 according to another embodiment of the present application. For example, FIG. 12 can be an enlarged cross-sectional schematic diagram of the corresponding part of the end cover assembly 2 in FIG. 11, and FIG. 14 can be an enlarged cross-sectional schematic diagram of the corresponding part of the end cover assembly 2 in FIG. 13.

[0113] It should be understood that, in the embodiments of the present application, for the convenience of description, as shown in FIGS. 4 to 14, the battery cell 20 in the diagram is taken as a square battery as an example, the direction X can be the length direction of the battery cell 20, the direction X is perpendicular to the direction Z and the direction Y, or the direction X can also be the length direction of the end cover 212, or the direction X can also be the length direction of the shell 211; the direction Y can be the width direction of the battery cell 20, the direction Y is perpendicular to the direction Z and the direction X, or the direction Y can also be the width direction of the end cover assembly 2, or the direction Y can also be the width direction of the end cover 212, or the direction Y can also be the width direction of the shell 211; the direction Z can be the height direction of the battery cell 20, the direction Z is perpendicular to the direction X and the direction Y, or the direction Z can also be the thickness direction of the end cover assembly 2, or the direction Z can also be the thickness direction of the end cover 212, or the direction Z can also be the height direction of the shell 211.

[0114] In some implementations, as shown in FIGS. 4-14, the battery cell 20 includes an electrode assembly 22, an electrode terminal assembly 300, and a first wall 50 including a through hole 216 extending through the first wall 50 along a thickness direction of the first wall 50, the electrode terminal assembly 300 being sealingly connected with the first wall 50 and being electrically connected with the electrode assembly 22 through the through hole 216, and the first wall 50 further including a buffer portion 400 disposed around an outer periphery of the electrode terminal assembly 300, the buffer portion 400 having a thickness smaller than a thickness of a portion of the first wall 50 other than the buffer portion 400.

[0115] It should be understood that the battery cell 20 in the embodiments of the present application can include a plurality of walls, and the first wall 50 in the embodiments of the present application can be any one of the walls of the battery cell 20, which includes but is not limited to the following examples: the first wall 50 can be the wall with the smallest area of the battery cell 20; the first wall 50 can also be the wall with the largest area of the battery cell 20; the first wall 50 can be at least part of the housing 211 of the battery cell 20; and the first wall 50 can be at least part of the end cover 212. Hereinafter, at least part of the end cover 212 is taken as the first wall 50 for detailed description.

[0116] It should also be understood that, in the embodiments of the present application, in the case where the first wall 50 is at least part of the end cover 212, the shape of the through hole 216 provided on the end cover 212 can be set according to actual needs, and for example, the shape of the through hole 216 can be matched and set according to the shape of the electrode terminal assembly 300, which is not limited in the embodiments of the present application.

[0117] It should also be understood that, in the embodiments of the present application, the end cover assembly 2 includes the end cover 212 and the electrode terminal assembly 300, the electrode terminal assembly 300 being sealingly connected with the end cover 212 through the through hole 216, and the end cover assembly 2 can further be provided with a sealing member 217 attached to the through hole 216, the sealing member 217 being capable of cooperating with the electrode terminal assembly 300 to limit the position of the electrode terminal assembly 300 in the through hole 216, which is conducive to reducing the risk of the electrode terminal assembly 300 falling off when subjected to impact, vibration, or other loads, and improving the sealing performance of the battery cell 20.

[0118] It should also be understood that, in the embodiments of the present application, the sealing member 217 and the electrode terminal assembly 300 can be connected by injection molding, so that the electrode terminal assembly 300 and the sealing member 217 are integrally formed, thereby strengthening the connection strength between the sealing member 217 and the electrode terminal assembly 300.

[0119] It should also be understood that, as shown in FIG. 8, the electrode terminal assembly 300 in the embodiment of the present application can include the electrode terminal 214, the insulating member 310 and the conductive member 320, wherein the insulating member 310 is arranged around the electrode terminal 214, and specifically, the insulating member 310 can be formed by injection molding around the electrode terminal 214, so as to realize insulation and isolation between the electrode terminal assembly 300 and the end cover 212; at least part of the conductive member 320 is arranged inside the insulating member 310, and the conductive member 320 is used to electrically connect the electrode terminal 214 and the end cover 212. It should also be understood that the electrode terminal assembly 300 in the embodiment of the present application can refer to a positive electrode terminal assembly or a negative electrode terminal assembly.

[0120] It should also be understood that the material of the insulating member 310 can be a plastic material. For example, the material of the insulating member 310 includes at least one of the following materials: a polyethylene material, a polypropylene material or a polystyrene material.

[0121] It should also be understood that, in the embodiment of the present application, the buffer portion 400 and the end cover 212 can be integrally formed or separately formed, and in the case of separate formation of the buffer portion 400 and the end cover 212, the buffer portion 400 can be welded to the end cover 212; in the case of integral formation of the buffer portion 400 and the end cover 212, the buffer portion 400 can be formed by stamping the end cover 212 in the thickness direction of the end cover 212, or the end cover 212 can be thinned or reduced in the thickness direction of the end cover 212.

[0122] It should also be understood that, in the embodiment of the present application, the thickness of the buffer portion 400 being less than the thickness of the part of the first wall 50 other than the buffer portion 400 can refer to, for example, the average thickness of the buffer portion 400 being less than the average thickness of the part of the end cover 212 other than the buffer portion 400, or the maximum thickness of the buffer portion 400 being less than the maximum thickness of the part of the end cover 212 other than the buffer portion 400, or the minimum thickness of the buffer portion 400 being less than the minimum thickness of the part of the end cover 212 other than the buffer portion 400.

[0123] It should also be understood that the shape of the buffer portion 400 in the plane perpendicular to the thickness direction of the end cover 212 can be set according to actual needs. For example, as shown in FIGS. 5-8, the shape of the buffer portion 400 in the plane perpendicular to the thickness direction of the end cover 212 can be a circular ring or a rounded rectangular ring. In this way, in the embodiments of the present application, by setting the shape of the buffer portion 400 to be a circular ring or a rounded rectangular ring in the plane perpendicular to the thickness direction of the end cover 212, the processing and manufacturing of the buffer portion 400 are facilitated, which can effectively reduce the process complexity of the end cover assembly 2 and reduce the processing cost of the end cover assembly 2.

[0124] It should also be understood that in the embodiments of the present application, the first surface 215 of the end cover 212 is also provided with a liquid injection hole 218, a counterbore 219, and a code portion 230. The first surface 215 is the surface of the end cover 212 away from the electrode assembly 22 of the battery cell 20. The electrolyte can be injected into the interior of the battery cell 20 through the liquid injection hole 218 to supplement the electrolyte of the battery cell 20. The counterbore 219 can be used for exhaust and pressure relief. For example, the counterbore 219 can be used to discharge the gas generated inside the battery cell 20, such as the gas that may be generated during charging or discharging. The counterbore 219 can effectively exhaust the gas to prevent the accumulation of gas inside the battery cell 20 from causing excessive pressure and even causing safety problems. The counterbore 219 can also be used for temperature control to maintain the stability of the temperature inside the battery cell 20. That is, through the counterbore 219, the heat inside the battery cell 20 can be more easily dissipated, which helps to control the temperature of the battery cell 20 and improve the performance and life of the battery cell 20. In addition, the counterbore 219 can also function as a safety valve to release the internal pressure of the battery cell 20 and reduce the risk of explosion. If the liquid inside the battery cell 20 leaks, the counterbore 219 can help the liquid to be discharged to reduce the risk of liquid accumulation inside the battery cell 20 and reduce the impact on the performance of the battery cell 20 and the surrounding environment. The code portion 230 is usually used to identify the relevant information of the battery cell 20, such as the manufacturer, the production date, the model, the batch, etc.

[0125] It should also be understood that in the embodiments of the present application, as shown in FIG. 4, the housing 211 in the battery cell 20 has an opening 220, and the electrode assembly 22 is accommodated inside the housing 211. The end cover assembly 2 covers the opening 220.

[0126] In the embodiments of the present application, by arranging the buffer portion 400 on the first wall 50 of the battery monomer 20, the buffer portion 400 is arranged around the outer periphery of the electrode terminal assembly 300 arranged on the first wall 50 of the battery monomer 20, the thickness of the buffer portion 400 is less than the thickness of the part of the first wall 50 other than the buffer portion 400, in the case where the battery monomer 20 is subjected to impact, vibration or other load, the buffer portion 400 can play a role of buffering and absorbing the impact, so as to reduce the deformation or non-deformation of the connection area between the electrode terminal assembly 300 and the first wall 50, thereby reducing the risk of seal failure due to the existence of a large gap between the electrode terminal assembly 300 and the first wall 50, so as to improve the sealing performance of the battery monomer 20, and further improve the use performance of the battery 10.

[0127] In some implementations, the minimum thickness of the buffer portion 400 is greater than the thickness of the shell 211 of the battery monomer 20, and the maximum thickness of the buffer portion 400 is less than the first thickness, the first thickness being the minimum thickness of the part of the first wall 50 that is sealingly connected with the electrode terminal assembly 300.

[0128] For example, in the case where the first wall 50 is at least part of the end cover 212, the first thickness can be the thickness of the cantilever beam 2121 of the end cover 212, the thickness of the cantilever beam 2121 being the minimum thickness of the part of the end cover 212 that is sealingly connected with the electrode terminal assembly 300, for example, the thickness of the cantilever beam 2121 can be D1 shown in FIG. 10, FIG. 12 or FIG. 14.

[0129] It should be understood that the thickness D1 of the cantilever beam 2121 described above can be less than or equal to the thickness of the end cover 212, the value of the thickness D1 of the cantilever beam 2121 can be set according to actual needs, for example, considering the sealing connection between the electrode terminal assembly 300 and the end cover 212, the thickness D1 of the cantilever beam can be less than the thickness of the end cover 212, so as to facilitate the welding of the electrode terminal assembly 300.

[0130] It should also be understood that in the embodiments of the present application, the thickness of the shell 211 of the battery monomer 20 can refer to the thickness of the side wall or the bottom wall of the shell 211, in the case where the thickness of the shell 211 of the battery monomer 20 is the thickness of the side wall of the shell 211, the thickness of the shell 211 can refer to the maximum thickness, the minimum thickness or the average thickness of the side wall; in the case where the thickness of the shell 211 of the battery monomer 20 is the thickness of the bottom wall of the shell 211, the thickness of the shell 211 can refer to the maximum thickness, the minimum thickness or the average thickness of the bottom wall.

[0131] In the embodiments of the present application, by setting the maximum thickness of the buffer portion 400 to be less than the first thickness, which is the minimum thickness of the portion of the first wall 50 that is sealingly connected to the electrode terminal assembly 300, the buffer portion 400 can be deformed preferentially to buffer and absorb external impact compared to the connection region between the electrode terminal assembly 300 and the first wall 50 in the case where the battery monomer 20 is subjected to impact, vibration, or the like. At the same time, by setting the minimum thickness of the buffer portion 400 to be greater than the thickness of the housing 211 of the battery monomer 20, the connection strength between the electrode terminal assembly 300 and the first wall 50 is improved, thereby improving the sealing property of the battery monomer 20 and further improving the use performance of the battery 10.

[0132] In some implementations, as shown in FIGS. 8, 12, or 14, in the thickness direction perpendicular to the first wall 50, the minimum distance L1 between the side of the electrode terminal assembly close to the buffer portion and the outer wall of the buffer portion close to the electrode terminal assembly is greater than or equal to 0.5 mm.

[0133] It should be understood that in the embodiments of the present application, in the case where the battery monomer 20 is a square battery, the thickness direction perpendicular to the first wall 50 can be the length direction of the battery monomer, i.e., the direction X shown in FIGS. 8, 12, or 14.

[0134] In the embodiments of the present application, in the thickness direction perpendicular to the first wall 50, by setting the distance L1 between the side of the electrode terminal assembly 300 close to the buffer portion 400 and the outer wall of the buffer portion 400 close to the electrode terminal assembly 300 to be greater than or equal to 0.5 mm, the damage to the buffer portion 400 by the electrode terminal assembly 300 and the first wall 50 during the welding connection is reduced, the influence on the use performance of the buffer portion 400 is reduced, and thus the sealing property of the battery monomer 20 is improved and the use performance of the battery 10 is improved in the case where the battery monomer 20 is subjected to impact, vibration, or the like.

[0135]

[0136] In some implementations, as shown in FIGS. 8, 12, or 14, in the thickness direction perpendicular to the first wall 50, the minimum distance L1 between the side of the electrode terminal assembly 300 close to the buffer portion 400 and the outer wall of the buffer portion 400 close to the electrode terminal assembly 300 is: 0.5 mm≤L1≤2 mm.

[0137] Exemplarily, in the thickness direction perpendicular to the first wall 50, the distance L1 between the side of the electrode terminal assembly 300 close to the buffer portion 400 and the outer wall of the buffer portion 400 close to the electrode terminal assembly 300 can be set to 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, or the like, or a value within the range obtained by any two of the above values.

[0138] In the embodiments of the present application, in the thickness direction perpendicular to the first wall 50, the distance L1 between the side of the electrode terminal assembly 300 close to the buffer portion 400 and the outer wall of the buffer portion 400 close to the electrode terminal assembly 300 is set to 0.5 mm≤L1≤2 mm, so that in the case where the battery monomer 20 is subjected to impact, vibration or other load, the effect of the buffer portion 400 on buffering and absorbing external impact is effectively improved, and the influence of the electrode terminal assembly 300 and the first wall 50 on the buffer portion 400 during welding is reduced, thereby effectively reducing the risk of sealing failure between the electrode terminal assembly 300 and the first wall 50, improving the sealing performance of the battery monomer 20, and further improving the use performance of the battery 10.

[0139] In some implementations, the buffer portion 400 protrudes away from the electrode assembly 22, and / or the buffer portion 400 protrudes towards the electrode assembly 22.

[0140] Exemplarily, as shown in FIGS. 9 and 10, the buffer portion 400 can protrude away from the electrode assembly 22; as shown in FIGS. 11 and 12, the buffer portion 400 can protrude towards the electrode assembly 22. For example, during the manufacturing of the above-mentioned end cover 212, a portion of the end cover 212 can be subjected to stamping processing so that the stamped portion protrudes away from or towards the electrode assembly 22, or the portion of the end cover 212 can be subjected to thinning processing first, and then subjected to stamping processing so that the stamped portion protrudes away from or towards the electrode assembly 22, and the thickness of the buffer portion 400 is less than the thickness of the portion of the end cover 212 other than the buffer portion 400.

[0141] It should also be understood that in the embodiments of the present application, in the plane perpendicular to the protruding direction of the buffer portion 400, the cross-sectional shape of the buffer portion 400 can include an arc shape, for example, can be a semicircular ring shape as shown in FIGS. 10 or 12.

[0142] In the embodiments of the present application, by setting the buffer portion 400 to protrude in a direction away from the electrode assembly 22 of the battery monomer 20 and / or setting the buffer portion 400 to protrude in a direction close to the electrode assembly 22, the protruding structure of the buffer portion 400 can further buffer and absorb the impact in the case that the battery monomer 20 is subjected to an impact, vibration or other load, so as to effectively reduce the deformation or non-deformation of the connection area between the electrode terminal assembly 300 and the first wall 50, thereby reducing the risk of sealing failure due to the existence of a large gap between the electrode terminal assembly 300 and the first wall 50, improving the sealing performance of the battery monomer 20, and further improving the use performance of the battery 10. Meanwhile, the setting mode of the buffer portion 400 is simple and flexible, and is convenient for processing and manufacturing.

[0143] In some implementations, as shown in FIGS. 13 and 14, a local area on the end cover 212 can be thinned to form a buffer portion 400, and the thickness of the buffer portion 400 is less than the thickness of the part of the end cover 212 other than the buffer portion 400. For example, the local area on the end cover 212 can be mechanically cut or stamp-formed to form the above-mentioned buffer portion 400.

[0144] FIG. 15 shows a cross-sectional schematic view of an end cover assembly 2 provided by another embodiment of the present application.

[0145] In some implementations, as shown in FIG. 15, in a plane perpendicular to the thickness direction of the first wall 50, the buffer portion 400 includes a plurality of sub-buffer portions 420, and the plurality of sub-buffer portions 420 are arranged at intervals around the outer periphery of the electrode terminal assembly 300.

[0146] It should be understood that, in the embodiments of the present application, the distance between the above-mentioned two adjacent sub-buffer portions 420 can be set according to actual needs, and the example embodiments are not limited in this regard. For example, the plurality of sub-buffer portions 420 can be arranged at equal intervals. It should also be understood that the distance between the above-mentioned two adjacent sub-buffer portions 420 can refer to the distance between the geometric centers of the two adjacent sub-buffer portions 420.

[0147] In the embodiments of the present application, in a plane perpendicular to the thickness direction of the first wall 50, by setting the buffer portion 400 to include a plurality of sub-buffer portions 420 and arranging the plurality of sub-buffer portions 420 at intervals around the outer periphery of the electrode terminal assembly 300, compared with the buffer portion 400 continuously arranged around the outer periphery of the electrode terminal assembly 300, the space formed between the adjacent sub-buffer portions 420 can provide additional buffer space, so as to further improve the buffering and absorbing effect of the buffer portion 400 on external impact, thereby improving the sealing performance of the battery monomer 20 in the case that the battery monomer 20 is subjected to an impact, vibration or other load, and improving the use performance of the battery 10.

[0148] FIG. 16 shows a cross-sectional view of the end cover assembly 2 according to another embodiment of the present application.

[0149] In some implementations, as shown in FIG. 16, the first wall 50 includes a plurality of the buffer portions 400 in a plane perpendicular to the thickness direction of the first wall 50, and the plurality of the buffer portions 400 are spaced around the outer periphery of the electrode terminal assembly 300 in a direction away from the center of the electrode terminal assembly 300.

[0150] It should be understood that, in the embodiments of the present application, the plurality of the buffer portions 400 can be spaced around the outer periphery of the electrode terminal assembly 300 in a direction away from the center of the electrode terminal assembly 300 at equal intervals or at unequal intervals, and the embodiments of the present application are not limited thereto as an example. In the case where the plurality of the buffer portions 400 are spaced at equal intervals, the distance between any two adjacent buffer portions 400 of the plurality of the buffer portions 400 can be set according to actual requirements. It should also be understood that the distance between any two adjacent buffer portions 400 of the plurality of the buffer portions 400 refers to the distance between the geometric centers of the two adjacent buffer portions 400 in a direction away from the center of the electrode terminal assembly 300.

[0151] In the embodiments of the present application, in a plane perpendicular to the thickness direction of the first wall 50, by providing the buffer portion 400 in a plurality of the buffer portions 400, the plurality of the buffer portions 400 are spaced around the outer periphery of the electrode terminal assembly 300 in a direction away from the center of the electrode terminal assembly 300, so as to further improve the buffering and absorbing effects of the buffer portion 400 on external impact, thereby improving the sealing performance of the battery monomer 20 in the case where the battery monomer 20 is subjected to impact, vibration or other loads, and improving the use performance of the battery 10.

[0152] In some implementations, the first wall 50 further includes a body portion, and the body portion and the buffer portion 400 are in an integrated structure. As an example, in the case where the first wall 50 is at least part of the end cover 212, the body portion can be at least part of the area of the end cover 212, and at least part of the area of the end cover 212 can be in an integrated structure with the buffer portion 400, i.e., the buffer portion 400 can be formed on the surface of the end cover 212 by stamping the part of the area of the end cover 212, and the buffer portion 400 can include the groove 410 with the opening close to or away from the electrode assembly 22, i.e., the buffer portion 400 is a hollow structure, so as to improve the buffering performance of the buffer portion 400. As another example, in the case where the first wall 50 is at least part of the side wall of the shell 211 of the battery monomer 20, the body portion can be at least part of the area of the side wall of the shell 211, and at least part of the area of the side wall of the shell 211 can be in an integrated structure with the buffer portion 400.

[0153] In the embodiment of the present application, by setting the body part and the buffer part 400 in the first wall 50 as an integrated structure, the buffer part 400 can effectively buffer and absorb external impact in the case of impact, vibration or other loads on the battery monomer 20, thereby reducing the risk of sealing failure between the electrode terminal assembly 300 and the first wall 50, improving the sealing performance of the battery monomer 20, and further improving the use performance of the battery 10, while improving the manufacturing efficiency of the battery 10 and reducing the processing manufacturing cost.

[0154] In some implementations, the battery monomer 20 further includes an end cover 212, the first wall 50 includes at least part of the end cover 212, and / or the first wall 50 includes at least part of the shell 211 of the battery monomer 20. In this way, in the embodiment of the present application, the battery monomer 20 further includes an end cover 212, by setting at least part of the end cover 212 as the first wall 50, and / or setting at least part of the shell 211 of the battery monomer 20 as the first wall 50, the setting method of the above-mentioned buffer part 400 is simple and flexible, and the processing and manufacturing of the battery 10 are facilitated.

[0155] In some implementations, as shown in FIGS. 4-8 and FIGS. 15 and 16, the first wall 50 is further provided with a liquid injection hole 218 and / or a counterbore 219, and in the plane perpendicular to the thickness direction of the first wall 50, the orthographic projection of the buffer part 400 does not overlap with the orthographic projection of the liquid injection hole 218 and / or the counterbore 219.

[0156] It should be understood that in the embodiment of the present application, in the plane perpendicular to the thickness direction of the first wall 50, the orthographic projection of the buffer part 400 can also not overlap with the orthographic projection of the coding part 230, so as to reduce the mutual influence between the buffer part 400 and the coding part 230.

[0157] In the embodiment of the present application, by setting the liquid injection hole 218 and / or the counterbore 219 on the first wall 50, and in the plane perpendicular to the thickness direction of the first wall 50, the orthographic projection of the buffer part 400 does not overlap with the orthographic projection of the liquid injection hole 218 and / or the counterbore 219, thereby reducing the influence of the setting of the buffer part 400 on the function of the liquid injection hole 218 and / or the counterbore 219, so as to take into account the use performance of the buffer part 400 and the liquid injection hole 218 and / or the counterbore 219, and further improve the use performance of the battery 10.

[0158] Referring to FIGS. 4-16 again, a battery cell 20 is provided, which includes an electrode assembly 22, an electrode terminal assembly 300, and a first wall 50 including a through hole 216 penetrating the first wall 50 in a thickness direction of the first wall 50, the electrode terminal assembly 300 being sealingly connected with the first wall 50 and being electrically connected with the electrode assembly 22 through the through hole 216, the first wall 50 further including a buffer portion 400 disposed around an outer periphery of the electrode terminal assembly 300, the buffer portion 400 having a thickness smaller than a thickness of a portion of the first wall 50 other than the buffer portion 400. A minimum thickness of the buffer portion 400 is greater than a thickness of a housing 211 of the battery cell 20, and a maximum thickness of the buffer portion 400 is smaller than a first thickness, the first thickness being a minimum thickness of a portion of the first wall 50 sealingly connected with the electrode terminal assembly 300. In a direction perpendicular to the thickness direction of the first wall 50, a minimum distance L1 between a side of the electrode terminal assembly 300 close to the buffer portion and an outer wall of the buffer portion close to the electrode terminal assembly 300 is greater than or equal to 0.5 mm.

[0159] The battery cell 20 according to any of the above embodiments can further include an end cover assembly 2, which includes an end cover 212 and the electrode terminal assembly 300, the end cover 212 including a through hole 216 penetrating the end cover 212 in a thickness direction of the end cover 212, the electrode terminal assembly 300 being sealingly connected with the end cover 212 and being electrically connected with the electrode assembly 22 through the through hole 216, the end cover 212 further including a buffer portion 400 disposed around an outer periphery of the electrode terminal assembly 300, the buffer portion 400 having a thickness smaller than a thickness of a portion of the end cover 212 other than the buffer portion 400.

[0160] In the battery cell 20 according to any of the above embodiments, the buffer portion 400 is disposed around the outer periphery of the electrode terminal assembly 300 in the end cover assembly 2, and the buffer portion 400 has a thickness smaller than a thickness of a portion of the end cover 212 other than the buffer portion 400. In the case where the battery cell 20 is subjected to an external impact, vibration, or the like, the buffer portion 400 can buffer and absorb the impact, so as to reduce or prevent deformation of a connection region between the electrode terminal assembly 300 and the end cover 212, thereby reducing a risk of seal failure due to a large gap between the electrode terminal assembly 300 and the end cover 212, and improving the sealability of the battery cell 20, and thus improving the use performance of the battery 10.

[0161] In some implementations, the minimum thickness of the buffer portion 400 is greater than the thickness of the shell 211 of the battery cell 20, and the maximum thickness of the buffer portion 400 is less than the thickness of the cantilever beam 2121 of the end cover 212, which is the minimum thickness of the portion of the end cover 212 that is sealingly connected to the electrode terminal assembly 300.

[0162] In the embodiments of the present application, by setting the maximum thickness of the buffer portion 400 to be less than the thickness of the cantilever beam 2121 of the end cover 212, which is the minimum thickness of the portion of the end cover 212 that is sealingly connected to the electrode terminal assembly 300, the buffer portion 400 can be deformed preferentially to buffer and absorb external impact compared to the connection area between the electrode terminal assembly 300 and the end cover 212 in the case that the battery cell 20 is subjected to impact, vibration, or other loads. Meanwhile, by setting the minimum thickness of the buffer portion 400 to be greater than the thickness of the shell 211 of the battery cell 20, the connection strength between the electrode terminal assembly 300 and the end cover 212 is improved, thereby improving the sealing performance of the battery cell 20 and further improving the use performance of the battery 10.

[0163] In some implementations, the minimum distance L1 between the side of the electrode terminal assembly 300 that is close to the buffer portion 400 and the outer wall of the buffer portion 400 that is close to the electrode terminal assembly 300 in the direction perpendicular to the thickness of the end cover 212 is greater than or equal to 0.5 mm.

[0164] In the embodiments of the present application, by setting the distance L1 between the side of the electrode terminal assembly 300 that is close to the buffer portion 400 and the outer wall of the buffer portion 400 that is close to the electrode terminal assembly 300 to be greater than or equal to 0.5 mm in the direction perpendicular to the thickness of the end cover 212, the damage to the buffer portion 400 by the electrode terminal assembly 300 and the end cover 212 during the welding connection is reduced, which reduces the impact on the use performance of the buffer portion 400, thereby improving the sealing performance of the battery cell 20 and the use performance of the battery 10 in the case that the battery cell 20 is subjected to impact, vibration, or other loads.

[0165] The embodiments of the present application also provide a battery 10, which includes a box body 11 including a top plate and a bottom plate arranged oppositely, and the battery cell 20 in any of the above embodiments, which is accommodated in the box body 11.

[0166] In some implementations, the electrode terminal assembly 300 of the battery cell 20 is arranged towards the bottom plate. Exemplarily, the electrode terminal assembly 300 of the battery cell 20 arranged towards the bottom plate can be one or two, if the battery cell 20 includes two electrode terminal assemblies 300, for example, a first electrode terminal assembly and a second electrode terminal assembly, wherein the first electrode terminal assembly can be arranged towards the bottom plate of the box 11, and the first electrode terminal assembly is arranged on the first wall 50 of the battery cell 20, and the other electrode terminal assembly 300 can be arranged on the wall adjacent to or opposite to the first wall 50.

[0167] In the embodiments of the present application, compared with the technical solution of arranging the battery cell 20 upright, by arranging the electrode terminal assembly 300 of the battery cell 20 towards the bottom plate, the arrangement of the battery cell 20 is more flexible, which facilitates the assembly of the battery 10. For example, in the case of application to the vehicle 1, by arranging the electrode terminal assembly 300 of the battery cell 20 towards the bottom plate, the influence of the battery cell 20 on the interior or passenger compartment of the vehicle 1 during the thermal runaway process can be effectively reduced.

[0168] The embodiments of the present application also provide a battery 10 as described above, which is used to provide electric energy for a use electric device. Specifically, the use electric device can be the vehicle 1 shown in FIG. 1, or any use electric device using the battery 10.

[0169] In some implementations, the use electric device can be a vehicle, a ship or a spacecraft, etc.

[0170] The embodiments of the present application also provide a battery 10 as described above, which is used to provide electric energy for a use electric device. Specifically, the use electric device can be the vehicle 1 shown in FIG. 1, or any use electric device using the battery 10.

[0171] Although the present application has been described with reference to the above embodiments, various improvements can be made thereto and equivalents can be substituted therefor without departing from the scope of the embodiments of the present application. In particular, the technical features mentioned in each of the embodiments can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, Comprise: an electrode assembly; an electrode terminal assembly; a first wall including a through hole penetrating the first wall in a thickness direction of the first wall, the electrode terminal assembly being sealingly connected with the first wall, and the electrode terminal assembly being electrically connected with the electrode assembly through the through hole; the first wall further including a buffer portion disposed around an outer periphery of the electrode terminal assembly, a thickness of the buffer portion being smaller than a thickness of a portion of the first wall other than the buffer portion.

2. The battery cell of claim 1, wherein, A minimum thickness of the buffer portion is greater than a thickness of a housing of the battery cell, and a maximum thickness of the buffer portion is smaller than a first thickness, the first thickness being a minimum thickness of a portion of the first wall sealingly connected with the electrode terminal assembly.

3. The battery cell according to claim 1 or 2, characterized in that, In a direction perpendicular to the thickness direction of the first wall, a minimum distance L1 between a side of the electrode terminal assembly close to the buffer portion and an outer wall of the buffer portion close to the electrode terminal assembly is greater than or equal to 0.5 mm.

4. The battery cell of claim 3, wherein, In a direction perpendicular to the thickness direction of the first wall, a minimum distance L1 between a side of the electrode terminal assembly close to the buffer portion and an outer wall of the buffer portion close to the electrode terminal assembly is 0.5 mm ≤ L1 ≤ 2 mm.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The buffer portion is convex in a direction away from the electrode assembly, and / or the buffer portion is convex in a direction close to the electrode assembly.

6. The battery cell according to any one of claims 1 to 5, characterized in that, In a plane perpendicular to the thickness direction of the first wall, the buffer portion includes a plurality of sub-buffer portions, the plurality of sub-buffer portions being spaced apart around an outer periphery of the electrode terminal assembly.

7. The battery cell according to any one of claims 1 to 6, characterized in that, In a plane perpendicular to the thickness direction of the first wall, the first wall includes a plurality of the buffer portions, the plurality of the buffer portions being spaced apart around an outer periphery of the electrode terminal assembly in a direction away from a center of the electrode terminal assembly.

8. The battery cell of any one of claims 1 to 7, wherein, The first wall further includes a body portion, the body portion being an integral structure with the buffer portion.

9. The battery cell of any one of claims 1 to 8, wherein, The battery cell further includes an end cover, the first wall including at least a portion of the end cover, and / or the first wall including at least a portion of a housing of the battery cell.

10. The battery cell of any one of claims 1 to 9, wherein, The first wall is further provided with a liquid injection hole and / or a counterbore, and in a plane perpendicular to the thickness direction of the first wall, a projection of the buffer portion does not overlap with a projection of the liquid injection hole and / or the counterbore.

11. An end cap assembly characterized by, Applied to the battery cell of any one of claims 1 to 10, the end cover assembly comprises: an end cover including a through hole penetrating the end cover in a thickness direction of the end cover; the electrode terminal assembly, the electrode terminal assembly being sealingly connected with the end cover, the electrode terminal assembly being electrically connected with the electrode assembly through the through hole; the end cover further including the buffer portion, the buffer portion being disposed around an outer periphery of the electrode terminal assembly, a thickness of the buffer portion being smaller than a thickness of a remaining portion of the end cover other than the buffer portion.

12. The end cap assembly of claim 11, wherein, A minimum thickness of the buffer portion is greater than a thickness of a housing of the battery cell, and a maximum thickness of the buffer portion is smaller than a thickness of a cantilever beam of the end cover, the thickness of the cantilever beam being a minimum thickness of a portion of the end cover sealingly connected with the electrode terminal assembly.

13. The end cap assembly of claim 11 or 12, wherein, In a thickness direction perpendicular to the end cap, a minimum distance L1 between a side of the electrode terminal assembly close to the buffer portion and an outer wall of the buffer portion close to the electrode terminal assembly is greater than or equal to 0.5 mm.

14. A battery, characterized by Comprising: a box including a top plate and a bottom plate disposed opposite each other, and The battery cell according to any one of claims 1 to 10 is housed in the box.

15. The battery of claim 14, wherein, The electrode terminal assembly of the battery cell is disposed toward the bottom plate.

16. An electrical device, characterized by The battery according to claim 14 or 15 is used to provide electric energy for the electric device.

17. An energy storage device, comprising: The battery according to claim 14 or 15 is used to store electric energy for the energy storage device.

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