Battery cell and battery pack

Abstract

The application discloses a battery monomer and a battery pack, the battery monomer comprises a shell, a pole group is arranged in the shell, the pole group is a plurality of intervals along a first direction, any two adjacent pole groups are a first pole group and a second pole group, the first pole group has a first pole lug at one end close to the second pole group, and the second pole group has a second pole lug at one end close to the first pole group; a series structure is arranged between any two adjacent pole groups, and the first pole lug and the second pole lug are connected with the series structure to connect the two adjacent pole groups in series. According to the battery monomer, the energy density of the battery monomer is improved, the space of the battery pack is saved, the energy density of the battery pack is high, and the internal electrochemical consistency of the battery monomer is high, so that the battery monomer is safer and more reliable.

Description

Technical Field

[0001] This invention relates to the field of battery pack technology, and more particularly to a battery cell and a battery pack. Background Technology

[0002] Currently, blade batteries are available on the market, ranging in size from 300-1300mm. Shorter lengths require more cells to be connected in series along the length of the battery pack, resulting in gaps for assembly and electrical connections. This reduces space utilization and consequently lowers the energy density of the battery pack. Conversely, longer electrode arrays within each cell, while saving space and increasing energy density, lead to poorer electrochemical consistency within the cells along the length, increasing the risk of lithium plating thermal runaway. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a battery cell that improves the energy density of the battery cell, saves space in the battery pack, results in a high energy density for the battery pack, and simultaneously provides high internal electrochemical consistency within the battery cell, making it safer and more reliable.

[0004] The present invention also proposes a battery pack comprising the aforementioned battery cells.

[0005] A battery cell according to an embodiment of the present invention includes: a housing; electrode groups disposed within the housing, wherein the electrode groups are a plurality of electrode groups spaced apart along a first direction, one of any two adjacent electrode groups is a first electrode group and the other is a second electrode group, the first electrode group has a first tab at the end near the second electrode group, and the second electrode group has a second tab at the end near the first electrode group; and a series structure, wherein the series structure is provided between any two adjacent electrode groups, and the first tab and the second tab are both connected to the series structure to connect the two adjacent electrode groups in series.

[0006] According to an embodiment of the present invention, a battery cell comprises a plurality of electrode groups spaced apart along a first direction disposed within a housing. Any two adjacent electrode groups are designated as a first electrode group and a second electrode group, respectively. The ends of the first and second electrode groups closest to each other have a first tab and a second tab, respectively. A series connection structure is provided between any two adjacent electrode groups, and both the first tab and the second tab are connected to the series connection structure to link the adjacent electrode groups in series. This improves the energy density of the battery cell, saves space in the battery pack, results in a high energy density for the battery pack, and ensures high internal electrochemical consistency within the battery cell, making it safer and more reliable.

[0007] In some embodiments of the present invention, the series structure includes: a first connecting plate connected to the first electrode tab; a second connecting plate connected to the second electrode tab and the first connecting plate, wherein both the first connecting plate and the second connecting plate are conductive components.

[0008] In some embodiments of the present invention, the first connecting plate and the second connecting plate are spaced apart, and the series structure further includes: a pole post, which is disposed between the first connecting plate and the second connecting plate, and the two ends of the pole post are respectively connected to the first connecting plate and the second connecting plate.

[0009] In some embodiments of the present invention, the series structure further includes: a series structure plate, the series structure plate being fixed to the housing, the series structure plate having mounting holes, the pole passing through the mounting holes, and the first connecting plate and the second connecting plate being located on both sides of the series structure plate.

[0010] In some embodiments of the present invention, the series structure plate is a metal part, and insulating seals are provided between the series structure plate and the pole, between the series structure plate and the first connecting plate, and between the series structure plate and the second connecting plate.

[0011] In some embodiments of the present invention, the insulating seal includes: a sealing ring disposed between the outer peripheral wall of the pole post and the inner peripheral wall of the mounting hole; a first insulating member disposed at least partially between the first connecting plate and the series structure plate; and a second insulating member disposed at least partially between the second connecting plate and the series structure plate.

[0012] In some embodiments of the present invention, the first insulating member has a first mounting groove on the side opposite to the series structure plate, and at least a portion of the first connecting plate is disposed in the first mounting groove along the thickness direction of the first connecting plate; and / or, the second insulating member has a second mounting groove on the side opposite to the series structure plate, and at least a portion of the second connecting plate is disposed in the second mounting groove along the thickness direction of the second connecting plate.

[0013] In some embodiments of the present invention, the sealing ring includes a first sealing ring and a second sealing ring arranged in the axial direction of the mounting hole.

[0014] In some embodiments of the present invention, a sealing ring is provided between the outer peripheral wall of the tandem structure plate and the inner peripheral wall of the housing.

[0015] In some embodiments of the present invention, the outer peripheral wall of the series structure is provided with an annular sealing groove extending along the circumferential direction of the series structure plate, and the inner peripheral wall of the housing is provided with an inwardly protruding annular protrusion, the annular protrusion extending into the annular sealing groove, and the sealing ring being located between the annular protrusion and the inner wall of the annular sealing groove.

[0016] In some embodiments of the present invention, an annular sealing groove extending along the circumferential direction of the series structure plate is provided on the outer peripheral wall of the series structure plate, the sealing ring is located in the annular sealing groove, and the sealing ring abuts against the inner peripheral wall of the housing.

[0017] In some embodiments of the present invention, the series structure plate is welded to the shell, or the outer peripheral wall of the series structure plate and the inner wall of the shell are sealed together by sealant.

[0018] In some embodiments of the present invention, the first electrode tab is an aluminum part, the first connecting plate is an aluminum part, the second electrode tab is a copper part, and the second connecting plate is a copper part.

[0019] In some embodiments of the present invention, the first direction is the length direction of the housing; and / or, the first direction is the length direction of the pole group.

[0020] The battery pack according to an embodiment of the present invention includes the battery cells described above.

[0021] According to an embodiment of the present invention, the battery pack, by setting the aforementioned battery cells, arranges multiple electrode groups spaced apart along a first direction within a housing. Any two adjacent electrode groups are respectively a first electrode group and a second electrode group. The ends of the first and second electrode groups closest to each other respectively have a first tab and a second tab. A series connection structure is provided between any two adjacent electrode groups, and both the first tab and the second tab are connected to the series connection structure to connect the adjacent electrode groups in series. This improves the energy density of the battery cells, saves space in the battery pack, results in a high energy density for the battery pack, and also ensures high internal electrochemical consistency of the battery cells, making it safer and more reliable.

[0022] Additional aspects and advantages of the invention 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 invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0024] Figure 1 This is a perspective view of a battery cell according to an embodiment of the present invention;

[0025] Figure 2 This is an exploded view of a battery cell according to an embodiment of the present invention, wherein the casing is not shown;

[0026] Figure 3 This is a perspective view of the series structure of a battery cell according to an embodiment of the present invention;

[0027] Figure 4 This is an exploded view of the series structure of a battery cell according to an embodiment of the present invention;

[0028] Figure 5 This is a cross-sectional view of a battery cell according to an embodiment of the present invention, wherein the view shows the state of the casing before it is rolled, and no annular protrusion is formed;

[0029] Figure 6 yes Figure 5 Enlarged view of point A in the middle;

[0030] Figure 7 This is a cross-sectional view of a battery cell according to an embodiment of the present invention, wherein the view shows the state in which an annular protrusion is formed after the casing is rolled;

[0031] Figure 8 yes Figure 7 Enlarged view of point B in the middle;

[0032] Figure 9 yes Figure 6 Enlarged view of point C in the middle.

[0033] Figure label:

[0034] 10. Battery cells;

[0035] 1. Shell; 11. Cylinder; 12. Cover plate; 13. Explosion-proof valve; 14. Annular protrusion;

[0036] 2. Pole group; 21. First pole group; 211. First pole tab; 22. Second pole group; 221. Second pole tab;

[0037] 3. Series structure; 31. First connecting plate; 32. Second connecting plate; 33. Pole post; 34. Series structure plate; 341. First groove; 342. Second groove; 343. Mounting hole; 35. Annular sealing groove; 36. First through hole;

[0038] 4. Insulating seal; 41. Sealing ring; 411. First sealing ring; 4111. First section; 4112. Second section; 412. Second sealing ring; 4121. Third section; 4122. Fourth section; 42. First insulating component; 421. First mounting groove; 43. Second insulating component; 431. Second mounting groove; 44. Second through hole;

[0039] 5. Sealing ring. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] The following is for reference. Figures 1-9 A battery cell 10 according to an embodiment of the present invention is described.

[0044] like Figure 1 and Figure 2 As shown, the battery cell 10 according to an embodiment of the present invention includes a housing 1, an electrode group 2, and a series structure 3.

[0045] Specifically, refer to Figure 1 and Figure 2 The electrode group 2 is located inside the housing 1, and the electrode group 2 is along the first direction (e.g., Figure 1Multiple pole groups 2 are spaced apart in the m direction shown. One of any two adjacent pole groups 2 is a first pole group 21 and the other is a second pole group 22. The first pole group 21 has a first pole tab 211 at the end near the second pole group 22, and the second pole group 22 has a second pole tab 221 at the end near the first pole group 21. A series structure 3 is provided between any two adjacent pole groups 2. The first pole tab 211 and the second pole tab 221 are connected to the series structure 3 so that the two adjacent pole groups 2 are connected in series.

[0046] It is understandable that the series structure 3 can conduct electricity, and multiple electrode groups 2 are connected in series through the series structure 3. After the multiple electrode groups 2 are connected in series, they are clamped by a fixing fixture and installed into the housing 1 to form a battery cell 10, thereby improving the energy density of the battery cell 10.

[0047] Meanwhile, since multiple electrode groups 2 are connected in series and then encapsulated in a housing 1 to form a single battery cell 10, compared to first encapsulating multiple electrode groups separately in multiple housings to form multiple battery cells and then connecting them in series, there is no need to reserve assembly and electrical connection gaps in the battery pack, which saves more space in the battery pack and thus results in a higher energy density. In addition, multiple electrode groups 2 are connected in series in the first direction to form a single battery cell 10, which, compared to forming a single battery cell through a single electrode group that is longer along the first direction, results in higher internal electrochemical consistency and greater safety and reliability.

[0048] Furthermore, taking three adjacent pole groups 2 as an example, the three pole groups 2 are arranged and connected in the first direction, and in the first direction, they are sequentially the front pole group, the middle pole group, and the rear pole group. When the front pole group and the middle pole group are two adjacent pole groups 2, the front pole group is the first pole group 21, and the middle pole group is the second pole group 22. When the middle pole group and the rear pole group are two adjacent pole groups 2, the middle pole group is the first pole group 21, and the rear pole group is the second pole group 22. Thus, each pole group 2 can be both the first pole group 21 and the second pole group 22.

[0049] Furthermore, the housing 1 includes a cylindrical body 11 and a cover plate 12. The cylindrical body 11 extends along a first direction, and there are two cover plates 12, which are located at both ends of the cylindrical body 11 along the first direction and are connected to the cylindrical body 11 to seal the two ends of the cylindrical body 11 along the first direction. At the same time, the cover plate 12 has a pole post 33, which is connected to the pole lug of the adjacent pole group 2. The pole post 33 and the cover plate 12 are insulated and sealed, so that the housing 1 forms a closed structure to protect and fix the pole group 2 inside the housing 1. The housing 1 is provided with multiple explosion-proof valves 13. When the battery experiences thermal runaway, the gas inside the pole group 2 can flow out from the explosion-proof valves 13 to prevent the battery cell 10 from exploding.

[0050] Among them, the pole post 33 and the tab are laser or ultrasonic welded, the cover plate 12 and the cylinder 11 are laser or ultrasonic welded, the cylinder 11 can be integrally extruded or spliced ​​and welded, the battery cell 10 can be various types of battery cells, such as lithium-ion battery cells or sodium-ion battery cells, and the shell 1 can be made of aluminum or steel structure, etc., with high structural strength, which makes the battery cell 10 have high structural strength.

[0051] exist Figure 1 and Figure 2 In the example shown, there are four explosion-proof valves 13, but the invention is not limited to this; there can be more or fewer explosion-proof valves 13, such as three, five, six, or seven, etc. Figure 1 and Figure 2 In the example shown, there are two pole groups 2, but the present invention is not limited to this. There can be more pole groups 2, such as 3, 5, 6 or 10.

[0052] According to an embodiment of the present invention, the battery cell 10 comprises a plurality of electrode groups 2 spaced apart along a first direction within a housing 1. Any two adjacent electrode groups 2 are respectively a first electrode group 21 and a second electrode group 22. The ends of the first electrode group 21 and the second electrode group 22 closest to each other have a first tab 211 and a second tab 221, respectively. A series structure 3 is provided between any two adjacent electrode groups 2, and the first tab 211 and the second tab 221 are connected to the series structure 3 to connect the adjacent electrode groups 2 in series. This improves the energy density of the battery cell 10, saves space in the battery pack, results in a high energy density in the battery pack, and also ensures high internal electrochemical consistency within the battery cell 10, making it safer and more reliable.

[0053] In some embodiments of the present invention, such as Figures 3-8 As shown, the series structure 3 includes a first connecting plate 31 and a second connecting plate 32. The first connecting plate 31 is connected to the first electrode 211, the second connecting plate 32 is connected to the second electrode 221, and the second connecting plate 32 is connected to the first connecting plate 31. Both the first connecting plate 31 and the second connecting plate 32 are conductive components.

[0054] It is understood that the second tab 221 and the first tab 211 are connected via the first connecting plate 31 and the second connecting plate 32, thereby realizing the series connection of the first electrode group 21 and the second electrode group 22. In this invention, the first connecting plate 31 and the first tab 211 are ultrasonically or laser welded, and the second connecting plate 32 and the second tab 221 are ultrasonically or laser welded, thereby ensuring a reliable connection between the first connecting plate 31 and the first tab 211, and a reliable connection between the second connecting plate 32 and the second tab 221, thus ensuring a reliable series connection between the first electrode group 21 and the second electrode group 22, and improving the working efficiency of the battery cell 10. The first connecting plate 31 and the first tab 211, as well as the second connecting plate 32 and the second tab 221, can also be connected by other means, such as fastener connection.

[0055] In some embodiments of the present invention, such as Figures 5-8 As shown, the first connecting plate 31 and the second connecting plate 32 are spaced apart. The series structure 3 also includes a pole post 33, which is located between the first connecting plate 31 and the second connecting plate 32. The two ends of the pole post 33 are respectively connected to the first connecting plate 31 and the second connecting plate 32.

[0056] It is understood that both the first connecting plate 31 and the second connecting plate 32 are provided with a first through hole 36 for the pole post 33 to pass through. The pole post 33 extends in the first direction, so that the pole post 33 can be inserted into the first connecting plate 31 and the second connecting plate 32. The two ends of the pole post 33 are respectively welded to the first connecting plate 31 and the second connecting plate 32. At the same time, the pole post 33 is a conductive component, so that the first connecting plate 31 and the second connecting plate 32 can be electrically connected, thereby facilitating the series connection between the first pole group 21 and the second pole group 22.

[0057] In some embodiments of the present invention, such as Figures 3-8 As shown, the series structure 3 also includes a series structure plate 34, which is fixed to the housing 1. The series structure plate 34 has mounting holes 343, and the pole post 33 passes through the mounting holes 343. The first connecting plate 31 and the second connecting plate 32 are located on both sides of the series structure plate 34, respectively.

[0058] Understandably, the series structure plate 34 increases the strength of the series structure 3, supporting the installation and stress of structures such as the first connecting plate 31 and the second connecting plate 32, preventing the series structure 3 from being squeezed and deformed, and improving its service life. The axes of the mounting hole 343 and the first through hole 36 coincide, allowing the pole post 33 to pass through both the mounting hole 343 and the first through hole 36 simultaneously. This prevents the first connecting plate 31 and the second connecting plate 32 from moving radially relative to the series structure plate 34 toward the mounting hole 343, improving the installation reliability of the first connecting plate 31 and the second connecting plate 32 with the series structure plate 34.

[0059] Furthermore, such as Figures 3-8 As shown, the peripheral wall of the series structure plate 34 is connected to the inner wall of the housing 1, so that the series structure 3 can be fixed on the housing 1. At the same time, since the series structure plate 34 is located between the first connecting plate 31 and the second connecting plate 32, it blocks the flow of electrolyte between the first electrode group 21 and the second electrode group 22, thereby improving the safety of the battery cell 10.

[0060] When assembling the series structure 3, the pole post 33 is first inserted into the first connecting plate 31, the series structure plate 34 and the second connecting plate 32 in sequence, and then the two ends of the pole post 33 are welded and fixed to the first connecting plate 31 and the second connecting plate 32 respectively.

[0061] In some embodiments of the present invention, such as Figures 3-8 As shown, the series structure plate 34 is a metal part, and an insulating seal 4 is provided between the series structure plate 34 and the pole post 33, between the series structure plate 34 and the first connecting plate 31, and between the series structure plate 34 and the second connecting plate 32.

[0062] Understandably, the series structure plate 34 is made of metal, such as aluminum or steel, which further increases the strength of the series structure plate 34, thereby increasing the strength of the series structure 3, further supporting the installation and stress of the first connecting plate 31 and the second connecting plate 32, while preventing the series structure 3 from being squeezed and deformed, and improving its service life.

[0063] Since the series structure plate 34 is a metal part and has conductivity, and the series structure plate 34 is connected to the housing 1, an insulating seal 4 is provided between the series structure plate 34 and the pole post 33, between the series structure plate 34 and the first connecting plate 31, and between the series structure plate 34 and the second connecting plate 32. This can insulate the series structure plate 34 and the pole post 33, between the series structure plate 34 and the first connecting plate 31, and between the series structure plate 34 and the second connecting plate 32, preventing current from flowing through the series structure plate 34 to the housing 1, thereby preventing leakage and improving safety.

[0064] In some embodiments of the present invention, such as Figures 3-8 As shown, the insulating seal 4 includes a sealing ring 41, a first insulating element 42, and a second insulating element 43. The sealing ring 41 is disposed between the outer peripheral wall of the electrode post 33 and the inner peripheral wall of the mounting hole 343. Thus, the sealing ring 41 can insulate the electrode post 33 from the series structure plate 34, thereby preventing leakage. At the same time, the sealing ring 41 can also prevent the electrolyte between the first electrode group 21 and the second electrode group 22 from flowing through the gap between the outer peripheral wall of the electrode post 33 and the inner peripheral wall of the mounting hole 343, thereby improving safety.

[0065] Furthermore, such as Figures 3-8As shown, the first insulating member 42 is at least partially disposed between the first connecting plate 31 and the series structure plate 34, and the second insulating member 43 is at least partially disposed between the second connecting plate 32 and the series structure plate 34. The edges of the first insulating member 42 and the second insulating member 43 extend to the edge of the series structure plate 34. Thus, the first insulating member 42 can insulate the first connecting plate 31 and the series structure plate 34, and the second insulating member 43 can insulate the second connecting plate 32 and the series structure plate 34, thereby preventing leakage and improving safety.

[0066] Among them, the insulating seal 4 is made of fluororubber resistant to electrolyte, which can avoid electrolyte corrosion and improve service life.

[0067] In some embodiments of the present invention, such as Figure 3 and Figure 4 As shown, the first insulating member 42 has a first mounting groove 421 on the side facing away from the series structure plate 34, and at least a portion of the first connecting plate 31 is disposed in the first mounting groove 421 along the thickness direction of the first connecting plate 31. The second insulating member 43 has a second mounting groove 431 on the side facing away from the series structure plate 34, and at least a portion of the second connecting plate 32 is disposed in the second mounting groove 431 along the thickness direction of the second connecting plate 32.

[0068] Understandably, the first mounting groove 421 and the second mounting groove 431 are recessed towards the series structure plate 34. At least a portion of the first connecting plate 31 is disposed within the first mounting groove 421 along the thickness direction of the first connecting plate 31, thereby allowing the first connecting plate 31 to be fixed within the first mounting groove 421, improving the installation reliability of the first connecting plate 31 and the first insulating member 42. Similarly, at least a portion of the second connecting plate 32 is disposed within the second mounting groove 431 along the thickness direction of the second connecting plate 32, thereby allowing the second connecting plate 32 to be fixed within the second mounting groove 431, improving the installation reliability of the second connecting plate 32 and the second insulating member 43.

[0069] Meanwhile, along the thickness direction of the first connecting plate 31, at least a portion of the first connecting plate 31 is disposed in the first mounting groove 421, and along the thickness direction of the second connecting plate 32, at least a portion of the second connecting plate 32 is disposed in the second mounting groove 431, which can save connection space and further improve the energy density of the battery cell 10.

[0070] In addition, the bottom wall of the first mounting groove 421 is provided with a second through hole 44 penetrating the first mounting groove 421, and the bottom wall of the second mounting groove 431 is also provided with a second through hole 44 penetrating the second mounting groove 431. The axes of the second through hole 44 and the first through hole 36 coincide, so that the pole post 33 can be inserted into the first insulating member 42 and the second insulating member 43, so that the first insulating member 42 and the second insulating member 43 can be fixed relative to the series structure plate 34.

[0071] In some embodiments of the present invention, such as Figures 5-9 As shown, the sealing ring 41 includes a first sealing ring 411 and a second sealing ring 412 arranged in the axial direction of the mounting hole 343.

[0072] Understandably, the first sealing ring 411 is positioned close to the first connecting plate 31 relative to the second sealing ring 412. The first sealing ring 411 includes a first segment 4111 and a second segment 4112 arranged and connected in the axial direction of the mounting hole 343. The first segment 4111 is positioned close to the first connecting plate 31 relative to the second segment 4112. The first segment 4111 and the second segment 4112 are coaxial, and the diameter of the first segment 4111 is larger than the diameter of the second segment 4112. The second sealing ring 412 includes a third segment 4121 and a fourth segment 4122 arranged and connected in the axial direction of the mounting hole 343. The third segment 4121 is positioned close to the first connecting plate 31 relative to the fourth segment 4122. The third segment 4121 and the fourth segment 4122 are coaxial, and the diameter of the third segment 4121 is smaller than the diameter of the fourth segment 4122.

[0073] Furthermore, such as Figures 5-9 As shown, a first groove 341 and a second groove 342 are respectively provided on both sides of the series structure plate 34 in the thickness direction. The first groove 341 is located closer to the first connecting plate 31 than the second groove 342. The mounting hole 343 penetrates the bottom wall of the first groove 341 and the second groove 342. The first groove 341, the second groove 342 and the mounting hole 343 are coaxial, and the diameters of the first groove 341 and the second groove 342 are both larger than the diameter of the mounting hole 343.

[0074] The first segment 4111 is located in the first groove 341, the fourth segment 4122 is located in the second groove 342, and the third segment 4121 and the second segment 4112 are located in the mounting hole 343 between the first groove 341 and the second groove 342. Since the diameter of the first segment 4111 is larger than the diameter of the second segment 4112, and the diameter of the first groove 341 is larger than the diameter of the mounting hole 343, the first sealing ring 411 can be fixed in the first groove 341, preventing it from entering the second groove 342. Similarly, since the diameter of the third segment 4121 is smaller than the diameter of the fourth segment 4122, and the diameter of the second groove 342 is larger than the diameter of the mounting hole 343, the second sealing ring 412 can be fixed in the second groove 342, preventing it from entering the first groove 341. This ensures reliable installation of both the first and second sealing rings and improves sealing performance.

[0075] In some embodiments of the present invention, such as Figures 3-8As shown, a sealing ring 5 is provided between the outer peripheral wall of the series structure plate 34 and the inner peripheral wall of the housing 1. Therefore, the sealing ring 5 can fill the gap between the outer peripheral wall of the series structure plate 34 and the inner peripheral wall of the housing 1, thereby further preventing electrolyte flow between the first electrode group 21 and the second electrode group 22, and further improving safety.

[0076] In some embodiments of the present invention, such as Figures 3-8 As shown, the outer peripheral wall of the series structure 3 is provided with an annular sealing groove 35 extending in the circumferential direction along the series structure plate 34, and the inner peripheral wall of the housing 1 is provided with an inwardly protruding annular protrusion 14. The annular protrusion 14 extends into the annular sealing groove 35, and the sealing ring 5 is located between the annular protrusion 14 and the inner wall of the annular sealing groove 35.

[0077] It is understandable that the annular protrusion 14 on the inner peripheral wall of the housing 1 is formed by rolling around the series structure 3 in the middle of the housing 1 with rollers, such as Figure 5 and Figure 6 As shown, the inner peripheral wall of the housing 1 does not have annular protrusions 14, such as Figure 7 and Figure 8 As shown, after the rollers roll around the series structure 3 in the middle of the housing 1, an inwardly protruding annular protrusion 14 is formed on the inner peripheral wall of the housing 1. The sealing ring 5 is located between the annular protrusion 14 and the inner wall of the annular sealing groove 35. After being rolled, the sealing ring 5 fits more tightly with the inner wall of the annular protrusion 14 and the annular sealing groove 35, thereby further preventing the electrolyte flow between the first electrode group 21 and the second electrode group 22, and further improving safety.

[0078] Among them, such as Figure 4 As shown, the size and compression of the sealing ring 5 can be adjusted according to the battery size. The width H1 of the sealing ring 5 in its radial direction is 1-10mm, such as 1mm, 3mm, 5mm or 10mm, etc. The thickness H2 of the sealing ring 5 in its axial direction is 1-10mm, such as 1mm, 3mm, 5mm or 10mm, etc. At the same time, the compression of the sealing ring 41 is 10%-80%, such as 10%, 20%, 40% or 80%, etc.

[0079] When assembling the series structure 3, firstly, install the first sealing ring 411 and the second sealing ring 412 into the mounting hole 343. Then, place the first insulating component 42 and the second insulating component 43 at both ends of the series structure plate 34 in the thickness direction. Next, place the first connecting plate 31 in the first mounting groove 421 of the first insulating component 42 and place the second connecting plate 32 in the second mounting groove 431 of the second insulating component 43. Then, sequentially pass the pole post 33 through the first connecting plate 31, the first insulating component 42, the series structure plate 34, the second insulating component 43, and the second connecting plate 32. Then, weld the two ends of the pole post 33 to the first connecting plate 31 and the second connecting plate 32 respectively. Finally, install the sealing ring 5 into the annular sealing groove 35 to complete the assembly of the series structure 3.

[0080] When assembling the battery cell 10, the first tab 211 of the first electrode group 21 of all two adjacent electrode groups 2 is welded to the first connecting plate 31, and the second tab 221 of the second electrode group 22 is welded to the second connecting plate 32. Then, the multiple electrode groups 2 connected in series are clamped by a fixing fixture and installed into the housing 1. At this time, rollers are used to roll around the series structure 3 in the middle of the housing 1. Then, a sealing test is performed by helium detection or air pressure method to ensure that there is no airtight conduction problem between the first electrode group 21 and the second electrode group 22. Then, the cover plate 12 and the cylinder 11 are welded together, and a sealing test is performed by helium detection or air pressure method to ensure that there is no airtight problem between the inside and outside of the housing 1. Finally, liquid injection, pre-charging and capacity grading charging are performed to complete the assembly of the battery cell 10.

[0081] In some embodiments of the present invention, an annular sealing groove 35 extending along the circumferential direction of the series structure plate 34 is provided on the outer peripheral wall of the series structure plate 34, the sealing ring 5 is located in the annular sealing groove 35, and the sealing ring 5 abuts against the inner peripheral wall of the housing 1.

[0082] Understandably, the annular sealing groove 35 is used to fix and install the sealing ring 5. The sealing ring 5 and the housing 1 are interference-fitted, which makes the sealing ring 5 and the inner peripheral wall of the housing 1 more reliable, thereby further preventing the electrolyte flow between the first electrode group 21 and the second electrode group 22, and further improving safety.

[0083] When assembling the series structure 3, firstly, install the first sealing ring 411 and the second sealing ring 412 into the mounting hole 343. Then, place the first insulating component 42 and the second insulating component 43 at both ends of the series structure plate 34 in the thickness direction. Next, place the first connecting plate 31 in the first mounting groove 421 of the first insulating component 42 and place the second connecting plate 32 in the second mounting groove 431 of the second insulating component 43. Then, sequentially pass the pole post 33 through the first connecting plate 31, the first insulating component 42, the series structure plate 34, the second insulating component 43, and the second connecting plate 32. Then, weld the two ends of the pole post 33 to the first connecting plate 31 and the second connecting plate 32 respectively. Finally, install the sealing ring 5 into the annular sealing groove 35 to complete the assembly of the series structure 3.

[0084] When assembling the battery cell 10, the first tab 211 of the first electrode group 21 of all two adjacent electrode groups 2 is welded to the first connecting plate 31, and the second tab 221 of the second electrode group 22 is welded to the second connecting plate 32. Then, the multiple electrode groups 2 connected in series are clamped into the housing 1 using a fixing fixture. Then, a sealing test is performed by helium detection or gas pressure method to ensure that there is no airtight conduction problem between the first electrode group 21 and the second electrode group 22. Then, the cover plate 12 and the cylinder 11 are welded together, and a sealing test is performed by helium detection or gas pressure method to ensure that there is no airtight problem between the inside and outside of the housing 1. Finally, liquid injection, pre-charging and capacity grading charging are performed to complete the assembly of the battery cell 10.

[0085] This reduces the number of steps required when assembling the battery cell 10, eliminates the need for rolling the casing 1, simplifies the operation, and improves production efficiency.

[0086] In some embodiments of the present invention, the series structure plate 34 is welded to the housing 1, or the outer peripheral wall of the series structure plate 34 and the inner wall of the housing 1 are sealed together with sealant. It is understood that welding the series structure plate 34 to the housing 1 or sealing the outer peripheral wall of the series structure plate 34 with the inner wall of the housing 1 with sealant can eliminate the gap between the outer peripheral wall of the series structure plate 34 and the inner peripheral wall of the housing 1, thereby preventing electrolyte flow between the first electrode group 21 and the second electrode group 22 and improving safety.

[0087] Meanwhile, when the series structure plate 34 is welded to the shell 1 or the outer peripheral wall of the series structure plate 34 and the inner wall of the shell 1 are sealed together with sealant, the sealing ring 5 can be omitted, thereby reducing the number of parts in the series structure 3 and simplifying the structure of the series structure 3.

[0088] In some embodiments of the present invention, the first tab 211 is made of aluminum, the first connecting plate 31 is made of aluminum, the second tab 221 is made of copper, and the second connecting plate 32 is made of copper. It is understood that having the first tab 211 and the first connecting plate 31 made of the same material, and the second tab 221 and the second connecting plate 32 made of the same material, can prevent electrochemical corrosion and improve lifespan.

[0089] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the first direction is the length direction of the casing 1, and the second direction is the length direction of the electrode group 2. This allows the electrode group 2 to be arranged in series along the length direction, thereby increasing the length of the battery cell 10, which in turn increases the energy density of the battery cell 10 in the length direction. It also saves space in the battery pack in the length direction, increases the energy density of the battery pack in the length direction, and makes the internal electrochemical consistency of the battery cell 10 high in the length direction.

[0090] The following describes a battery pack according to an embodiment of the present invention.

[0091] The battery pack according to an embodiment of the present invention includes the battery cell 10 described above.

[0092] According to an embodiment of the present invention, the battery pack, by setting the aforementioned battery cells 10, arranges a plurality of electrode groups 2 spaced apart along a first direction within the housing 1. Any two adjacent electrode groups 2 are respectively a first electrode group 21 and a second electrode group 22. The ends of the first electrode group 21 and the second electrode group 22 closest to each other have a first tab 211 and a second tab 221, respectively. A series structure 3 is provided between any two adjacent electrode groups 2, and the first tab 211 and the second tab 221 are connected to the series structure 3 to connect the adjacent two electrode groups 2 in series. This improves the energy density of the battery cells 10, saves space in the battery pack, results in high energy density of the battery pack, and also ensures high internal electrochemical consistency of the battery cells 10, making it safer and more reliable.

[0093] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, include: case; The electrode group is disposed inside the housing. The electrode group consists of a plurality of electrodes spaced apart along a first direction. One of any two adjacent electrode groups is a first electrode group and the other is a second electrode group. The first electrode group has a first electrode tab at the end near the second electrode group, and the second electrode group has a second electrode tab at the end near the first electrode group. A series structure is provided between any two adjacent pole groups, and the first and second pole tabs are both connected to the series structure to connect the two adjacent pole groups in series. The series structure includes: A first connecting plate, which is connected to the first electrode tab; The second connecting plate is connected to the second electrode tab and is connected to the first connecting plate. Both the first connecting plate and the second connecting plate are conductive components and are spaced apart. A pole post is disposed between the first connecting plate and the second connecting plate, and both ends of the pole post are respectively connected to the first connecting plate and the second connecting plate; A series structural plate is fixed to the housing. The series structural plate has mounting holes, and the pole piece passes through these holes. A first connecting plate and a second connecting plate are located on opposite sides of the series structural plate. A sealing ring is provided between the outer peripheral wall of the series structural plate and the inner peripheral wall of the housing. An annular sealing groove extending circumferentially from the outer peripheral wall of the series structural plate is provided, and the sealing ring is located within the annular sealing groove and abuts against the inner peripheral wall of the housing. The series structural plate is made of metal. Insulating seals are provided between the series structural plate and the pole piece, between the series structural plate and the first connecting plate, and between the series structural plate and the second connecting plate. The insulating seal includes: A sealing ring is disposed between the outer peripheral wall of the pole post and the inner peripheral wall of the mounting hole; A first insulating element is at least partially disposed between the first connecting plate and the series structure plate; A second insulating element is at least partially disposed between the second connecting plate and the series structure plate; The first insulating member has a first mounting groove on the side opposite to the series structure plate, and at least a portion of the first connecting plate is disposed in the first mounting groove along the thickness direction of the first connecting plate. Alternatively, the second insulating member has a second mounting groove on the side opposite to the series structure plate, and at least a portion of the second connecting plate is disposed in the second mounting groove along the thickness direction of the second connecting plate. The outer peripheral wall of the series structure plate has an annular sealing groove extending in the circumferential direction of the series structure plate. The inner peripheral wall of the housing has an inwardly protruding annular protrusion extending into the annular sealing groove. The sealing ring is located between the annular protrusion and the inner wall of the annular sealing groove.

2. The battery cell according to claim 1, characterized in that, The sealing rings include a first sealing ring and a second sealing ring arranged in the axial direction of the mounting hole.

3. The battery cell according to claim 1, characterized in that, The series structural plate is welded to the shell, or the outer peripheral wall of the series structural plate and the inner wall of the shell are sealed together by sealant.

4. The battery cell according to claim 1, characterized in that, The first electrode tab is made of aluminum, the first connecting plate is made of aluminum, the second electrode tab is made of copper, and the second connecting plate is made of copper.

5. The battery cell according to claim 1, characterized in that, The first direction is the length direction of the shell; And / or, the first direction is the length direction of the pole group.

6. A battery pack, characterized in that, Includes the battery cell according to any one of claims 1-5.

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