CN112838303B

CN112838303B - Battery, battery module, battery pack and electric vehicle

Info

Publication number: CN112838303B
Application number: CN201911163515.2A
Authority: CN
Inventors: 潘仪; 吴煊伟; 朱燕; 王信月
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2022-01-07
Anticipated expiration: 2039-11-22
Also published as: CN112838303A

Abstract

The application provides a battery, a battery module, a battery pack and an electric vehicle. The battery includes at least two casings, a plurality of cover plates, and at least two pole core groups. The at least two housings are arranged in sequence along a first direction of the cell. And the two opposite ends of each shell are respectively connected with the cover plate in a sealing manner to form an accommodating cavity. Every it is provided with to hold the intracavity utmost point core group, utmost point core group contains at least one utmost point core, at least two utmost point core group series connection. Two adjacent shells are fixedly connected at the joint through the same cover plate and are sealed and isolated from the containing cavities. The battery that this application provided realizes the series connection of a plurality of utmost point core groups through simpler mounting structure to have higher battery capacity and voltage, and less internal consumption, be favorable to improving the whole capacity and the voltage of battery package, thereby promote the duration of electric motor car.

Description

Battery, battery module, battery pack and electric vehicle

Technical Field

The application belongs to the battery field, especially relates to a battery, battery module, battery package and electric motor car.

Background

With the continuous popularization of new energy automobiles, the use requirement of power batteries in the new energy automobiles becomes higher and higher. Particularly, the continuous mileage requirement of a user on a new energy automobile is continuously improved, and the total capacity of a power battery pack used by the new energy automobile needs to be continuously improved; meanwhile, in the using process of the power battery pack, the internal consumption caused by the internal resistance is required to be reduced as much as possible.

Generally speaking, only be equipped with a naked electric core or a plurality of naked electric core that are in the parallel state in the shell of battery, and contain single naked electric core or a plurality of parallelly connected electric core and can't improve the voltage of whole battery. For example, the voltage of a lithium titanate-based battery is 2.4 volts, the voltage of a lithium iron phosphate-based battery is 3.2 volts, the voltage of a ternary-based battery is 3.7 volts, and the voltage of a multipolymer-based battery is 4.3 volts. Therefore, when a high voltage (high capacity) is required, a plurality of batteries are connected in series to form a battery pack, and the battery pack is assembled to a power battery pack.

The width of a common new energy automobile is generally more than 1 meter, and the length of the common new energy automobile is several meters. The power battery pack serving as the new energy automobile is generally placed at the bottom of the new energy automobile. At present, the width of a power battery pack on the market is generally approximately consistent with that of a new energy automobile, and is approximately more than 1 meter. The length is determined according to the reserved space at the bottom of the new energy automobile and is generally more than 2 meters. In the whole, the size of the power battery pack exceeds 1 meter in both the length direction and the width direction, and the length of the batteries in the market is about 0.3 meter at present, so at least 3 batteries or even more batteries need to be connected in series in each battery pack, and the adjacent two batteries need to be connected with each other through a peripheral power connecting piece in a power connection manner, so that the number of battery mounting structures is large, the cost is increased, and the whole weight of the power battery pack is increased; meanwhile, the mounting structure occupies the inner space of the bag body with more battery bags, so that the overall capacity of the power battery bag is reduced, the more the number of batteries is, and the more the space is wasted. In addition, because of need set up a plurality of external power connecting pieces and carry out the power connection, lead to the internal resistance to increase, improved the internal consumption of power battery package in use.

Disclosure of Invention

The present disclosure is directed to solving at least one of the problems in the prior art. To this end, in a first aspect of the present application, there is provided a battery including at least two cases, a plurality of cap plates, and at least two pole core groups. Wherein the at least two housings are arranged in sequence along a first direction of the cell. And the two opposite ends of each shell are respectively connected with the cover plate in a sealing manner to form an accommodating cavity. Every it is provided with to hold the intracavity utmost point core group, utmost point core group contains at least one utmost point core, at least two utmost point core group series connection. Two adjacent shells are fixedly connected at the joint through the same cover plate and are sealed and isolated from the containing cavities.

In a second aspect of the present application, a battery module is provided, which includes the battery as described above.

In a third aspect of the present application, a battery pack is provided, which includes the above-mentioned battery or battery module.

In a fourth aspect of the present application, there is provided an electric vehicle including the above-described battery pack, battery module, or battery.

Compared with the prior art, the beneficial effect that this application has does: the battery comprises a cover plate, at least two shells, a plurality of pole core groups and a plurality of pole core groups, wherein the two opposite ends of each shell are respectively connected with the cover plate in a sealing manner to form accommodating cavities; in addition, the same cover plate is shared at the joint between two adjacent shells for sealing connection, so that the mounting structure of the battery can be simplified, the space between two adjacent pole core groups is reduced, the space utilization rate of the battery pack is improved, the internal consumption of the power battery pack is reduced, the overall capacity and voltage of the battery pack are improved, and the cruising ability of the electric vehicle is improved.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

Fig. 1 is a schematic view of an overall structure of a battery according to an embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of the battery shown in fig. 1 taken along the direction a-a.

Fig. 3 is a partially enlarged view of fig. 2 at B.

Fig. 4 is an exploded view of a battery according to another embodiment of the present disclosure.

Fig. 5 is a partial enlarged view of fig. 4 at E.

Fig. 6 is a schematic structural view of a second cover plate and a pole piece integrally injection-molded according to another embodiment of the present application.

Fig. 7 is a partially enlarged view at C in fig. 2.

Fig. 8 is an exploded view of a battery according to another embodiment of the present disclosure.

Fig. 9 is a schematic structural view of a liquid injection channel provided on a second cover plate according to another embodiment of the present application.

Fig. 10 is a schematic structural view of a second cover plate provided with a liquid injection channel according to another embodiment of the present application.

Fig. 11 is a schematic structural view of a second cover plate provided with a liquid guiding through hole according to another embodiment of the present application.

FIG. 12 is a schematic view of a seal member in sealing engagement with a seal channel according to an embodiment of the present application.

Fig. 13 is a cross-sectional view of the structure shown in fig. 12.

FIG. 14 is a schematic view of a seal member in sealing engagement with a seal channel according to another embodiment of the present application.

Fig. 15 is a front view of the structure shown in fig. 14.

Fig. 16 is a cross-sectional view of the structure shown in fig. 14.

FIG. 17 is a schematic view of a seal member in sealing engagement with a seal channel according to another embodiment of the present application.

Fig. 18 is a front view of the structure shown in fig. 17.

Fig. 19 is a cross-sectional view of the structure shown in fig. 17.

FIG. 20 is a schematic view of a seal member in sealing engagement with a seal channel according to another embodiment of the present application.

Fig. 21 is a front view of the structure shown in fig. 20.

Fig. 22 is a cross-sectional view of the structure shown in fig. 20.

FIG. 23 is a schematic view of a seal member in sealing engagement with a seal channel according to another embodiment of the present application.

Fig. 24 is a schematic structural diagram of a battery pack provided in an embodiment of the present application.

Description of the main elements

Battery 100

Housing 11

Abutting part 111

Isolation diaphragm 112

Cover plate 12

First cover plate 121

Second cover plate 122

Connecting via 123

Package structure 124

Side 125

Circumferential surface 126

First circumferential surface 1261

Second circumferential surface 1262

Pole core group 13

First electrode lead-out member 131

Second electrode lead-out member 132

Accommodating chamber 14

Sealed chambers

141, 142

Pole core connection piece 15

Copper connection 151

Aluminum connecting part 152

Liquid injection channel 16

Liquid inlet 161

Liquid outlet 162

First passage 163

Second passage 164

Third channel 165

Fourth channel 166

Plugging piece 17

Liquid guiding through hole 18

Seal 19

Sealing ring 191

Metal ball 192

Sealing boot 193

Sealing the channel 20

Outer cover 50

Tray 51

Cover 52

The following detailed description will further illustrate the present application in conjunction with the above-described figures.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the present application.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

As shown in fig. 1 and 2, the present application provides a battery 100 including at least two cases 11, a plurality of cap plates 12, and at least two pole core groups 13. The at least two shells 11 are sequentially arranged along a first direction of the battery 100, and two opposite ends of each shell 11 are respectively connected with the cover plate 12 in a sealing manner to form an accommodating cavity 14, so that the battery comprises at least two accommodating cavities 14. For example, the first direction is the X direction shown in fig. 1.

The battery 100 may be a lithium ion battery, and the first direction is a length direction of the battery 100. In this application, casing 11 is used for improving battery 100's intensity, guarantees battery 100's safe handling, can be plastic housing, also can be metal casing, and when being metal casing, heat dispersion is better, and the intensity of casing is higher, can self play the effect of support.

In the present embodiment, two adjacent housings 11 are fixedly connected at the joint by the same cover plate 12 and are sealed from the respective accommodating cavities 14. The fixing connection between the housing and the cover plate is not particularly limited, and for example, the housing and the cover plate are sealed by gluing. Or when the shell and the cover plate are both metal pieces, the shell and the cover plate can be hermetically connected in a welding mode.

Specifically, the plurality of cover plates 12 includes two first cover plates 121 and at least one second cover plate 122. One of the first cap plates 121 is disposed at one end of the battery 100 in the first direction, and the other of the first cap plates 121 is disposed at the other end of the battery 100 in the first direction. The second cover plate 122 is disposed between the two first cover plates 121, and two adjacent housings 11 are hermetically connected to the same second cover plate 122 at a junction.

One of the opposite ends of the housing 11 is hermetically connected to the first cover plate 121 or the second cover plate 122, and the other end is hermetically connected to the second cover plate 122. For example, when the number of the cases 11 is three or more, one end of the case 11 located at the end of the battery 100 in the first direction is hermetically connected to the first cover plate 121, and the other end is hermetically connected to the second cover plate 122. Both opposite ends of the case 11 between the ends of the battery 100 in the first direction are hermetically connected to the second cover 122.

In this embodiment, the pole core group 13 is disposed in each accommodating cavity 14, the pole core group 13 includes at least one pole core, and the at least two pole core groups 13 are connected in series.

In one embodiment, as shown in fig. 2, one pole core group 13 is arranged in each accommodating cavity 14, and the pole core groups 13 in two adjacent accommodating cavities 14 are connected in series. Thus, the at least two pole core groups 13 are sequentially connected in series. In other embodiments, a plurality of pole core groups 13, for example, 2 or more than 2, may be arranged in the accommodating cavity 14 side by side. In the present application, it is desirable to arrange a pole core assembly 13 in a receiving cavity 14 to achieve the best isolation effect.

The pole core mentioned in the present application is a pole core commonly used in the field of power batteries, and the pole core group 13 are components inside the housing 11 of the battery 100, and cannot be understood as the battery 100 itself. The pole core can be formed by winding or can be manufactured in a lamination mode. Generally, the core includes at least a positive electrode sheet, a separator, and a negative electrode sheet, and an electrolyte, and generally refers to an assembly that is not completely sealed. Thus, the battery 100 referred to herein is a single battery, and cannot be simply understood as a battery module or a battery pack because it includes a plurality of pole pieces. In the present application, the pole core group 13 may be composed of a single pole core, or may include at least two pole cores, and at least two pole cores are connected in parallel to constitute the pole core group 13.

In the present application, by connecting the at least two pole core groups 13 in series, it is possible to achieve high capacity and high voltage of the battery 100 and to reduce the manufacturing process and cost.

In general, the number of the series-connected electrode core groups included in the battery 100 may be determined according to the output voltage of each electrode core group 13, the width of the applied battery pack, and the overall voltage requirement of the battery pack. For example, a vehicle type needs the voltage output by a battery system to be 300V, the voltage of a traditional lithium iron battery is 3.2V, and in the prior art, 100 batteries need to be connected in series in a bag body to meet the requirement. In the battery pack provided by the present application, assuming that 2 pole core groups 13 are connected in series in one battery, only 50 batteries 100 need to be arranged; by analogy, if 10 pole core groups 13 are connected in series, only 10 batteries 100 need to be connected in series. Therefore, the design of the whole pack and the arrangement of the batteries can be greatly reduced, the space can be effectively utilized, and the space utilization rate is improved.

In the prior art, in order to realize high capacity and high voltage of the battery, two or more batteries are generally required to be connected in series. However, the connection between two adjacent batteries connected in series needs to be connected with the external power connecting piece through the cover plates at the respective ends, so that the number of battery mounting structures is large, the cost is increased, and the overall weight of the power battery pack is increased; meanwhile, the mounting structure occupies more inner space of the bag body of the battery bag, so that the overall capacity of the power battery bag is reduced. In addition, because of need set up a plurality of external power connecting pieces and carry out the power connection, lead to the internal resistance to increase, improved the internal consumption of power battery package in use.

Compared with the prior art, the battery 100 has the advantages that the at least two shells 11 are arranged, the two opposite ends of each shell 11 are respectively connected with the cover plate 12 in a sealing mode to form the containing cavities 14, the pole core groups 13 are arranged in the containing cavities 14, and the pole core groups 13 in the containing cavities 14 are connected in series, so that the capacity and the voltage of the battery 100 can be effectively improved; in addition, the same cover plate 12 is shared at the joint between two adjacent shells 11 for sealing connection, so that the mounting structure of the battery 100 can be simplified, the space between two adjacent pole core groups 13 is reduced, the space utilization rate of the battery pack is improved, the internal consumption of the power battery pack is reduced, the battery pack has more internal spaces for accommodating the battery, the overall capacity and voltage of the battery pack are further improved, and the cruising ability of the electric vehicle using the battery pack is improved.

In the present embodiment, the longitudinal directions of the housing 11 and the pole core group 13 extend in the first direction.

In the present application, as shown in fig. 1, the battery 100 is substantially a rectangular parallelepiped, the battery 100 has a length L, a width H, and a thickness D, the length L of the battery 100 is greater than the width H, and the width H of the battery 100 is greater than the thickness D. Wherein, the length of the battery 100 can be 400-2500 mm. In the present application, the ratio of the length L to the width H of the battery 100 is 4 to 21.

It should be noted that the battery 100 is substantially rectangular parallelepiped, and it is understood that the battery 100 may have a rectangular parallelepiped shape, a square shape, or a shape having a shape partially but substantially rectangular parallelepiped shape or square shape, or a shape having a notch, a protrusion, a chamfer, a curvature, or a curvature partially but substantially rectangular parallelepiped shape or square shape as a whole.

In the prior art, in order to improve the volume utilization rate of a battery pack, the size of the battery is set to be 400-2500 mm, and due to the fact that the battery is too long, if only one pole core is arranged, the internal resistance of the battery is too high, the potential difference between the two ends of the positive pole and the negative pole is too large, and the electrolyte cannot work normally. And adopt the technical scheme of this application can be comparatively convenient produce the battery 100 of length at 400 ~ 2500mm, can reduce the connection of internal resistance and structure again simultaneously, and the cost can further reduce.

In the present application, as shown in fig. 3, each of the electrode core groups 13 includes a first electrode drawing part 131 and a second electrode drawing part 132 for drawing an electric current. In this embodiment, the first electrode drawing member 131 and the second electrode drawing member 132 are respectively disposed on opposite sides of the electrode core group 13 along the first direction.

This application is through following all casing 11 and all utmost point core groups 13 the first direction is arranged to draw forth part 131 and second electrode lead-out part 132 with the first electrode of utmost point core group 13 and locate the relative both sides of this utmost point core group 13 along the first direction branch, adopt the mode of arranging of "head to head" between each utmost point core group 13 promptly, this mode of arranging can realize comparatively conveniently establish ties between two adjacent utmost point core groups 13 in battery 100, connection structure is simple. In addition, the battery with longer length can be manufactured conveniently by adopting the arrangement mode.

Generally, each of the pole core groups 13 includes a first electrode drawing part 131 and a second electrode drawing part 132 for drawing current, and if the pole core group 13 includes only one pole core, the first electrode drawing part 131 and the second electrode drawing part 132 may be a positive tab and a negative tab of the pole core, respectively, or a negative tab and a positive tab, respectively. If the pole core group 13 comprises a plurality of pole cores, the first electrode lead-out part can be a lead-out part formed by compounding and welding positive pole ears together, and the second electrode lead-out part can be a lead-out part formed by compounding and welding negative pole ears together; alternatively, the first electrode lead-out member may be a lead-out member formed by compounding and welding together negative electrode tabs, and the second electrode lead-out member may be a lead-out member formed by compounding and welding together positive electrode tabs. The "first" and "second" of the first electrode drawing member 131 and the second electrode drawing member 132 are used for name distinction only and are not limited to a number, and for example, the first electrode drawing member may include one or a plurality of members.

The serial connection mode provided by this embodiment may be serial connection between adjacent pole core groups 13, and the specific implementation mode may be direct connection of the current leading-out components on the adjacent pole core groups 13, or may be electrical connection implemented through an additional conductive component, that is, direct electrical connection or indirect connection may be implemented between the pole core groups 13 in the two adjacent accommodating cavities 14.

Specifically, in one embodiment, as shown in fig. 3, the battery 100 further includes a pole piece connector 15, and the pole piece connector 15 penetrates through the second cover plate 122. For example, the second cover plate 122 is provided with a connecting through hole 123, and the pole piece connecting member 15 is inserted into the connecting through hole 123, that is, the pole piece connecting member 15 is inserted from one side of the connecting through hole 123 to the other side.

In the one embodiment, the first electrode drawing part 131 of one of the pole core groups 13 in the two adjacent accommodating cavities 14 is electrically connected with the second electrode drawing part 132 of the other pole core group 13 through the pole core connecting member 15, that is, the pole core groups 13 in the two adjacent accommodating cavities 14 are indirectly connected.

In the embodiment, two adjacent pole core groups 13 are connected through the pole core connecting piece 15, so that a larger design space can be provided for the pole core connecting piece 15, the flow area is increased, and the internal resistance of the battery 100 is reduced.

In some embodiments, the pole piece connection 15 may be a sheet structure. Alternatively, in some embodiments, as shown in fig. 4, the pole piece connection member 15 may be a columnar structure.

The first electrode lead-out member 131 and the second electrode lead-out member 132 may be directly welded to the corresponding pole core connecting member 15 in the second cover plate 122. Compared with the existing batteries which are connected in series, the welding procedures and steps are reduced, the risk possibly brought by poor welding is reduced, and the overall safety and reliability of the batteries are improved.

As shown in fig. 3, the pole piece connection member 15 includes a copper connection portion 151 and an aluminum connection portion 152 electrically connected to each other. Since copper and aluminum have a potential difference with respect to lithium, corrosion is likely to occur when a contact portion between the copper connection portion 151 and the aluminum connection portion 152 is in contact with the electrolyte. In the one embodiment, the copper connection part 151 and the aluminum connection part 152 are electrically connected to each other inside the second cap plate 122.

In order to avoid corrosion of the place where the copper connecting portion 151 and the aluminum connecting portion 152 are electrically connected by the electrolyte and to isolate the receiving cavities 14 on both sides of the second cover plate 122 and prevent the electrolyte in the receiving cavities 14 on both sides of the second cover plate 122 from penetrating into each other, in some embodiments, as shown in fig. 3, the battery 100 further includes a packaging structure 124 disposed in the connecting through hole 123, wherein the packaging structure 124 is used for packaging the pole core connecting member 15 in the connecting through hole 123, and the packaging structure 124 can seal the connecting through hole 123. In this way, the contact position between the copper connection portion 151 and the aluminum connection portion 152 is sealed inside the second cap plate 122, so as to prevent the contact position from being exposed to the internal space of the battery, especially, the contact position from the electrolyte, and prevent the corrosion of the copper-aluminum connection position.

In the present application, the package structure 124 may be a rubber plug, for example, as long as it can perform sealing performance, resist electrolyte corrosion, and be insulated.

In the installation scheme of the pole core connecting piece 15 provided by the above embodiment, the connecting through hole 123 needs to be packaged for the second time, which is very inconvenient to operate. Meanwhile, when performing secondary packaging, the material selection of the packaging structure 124 is complex, and may affect the electrolyte inside the battery. In view of this, in another embodiment, as shown in fig. 6, a solution is provided in which the pole piece connection 15 is integrally injection molded with the second cover plate 122. In this embodiment, the pole piece connecting member 15 and the second cover plate 122 are integrally formed by injection molding. Specifically, the pole piece connecting member 15 is manufactured first, and then the second cover plate 122 is injection molded outside the pole piece connecting member 15. In order to better achieve the sealing effect of the second cover plate 122, in the integral injection molding process, the part where the plastic contacts the metal is formed by an EPI molding technique, for example, a nano plastic layer is sintered on the surface of the metal, such as PPE, PPS, etc., and then an integral injection molding of a plastic part is performed. By adopting the method, the metal layer and the plastic layer can be combined together more effectively, and the sealing performance of the whole structural member is improved. In the assembling process, the pole core group 13 is directly connected with the pole core connecting piece 15, no through hole needs to be packaged, the process is simplified, and meanwhile, the risk is reduced.

In still another embodiment, the first electrode drawing part 131 of one of the pole core groups 13 of the adjacent two pole core groups 13 in the receiving cavities 14 may be electrically connected with the second electrode drawing part 132 of the other pole core group 13, and the connection of the first electrode drawing part 131 and the second electrode drawing part is located in the second cover plate 122 between the two pole core groups 13. That is, the first electrode lead-out member 131 is directly electrically connected to the second electrode lead-out member 132. Here, the connection point of the first electrode drawing member 131 and the second electrode drawing member 132 refers to a position where the first electrode drawing member 131 and the second electrode drawing member 132 are connected to each other.

Similar to the previous embodiment, in order to facilitate the electrical connection between the first electrode drawing member 131 and the second electrode drawing member 132, a connecting through hole is formed on the second cover plate 122, and the connection point of the first electrode drawing member 131 and the second electrode drawing member 132 is located in the connecting through hole of the second cover plate 122 between the two pole core groups 13.

In order to prevent the electrolyte in the accommodating cavities 14 of the pole core groups 13 on both sides of the second cover plate 122 from mutually permeating, the battery 100 further includes an encapsulating structure disposed in the connecting through hole, the encapsulating structure is used for encapsulating the joint in the connecting through hole, and the encapsulating structure closes the connecting through hole, so that the first electrode leading-out part and the second electrode leading-out part are hermetically connected with the second cover plate 122, and the electrolyte in two adjacent pole core groups 13 on both sides of the second cover plate 122 is isolated from mutually moving.

In the embodiment, as the same cover plate 12 is shared between two adjacent shells 11, the distance between two electrode core groups 13 is greatly reduced, and compared with the prior art in which two batteries are connected with an external power connector through the first electrode lead-out part 131 and the second electrode lead-out part 132, the assembly process of a subsequent battery pack is simplified; meanwhile, the use of materials is reduced, and the weight is reduced.

Referring to fig. 3 again, the cover plate 12 (including the first cover plate 121 and the second cover plate 122) includes a side surface 125 facing the adjacent pole core group 13 and a circumferential surface 126 connected to the side surface 125. In order to maintain the flatness and aesthetic effect of the outer surface of the battery 100, the circumferential surface 126 of the cap plate 12 is flush with the outer surface of the case 11.

In order to improve the reliability of the connection of the cover plate 12 to the corresponding housing 11, in one embodiment, the circumferential surface 126 includes a first circumferential surface 1261 and a second circumferential surface 1262 protruding from the first circumferential surface 1261, i.e., the circumferential surface 126 has a step-like structure. Accordingly, the end of the housing 11 may extend outward to form a supporting portion 111, and the supporting portion 111 is abutted on the first circumferential surface 1261 of the cover plate 12 fixedly connected thereto. Wherein the second circumferential surface 1262 is flush with the outer surface of the housing 11.

It is to be appreciated that, since both sides of the second cover plate 122 are connected to the housing 11, as shown in fig. 3 and 5, the second cover plate 122 may include two first circumferential surfaces 1261 and one second circumferential surface 1262 between the two first circumferential surfaces 1261. Since only one side of the first cover plate 121 is connected to the housing 11, as shown in fig. 7, the first cover plate 121 may include only one first circumferential surface 1261 and one second circumferential surface 1262.

Referring to fig. 2 and 3 again, each of the accommodating cavities 14 is connected to the corresponding cover plate 12 through the corresponding housing 11, so as to form a sealed chamber 141 for accommodating and sealing the corresponding pole core assembly 13. As such, the cavity wall of each sealed chamber 141 includes a corresponding housing 11, and cover plates 12 sealingly connected to opposite ends of the corresponding housing 11.

Specifically, the cavity wall of the sealed chamber 141 at the end of the battery 100 in the first direction includes the corresponding housing 11, the first cover plate 121 hermetically connected to one end of the corresponding housing 11, and the second cover plate 122 hermetically connected to the other end of the corresponding housing 11. The cavity wall of the sealed chamber 141 between the ends of the battery 100 along the first direction includes a corresponding housing 11, and a second cover plate 122 hermetically connected to both ends of the corresponding housing 11.

Wherein, the housing 11 may be a metal housing with an insulated inner surface.

In the present application, when a plurality of pole core groups 13 are connected in series, the electrolytes in different pole core groups 13 may have an internal short circuit problem under the condition of communication, and a higher potential difference exists between different pole core groups 13 (taking a lithium iron phosphate battery as an example, the potential difference is about 4.0-7.6V), and the electrolytes in the different pole core groups may be decomposed due to the larger potential difference, which affects the battery performance. In order to better perform the function of insulation, the cover plate 12 itself may be made of an insulating material, i.e. the cover plate 12 is an insulating cover plate. In this way, it is possible to isolate the adjacent two pole core groups 13 directly by the second cover plate 122 and maintain the insulation therebetween without performing other operations.

In another embodiment, as shown in fig. 8, the housing 11 further includes a separation film 112 disposed in the accommodating cavity 14, opposite ends of the separation film 112 are sealingly connected to the cover plates 12 at two ends of the accommodating cavity 14, so as to form a sealed chamber 142 in the accommodating cavity 14, and the pole core group 13 is disposed in the corresponding sealed chamber 142 in the accommodating cavity 14. Wherein the wall of each sealed chamber 142 includes a corresponding isolation diaphragm 112, and a cover plate 12 sealingly connected to opposite ends of the corresponding isolation diaphragm 112.

In the another embodiment, the isolation film 112 is a cylindrical structure with two open ends, the pole core group 13 is located inside the cylindrical isolation film 112, and the cover plate 12 is sealed with the two open ends of the isolation film 112. The sealing manner and the specific structure of the isolation film 112 and the cover plate 12 are not particularly limited, for example, when the cover plate 12 is a plastic cover plate and the isolation film 112 is made of plastic, hot-melt sealing can be used between the two.

In this application, establish ties between a plurality of utmost point core group 13, because the voltage is different between different utmost point core group 13, can lead to casing 11, like the aluminum hull, local potential is low excessively, very easily leads to inside lithium ion embedding shell this moment, forms lithium aluminum alloy, corrodes the aluminum hull. The other embodiment can effectively isolate the contact of the electrolyte with the case 11 by providing the separation film 112 between the case 11 and the pole core group 13.

The separator 112 has a certain insulation property and an electrolyte corrosion resistance, and the material of the separator 112 is not particularly limited as long as it can insulate and does not react with the electrolyte. In some embodiments, the material of the release film 112 may include polypropylene (PP), Polyethylene (PE), or a multi-layer composite film, for example, in some embodiments, a multi-layer composite film including an inner layer, an outer layer, and an intermediate layer between the inner and outer layers. Wherein the inner layer comprises a plastic material, for example the inner layer may be made using a material that is less reactive with the electrolyte within the separator 112 and has insulating properties, for example PP or PE. The intermediate layer includes a metal material so that it is possible to prevent moisture permeation outside the battery 100 while preventing permeation of the internal electrolyte. As the metal layer, aluminum foil, stainless steel foil, copper foil, or the like is preferably used. The outer layer is a protective layer, and is made of a high-melting-point stop or nylon material, so that the battery 100 has strong mechanical performance, is prevented from being damaged by external force, and plays a role in protecting the battery 100. In some embodiments, the separator 112 also has flexibility to facilitate the molding process of the battery 100 and to prevent puncture and the like.

In order to inject the electrolyte into the sealed chamber where the pole core assembly 13 is located, taking fig. 3 as an example, the second cover plate 122 is further provided with a liquid injection channel 16 for communicating the sealed chamber 141 on at least one side of the second cover plate 122 with the outside, and the liquid injection channel 16 is used for injecting the electrolyte into the sealed chamber 141 communicated with the liquid injection channel 16 from the outside and is in a sealed state for blocking the communication between the outside and the sealed chamber 141 after the liquid injection is completed. It is understood that, according to practical circumstances, a liquid filling channel communicating with the sealing

chamber

141 or 142 on one side of the first cover plate 121 may be provided.

As shown in fig. 6, both ends of the liquid injection passage 16 are formed as a liquid injection port 161 and a liquid outlet port 162, respectively. The liquid inlet 161 is located on the circumferential surface 126 of the cover plate 12, and the liquid outlet 162 is located on the side surface 125 of the cover plate 12. The electrolyte is injected into the liquid injection passage 16 from the liquid injection port 161, and is injected into the sealed chamber from the liquid outlet port 162.

In the present application, the shape of the liquid injection channel 16 may be flexibly set, and may be, for example, a circular arc-shaped or curved cylindrical channel, or an L-shaped channel.

It will be appreciated that the filling channel 16 needs to be sealed after the electrolyte is filled into the sealed chamber. In one embodiment, as shown in fig. 6, the battery 100 further comprises a sealing member 17, wherein the sealing member 17 is used for sealing the liquid injection channel 16 after the liquid injection is completed. Wherein the block piece 17 can be at least partially located within the liquid injection channel 16.

In another embodiment, the second cover plate 122 may be protruded with a protrusion made of plastic, the liquid injection port 161 is disposed on the protrusion, and the liquid injection port 161 is sealed by hot melting after the liquid injection is completed.

In this application, through second apron 122 carries out sealing connection with two adjacent casings 11 to establish notes liquid passageway 16 on second apron 122, in case electrolyte leaks in one of them holding chamber 14, other holding chamber 14 remain intact, then still can not take place to leak because of the electrolyte and lead to the safety problem. In addition, the liquid injection channel 16 is formed in the second cover plate 122, and the liquid injection channel 16 is not formed in the housing 11, so that the sealing manner of the liquid injection channel 16 is relatively simple. After the liquid injection is completed, the liquid injection channel 16 on the cover plate 12 on the wall of the sealed chamber is in a sealed state, so that on one hand, the electrolyte in the sealed chamber does not flow out of the sealed chamber and is in contact with the shell 11 to cause internal short circuit, on the other hand, the electrolyte does not flow between the adjacent pole core accommodating cavities 14 and cannot affect each other, and the electrolyte cannot be decomposed due to overlarge potential difference, so that the safety and the service life of the battery 100 are ensured.

In the field of power batteries, the working condition consistency of each battery is crucial, and the performance of the whole battery pack is directly influenced. Similarly, the working condition consistency of each pole core group in the battery also influences the overall performance of each battery, and further influences the performance of the whole battery pack. The amount of electrolyte inside the battery will affect the performance of the battery, such as capacity, activity, etc. In the present application, the second cover plate 122 is provided with the liquid injection channel 16, so that the forming process of the battery 100 can be optimized under the condition of ensuring timely and effective infiltration of the electrolyte.

With respect to the manner in which the injection channels 16 are disposed, in one embodiment, one injection channel 16 may communicate with one sealed chamber, as shown in FIG. 6.

It should be noted that, when only one liquid injection channel 16 communicates with one sealed chamber, the liquid injection channel 16 needs to be disposed on each second cover plate 122. Annotate liquid many times through many times of opening, make every sealed room homoenergetic that holds utmost point core group have solitary passageway to pour into electrolyte into, can realize annotating the liquid route shortest, electrolyte can in time flow to the sealed indoor that corresponds by annotating the liquid passageway, guarantees that electrolyte in time soaks utmost point core group effectively, and the setting of a plurality of notes liquid passageways simultaneously, the content of electrolyte in every sealed room of control that can be accurate guarantees the uniformity of the electrolyte in a plurality of sealed rooms.

Alternatively, in another embodiment, as shown in fig. 3 or fig. 9, one liquid injection channel 16 may communicate with two adjacent sealed chambers at the same time.

Specifically, as shown in fig. 9, the liquid injection channel 16 includes a first channel 163 and a second channel 164, the first channel 163 penetrates through the second cover plate 122 where the first channel is located and communicates with two adjacent sealing chambers on two sides of the second cover plate 122, and the second channel 164 communicates the first channel 163 with the outside. That is, the circumferential surface 126 of the second cover plate 122 is provided with one liquid inlet 161, and both side surfaces 125 of the second cover plate 122 are provided with the liquid outlets 162.

The battery 100 further comprises a blocking piece 17, wherein the blocking piece 17 is used for sealing the second channel 164 after liquid injection is completed so as to block the communication between the second channel 164 and the outside, and is used for blocking at least one part of the area of the first channel 163 so as to block the communication between the first channel 163 and two adjacent sealing chambers.

It should be noted that, when the liquid injection channel 16 on one second cover plate 122 is simultaneously communicated with the sealed chambers on both sides of the second cover plate 122, the liquid injection channel 16 does not need to be arranged on each second cover plate 122, and the liquid injection channel 16 may be arranged on every other second cover plate 122.

In this embodiment, because the distance between the sealing chambers on the two sides of the second cover plate 122 is short, the liquid injection channel 16 on the second cover plate 122 can inject the electrolyte into the adjacent sealing chambers on the two sides of the second cover plate 122 at the same time, the infiltration path of the electrolyte is short, and the electrolyte can still effectively infiltrate the pole core groups 13 on the two sides in time.

Alternatively, in another embodiment, the number of the liquid injection channels 16 on each second cover plate 122 may be 1, or may be multiple.

For example, as shown in fig. 10, the liquid injection channel 16 includes a third channel 165 and a fourth channel 166 which are independent from each other, that is, two liquid injection channels are provided on one second cover plate 122. The third channel 165 communicates with the sealed chamber on one side of the second cover plate 122 where it is located, and the fourth channel 166 communicates with the sealed chamber on the other side of the second cover plate 122 where it is located.

Alternatively, in another embodiment, there is one liquid injection channel 16 corresponding to each sealed chamber, so that the amount of electrolyte injected into each sealed chamber can be accurately controlled, thereby ensuring the consistency of the electrolyte.

In one embodiment, as shown in fig. 11, at least one of the second cover plates 122 is provided with a liquid guiding through hole 18 for passing through the electrolyte, and the liquid guiding through hole 18 is used for communicating two adjacent sealed chambers on two sides of the second cover plate 122 where the liquid guiding through hole 18 is located. The fluid-guiding through hole 18 penetrates through two opposite side surfaces 125 of the second cover plate 122.

Specifically, in some embodiments, the liquid injection channel 16 and the liquid guiding through hole 18 are disposed on different second cover plates 122, wherein one of the two adjacent second cover plates 122 is provided with the liquid injection channel 16, and the other is provided with the liquid guiding through hole 18.

Optionally, in some embodiments, the liquid injection channel 16 and the liquid guiding through hole 18 are disposed on different second cover plates 122, wherein at least one of the second cover plates 122 is provided with the liquid injection channel 16, the liquid injection channel 16 communicates with two adjacent sealing chambers on two sides of the second cover plate 122 where the liquid injection channel is disposed, and the remaining second cover plates 122 are provided with the liquid guiding through hole 18.

Optionally, in some embodiments, at least one of the second cover plates 122 is provided with the liquid injection channel 16 and the liquid guiding through hole 18 communicated with the liquid injection channel 16, and the rest of the second cover plates 122 are provided with the liquid guiding through hole 18.

In one embodiment, as shown in fig. 12, the battery 100 further includes a sealing member 19, and the sealing member 19 is capable of blocking the liquid guiding through hole 18 after the liquid injection of the battery 100 is completed, so that the liquid guiding through hole 18 is in a closed state to block the communication between the liquid guiding through hole 18 and two adjacent sealing chambers. That is, after the liquid injection is completed, the sealing member 19 closes the liquid guide through hole 18 to isolate the adjacent two sealing chambers, so that the electrolyte does not flow between the adjacent sealing chambers, does not affect each other, and is not decomposed due to an excessive potential difference, thereby ensuring the safety and the service life of the battery 100.

In one embodiment, as shown in fig. 12 and 13, the second cover plate 122 further has a sealing channel 20 on the circumferential surface 126, the sealing channel 20 communicating with the fluid-guiding through hole 18 and penetrating through the fluid-guiding through hole 18, and the sealing member 19 can block the fluid-guiding through hole 18 under an external force.

In some embodiments, the seal 19 is a sealing plug and the sealing passage 20 matches the shape of the sealing plug.

As shown in fig. 12 and 13, the sealing member 19 has a rectangular parallelepiped structure. Alternatively, the sealing member 19 may have a cylindrical structure or a cylindrical structure having an elliptical cross-section. Wherein the shape of the sealing channel 20 can be flexibly arranged according to the shape of the sealing member 19.

Alternatively, as shown in fig. 14, 15 and 16, the sealing element 19 is a wedge-shaped block structure.

Alternatively, as shown in fig. 17, 18 and 19, the inner wall of the sealing channel 20 is provided with threads, and the sealing member 19 is a cylinder or a screw with threads on the surface.

Optionally, as shown in fig. 20, 21, and 22, the sealing member 19 is a cylindrical structure, and an elastic sealing ring 191 is sleeved on a portion corresponding to the liquid guiding through hole 18 in a sealing state.

In some embodiments, as shown in fig. 23, the seal 19 is a sealing ball, and includes a metal ball 192 and a sealing boot 193 covering an outer surface of the metal ball. Wherein the sealing ball is disposed within the sealing channel 20 in an interference fit.

In some embodiments, before, during, or after the injection of the battery 100, the sealing member 19 is in the first state, and the fluid-guiding through hole 18 is in a conducting state to communicate two adjacent sealing chambers on two sides of the second cover plate 122. After the battery 100 is injected with liquid or after the liquid is injected and formed, the sealing element 19 is switched from the first state to the second state, and the sealing element 19 blocks the liquid guiding through hole 18, so that the liquid guiding through hole 18 is in a closed state, and the communication of the liquid guiding through hole 18 to two adjacent sealing chambers is blocked. Wherein the seal 19 is switchable between the first condition and the second condition.

Specifically, the sealing channel 20 may have a first position and a second position formed therein, and the sealing member 19 may be movable between the first position and the second position by an external force. Wherein the first condition is the sealing member 19 being in the first position and the second condition is the sealing member 19 being in the second position. The external force is selected from one or more of gravity, electromagnetic force, inertia force or heat.

In the present application, the battery 100 may further include other structures, such as an explosion-proof valve, a current interrupt device, etc., and the other structures may refer to the conventional arrangement of the prior art and will not be described herein.

The present application also provides a battery module including the battery 100 of any of the above embodiments. Adopt the battery module that this application provided, assembly process is few, and the cost is lower.

As shown in fig. 24, the present application also provides a battery pack including a case 50 and the battery 100 or the battery module of any of the above embodiments. Wherein the battery 100 or the battery module is disposed inside the housing 50. The housing 50 may include a tray 51 and a cover 52, and a receiving cavity is formed between the tray and the cover for receiving the battery 100 or the battery module. By adopting the battery pack provided by the application, the assembly process is less, the cost is lower, and the energy density is higher.

The application also provides an electric vehicle adopting the battery pack as a power source. Due to the adoption of the battery pack provided by the application, the electric vehicle is high in endurance and low in cost.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In the description herein, references to the description of the terms "embodiment," "particular embodiment," "example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. The battery is characterized by comprising at least two shells, a plurality of cover plates and at least two pole core groups;

the at least two shells are sequentially arranged along a first direction of the battery;

the two opposite ends of each shell are respectively connected with the cover plate in a sealing manner to form an accommodating cavity;

each accommodating cavity is internally provided with the pole core group, the pole core group comprises at least one pole core, and the at least two pole core groups are connected in series;

the plurality of cover plates comprise two first cover plates and at least one second cover plate, wherein the second cover plate is arranged between the two first cover plates, and the adjacent two shells are fixedly and hermetically connected at the joint through the same second cover plate and are hermetically isolated from the containing cavities of the shells;

each accommodating cavity is connected with the corresponding cover plate through the corresponding shell in a sealing mode, so that a sealing chamber for accommodating and sealing the corresponding pole core group is formed;

the second cover plate is provided with a liquid injection channel which is communicated with the sealing chamber on at least one side of the second cover plate and the outside, the liquid injection channel is used for injecting electrolyte into the sealing chamber communicated with the liquid injection channel from the outside, and the sealing state of separating the outside from the communication of the sealing chamber is realized after liquid injection is finished.

2. The battery according to claim 1, wherein one of the first cover plates is provided at one end of the battery in the first direction, and the other of the first cover plates is provided at the other end of the battery in the first direction;

one end of the two opposite ends of the shell is connected with the first cover plate or the second cover plate in a sealing mode, and the other end of the shell is connected with the second cover plate in a sealing mode.

3. The battery of claim 2, wherein each accommodating cavity is provided with a pole core group, and the pole core groups in two adjacent accommodating cavities are connected in series; each pole core group comprises a first electrode leading-out part and a second electrode leading-out part which are used for leading out current, and the first electrode leading-out part and the second electrode leading-out part are respectively arranged on two opposite sides of the pole core group along the first direction;

and a connecting through hole is formed in the second cover plate, a first electrode leading-out part of one of the two adjacent electrode core groups in the accommodating cavity is electrically connected with a second electrode leading-out part of the other electrode core group, and the joint of the first electrode leading-out part and the second electrode leading-out part is positioned in the connecting through hole.

4. The battery of claim 3, further comprising an encapsulation structure disposed within the connection via, the encapsulation structure configured to encapsulate the connection within the connection via, and the encapsulation structure enclosing the connection via.

5. The battery of claim 3, wherein each accommodating cavity is provided with a pole core group, and the pole core groups in two adjacent accommodating cavities are connected in series; each pole core group comprises a first electrode leading-out part and a second electrode leading-out part which are used for leading out current, and the first electrode leading-out part and the second electrode leading-out part are respectively arranged on two opposite sides of the pole core group along the first direction;

the battery also comprises a pole core connecting piece, and the first electrode leading-out part of one of the pole core groups in the two adjacent accommodating cavities is electrically connected with the second electrode leading-out part of the other pole core group through the pole core connecting piece.

6. The battery of claim 5, wherein the pole piece connection extends through the second cover plate; and/or

The battery also comprises an encapsulation structure arranged in the connecting through hole, and the encapsulation structure is used for encapsulating the pole core connecting piece in the connecting through hole and sealing the connecting through hole; or, the pole core connecting piece and the second cover plate are integrally formed in an injection molding mode.

7. The battery according to claim 6, wherein the pole piece connecting member includes a copper connecting portion and an aluminum connecting portion electrically connected to each other, and the copper connecting portion and the aluminum connecting portion are electrically connected to each other at a position inside the second cap plate.

8. The battery of claim 2, wherein the chamber wall of each sealed chamber comprises a corresponding housing and a cover plate sealingly coupled to opposite ends of the corresponding housing.

9. The battery of claim 2, wherein the housing further comprises a separation film disposed in the accommodating cavity, opposite ends of the separation film are hermetically connected to cover plates disposed at opposite ends of the accommodating cavity, so as to form sealed chambers in the accommodating cavity, and the pole core groups are disposed in the corresponding sealed chambers in the accommodating cavity;

the cavity wall of each sealed chamber comprises a corresponding isolation film and a cover plate which is hermetically connected with two opposite ends of the corresponding isolation film.

10. The battery according to claim 1, wherein the liquid injection channel comprises a first channel and a second channel, the first channel penetrates through the second cover plate where the first channel is located and is communicated with two adjacent sealing chambers on two sides of the second cover plate, and the second channel is communicated with the first channel and the outside.

11. The battery of claim 10, further comprising a sealing member for sealing the second channel after completion of liquid injection to block the second channel from communicating with the outside; and at least one part of area of the first channel is blocked, so that the first channel can block the communication of two adjacent sealed chambers.

12. The battery according to claim 1, wherein the liquid injection channel comprises a third channel and a fourth channel which are independent of each other, the third channel is communicated with the sealing chamber on one side of the second cover plate where the third channel is located, and the fourth channel is communicated with the sealing chamber on the other side of the second cover plate where the fourth channel is located.

13. The battery according to claim 1, wherein at least one of the second cover plates is provided with a liquid guiding through hole for passing through electrolyte, and the liquid guiding through hole is used for communicating two adjacent sealing chambers on two sides of the second cover plate where the liquid guiding through hole is located.

14. The battery of claim 13, wherein the liquid injection channel and the liquid guiding through hole are arranged on different second cover plates, wherein one of the two adjacent second cover plates is provided with the liquid injection channel, and the other one is provided with the liquid guiding through hole; alternatively, the first and second electrodes may be,

the liquid injection channel and the liquid guide through hole are arranged on different second cover plates, wherein at least one second cover plate is provided with the liquid injection channel, the liquid injection channel is communicated with two adjacent sealing chambers on two sides of the second cover plate where the liquid injection channel is arranged, and the other second cover plates are provided with the liquid guide through holes; or

And at least one second cover plate is simultaneously provided with the liquid injection channel and a liquid guide through hole communicated with the liquid injection channel, and the rest second cover plates are provided with the liquid guide through holes.

15. The battery of claim 1, further comprising a sealing member for sealing the liquid injection channel after completion of liquid injection.

16. The battery according to claim 1, wherein both ends of the liquid injection passage are respectively formed as a liquid injection port from which the electrolyte is injected into the liquid injection passage and a liquid outlet from which the electrolyte is injected into the sealed chamber;

the outside protrusion of second apron has the bulge, the bulge is made by plastics, annotate the liquid mouth and establish on the bulge, annotate the liquid mouth and adopt the hot melt sealed after annotating the liquid and accomplish.

17. The battery of claim 13, further comprising a sealing member capable of blocking the fluid-conducting through hole after the battery is filled with fluid, so that the fluid-conducting through hole is in a closed state to block the communication of the fluid-conducting through hole to two adjacent sealing chambers.

18. The battery of claim 17, wherein the second cap plate includes a side surface facing the adjacent pole core group and a circumferential surface connected to the side surface;

the liquid guide through hole penetrates through two opposite side surfaces of the second cover plate;

the second apron is in still be equipped with on the circumference face with drain through-hole intercommunication and run through the sealed passageway of drain through-hole, the sealing member can block under the exogenic action drain through-hole.

19. The cell defined in claim 18, wherein the seal is a sealing plug and the sealing channel matches the shape of the sealing plug.

20. The battery of claim 19, wherein the sealing plug is of a rectangular parallelepiped configuration, a cylindrical configuration with an oval cross-section, or a wedge configuration; or

Threads are arranged on the inner wall of the sealing channel, and the sealing plug is a cylinder or a screw with threads on the surface; or

The sealing element is of a columnar structure, and an elastic sealing ring is sleeved on a position corresponding to the liquid guide through hole in a sealing state.

21. The battery of claim 18, wherein the seal is a sealing ball comprising a metal ball and a sealing boot surrounding an outer surface of the metal ball.

22. The battery of claim 18, wherein the sealing member is in a first condition before, during, or after the battery is formed by filling, and the fluid-conducting through hole is in a conducting state to communicate two adjacent sealing chambers on two sides of the second cover plate where the fluid-conducting through hole is located; after the battery is injected with liquid or after the battery is formed by injection, the sealing element is switched from the first condition to the second condition, and the sealing element blocks the liquid guide through hole to enable the liquid guide through hole to be in a closed state so as to block the communication of the liquid guide through hole to two adjacent sealing chambers; wherein the seal is switchable between the first condition and the second condition.

23. The cell of claim 22 wherein a first position and a second position are formed within the sealing channel and the sealing member is movable between the first position and the second position under an external force;

the first condition is the seal being in the first position; the second condition is the seal being in the second position.

24. The battery of claim 23, wherein the external force is selected from one or more of gravity, electromagnetic force, inertial force, or thermal force.

25. The battery according to claim 1 or 2, wherein the cap plate includes a side surface facing the adjacent pole core group and a circumferential surface connected to the side surface, the circumferential surface being flush with the outer surface of the case.

26. The battery of claim 25, wherein the circumferential surfaces include a first circumferential surface and a second circumferential surface projecting from the first circumferential surface, the second circumferential surface being flush with an outer surface of the housing;

the end part of the shell extends outwards to form a butting part, and the butting part is butted on the first circumferential surface of the cover plate fixedly connected with the butting part.

27. The battery of claim 1, wherein the cover plate is made of an insulating material; and/or the presence of a gas in the gas,

the shell is a metal shell with an insulated inner surface; and/or the presence of a gas in the gas,

the battery is a lithium ion battery.

28. A battery module comprising the battery according to any one of claims 1 to 27.

29. A battery pack comprising the battery according to any one of claims 1 to 27 or the battery module according to claim 28.

30. An electric vehicle comprising the battery pack according to claim 29, the battery module according to claim 28, or the battery according to any one of claims 1 to 27.