Secondary battery, battery pack and energy storage box

Abstract

The utility model provides a secondary battery, a battery pack and an energy storage box, the secondary battery comprises an end cover assembly and a top patch, and the top patch is located at one side, far away from the interior of the secondary battery, of the end cover assembly. The end cover assembly comprises a top cover and a pole, and the pole is installed on the top cover through a fixing piece. The top cover is provided with at least one first sunken part, the first sunken part is sunken towards one side close to the interior of the secondary battery, the bottom wall of the first sunken part is provided with a mounting hole, and the pole is sleeved with the mounting hole. A sealing piece is arranged along the circumferential direction of the pole, and the fixing piece is sleeved with the pole. One of the fixing piece and the pole is provided with a limiting recess, and the other one is provided with a limiting bulge. And the limiting bulge extends into the limiting recess along the radial direction of the pole. The pole protrudes out of the top patch, the distance between the upper surface of the pole and the upper surface of the top patch is a, and a is larger than 0 and smaller than or equal to 2 mm. Through the design, the structure of the secondary battery can be more compact, so that the capacity and the energy density of the secondary battery can be improved.

Description

Technical Field

[0001] This application relates to the technical field of energy storage, and particularly to a secondary battery, a battery pack, and an energy storage box. Background Art

[0002] A secondary battery is a rechargeable battery that can be reused and has reversibility. It is a reversible battery that can be used again after charging after discharging. A secondary battery generally includes a housing, a cell assembly, and a top cover assembly. The top cover assembly and the housing are used to encapsulate the cell assembly. The cell assembly includes one or more bare cells. The tabs of the bare cells are connected to the terminals of the top cover assembly through connecting members. The cells are mainly responsible for storing electrical energy and converting chemical energy into electrical energy through chemical reactions. The terminals can serve as the positive or negative electrode of the secondary battery and are used to transmit current. The capacity and energy density of a secondary battery are important indicators for evaluating the performance of the secondary battery. Utility Model Content

[0003] This application provides a secondary battery, a battery pack, and an energy storage box for improving the capacity and energy density of the secondary battery.

[0004] This application provides a secondary battery, which includes:

[0005] An end cover assembly, the end cover assembly includes a top cover and a terminal. The terminal is installed on the top cover through a fixing member;

[0006] A top patch, the top patch is located on the side of the top cover away from the inside of the secondary battery;

[0007] Wherein, the top cover is provided with at least one first recessed portion, the first recessed portion recesses toward the side close to the inside of the secondary battery. The bottom wall of the first recessed portion is provided with a mounting hole. At least part of the terminal is sleeved with the mounting hole. A sealing member is arranged along the circumferential direction of the terminal. The fixing member is located in the first recessed portion and is sleeved with the terminal. Among the fixing member and the terminal, one is provided with a limiting recess, and the other is provided with a limiting protrusion. At least part of the limiting protrusion extends radially into the limiting recess along the terminal. Along the thickness direction of the end cover assembly, the terminal protrudes from the top patch. The distance between the upper surface of the terminal and the upper surface of the top patch is a, and 0 < a ≤ 2 mm.

[0008] In a possible implementation manner, along the thickness direction of the end cover assembly, the distance between the upper surface of the terminal and the upper surface of the top cover is b, and 0.5 mm ≤ b ≤ 3 mm.

[0009] In a possible implementation manner, the secondary battery further includes a connecting member and a cell assembly. The cell assembly includes tabs. The terminal is electrically connected to the tabs through the connecting member;

[0010] The connecting piece is provided with a connecting groove, which is recessed in a direction away from the end cover assembly. The pole extends into the connecting groove along the thickness direction of the end cover assembly and is connected to the inner wall of the connecting groove.

[0011] In a possible implementation, the battery cell assembly includes a first battery cell and a second battery cell, the first battery cell has a first pole lug, the second battery cell has a second pole lug, the connector includes a pole column connection portion, a first pole lug connection portion and a second pole lug connection portion, the first pole lug connection portion is electrically connected to the first pole lug, and the second pole lug connection portion is electrically connected to the second pole lug;

[0012] Along the width direction of the end cover assembly, the first pole lug connection portion and the second pole lug connection portion are located on opposite sides of the pole connection portion, the connection groove is arranged on the side of the pole connection portion facing the pole, and the position of the pole connection portion corresponding to the connection groove is protruded on the side of the pole connection portion facing the battery cell assembly.

[0013] In a possible implementation manner, along the thickness direction of the end cover assembly, the depth of the connection groove is 1 mm to 6 mm.

[0014] In a possible implementation, the first recessed portion is a stepped groove, and a side of the fixing member facing the side wall of the first recessed portion is a stepped surface, and the stepped surface is in contact with the side wall of the stepped groove.

[0015] In a possible embodiment, the seal includes a main body portion and a second extension portion that are connected to each other, the cross-sectional area of ​​the main body portion is larger than the cross-sectional area of ​​the second extension portion, the main body portion is located on a side of the top cover close to the interior of the secondary battery, the second extension portion extends in a direction close to the top patch and is arranged along the circumference of the pole, and at least a portion of the second extension portion extends into the mounting hole and is located between the pole and the hole wall of the mounting hole.

[0016] In a possible implementation manner, the end cover assembly includes a lower plastic part, which is located on a side of the top cover facing the inside of the secondary battery and is sleeved on the pole;

[0017] The lower plastic part has a second recessed portion, which is recessed in a direction away from the top cover and is used to accommodate the first recessed portion;

[0018] The lower plastic part is sleeved with the pole through the second recessed portion, and the sealing member is arranged along the circumference of the pole and located between the pole and the side wall of the second recessed portion.

[0019] A second aspect of the present application provides a battery pack, the battery pack comprising at least one battery module, the battery module comprising at least one secondary battery;

[0020] Wherein, the secondary battery is any one of the secondary batteries described above.

[0021] A third aspect of the present application provides an energy storage box, which includes an inverter, a battery management system and at least one battery pack, wherein the battery pack is the battery pack described above.

[0022] The present application provides a secondary battery, a battery pack and an energy storage box. The secondary battery includes an end cap assembly and a top patch. The top patch is located on the side of the end cap assembly away from the inside of the secondary battery. The end cap assembly includes a top cap and a pole, and the pole is mounted on the top cap through a fixing member. The top cap is provided with at least one first recessed portion, the first recessed portion is recessed toward the side close to the inside of the secondary battery, the bottom wall of the first recessed portion is provided with a mounting hole, and the pole is sleeved with the mounting hole. A sealing member is provided along the circumference of the pole, and the fixing member is located in the first recessed portion and sleeved with the pole. One of the fixing member and the pole is provided with a limited recess, and the other is provided with a limited protrusion. The limiting protrusion extends into the limiting recess along the radial direction of the pole. Along the thickness direction of the end cap assembly, the pole protrudes from the top patch, and the distance between the upper surface of the pole and the upper surface of the top patch is a, 0<a≤2 mm. Such a design can make the structure of the secondary battery more compact, which is conducive to improving the capacity and energy density of the secondary battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An exploded view of a partial structure of a secondary battery provided in this application;

[0024] Figure 2 A schematic diagram of the top cover provided for this application;

[0025] Figure 3 A schematic diagram of the pole provided for this application;

[0026] Figure 4 A schematic diagram of the fixing member provided for this application;

[0027] Figure 5 A partial cross-sectional view of the secondary battery provided in this application;

[0028] Figure 6 A partial cross-sectional view of the secondary battery provided in the present application from another perspective;

[0029] Figure 7 A schematic diagram of the connector provided for this application;

[0030] Figure 8 A schematic diagram of the lower plastic part provided for this application;

[0031] Fig. 9 A schematic diagram of a secondary battery provided in this application;

[0032] Fig.10 A schematic diagram of another embodiment of a secondary battery provided in the present application;

[0033] Fig.11 A schematic diagram of another embodiment of a secondary battery provided in the present application;

[0034] Fig.12 A schematic diagram of the battery pack provided for this application;

[0035] Fig.13 An exploded view of the battery pack provided for this application;

[0036] Fig.14 A schematic diagram of the energy storage box provided in this application.

[0037] Reference numerals

[0038] 1-end cover assembly;

[0039] 11-top cover;

[0040] 111- first recessed portion;

[0041] 111a-mounting hole;

[0042] 12-pole;

[0043] 121-limiting depression;

[0044] 13-fixing parts;

[0045] 131-limiting protrusion;

[0046] 14- Seal;

[0047] 141-Ontology part;

[0048] 142- second extension;

[0049] 15-lower plastic part;

[0050] 151 - second recessed portion;

[0051] 2- Top patch;

[0052] 21- third recessed portion;

[0053] 3-Connectors;

[0054] 31-pole connection part;

[0055] 311-connection slot;

[0056] 32-first pole lug connection portion;

[0057] 33- second pole lug connection portion;

[0058] 4-Battery cell assembly;

[0059] 41-first battery cell;

[0060] 411-first pole lug;

[0061] 42- second battery cell;

[0062] 412- second pole lug;

[0063] 5-Paper;

[0064] 6-Battery pack;

[0065] 7-Battery module;

[0066] 8-Energy storage box;

[0067] 9-Heat conducting parts. DETAILED DESCRIPTION

[0068] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0069] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0070] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0071] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0072] like Figure 1As shown, the embodiment of the present application provides a secondary battery, the secondary battery includes an end cap assembly 1 and a top patch 2, the top patch 2 is located on the side of the end cap assembly 1 away from the inside of the secondary battery, and is used to protect the structure of the secondary battery to reduce the impact of environmental factors on the secondary battery. The end cap assembly 1 includes a top cover 11 and a pole 12, and the pole 12 is installed on the top cover 11 through a fixing member 13. Figure 2 As shown, the top cover 11 is provided with at least one first recessed portion 111, and the number of the first recessed portions 111 can be set according to the number of poles 12. Usually, the secondary battery includes a positive pole 12 and a negative pole 12, and the top cover 11 is provided with two first recessed portions 111, and the positive pole 12 and the negative pole 12 are respectively matched with the corresponding first recessed portions 111. The first recessed portion 111 is recessed toward the side close to the interior of the secondary battery, and the bottom wall of the first recessed portion 111 is provided with a mounting hole 111a. The pole 12 extends into the first recessed portion 111 and partially passes through the mounting hole 111a, so that the pole 12 is sleeved with the mounting hole 111a. A sealing member 14 is provided along the circumference of the pole 12, and the fixing member 13 is located in the first recessed portion 111 and is sleeved with the pole 12. As shown Figure 3 and Figure 4 As shown, one of the fixing member 13 and the pole 12 is provided with a limiting recess 121, and the other is provided with a limiting protrusion 131. Figure 5 As shown, when the pole 12 and the fixing member 13 cooperate, the limiting protrusion 131 extends into the limiting recess 121 along the radial direction of the pole 12. Along the thickness direction of the end cover assembly 1, the pole 12 protrudes from the top patch 2, and the distance between the upper surface of the pole 12 and the upper surface of the top patch 2 is a, 0<a≤2 mm. The upper surface of the pole 12 is the surface of the pole 12 away from the inside of the secondary battery, which is usually used to connect with the bar 5. The upper surface of the top patch 2 is the surface of the top patch 2 away from the inside of the secondary battery. The fixing member 13 can be integrally injection molded. After the pole 12, the top cover 11, the sealing ring and other components are installed, injection molding is performed to relatively fix the pole 12 and the top cover 11.

[0073] The distance that the upper surface of the pole 12 protrudes relative to the upper surface of the top patch 2 can be 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, etc.

[0074] The fixing member 13 can be used to install the pole on the top cover 11 by injection molding. The limiting protrusion 131 and the limiting recess 121 cooperate with each other to increase the contact area between the fixing member 13 and the pole 12, thereby improving the stability of the connection. At the same time, the cooperation between the limiting protrusion 131 and the limiting recess 121 can also limit the pole 12, thereby reducing the possibility of the pole 12 being separated from the end cover assembly 1, and improving the position accuracy of the pole 12, reducing the possibility of the pole 12 shaking.

[0075] In the related art, the distance that the pole 12 of the secondary battery protrudes from the top patch 2 is usually about 5 mm, and such a design results in a relatively large thickness of the end cap assembly 1. When the height of the secondary battery is constant, the larger the space occupied by the end cap assembly 1, the more it will affect the space for accommodating structures such as the electrolyte, that is, the larger the thickness of the end cap assembly 1, the smaller the capacity of the secondary battery. In the scheme provided in the embodiment of the present application, the distance that the pole 12 protrudes from the top patch 2 does not exceed 2 mm. Therefore, the thickness of the end cap assembly 1 is small, so that the space occupied by the end cap assembly 1 can be reduced, which is conducive to increasing the space of the remaining part, so that the secondary battery can accommodate more electrolyte or larger bare cells, etc., to increase the capacity of the secondary battery. The fixing member 13 is processed by an integral injection molding method, and the injection molding method has the advantages of high automation and low production cost. The seal 14 is used to improve the sealing and insulation of the end cap assembly 1, reduce the influence of external factors on the inside of the secondary battery, and thus help to improve the performance and quality of the secondary battery.

[0076] In a possible implementation, along the thickness direction of the end cover assembly 1 , the distance between the upper surface of the pole 12 and the upper surface of the top cover 11 is b, and 0.5 mm≤b≤3 mm.

[0077] The upper surface of the top cover 11 is the surface of the top cover 11 facing the top patch 2, and the size of the pole 12 protruding from the top cover 11 can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, etc.

[0078] By reducing the protruding size of the pole 12 relative to the top cover 11, the size of the end cover assembly 1 in the thickness direction can be reduced, thereby reducing the space occupied by the end cover assembly 1, and further simplifying the space of the secondary battery, so that the secondary battery can accommodate more electrolyte and larger electrode sheets under the same volume, which is beneficial to increase the battery capacity by 2% to 3%, thereby improving the energy density of the secondary battery and better meeting actual usage needs.

[0079] like Figure 6 As shown, in a possible implementation, the secondary battery further includes a connector 3 and a cell assembly 4, the connector 3 is used to connect the cell assembly 4 and the pole 12, the cell assembly 4 includes at least one bare cell, the bare cell includes a positive electrode sheet, a negative electrode sheet and a separator, and is processed by winding, stacking, etc. The cell assembly 4 includes a tab, which can be connected to the connector 3 by welding, etc. Figure 7 As shown, the connector 3 is provided with a connecting groove 311, which is provided on the side of the connector 3 facing the pole 12 and is recessed in a direction away from the end cover assembly 1. Along the thickness direction of the end cover assembly 1, the pole 12 extends into the connecting groove 311 and is connected to the inner wall of the connecting groove 311, so that the pole 12 can be electrically connected to the pole lug through the connector 3.

[0080] By providing the connecting groove 311 in the connecting member 3, not only the connection accuracy between the connecting member 3 and the pole 12 can be improved, but also, since the connecting groove 311 is recessed toward one side of the interior of the secondary battery, the pole 12 can extend further into the interior of the secondary battery. When calculating the height of the secondary battery, the portion where the pole 12 and the connecting member 3 overlap in the height direction can be excluded from the total height. Therefore, the structure of the secondary battery is more compact, which is beneficial to improving the energy density of the secondary battery.

[0081] like Figure 6 As shown, in a possible manner, the battery cell assembly 4 includes a first battery cell 41 and a second battery cell 42, the first battery cell 41 includes a first pole ear 411, and the second battery cell 42 includes a second pole ear 412. Figure 7 As shown, the connector 3 includes a pole connecting portion 31, a first pole lug connecting portion 32 and a second pole lug connecting portion 33, the first pole lug connecting portion 32 and the first pole lug 411 are electrically connected, the second pole lug connecting portion 33 and the second pole lug 412 are electrically connected, and the pole connecting portion 31 and the pole 12 are electrically connected. Along the width direction of the end cap assembly 1, the first pole lug connecting portion 32 and the second pole lug connecting portion 33 are located on opposite sides of the pole connecting portion 31, the connecting groove 311 is provided on the side of the pole connecting portion 31 facing the pole 12, and the side of the pole connecting portion 31 facing the battery cell is protruded at a position corresponding to the connecting groove 311.

[0082] The first pole ear 411 may include a first positive pole ear and a first negative pole ear, and the second pole ear 412 may include a second positive pole ear and a second negative pole ear, the first positive pole ear and the second positive pole ear are connected to the same connector 3, and the first negative pole ear and the second negative pole ear are connected to the same connector 3. The secondary battery may include two connectors 3, which are respectively used to connect the positive pole ear and the negative pole ear of the battery cell assembly 4, the pole 12 electrically connected to the positive pole ear is the positive pole 12, and the pole 12 electrically connected to the negative pole ear is the negative pole 12.

[0083] Through such a design, the space between the pole lug connection parts can be utilized to realize the sinking setting of the pole 12. By sinking the pole 12, the protruding size of the pole 12 relative to the top cover 11 and the top patch 2 can be reduced, the space utilization rate can be improved, and the overall structure of the secondary battery can be made more compact, which is conducive to improving the energy density of the secondary battery. Moreover, the pole lug connection parts are located on opposite sides of the pole lug connection part 31, so the possibility of interference between the pole 12 and the pole lug when the pole 12 is sunk can be reduced, and the influence of the sinking setting of the pole 12 on the connection between the pole lug and the connector 3 can be reduced.

[0084] In a possible implementation, the depth of the connection groove 311 is 1 mm to 6 mm along the thickness direction of the end cap assembly 1. The thickness direction of the end cap is the thickness direction of the connector 3, and is also the height direction of the secondary battery. The depth of the connection groove 311 can be 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, etc.

[0085] According to the size of the pole 12 and the structural requirements of the secondary battery, the connection groove 311 of different depths can be set. The greater the depth of the connection groove 311, the greater the sinking distance of the pole 12, and the smaller the protruding size relative to the top cover 11 and the top patch 2. When the depth of the connection groove 311 is less than 1 mm, due to the small depth of the connection groove 311, the space for the pole 12 to sink is relatively small, and the impact on the thickness of the end cover assembly 1 is relatively small. When the depth of the connection groove 311 is greater than 6 mm, the depth of the connection groove 311 is large, and the distance that the pole 12 sinks is large, which is easy to interfere with the internal structure of the secondary battery, affecting the setting space of structures such as the pole ear, electrolyte and electrode sheet. Therefore, the depth of the connection groove 311 can be set to 1 mm to 6 mm.

[0086] In the solution provided in the embodiment of the present application, by designing the internal structure of the secondary battery, the space between the pole ears of the bare battery cell is utilized, and the connection groove 311 of the connector 3 is matched to enable the pole 12 to be sunken, so that the overall structure of the top cover assembly 1 is more compact, and the size occupied by the top cover assembly 1 in the height direction is reduced. Since the protruding size of the pole 12 relative to the top patch 2 is reduced, when the position of the upper surface of the pole 12 in the height direction of the secondary battery remains unchanged, compared with the secondary battery in the related art, the overall position of the top patch 2 and other components of the top cover assembly 1 is relatively high, and the space left for other components of the secondary battery is increased, so that the secondary battery can accommodate larger electrode sheets and more electrolyte. Therefore, the solution provided in the embodiment of the present application can increase the capacity of the secondary battery without increasing the overall external size of the secondary battery, thereby improving the energy density of the secondary battery, which is more in line with actual use requirements.

[0087] like Figure 5 As shown, in a possible implementation, the first recessed portion 111 is a stepped groove, and a side of the side wall of the fixing member 13 facing the first recessed portion 111 is a stepped surface, and the stepped surface is in contact with the side wall of the stepped groove.

[0088] By setting the first recessed portion 111 as a stepped groove, the area of ​​the side wall of the first recessed portion 111 can be increased, and the shape of the fixing member 13 is adapted to the first recessed portion 111, that is, the surface of the fixing member 13 is a stepped surface and fits the surface of the first recessed portion 111. Such a design can increase the contact area between the first recessed portion 111 and the fixing member 13, and enhance the stability of the connection between the two. At the same time, the first recessed portion 111 as a stepped groove can also facilitate positioning, which is more in line with actual use requirements.

[0089] like Figure 5 As shown, in a possible embodiment, the seal 14 includes a main body 141 and a second extension 142 connected to each other, the cross-sectional area of ​​the main body 141 is larger than the cross-sectional area of ​​the second extension 142, and the pole 12 is usually a cylindrical structure, and the seal 14 is sleeved on the outside of the pole 12 and is also a cylindrical structure. The main body 141 and the second extension 142 are arranged in sequence along the axial direction of the seal 14, and the radial dimension of the main body 141 is larger than the radial dimension of the second extension 142. The main body 141 is located on the side of the top cover 11 close to the inside of the secondary battery, and the second extension 142 extends in a direction close to the top patch 2 and is arranged along the circumference of the pole 12. At least part of the second extension 142 extends into the mounting hole 111a and is located between the pole 12 and the hole wall of the mounting hole 111a.

[0090] The main body 141 can not only seal but also limit. The second extension portion 142 extending into the mounting hole 111a can further improve the sealing of the secondary battery and reduce the possibility of secondary battery failure caused by contact between the pole 12 and other structures or materials.

[0091] like Figure 8 As shown, in a possible embodiment, the end cap assembly 1 includes a lower plastic part 15, which is located on the side of the top cover 11 facing the inside of the secondary battery and is sleeved with the pole 12. The lower plastic part 15 has a second recessed portion 151, which is arranged corresponding to the first recessed portion 111. The second recessed portion 151 is recessed in a direction away from the top cover 11 to accommodate the first recessed portion 111. The lower plastic part 15 is sleeved with the pole 12 through the second recessed portion 151, and the sealing member 14 is arranged along the circumference of the pole 12 and is located between the pole 12 and the side wall of the second recessed portion 151.

[0092] The lower plastic part 15 is used to reduce the possibility of short circuit between the pole ear and the top cover 11, so as to improve the sealing and safety of the secondary battery. The second recessed portion 151 recessed into the interior of the secondary battery provided in the lower plastic part 15 can be used to avoid and accommodate the first recessed portion 111, thereby reducing the possibility of interference between the first recessed portion 111 provided on the top cover 11 and other parts. The main body 141 of the seal 14 can be located in the second recessed portion 151 and play a role of sealing and insulation together with the lower plastic part 15, and the seal 14 can also be used to fill the gap between the pole 12 and the second recessed portion 151, while playing a sealing role, it can also reduce the matching accuracy between the pole 12 and the lower plastic part 15.

[0093] In a possible implementation manner, the top patch 2 is sleeved with the pole 12 through a connecting hole, and the distance between the hole wall of the connecting hole and the pole 12 is 0.5 mm to 3 mm.

[0094] The distance between the hole wall and the pole 12 can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, etc.

[0095] The top patch 2 may also be provided with a blasting hole opening and other structures, the top cover 11 may be provided with a QR code for identifying the information of the secondary battery, and the corresponding position of the top patch 2 is also provided with an opening for revealing the QR code. At the same time, the top patch 2 may also be provided with an anti-fool mark for marking whether the pole 12 is a positive pole or a negative pole.

[0096] The overall structure of the secondary battery is as follows Fig. 9 As shown, the top cover assembly 1 is connected to the shell, and a blue film may be provided on the outside of the shell. Fig.10 As shown, in a possible implementation, the top patch 2 may be provided with a third recessed portion 21, and the third recessed portion 21 is recessed in a direction close to the top cover 11. The third recessed portion 21 is provided corresponding to the first recessed portion 111 of the top cover 11, and is in contact with the first recessed portion 111. The fixing member 13 may be provided on a side of the top patch 2 away from the top cover 11, and is located in the third recessed portion 21. This design can increase the contact area between the top patch 2 and the top cover 11, so that the top patch 2 can better cover the top cover 11, thereby improving the protection effect of the top patch 2.

[0097] like Fig.10 As shown, in a possible implementation, the secondary battery may include a heat conductor 9 , and the heat conductor 9 may be disposed around the pole 12 , for example, may be sleeved on the outside of the pole 12 along the circumference of the pole 12 .

[0098] When the secondary battery is in use, the pole 12 usually generates a large amount of heat and the temperature rises quickly. By arranging the heat conductor 9 around the pole 12, the heat generated by the pole 12 can be conducted and transferred away from the pole 12, thereby reducing the possibility of heat accumulation near the pole 12, which is beneficial to reduce the situation of excessively high local temperature of the secondary battery and improve the working stability and safety of the secondary battery.

[0099] like Fig.10 As shown, the heat conductor 9 can be arranged in the third recessed portion 21, that is, the heat conductor 9 can be located on the side of the top patch 2 away from the top cover 11. Such a design can reduce the coverage of the top patch 2 on the heat conductor 9, which is more conducive to the heat conductor 9 transferring heat to the outside of the secondary battery, thereby reducing the possibility of heat accumulation near the pole 12.

[0100] like Fig.11 As shown, in a possible implementation, the heat conductor 9 may be disposed below the top patch 2, so that the top patch 2 can protect the heat conductor 9 and perform an insulating function.

[0101] Based on the secondary batteries involved in the above embodiments, Fig.12 and Fig.13As shown, the embodiment of the present application further provides a battery pack 6, the battery pack 6 includes at least one battery module 7, the battery module 7 includes at least one secondary battery involved in any of the above embodiments, when the battery module 7 includes multiple secondary batteries, each secondary battery can be electrically connected through the bar sheet 5, and the bar sheet 5 can be electrically connected to the pole 12 of the secondary battery by welding or other methods. Since the secondary battery has the above technical effects, the battery pack 6 including the secondary battery also has the corresponding technical effects, which will not be repeated here.

[0102] like Fig.14 As shown, the embodiment of the present application also provides an energy storage box 8, which includes an inverter, a battery management system and at least one battery pack 6. The inverter is used to convert direct current into alternating current. At the same time, the inverter also has the advantages of high conversion efficiency, fast startup speed, high safety, etc., and can also provide functions such as short circuit, overload, over / under voltage and over-temperature protection. The battery management system is used to make the battery pack 6 work within a safe working range, and can control the charging and discharging power of the battery pack according to factors such as ambient temperature, battery status and power demand, etc., to improve the safety of the battery pack 6, make the working state of the battery pack 6 more reasonable, which is conducive to improving the battery life and service life of the battery pack 6.

[0103] The embodiment of the present application provides a secondary battery, a battery pack and an energy storage box. The secondary battery includes an end cap assembly 1 and a top patch 2. The top patch 2 is located on the side of the end cap assembly 1 away from the inside of the secondary battery. The end cap assembly 1 includes a top cover 11 and a pole 12. The pole 12 is mounted on the top cover 11 through a fixing member 13. The top cover 11 is provided with at least one first recessed portion 111. The first recessed portion 111 is recessed toward a side close to the inside of the secondary battery. The bottom wall of the first recessed portion 111 is provided with a mounting hole 111a. The pole 12 is sleeved with the mounting hole 111a. A sealing member 14 is provided along the circumference of the pole 12. The fixing member 13 is located in the first recessed portion 111 and sleeved with the pole 12. One of the fixing member 13 and the pole 12 is provided with a limited recess 121, and the other is provided with a limited protrusion 131. The limiting protrusion 131 extends into the limiting recess 121 along the radial direction of the pole 12. Along the thickness direction of the end cap assembly 1, the pole 12 protrudes from the top patch 2, and the distance between the upper surface of the pole 12 and the upper surface of the top patch 2 is a, 0<a≤2mm. This design can make the structure of the secondary battery more compact, which is conducive to improving the capacity and energy density of the secondary battery.

Claims

1. A secondary battery, characterized in that: The secondary battery includes: An end cap assembly (1), the end cap assembly (1) includes a top cover (11) and a terminal post (12), and the terminal post (12) is installed on the top cover (11) through a fixing member (13); A top patch (2), the top patch (2) is located on the side of the top cover (11) away from the inside of the secondary battery; Wherein, the top cover (11) is provided with at least one first recess (111), the first recess (111) is recessed toward the side close to the inside of the secondary battery, the bottom wall of the first recess (111) is provided with a mounting hole (111a), at least part of the terminal post (12) is sleeved with the mounting hole (111a), a sealing member (14) is arranged along the circumferential direction of the terminal post (12), the fixing member (13) is located in the first recess (111) and is sleeved with the terminal post (12), one of the fixing member (13) and the terminal post (12) is provided with a limiting recess (121), the other is provided with a limiting protrusion (131), and at least part of the limiting protrusion (131) extends radially into the limiting recess (121) along the terminal post (12). Along the thickness direction of the end cap assembly (1), the terminal post (12) protrudes from the top patch (2), and the distance between the upper surface of the terminal post (12) and the upper surface of the top patch (2) is a, and 0 < a ≤ 2 mm.

2. The secondary battery according to claim 1, characterized in that: Along the thickness direction of the end cap assembly (1), the distance between the upper surface of the terminal post (12) and the upper surface of the top cover (11) is b, and 0.5 mm ≤ b ≤ 3 mm.

3. The secondary battery according to claim 1, characterized in that: The secondary battery further includes a connecting member (3) and a battery cell assembly (4), the battery cell assembly (4) includes electrode tabs, and the terminal post (12) is electrically connected to the electrode tabs through the connecting member (3); The connecting member (3) is provided with a connecting groove (311), the connecting groove (311) is recessed along the direction away from the end cap assembly (1), the terminal post (12) extends into the connecting groove (311) along the thickness direction of the end cap assembly (1) and is connected to the inner wall of the connecting groove (311).

4. The secondary battery according to claim 3, characterized in that: The battery cell assembly (4) includes a first battery cell (41) and a second battery cell (42), the first battery cell (41) has a first electrode tab (411), the second battery cell (42) has a second electrode tab (412), the connecting member (3) includes a terminal post connecting portion (31), a first electrode tab connecting portion (32) and a second electrode tab connecting portion (33), the first electrode tab connecting portion (32) is electrically connected to the first electrode tab (411), and the second electrode tab connecting portion (33) is electrically connected to the second electrode tab (412); Along the width direction of the end cover assembly (1), the first pole lug connection portion (32) and the second pole lug connection portion (33) are located on opposite sides of the pole connection portion (31), and the connection groove (311) is provided on a side of the pole connection portion (31) facing the pole (12), and the side of the pole connection portion (31) facing the battery cell assembly (4) is protruded at a position corresponding to the connection groove (311).

5. The secondary battery according to claim 3, characterized in that: Along the thickness direction of the end cover assembly (1), the depth of the connection groove (311) is 1 mm to 6 mm.

6. The secondary battery according to any one of claims 1 to 5, characterized in that: The first recessed portion (111) is a stepped groove, and the side of the fixing member (13) facing the side wall of the first recessed portion (111) is a stepped surface, and the stepped surface is in contact with the side wall of the stepped groove.

7. The secondary battery according to any one of claims 1 to 5, characterized in that: The sealing member (14) comprises a main body portion (141) and a second extension portion (142) which are connected to each other, the cross-sectional area of ​​the main body portion (141) being larger than the cross-sectional area of ​​the second extension portion (142), the main body portion (141) being located on a side of the top cover (11) close to the interior of the secondary battery, the second extension portion (142) extending in a direction close to the top patch (2) and being arranged along the circumference of the pole (12), at least a portion of the second extension portion (142) extending into the mounting hole (111a) and being located between the pole (12) and the hole wall of the mounting hole (111a).

8. The secondary battery according to any one of claims 1 to 5, characterized in that: The end cover assembly (1) comprises a lower plastic part (15), the lower plastic part (15) is located on a side of the top cover (11) facing the interior of the secondary battery, and is sleeved on the pole (12); The lower plastic part (15) has a second recessed portion (151), the second recessed portion (151) being recessed in a direction away from the top cover (11) and being used to accommodate the first recessed portion (111); The lower plastic part (15) is sleeved with the pole (12) via the second recessed portion (151); the sealing member (14) is arranged along the circumference of the pole (12) and is located between the side wall of the pole (12) and the second recessed portion (151).

9. A battery pack, characterized in that: The battery pack (6) comprises at least one battery module (7), and the battery module (7) comprises at least one secondary battery; The secondary battery is the secondary battery according to any one of claims 1 to 8.

10. An energy storage box, characterized in that: The energy storage box (8) comprises an inverter, a battery management system and at least one battery pack (6), wherein the battery pack (6) is the battery pack (6) according to claim 9.

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