Battery cell and battery with same

Abstract

The invention provides a battery cell and a battery with the same. The battery cell comprises a shell, a cap assembly and a roll core. The shell is of a slender structure and is provided with an opening in the top end, the cap assembly is packaged at the opening of the shell and defines a containing space together with the shell, and the roll core is contained in the containing space in a shape matched mode. The cap assembly and the roll core are in direct contact and are fixedly connected, so that direct electric conduction between the roll core and the cap assembly is achieved. According to the invention, a confluence sheet between a conventional roll core and a cap assembly is omitted, so that the space is saved. And under the condition that the length of the battery is fixed, the roll core can be lengthened, and the capacity can be improved. As the roll core and the cap assembly are directly and conductively connected, the electron transmission path is shortened, the internal resistance is reduced, and the power supply efficiency of the battery is improved.

Description

Technical Field

[0001] This invention relates to the field of batteries, and more specifically to a battery cell and a battery having the battery cell. Background Technology

[0002] Currently, common battery cells on the market consist of a core and a casing. The core is usually housed within the casing to prevent damage. The casing typically comprises a cylindrical body with an opening on one side and a cap assembly to seal the opening. The cap assembly usually requires grooves, or grooves, to be engraved on the cylindrical body to seal the opening. With fixed battery specifications, the internal space of the casing is limited. The presence of the cap assembly, grooves, and other components occupies a portion of this space, leaving less room for the core and thus limiting the cell's capacity. Furthermore, the inclusion of busbars within the cell further occupies space within the casing, compressing the core's space and hindering capacity increases. These structural features also complicate the cell manufacturing process, increasing production costs. In addition, there is a market demand for low-internal-resistance batteries, and the safety performance of existing batteries needs improvement.

[0003] Therefore, there is a need to provide a battery cell and a battery having the battery cell to at least partially solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a battery cell and a battery having the same cell. In this invention, the core and cap assembly of the battery cell are directly welded together and electrically connected, eliminating the need for a conventional busbar between the core and cap assembly, thus saving space. With a fixed battery length, this design allows for a longer core, increasing capacity. Because the core and cap assembly are directly electrically connected, the electron transport path is shortened, reducing internal resistance and improving battery power efficiency.

[0005] Furthermore, the cap assembly of the battery cell of the present invention has a unique sealing structure in the circumferential direction. This sealing structure ensures a tight fit between the cap assembly and the outer casing, effectively improving the stability of the battery cell and extending its service life. The present invention also provides some preferred configurations for the explosion-proof valve and the electrolyte injection port, improving the overall performance of the battery cell, especially its safety performance, in multiple aspects.

[0006] According to one aspect of the present invention, a battery cell is provided, the battery cell comprising:

[0007] The outer casing is elongated and has an opening at the top.

[0008] A cap assembly, which is encapsulated at the opening of the housing and together with the housing defines an accommodating space, and

[0009] A winding core, the shape of which is adapted to be accommodated within the accommodating space.

[0010] The cap assembly and the core are in direct contact and fixedly connected to achieve direct electrical conduction between the core and the cap assembly.

[0011] In one embodiment, the cap assembly is integrally formed as a flat plate structure, and the entire top surface of the core is in surface contact with the cap assembly.

[0012] In one embodiment, the cap assembly includes a cap body that substantially covers the opening, an annular plate surrounding the cap body, and an annular sealing ring fitted between the annular plate and the cap body and electrically isolating the annular plate and the cap body.

[0013] The core and the cap body are fixedly connected, and the side wall of the outer shell and the annular plate are fixedly connected. In particular, the core and the cap body are connected by welding, and the side wall of the outer shell and the annular plate are connected by welding.

[0014] In one embodiment, the cap body and the sealing ring are provided with a matching structure at the connection point, the sealing ring and the annular plate are provided with a matching structure at the connection point, and the annular plate and the side wall of the outer shell are provided with a matching structure at the connection point.

[0015] In one embodiment, the circumferential side of the cap body is provided with a first receiving groove that opens outward and extends integrally in the circumferential direction, and at least a portion of the sealing ring is placed in the first receiving groove.

[0016] Specifically, the sealing ring is provided with a second receiving groove opening outwards along its entire circumference, and at least a portion of the annular plate is placed in the second receiving groove.

[0017] Preferably, the radially inner end of the annular plate is inserted into the second receiving groove and, together with at least a portion of the sealing ring, is inserted into the first receiving groove.

[0018] In one embodiment, the sealing ring has a top wall defining the second receiving groove, a bottom wall defining the second receiving groove, and a side wall defining the top wall and the bottom wall defining the second receiving groove, wherein the top wall and the bottom wall defining the second receiving groove extend radially outward beyond the cap body, and preferably the top wall, the bottom wall and the side wall defining the second receiving groove have equal thicknesses.

[0019] In one embodiment, the annular plate engages with the sealing ring in an interference fit, and / or the sealing ring engages with the cap body in an interference fit.

[0020] Specifically, both the annular plate and the cap body are formed as flat plates of uniform thickness.

[0021] In one embodiment, the sidewall of the outer casing has a first stepped structure at the opening end of the outer casing, and the bottom circumferential position of the annular plate also has a second stepped structure, the first stepped structure and the second stepped structure being in concave-convex fit.

[0022] Preferably, the first step structure includes radially adjacent outer and inner steps, the outer step projecting upward relative to the inner step.

[0023] In one embodiment, the cap assembly is provided with an electrolyte inlet penetrating the cap body, and the cap assembly further includes an inlet cover for covering the electrolyte inlet.

[0024] Specifically, the core and the cap body are welded together along a welding trajectory, and the electrolyte inlet is arranged to bypass the welding trajectory. Specifically, the welding trajectory is radial, discrete dotted, spiral, or concentric circular, extending along the cap body.

[0025] Specifically, the electrolyte inlet is located at the center of the cap body or near the edge of the cap body.

[0026] In one embodiment, the housing and / or the cap assembly are provided with a thinned region serving as an explosion-proof valve, preferably the thickness of the thinned region being 40-90% of the thickness of its adjacent region.

[0027] Specifically, the sidewall of the housing is provided with a circumferentially extending groove as an explosion-proof valve, preferably the groove is located at the axial center of the sidewall of the housing.

[0028] Specifically, the cap assembly includes an inlet cover for covering the electrolyte inlet, the thickness of which is less than the thickness of the cap body, so that the inlet cover functions as an explosion-proof valve.

[0029] In one embodiment, the bottom end of the winding core is fixedly connected to the bottom wall of the outer casing to achieve direct electrical conduction between the bottom wall of the outer casing and the winding core.

[0030] Specifically, there is no busbar between the top of the core and the cap assembly.

[0031] Specifically, there is no busbar between the bottom end of the core and the bottom wall of the outer casing.

[0032] According to another aspect of the present invention, a battery is provided, the battery comprising a cell according to any one of the above embodiments, particularly a plurality of cells arranged in an array in a plane perpendicular to the axial direction of the cells. Attached Figure Description

[0033] To better understand the above and other objects, features, advantages, and functions of the present invention, reference can be made to the preferred embodiments shown in the accompanying drawings. The same reference numerals in the drawings refer to the same parts. Those skilled in the art should understand that the drawings are intended to schematically illustrate preferred embodiments of the invention and do not limit the scope of the invention in any way; the parts in the drawings are not drawn to scale.

[0034] Figure 1 A three-dimensional schematic diagram of a battery cell according to a preferred embodiment of the present invention;

[0035] Figure 2 for Figure 1 A partially exploded diagram showing the core housed within the outer casing;

[0036] Figure 3 for Figure 1 An exploded view of the cap assembly;

[0037] Figure 4 for Figure 1 A cross-sectional view taken along line AA;

[0038] Figure 5 for Figure 4 A magnified view of part B in the image.

[0039] Figure label:

[0040] 100 cells

[0041] 11 rolls

[0042] 111 Through Hole

[0043] 112 tubular body

[0044] 12 shells

[0045] 121 groove

[0046] 122 First Step Structure

[0047] 1221 Outer Steps

[0048] 1222 Inner Step

[0049] 123 Side walls of the outer casing

[0050] 124 bottom wall of the outer casing

[0051] 125 opening

[0052] 13-cap assembly

[0053] 131 Cap Body

[0054] 1311 First Receiving Tank

[0055] 1312 Electrolyte Inlet

[0056] 1313 welding trajectory

[0057] 132 sealing ring

[0058] 1321 Second Reception Tank

[0059] 1322 sealing ring top wall

[0060] 1323 sealing ring bottom wall

[0061] 1324 sealing ring sidewall

[0062] 133 Ring Plate

[0063] 1331 Second Step Structure

[0064] The radial inner end of the 1332 annular plate

[0065] 134 Inlet Cover Plate Detailed Implementation

[0066] Now, with reference to the accompanying drawings, specific embodiments of the present invention will be described in detail. The embodiments described herein are merely preferred embodiments of the invention; those skilled in the art will conceive of other ways to implement the invention based on these preferred embodiments, and such other ways also fall within the scope of the invention.

[0067] The present invention provides a battery cell and a battery having the battery cell. Figures 1-5 The illustration shows a battery cell according to some preferred embodiments of the present invention. It should be noted that the directional and positional terms used in this invention are only used to describe relative directions and positions, not absolute directions and positions. These directions and positions can be referenced... Figures 1-5 The placement orientation of the battery cells shown can be used to understand this.

[0068] The terms "axial direction" and "axial direction" mentioned in this invention refer to, for example, the axial direction of a cylindrical battery cell. Figure 1The cell is indicated by X. The cell may not be cylindrical; it can also be prism or cube. Accordingly, "axial" or "axial direction" can be understood as the direction extending along the length of the cell and passing through its center. In this invention, "radial" and "circumferential" refer to the radial and circumferential directions with respect to the axial direction X. In this invention, "top side" or "top end" refers to the side of the elongated cell with the cap assembly, and "bottom side" or "bottom end" refers to the side of the cell opposite to the cap assembly. "Top side" and "bottom side" are only relative concepts; for example, even if... Figure 1 The battery cells are flipped upside down, and the side with the cap assembly is still referred to as the top side.

[0069] First refer to Figure 1 and Figure 2 The battery cell 100 includes a housing 12, a core 11, and a cap assembly 13. The housing 12 has an elongated shape and an opening 125 at its top, and the cap assembly 13 is encapsulated in the opening 125. In some embodiments, the housing 12 is formed as a generally standard cylinder; in other embodiments, the housing 12 can be a prism or a cube. The core 11 is shape-fittedly housed within the housing 12, from which… Figure 2 As can be seen from this, the outer diameter of the core 11 is approximately equal to the inner diameter of the outer shell 12, and the top of the core 11 is approximately the same as the side wall 123 of the outer shell 12 (see...). Figure 4 The top of the core is flush with the top, meaning that the core 11 completely fills the receiving space defined by the outer casing 12 and the cap assembly 13.

[0070] The cap assembly 13 and the core 11 are directly and fixedly connected to achieve direct electrical conduction between them. It should be noted that "direct contact and fixed connection" in this invention means that the core 11 and the cap assembly 13 are directly bonded together, without any other primary connecting or conductive medium between them; electrical transmission is achieved through the direct contact between the core 11 and the cap assembly 13. For example... Figure 2 As shown, the cap assembly 13 is integrally formed as a flat plate structure, with the entire top surface of the core 11 in surface contact with the cap assembly 13. This large-area surface contact enables electrical transmission between the core 11 and the cap assembly 13. The flat plate structure of the cap assembly 13 greatly saves the space occupied by the cap assembly 13 in the axial direction, which helps to increase the capacity of the battery cell.

[0071] Compared to the traditional configuration where a busbar is placed between the core 11 and the cap assembly 13, the configuration of the present invention, where the core 11 and the cap assembly 13 are in direct contact and directly conduct electricity, saves space. Therefore, with a fixed battery length, the core 11 can be made longer, and the capacity can be increased. Since the core 11 and the cap assembly 13 are directly electrically connected, the electron transmission path is also shortened, the internal resistance of the cell 100 is reduced, and the battery power supply efficiency is improved.

[0072] refer to Figure 3 The cap assembly 13 includes a circular cap body 131 that almost completely covers the opening 125, an annular plate 133 surrounding the cap body 131, and an annular sealing ring 132 fitted between the annular plate 133 and the cap body 131 and electrically isolating the annular plate 133 and the cap body 131. The core 11 is fixedly connected to the cap body 131, and the sidewall 123 of the outer shell 12 is fixedly connected to the annular plate 133. The cap body 131 is a flat plate of uniform thickness, and preferably the annular plate 133 is also a flat plate of uniform thickness, with the thickness of the annular plate 133 being less than the thickness of the cap body 131.

[0073] Specifically, the core 11 and the cap body 131 are connected by welding, and the side wall 123 of the outer shell 12 and the annular plate 133 are connected by welding. More preferably, the welding method is laser welding. Figure 3 The diagram shows a welding trajectory 1313 for welding the cap body 131 to the core 11. The welding trajectory 1313 is radial, extending along the entire flat structure of the cap body 131 (e.g., with the center of the cap body 131 as the radial center). In other embodiments not shown, the welding trajectory may also be discrete dots, spirals, or concentric circles. In some other embodiments, the cap assembly 13 can be fixed to the top surface of the core 11 by riveting, bonding, or other means. The sidewalls 123 of the outer shell 12 and the annular plate 133 can also be connected by riveting, bonding, or other means.

[0074] Furthermore, the sealing ring 132 is made of conductive insulating material, thus not only preventing electrolyte leakage from the battery cell 100, but also electrically isolating the cap body 131 and the annular plate 133. Specifically, the top end of the battery cell 100 is in conductive contact with the cap body 131, so the cap body 131 and the top end of the battery cell 100 have the same polarity (e.g., positive); the bottom end of the battery cell 100 is in conductive contact with the bottom wall 124 of the outer casing 12, and the outer casing 12 is in conductive contact with the annular plate 133, so the annular plate 133 and the bottom end of the battery cell 100 have the same polarity (e.g., negative). The sealing ring 132 electrically isolates the cap body 131 and the annular plate 133, ensuring the effective and stable operation of the battery cell 100 and preventing short circuits between the positive and negative terminals.

[0075] In some embodiments, preferred configurations of the sealing structure between the cap assembly 13 and the housing 12 are also provided, including preferred configurations of the joint structure between the cap body 131 and the sealing ring 132 of the cap assembly 13, preferred configurations of the joint structure between the sealing ring 132 and the annular plate 133, and preferred configurations of the joint structure between the annular plate 133 and the housing 12. Specifically, the cap body 131 and the sealing ring 132 are provided with mutually matching structures at the connection point, the sealing ring 132 and the annular plate 133 are also provided with mutually matching structures at the connection point, and the annular plate 133 and the top of the side wall 123 of the housing 12 are also provided with mutually matching structures. The mutually matching structures can have various embodiments as follows.

[0076] In some implementations, such as Figures 3-5 As shown, the cap body 131 has a first receiving groove 1311 that opens outward and extends integrally in the circumferential direction on its side, and at least a portion of the sealing ring 132 is placed in the first receiving groove 1311. The sealing ring 132 has a second receiving groove 1321 that opens outward in the circumferential direction, and at least a portion of the annular plate 133 is placed in the second receiving groove 1321. The sealing ring 132 has a sealing ring top wall 1322, a sealing ring bottom wall 1323 defining the second receiving groove 1321, and a sealing ring side wall 1324 connecting the sealing ring top wall 1322 and the sealing ring bottom wall 1323. The sealing ring top wall 1322, the sealing ring bottom wall 1323, and the sealing ring side wall 1324 have equal thicknesses. Preferably, the sealing ring 132 may consist only of the sealing ring top wall 1322, the sealing ring bottom wall 1323, and the sealing ring side wall 1324 without other structures.

[0077] Preferably, the radially inner end 1332 of the annular plate 133 is inserted into the second receiving groove 1321 and, together with at least a portion of the sealing ring 132, is inserted into the first receiving groove 1311. This arrangement ensures that the cap body 131, the sealing ring 132, and the annular plate 133 are all engaged, resulting in a compact and stable cap assembly structure. The annular plate 133 engages with the sealing ring 132 via an interference fit, and / or the sealing ring 132 engages with the cap body 131 via an interference fit.

[0078] Preferably, both the top wall 1322 and the bottom wall 1323 of the sealing ring extend radially outward beyond the cap body 131. This arrangement can further ensure the electrical insulation between the cap body 131 and the annular plate 133.

[0079] Continue to refer to Figure 5The sidewall 123 of the outer casing 12 has a first stepped structure 122 at the open end of the outer casing 12, and a second stepped structure 1331 is also provided at the bottom circumferential position of the annular plate 133. The first stepped structure 122 and the second stepped structure 1331 are in a concave-convex fit. Preferably, the first stepped structure 122 includes an outer stepped step 1221 and an inner stepped step 1222 that are adjacent in the radial direction. The outer stepped step 1221 protrudes towards the top relative to the inner stepped step 1222. This arrangement facilitates the assembly between the outer casing 12 and the annular plate 133.

[0080] In addition to the embodiments described above, other joint structures may be provided between the components in other embodiments not shown. For example, in one embodiment, the thickness of the annular plate may be greater than the thickness of the cap body, and a receiving groove may be provided on the circumferential inner side of the annular plate, into which the radial outer end of the cap body, together with the sealing ring, may be inserted.

[0081] Continue to refer to Figures 3-5 The cap assembly 13 is provided with an electrolyte inlet 1312 penetrating the cap body 131. The cap assembly 13 also includes an inlet cover plate 134 for covering the electrolyte inlet 1312, and the electrolyte inlet 1312 is arranged to bypass the welding trajectory. Figure 2 and Figure 4 As shown, the core 11 includes a cylindrical body 112 and a through hole 111 at the center of the cylindrical body, through which electrolyte can enter the through hole 111 via an electrolyte inlet 1312. In the embodiment shown in the figure, the electrolyte inlet 1312 is located near the edge of the cap body 131, but in other preferred embodiments, the electrolyte inlet can be located at the center of the cap body. The radial dimension of the inlet cover plate 134 is larger than that of the electrolyte inlet 1312, and the thickness of the inlet cover plate 134 is smaller than the height of the hole defining the electrolyte inlet 1312.

[0082] To enhance the safety performance of the battery cell 100, the housing 12 and / or cap assembly 13 are provided with a thinned region serving as an explosion-proof valve. Preferably, the thickness of the thinned region is 40-90% of the thickness of its adjacent region. When the pressure inside the battery cell 100 exceeds a threshold (e.g., 1.0 MKPa), the pressure can be released by breaking through this region, preventing an explosion. Reference Figure 1 and Figure 4 The side wall 123 of the housing 12 is provided with a circumferentially extending (preferably continuously extending) groove 121 to serve as an explosion-proof valve. Preferably, the groove 121 is located at the axial center of the side wall 123 of the housing 12. As a supplement or alternative to this explosion-proof valve, the thickness of the inlet cover 134 covering the electrolyte inlet is also less than the thickness of the cap body 131, so the inlet cover 134 can also be used as an explosion-proof valve.

[0083] In some preferred embodiments, the bottom end of the battery cell 100 and the bottom wall 124 of the outer casing 12 can also be directly contacted and fixedly connected to achieve a conductive connection between them. A busbar may not be provided between the bottom end of the core 11 and the bottom wall 124 of the outer casing 12. As mentioned above, the top end of the core 11 can be, for example, the positive electrode of the core 11, and the bottom end of the core 11 can be, for example, the negative electrode of the core 11. Therefore, a positive electrode busbar is omitted between the top end of the core 11 and the cap assembly 13, and a negative electrode busbar is omitted between the bottom end of the core 11 and the bottom wall 124 of the outer casing 12.

[0084] The materials of the various components in the above embodiments may also have some preferred settings. For example, the outer shell 12 is made of copper, iron, aluminum, nickel, carbon steel, alloy steel, copper alloy, aluminum alloy, nickel alloy, or titanium alloy, preferably carbon steel or alloy steel; the sealing ring 132 is made of rubber (e.g., natural rubber, neoprene rubber, nitrile rubber, styrene-butadiene rubber, EPDM rubber, or fluororubber) or engineering plastics (e.g., polytetrafluoroethylene, perfluoroethylene propylene, polyvinylidene fluoride, or tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer); the annular plate 133 is made of copper, iron, aluminum, nickel, carbon steel, alloy steel, copper alloy, aluminum alloy, nickel alloy, or titanium alloy, preferably carbon steel or alloy steel; the cap body 131 is made of copper, iron, aluminum, nickel, carbon steel, alloy steel, copper alloy, aluminum alloy, nickel alloy, or titanium alloy, preferably carbon steel or alloy steel; the inlet cover 134 is made of copper, iron, aluminum, nickel, carbon steel, alloy steel, copper alloy, aluminum alloy, nickel alloy, or titanium alloy, preferably carbon steel or alloy steel.

[0085] The present invention also provides a battery, which may include one or more battery cells 100 according to the above embodiments. When there are multiple battery cells 100, the multiple battery cells 100 may be arranged in an array in a plane perpendicular to the axial direction X. The embodiments relating to battery cells 100 described above should also be considered as embodiments relating to the battery.

[0086] In this invention, the core and cap assembly of the battery cell are directly welded and fixed together for conductive connection, eliminating the need for a busbar between the conventional core and cap assembly, thus saving space. With a fixed battery length, this arrangement allows for a longer core and increased capacity. Because the core and cap assembly are directly conductively connected, the electron transmission path is shortened, reducing the internal resistance of the battery cell and improving battery power efficiency. Furthermore, the cap assembly of the battery cell in this invention has a unique sealing structure in the circumferential direction, which ensures a tight fit between the cap assembly and the outer casing, effectively improving the stability of the battery cell and extending its service life. This invention also provides preferred configurations for the explosion-proof valve and electrolyte injection port, improving the overall performance of the battery cell, especially its safety performance, in multiple aspects.

[0087] The above description of various embodiments of the present invention is provided for illustrative purposes to a person skilled in the art. It is not intended to limit the invention to a single disclosed embodiment. As taught above, those skilled in the art will understand various alternatives and variations of the invention. Therefore, although some alternative embodiments have been specifically described, those skilled in the art will understand or relatively easily develop other embodiments. The present invention is intended to include all alternatives, modifications, and variations of the invention described herein, as well as other embodiments falling within the spirit and scope of the invention described above.

Claims

1. A battery cell (100), characterized in that, The battery cell (100) includes: The outer shell (12) is elongated and has an opening (125) at the top. A cap assembly (13) is encapsulated in the opening (125) of the housing (12) and together with the housing defines an accommodating space. Core (11), the core shape being adapted to be accommodated in the accommodating space, The cap assembly (13) and the core (12) are in direct contact and fixedly connected to achieve direct electrical conduction between the core (11) and the cap assembly (13).

2. The battery cell according to claim 1, characterized in that, The cap assembly (13) is formed as a flat plate structure, and the entire top surface of the core (11) is in contact with the cap assembly (13).

3. The battery cell according to claim 1 or 2, characterized in that, The cap assembly (13) includes a cap body (131) that almost covers the opening (125), an annular plate (133) surrounding the cap body, and an annular sealing ring (132) fitted between the annular plate (133) and the cap body (131) and electrically isolating the annular plate (133) and the cap body (131). The core (11) and the cap body (131) are fixedly connected, and the side wall (123) of the outer shell (12) and the annular plate (133) are fixedly connected. In particular, the core (11) and the cap body (131) are connected by welding, and the side wall (123) of the outer shell (12) and the annular plate (133) are connected by welding.

4. The battery cell according to claim 3, characterized in that, The cap body (131) and the sealing ring (132) are provided with a matching structure at the connection point. The sealing ring (132) and the annular plate (133) are provided with a matching structure at the connection point. The annular plate (133) and the side wall (123) of the outer shell (12) are provided with a matching structure at the connection point.

5. The battery cell according to claim 3 or 4, characterized in that, The cap body (131) has a first receiving groove (1311) that opens outward and extends integrally in the circumferential direction on its circumferential side. At least a portion of the sealing ring (132) is placed in the first receiving groove (1311). Specifically, the sealing ring (132) is provided with a second receiving groove (1321) opening outwards along its entire circumference, and at least a portion of the annular plate (133) is placed in the second receiving groove (1321). Preferably, the radial inner end (1332) of the annular plate (133) is inserted into the second receiving groove (1321) and together with at least a portion of the sealing ring (132), is inserted into the first receiving groove (1311).

6. The battery cell according to claim 5, characterized in that, The sealing ring (132) has a top wall (1322) defining the second receiving groove (1321), a bottom wall (1323) defining the second receiving groove (1321), and a side wall (1324) connecting the top wall and the bottom wall, wherein the top wall (1322) and the bottom wall (1323) extend radially outward beyond the cap body (131), and preferably the top wall (1322), the bottom wall (1323) and the side wall (1324) have equal thickness.

7. The battery cell according to claim 5 or 6, characterized in that, The annular plate (133) engages with the sealing ring (132) in an interference fit, and / or the sealing ring (132) engages with the cap body (131) in an interference fit. Specifically, both the annular plate (133) and the cap body (131) are formed as flat plates of uniform thickness.

8. The battery cell according to any one of claims 3-7, characterized in that, The sidewall (123) of the outer shell (12) has a first stepped structure (122) at the opening end of the outer shell, and the bottom circumferential position of the annular plate (133) is also provided with a second stepped structure (1331). The first stepped structure (122) and the second stepped structure (1331) are in concave-convex fit. Preferably, the first step structure (122) includes an outer step (1221) and an inner step (1222) that are radially adjacent, the outer step (1221) protruding toward the top relative to the inner step (1222).

9. The battery cell according to any one of claims 2-8, characterized in that, The cap assembly (13) is provided with an electrolyte inlet (1312) penetrating the cap body (131), and the cap assembly (13) further includes an inlet cover plate (134) for covering the electrolyte inlet (1312). Specifically, the core (11) and the cap body (131) are welded together along a welding trajectory (1313), and the electrolyte inlet (1312) is arranged around the welding trajectory (1313). In particular, the welding trajectory is radial, discrete dotted, spiral, or concentric circular extending along the cap body. Specifically, the electrolyte inlet (1312) is located at the center of the cap body (131) or near the edge of the cap body.

10. The battery cell according to any one of claims 3-9, characterized in that, The outer casing (12) and / or the cap assembly (13) are provided with a thinned region serving as an explosion-proof valve, preferably the thickness of the thinned region being 40-90% of the thickness of its adjacent region. Specifically, the sidewall (123) of the outer casing (12) is provided with a circumferentially extending groove (121) as an explosion-proof valve. Preferably, the groove (121) is located at the axial center of the sidewall (123) of the outer casing (12). Specifically, the cap assembly (13) includes an inlet cover (134) for covering the electrolyte inlet (1312), the thickness of the inlet cover (134) being less than the thickness of the cap body (131) so that the inlet cover (134) functions as an explosion-proof valve.

11. The battery cell according to any one of claims 1-10, characterized in that, The bottom end of the core (11) and the bottom wall (124) of the outer shell (12) are fixedly connected to achieve direct electrical conduction between the bottom wall (124) of the outer shell (12) and the core (11). Specifically, there is no busbar between the top of the core (11) and the cap assembly (13). Specifically, there is no busbar between the bottom end of the core (11) and the bottom wall (124) of the outer shell (12).

12. A battery, characterized in that, The battery includes a cell (100) according to any one of claims 1-11, and in particular, there are multiple cells arranged in an array in a plane perpendicular to the axial direction (X) of the cells.

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