Battery monomer, battery device, power utilization device and energy storage device

Abstract

The embodiment of the utility model provides a battery monomer, a battery device, a power utilization device and an energy storage device. The use performance of the battery monomer can be improved. The battery monomer comprises an electrode assembly and a shell, the shell comprises a first containing cavity and a first wall, the electrode assembly is contained in the first containing cavity, the first wall comprises a body part, a first protruding part and a pressure relief part, the first protruding part protrudes out of the body part towards the direction of the electrode assembly, and the first protruding part is connected with the body part and the pressure relief part; the pressure relief part is arranged on the side, close to the electrode assembly, of the first protruding part, the body part, the first protruding part and the pressure relief part define a second containing cavity with an opening away from the electrode assembly, and an inner concave part is arranged on the inner wall of the second containing cavity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, and more particularly, to a battery monomer, a battery device, a power utilization device and an energy storage device. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] In the development process of battery technology, in addition to improving the electrical performance of the battery device, safety is also an issue that cannot be ignored. For example, in the case of high internal pressure or temperature of the battery monomer, if the pressure relief portion cannot be actuated in time, it is easy to cause the deformation or rupture of the shell or internal structure of the battery monomer, and at the same time, it is easy to cause thermal runaway of the battery monomer, thereby reducing the safety of the battery monomer. If the safety of the battery monomer cannot be guaranteed, the battery monomer cannot be used, which reduces the use performance of the battery monomer. Therefore, how to improve the use performance of the battery monomer has become a technical problem to be solved in the art. CONTENT OF THE INVENTION

[0004] The embodiments of the present application provide a battery monomer, a battery device, a power utilization device and an energy storage device, which can improve the use performance of the battery monomer.

[0005] In a first aspect, the present application provides a battery monomer, comprising: an electrode assembly; a shell comprising a first accommodating cavity and a first wall, the electrode assembly is accommodated in the first accommodating cavity, the first wall comprises a body portion, a first protruding portion and a pressure relief portion, the first protruding portion protrudes from the body portion in the direction of the electrode assembly, and the first protruding portion connects the body portion and the pressure relief portion, the pressure relief portion is arranged on the side of the first protruding portion close to the electrode assembly, the body portion, the first protruding portion and the pressure relief portion form a second accommodating cavity with an opening away from the electrode assembly, wherein an inner recess is arranged on the inner wall of the second accommodating cavity.

[0006] In the embodiments of the present application, by setting the shell of the battery monomer to include a first wall, the first wall includes a body part, a first protruding part protruding from the body part towards the direction of the electrode assembly, and a pressure relief part, the first protruding part connects the body part and the pressure relief part, the pressure relief part is arranged on the side of the first protruding part close to the electrode assembly, the body part, the first protruding part and the pressure relief part enclose a second containing cavity with an opening away from the electrode assembly, and the inner wall of the second containing cavity is provided with an inner recess to reduce the relative strength between the pressure relief part, the body part and the first protruding part, in the case that the pressure or temperature inside the battery monomer reaches a threshold value, to facilitate the deformation and cracking of the pressure relief part, so that the pressure relief part can be actuated in time to discharge the high-temperature emissions inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0007] In some embodiments, the inner wall of the second containing cavity includes a planar region and a circular arc region, and the inner recess includes a first inner recess, the first inner recess is arranged in the circular arc region.

[0008] In the embodiments of the present application, by setting the inner wall of the second containing cavity to include a planar region and a circular arc region, and the inner recess includes a first inner recess, and the first inner recess is arranged in the circular arc region, in the case that the pressure or temperature inside the battery monomer reaches a threshold value, the first inner recess arranged in the circular arc region effectively reduces the relative strength between the pressure relief part, the body part and the first protruding part, in the case that the pressure or temperature inside the battery monomer reaches a threshold value, to facilitate the deformation and cracking of the pressure relief part, so that the pressure relief part can be actuated in time to discharge the high-temperature emissions inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0009] In some embodiments, the circular arc region includes a first circular arc region and a second circular arc region opposite in a first direction, the first inner recess includes a first sub-inner recess and a second sub-inner recess, the first sub-inner recess is arranged in the first circular arc region, and the second sub-inner recess is arranged in the second circular arc region, the first direction is the extension direction of the planar region.

[0010] In the embodiments of the present application, by setting the circular arc region to include a first circular arc region and a second circular arc region opposite in the first direction, the first inner recess includes a first sub-inner recess and a second sub-inner recess, the first sub-inner recess is arranged in the first circular arc region, and the second sub-inner recess is arranged in the second circular arc region, in the case that the pressure or temperature inside the battery monomer reaches the threshold value, the first sub-inner recess is arranged in the first circular arc region, and the second sub-inner recess is arranged in the second circular arc region, which can further reduce the relative strength between the pressure relief part, the body part and the first protruding part, facilitate the deformation and cracking of the pressure relief part in the case that the pressure or temperature inside the battery monomer reaches the threshold value, so that the pressure relief part can be timely actuated to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0011] In some embodiments, the first sub-inner recess and the second sub-inner recess are respectively arranged symmetrically in a second direction perpendicular to the first direction.

[0012] In the embodiments of the present application, by respectively arranging the first sub-inner recess and the second sub-inner recess symmetrically in the second direction, the relative strength between the pressure relief part, the body part and the first protruding part can be further reduced, the deformation and cracking of the pressure relief part are facilitated in the case that the pressure or temperature inside the battery monomer reaches the threshold value, so that the pressure relief part can be timely actuated to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer, and facilitating the processing and manufacturing of the battery monomer.

[0013] In some embodiments, the inner recess further includes a second inner recess arranged in the planar region and close to the circular arc region.

[0014] In the embodiments of the present application, by arranging the inner recess to further include a second inner recess arranged in the planar region and close to the circular arc region, in the case that the pressure or temperature inside the battery monomer reaches the threshold value, the second inner recess is arranged in the planar region and close to the circular arc region, which can effectively reduce the relative strength between the pressure relief part, the body part and the first protruding part, facilitate the deformation and cracking of the pressure relief part in the case that the pressure or temperature inside the battery monomer reaches the threshold value, so that the pressure relief part can be timely actuated to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0015] In some embodiments, the inner recess further includes a third inner recess, and a surface of the second accommodating cavity away from the electrode assembly is provided with the third inner recess.

[0016] In the embodiment of the present application, by setting the inner recess to further include a third inner recess, the surface of the second accommodating cavity away from the electrode assembly is provided with the third inner recess, in the case that the pressure or temperature inside the battery monomer reaches a threshold value, the third inner recess is arranged on the surface of the second accommodating cavity away from the electrode assembly, which can effectively reduce the relative strength between the pressure relief part, the body part and the first protruding part, in the case that the pressure or temperature inside the battery monomer reaches a threshold value, to facilitate the deformation and cracking of the pressure relief part, so that the pressure relief part can be actuated in time to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0017] In some embodiments, the battery monomer is a square battery monomer, the second accommodating cavity includes a planar section and a circular arc section in a plane perpendicular to the thickness direction of the first wall, and the first wall includes a first side and a second side perpendicular to each other, wherein the ratio between the size D3 of the first side and the size D4 of the second side satisfies: D3 / D4≥5, and the planar section is parallel to the first side.

[0018] In the embodiment of the present application, by setting the battery monomer to be a square battery monomer, the second accommodating cavity includes a planar section and a circular arc section in a plane perpendicular to the thickness direction of the first wall, and the first wall includes a first side and a second side perpendicular to each other, wherein the ratio between the size D3 of the first side and the size D4 of the second side satisfies: D3 / D4≥5, and the planar section is parallel to the first side, in the case that the pressure or temperature inside the battery monomer reaches a threshold value, the region where the first side is located is more prone to deformation, by setting the planar section parallel to the first side, to facilitate the deformation and cracking of the pressure relief part, so that the pressure relief part can be actuated in time to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0019] In some embodiments, the first wall is provided with a liquid injection hole penetrating through the first wall in the thickness direction of the first wall, the circular arc region includes a first sub-circular arc region away from the liquid injection hole, and the third inner recess is arranged in the planar region and close to the first sub-circular arc region.

[0020] In the embodiment of the present application, by arranging the liquid injection hole penetrating through the first wall along the thickness direction of the first wall, the circular arc region includes a first sub-circular arc region away from the liquid injection hole, and the third inner recess is arranged in the planar region and close to the first sub-circular arc region. On the one hand, in the case that the pressure or temperature inside the battery monomer reaches the threshold value, the third inner recess is arranged in the planar region and close to the first sub-circular arc region, which can effectively reduce the relative strength between the pressure relief part, the body part and the first protruding part, and in the case that the pressure or temperature inside the battery monomer reaches the threshold value, facilitate the deformation and cracking of the pressure relief part, so that the pressure relief part can be actuated in time to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer. On the other hand, in the process of injecting electrolyte into the battery monomer, the risk of electrolyte splashing into the second accommodating cavity can be reduced, thereby improving the use performance of the battery monomer.

[0021] In some embodiments, the battery monomer is a square battery monomer, the second accommodating cavity includes a planar segment and a circular arc segment in a plane perpendicular to the thickness direction of the first wall, and the first wall includes a first side and a second side perpendicular to each other, wherein the planar segment is parallel to the second side when the ratio between the size D3 of the first side and the size D4 of the second side satisfies D3 / D4≤3.

[0022] In the embodiment of the present application, by arranging the battery monomer as a square battery monomer, the second accommodating cavity includes a planar segment and a circular arc segment in a plane perpendicular to the thickness direction of the first wall, and the first wall includes a first side and a second side perpendicular to each other, wherein the planar segment is parallel to the second side when the ratio between the size D3 of the first side and the size D4 of the second side satisfies D3 / D4≤3, and in the case that the pressure or temperature inside the battery monomer reaches the threshold value, the region where the second side is located is more prone to deformation. By arranging the planar segment parallel to the second side, the deformation and cracking of the pressure relief part are facilitated, so that the pressure relief part can be actuated in time to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0023] In some embodiments, the first wall is provided with a liquid injection hole penetrating through the first wall along the thickness direction of the first wall, and the planar region includes a first sub-planar region away from the liquid injection hole, and the third inner recess is arranged in the first sub-planar region.

[0024] In the embodiments of the present application, by arranging the first wall to have the liquid injection hole penetrating through the first wall along the thickness direction of the first wall, and arranging the third inner recess in the first sub-planar area in the planar area away from the liquid injection hole, on the one hand, in the case that the pressure or temperature inside the battery monomer reaches the threshold value, the third inner recess arranged in the first sub-planar area in the planar area away from the liquid injection hole can effectively reduce the relative strength between the pressure relief part, the body part and the first protruding part, so as to facilitate the deformation and cracking of the pressure relief part in the case that the pressure or temperature inside the battery monomer reaches the threshold value, so that the pressure relief part can be actuated in time to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer, on the other hand, in the process of injecting electrolyte into the battery monomer, the risk of electrolyte splashing into the inside of the second accommodating cavity can be reduced, thereby improving the use performance of the battery monomer.

[0025] In some embodiments, the inner wall of the second accommodating cavity includes a planar area and a circular arc area, the planar area includes a first planar area and a second planar area opposite along a second direction, the third inner recess includes a third sub-inner recess and a fourth sub-inner recess, the third sub-inner recess is arranged in the first planar area, and the fourth sub-inner recess is arranged in the second planar area, and the second direction is perpendicular to the extension direction of the planar area.

[0026] In the embodiments of the present application, by arranging the inner wall of the second accommodating cavity to include a planar area and a circular arc area, the planar area includes a first planar area and a second planar area opposite along a second direction, and the third inner recess includes a third sub-inner recess and a fourth sub-inner recess, the third sub-inner recess is arranged in the first planar area, and the fourth sub-inner recess is arranged in the second planar area, in the case that the pressure or temperature inside the battery monomer reaches the threshold value, the third sub-inner recess arranged in the first planar area and the fourth sub-inner recess arranged in the second planar area can further reduce the relative strength between the pressure relief part, the body part and the first protruding part, so as to facilitate the deformation and cracking of the pressure relief part in the case that the pressure or temperature inside the battery monomer reaches the threshold value, so that the pressure relief part can be actuated in time to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0027] In some embodiments, the third sub-inner recess and the fourth sub-inner recess are respectively arranged symmetrically along a first direction, and the first direction is perpendicular to the second direction.

[0028] In the embodiments of the present application, by arranging the third sub-inner recess and the fourth sub-inner recess to be symmetrical along the first direction respectively, the relative strength between the pressure relief portion, the body portion and the first protruding portion can be further reduced, so that the deformation and cracking of the pressure relief portion can be facilitated when the pressure or temperature inside the battery monomer reaches the threshold value, and the pressure relief portion can be timely actuated to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer, and facilitating the processing and manufacturing of the battery monomer.

[0029] In some embodiments, the minimum dimension of the first inner recess, the second inner recess and the third inner recess along the thickness direction of the first wall is greater than or equal to 0.2 mm and less than or equal to 1 mm.

[0030] In the embodiments of the present application, by arranging the minimum dimension of the first inner recess, the second inner recess and the third inner recess along the thickness direction of the first wall to be greater than or equal to 0.2 mm and less than or equal to 1 mm, the structural strength of the pressure relief portion and the use performance of the pressure relief portion can be considered, so that the deformation and cracking of the pressure relief portion can be facilitated when the pressure or temperature inside the battery monomer reaches the threshold value, and the pressure relief portion can be timely actuated to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer, and facilitating the processing and manufacturing of the battery monomer.

[0031] In some embodiments, the battery monomer further comprises a protection member fixedly connected with the surface of the second accommodating cavity away from the electrode assembly, and the orthographic projection of the protection member covers the orthographic projection of the second accommodating cavity in the plane perpendicular to the thickness direction of the first wall.

[0032] In the embodiments of the present application, by arranging the battery monomer to comprise a protection member fixedly connected with the surface of the second accommodating cavity away from the electrode assembly, and the orthographic projection of the protection member covers the orthographic projection of the second accommodating cavity in the plane perpendicular to the thickness direction of the first wall, the protection effect on the pressure relief portion is improved, so as to reduce the risk of impurities or electrolyte splashing into the second accommodating cavity during the injection of electrolyte, and improve the use performance of the pressure relief portion.

[0033] In some embodiments, the first wall further comprises a second protruding portion protruding from the body portion in a direction away from the electrode assembly, the second protruding portion comprises a first groove with an opening away from the second accommodating cavity, and at least part of the protection member is accommodated in the first groove, and the orthographic projection of the protection member covers the orthographic projection of the second accommodating cavity in the plane perpendicular to the thickness direction of the first wall.

[0034] In this embodiment, the first wall is further provided with a second protrusion, which protrudes from the body portion in a direction away from the electrode assembly. The second protrusion includes a first groove with an opening away from the second receiving cavity. At least a portion of the protective member is accommodated in the first groove. On a plane perpendicular to the thickness direction of the first wall, the orthographic projection of the protective member covers the orthographic projection of the second receiving cavity. During the process of injecting electrolyte into the battery cell, the risk of electrolyte splashing into the second receiving cavity can be effectively reduced, thereby improving the performance of the battery cell.

[0035] In some embodiments, the protective member includes a main body and an extension that are connected to each other. The first wall is also provided with an injection hole that extends through the first wall along the thickness direction of the first wall. The extension is located between the injection hole and the second receiving cavity and is disposed close to the injection hole.

[0036] In this embodiment of the application, by setting the protective member as an interconnected main body and an extension, with the extension located between the injection hole and the second receiving cavity and close to the injection hole, the risk of electrolyte splashing into the second receiving cavity can be reduced during the process of injecting electrolyte into the battery cell, thereby improving the performance of the battery cell.

[0037] In some embodiments, the extension is disposed around the outer periphery of the second receiving cavity in a plane perpendicular to the thickness direction of the first wall.

[0038] In this embodiment of the application, by providing the extension around the outer periphery of the second receiving cavity on a plane perpendicular to the thickness direction of the first wall, the risk of electrolyte splashing into the second receiving cavity can be further reduced during the process of injecting electrolyte into the battery cell, thereby improving the performance of the battery cell.

[0039] In some embodiments, the extension is an annular structure, with the inner ring of the annular structure surrounding the outer periphery of the second receiving cavity. Thus, in this embodiment, by setting the extension as an annular structure, with the inner ring of the annular structure surrounding the outer periphery of the second receiving cavity, the risk of electrolyte splashing into the second receiving cavity can be further reduced during the injection of electrolyte into the battery cell, thereby improving the performance of the battery cell. Simultaneously, the extension has a simple structure, facilitating processing and manufacturing.

[0040] In some embodiments, the first wall is a bottom wall of the shell in the direction of gravity. In this way, in the embodiments of the present application, the deformation and cracking of the pressure relief portion on the first wall are facilitated in the case that the pressure or temperature inside the battery cell reaches a threshold value, so that the pressure relief portion can be actuated in time to discharge the high-temperature discharge inside the battery cell to the outside of the battery cell, thereby improving the use performance of the battery cell, and facilitating the processing and manufacturing of the battery cell.

[0041] In a second aspect, a battery device is provided, comprising: a plurality of battery cells, the battery cell being the battery cell in the first aspect or any implementation thereof.

[0042] In a third aspect, a power consuming device is provided, comprising the battery device in the second aspect, the battery device being configured to provide electric energy for the power consuming device.

[0043] In some implementations, the power consuming device can be a vehicle, a ship, a spacecraft, or the like.

[0044] In a fourth aspect, an energy storage device is provided, comprising the battery device in the second aspect, the battery device being configured to store electric energy for the energy storage device. BRIEF DESCRIPTION OF DRAWINGS

[0045] 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.

[0046] Figure 1 is a structural schematic diagram of a vehicle provided by an embodiment of the present application.

[0047] Figure 2 is a structural schematic diagram of a battery device provided by an embodiment of the present application.

[0048] Figure 3 is an exploded structural schematic diagram of a battery cell provided by an embodiment of the present application.

[0049] Figure 4 is an exploded structural schematic diagram of a battery cell provided by another embodiment of the present application.

[0050] Figure 5 is an exploded structural schematic diagram of an end cover provided by an embodiment of the present application.

[0051] Figure 6 is a cross-sectional schematic diagram of an end cover provided by an embodiment of the present application.

[0052] Figure 7 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0053] Figure 8 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0054] Figure 9 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0055] Figure 10 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0056] Figure 11 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0057] Figure 12 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0058] Figure 13 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0059] Figure 14 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0060] Figure 15 is a cross-sectional view of an end cap according to another embodiment of the present application.

[0061] Explanation of reference numerals: 1 - vehicle; 10 - battery device; 20 - battery cell; 30 - controller; 40 - motor; 11 - case; 111 - first structure; 112 - second structure; 112a - bottom plate; 112b - side plate; 21 - outer shell; 22 - electrode assembly; 211 - case; 212 - end cap; 2121 - positive rivet block; 2122 - positive upper plastic; 2123 - negative rivet block; 2124 - negative upper plastic; 2125 - support member; 213 - pressure relief portion; 222 - tab; 222a - positive tab; 222b - negative tab; 214 - electrode terminal; 214a - positive electrode terminal; 214b - negative electrode terminal; 23 - connecting member; 215 - first wall; 2151 - first surface; 2152 - second surface; 2153 - first protruding portion; 2154 - second protruding portion; 216 - liquid injection hole; 217 - first edge; 218 - second edge; 230 - body portion; 50 - first accommodating cavity; 60 - second accommodating cavity; 610 - flat section; 620 - circular arc section; 70 - inner wall; 710 - flat area; 711 - first flat area; 712 - second flat area; 720 - circular arc area; 721 - first circular arc area; 722 - second circular arc area; 730 - first sub-circular arc area; 740 - second sub-circular arc area; 80 - recessed portion; 810 - first recessed portion; 811 - first sub-recessed portion; 812 - second sub-recessed portion; 820 - second recessed portion; 830 - third recessed portion; 831 - third sub-recessed portion; 832 - fourth sub-recessed portion; 90 - protection member; 910 - body portion; 920 - extension portion; 930 - first groove.

[0062] In the drawings, the drawings are not drawn according to the actual proportions. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms used in disclosing the application, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The articles "a", "an", and "the" as used herein are to be construed to mean "at least one" or "one or more", unless otherwise indicated. The terms "comprise", "comprising", "comprises", "include", "including", and "includes" as used herein are to be construed as optionally permitting the presence of one or more elements, so long as the presence of the one or more elements does not change the basic function of the device or method to which the term refers. The terms "coupled" and "coupling" as used herein, mean the joining of two members together to form a single piece or unit, optionally with a third member interposed therebetween, and do not exclude the presence of an intermediate member between the two members. The terms "first", "second", "third", etc. as used herein are for distinguishing between similar elements and do not imply a particular order or sequence unless explicitly stated.

[0066] Reference throughout this application to "embodiment" 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 other embodiments. It is expressly understood that the application described herein is intended to encompass a wide variety of alternatives, modifications, and equivalents.

[0067] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, 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, it can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0068] The term "and / or" in the application is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the application generally represents that the front and rear associated objects have an "or" relationship.

[0069] In the embodiments of the application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0070] "Multiple" appearing in the application means more than two (including two), and similarly, "multiple groups" means more than two groups (including two groups), and "multiple pieces" means more than two pieces (including two pieces).

[0071] If not specifically stated, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0072] If not specifically stated, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0073] In some embodiments, 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.

[0074] As an example, the positive electrode current collector has two surfaces opposite 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.

[0075] As an example, the positive electrode current collector can adopt a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium, or silver, etc. can be adopted. The composite current collector can include a 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 polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0076] In some embodiments, the positive electrode can adopt 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, of course, the positive electrode active material can also be provided. As an example, the positive electrode active material is filled or / and deposited in the foamed metal.

[0077] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0078] As an example, the negative electrode current collector can adopt a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium, or silver, etc. can be adopted. The composite current collector can include a polymer material base layer and a metal layer. 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.).

[0079] As an example, the negative electrode sheet can include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0080] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two opposite surfaces of the negative electrode current collector.

[0081] As an example, the negative electrode active material can employ a negative electrode active material for a battery cell known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery cell can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0082] In some embodiments, the negative 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 a negative electrode sheet, the surface of the foamed metal can not be provided with a negative electrode active material, or can be provided with a negative electrode active material.

[0083] As an example, the negative electrode active material can be filled or / and deposited in the negative electrode current collector.

[0084] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0085] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0086] In some embodiments, the separator is a separator film. The type of the separator film is not particularly limited, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0087] As an 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. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive electrode and the negative electrode, or can be attached to the surface of the positive electrode and the negative electrode. An inorganic particle coating layer, an organic particle coating layer, or an organic / inorganic composite coating layer can be applied to the surface of the separator film.

[0088] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0089] In some embodiments, the battery cell further comprises an electrolyte, which functions to conduct ions between the positive electrode and the negative electrode. The type of electrolyte is not specifically limited in the present application, and can be selected as needed. The electrolyte can be liquid, gel, or solid.

[0090] In some embodiments, the liquid electrolyte comprises an electrolyte salt and a solvent.

[0091] In some embodiments, the electrolyte solution can optionally further comprise an additive. For example, the additive can comprise a negative electrode film-forming additive, a positive electrode film-forming additive, or an additive that improves certain properties of the battery cell, such as an additive that improves overcharge / fast charge performance, an additive that improves high-temperature performance, an additive that improves low-temperature performance, and the like.

[0092] In some embodiments, the gel electrolyte comprises a polymer as a backbone network, and can be used in combination with an ionic liquid-lithium salt.

[0093] In some embodiments, the solid-state electrolyte comprises a polymer solid-state electrolyte, an inorganic solid-state electrolyte, or a composite solid-state electrolyte.

[0094] As an example, the polymer of the polymer solid-state electrolyte can comprise polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single-ion polymer, a polyionic liquid, cellulose, or the like.

[0095] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid-state electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid-state electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorus sulfide, argyrodite), amorphous sulfide), a halide solid-state electrolyte, a nitride solid-state electrolyte, and a hydride solid-state electrolyte.

[0096] As an example, the composite solid-state electrolyte is formed by adding inorganic solid-state electrolyte fillers to a polymer solid-state electrolyte.

[0097] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of a wound structure and a stacked structure.

[0098] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0099] In some embodiments, the electrode assembly is a stacked structure.

[0100] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked.

[0101] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet is folded to form a plurality of folded segments which are stacked.

[0102] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded segments which are stacked.

[0103] As an example, a plurality of isolation pieces can be provided, and each isolation piece is provided between any adjacent positive electrode sheet or negative electrode sheet.

[0104] As an example, a plurality of isolation pieces can be provided, and each isolation piece is provided between any adjacent positive electrode sheet or negative electrode sheet.

[0105] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape.

[0106] In some embodiments, the electrode assembly can be provided with a tab, and the tab can guide current out of the electrode assembly. The tab can include a positive tab and a negative tab.

[0107] In some embodiments, the battery cell can include a housing. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a non-sealed structure, the housing serves to protect the electrode assembly, and the housing and the electrode assembly further include a sealing bag for encapsulating the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating piece or an aluminum-plastic film. When the housing is a sealed structure, the housing is used to encapsulate the electrode assembly and the electrolyte, etc.

[0108] 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 other shapes. The prismatic battery cell can include a square battery cell, a blade-shaped battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, etc. The present application is not particularly limited.

[0109] In some embodiments, at least one electrode terminal can be provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab or indirectly connected to the tab through a current collecting member. The electrode terminal can be provided on an end cover or on the housing.

[0110] In some embodiments, a pressure relief portion can be provided on the housing. The pressure relief portion is used to discharge internal gas of the battery cell.

[0111] As an example, the battery cell is actuated to release internal pressure or temperature when the internal pressure or temperature reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief portion performs an action or a weak structure provided in the pressure relief portion is broken, thereby forming an opening or passage for the internal pressure or temperature to be released. The threshold is designed differently according to design requirements. The threshold can depend on the material of one or more of the positive plate, the negative plate, the electrolyte, and the separator in the battery cell.

[0112] As an example, the pressure relief portion can be integrally formed with the housing.

[0113] As an example, the pressure relief portion can also be provided separately from the housing and connected thereto.

[0114] As referred to in the present application, "actuation" means that the pressure relief portion generates an action or is activated to a certain state, so that the internal pressure and temperature of the battery cell can be released. The action generated by the pressure relief portion can include, but is not limited to, movement of a component in the pressure relief portion to form an exhaust passage, at least a portion of the pressure relief portion being broken, shattered, torn, or opened, and the like. When the pressure relief portion is actuated, the high-temperature and high-pressure substances inside the battery cell are discharged as exhaust from the actuated portion. In this way, the battery cell can be released and cooled under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0115] In some embodiments, when the housing is a non-sealed structure, the pressure relief portion can be provided as a through hole for discharging gas inside the battery cell. In other embodiments, the pressure relief portion can also be referred to as a pressure relief mechanism.

[0116] As referred to in the present application, the exhaust from the battery cell includes, but is not limited to, electrolyte, dissolved or split positive and negative plates, fragments of the separator, high-temperature and high-pressure gas generated by reaction, flame, and the like.

[0117] As referred to in the embodiments of the present application, the battery device can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0118] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0119] As an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0120] In some embodiments, the battery device can be a battery pack including a box and one or more battery cell assemblies accommodated in the box.

[0121] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the case by fixing the battery module in the case.

[0122] As an example, the battery cell assembly can also be accommodated in the case by fixing a plurality of battery cells directly in the case.

[0123] As an example, the case can include a first case and a second case. The first case and the second case are fastened so that an enclosed space is formed inside the case to accommodate the battery cell assembly. Here, enclosed means covered or closed, which can be sealed or unsealed. The first case can be a top cover or a bottom plate.

[0124] As an example, the case can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are connected to the frame, respectively, so that an enclosed space is formed inside the case to accommodate the battery cell assembly.

[0125] In some embodiments, the case can be part of a chassis structure of a vehicle. For example, part of the case can be at least part of a floor of the vehicle, or part of the case can be at least part of a cross beam and a longitudinal beam of the vehicle.

[0126] The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery cells, such as mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships, and spacecraft, such as aircraft, rockets, space shuttles, and spacecraft.

[0127] The embodiments of the present application provide a power storage device including one or more battery clusters to improve the voltage and capacity of the power storage device. The battery cluster can include a plurality of battery devices connected in series by a busbar component to improve the voltage of the power storage device. When the power storage device includes a plurality of battery clusters, the plurality of battery clusters are connected in parallel to improve the capacity of the power storage device.

[0128] The power storage device can be used in a power storage power station, a wind power generation system, a solar power generation system, a mobile power system, or a temporary power supply system, etc. The power storage device can store electrical energy as needed and output electrical energy at an appropriate time. For example, the power storage device can store electrical energy during a low electricity usage period and provide electrical energy to related users or electric devices during a high electricity usage period. The power storage system provided by the embodiments of the present application can be any power system that needs to use a power storage device.

[0129] In some embodiments, the power storage device is a power storage container or a power storage cabinet.

[0130] In some embodiments, the power storage device can include a cabinet body and one or more battery clusters, and the battery clusters are accommodated in the cabinet body.

[0131] In some embodiments, the energy storage device can include a thermal management module, a master control module, a general control module, a power distribution module, a fire control module, and the like.

[0132] As an example, the thermal management module can include a liquid cooling unit that provides cooling liquid to each battery device through a pipeline for adjusting the temperature of the battery cell.

[0133] As an example, the master control module can serve as a battery management unit of the battery cluster for monitoring and managing the battery cluster. The master control module can monitor information such as current, voltage, power, or temperature of the battery cluster. For example, the charging and discharging current, voltage, and the like of the battery cluster can be controlled. The master control module includes an auxiliary battery management unit, a fuse module, and the like.

[0134] As an example, the general control module can serve as a battery management unit of the energy storage device for monitoring and managing the energy storage device. The general control module can monitor information such as current, voltage, power, state of charge, or temperature of the energy storage device. For example, the charging and discharging current, voltage, and the like of the energy storage device can be controlled. As an example, the general control module includes an insulation monitoring module, a main battery management unit, an Ethernet and optical fiber conversion module, and the like.

[0135] As an example, the fire control system includes a control panel, a detector, an alarm device, and the like for detecting, alarming, or extinguishing the energy storage system.

[0136] As an example, the power distribution device can be used to distribute power to the energy storage device power module.

[0137] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is an important factor in their development. In the development of battery technology, in addition to improving the electrical performance of the battery device, safety is also an issue that cannot be ignored. For example, in the case of high internal pressure or temperature of the battery cell, if the pressure relief portion cannot be actuated in time, it is easy to cause the deformation or rupture of the shell or internal structure of the battery cell, and at the same time, it is easy to cause thermal runaway of the battery cell, thereby reducing the safety of the battery cell. If the safety of the battery cell cannot be guaranteed, the battery cell cannot be used, which reduces the use performance of the battery cell. Therefore, how to improve the use performance of the battery cell has become a technical problem to be solved in the art.

[0138] Therefore, the application provides a battery monomer, a battery device, a power consumption device and an energy storage device. The battery monomer comprises an electrode assembly and a shell. The shell comprises a first accommodating cavity and a first wall. The electrode assembly is accommodated in the first accommodating cavity. The first wall comprises a body part, a first protruding part and a pressure relief part. The first protruding part protrudes from the body part in the direction of the electrode assembly. The first protruding part connects the body part and the pressure relief part. The pressure relief part is arranged on the side of the first protruding part close to the electrode assembly. The body part, the first protruding part and the pressure relief part enclose a second accommodating cavity with an opening away from the electrode assembly. An inner wall of the second accommodating cavity is provided with an inner recess. In this way, in the application, the shell of the battery monomer is provided with a first wall comprising a body part, a first protruding part and a pressure relief part. The first protruding part protrudes from the body part in the direction of the electrode assembly. The first protruding part connects the body part and the pressure relief part. The pressure relief part is arranged on the side of the first protruding part close to the electrode assembly. The body part, the first protruding part and the pressure relief part enclose a second accommodating cavity with an opening away from the electrode assembly. An inner wall of the second accommodating cavity is provided with an inner recess. The relative strength between the pressure relief part, the body part and the first protruding part is reduced. In the case that the pressure or temperature inside the battery monomer reaches a threshold value, the deformation and cracking of the pressure relief part are facilitated. The pressure relief part can be actuated in time to discharge the high-temperature discharge inside the battery monomer to the outside of the battery monomer, thereby improving the use performance of the battery monomer.

[0139] The technical solutions described in the application are applicable to various power consumption devices using battery devices.

[0140] 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. 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 machine, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling 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. The application does not specially limit the above power consumption devices.

[0141] It should be understood that the technical solutions described in the 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 taking the vehicle as an example for simplicity.

[0142] For example, as Figure 1The diagram shown is a structural schematic of a vehicle 1 according to one embodiment of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A motor 40, a controller 30, and a battery device 10 can be installed inside vehicle 1. The controller 30 controls the battery device 10 to supply power to the motor 40. For example, the battery device 10 can be installed at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1. For example, the battery device 10 can serve as the operating power source for vehicle 1, for example, to meet the electrical system requirements of vehicle 1, such as for starting, navigation, and operation. In another embodiment of this application, the battery device 10 can not only serve as the operating power source for vehicle 1, but also as the driving power source for vehicle 1, replacing or partially replacing gasoline or natural gas to provide driving power for vehicle 1.

[0143] To meet different power demands, the battery device 10 in this embodiment may include at least one battery cell assembly, which comprises multiple battery cells. These multiple battery cells can be electrically connected in series, parallel, or a combination thereof to form the battery device 10. A combination of series and parallel connections is used. The battery device 10 may also be referred to as a battery pack. For example, multiple battery cells can first be connected in series, parallel, or a combination to form a battery module, and then multiple battery modules can be connected in series, parallel, or a combination thereof to form the battery device 10. That is, multiple battery cells can directly form the battery device 10, or they can first be assembled into battery modules, and then the battery modules can be assembled into the battery device 10.

[0144] For example, such as Figure 2 The diagram shown is a structural schematic of a battery device 10 according to an embodiment of this application. The battery device 10 may include multiple battery cells 20. The battery device 10 may also include a housing 11 (or cover), which has a hollow interior structure, and the multiple battery cells 20 are housed within the housing 11. For example, the multiple battery cells 20 may be connected in parallel, series, or a mixed configuration and then placed inside the housing 11.

[0145] like Figure 2As shown, the box 11 can include two parts, here referred to as a first structure 111 and a second structure 112, which are buckled together. The shapes of the first structure 111 and the second structure 112 can be determined according to the shape of the combination of the plurality of battery monomers 20, and the first structure 111 and the second structure 112 can each have an opening. For example, the first structure 111 and the second structure 112 can each be a hollow cuboid and each have only one face as an opening face, the opening of the first structure 111 and the opening of the second structure 112 are oppositely arranged, and the first structure 111 and the second structure 112 are buckled to each other to form a box 11 with a closed cavity. Among them, the second structure 112 can include a bottom plate 112a, a side plate 112b and a beam. The plurality of battery monomers 20 are combined in parallel or in series or in a hybrid manner and placed in the box 11 formed after the buckling of the first structure 111 and the second structure 112.

[0146] Optionally, the battery device 10 can also include other structures, which will not be described one by one here. For example, the battery device 10 can also include a current collecting component for realizing the electrical connection between the plurality of battery monomers 20, such as parallel connection, series connection or hybrid connection. Specifically, the current collecting component can realize the electrical connection between the battery monomers 20 by connecting the electrode terminals of the battery monomers 20. Further, the current collecting component can be fixed to the electrode terminals of the battery monomers 20 by welding. The electrical energy of the plurality of battery monomers 20 can be further led out through the box by a conductive mechanism. Optionally, the conductive mechanism can also belong to the current collecting component.

[0147] According to different power requirements, the number of battery monomers 20 can be set to any value. The plurality of battery monomers 20 can be connected in series, parallel or hybrid manner to achieve larger capacity or power. Since the number of battery monomers 20 included in each battery device 10 can be large, in order to facilitate installation, the battery monomers 20 can be arranged in groups, and each group of battery monomers 20 forms a battery module. The number of battery monomers 20 included in the battery module is not limited and can be set according to requirements.

[0148] In the embodiments of the present application, according to different power requirements, the number of battery monomers 20 can be set to any value. The plurality of battery monomers 20 can be connected in series, parallel or hybrid manner to achieve larger capacity or power. Since the number of battery monomers 20 included in each battery device 10 can be large, in order to facilitate installation, the battery monomers 20 can be arranged in groups, and each group of battery monomers 20 forms a battery module. The number of battery monomers 20 included in the battery module is not limited and can be set according to requirements. The battery device 10 can include a plurality of battery modules, and these battery modules can be connected in series, parallel or hybrid manner.

[0149] Figure 3A structural diagram of a battery cell 20 is shown, Figure 4 A structural diagram of a battery cell 20 is shown, Figure 3 and Figure 4 As shown in FIGS. 1 and 2, the battery cell 20 can include a housing 21 having a closed accommodation space and an electrode assembly 22 disposed in the accommodation space of the housing 21. The housing 21 can include a shell 211 having at least one opening and an end cover 212 for being coupled with the shell 211 to form the housing 21 having the closed accommodation space.

[0150] It should be understood that the battery cell 20 in the embodiments of the present application can be a secondary battery, which refers to a battery cell 20 that can be activated by charging after discharging. For example, the battery cell 20 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc.

[0151] The electrode assembly 22 in the embodiments of the present application includes a positive electrode, a negative electrode, and a separator disposed between the negative electrode and the positive electrode. During the charging and discharging of the battery cell 20, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator disposed between the positive electrode and the negative electrode can prevent the positive and negative electrodes from short-circuiting while allowing the active ions to pass through.

[0152] In some embodiments, the end cover 212 can be a plate-shaped structure for covering the opening of the shell 211. In other embodiments, the end cover 212 has a similar structure to the shell 211, i.e., both the shell 211 and the end cover 212 are hollow structures having one opening, and the two openings are connected to form the housing 21 having the closed accommodation space.

[0153] It should be understood that if the end cover 212 is a plate-shaped structure, the shell 211 can be a hollow structure having one or more openings, for example, if the shell 211 is a hollow structure having one opening at one end, the end cover 212 can be one; if the shell 211 is a hollow structure having openings at opposite ends, the end cover 212 can be two, and the two end covers 212 cover the openings at the two ends of the shell 211, respectively.

[0154] The housing 21 can have various shapes, such as a cylinder, a cuboid, or other polyhedrons. For example, as shown in FIGS. 1 and 2, the housing 21 can be a cuboid structure. Figure 3 and Figure 4 As shown in FIGS. 1 and 2, the battery cell 20 in the embodiments of the present application is mainly described with the housing 21 as a cuboid structure.

[0155] It should be understood that the end cover 212 of the embodiments of the present application is used to cooperate with the shell 211 to isolate the internal environment of the battery monomer 20 from the external environment. The shape of the end cover 212 can be adapted to the shape of the shell 211, as shown in Figure 3 and Figure 4 The shell 211 is a cuboid structure and the end cover 212 is a rectangular plate structure adapted to the shell 211.

[0156] In some embodiments, the shell 211 can be a hollow structure with an opening formed at least at one end, and the shape of the end cover 212 can be adapted to the shape of the shell 211, and the end cover 212 is used to cover the opening of the shell 211, so that the shell 21 isolates the internal environment of the battery monomer 20 from the external environment. If the shell 211 is a hollow structure with an opening formed at one end, the end cover 212 can be provided as one.

[0157] The material of the shell 211 of the embodiments of the present application can include one or more, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cover 212 can also be one or more, such as copper, iron, aluminum, steel, aluminum alloy, etc. Among them, the material of the end cover 212 and the material of the shell 211 can be the same or different; the materials of different walls of the shell 211 can also be the same or different.

[0158] The end cover 212 of the embodiments of the present application can be any wall of the shell 21, for example, the end cover 212 can be the largest wall among the multiple walls included in the shell 21, or the smallest wall, or it can also be other walls, and the embodiments of the present application are not limited thereto. Or, the end cover 212 can also be other structures, for example, the end cover 212 can also be a groove structure with an opening to cover the opening of the shell 211, and the embodiments of the present application are not limited thereto.

[0159] It should be understood that the battery monomer 20 also includes an electrode terminal 214. The electrode terminal 214 of the embodiments of the present application is used to be electrically connected with the electrode assembly 22 inside the battery monomer 20 to output the electric energy of the battery monomer 20. As shown in Figure 3 to Figure 4As shown, the battery cell 20 can include at least two electrode terminals 214, which can include at least one positive electrode terminal 214a and at least one negative electrode terminal 214b, the positive electrode terminal 214a being configured to be electrically connected to the positive electrode tab 222a of the electrode assembly 22, and the negative electrode terminal 214b being configured to be electrically connected to the negative electrode tab 222b of the electrode assembly 22. The positive electrode terminal 214a can be directly connected to the positive electrode tab 222a, or can be indirectly connected to the positive electrode tab 222a, and the negative electrode terminal 214b can be directly connected to the negative electrode tab 222b, or can be indirectly connected to the negative electrode tab 222b. For example, the positive electrode terminal 214a can be electrically connected to the positive electrode tab 222a through a connecting member 23, and the negative electrode terminal 214b can be electrically connected to the negative electrode tab 222b through a connecting member 23. It should be understood that, in the embodiments of the present application, the positive electrode tab 222a and the negative electrode tab 222b can be collectively referred to as a tab 222.

[0160] In the embodiments of the present application, the walls of the shell 211 and the walls of the end cover 212 are collectively referred to as the walls of the battery cell 20, wherein the walls of the shell 211 include a bottom wall and four side walls for the cuboid-shaped battery cell 20 shown in FIGS. 1 to 3. Figure 3 and Figure 4 For the cuboid-shaped battery cell 20 shown in FIGS. 1 to 3, the walls of the shell 211 include a bottom wall and four side walls. The shell 211 is determined according to the shape of the combined one or more electrode assemblies 22, for example, the shell 211 can be a hollow cuboid or a square or a cylinder, and one of the faces of the shell 211 has an opening so that the one or more electrode assemblies 22 can be placed in the shell 211. For example, when the shell 211 is a hollow cuboid or a square, one of the planes of the shell 211 is an opening plane, i.e., the plane does not have a wall so that the inside and outside of the shell 211 are in communication. When the shell 211 can be a hollow cylinder, the end face of the shell 211 is an opening plane, i.e., the end face does not have a wall so that the inside and outside of the shell 211 are in communication. The end cover 212 covers the opening and is connected to the shell 211 to form a closed cavity in which the electrode assembly 22 is placed. The shell 211 is filled with an electrolyte, for example, an electrolyte solution.

[0161] In the battery cell 20, the electrode assembly 22 is a component in which an electrochemical reaction occurs in the battery cell 20, and according to actual use requirements, the electrode assembly 22 in the shell 211 can be one or multiple. For example, as shown in FIG. 1, the battery cell 20 is provided with one electrode assembly 22. Figure 4 As shown, the battery cell 20 is provided with two electrode assemblies 22. The electrode assembly 22 can be a cylinder, a cuboid, etc., and if the electrode assembly 22 is a cylindrical structure, the shell 211 can also be a cylindrical structure, and if the electrode assembly 22 is a cuboid structure, the shell 211 can also be a cuboid structure.

[0162] In the battery cell 20, the electrode assembly 22 is a component in which electrochemical reactions occur in the battery cell 20, and the electrode assembly 22 in the housing 211 can be one or multiple according to actual use requirements. For example, as shown in Figure 4 FIG. 1, two electrode assemblies 22 are arranged in the battery cell 20. The electrode assembly 22 can be a cylinder, a cuboid, etc. If the electrode assembly 22 is a cylinder structure, the housing 211 can also be a cylinder structure, and if the electrode assembly 22 is a cuboid structure, the housing 211 can also be a cuboid structure. In the embodiment of the present application, the material of the housing 211 can include the following materials: copper, iron, aluminum, steel, aluminum alloy, etc.

[0163] The battery cell 20 can also be provided with a pressure relief portion 213. The pressure relief portion 213 is used to actuate to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 20 reaches a threshold value.

[0164] The pressure relief portion 213 arranged on the battery cell 20 can be various possible pressure relief portions 213. For example, the pressure relief portion 213 can be a temperature-sensitive pressure relief portion configured to be able to melt when the internal temperature of the battery cell 20 provided with the pressure relief portion 213 reaches a threshold value; and / or, the pressure relief portion 213 can be a pressure-sensitive pressure relief portion configured to be able to break when the internal air pressure of the battery cell 20 provided with the pressure relief portion 213 reaches a threshold value.

[0165] In some implementations, the battery cell 20 can also be provided with an insulating member arranged in the accommodation space of the housing 211, and the insulating member can be a hollow structure with one end or multiple ends forming an opening, and the accommodation space in the hollow structure is used to accommodate the electrode assembly 22 to improve the insulation performance of the battery cell 20.

[0166] Figure 5 An exploded structural schematic diagram of the end cover 212 provided by an embodiment of the present application is shown.

[0167] As shown in Figure 5 , the surface of the end cover 212 on the side facing the electrode assembly 22 can be provided with a support member 2125, which can be a lower plastic. The support member 2125 covers the side of the end cover 212 facing the electrode assembly 22 as a whole to improve the impact resistance of the end cover 212.

[0168] The side of the positive electrode terminal 214a away from the electrode assembly 22 can be provided with a positive electrode upper plastic 2122 and a positive electrode riveting block 2121 in sequence to fix the positive electrode terminal 214a on the end cover 212, and the positive electrode upper plastic 2122 can seal and insulate the positive electrode terminal 214a. Correspondingly, the side of the negative electrode terminal 214b away from the electrode assembly 22 can be provided with a negative electrode upper plastic 2124 and a negative electrode riveting block 2123 in sequence to fix the negative electrode terminal 214b on the end cover 212, and the negative electrode upper plastic 2124 can seal and insulate the negative electrode terminal 214b.

[0169] Figure 6 A cross-sectional view of the end cover 212 is shown. Figure 7 A cross-sectional view of the end cover 212 is shown. Figure 8 A cross-sectional view of the end cover 212 is shown.

[0170] In some implementations, as shown in Figure 6 to Figure 8 The battery cell 20 includes an electrode assembly 22 and a shell 21, the shell 21 includes a first accommodating cavity 50 and a first wall 215, the electrode assembly 22 is accommodated in the first accommodating cavity 50, the first wall 215 includes a body part 230, a first protruding part 2153 protruding from the body part 230 towards the electrode assembly 22, and a pressure relief part 213 connected to the body part 230 and the first protruding part 2153, the pressure relief part 213 is arranged on the side of the first protruding part 2153 close to the electrode assembly 22, and the body part 230, the first protruding part 2153 and the pressure relief part 213 form a second accommodating cavity 60 with an opening away from the electrode assembly 22; wherein the inner wall 70 of the second accommodating cavity 60 is provided with an inner recess 80.

[0171] It should be understood that the battery cell 20 of the embodiments of the present application can be a polyhedral structure of any shape, i.e. the battery cell 20 can include a plurality of walls, the first wall 215 is any one wall of the battery cell 20, and correspondingly, the pressure relief part 213 can be located on any one wall of the battery cell 20. It should also be understood that Figure 7 and Figure 8 The direction Z shown in the above and the direction Z shown in the above can be the thickness direction of the first wall 215, the direction X is perpendicular to the thickness direction of the first wall 215, and the direction Y is perpendicular to the thickness direction of the first wall 215.

[0172] Exemplarily, the first wall 215 includes but is not limited to the following examples: the first wall 215 can be the wall with the smallest area of the battery cell 20; the first wall 215 can also be the wall with the largest area of the battery cell 20; the first wall 215 can be the wall provided with the electrode terminal 214 of the battery cell 20; the first wall 215 can be the wall adjacent to the wall provided with the electrode terminal 214 of the battery cell 20; the first wall 215 can be the wall opposite to the wall provided with the electrode terminal 214 of the battery cell 20.

[0173] It should also be understood that the body portion 230, the first protruding portion 2153 and the pressure relief portion 213 enclose a second accommodating cavity 60 with an opening away from the electrode assembly 22. The shape of the opening of the second accommodating cavity 60 in a plane perpendicular to the thickness direction of the first wall 215 can be set according to actual needs. For example, in a plane perpendicular to the thickness direction of the first wall 215, the shape of the opening of the second accommodating cavity 60 can be circular, oval, polygonal, rectangular, etc. The embodiments of the present application are not limited as examples.

[0174] It should also be understood that the body portion 230 and the first protruding portion 2513 can be integrally formed or separately formed. For example, the body portion 230 and the first protruding portion 2513 can be integrally formed by stamping. The pressure relief portion 213 can be arranged on the side of the first protruding portion 2513 close to the first accommodating cavity 50, so that the first protruding portion 2513, the pressure relief portion 213 and the body portion 230 enclose a second accommodating cavity 60 with an opening away from the electrode assembly 22.

[0175] It should also be understood that the pressure relief portion 213 of the embodiments of the present application refers to an element or component that is actuated when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold value to release the internal pressure or temperature. The threshold value is designed differently according to different design needs. The threshold value can depend on the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolyte and the separator in the battery cell 20.

[0176] The "actuation" mentioned in the present application refers to the action of the pressure relief portion 213 or the activation of the pressure relief portion 213 to a certain state, so that the internal pressure and temperature of the battery cell 20 can be released. The action of the pressure relief portion 213 can include but is not limited to at least one of the following: the pressure relief portion 213 is broken, cracked, torn or opened, etc. During the actuation of the pressure relief portion 213, the high-temperature and high-pressure substances inside the battery cell 20 are discharged outward from the actuated part as exhaust. In this way, the battery cell 20 can be relieved of pressure and temperature in a controllable manner, thereby avoiding potential more serious accidents.

[0177] The emissions from the battery monomer 20 mentioned in the embodiments of the present application include, but are not limited to, electrolyte, dissolved or split positive and negative electrode sheets, fragments of the separator film, high-temperature and high-pressure gas generated by reaction, flame, etc.

[0178] It should also be understood that the shape of the inner recess 80 provided on the inner wall 70 of the second accommodating cavity 60 can be set according to actual needs. For example, the inner recess 80 can be provided as a groove-shaped structure as shown in the middle. It should also be understood that the number of inner recesses 80 provided on the inner wall 70 of the second accommodating cavity 60 can be set according to actual needs. In the case of providing a plurality of inner recesses 80 on the inner wall 70 of the second accommodating cavity 60, the plurality of inner recesses 80 can be arranged in any direction on the surface of the inner wall 70 facing the first accommodating cavity 50. For example, the plurality of inner recesses 80 can be arranged in a stepped manner in the thickness direction of the first wall 215. Figure 7

[0179] It should also be understood that, as shown in Figure 7 and Figure 8 , the first wall 215 includes a first surface 2151 facing the first accommodating cavity 50 and a second surface 2152 facing away from the first accommodating cavity 50. The portion of the first surface 2151 around the outer periphery of the second accommodating cavity 60 facing the first accommodating cavity 50 can protrude in the direction of the first accommodating cavity 50 to form a first protruding portion 2153. The height H1 of the first protruding portion 2153 protruding compared to the first surface 2151 can be set to 1mm≤H1≤3mm. For example, the height H1 of the first protruding portion 2153 protruding compared to the first surface 2151 can be set to 1mm, 1.5mm, 2mm, 2.5mm, 3mm, etc., or a value within the range obtained by combining any two of the above values. In some implementations, the height H1 of the first protruding portion 2153 protruding compared to the first surface 2151 can also be set to 1.5mm≤H1≤2mm.

[0180] ​In the embodiments of the present application, by setting the shell 21 of the battery monomer 20 to include a first wall 215, the first wall 215 includes a body part 230, a first protruding part 2153 protruding from the body part 230 towards the electrode assembly 22, and a pressure relief part 213 connected to the body part 230 and the first protruding part 2153, the pressure relief part 213 is arranged on the side of the first protruding part 2153 close to the electrode assembly 22, the body part 230, the first protruding part 2153 and the pressure relief part 213 enclose a second containing cavity 60 with an opening away from the electrode assembly 22, and the inner wall 70 of the second containing cavity 60 is provided with an inner recess 80 to reduce the relative strength between the pressure relief part 213, the body part 230 and the first protruding part 2153, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, so as to facilitate the deformation and cracking of the pressure relief part 213, so that the pressure relief part 213 can act in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0181] In some implementations, as shown in Figure 6 to Figure 8 the inner wall 70 of the second containing cavity 60 includes a planar region 710 and a circular arc region 720, and the inner recess 80 includes a first inner recess 810 arranged in the circular arc region 720.

[0182] Exemplarily, as shown in Figure 6 the inner wall 70 of the second containing cavity 60 can include two circular arc regions 720 opposite in the direction X, and two planar regions 710 opposite in the direction Y. During the actuation of the pressure relief part 213, the circular arc region 720 is more susceptible to greater stress concentration than the planar region 710, so that the possibility of deformation is higher, and arranging the inner recess 80 in the circular arc region 720 can effectively reduce the relative strength between the pressure relief part 213, the body part 230 and the first protruding part 2153, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, so as to facilitate the deformation and cracking of the pressure relief part 213.

[0183] It should also be understood that the first inner recess 810 in the inner recess 80 arranged in the circular arc region 720 can mean that the orthographic projection of the circular arc region 720 can cover the orthographic projection of the first inner recess 810 in the plane perpendicular to the thickness direction of the first wall 215.

[0184] In the embodiment of the present application, by setting the inner wall 70 of the second accommodating cavity 60 to include a planar region 710 and a circular-arc region 720, and the inner recess 80 includes a first inner recess 810, and the first inner recess 810 is arranged at the circular-arc region 720, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the first inner recess 810 arranged at the circular-arc region 720 effectively reduces the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, facilitates the deformation and cracking of the pressure relief portion 213, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0185] In some implementations, as shown in FIG. 8, the circular-arc region 720 includes a first circular-arc region 721 and a second circular-arc region 722 opposite along a first direction, the first inner recess 810 includes a first sub-inner recess 811 and a second sub-inner recess 812, the first sub-inner recess 811 is arranged at the first circular-arc region 721, and the second sub-inner recess 812 is arranged at the second circular-arc region 722, and the first direction is the extension direction of the planar region 710. Figure 6 to Figure 8 It should be understood that the above-mentioned first direction can be the direction X shown in FIG. 8. It should also be understood that the shape and number of the first sub-inner recess 811 arranged at the first circular-arc region 721 can be set according to actual needs, and the shape and number of the second sub-inner recess 812 arranged at the second circular-arc region 722 can be set according to actual needs.

[0186] Figure 6 In the embodiment of the present application, by setting the circular-arc region 720 to include a first circular-arc region 721 and a second circular-arc region 722 opposite along a first direction, the first inner recess 810 includes a first sub-inner recess 811 and a second sub-inner recess 812, the first sub-inner recess 811 is arranged at the first circular-arc region 721, and the second sub-inner recess 812 is arranged at the second circular-arc region 722, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the first sub-inner recess 811 is arranged at the first circular-arc region 721, and the second sub-inner recess 812 is arranged at the second circular-arc region 722, which can further reduce the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, facilitates the deformation and cracking of the pressure relief portion 213, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0187] In the embodiment of the present application, by setting the circular-arc region 720 to include a first circular-arc region 721 and a second circular-arc region 722 opposite along a first direction, the first inner recess 810 includes a first sub-inner recess 811 and a second sub-inner recess 812, the first sub-inner recess 811 is arranged at the first circular-arc region 721, and the second sub-inner recess 812 is arranged at the second circular-arc region 722, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the first sub-inner recess 811 is arranged at the first circular-arc region 721, and the second sub-inner recess 812 is arranged at the second circular-arc region 722, which can further reduce the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, facilitates the deformation and cracking of the pressure relief portion 213, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0188] ​In some implementations, as shown in FIG. 8, the first sub-internal recess 811 and the second sub-internal recess 812 are respectively symmetrically arranged along a second direction, which is perpendicular to the first direction. Figure 6 to Figure 8

[0189] It should be understood that the second direction can be the direction Y shown in FIG. 8. For example, the first sub-internal recess 811 and the second sub-internal recess 812 can be respectively symmetrically arranged along the direction Y-axis, which facilitates the processing and manufacturing of the first wall 215. Figure 6

[0190] In the embodiments of the present application, by respectively symmetrically arranging the first sub-internal recess 811 and the second sub-internal recess 812 along the second direction, the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153 can be further reduced, which facilitates the deformation and cracking of the pressure relief portion 213 when the pressure or temperature inside the battery monomer 20 reaches a threshold value, so that the pressure relief portion 213 can be timely actuated to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20, and facilitating the processing and manufacturing of the battery monomer 20.

[0191] Figure 9 FIG. 9 shows a cross-sectional schematic view of an end cover 212 provided by another embodiment of the present application.

[0192] In some implementations, as shown in FIG. 8, the first sub-internal recess 811 and the second sub-internal recess 812 are respectively symmetrically arranged along a second direction, which is perpendicular to the first direction. Figure 9

[0193] It should be understood that the second direction can be the direction Y shown in FIG. 8. For example, the first sub-internal recess 811 and the second sub-internal recess 812 can be respectively symmetrically arranged along the direction Y-axis, which facilitates the processing and manufacturing of the first wall 215.

[0194] ​​​In the embodiments of the present application, by setting the inner recess 80 to further include a second inner recess 820, the second inner recess 820 is arranged on the planar region 710 and close to the circular arc region 720, in the case that the pressure or temperature inside the battery monomer 20 reaches the threshold value, the second inner recess 820 arranged on the planar region 710 and close to the circular arc region 720 can effectively reduce the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153, in the case that the pressure or temperature inside the battery monomer 20 reaches the threshold value, in order to facilitate the deformation and cracking of the pressure relief portion 213, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0195] Figure 10 A cross-sectional view of the end cover 212 provided by another embodiment of the present application is shown. Figure 11 A cross-sectional view of the end cover 212 provided by another embodiment of the present application is shown. Figure 12 A cross-sectional view of the end cover 212 provided by another embodiment of the present application is shown. Figure 13 A cross-sectional view of the end cover 212 provided by another embodiment of the present application is shown.

[0196] In some implementations, as Figure 10 to Figure 13 shown, the inner recess 80 further includes a third inner recess 830, and the surface of the second accommodating cavity 60 away from the electrode assembly 22 is provided with the third inner recess 830.

[0197] It should be understood that the shape and number of the third inner recess 830 arranged on the surface of the second accommodating cavity 60 away from the electrode assembly 22 can be set according to actual needs. For example, the third inner recess 830 can be arranged as a groove structure with the opening away from the electrode assembly 22, as Figure 12 shown, the surface of the second accommodating cavity 60 away from the electrode assembly 22 can be provided with four third inner recesses 830.

[0198] In the embodiments of the present application, by setting the inner recess 80 to further include a third inner recess 830, the surface of the second accommodating cavity 60 away from the electrode assembly 22 is provided with the third inner recess 830, which is arranged on the surface of the second accommodating cavity 60 away from the electrode assembly 22, and in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153 can be effectively reduced, so as to facilitate the deformation and cracking of the pressure relief portion 213 in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0199] In some embodiments, as shown in Figure 10 the battery monomer 20 is a square battery monomer, and in the plane perpendicular to the thickness direction of the first wall 215, the second accommodating cavity 60 includes a planar section 610 and a circular arc section 620, and the first wall 215 includes a first edge 217 and a second edge 218 perpendicular to each other, wherein the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies: D3 / D4≥5, and the planar section 610 is parallel to the first edge 217.

[0200] It should be understood that in the embodiments of the present application, in the case that the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies: D3 / D4≥5, since the size of the first edge 217 is relatively long, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the area where the first edge 217 of the battery monomer 20 is located is more prone to deformation, and by arranging the planar section 610 parallel to the first edge 217, i.e. arranging the pressure relief portion 213 in a horizontal state, the deformation and cracking of the pressure relief portion 213 can be facilitated. Exemplarily, the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies: D3 / D4≥5, and in the case that the size D4 of the second edge 218 is less than or equal to 30 mm, the pressure relief portion 213 can be arranged in a horizontal state.

[0201] Exemplarily, the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 can be set to: 5, 6, 7, 8, 9, 10, 11, 12, etc., or a value within the range obtained by any two of the above combinations.

[0202] In the embodiment of the present application, by setting the battery monomer 20 as a square battery monomer, in the plane perpendicular to the thickness direction of the first wall 215, the second accommodating cavity 60 comprises a planar section 610 and a circular arc section 620, the first wall 215 comprises a first edge 217 and a second edge 218 perpendicular to each other, and the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies: D3 / D4≥5. In the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the area where the first edge 217 is located is more prone to deformation. By arranging the planar section 610 parallel to the first edge 217, the deformation and cracking of the pressure relief portion 213 are facilitated, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0203] In some implementations, as shown in Figure 10 The first wall 215 is provided with a liquid injection hole 216 penetrating through the first wall 215 in the thickness direction of the first wall 215, the circular arc region 720 comprises a first sub-circular arc region 730 away from the liquid injection hole 216, and the third inner recess 830 is arranged in the planar region 710 and close to the first sub-circular arc region 730.

[0204] It should be understood that the circular arc region 720 comprises a first sub-circular arc region 730 away from the liquid injection hole 216 and a second sub-circular arc region 740 close to the liquid injection hole 216, and the third inner recess 830 is arranged in the first sub-circular arc region 730.

[0205] In the embodiment of the present application, by arranging the first wall 215 with a liquid injection hole 216 penetrating through the first wall 215 in the thickness direction of the first wall 215, the circular arc region 720 comprises a first sub-circular arc region 730 away from the liquid injection hole 216, and the third inner recess 830 is arranged in the planar region 710 and close to the first sub-circular arc region 730. On the one hand, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the third inner recess 830 is arranged in the planar region 710 and close to the first sub-circular arc region 730, which can effectively reduce the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153. In the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the deformation and cracking of the pressure relief portion 213 are facilitated, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20. On the other hand, in the process of injecting electrolyte into the battery monomer 20, the risk of electrolyte splashing into the inside of the second accommodating cavity 60 can be reduced, thereby improving the use performance of the battery monomer 20.

[0206] In some embodiments, as shown in FIG. 6, the battery cell 20 is a square battery cell, and the second accommodating cavity 60 includes a planar section 610 and a circular arc section 620 in a plane perpendicular to the thickness direction of the first wall 215, and the first wall 215 includes a first edge 217 and a second edge 218 perpendicular to each other, wherein, when the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies D3 / D4≤3, the planar section 610 is parallel to the second edge 218.

[0207] In some embodiments, as shown in FIG. 6, the battery cell 20 is a square battery cell, and the second accommodating cavity 60 includes a planar section 610 and a circular arc section 620 in a plane perpendicular to the thickness direction of the first wall 215, and the first wall 215 includes a first edge 217 and a second edge 218 perpendicular to each other, wherein, when the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies D3 / D4≤3, the planar section 610 is parallel to the second edge 218. Figure 10

[0208] It should be understood that, in the embodiments of the present application, when the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies D3 / D4≤3, since the size of the second edge 218 is relatively long, when the pressure or temperature inside the battery cell 20 reaches a threshold value, the area where the second edge 218 of the battery cell 20 is located is more prone to deformation, and by arranging the planar section 610 parallel to the second edge 218, i.e., arranging the pressure relief portion 213 in a vertical state, the deformation and cracking of the pressure relief portion 213 are facilitated. For example, when the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies D3 / D4≤3, and the size D3 of the first edge 217 is less than or equal to 150 mm, the pressure relief portion 213 can be arranged in a vertical state. For another example, when the area of the pressure relief portion 213 in a plane perpendicular to the thickness direction of the first wall 215 is greater than or equal to 860 mm 2 , the pressure relief portion 213 can be arranged in a vertical state.

[0209] For example, the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 can be set to 1, 1.5, 2, 2.5, 3, etc., or a value within the range obtained by any two of the above combinations.

[0210] ​In the embodiment of the present application, by setting the battery monomer 20 as a square battery monomer, in the plane perpendicular to the thickness direction of the first wall 215, the second accommodating cavity 60 comprises a planar section 610 and a circular arc section 620, and the first wall 215 comprises a first edge 217 and a second edge 218 perpendicular to each other, wherein the ratio between the size D3 of the first edge 217 and the size D4 of the second edge 218 satisfies: D3 / D4≤3, the planar section 610 is parallel to the second edge 218, and the area where the second edge 218 is located is more prone to deformation when the pressure or temperature inside the battery monomer 20 reaches a threshold value. By setting the planar section 610 parallel to the second edge 218, the deformation and cracking of the pressure relief portion 213 are facilitated, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0211] In some embodiments, the first wall 215 is provided with a liquid injection hole 216 penetrating through the first wall 215 in the thickness direction of the first wall 215, the planar region 710 comprises a first sub-planar region 750 away from the liquid injection hole 216, and the third inner recess 830 is arranged in the first sub-planar region 750.

[0212] It should be understood that the planar region 710 comprises a first sub-planar region 750 away from the liquid injection hole 216 and a second sub-planar region 760 close to the liquid injection hole 216, and the third inner recess 830 is arranged in the first sub-planar region 750.

[0213] In the embodiment of the present application, by setting the first wall 215 to be provided with a liquid injection hole 216 penetrating through the first wall 215 in the thickness direction of the first wall 215, and arranging the third inner recess 830 in the first sub-planar region 750 away from the liquid injection hole 216 in the planar region 710, on the one hand, when the pressure or temperature inside the battery monomer 20 reaches a threshold value, the third inner recess 830 is arranged in the first sub-planar region 750 away from the liquid injection hole 216 in the planar region 710, which can effectively reduce the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153, facilitate the deformation and cracking of the pressure relief portion 213 when the pressure or temperature inside the battery monomer 20 reaches a threshold value, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20, on the other hand, during the process of injecting electrolyte into the battery monomer 20, the risk of electrolyte splashing into the inside of the second accommodating cavity 60 can be reduced, thereby improving the use performance of the battery monomer 20.

[0214] In some implementations, as Figure 12As shown, the inner wall 70 of the second accommodating cavity 60 includes a planar region 710 and a circular arc region 720, the planar region 710 includes a first planar region 711 and a second planar region 712 opposite along a second direction, the third inner recess 830 includes a third sub-inner recess 831 and a fourth sub-inner recess 832, the third sub-inner recess 831 is arranged at the first planar region 711, and the fourth sub-inner recess 832 is arranged at the second planar region 712, the second direction is perpendicular to an extension direction of the planar region 710.

[0215] It should be understood that the first planar region 711 and the second planar region 712 in the embodiments of the present application can be respectively arranged symmetrically along the direction Y. It should also be understood that the shape and number of the third sub-inner recess 831 arranged at the first planar region 711 can be set according to actual needs, and the shape and number of the fourth sub-inner recess 832 arranged at the second planar region 712 can be set according to actual needs.

[0216] In the embodiments of the present application, by arranging the inner wall 70 of the second accommodating cavity 60 to include a planar region 710 and a circular arc region 720, the planar region 710 includes a first planar region 711 and a second planar region 712 opposite along the second direction, and the third inner recess 830 includes a third sub-inner recess 831 and a fourth sub-inner recess 832, the third sub-inner recess 831 is arranged at the first planar region 711, and the fourth sub-inner recess 832 is arranged at the second planar region 712, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the third sub-inner recess 831 is arranged at the first planar region 711, and the fourth sub-inner recess 832 is arranged at the second planar region 712, which can further reduce the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, to facilitate the deformation and cracking of the pressure relief portion 213, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20.

[0217] In some implementations, as shown, Figure 12 As shown, the third sub-inner recess 831 and the fourth sub-inner recess 832 are respectively arranged symmetrically along a first direction, and the first direction is perpendicular to the second direction.

[0218] Exemplarily, the third sub-inner recess 831 and the fourth sub-inner recess 832 can be respectively arranged symmetrically along the direction X axis, and facilitate the processing and manufacturing of the first wall 215.

[0219] In the embodiments of the present application, by respectively arranging the third sub-inner recess 831 and the fourth sub-inner recess 832 symmetrically along the first direction, the relative strength between the pressure relief portion 213, the body portion 230 and the first protruding portion 2153 can be further reduced, so that the deformation and cracking of the pressure relief portion 213 are facilitated when the pressure or temperature inside the battery monomer 20 reaches the threshold value, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20, and facilitating the processing and manufacturing of the battery monomer 20.

[0220] In some implementations, as shown in Figure 8 and Figure 13 The minimum size of the first inner recess 810, the second inner recess 820 and the third inner recess 830 in the thickness direction of the first wall 215 is greater than or equal to 0.2mm and less than or equal to 1mm.

[0221] Exemplarily, the value of the minimum size D1 of the first inner recess 810 in the thickness direction of the first wall 215 can be set to 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., or a value within the range obtained by any two of the above value combinations.

[0222] Exemplarily, the value of the minimum size (not shown in the figure) of the second inner recess 820 in the thickness direction of the first wall 215 can be set to 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., or a value within the range obtained by any two of the above value combinations.

[0223] Exemplarily, the value of the minimum size D2 of the third inner recess 830 in the thickness direction of the first wall 215 can be set to 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc., or a value within the range obtained by any two of the above value combinations.

[0224] In the embodiments of the present application, by setting the minimum size of the first inner recess 810, the second inner recess 820 and the third inner recess 830 along the thickness direction of the first wall 215 to be greater than or equal to 0.2 mm and less than or equal to 1 mm, the structural strength and the use performance of the pressure relief portion 213 are considered, in the case that the pressure or temperature inside the battery monomer 20 reaches the threshold value, the deformation and cracking of the pressure relief portion 213 are facilitated, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20, and facilitating the processing and manufacturing of the battery monomer 20.

[0225] In some implementations, as shown in Figure 5 , Figure 7 , Figure 8 and Figure 13 , the battery monomer 20 further comprises a protective piece 90 fixedly connected with the surface of the second accommodating cavity 60 away from the electrode assembly 22, and the orthographic projection of the protective piece 90 covers the orthographic projection of the second accommodating cavity 60 in the plane perpendicular to the thickness direction of the first wall 215.

[0226] It should be understood that the orthographic projection of the protective piece 90 in the embodiments of the present application covers the orthographic projection of the second accommodating cavity 60 in the plane perpendicular to the thickness direction of the first wall 215, so as to protect the pressure relief portion 213 inside the second accommodating cavity 60, thereby reducing the risk of impurities or foreign objects falling into the area where the pressure relief portion 213 is located, and improving the use stability of the pressure relief portion 213. The material of the protective piece 90 includes but is not limited to plastic, rubber or silicone, etc. The shape of the protective piece 90 can be set according to actual needs, for example, the shape of the protective piece 90 can be set according to the shape of the opening of the second accommodating cavity 60.

[0227] In the embodiments of the present application, by setting the protective piece 90 fixedly connected with the surface of the second accommodating cavity 60 away from the electrode assembly 22 in the battery monomer 20, the orthographic projection of the protective piece 90 covers the orthographic projection of the second accommodating cavity 60 in the plane perpendicular to the thickness direction of the first wall 215, thereby improving the protection of the pressure relief portion 213, reducing the risk of impurities or electrolyte splashing into the second accommodating cavity 60 during the electrolyte injection process, and improving the use performance of the pressure relief portion 213.

[0228] In some implementations, as shown in Figure 7 , Figure 8 and Figure 13As shown, the first wall 215 further comprises a second protruding portion 2154 protruding from the body portion 230 in a direction away from the electrode assembly 22, the second protruding portion 2154 comprises a first groove 930 opening away from the second accommodating cavity 60, at least part of the protective member 90 is accommodated in the first groove 930, and a projection of the protective member 90 on a plane perpendicular to a thickness direction of the first wall 215 covers a projection of the second accommodating cavity 60.

[0229] It should be understood that a part of the second surface 2152 surrounding an outer periphery of the second accommodating cavity 60 away from the first accommodating cavity 50 can be formed as a second protruding portion 2154 protruding in a direction away from the first accommodating cavity 50, a height H2 of the second protruding portion 2154 protruding relative to the second surface 2152 can be set as: 0.2mm≤H2≤0.5mm. Exemplarily, a value of the height H2 of the second protruding portion 2154 protruding relative to the second surface 2152 can be set as: 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc., or a value within a range obtained by any two of the above combinations.

[0230] It should be further understood that a bottom wall of the first groove 930 is in communication with the second accommodating cavity 60, a projection of the protective member 90 on a plane perpendicular to a thickness direction of the first wall 215 covers a projection of the second accommodating cavity 60, so as to reduce a risk of electrolyte splashing into the second accommodating cavity 60 and other impurities falling into the second accommodating cavity 60, thereby improving a use performance of the battery monomer 20.

[0231] In the embodiment of the present application, the first wall 215 further comprises a second protruding portion 2154 protruding from the body portion 230 in a direction away from the electrode assembly 22, the second protruding portion 2154 comprises a first groove 930 opening away from the second accommodating cavity 60, at least part of the protective member 90 is accommodated in the first groove 930, and a projection of the protective member 90 on a plane perpendicular to a thickness direction of the first wall 215 covers a projection of the second accommodating cavity 60, so as to effectively reduce a risk of electrolyte splashing into the second accommodating cavity 60 during injection of electrolyte into the battery monomer 20, thereby improving a use performance of the battery monomer 20.

[0232] Figure 14 A cross-sectional view of an end cover 212 provided by another embodiment of the present application is shown. Figure 15 A cross-sectional view of an end cover 212 provided by another embodiment of the present application is shown. Exemplarily, the end cover 212 can be a cross-sectional view of the end cover 212 on an XOY cross-section. Figure 14 The end cover 212 can be a cross-sectional view of the end cover 212 on an XOZ cross-section. Figure 15 The end cover 212 can be a cross-sectional view of the end cover 212 on an XOY cross-section.

[0233] In some implementations, as shown in Figs. 9A and 9B, the protection member 90 includes a main body portion 910 and an extension portion 920 connected to each other, and the first wall 215 is further provided with a liquid injection hole 216 penetrating the first wall 215 along the thickness direction of the first wall 215, and the extension portion 920 is located between the liquid injection hole 216 and the second accommodating cavity 60 and arranged close to the liquid injection hole 216. Figure 14 Figure 15 In some implementations, as shown in Figs. 9A and 9B, the protection member 90 includes a main body portion 910 and an extension portion 920 connected to each other, and the first wall 215 is further provided with a liquid injection hole 216 penetrating the first wall 215 along the thickness direction of the first wall 215, and the extension portion 920 is located between the liquid injection hole 216 and the second accommodating cavity 60 and arranged close to the liquid injection hole 216.

[0234] It should be understood that the main body portion 910 and the extension portion 920 in the protection member 90 in the embodiments of the present application can be fixedly connected or movably connected, and in the case of fixed connection between the main body portion 910 and the extension portion 920, the main body portion 910 and the extension portion 920 can be connected by welding or adhesion.

[0235] It should be further understood that the extension portion 920 can be located between the liquid injection hole 216 and the second accommodating cavity 60 and arranged close to the liquid injection hole 216, which means that the extension portion 920 can be arranged between the liquid injection hole 216 and the second accommodating cavity 60, so that the extension portion 920 can block the risk of electrolyte splashing into the second accommodating cavity 60 during the process of injecting electrolyte into the battery monomer 20.

[0236] It should be further understood that in the plane perpendicular to the thickness direction of the first wall 215, the extension portion 920 can be arranged in a continuous structure or an intermittent structure, which is not limited in the embodiments of the present application.

[0237] In the embodiments of the present application, by arranging the protection member 90 as the main body portion 910 and the extension portion 920 connected to each other, and arranging the extension portion 920 between the liquid injection hole 216 and the second accommodating cavity 60 and close to the liquid injection hole 216, the risk of electrolyte splashing into the second accommodating cavity 60 during the process of injecting electrolyte into the battery monomer 20 can be reduced, thereby improving the use performance of the battery monomer 20.

[0238] In some implementations, in the plane perpendicular to the thickness direction of the first wall 215, the extension portion 920 is arranged around the outer periphery of the second accommodating cavity 60.

[0239] ​It should be understood that, in a plane perpendicular to the thickness direction of the first wall 215, the extension 920 can be continuously arranged around the outer periphery of the second accommodating cavity 60, that is, the extension 920 can be a closed whole structure, or the extension 920 can include a plurality of sub-extensions (not shown in the figure) which are arranged at intervals around the outer periphery of the second accommodating cavity 60. It should also be understood that, in the case where the plurality of sub-extensions are arranged at intervals around the outer periphery of the second accommodating cavity 60, the distance between any two adjacent sub-extensions can be set according to actual needs, for example, the distance between the geometric centers of any two adjacent sub-extensions in a plane perpendicular to the thickness direction of the first wall 215 can be equal.

[0240] In the embodiment of the present application, by arranging the extension 920 around the outer periphery of the second accommodating cavity 60 in a plane perpendicular to the thickness direction of the first wall 215, the risk of electrolyte splashing into the second accommodating cavity 60 during the injection of electrolyte into the battery monomer 20 can be further reduced, thereby improving the use performance of the battery monomer 20.

[0241] In some implementations, as shown in Figure 13 The extension 920 is a ring structure, and the inner ring of the ring structure surrounds the outer periphery of the second accommodating cavity 60.

[0242] It should be understood that, in the embodiment of the present application, in a plane perpendicular to the thickness direction of the first wall 215, the extension 920 can be a closed ring structure such as a circular ring, a polygonal ring, a waist-shaped ring, a special-shaped ring, etc. It should also be understood that the extension 920 can also be a non-closed ring structure, for example, the extension 920 is a circular ring with a notch, which is not limited in the embodiment of the present application as an example.

[0243] In the embodiment of the present application, by arranging the extension 920 as a ring structure and the inner ring of the ring structure around the outer periphery of the second accommodating cavity 60, the risk of electrolyte splashing into the second accommodating cavity 60 during the injection of electrolyte into the battery monomer 20 can be further reduced, thereby improving the use performance of the battery monomer 20, and the structure of the extension 920 is simple, facilitating processing and manufacturing.

[0244] In some implementations, as shown in Figure 3As shown, along the direction of gravity, the first wall 215 is a bottom wall of the shell 21. In this way, in the embodiments of the present application, along the direction of gravity, by setting the first wall 215 as the bottom wall of the shell 21, in the case that the pressure or temperature inside the battery monomer 20 reaches a threshold value, the deformation and cracking of the pressure relief portion 213 on the first wall 215 are facilitated, so that the pressure relief portion 213 can be actuated in time to discharge the high-temperature discharge inside the battery monomer 20 to the outside of the battery monomer 20, thereby improving the use performance of the battery monomer 20, and facilitating the processing and manufacturing of the battery monomer 20.

[0245] According to some embodiments of the present application, the embodiments of the present application further provide a battery device 10 comprising a plurality of battery monomers 20, the battery monomer 20 being the battery monomer 20 in any of the above embodiments.

[0246] According to some embodiments of the present application, the embodiments of the present application further provide a battery device 10 comprising a plurality of battery monomers 20, the battery monomer 20 being the battery monomer 20 in any of the above embodiments. Figure 1 The vehicle 1 as shown can also be any electric device using the battery device 10.

[0247] The electric device can be any of the above-mentioned application devices or systems using the battery device 10.

[0248] According to some embodiments of the present application, the embodiments of the present application further provide an energy storage device comprising the battery device 10 in any of the above embodiments, the battery device 10 being used to store electrical energy for the energy storage device.

[0249] According to some embodiments of the present application, referring to Figure 5 to Figure 8The application provides a battery monomer 20, which comprises an electrode assembly 22 and a shell 21, the shell 21 comprises a first accommodating cavity 50 and a first wall 215, the electrode assembly 22 is accommodated in the first accommodating cavity 50, the first wall 215 comprises a body part 230, a first protruding part 2153 and a pressure relief part 213, the first protruding part 2153 protrudes from the body part 230 in the direction of the electrode assembly 22, and the first protruding part 2153 connects the body part 230 and the pressure relief part 213, the pressure relief part 213 is arranged on the side of the first protruding part 2153 close to the electrode assembly 22, the body part 230, the first protruding part 2153 and the pressure relief part 213 enclose a second accommodating cavity 60 with an opening away from the electrode assembly 22; wherein the inner wall 70 of the second accommodating cavity 60 is provided with an inner recess 80. The inner wall 70 of the second accommodating cavity 60 comprises a planar area 710 and a circular arc area 720, the inner recess 80 comprises a first inner recess 810, and the first inner recess 810 is arranged on the circular arc area 720. The circular arc area 720 comprises a first circular arc area 721 and a second circular arc area 722 opposite in a first direction, the first inner recess 810 comprises a first sub-inner recess 811 and a second sub-inner recess 812, the first sub-inner recess 811 is arranged on the first circular arc area 721, and the second sub-inner recess 812 is arranged on the second circular arc area 722, the first direction is the extension direction of the planar area 710, and a second direction is perpendicular to the first direction. The first sub-inner recess 811 and the second sub-inner recess 812 are respectively arranged symmetrically in the second direction.

[0250] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application, and they should be covered in the scope of the claims and the description of the application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: Electrode assembly (22); The outer casing (21) includes a first receiving cavity (50) and a first wall (215). The electrode assembly (22) is received in the first receiving cavity (50). The first wall (215) includes a body portion (230), a first protrusion (2153), and a pressure relief portion (213). The first protrusion (2153) protrudes from the body portion (230) toward the electrode assembly (22) and connects the body portion (230) and the pressure relief portion (213). The pressure relief portion (213) is disposed on the side of the first protrusion (2153) near the electrode assembly (22). The body portion (230), the first protrusion (2153), and the pressure relief portion (213) enclose to form a second receiving cavity (60) with an opening away from the electrode assembly (22). The inner wall (70) of the second receiving cavity (60) is provided with a recess (80).

2. The battery cell according to claim 1, characterized in that, The inner wall (70) of the second receiving cavity (60) includes a planar region (710) and an arcuate region (720), and the concave portion (80) includes a first concave portion (810), which is disposed in the arcuate region (720).

3. The battery cell according to claim 2, characterized in that, The arc region (720) includes a first arc region (721) and a second arc region (722) that are opposite each other along a first direction. The first concave portion (810) includes a first sub-concave portion (811) and a second sub-concave portion (812). The first sub-concave portion (811) is disposed in the first arc region (721), and the second sub-concave portion (812) is disposed in the second arc region (722). The first direction is the extension direction of the planar region (710).

4. The battery cell according to claim 3, characterized in that, The first sub-concave portion (811) and the second sub-concave portion (812) are respectively symmetrically arranged along a second direction, which is perpendicular to the first direction.

5. The battery cell according to claim 2, characterized in that, The recessed portion (80) further includes a second recessed portion (820), which is disposed in the planar region (710) and close to the arc region (720).

6. The battery cell according to claim 5, characterized in that, The recess (80) further includes a third recess (830), which is provided on the surface of the second receiving cavity (60) away from the electrode assembly (22).

7. The battery cell according to claim 6, characterized in that, The battery cell is a square battery cell. On a plane perpendicular to the thickness direction of the first wall (215), the second receiving cavity (60) includes a planar segment (610) and an arc segment (620). The first wall (215) includes a first side (217) and a second side (218) that are perpendicular to each other. Wherein, the ratio between the dimension D3 of the first side (217) and the dimension D4 of the second side (218) satisfies the condition that when D3 / D4≥5, the plane segment (610) is parallel to the first side (217).

8. The battery cell according to claim 7, characterized in that, The first wall (215) is provided with an injection hole (216) that penetrates the first wall (215) along the thickness direction of the first wall (215). The arc region (720) includes a first sub-arc region (730) that is away from the injection hole (216). The third concave portion (830) is provided in the planar region (710) and close to the first sub-arc region (730).

9. The battery cell according to claim 6, characterized in that, The battery cell is a square battery cell. On a plane perpendicular to the thickness direction of the first wall (215), the second receiving cavity (60) includes a planar segment (610) and an arc segment (620). The first wall (215) includes a first side (217) and a second side (218) that are perpendicular to each other. Wherein, the ratio between the dimension D3 of the first side (217) and the dimension D4 of the second side (218) satisfies the condition that D3 / D4≤3, the plane segment (610) is parallel to the second side (218).

10. The battery cell according to claim 9, characterized in that, The first wall (215) is provided with an injection hole (216) that penetrates the first wall (215) along the thickness direction of the first wall (215). The inner wall (70) of the second receiving cavity (60) includes a planar region (710) and an arc region (720). The planar region (710) includes a first sub-planar region (750) away from the injection hole (216). The third recess (830) is disposed in the first sub-planar region (750).

11. The battery cell according to claim 6, characterized in that, The planar region (710) includes a first planar region (711) and a second planar region (712) that are opposite each other along a second direction. The third recess (830) includes a third sub-recess (831) and a fourth sub-recess (832). The third sub-recess (831) is disposed in the first planar region (711), and the fourth sub-recess (832) is disposed in the second planar region (712). The second direction is perpendicular to the extension direction of the planar region (710).

12. The battery cell according to claim 11, characterized in that, The third sub-concave portion (831) and the fourth sub-concave portion (832) are respectively symmetrically arranged along a first direction, which is perpendicular to the second direction.

13. The battery cell according to claim 7, characterized in that, The minimum dimensions of the first recess (810), the second recess (820), and the third recess (830) along the thickness direction of the first wall (215) are all greater than or equal to 0.2 mm and less than or equal to 1 mm.

14. The battery cell according to claim 1, characterized in that, The battery cell also includes a protective member (90), which is fixedly connected to the surface of the second receiving cavity (60) away from the electrode assembly (22). On a plane perpendicular to the thickness direction of the first wall (215), the orthographic projection of the protective member (90) covers the orthographic projection of the second receiving cavity (60).

15. The battery cell according to claim 14, characterized in that, The first wall (215) further includes a second protrusion (2154) that protrudes from the body portion (230) in a direction away from the electrode assembly (22). The second protrusion (2154) includes a first groove (930) that opens away from the second receiving cavity (60). At least a portion of the protective member (90) is received in the first groove (930). On a plane perpendicular to the thickness direction of the first wall (215), the orthographic projection of the protective member (90) covers the orthographic projection of the second receiving cavity (60).

16. The battery cell according to claim 14, characterized in that, The protective component (90) includes a main body (910) and an extension (920) connected to each other. The first wall (215) is also provided with an injection hole (216) that penetrates the first wall (215) along the thickness direction of the first wall (215). The extension (920) is located between the injection hole (216) and the second receiving cavity (60) and is disposed close to the injection hole (216).

17. The battery cell according to claim 16, characterized in that, On a plane perpendicular to the thickness direction of the first wall (215), the extension (920) is disposed around the outer periphery of the second receiving cavity (60).

18. The battery cell according to claim 17, characterized in that, The extension (920) is a ring structure, and the inner ring of the ring structure surrounds the outer periphery of the second receiving cavity (60).

19. The battery cell according to any one of claims 1 to 18, characterized in that, Along the direction of gravity, the first wall (215) is the bottom wall of the outer shell (21).

20. A battery device, characterized in that, include: Multiple battery cells, wherein the battery cells are as described in any one of claims 1 to 19.

21. An electrical appliance, characterized in that, include: The battery device of claim 20, wherein the battery device is used to provide electrical energy to the electrical device.

22. An energy storage device, characterized in that, include: The battery device of claim 20, wherein the battery device is used to store electrical energy for the energy storage device.

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