Battery top cover and battery

Abstract

The invention belongs to the technical field of batteries, and discloses a battery top cover and a battery. The battery top cover can package the electrode assembly in a shell of the battery, the battery top cover comprises a top cover piece, a welding part is arranged on the top cover piece, a through hole is formed in at least one side of the welding part in a penetrating manner, a tab of the electrode assembly can extend out of the through hole and is laid on the welding part, and the welding part is used for being welded with the tab. Compared with a traditional battery top cover, the battery top cover has the advantages that a connecting piece is omitted, the step of welding the tabs and the connecting piece is reduced, and the step of welding the connecting piece and the top cover piece is also reduced, so that the battery structure is simplified, and the production cost is reduced. In the height direction of the battery, the electrode assembly can occupy the height of a connecting piece of a traditional battery and replace a bent part of a positive tab group in the traditional battery, so that the height of the electrode assembly is higher, the size of the electrode assembly in the height direction is greatly increased, and the energy density and the space utilization rate of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery top cover and a battery. Background Art

[0002] With the development of new energy technology, batteries have been widely used due to their efficient energy storage capacity. At present, the battery mainly includes a battery shell, a battery top cover and an electrode assembly arranged in the battery shell, the electrode assembly is provided with a pole ear, the battery top cover is arranged above the electrode assembly, and the battery top cover is provided with a pole column, which can be welded and fixed with the pole ear, thereby guiding the current of the electrode assembly to the pole column, which is convenient for the subsequent charging and discharging of the electrode assembly.

[0003] In the prior art, in order to ensure the welding effect of the pole lug and the pole column, a connecting piece needs to be arranged between the pole column and the pole lug, and the pole lug is connected to the connecting piece and then connected to the pole column to draw out the current. However, since the height for installing the connecting piece needs to be reserved in the battery housing, the axial space of the battery is wasted, thereby reducing the energy density of the battery. Summary of the invention

[0004] The object of the present invention is to provide a battery top cover and a battery, which can improve the utilization rate of the axial space of the battery, thereby increasing the energy density of the battery and reducing the use cost of the battery.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] The battery top cover is used to encapsulate the electrode assembly in the housing, and the battery top cover includes:

[0007] A top cover sheet is provided with a welding portion, and a through hole is provided through at least one side of the welding portion, and the electrode tab of the electrode assembly can extend from the through hole and be laid on the welding portion, and the welding portion is used for welding with the electrode tab.

[0008] Preferably, along the axial direction of the top cover sheet, the middle portion of the welding portion is recessed toward the direction close to the pole ear, so that the welding portion forms a sunken platform structure.

[0009] Preferably, the via holes are provided on both sides of the welding portion, and the tab can pass through the two via holes and be laid on the welding portion.

[0010] Preferably, a width W between a side wall of the welding portion and an inner side wall of the via hole away from the welding portion satisfies: W≥n×d, wherein n is the number of the tabs passing through the via hole, and d is the width of the tabs.

[0011] Preferably, the horizontal cross-sectional area S of the welding portion satisfies: S≥A / Z, wherein A is the set maximum flow rate of the battery, and Z is the current carrying coefficient of the positive electrode sheet or the negative electrode sheet in the electrode assembly.

[0012] Preferably, the battery top cover also includes a sealing assembly, which is fixedly connected to the top cover sheet, and the sealing cover is arranged on the through hole and the welding portion; the top cover sheet is also provided with an annular groove, the through hole is opened at the bottom of the annular groove, and the annular groove is used to limit and accommodate the sealing assembly so that the top surface of the sealing assembly is flush with the top surface of the top cover sheet.

[0013] Preferably, the battery top cover further comprises a closing structure, wherein the closing structure is located at the connection between the pole lug and the welding portion and is located at a side of the pole lug away from the welding portion.

[0014] Preferably, the sealing assembly comprises a sealing cover and a sealing ring, the sealing cover is limitedly accommodated in the annular groove and is flush with the top surface of the top cover sheet, and the sealing ring is sandwiched between the closing structure and the sealing cover.

[0015] A battery, comprising the above-mentioned battery top cover.

[0016] Preferably, the housing comprises a first shell, a second shell and an insulating portion, one end of the first shell is connected to one end of the second shell through the insulating portion, and the other end of the first shell and the other end of the second shell are both sealed with the battery top cover;

[0017] The tabs of the electrode assembly include a positive tab group and a negative tab group. The positive tab group is inserted through the through hole of the battery top cover on the first shell and welded to the welding part of the battery top cover. The negative tab group is inserted through the through hole of the battery top cover on the second shell and welded to the welding part of the battery top cover.

[0018] The battery top cover and battery provided by the present invention have the following beneficial effects: Compared with the traditional battery top cover, the battery top cover omits the connecting sheet, reduces the steps of welding the pole ear to the connecting sheet, and also reduces the steps of welding the connecting sheet to the top cover sheet, thereby simplifying the battery structure and reducing the production cost. In the height direction of the battery, since the setting of the connecting sheet is omitted, the electrode assembly can occupy the height of the connecting sheet of the traditional battery, thereby greatly increasing the size of the electrode assembly in the height direction and improving the energy density of the battery. In addition, since the pole ear is directly welded to the welding part, the bending direction of the pole ear after passing through the through hole is horizontal and will not occupy the space in the height direction of the battery. Therefore, the electrode assembly can replace the bent part of the positive pole ear group in the traditional battery, thereby making the height of the electrode assembly higher, thereby improving the space utilization of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the internal structure of a battery provided by the prior art;

[0020] Figure 2 It is a schematic diagram of the connection between the electrode assembly and the connecting sheet provided by the prior art;

[0021] Figure 3 is a schematic diagram of the internal structure of a battery provided by an embodiment of the present invention;

[0022] Figure 4 is a top view of a top cover sheet connected to a positive electrode tab group provided in an embodiment of the present invention;

[0023] Figure 5 is a schematic diagram of the connection between the electrode assembly and the welding part provided in an embodiment of the present invention;

[0024] Figure 6 is a schematic structural diagram of a top cover sheet provided by an embodiment of the present invention;

[0025] Figure 7 is a top view of a top cover sheet connected to a negative electrode lug group provided by an embodiment of the present invention;

[0026] Figure 8 It is a schematic diagram of the structure of a housing provided by an embodiment of the present invention.

[0027] In the figure:

[0028] 100, housing; 110, first housing; 120, second housing; 130, insulating portion; 200, electrode assembly; 300, tab; 310, positive tab group; 320, negative tab group; 410, positive pole column; 420, negative pole column; 500, connecting piece; 600, battery top cover;

[0029] 1. Top cover; 11. Welding part; 12. Through hole; 13. Annular groove; 14. Liquid injection hole; 15. Explosion-proof valve;

[0030] 2. Closed structure;

[0031] 3. Sealing assembly; 31. Sealing cover; 32. Sealing ring. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "right", "left" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] refer to Figure 1 , Figure 2 As shown, the existing battery structure is described by taking the output of positive and negative electrodes from both sides of the battery as an example, generally including a shell 100, an electrode assembly 200, a pole, two connecting pieces 500 and two battery top covers 600, wherein the two battery top covers 600 are covered at the openings at both ends of the shell 100, the pole tabs 300 are arranged at both ends of the electrode assembly 200, and the two connecting pieces 500 are respectively arranged between the pole tabs 300 and the two battery top covers 600, and the pole tabs include a positive pole 410 and a negative pole 420, and the positive pole 410 and the negative pole 420 are respectively arranged on the two battery top covers 600, and the pole tab 300 is connected to the connecting piece 500, and then connected to the positive pole 410 and the negative pole 420, so that the current can be drawn. That is, the pole tab 300 is connected to the positive pole 410 and the negative pole 420 through the connecting piece 500, and then the electrode assembly 200 and the connecting piece 500 are encapsulated in the shell 100. However, since a height for installing the connecting piece 500 needs to be reserved in the housing 100, the axial space of the battery is wasted, thereby reducing the energy density of the battery.

[0037] Based on this, the present embodiment provides a battery top cover 600, which can omit the connecting piece 500 and directly connect to the tab 300, thereby reducing the setting of the connecting piece 500 and eliminating the axial reserved space in the housing 100, thereby improving the axial space utilization of the battery, and further improving the battery energy density. In addition, by eliminating the setting of the connecting piece 500, the positioning, welding and other processes of the connecting piece 500 during the battery assembly process can also be simplified, thereby improving the production efficiency of the battery and reducing the manufacturing cost.

[0038] Combination Figures 3 to 8 In one embodiment of the present invention, a battery cover 600 is provided. Taking a battery with tabs at both ends as an example, the battery cover 600 is provided at the openings at both ends of the housing 100. The battery may be a square battery, a cylindrical battery or a blade battery, which is not limited in this embodiment. The battery includes a housing 100, a battery cover 600 and an electrode assembly 200 disposed in the housing 100. The electrode assembly 200 has tabs 300 at both ends. In this embodiment, the reference Figure 3 As shown, the tab 300 at the top of the battery is set as a positive tab group 310, and the tab 300 at the bottom of the battery is set as a negative tab group 320. A battery top cover 600 is provided at each end of the housing 100, one of the battery top covers 600 can be connected to the positive tab group 310, and the other battery top cover 600 can be connected to the negative tab group 320, and the electrode assembly 200 is encapsulated in the housing 100 through the two battery top covers 600, thereby completing the current output and installation of the battery. In this way, it is possible to achieve a setting without setting the connecting piece 500 in the housing 100.

[0039] Specifically, in this embodiment, the battery top cover 600 includes a top cover sheet 1, a welding portion 11 is provided on the top cover sheet 1, and a through hole 12 is provided through at least one side of the welding portion 11. It should be noted that the structures of the two battery top covers 600 located at both ends of the housing 100 are the same, so the battery top cover 600 connected to the positive electrode tab group 310 will be taken as an example for specific description.

[0040] refer to Figure 3 , Figure 4As shown, the positive electrode ear group 310 can extend from the through hole 12 and be laid on the upper surface of the welding portion 11, and the welding portion 11 can be welded to the positive electrode ear group 310, so that the positive electrode ear group 310 is fixedly electrically connected to the top cover sheet 1. Compared with the conventional battery top cover 600, the present embodiment omits the connecting sheet 500, reduces the steps of welding the positive electrode ear group 310 and the negative electrode ear group 320 to the connecting sheet 500 respectively, and also reduces the steps of welding the connecting sheet 500 and the top cover sheet 1, thereby simplifying the battery structure and reducing production costs. In the height direction of the battery, the electrode assembly 200 provided in the present embodiment can occupy the height of the connecting sheet 500 of the conventional battery, thereby greatly increasing the size of the electrode assembly 200 in the height direction and improving the energy density of the battery. On the other hand, from Figure 5 It can be seen that the positive electrode tab group 310 of this embodiment is directly welded to the welding portion 11. After the positive electrode tab group 310 passes through the through hole 12, the bending direction is horizontal and does not occupy the space in the height direction of the battery. Figure 2 As shown, the positive electrode tab group 310 in a traditional battery will be bent after being welded to the connecting sheet 500, and will also occupy a portion of the height space of the battery. The electrode assembly 200 provided in this embodiment can occupy the bent portion of the positive electrode tab group 310 in the traditional battery, thereby making the height of the electrode assembly 200 higher and the space utilization rate of the battery higher.

[0041] Furthermore, it should be noted that the reference Figure 5 As shown, the positive electrode tab group 310 of the electrode assembly 200 passes through the through hole 12 and is welded to the upper surface of the welding portion 11. After welding, the redundant part of the positive electrode tab group 310 is located on the side of the welding portion 11 and moves in the lateral direction. Figure 2 ), a certain amount of space needs to be reserved between the top of the electrode assembly 200 and the connecting sheet 500 to allow the positive electrode ear group 310 to be folded in an S shape. This part of the space is used for the redundant part of the positive electrode ear group 310 to move, but it is difficult to reserve this part of the space. If the reserved space is small, it is easy to cause the positive electrode ear group 310 to be inserted upside down, causing a short circuit in the battery. If the reserved space is large, it is easy to waste the height space in the battery, thereby reducing the energy density of the battery. The redundant part of the positive electrode ear group 310 after welding provided in this embodiment is located on the side of the welding part 11, which changes the movement direction of the redundant part of the positive electrode ear group 310. Therefore, it is only necessary to reserve active space for the redundant part of the positive electrode ear group 310 in the lateral direction, which not only avoids reserving space between the electrode assembly 200 and the top cover sheet 1, but also prevents the positive electrode ear group 310 from being inserted upside down, thereby achieving an increase in the energy density of the battery and ensuring the safety and reliability of use.

[0042] Alternatively, if Figure 6As shown, after the positive electrode ear group 310 is welded on the welding portion 11, a closed structure 2 is further provided at the connection between the positive electrode ear group 310 and the welding portion 11, and the closed structure 2 is located on the side of the positive electrode ear group 310 away from the welding portion 11 to protect the connection between the two and prevent interference from the external environment. Exemplarily, in this embodiment, the closed structure 2 uses a polyimide PI tape, which is laid at the connection between the positive electrode ear group 310 and the welding portion 11, and is located on the side of the positive electrode ear group 310 away from the welding portion 11 to isolate it. In other parallel embodiments, the closed structure 2 may also be a high temperature resistant rubber, such as silicone rubber, fluororubber, butyl rubber or perfluoroether rubber, etc.; it may also be a high temperature resistant plastic, such as polyphenylene sulfide PPS, polyetheretherketone PEEK, polyaryletherketone PAEK, polysulfone PSU, polyarylate, polybenzimidazole, high temperature nylon PA46, high temperature nylon PPA, polytetrafluoroethylene, etc. After melting the high temperature resistant rubber or plastic, the connection between the positive electrode ear group 310 and the welding portion 11 can be protected. Preferably, in this embodiment, the high temperature resistance requirement of the closed structure 2 is 150-500°C.

[0043] In this embodiment, refer to Figure 6 , along the axial direction of the top cover sheet 1, the middle part of the welding part 11 is recessed in the direction close to the positive ear group 310, so that the welding part 11 forms a sunken platform structure. Since the top cover sheet 1 is relatively thin, if the welding part 11 is designed as a flat plate structure, the thickness of the welding part 11 will also be thin, which is not conducive to the overcurrent strength. After the welding part 11 is designed as a sunken platform structure, the thickness of the welding part 11 can be increased accordingly, which will not only not protrude from the top cover sheet 1, thus ensuring safety and aesthetics, but also effectively increase the overcurrent area, thereby helping to improve the performance of the battery. By way of example, in this embodiment, the sinking height of the welding part 11 (i.e., the distance between the lowest point of the welding part 11 and the upper surface of the top cover sheet 1) is 0.1-2mm.

[0044] Furthermore, vias 12 are provided on both sides of the welding portion 11, so that the positive electrode tab group 310 can be divided into two parts and each part passes through a via 12 and is laid on the welding portion 11. This can effectively reduce the thickness of the positive electrode tab group 310 during welding, thereby facilitating welding and ensuring welding quality and reliability.

[0045] In this embodiment, if Figure 4As shown, the width between the side wall of the welding portion 11 and the inner side wall of the via 12 away from the welding portion 11 is set to W, and W needs to satisfy the following relationship: W≥n×d, where n is the number of positive tabs 300 in the positive tab group 310 passing through the via 12, and d is the width of each positive tab 300. For example, if the width of the positive tab 300 is 5μm, and the number of positive tabs 300 passing through the via 12 is 25, then W needs to be no less than 0.125mm. Therefore, it can be ensured that the positive tab group 310 can completely pass through the via 12, reducing the operating pressure.

[0046] In addition, the welding portion 11 also needs to have sufficient width to meet the current requirements of the electrode assembly 200. In this embodiment, the horizontal cross-sectional area of ​​the welding portion 11 is set to S, and S needs to satisfy the following relationship: S ≥ A / Z, where A is the set maximum current flow of the battery, and Z is the current carrying coefficient of the positive electrode sheet. For example, for a 100A battery, the maximum current flow is 2c, and the current carrying coefficient of the positive electrode sheet (aluminum sheet) is 5, then the horizontal cross-sectional area of ​​the welding portion 11 needs to be at least 40mm 2 Therefore, by increasing the horizontal cross-sectional area of ​​the welding portion 11 , the width of the welding portion 11 can be increased, thereby ensuring the purpose of the overcurrent requirement of the electrode assembly 200 .

[0047] Specifically, in this embodiment, Figure 6 As shown, the battery top cover 600 also includes a sealing component 3, which is fixedly connected to the top cover sheet 1, and the sealing cover is arranged on the through hole 12 and the welding part 11 to ensure the safety of the positive electrode ear group 310 or the negative electrode ear group 320 to avoid interference from the outside.

[0048] In addition, Figure 6 As shown, an annular groove 13 is also provided on the top cover sheet 1, and the above-mentioned through hole 12 is opened at the bottom of the annular groove 13. The annular groove 13 is used to limit the installation of the sealing component 3 so that the sealing component 3 is hidden in the annular groove 13 to avoid protruding from the top cover sheet 1, thereby ensuring the safety of the battery top cover 600.

[0049] refer to Figure 6 As shown, one implementation of this embodiment is that the sealing assembly 3 includes a sealing cover 31 and a sealing ring 32, wherein the sealing cover 31 is limitedly accommodated in the annular groove 13 and is flush with the top surface of the top cover sheet 1, and the sealing cover 31 is sealingly arranged in the through hole 12 and the welding portion 11 to isolate and insulate the positive electrode ear group 310 from the external environment; the sealing ring 32 is clamped between the closing structure 2 and the sealing cover 31 to seal the joint between the closing structure 2 and the sealing cover 31, thereby ensuring the airtightness of the battery, preventing external pollutants or moisture from entering the battery, and also ensuring that the electrolyte inside the battery will not leak to the outside, preventing risks such as battery failure.

[0050] Optionally, in this embodiment, if Figure 4 and Figure 7 As shown, the top cover sheet 1 is also provided with a liquid injection hole 14 and an explosion-proof valve 15. The liquid injection hole 14 is connected to the electrode assembly 200 so that the liquid injection device can inject electrolyte into the electrode assembly 200 through the liquid injection hole 14. The explosion-proof valve 15 is provided with an explosion-proof notch so that when the air pressure or temperature in the housing 100 exceeds a certain value, the explosion-proof notch can burst open immediately, so that the internal high temperature air pressure can be released to the outside to avoid battery explosion. It should be noted that in this embodiment, combined with Figure 5 , Figure 8 As shown, one of the top cover sheets 1 is provided with only the injection hole 14, and the other top cover sheet 1 is provided with only the explosion-proof valve 15, so that the explosion-proof valve 15 and the injection hole 14 can be assembled through the two top cover sheets 1 in the limited space of the top cover sheet 1, thereby ensuring the safe use performance of the battery.

[0051] The present embodiment also provides a battery, including an outer shell 100, an electrode assembly 200 and a battery top cover 600, wherein the battery top cover 600 includes a top cover sheet 1, a welding portion 11 is provided on the top cover sheet 1, and a through hole 12 is provided through at least one side of the welding portion 11, the electrode assembly 200 is arranged in the outer shell 100, the pole ear 300 of the electrode assembly 200 is passed through the through hole 12 and laid on the welding portion 11, and the welding portion 11 is connected to the pole ear 300 by means of welding, thereby realizing the connection between the pole ear 300 and the battery top cover 600 while packaging the battery.

[0052] Since the battery includes the battery top cover 600 described in the above embodiment, the battery in this embodiment has the effect of the battery top cover 600 described in the above embodiment, that is, in this battery, since the pole ear 300 is directly connected to the top cover sheet 1 of the battery top cover 600, the setting of the connecting sheet 500 can be omitted, and the height of the electrode assembly 200 is increased, thereby increasing the energy density of the battery, while simplifying the internal structure, improving the production efficiency, and reducing the production cost.

[0053] It is worth noting that since the pole ear 300 is directly connected to the top cover sheet 1, the top cover sheet 1 also has a conductive effect. At this time, for the entire battery, the top cover sheet 1 can be electrically conductive to the outside, thereby eliminating the need for the poles (including the positive pole 410 and the negative pole 420) in the traditional battery. Through the above-mentioned arrangement, the height space occupied by the battery can be reduced in the height direction of the battery. On the one hand, the battery can be used in an environment with a narrower space, expanding the application scenarios of the battery; on the other hand, for a battery with a constant total height, the height of the electrode assembly 200 can be correspondingly increased to fill the space reserved when the pole is not set by the electrode assembly 200, thereby further increasing the energy density of the entire battery and further increasing the battery's use efficiency. When the top cover sheet 1 is conductive, the traditional shell 100 will not be applicable to this battery. In order to realize the charging and discharging function of the battery, in this embodiment, the structure of the shell 100 is improved.

[0054] Specifically, refer to Figure 8 As shown, the housing 100 includes a first housing 110, a second housing 120 and an insulating portion 130, wherein one end of the first housing 110 is connected to one end of the second housing 120 through the insulating portion 130, and the other end of the first housing 110 and the other end of the second housing 120 are both sealed with a battery top cover 600. One implementation of this embodiment is that the positive electrode ear group 310 of the electrode assembly 200 is arranged at the other end of the first housing 110, and the positive electrode ear group 310 passes through the through hole 12 of the battery top cover 600 on the first housing 110 and is connected to the welding portion 11 on the first housing 110, so that the first housing 110 has the function of deriving a positive current. The negative electrode ear group 320 of the electrode assembly 200 is arranged at the other end of the second housing 120, and the negative electrode ear group 320 passes through the through hole 12 of the battery top cover 600 on the second housing 120 and is connected to the welding portion 11 on the second housing 120, so that the second housing 120 has the function of deriving a negative current. The insulating portion 130 is used to electrically insulate the first shell 110 and the second shell 120 , similar to the role of the diaphragm in the electrode assembly 200 , thereby preventing the first shell 110 and the second shell 120 from short-circuiting and ensuring the battery's functionality.

[0055] Preferably, the insulating portion 130 is made of high temperature and corrosion resistant rubber or plastic, and the first shell 110 , the second shell 120 and the top cover sheet 1 can be made of aluminum, stainless steel or plastic, which is not limited in this embodiment.

[0056] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means 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 representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Battery top cover, characterized in that, The battery top cover (600) is used to encapsulate the electrode assembly (200) in the housing (100), and the battery top cover (600) comprises: A top cover sheet (1), wherein a welding portion (11) is provided on the top cover sheet (1), and a through hole (12) is provided through at least one side of the welding portion (11); a pole ear (300) of the electrode assembly (200) can extend from the through hole (12) and be laid on the welding portion (11); and the welding portion (11) is used for welding with the pole ear (300).

2. The battery top cover according to claim 1, characterized in that: Along the axial direction of the top cover sheet (1), the middle portion of the welding portion (11) is recessed in a direction close to the pole lug (300), so that the welding portion (11) forms a sunken platform structure.

3. The battery top cover according to claim 1, characterized in that: The via holes (12) are provided on both sides of the welding portion (11), and the tab (300) can pass through the two via holes (12) and be laid on the welding portion (11).

4. The battery top cover according to claim 1, characterized in that: The width W between the side wall of the welding portion (11) and the inner side wall of the via hole (12) away from the welding portion (11) satisfies: W≥n×d, wherein n is the number of the pole tabs (300) passing through the via hole (12), and d is the width of the pole tab (300).

5. The battery top cover according to claim 1, characterized in that: The horizontal cross-sectional area S of the welding portion (11) satisfies: S≥A / Z, wherein A is the set maximum flow rate of the battery, and Z is the current carrying coefficient of the positive electrode sheet or the negative electrode sheet in the electrode assembly (200).

6. The battery top cover according to claim 1, characterized in that: The battery top cover (600) further comprises a sealing component (3), wherein the sealing component (3) is fixedly connected to the top cover sheet (1), and a sealing cover is arranged on the via hole (12) and the welding portion (11); The top cover sheet (1) is also provided with an annular groove (13), the bottom of which is provided with the through hole (12), and the annular groove (13) is used to limit the position of the sealing component (3) so that the top surface of the sealing component (3) is flush with the top surface of the top cover sheet (1).

7. The battery top cover according to claim 6, characterized in that: The battery top cover (600) further comprises a closed structure (2), wherein the closed structure (2) is located at the connection between the pole lug (300) and the welding portion (11), and is located on a side of the pole lug (300) away from the welding portion (11).

8. The battery top cover according to claim 7, characterized in that: The sealing assembly (3) comprises a sealing cover (31) and a sealing ring (32); the sealing cover (31) is limitedly accommodated in the annular groove (13) and is flush with the top surface of the top cover sheet (1); and the sealing ring (32) is sandwiched between the closed structure (2) and the sealing cover (31).

9. A battery, characterized in that A battery top cover (600) comprising any one of claims 1-8.

10. The battery according to claim 9, characterized in that The housing (100) comprises a first shell (110), a second shell (120) and an insulating portion (130); one end of the first shell (110) is connected to one end of the second shell (120) via the insulating portion (130); the other ends of the first shell (110) and the second shell (120) are both sealed with the battery top cover (600); The tabs (300) of the electrode assembly (200) include a positive tab group (310) and a negative tab group (320); the positive tab group (310) is inserted through a through hole (12) of the battery top cover (600) located on the first shell (110) and is welded to a welding portion (11) of the battery top cover (600); and the negative tab group (320) is inserted through a through hole (12) of the battery top cover (600) located on the second shell (120) and is welded to a welding portion (11) of the battery top cover (600).

Images