Battery cell, battery pack and vehicle

Abstract

The invention discloses a battery cell, a battery pack and a vehicle, the battery cell comprises a shell, a roll core, a positive electrode assembly and a top cover assembly, the roll core is arranged in the shell, a center hole is formed in the roll core, the center hole penetrates through the roll core along the length direction of the shell, the positive electrode assembly is arranged in the shell, the positive electrode assembly comprises a positive electrode collector plate and a positive electrode guide column, and the top cover assembly is arranged on the roll core. The positive collector plate is connected with one end of the positive guide column, the positive collector plate is connected with the roll core, the positive guide column penetrates through the center hole, the top cover assembly is arranged on the positive guide column in a sleeving mode, and the top cover assembly and the positive collector plate are oppositely arranged in the length direction of the shell. According to the battery cell provided by the embodiment of the invention, the assembly precision between the shell and the top cover and between the roll core and the top cover can be improved, so that the yield of battery cell welding is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power batteries, and in particular relates to a battery cell, a battery pack and a vehicle. Background Art

[0002] The popularity of new energy vehicles is increasing. However, consumers always have mileage anxiety and charging anxiety about new energy vehicles. Therefore, in order to improve the energy density and fast charging capability of the battery, a cylindrical battery is disclosed in the related art. However, the cylindrical battery in the related art has poor matching accuracy between the shell and the top cover, and between the top cover and the winding core, resulting in a low yield in the welding process of the battery cell, which not only increases the manufacturing cost of the battery cell, but also affects the service life and safety of the battery cell. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, an embodiment of the present invention provides a battery cell that can improve the assembly accuracy between the shell and the top cover and between the winding core and the top cover, thereby improving the yield rate of battery cell welding.

[0004] An embodiment of the present invention further provides a battery pack.

[0005] An embodiment of the present invention also provides a vehicle.

[0006] The battery cell of the embodiment of the present invention comprises: a shell; a winding core, which is arranged in the shell and has a center hole, and the center hole passes through the winding core along the length direction of the shell; a positive electrode assembly, which is arranged in the shell, and the positive electrode assembly includes a positive current collecting disk and a positive electrode guide post, the positive current collecting disk is connected to one end of the positive electrode guide post, and the positive current collecting disk is connected to the winding core, and the positive electrode guide post passes through the center hole; a top cover assembly, which is sleeved on the positive electrode guide post, and the top cover assembly and the positive current collecting disk are arranged opposite to each other in the length direction of the shell.

[0007] In the battery cell of the embodiment of the present invention, the positive electrode guide post is arranged inside the winding core, which can support and position the winding core, thereby improving the fitting accuracy between the winding core and the positive electrode guide post and the installation accuracy of the winding core in the shell. The positive electrode guide post is connected to the top cover assembly. The guiding effect of the positive electrode guide post can improve the fitting accuracy between the positive electrode guide post and the top cover assembly, thereby improving the fitting accuracy between the winding core and the top cover assembly and between the top cover assembly and the shell, thereby improving the yield rate of battery cell welding.

[0008] In some embodiments, the winding core includes a winding core body and a positive electrode tab, the positive electrode tab is connected to the winding core body, and the positive electrode tab is connected to the positive current collecting disk, the positive electrode tab is an annular tab, the inner ring of the positive electrode tab has a diameter A, and 6mm≤A≤25mm.

[0009] In some embodiments, the battery cell also includes an insulating gasket, which is arranged between the positive current collector disk and the shell, and the positive current collector disk includes a positive disk body and a positive boss, the positive disk body is in contact with the positive pole ear, the positive boss protrudes in the length direction of the shell away from the winding core, the positive boss abuts against the insulating gasket, and / or a groove is opened on the positive disk body.

[0010] In some embodiments, a first step portion is provided on a side of the positive electrode guide column adjacent to the positive electrode disc, and the first step portion penetrates the positive electrode disc.

[0011] In some embodiments, the positive electrode guide column has a guide column hole therein, the guide column hole passes through the positive electrode guide column along the length direction of the shell, a first flow gap is provided between the positive electrode disk and the insulating gasket, and the guide column hole is connected to the first flow gap.

[0012] In some embodiments, the winding core also includes a negative electrode tab, which is connected to the winding core body, and the negative electrode tab and the positive electrode tab are arranged relative to each other in the length direction of the shell, and the negative electrode tab is an annular tab, the diameter of the inner ring of the negative electrode tab is B, and 10mm≤B≤25mm, and / or the diameter of the outer ring of the negative electrode tab is less than or equal to the diameter of the winding core body.

[0013] In some embodiments, the battery cell further includes a negative electrode assembly, the negative electrode assembly is connected to the negative electrode tab, and the negative electrode assembly is located between the negative electrode tab and the top cover assembly.

[0014] The negative electrode assembly includes a negative electrode collector disk and a thermally conductive gasket, wherein the thermally conductive gasket is arranged between the negative electrode collector disk and the top cover assembly, the negative electrode collector disk includes a negative electrode disk body and a negative electrode boss, the negative electrode disk body is in contact with the negative electrode ear, the negative electrode boss protrudes in the length direction of the shell along the direction away from the winding core, the negative electrode boss abuts against the thermally conductive gasket, and / or a groove is opened on the negative electrode disk body.

[0015] In some embodiments, the negative electrode current collector disk further includes a pin portion, which surrounds the negative electrode disk body and extends in a direction away from the winding core in the length direction of the shell, and / or an annular groove is provided between the negative electrode disk body and the pin portion.

[0016] In some embodiments, there is a preset gap between the winding core body and the shell, and a second flow gap is provided between the negative electrode disk and the thermal conductive gasket, one end of the preset gap is connected to the first flow gap, and the other end of the preset gap flows with the second flow gap.

[0017] In some embodiments, the top cover assembly includes a top cover sheet and a pole, the pole is connected to the top cover sheet, the top cover sheet is connected to the shell, the top cover sheet is in contact with the thermally conductive gasket, a step surface is provided on a side of the pole adjacent to the thermally conductive gasket, a second step portion is provided on a side of the positive electrode conductor adjacent to the top cover sheet, the second step portion is penetrated in the pole, and an outer surface of the second step portion is in contact with the step surface in the pole,

[0018] And / or, the cross-sectional area of ​​the second step portion gradually decreases in a direction approaching the pole.

[0019] In some embodiments, a pole hole and a receiving groove are provided in the pole, the receiving groove is connected to one end of the pole hole, the other end of the pole hole is connected to the guide hole, and the receiving groove is located on a side away from the positive guide.

[0020] The battery cell also includes a sealing assembly, which includes a first sealing nail and a second sealing nail. The first sealing nail extends into the pole hole through the receiving groove to seal the pole hole, and the second sealing nail is arranged in the receiving groove to seal the receiving groove.

[0021] In some embodiments, the top cover assembly further includes a sealing ring disposed between the pole and the top cover sheet.

[0022] In some embodiments, a pressure relief notch is provided at one end of the shell away from the top cover assembly.

[0023] A battery pack according to an embodiment of the present invention includes a battery cell as described in any of the above embodiments.

[0024] The vehicle according to the embodiment of the present invention includes the battery pack as described in the above embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of a battery cell according to an embodiment of the present invention.

[0026] Figure 2 is an exploded view of a battery cell according to an embodiment of the present invention.

[0027] Figure 3 yes Figure 1 Front view of the battery cell shown in .

[0028] Figure 4 Schematic diagram of the structure of the winding core according to an embodiment of the present invention.

[0029] Figure 5 yes Figure 4 Front view of the winding core shown in .

[0030] Figure 6 yes Figure 4 Bottom view of the winding core shown in .

[0031] Figure 7 yes Figure 4 A top view of the winding core shown in FIG.

[0032] Figure 8 yes Figure 3 A cross-sectional view of the cell AA section is shown in FIG.

[0033] Fig. 9 yes Figure 8 A partial enlarged view of area B is shown in FIG.

[0034] Fig.10 yes Figure 8 A partial enlarged view of region C is shown in FIG.

[0035] Fig.11 4 is a top view of a housing according to an embodiment of the present invention.

[0036] Fig.12 Schematic diagram of the structure of the positive electrode assembly of an embodiment of the present invention.

[0037] Fig.13 yes Fig.12 A cross-sectional view of the positive electrode assembly is shown in FIG.

[0038] Fig.14 yes Fig.13 A partial enlarged view of area D is shown in FIG.

[0039] Fig.15 Schematic diagram of the structure of the negative electrode assembly of an embodiment of the present invention.

[0040] Fig.16 yes Fig.15 A top view of the negative electrode assembly shown in FIG.

[0041] Fig.17 yes Fig.16 A cross-sectional view of section EE is shown in FIG.

[0042] Fig.18 yes Fig.17 A partial enlarged view of region F is shown in FIG.

[0043] Fig.19 is an exploded view of a top cover assembly according to an embodiment of the present invention.

[0044] Fig. 20 4 is a top view of a top cover assembly according to an embodiment of the present invention.

[0045] Fig.21 yes Fig. 20 GG cross-sectional view shown in .

[0046] Fig. 22 Schematic diagram of the structure of a thermally conductive gasket according to an embodiment of the present invention.

[0047] Reference numerals:

[0048] Shell 100, winding core 200, positive electrode assembly 300, top cover assembly 400, insulating gasket 500, negative electrode assembly 600, thermal conductive gasket 700, sealing assembly 800,

[0049] Positive electrode current collecting disc 1, positive electrode disc body 101, positive electrode welding portion 102, positive electrode boss 13,

[0050] Positive electrode guide post 2, first step portion 21, guide post hole 22, second step portion 23,

[0051] The winding core body 3, the positive electrode tab 4, the negative electrode tab 5,

[0052] Negative electrode current collecting plate 6, negative electrode plate body 61, negative electrode welding portion 62, negative electrode boss 63, pin portion 64, annular groove 65,

[0053] Top cover sheet 7,

[0054] Pole 8, pole hole 81, receiving groove 82,

[0055] A first sealing nail 9, a second sealing nail 10, a sealing ring 11, and a pressure relief notch 12. DETAILED DESCRIPTION

[0056] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0057] like Figures 1 to 22As shown, the battery cell of the embodiment of the present invention includes a shell 100, a winding core 200, a positive electrode assembly 300 and a top cover assembly 400. The winding core 200 is arranged in the shell 100, and has a center hole on the winding core 200, and the center hole passes through the winding core 200 along the length direction of the shell 100. The positive electrode assembly 300 is arranged in the shell 100. The positive electrode assembly 300 includes a positive current collecting disk 1 and a positive electrode guide 2. The positive current collecting disk 1 is connected to one end of the positive electrode guide 2, the positive current collecting disk 1 is connected to the winding core 200, and the positive electrode guide 2 passes through the center hole. The top cover assembly 400 is sleeved on the positive electrode guide 2, and the top cover assembly 400 and the positive current collecting disk 1 are arranged opposite to each other in the length direction of the shell 100.

[0058] Specifically, Figure 1 and Figure 2 As shown, one end of the shell 100 has an opening, and the other end of the shell 100 is closed, the winding core 200 is arranged in the shell 100, the positive current collecting plate 1 is located between the bottom of the winding core 200 and the inner bottom surface of the shell 100, the positive electrode guide column 2 is passed through the center hole, and the upper end of the positive electrode guide column 2 extends out of the center hole and is connected to the top cover assembly 400.

[0059] The lower end of the positive electrode lead 2 is inserted into the positive electrode current collecting disc 1 and the two are welded together, and the positive electrode current collecting disc 1 and the bottom of the winding core 200 are welded together.

[0060] In the battery cell of the embodiment of the present invention, the positive electrode guide post 2 is arranged inside the winding core 200, which can support and position the winding core 200, thereby improving the matching accuracy between the winding core 200 and the positive electrode guide post 2 and the installation accuracy of the winding core 200 in the shell 100. The positive electrode guide post 2 is connected to the top cover assembly 400. By utilizing the guiding function of the positive electrode guide post 2, the matching accuracy between the positive electrode guide post 2 and the top cover assembly 400 can be improved, thereby improving the matching accuracy between the winding core 200 and the top cover assembly 400 and between the top cover assembly 400 and the shell 100, thereby improving the yield rate of battery cell welding.

[0061] In some embodiments, the winding core 200 includes a winding core body and a positive electrode tab 4, the positive electrode tab 4 is connected to the winding core body, and the positive electrode tab 4 is connected to the positive electrode collecting plate 1, the positive electrode tab 4 is an annular tab, the inner ring of the positive electrode tab 4 has a diameter A, and 6mm≤A≤25mm.

[0062] It should be noted that the core body is formed by staggered stacking and winding of multiple layers of positive electrode sheets, multiple layers of negative electrode sheets and multiple layers of separators, and a center hole is left in the middle of the core body.

[0063] Specifically, Figures 4 to 7 As shown, the positive electrode tab 4 is arranged at the lower end of the winding core body, the positive electrode collector plate 1 is welded to the positive electrode tab 4 , and the upper end surface of the positive electrode collector plate 1 is in contact with the lower end surface of the positive electrode tab 4 .

[0064] like Figure 6 As shown, the positive electrode lug 4 is an annular lug, and the inner ring diameter of the positive electrode lug 4 is A, and A can be 6mm, 10mm, 15mm, 20mm or 25mm. It should be noted that since the positive electrode guide column 2 needs to pass through the positive electrode lug 4, when the inner ring diameter of the positive electrode lug 4 is too small, it will affect the smoothness of the positive electrode guide column 2 passing through the winding core body, and will also cause the size of the positive electrode guide column 2 to be reduced, affecting the supporting effect of the positive electrode guide column 2 on the winding core body. Conversely, when the inner ring size of the positive electrode lug 4 is too large, the area of ​​the annular surface of the positive electrode lug 4 is smaller, affecting the conductive performance of the battery cell.

[0065] Optionally, the outer ring diameter of the positive electrode tab 4 is smaller than the diameter of the core body. In other words, there is no positive electrode tab 4 in the edge area of ​​the core body, thereby preventing the positive electrode tab 4 from contacting the shell 100 and affecting the conductive efficiency of the battery cell.

[0066] In some embodiments, the battery cell also includes an insulating gasket 500, which is arranged between the positive current collecting disk 1 and the shell 100. The positive current collecting disk 1 includes a positive disk body 101, a positive welding portion 102 and a positive boss 13. The positive disk body 101 and the positive welding portion 102 are in contact with the positive electrode ear 4. The positive boss 13 protrudes in the length direction of the shell 100 away from the winding core 200. The positive boss 13 abuts against the insulating gasket 500, and / or a groove is opened on the positive disk body 101.

[0067] Specifically, Figure 2 As shown, the insulating gasket 500 is arranged at the bottom of the positive electrode current collecting disk 1. For example, the insulating gasket 500 is made of an insulating material, and the insulating gasket 500 has a high thermal conductivity, and can conduct the heat generated by the core 200 to the shell 100, thereby improving the heat exchange between the positive end of the core 200 and the shell 100, and can also conduct the heat inside the core 200 to the shell 100 through the positive electrode guide column 2 and then take the heat away through the water cooling plate of the system, thereby improving the uniformity of the temperature inside and outside the battery.

[0068] like Figures 8 to 12 As shown, the positive electrode welding portion 102 is formed on the positive electrode disc 101. In other words, the positive electrode disc 101 has a positive electrode welding portion 102. When the positive current collecting disc 1 is welded to the positive electrode tab 4, the positive electrode welding portion 102 on the positive electrode disc 101 is connected to the positive electrode tab 4, and the positive electrode boss 13 extends from top to bottom.

[0069] Optionally, the number of positive electrode bosses 13 may be multiple, and the multiple positive electrode bosses 13 are arranged at intervals in the circumferential direction of the positive electrode disc 101. For example, the number of positive electrode bosses 13 is three, and the three positive electrode bosses 13 are arranged at intervals of 120° in the circumferential direction of the positive electrode disc 101. It should be noted that a groove may be provided on the positive electrode welding portion 102, and the groove passes through the positive electrode disc 101, or a groove is provided on the positive electrode boss 13, or a groove is provided on the positive electrode disc 101.

[0070] By providing a groove on the positive electrode disc 101 or the positive electrode boss 13 , the weight of the positive electrode disc 101 or the positive electrode boss 13 can be reduced, which is beneficial to achieving lightweight of the battery cell.

[0071] By arranging the positive electrode boss 13 on the positive electrode disk 101, the fixing stability of the core 200 can be improved, thereby ensuring the fitting accuracy between the core 200 and the shell 100. When the fitting accuracy between the core 200 and the shell 100 is improved, the fitting accuracy between the positive electrode guide column 2 and the core 200, between the positive electrode guide column 2 and the top cover assembly 400, and between the top cover assembly 400 and the shell 100 is further improved.

[0072] In some embodiments, a first step portion 21 is provided on one side of the positive electrode lead 2 adjacent to the positive electrode disc 101 , and the first step portion 21 penetrates the positive electrode disc 101 .

[0073] Specifically, Fig.13 and Fig.14 As shown, the lower end of the positive electrode guide post 2 is provided with a first step portion 21, the first step portion 21 is provided through the middle of the positive electrode disc 101, and the first step portion 21 has a first step surface. When the positive electrode guide post 2 is connected to the positive electrode disc 101, the first step surface abuts against the upper end surface of the positive electrode disc 101. By providing the first step portion 21 on the positive electrode guide post 2, the matching accuracy between the positive electrode guide post 2 and the positive electrode disc 101 can be improved.

[0074] In some embodiments, the positive electrode guide column 2 has a guide column hole 22, which passes through the positive electrode guide column 2 along the length direction of the shell 100, and there is a first flow gap between the positive electrode disk 101 and the insulating gasket 500, and the guide column hole 22 is connected to the first flow gap.

[0075] Specifically, Fig.13As shown, the guide post hole 22 passes through the positive electrode guide post 2 in the up-down direction. Since the positive electrode boss 13 extends from top to bottom, a first flow gap is formed between the positive electrode disc 101 and the insulating gasket 500. The first flow gap is connected to the guide post hole 22. The electrolyte can be injected into the shell 100 through the guide post hole 22. The electrolyte flows through the first flow gap, thereby infiltrating the winding core 200. By providing the guide post hole 22, it is convenient to inject the electrolyte into the shell 100, and through the first flow gap, it is convenient to infiltrate the winding core 200.

[0076] In some embodiments, the winding core 200 also includes a negative electrode tab 5, which is connected to the winding core 200 body, and the negative electrode tab 5 and the positive electrode tab 4 are arranged relative to each other in the length direction of the shell 100, the negative electrode tab 5 is an annular tab, the inner ring of the negative electrode tab 5 has a diameter B, and 10mm≤B≤25mm, and / or the outer ring of the negative electrode tab 5 has a diameter less than or equal to the diameter of the winding core 200 body.

[0077] Specifically, Figures 4 to 7 As shown, the negative electrode tab 5 is arranged at the upper end of the winding core 200 body, and the negative electrode tab 5 is an annular tab. The diameter of the inner ring of the negative electrode tab 5 is B, and B can be 10mm, 15mm, 20mm or 25mm. It should be noted that since the positive electrode guide column 2 needs to pass through the negative electrode tab 5, when the inner ring diameter of the negative electrode tab 5 is too small, it will affect the smoothness of the positive electrode guide column 2 passing through the negative electrode current collecting plate 6, and will also cause the size of the positive electrode guide column 2 to be reduced, affecting the supporting effect of the positive electrode guide column on the winding core 200 body. Conversely, when the inner ring size of the negative electrode tab 5 is too large, the area of ​​the annular surface of the negative electrode tab 5 is smaller, affecting the conductive performance of the battery cell.

[0078] Optionally, the outer ring diameter of the negative electrode tab 5 is smaller than the diameter of the core 200 body. In other words, there is no negative electrode tab 5 in the edge area of ​​the core 200 body, thereby preventing the negative electrode tab 5 from contacting the shell 100 and affecting the conductive efficiency of the battery cell.

[0079] In some embodiments, the battery cell further includes a negative electrode assembly 600, which is connected to the negative electrode tab 5 and is located between the negative electrode tab 5 and the top cover assembly 400. The negative electrode assembly 600 includes a negative electrode collector plate 6 and a thermally conductive gasket 700, which is disposed between the negative electrode collector plate 6 and the top cover assembly 400.

[0080] Specifically, Figure 2 As shown, the negative electrode collector plate 6 is connected to the negative electrode ear 5, and the thermal conductive gasket 700 is arranged between the negative electrode collector plate 6 and the top cover assembly 400. For example, the thermal conductive gasket 700 is made of an insulating material, and the thermal conductive gasket 700 has a high thermal conductivity, which can conduct the heat generated by the core 200 to the shell 100.

[0081] The negative electrode current collecting disc 6 includes a negative electrode disc body 61 and a negative electrode boss 63. The negative electrode disc body 61 contacts the negative electrode ear 5. The negative electrode boss 63 protrudes in the length direction of the shell 100 away from the winding core 200. The negative electrode boss 63 abuts against the thermal conductive gasket 700, and / or a groove is opened on the negative electrode disc body 61.

[0082] like Figures 15 to 18 As shown, the negative electrode disc 61 has a through hole in the middle, which can avoid the pole 8 to avoid short circuit, and at the same time cover the negative electrode ear 5 on the end face of the winding core 200.

[0083] The negative electrode welding portion 62 is formed on the negative electrode disc 61. In other words, the negative electrode disc 61 has a negative electrode welding portion 62. When the negative electrode current collecting disc 6 is welded to the negative electrode tab 5, the negative electrode welding portion 62 on the negative electrode disc 61 is connected to the negative electrode tab 5, and the negative electrode boss 63 extends from bottom to top.

[0084] Optionally, the number of negative electrode bosses 63 may be multiple, and the multiple negative electrode bosses 63 are arranged at intervals in the circumferential direction of the negative electrode disc 61. For example, the number of negative electrode bosses 63 is three, and the three negative electrode bosses 63 are arranged at intervals of 120° in the circumferential direction of the negative electrode disc 61. It should be noted that a groove may be provided on the negative electrode welding portion 62, and the groove passes through the negative electrode disc 61, or a groove is provided on the negative electrode boss 63, or a groove is provided on both the negative electrode welding portion 62 and the negative electrode boss 63.

[0085] By providing a groove on the negative electrode disc 61 or the negative electrode boss 63 , the weight of the negative electrode disc 61 or the negative electrode boss 63 can be reduced, which is beneficial to achieving lightweight of the battery cell.

[0086] By providing a negative electrode boss 63 on the negative electrode disc 61, the fixing stability of the winding core 200 can be improved, thereby ensuring the fitting accuracy between the winding core 200 and the shell 100. When the fitting accuracy between the winding core 200 and the shell 100 is improved, the fitting accuracy between the positive electrode guide column and the winding core 200, between the positive electrode guide column and the top cover assembly 400, and between the top cover assembly 400 and the shell 100 is further improved.

[0087] In some embodiments, the negative electrode current collecting disk 6 also includes a pin portion 64, which surrounds the negative electrode disk body 61, and the pin portion 64 extends in the length direction of the shell 100 in a direction away from the winding core 200, and / or, an annular groove 65 is provided on the negative electrode disk body 61, and the annular groove 65 is provided between the pin portion 64 and the negative electrode welding portion 62.

[0088] Specifically, Fig.15 and Fig.18As shown, the pin portion 64 surrounds the outer peripheral surface of the negative electrode disc body 61, and the pin portion 64 extends from bottom to top. When the negative electrode current collecting disc 6 is installed in the shell 100, the outer peripheral surface of the pin portion 64 contacts the inner wall surface of the shell 100. The tight fit between the pin portion 64 and the shell 100 can ensure the alignment of the winding core 200 and the shell 100. The top cover assembly 400 cooperates with the positive electrode guide column 2 during the assembly process to play a guiding role, which can improve the fitting accuracy of the cover plate and the shell 100.

[0089] like Fig.15 As shown, the annular groove 65 surrounds the bottom of the pin portion 64, and the cross-sectional area of ​​the annular groove 65 gradually decreases from top to bottom to form an inverted trapezoid. By opening the annular groove 65 on the negative plate 61, the space occupied by the pin portion 64 in the length space of the battery cell can be reduced. At the same time, the annular groove 65 can also strengthen the local structural strength of the pin portion 64.

[0090] Optionally, the pin portion 64 is integrally formed with the negative electrode disc body 61 , for example, the pin portion 64 is integrally formed with the negative electrode disc body 61 by stamping, thereby improving the structural strength of the pin portion 64 .

[0091] In some embodiments, there is a preset gap between the winding core 200 body and the shell 100, and a second flow gap is provided between the negative electrode disc 61 and the thermal conductive gasket 700. One end of the preset gap is connected to the first flow gap, and the other end of the preset gap flows with the second flow gap.

[0092] Specifically, Figure 8 and Fig. 9 As shown, since the negative electrode boss 63 extends from bottom to top, a second flow gap is formed between the negative electrode disk 61 and the thermally conductive gasket 700, and a preset gap is provided between the outer peripheral surface of the winding core 200 body and the inner wall surface of the shell 100. The second flow gap is connected to the upper end of the preset gap, and the first flow gap is connected to the lower end of the preset gap. The electrolyte that enters the interior of the shell 100 through the guide column hole 22 infiltrates the winding core 200 through the first flow gap, the second flow gap and the preset gap.

[0093] In some embodiments, the top cover assembly 400 includes a top cover sheet 7 and a pole 8, the pole 8 is connected to the top cover sheet 7, the top cover sheet 7 is connected to the shell 100, the top cover sheet 7 is in contact with the thermal conductive gasket 700, a step surface is provided on the side of the pole 8 adjacent to the thermal conductive gasket 700, a second step portion 23 is provided on the side of the positive electrode conductor 2 adjacent to the top cover sheet 7, the second step portion 23 is penetrated in the pole 8, and the outer surface of the second step portion 23 is in contact with the step surface in the pole 8, and / or the cross-sectional area of ​​the second step portion 23 gradually decreases in the direction approaching the pole 8.

[0094] Specifically, Figures 19 to 21As shown, the lower end surface of the top cover sheet 7 contacts the upper end surface of the thermal conductive gasket 700. When the top cover assembly 400 is connected to the shell 100, the outer peripheral surface of the top cover sheet 7 contacts the inner wall surface of the shell 100, and the upper end surface of the top cover sheet 7 is flush with the upper end surface of the shell 100. The lower end of the pole 8 is inserted into the top cover plate, and the pole 8 is sleeved outside the positive electrode conductor 2. The upper end of the positive electrode conductor 2 is provided with a second step portion 23, and a step surface is provided in the pole 8. The second step portion 23 extends into the pole 8, and the second step portion 23 contacts the step surface.

[0095] It should be noted that the positive electrode conductor 2 and the pole 8 are sealed and connected to each other by welding.

[0096] The cross-sectional area of ​​the second step portion 23 gradually decreases from bottom to top. In other words, the outer surface of the second step portion 23 is a conical surface, so as to prevent the positive electrode conductor 2 from getting caught on the separator of the center hole of the winding core 200 when passing through the center hole of the winding core 200.

[0097] Optionally, the edge of the top cover sheet 7 has a positioning step. When the top cover sheet 7 is connected to the shell 100, the outer surface of the positioning step matches the inner wall of the shell 100 and is sealed and welded.

[0098] In some embodiments, a pole hole 81 and a receiving groove 82 are provided in the pole 8, the receiving groove 82 is connected to one end of the pole hole 81, and the other end of the pole hole 81 is connected to the guide hole 22, and the receiving groove 82 is located on the side away from the positive guide 2.

[0099] Specifically, Fig.21 As shown, the upper end of the positive electrode guide post 2 extends into the pole hole 81, the lower end of the accommodating groove 82 is connected to the pole hole 81, the upper end of the accommodating groove 82 is connected to the outside, and the lower end of the pole hole 81 is connected to the guide post hole 22. It should be noted that electrolyte can be added to the guide post hole 22 through the accommodating groove 82 and the pole hole 81.

[0100] The battery cell also includes a sealing assembly 800 , which includes a first sealing nail 9 and a second sealing nail 10 . The first sealing nail 9 extends into the pole hole 81 through the receiving groove 82 to seal the pole hole 81 , and the second sealing nail 10 is arranged in the receiving groove 82 to seal the receiving groove 82 .

[0101] Specifically, Figure 2 and Fig.21 As shown, the first sealing nail 9 is a rubber nail, and the lower end of the first sealing nail 9 extends into the guide post hole 22, the second sealing nail 10 is an aluminum nail, the second sealing nail 10 is arranged in the receiving groove 82, and the second sealing nail 10 is welded to the pole 8. By arranging the first sealing nail 9 and the second sealing nail 10, the guide post hole 22, the pole hole 81 and the receiving groove 82 can be sealed to improve the sealing inside the battery cell.

[0102] like Fig. 22 As shown, the thermal conductive gasket 700 has a through hole in the middle, and the pole 8 extends into the through hole.

[0103] In some embodiments, the top cover assembly 400 further includes a sealing ring 11 , which is disposed between the pole 8 and the top cover sheet 7 .

[0104] Specifically, Fig.19 and Fig.21 As shown, the sealing ring 11 is sandwiched between the top cover sheet 7 and the pole 8, which can improve the sealing between the top cover sheet 7 and the pole 8 and also play an insulating role.

[0105] In some embodiments, a pressure relief notch 12 is provided at one end of the housing 100 away from the top cover assembly 400 .

[0106] Specifically, Fig.11 As shown, a pressure relief notch 12 is provided at the bottom of the shell 100. For example, the pressure relief notch 12 is an annular notch. By designing the pressure relief notch 12 at the bottom of the shell 100, the gas inside the shell 100 can be removed in time when the battery cell thermally runs away to reduce the risk of thermal runaway.

[0107] A battery pack according to an embodiment of the present invention includes a battery cell according to any one of the above embodiments.

[0108] The vehicle according to the embodiment of the present invention includes the battery pack according to the above embodiment.

[0109] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0110] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0111] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0112] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0113] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0114] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A battery cell, characterized in that: include: case; A winding core, the winding core is arranged in the shell, and the winding core has a central hole, and the central hole penetrates the winding core along the length direction of the shell; A positive electrode assembly, the positive electrode assembly is arranged in the shell, the positive electrode assembly includes a positive electrode collector and a positive electrode guide, the positive electrode collector is connected to one end of the positive electrode guide, and the positive electrode collector is connected to the winding core, and the positive electrode guide passes through the center hole; A top cover assembly is sleeved on the positive electrode guide column, and the top cover assembly and the positive electrode current collecting plate are arranged opposite to each other in the length direction of the shell.

2. The battery cell according to claim 1, characterized in that: The winding core includes a winding core body and a positive electrode tab, wherein the positive electrode tab is connected to the winding core body and the positive electrode tab is connected to the positive current collecting disk, the positive electrode tab is an annular tab, and the diameter of the inner ring of the positive electrode tab is A, and 6mm≤A≤25mm.

3. The battery cell according to claim 2, characterized in that: It also includes an insulating gasket, which is arranged between the positive current collector disk and the shell. The positive current collector disk includes a positive disk body and a positive boss. The positive disk body is in contact with the positive pole ear. The positive boss protrudes in the length direction of the shell away from the winding core. The positive boss abuts against the insulating gasket, and / or a groove is opened on the positive disk body.

4. The battery cell according to claim 3, characterized in that: A first step portion is provided on a side of the positive electrode guide column adjacent to the positive electrode disc, and the first step portion penetrates the positive electrode disc.

5. The battery cell according to claim 3, characterized in that: The positive electrode guide post has a guide post hole therein, the guide post hole penetrates the positive electrode guide post along the length direction of the shell, a first flow gap is provided between the positive electrode disc and the insulating gasket, and the guide post hole is connected to the first flow gap.

6. The battery cell according to claim 5, characterized in that: The winding core also includes a negative electrode tab, which is connected to the winding core body, and the negative electrode tab and the positive electrode tab are arranged relative to each other in the length direction of the shell, the negative electrode tab is an annular tab, the diameter of the inner ring of the negative electrode tab is B, and 10mm≤B≤25mm, and / or the diameter of the outer ring of the negative electrode tab is less than or equal to the diameter of the winding core body.

7. The battery cell according to claim 6, characterized in that: It also includes a negative electrode assembly, the negative electrode assembly is connected to the negative electrode tab, and the negative electrode assembly is located between the negative electrode tab and the top cover assembly, The negative electrode assembly includes a negative electrode collector disk and a thermally conductive gasket, wherein the thermally conductive gasket is arranged between the negative electrode collector disk and the top cover assembly, the negative electrode collector disk includes a negative electrode disk body and a negative electrode boss, the negative electrode disk body is in contact with the negative electrode ear, the negative electrode boss protrudes in the length direction of the shell along the direction away from the winding core, the negative electrode boss abuts against the thermally conductive gasket, and / or a groove is opened on the negative electrode disk body.

8. The battery cell according to claim 7, characterized in that: The negative electrode current collector disk further includes a pin portion, which surrounds the negative electrode disk body and extends in a direction away from the winding core in the length direction of the shell, and / or an annular groove is provided between the negative electrode disk body and the pin portion.

9. The battery cell according to claim 7, characterized in that: A preset gap is provided between the winding core body and the shell, a second flow gap is provided between the negative electrode disc and the thermally conductive gasket, one end of the preset gap is connected to the first flow gap, and the other end of the preset gap is in communication with the second flow gap.

10. The battery cell according to claim 7, characterized in that: The top cover assembly includes a top cover sheet and a pole, the pole is connected to the top cover sheet, the top cover sheet is connected to the shell, the top cover sheet contacts the thermally conductive pad, a step surface is provided on a side of the pole adjacent to the thermally conductive pad, a second step portion is provided on a side of the positive electrode conductor adjacent to the top cover sheet, the second step portion is penetrated in the pole, and an outer surface of the second step portion contacts the step surface in the pole, And / or, the cross-sectional area of ​​the second step portion gradually decreases in a direction approaching the pole.

11. The battery cell according to claim 10, characterized in that: The pole is provided with a pole hole and a receiving groove, the receiving groove is connected with one end of the pole hole, the other end of the pole hole is connected with the guide hole, and the receiving groove is located on a side away from the positive guide. The battery cell also includes a sealing assembly, which includes a first sealing nail and a second sealing nail. The first sealing nail extends into the pole hole through the receiving groove to seal the pole hole, and the second sealing nail is arranged in the receiving groove to seal the receiving groove.

12. The battery cell according to claim 10, characterized in that: The top cover assembly also includes a sealing ring, which is arranged between the pole and the top cover sheet.

13. The battery cell according to any one of claims 1 to 12, characterized in that: A pressure relief notch is provided at one end of the shell away from the top cover assembly.

14. A battery pack, characterized in that: Comprising the battery cell as claimed in any one of claims 1 to 13.

15. A vehicle, characterized in that: Comprising the battery pack as claimed in claim 14.

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