Battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery pack. The battery cell comprises: a housing, which is provided with a cavity and an opening communicated with the cavity; the cover plate is arranged on the opening and seals the cavity, and a through hole is formed in the cover plate; the pole comprises a main body part and an annular part located on one side of the main body part, the annular part penetrates through the through hole, and a groove is formed in the end, away from the main body part, of the annular part; and the connecting sheet is arranged in the cavity and is provided with a bulge matched with the groove, and the connecting sheet and the pole are fixedly connected by inserting the bulge into the groove. The groove is formed in one end, far away from the main body part, of the annular part, so that the self weight of the pole can be reduced while smooth circulation of current between the pole and the connecting piece is ensured. And moreover, the bulges matched with the grooves are arranged on the connecting sheets, so that not only can the assembly efficiency between the pole columns and the connecting sheets be improved, but also the contact area between the connecting sheets and the pole columns can be increased, and the overcurrent capability of the battery cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery cell and a battery pack. Background Art

[0002] In order to effectively guide current into or out of the battery cell, a pole column is usually arranged on the battery cell cover plate as a current diversion channel.

[0003] However, most of the pole columns currently used on the battery cell cover plate are cylindrical, and this shape will increase the weight of the battery cell to a certain extent, so it does not meet the current lightweight requirements of the battery cell. Summary of the Utility Model

[0004] In view of this, the utility model provides a battery cell and a battery pack to solve the problem that the relatively large self-weight of the pole column in the related art affects the lightweight of the battery cell.

[0005] In a first aspect, the utility model provides a battery cell, comprising:

[0006] A housing, provided with a cavity and an opening communicating with the cavity;

[0007] A cover plate, arranged on the opening and sealing the cavity, and the cover plate is provided with a through hole;

[0008] A pole column, comprising a main body part and an annular part located on one side of the main body part, the annular part passes through the through hole, and a groove is formed at one end of the annular part away from the main body part;

[0009] A connecting piece, arranged in the cavity and provided with a protrusion matching with the groove, and the connecting piece and the pole column are fixedly connected by inserting the protrusion into the groove.

[0010] Advantages: By providing an opening on the housing that communicates with its cavity, it is convenient for operators to assemble related structures such as connecting pieces into the housing, improving the convenience of assembly. Further, using a cover plate to seal the opening ensures the tightness of the battery cell, reducing the possibility of external moisture, dust and other impurities entering the interior of the battery cell, ensuring the cleanliness and stability of the internal environment of the battery cell, and thus being conducive to extending the service life of the battery cell. Secondly, setting the main body of the terminal post outside the housing and connecting the annular portion of the terminal post to the connecting piece inside the housing is conducive to guiding the current to flow into or out of the battery cell. Moreover, forming a groove at one end of the annular portion away from the main body can, while ensuring the smooth flow of current between the terminal post and the connecting piece, reduce the self-weight of the terminal post, making the battery cell meet the requirements of lightweight. In addition, providing a protrusion on the connecting piece that cooperates with the groove can not only enable operators to accurately position the terminal post and the connecting piece in a short time, improving the assembly efficiency, but also increase the contact area between the connecting piece and the terminal post, improving the over-current capacity of the battery cell.

[0011] In an alternative embodiment, the annular portion extends along the axial direction of the main body portion, and the diameter of the annular portion is smaller than the diameter of the main body portion.

[0012] Advantages: In the present utility model, the annular portion extends along the axial direction of the main body portion. On the one hand, it can reduce the complexity of the production process of the terminal post and improve the production efficiency; on the other hand, it can also reduce the assembly difficulty between the terminal post and the cover plate and improve the assembly efficiency. Secondly, making the diameter of the annular portion smaller than the diameter of the main body portion can enable the annular portion to play a role of positioning and guiding during the assembly process, shortening the time consumed for installing and positioning the terminal post and the through hole. In addition, compared with the case where the diameter of the annular portion is adapted to the diameter of the main body portion, the diameter of the annular portion being smaller than the diameter of the main body portion reduces the usage amount of the terminal post material and optimizes the self-weight of the terminal post.

[0013] In an alternative embodiment, the annular portion is provided with an annular flange on the circumferential side of the notch of the groove, and the annular flange is connected to the connecting piece.

[0014] Advantages: In the present utility model, the main body portion and the annular flange at both ends of the annular portion can form a limiting structure of the terminal post through cooperation with the cover plate, avoiding the terminal post from deviating from the preset position during the assembly or use of the battery cell, and improving the use stability and safety of the battery cell. Secondly, by providing an annular flange at one end of the annular portion close to the connecting piece, the contact area between the terminal post and the connecting piece can be increased. In this way, not only can the connection stability between the two be improved, but also the over-current capacity of the battery cell can be improved.

[0015] In an alternative embodiment, it further includes a sealing ring, a plastic ring, and a plastic plate. The sealing ring is sleeved outside the annular portion and abuts against the pore wall of the through hole. The plastic ring is internally provided with a mounting hole adapted to the shapes of the main body portion and the annular portion. The pore wall at the upper end of the mounting hole abuts against the side wall of the main body portion, and the lower end of the mounting hole is located inside the through hole and abuts against the sealing ring. The plastic plate is sleeved outside the annular portion and is located between the sealing ring and the annular flange.

[0016] Beneficial effects: By providing the sealing ring, the plastic ring, and the plastic plate, the present utility model can seal the gap between the pole column and the through hole, preventing the electrolyte inside the battery cell from overflowing through the above-mentioned gap. Secondly, since the material of the cover plate is usually a metal conductive material, the use of the plastic ring can keep the cover plate and the pole column in an insulated and isolated state all the time. Similarly, by using the plastic plate, the cover plate and the connecting piece can be kept in an insulated and isolated state all the time, thus ensuring the safety of use of the battery cell. In addition, since part of the structures of the plastic ring and the plastic plate and the sealing ring are located between the main body portion and the annular flange, the sealing ring, the plastic ring, and the plastic plate can be firmly fixed on the cover plate through the limiting cooperation between the main body portion and the annular flange.

[0017] In an alternative embodiment, the battery cell further includes a pole group. The pole group is arranged inside the housing and is provided with pole tabs. The pole tabs are arranged in a staggered manner with respect to the corresponding pole columns and are connected to the pole columns through the connecting pieces. The cover plate is provided with welding through holes, and the positions of the welding through holes correspond to the positions of the pole tabs.

[0018] Beneficial effects: The pole columns and the pole tabs of the present utility model are arranged in a staggered manner, making use of the space in the length direction inside the housing. Compared with the existing situation where the connecting pieces and the pole tabs are both arranged along the axial direction of the pole columns, the internal space of the housing occupied by the connecting pieces and the pole tabs in the height direction of the housing in the connected state is reduced, improving the utilization rate of the internal space of the housing. Furthermore, more energy can be stored in the battery cell of the same volume. Secondly, by connecting the pole tabs to the pole columns through the connecting pieces, the current can be introduced into or led out of the battery cell. Moreover, by providing welding through holes corresponding to the positions of the pole tabs on the cover plate, a suitable operating space can be provided for the operator, so that the operator can complete the operation of welding the pole tabs and the connecting pieces.

[0019] In an alternative embodiment, the cover plate is provided with a sealing plate. The sealing plate seals the welding through holes, and the sealing plate is provided with a liquid injection hole and an explosion-proof valve.

[0020] Beneficial effects: By using a sealing plate to seal the welding through-holes on the cover plate, the present utility model can improve the sealing performance of the battery cell and reduce the possibility of external impurities entering the interior of the battery cell. Secondly, by arranging the liquid injection hole and the explosion-proof valve on the sealing plate, on the one hand, the self-structure of the cover plate can be made more compact, optimizing the structural layout on the cover plate; on the other hand, it is convenient to add electrolyte into the interior of the battery cell, and at the same time, it can prevent the pressure inside the battery cell from being too high, improving the safety of use of the battery cell.

[0021] In an alternative embodiment, the tab includes a body connected to the electrode group and a bent portion bent from an end of the body toward one side; the connecting piece is fixed in the space defined by the body and the bent portion and is attached to the lower surface of the bent portion.

[0022] Beneficial effects: The tab of the present utility model is connected to the connecting piece through the bent portion, which can not only reduce the operation difficulty of connecting the tab and the connecting piece, but also reduce the occupation of the internal space of the housing in the connected state, enabling the battery cell to store more energy under the same volume.

[0023] In an alternative embodiment, the connecting piece includes a pole connecting portion connected to the pole column and a tab connecting portion connected to the tab, and a transition connecting portion is formed between the tab connecting portion and the pole connecting portion.

[0024] Beneficial effects: Since the tab and the pole column of the present utility model are arranged in a staggered manner, the connecting piece is divided into a pole connecting portion and a tab connecting portion, which can adapt the position of the connecting piece to the tab and the pole column, so as to connect the tab and the pole column and realize the smooth flow of current between the tab and the pole column. In addition, by forming a transition connecting portion between the tab connecting portion and the pole connecting portion, the stress concentration phenomenon between the tab connecting portion and the pole connecting portion can be avoided, ensuring the connection strength between the two.

[0025] In an alternative embodiment, a cavity is provided inside the protrusion.

[0026] Beneficial effects: By setting the inside of the protrusion to be hollow in the present utility model, the material usage can be reduced. In this way, not only can the production cost be reduced, but also it is beneficial to reduce the weight of the battery cell, meeting the lightweight development requirements of the battery cell.

[0027] In a second aspect, the present utility model also provides a battery pack, including:

[0028] A plurality of the above-mentioned battery cells.

[0029] Beneficial effects: Since the above-mentioned battery cell adjusts the structure and shape of its own pole post in order to reduce its own weight, the weight of the battery pack prepared by the above-mentioned battery cell will also be correspondingly reduced, thereby meeting the development requirements of lightweight. In addition, the battery pack of the present invention has all the advantages of the above-mentioned battery cell, which will not be elaborated here. Description of the drawings

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 It is a schematic structural diagram of a battery cell according to an embodiment of the present invention;

[0032] Figure 2 It is a schematic structural diagram of a cover plate according to an embodiment of the present invention;

[0033] Figure 3 is Figure 2 a cross-sectional view of the shown cover plate;

[0034] Figure 4 is Figure 1 a cross-sectional view of the shown battery cell;

[0035] Figure 5 is Figure 4 a partial enlarged view of A in;

[0036] Figure 6 It is a schematic structural diagram of another battery cell according to an embodiment of the present invention;

[0037] Figure 7 is Figure 6 a schematic structural diagram when the housing and the cover plate are not installed;

[0038] Figure 8 It is a schematic structural diagram of still another battery cell according to an embodiment of the present invention;

[0039] Figure 9 It is a schematic structural diagram of a battery cell when the housing and the cover plate are not installed according to an embodiment of the present invention.

[0040] Explanation of the reference numerals:

[0041] 1. Housing; 101. Cavity; 2. Cover plate; 201. Welding through-hole; 202. Sealing plate; 3. Terminal; 301. Main body part; 302. Ring part; 303. Ring flange; 4. Connecting piece; 401. Protrusion; 4011. Cavity; 402. Terminal connecting part; 403. Tab connecting part; 404. Transition connecting part; 5. Sealing ring; 6. Plastic ring; 7. Plastic plate; 8. Electrode group; 801. Tab; 8011. Body; 8012. Bent part; 9. Liquid injection hole; 10. Explosion-proof valve. Detailed implementation manners

[0042] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0043] In view of the problem that the relatively large self-weight of the terminal in the related art affects the light weight of the battery cell, the present utility model provides a battery cell and a battery pack.

[0044] The following combines Figures 1 to 9 to describe the embodiments of the present utility model.

[0045] For the convenience of description, the height direction and the length direction of the housing 1 in this embodiment are described in the direction shown in Figure 1 the figure.

[0046] According to an embodiment of the present utility model, on the one hand, as shown in Figures 1 to 9 the figure, a battery cell is provided, including: a housing 1, a cover plate 2, a terminal 3 and a connecting piece 4.

[0047] Specifically, the housing 1 is provided with a cavity 101 and an opening communicating with the cavity 101; the cover plate 2 is arranged on the opening and seals the cavity 101, and the cover plate 2 is provided with a through-hole; the terminal 3 includes a main body part 301 and a ring part 302 located on one side of the main body part 301, the ring part 302 penetrates through the through-hole, and a groove is formed at one end of the ring part 302 away from the main body part 301; the connecting piece 4 is arranged in the cavity 101 and is provided with a protrusion 401 matching with the groove, and the connecting piece 4 and the terminal 3 are fixedly connected by inserting the protrusion 401 into the groove.

[0048] In this embodiment, an opening communicating with the cavity 101 is provided on the housing 1, facilitating the operator to assemble related structures such as the connecting piece 4 into the housing 1 and improving the assembly convenience. Further, the cover plate 2 is used to seal the opening, ensuring the tightness of the battery cell, reducing the possibility of external moisture, dust and other impurities entering the interior of the battery cell, guaranteeing the cleanliness and stability of the interior environment of the battery cell, and thus being beneficial to extending the service life of the battery cell. Secondly, the main body portion 301 of the pole column 3 is arranged outside the housing 1, and at the same time, the annular portion 302 of the pole column 3 is connected to the connecting piece 4 inside the housing 1, which is conducive to guiding the current to flow into or out of the battery cell. Moreover, a groove is formed at one end of the annular portion 302 far from the main body portion 301, which can reduce the self-weight of the pole column 3 while ensuring the smooth flow of current between the pole column 3 and the connecting piece 4, making the battery cell meet the requirement of light weight. In addition, a protrusion 401 matching the groove is provided on the connecting piece 4, which can not only enable the operator to accurately position the pole column 3 and the connecting piece 4 in a short time, improving the assembly efficiency, but also increase the contact area between the connecting piece 4 and the pole column 3, improving the over-current capacity of the battery cell.

[0049] It should be noted that the shape of the groove in this embodiment can be, but is not limited to, cylindrical and frustum-shaped. In addition, in order to improve the stability of the groove and the protrusion 401 in the connected state, the shape and size of the protrusion 401 can be adapted to the shape and size of the groove.

[0050] In order to further reduce the self-weight of the pole column 3, in a specific embodiment, the distance between the groove opening and the groove bottom of the groove is consistent with the length of the annular portion 302 in the height direction of the housing 1.

[0051] It should be added that since the pole columns 3 on the battery cell are divided into positive pole columns and negative pole columns, in order to reduce the weight of the battery cell, grooves can be formed on only one of the positive pole column and the negative pole column, or grooves can be formed on both the positive pole column and the negative pole column. It can be understood that since the pole columns 3 on the battery cell are divided into positive pole columns and negative pole columns, in order to avoid short circuit between the positive pole column and the negative pole column, a pair of spaced-apart connecting pieces 4 need to be provided inside the battery cell.

[0052] According to an embodiment of the present invention, as Figures 3 to 5As shown, the annular portion 302 extends along the axial direction of the main body portion 301, and the diameter of the annular portion 302 is smaller than that of the main body portion 301. In this embodiment, the annular portion 302 extends along the axial direction of the main body portion 301. On the one hand, it can reduce the complexity of the production process of the pole column 3 and improve the production efficiency; on the other hand, it can also reduce the assembly difficulty between the pole column 3 and the cover plate 2 and improve the assembly efficiency. Secondly, making the diameter of the annular portion 302 smaller than that of the main body portion 301 enables the annular portion 302 to play a role in positioning and guiding during the assembly process, shortening the time consumed for the pole column 3 to be installed and positioned with the through hole. In addition, compared with the case where the diameter of the annular portion 302 is adapted to that of the main body portion 301, the diameter of the annular portion 302 being smaller than that of the main body portion 301 reduces the usage amount of the material of the pole column 3 and optimizes the self-weight of the pole column 3.

[0053] According to an embodiment of the present invention, as Figures 3 to 5 shown, the annular portion 302 is provided with an annular flange 303 on the circumferential side of the notch of the groove, and the annular flange 303 is connected to the connecting piece 4. In this embodiment, the main body portion 301 and the annular flange 303 at both ends of the annular portion 302 can form a limiting structure of the pole column 3 through cooperation with the cover plate 2, avoiding the pole column 3 from deviating from the preset position during the assembly or use of the battery cell, and improving the use stability and safety of the battery cell. Secondly, by providing the annular flange 303 at one end of the annular portion 302 close to the connecting piece 4, the contact area between the pole column 3 and the connecting piece 4 can be increased. In this way, not only can the connection stability between the two be improved, but also the over-current capacity of the battery cell can be improved.

[0054] According to an embodiment of the present invention, as Figure 5As shown in the figure, the battery cell further includes a sealing ring 5, a plastic ring 6 and a plastic plate 7. The sealing ring 5 is sleeved outside the annular portion 302 and abuts against the pore wall of the through hole. The plastic ring 6 is internally provided with a mounting hole adapted to the shapes of the main body portion 301 and the annular portion 302. The pore wall at the upper end of the mounting hole abuts against the side wall of the main body portion 301, and the lower end of the mounting hole is located inside the through hole and abuts against the sealing ring 5. The plastic plate 7 is sleeved outside the annular portion 302 and is located between the sealing ring 5 and the annular flange 303. In this embodiment, by providing the sealing ring 5, the plastic ring 6 and the plastic plate 7, the gap between the pole column 3 and the through hole can be sealed to prevent the electrolyte inside the battery cell from overflowing from the above-mentioned gap. Secondly, since the material of the cover plate 2 is usually a metal conductive material, the use of the plastic ring 6 can keep the cover plate 2 and the pole column 3 in an insulated and isolated state all the time. Similarly, by using the plastic plate 7, the cover plate 2 and the connecting piece 4 can be kept in an insulated and isolated state all the time, thus ensuring the use safety of the battery cell. In addition, since part of the structures of the plastic ring 6 and the plastic plate 7 and the sealing ring 5 are located between the main body portion 301 and the annular flange 303, the sealing ring 5, the plastic ring 6 and the plastic plate 7 can be firmly fixed on the cover plate 2 through the limiting cooperation of the main body portion 301 and the annular flange 303.

[0055] It should be noted that the sealing ring 5, the plastic ring 6 and the plastic plate 7 in this embodiment are all made of insulating materials.

[0056] According to an embodiment of the present invention, as Figures 6 to 9 shown in the figure, the battery cell further includes a pole group 8. The pole group 8 is arranged in the housing 1 and is provided with pole tabs 801. The pole tabs 801 are arranged in a staggered manner with respect to the corresponding pole columns 3 and are connected to the pole columns 3 through connecting pieces 4. The cover plate 2 is provided with welding through holes 201, and the positions of the welding through holes 201 correspond to the positions of the pole tabs 801. In this embodiment, the pole columns 3 and the pole tabs 801 are arranged in a staggered manner, making use of the space in the length direction inside the housing 1. Compared with the existing situation where both the connecting piece 4 and the pole tab 801 are arranged along the axial direction of the pole column 3, the internal space of the housing 1 occupied by the connecting piece 4 and the pole tab 801 in the height direction of the housing 1 in the connected state is reduced, improving the utilization rate of the internal space of the housing 1. Furthermore, more energy can be stored in the battery cell with the same volume. Secondly, by connecting the pole tabs 801 and the pole columns 3 through the connecting pieces 4, the current can be introduced into or led out of the battery cell. Moreover, by providing the welding through holes 201 corresponding to the positions of the pole tabs 801 on the cover plate 2, a suitable operating space can be provided for the operator, so that the operator can complete the operation of welding the pole tabs 801 and the connecting pieces 4.

[0057] It should be noted that, in order to optimize the structural layout on the cover body, in a specific embodiment, the welding through-hole 201 is located between the positive electrode post and the negative electrode post on the cover plate 2. In addition, in order to reduce the complexity of the manufacturing process of the cover plate 2, only one welding through-hole 201 may be provided on the cover plate.

[0058] According to an embodiment of the present invention, as Figure 1 shown, a sealing plate 202 is provided on the cover plate 2. The sealing plate 202 seals the welding through-hole 201 and the injection hole 9 and the explosion-proof valve 10 are provided on the sealing plate 202. In this embodiment, by using the sealing plate 202 to seal the welding through-hole 201 on the cover plate 2, the sealing performance of the battery cell can be improved, and the possibility of external impurities entering the interior of the battery cell can be reduced. Secondly, by arranging the injection hole 9 and the explosion-proof valve 10 on the sealing plate 202, on the one hand, the self-structure of the cover plate 2 can be made more compact, optimizing the structural layout on the cover plate 2; on the other hand, it is convenient to add electrolyte into the interior of the battery cell, and at the same time, the pressure inside the battery cell can be prevented from being too high, improving the use safety of the battery cell.

[0059] According to an embodiment of the present invention, as Figure 9 shown, the tab 801 includes a body 8011 connected to the electrode group 8 and a bent portion 8012 bent from the end of the body 8011 toward one side; the connecting piece 4 is fixed in the space defined by the body 8011 and the bent portion 8012 and is attached to the lower surface of the bent portion 8012. In this embodiment, the tab 801 is connected to the connecting piece 4 through the bent portion 8012, which can not only reduce the operation difficulty of connecting the tab 801 and the connecting piece 4, but also reduce the occupation of the internal space of the housing 1 when they are in the connected state, enabling the battery cell to store more energy under the same volume.

[0060] According to an embodiment of the present invention, as Figure 7 and Figure 9 shown, the connecting piece 4 includes a pole connection portion 402 connected to the pole 3 and a tab connection portion 403 connected to the tab 801. A transition connection portion 404 is formed between the tab connection portion 403 and the pole connection portion 402. Since the tab 801 and the pole 3 are arranged in a staggered manner in this embodiment, the connecting piece 4 is divided into the pole connection portion 402 and the tab connection portion 403, which can make the position of the connecting piece 4 adapt to the positions of the tab 801 and the pole 3, so that the tab 801 and the pole 3 can be connected, realizing the smooth flow of current between the tab 801 and the pole 3. In addition, by forming the transition connection portion 404 between the tab connection portion 403 and the pole connection portion 402, the stress concentration phenomenon between the tab connection portion 403 and the pole connection portion 402 can be avoided, ensuring the connection strength between the two.

[0061] According to an embodiment of the present invention, as Figures 3 to 5As shown, a cavity 4011 is provided inside the protrusion 401. In this embodiment, the inside of the protrusion 401 is set to be hollow, which can reduce the amount of material used. In this way, not only can the production cost be reduced, but also it is beneficial to reduce the weight of the battery cell, meeting the requirements of the lightweight development of the battery cell.

[0062] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including: a plurality of the above-mentioned battery cells. Since the above-mentioned battery cells have adjusted the structure and shape of their own pole posts 3 in order to reduce their own weight, the weight of the battery pack prepared by the above-mentioned battery cells will also be correspondingly reduced, thus also meeting the requirements of lightweight development. In addition, the battery pack of the present invention has all the advantages of the above-mentioned battery cells and will not be elaborated here.

[0063] It should be noted that the battery cells in this embodiment can be, but are not limited to, lithium-ion batteries, lithium manganate batteries, and nickel cobalt manganese ternary material batteries. Specifically, taking the lithium-ion battery as an example, the battery pack in this embodiment can be formed by connecting a plurality of lithium-ion batteries in series, or by connecting a plurality of lithium-ion batteries in parallel, or by preparing a plurality of lithium-ion batteries in a series-parallel combination manner. Specifically, it can be adjusted according to the actual application scenario and requirements, and the present invention does not make specific limitations in this regard.

[0064] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, Comprising: A housing, provided with a cavity and an opening communicating with the cavity; A cover plate, arranged on the opening and sealing the cavity, and a through hole is provided on the cover plate; A pole column, comprising a main body portion and an annular portion located on one side of the main body portion, the annular portion penetrates through the through hole, and a groove is formed at one end of the annular portion away from the main body portion; A connecting piece, arranged in the cavity and provided with a protrusion matching with the groove, and the connecting piece and the pole column are fixedly connected by inserting the protrusion into the groove.

2. The battery cell according to claim 1, characterized in that, The annular portion extends along the axial direction of the main body portion, and the diameter of the annular portion is smaller than that of the main body portion.

3. The battery cell according to claim 2, wherein An annular flange is arranged on the circumferential side of the notch of the groove of the annular portion, and the annular flange is connected with the connecting piece.

4. The battery cell according to claim 3, characterized in that, Also included are a sealing ring, a plastic ring and a plastic plate. The sealing ring is sleeved outside the annular portion and abuts against the hole wall of the through hole. The plastic ring is internally provided with a mounting hole adapted to the shapes of the main body portion and the annular portion. The hole wall at the upper end of the mounting hole abuts against the side wall of the main body portion. The lower end of the mounting hole is located in the through hole and abuts against the sealing ring. The plastic plate is sleeved outside the annular portion and is located between the sealing ring and the annular flange.

5. The battery cell according to any one of claims 1 to 4, characterized in that Also included is an electrode group, which is arranged in the housing and is provided with electrode tabs. The electrode tabs are arranged in a staggered manner with the corresponding pole columns and are connected with the pole columns through the connecting pieces. A welding through hole is provided on the cover plate, and the position of the welding through hole corresponds to the position of the electrode tab.

6. The battery cell according to claim 5, characterized in that, A sealing plate is provided on the cover plate, the sealing plate seals the welding through hole, and a liquid injection hole and an explosion-proof valve are provided on the sealing plate.

7. The cell according to claim 5, wherein The electrode tab includes a main body connected with the electrode group and a bent portion bent from the end of the main body towards one side. The connecting piece is fixed in the space defined by the main body and the bent portion and is attached to the lower surface of the bent portion.

8. The battery cell according to claim 5, characterized in that, The connecting piece includes a pole column connecting portion connected with the pole column and an electrode tab connecting portion connected with the electrode tab, and a transition connecting portion is formed between the electrode tab connecting portion and the pole column connecting portion.

9. The battery cell according to any one of claims 1 to 4, characterized in that, A cavity is provided in the protrusion.

10. A battery pack, characterized in that, Comprising: Multiple battery cells according to any one of claims 1 to 9.

Images