Secondary battery cover plate and battery

Abstract

The utility model provides a secondary battery cover plate and a battery, and relates to the technical field of batteries. The secondary battery cover plate comprises a connecting sheet and a lower plastic which are laminated along a first direction. In the first direction, the connecting piece is provided with a first surface facing the lower plastic, and the lower plastic is provided with a second surface facing the connecting piece. A first limiting part is arranged on the first surface, a second limiting part is arranged on the second surface, and the first limiting part is matched with the second limiting part so as to limit the connecting piece. Therefore, the possibility that the connecting piece moves due to the problems of battery shaking, tab deformation and the like can be reduced, and the connecting piece is positioned at a normal position, so that the fusing part can normally play a fusing role, the possibility that the fusing part loses action and causes thermal runaway of the battery can be reduced, and the use reliability of the battery is improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a secondary battery cover plate and a battery. Background Art

[0002] A battery is one of the power sources of electrical equipment. With the popularization and application of batteries in multiple fields, the safety issue of batteries has also become an important problem in battery use.

[0003] A battery usually includes a connecting piece for realizing the electrical connection between the tab and the terminal post. A fusing part is arranged in the middle of the connecting piece. When the battery is used abnormally, the fusing part can be fused to cut off the circuit where the battery is located, protecting the safety of users and electrical equipment.

[0004] However, in the related art, the connection method of the connecting piece is improper, resulting in that the fusing part is likely to lose its function and even cause thermal runaway of the battery. Summary of the Utility Model

[0005] The present application provides a secondary battery cover plate and a battery, which can reduce the possibility that the fusing part loses its function and even causes thermal runaway of the battery.

[0006] In a first aspect, the present application provides a secondary battery cover plate, including a connecting piece and a lower plastic layer stacked in a first direction. In the first direction, the connecting piece has a first surface facing the lower plastic, and the lower plastic has a second surface facing the connecting piece. A first limiting part is arranged on the first surface, and a second limiting part is arranged on the second surface. The first limiting part and the second limiting part cooperate to limit the connecting piece.

[0007] In the embodiment of the present application, since the first surface faces the lower plastic and the second surface faces the connecting piece, the first surface and the second surface are opposite. Thus, the first limiting part and the second limiting part are also opposite, and the two can cooperate to limit the connecting piece.

[0008] In this way, during the subsequent assembly of the battery or the actual application process of the battery, the possibility that the connecting piece moves due to problems such as battery shaking and tab deformation can be reduced, preventing the connecting piece from shifting. Thereby, the connecting piece can be in a normal position, and further, the possibility that the fusing part loses its function and even causes thermal runaway of the battery can be reduced.

[0009] Optionally, a limiting hole is arranged on the first surface, the limiting hole forms the first limiting part, a limiting boss is arranged on the second surface, and the limiting boss forms the second limiting part. The limiting boss is snap-fitted into the limiting hole.

[0010] Through the above arrangement, the limiting boss can be snapped into the limiting hole, so that the limiting boss can limit the movement of the connecting piece through the hole wall of the limiting hole, so that the connecting piece can be kept in a normal position, reducing the possibility of the fuse part losing its function or even causing thermal runaway of the battery.

[0011] Optionally, the limiting hole passes through the connecting piece along the first direction, the limiting boss is embedded in the limiting hole, and a side of the limiting boss facing away from the second surface is located in the limiting hole.

[0012] Through the above arrangement, the possibility of the problem that the limiting boss extends from the connecting piece and affects the arrangement of other components in the battery can be reduced.

[0013] Optionally, there are multiple limiting bosses and multiple limiting holes, and the multiple limiting bosses are clamped in the limiting holes in a one-to-one correspondence.

[0014] In this way, a plurality of limiting bosses can be snapped into a plurality of limiting holes to limit the connecting piece at a plurality of positions, so that the first limiting portion and the second limiting portion have a better limiting effect on the connecting piece.

[0015] Optionally, the connecting piece includes a pole connection portion, a fuse portion and a pole lug connection portion arranged along the second direction, and the fuse portion is connected between the pole connection portion and the pole lug connection portion. A limiting hole is provided on the surface of at least one of the fuse portion, the pole lug connection portion and the pole connection portion facing the lower plastic. The first direction is perpendicular to the second direction.

[0016] Since the fuse is located between the pole connecting portion and the pole lug connecting portion, after the connecting piece connects the pole lug and the pole, the fuse is located between the pole lug and the pole, so that the fuse can be normally melted to cut off the circuit.

[0017] Thus, the limiting hole can also be arranged in a variety of ways, that is, the limiting hole can be arranged on at least one of the fuse part, the pole lug connection part and the pole connection part.

[0018] Optionally, the flow conducting area of the fuse part is S1, the flow conducting area of the pole lug connection part is S2, and the flow conducting area of the pole connection part is S3. S1, S2 and S3 satisfy: S1<2×S2, and S1<S3.

[0019] Wherein, S1 is the projection area of the fuse part in the second direction, S2 is the projection area of the tab connection part in the third direction, and S3 is the projection area of the pole connection part in the second direction. Both the first direction and the second direction are perpendicular to the third direction.

[0020] Through the above settings, the diversion area of the fusing part can be made smaller than the diversion areas of the remaining parts of the tab connection part excluding the limiting holes and the remaining parts of the pole connection part excluding the limiting holes, so that the fusing part can fuse prior to the tab connection part and the pole connection part, playing a protective role.

[0021] Optionally, a limiting protrusion is provided on the first surface, and the limiting protrusion forms a first limiting portion. A limiting groove is provided on the second surface, and the limiting groove forms a second limiting portion. The limiting protrusion is embedded in the limiting groove.

[0022] Through the above settings, the limiting protrusion can be embedded in the limiting groove, so that the limiting groove can restrict the movement of the limiting protrusion through its groove walls, thereby restricting the movement of the connecting piece, enabling the connecting piece to remain in the normal position, reducing the possibility that the fusing part loses its function or even causes thermal runaway of the battery.

[0023] Optionally, a mounting boss is provided on the second surface, and the limiting groove is provided on the mounting boss.

[0024] In this way, the limiting groove can be provided on the mounting boss, facilitating the formation of the limiting groove and also reducing the possibility of problems such as the failure of the lower plastic insulation caused by the setting of the limiting groove.

[0025] Optionally, a limiting block is further provided on the second surface. The connecting piece has a third surface opposite to the first surface, and there is a contact surface between the first surface and the third surface. The contact surface abuts against the limiting block to limit the connecting piece.

[0026] In this way, the contact surface abuts against the limiting block, which can also limit the connecting piece and reduce the possibility of the connecting piece moving.

[0027] In a second aspect, the present application provides a battery, including any one of the secondary battery covers in the above first aspect.

[0028] For what is provided in the above second aspect and each possible design of the above second aspect, the beneficial effects can refer to the beneficial effects brought by the above first aspect and each possible implementation manner of the first aspect, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of a secondary battery cover according to an embodiment of the present application.

[0030] Figure 2 It is a schematic diagram of the cooperation between a secondary battery cover and an electric core according to an embodiment of the present application.

[0031] Figure 3 It is Figure 1 The sectional view taken along line A-A in

[0032] Figure 4 is Figure 3 The partial enlarged view at position B in

[0033] Figure 5 The exploded view of a secondary battery cover plate according to an embodiment of the present application.

[0034] Figure 6 The schematic diagram of a connecting piece according to an embodiment of the present application.

[0035] Figure 7 The partial schematic diagram of a lower plastic according to an embodiment of the present application.

[0036] Explanation of reference numerals:

[0037] 100: Secondary battery cover plate; 10: Connecting piece; 20: Lower plastic; 11: First surface; 21: Second surface; 12: Third surface; 30: First limiting portion; 40: Second limiting portion; 31: Limiting hole; 41: Limiting boss; 101: Pole connection portion; 102: Fusing portion; 103: Tab connection portion; 50: Limiting block; 60: Contact surface; 200: Electric core; 201: Tab; 300: Pole; X: First direction; Y: Second direction; Z: Third direction. Detailed implementation manners

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusion.

[0040] Reference to "embodiment" herein means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0041] As used herein, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: the existence of A, the coexistence of A and B, and the existence of B. Additionally, the character " / " in this text generally indicates an "or" relationship between the associated objects before and after.

[0042] The directional terms used in the following description are all the directions shown in the figures, and do not limit the specific structure of the current-limiting module of the present application. For example, in the description of the present application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application.

[0043] In addition, the terms "first", "second", etc. in the description, claims or the above-mentioned drawings of the present application are used to distinguish different objects, rather than to describe a specific order, and may explicitly or implicitly include one or more of such features.

[0044] In the description of the present application, unless otherwise specified, the meaning of "a plurality" refers to more than two (including two). Similarly, "a plurality of groups" refers to more than two groups (including two groups).

[0045] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, the "connection" or "coupling" of a mechanical structure may refer to a physical connection. For example, a physical connection may be a fixed connection, such as a fixed connection through a spacer, such as a fixed connection through screws, bolts or other spacers; a physical connection may also be a detachable connection, such as a snap connection or a snap-fit connection; a physical connection may also be an integral connection, such as a welded, bonded or integrally formed connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0046] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the appearances of "in one embodiment" or "in an embodiment" throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0047] Exemplarily, an embodiment of the present application provides a battery, which includes a secondary battery cover plate 100 as Figure 1 shown.

[0048] As an energy storage device, the battery can provide electrical energy for electrical equipment so that the electrical equipment can work properly. Especially for secondary batteries, they can be reused after being charged to activate the active substances after discharging, which greatly facilitates the application of electrical equipment.

[0049] The battery includes a pole column 300 and an electrode core 200, as Figure 2 shown. The electrode core 200 is provided with an electrode tab 201, and the electrode tab 201 is electrically connected to the pole column 300 so that current can be transmitted between the inside and outside circuits of the battery, enabling the battery to work properly.

[0050] In the battery provided with the above-mentioned secondary battery cover plate 100, the pole column 300 and the electrode tab 201 can be connected through the secondary battery cover plate 100 so that the battery can work properly.

[0051] The following will introduce the secondary battery cover plate 100 provided by the embodiment of the present application in detail with reference to the drawings.

[0052] Referring to Figure 1 , Figures 3 to 5 shown, the present application provides a secondary battery cover plate 100, which includes a connecting piece 10 and a lower plastic 20 stacked along the first direction X. In the first direction X, the connecting piece 10 has a first surface 11 facing the lower plastic 20, and the lower plastic 20 has a second surface 21 facing the connecting piece 10. A first limiting portion 30 is provided on the first surface 11, and a second limiting portion 40 is provided on the second surface 21. The first limiting portion 30 and the second limiting portion 40 cooperate to limit the connecting piece 10.

[0053] In the embodiment of the present application, since the first surface 11 faces the lower plastic 20 and the second surface 21 faces the connecting piece 10, the first surface 11 and the second surface 21 are opposite. Based on this, when the first limiting portion 30 is provided on the first surface 11 and the second limiting portion 40 is provided on the second surface 21, the first limiting portion 30 and the second limiting portion 40 are also opposite, and the two can cooperate to limit the connecting piece 10.

[0054] In this way, during subsequent assembly of the battery or in the actual application process of the battery, the possibility of the connecting piece 10 moving due to problems such as battery shaking and deformation of the tab 201 can be reduced, preventing the connecting piece 10 from shifting. Thus, the connecting piece 10 can be kept in a normal position, improving the reliability of battery use.

[0055] Among them, the secondary battery cover plate 100 includes a connecting piece 10 and a lower plastic 20. The lower plastic 20 can be used to install the terminal 300, and the connecting piece 10 can realize the connection between the terminal 300 and the tab 201.

[0056] As Figure 6 shown, the connecting piece 10 includes a fusing part 102. The fusing part 102 can be fused when the current is too large to cut off the circuit, reducing the possibility of battery thermal runaway. Since the secondary battery cover plate 100 proposed in this application can limit the connecting piece 10, it can also limit the fusing part 102 in the connecting piece 10.

[0057] In this way, the fusing part 102 can be kept in a normal position, reducing the possibility that the fusing part 102 loses its protection function due to offset.

[0058] Specifically, in the normal position, after the connecting piece 10 connects the tab 201 and the terminal 300, the fusing part 102 will be located between the tab 201 and the terminal 300. When the current is large, the fusing part 102 can be fused and the electrical connection between the tab 201 and the terminal 300 can be disconnected, thereby cutting off the circuit. At this time, the fusing part 102 has a normal protection function for the battery.

[0059] When the connecting piece 10 moves and the fusing part 102 shifts to the terminal 300, the terminal 300 will affect the function of the fusing part 102 due to its own conductivity. When the current is large, even if the fusing part 102 is normally fused, the terminal 300 will still be electrically connected to the tab 201 through other positions on the connecting piece 10, making the circuit still in an on state. At this time, the fusing part 102 loses its protection function, easily leading to battery thermal runaway.

[0060] Therefore, in this application, the connecting piece 10 can be limited by the cooperation of the first limiting part 30 and the second limiting part 40, so that the connecting piece 10 can be kept in a normal position, reducing the possibility that the fusing part 102 loses its function and even causing battery thermal runaway.

[0061] In the embodiment of this application, the first limiting part 30 and the second limiting part 40 can have different structures to achieve the limiting effect on the connecting piece 10. The following two are taken as examples for specific description.

[0062] The first structure: As Figure 4 、Figure 5 and Figure 6 As shown, a limiting hole 31 is provided on the first surface 11, and the limiting hole 31 can form a first limiting portion 30. Figure 5 and Figure 7 As shown, a limiting boss 41 is disposed on the second surface 21 , and the limiting boss 41 can form a second limiting portion 40 . The limiting boss 41 is engaged with the limiting hole 31 .

[0063] Through the above-mentioned arrangement, the limiting boss 41 can be snapped into the limiting hole 31, so that the limiting boss 41 can limit the movement of the connecting piece 10 through the hole wall of the limiting hole 31, so that the connecting piece 10 can be kept in a normal position, reducing the possibility that the fuse 102 loses its function or even causes thermal runaway of the battery.

[0064] In some embodiments, Figure 4 , Figure 5 and Figure 6 As shown, the limiting hole 31 can penetrate the connecting piece 10 along the first direction X, the limiting boss 41 is embedded in the limiting hole 31 , and the side of the limiting boss 41 facing away from the second surface 21 is located in the limiting hole 31 .

[0065] Through the above arrangement, on one hand, the limiting boss 41 can cooperate with the hole wall of the limiting hole 31 to limit the movement of the hole wall of the limiting hole 31 and realize the limiting of the connecting piece 10 .

[0066] On the other hand, after the limiting boss 31 is embedded in the limiting hole 31, the side of the limiting boss 41 facing away from the second surface 21 can be located in the limiting hole 21, reducing the possibility of the limiting boss 41 extending from the connecting plate 10 and affecting the setting of other components in the battery.

[0067] It should be noted that, in addition to the setting of the limiting hole 31 as a through hole, the limiting hole 31 can also be a blind hole. That is, a blind hole can be set on the first surface 11, and the blind hole can also be used as the first limiting portion 30 to cooperate with the limiting boss 41. When the lower plastic 20 and the connecting piece 10 are set, the limiting boss 41 can be embedded in the blind hole, and the connecting piece 10 is limited by the hole wall of the blind hole.

[0068] When the pole 300 is mounted on the lower plastic 20, the pole 300 protrudes from the side of the lower plastic 20 facing the connecting piece 10. The pole 300 protruding from the side of the lower plastic 20 facing the connecting piece 10 is connected to the connecting piece 10, so that there is a distance between the connecting piece 10 and the lower plastic 20. In order to make the limiting boss 41 match the limiting hole 31, the limiting boss 41 should protrude from the pole 300.

[0069] In order to make the arrangement of the pole 300, the limiting boss 41 and the connecting piece 10 clearer, the following will be combined with the attachedFigure 4 A detailed description will be given. Among them, the height of the limiting boss 41 is H1, the height of the pole column 300 protruding from the lower plastic 20 toward the side of the connecting piece 10 is H2, and the thickness of the connecting piece 10 is H3.

[0070] H1, H2, and H3 satisfy the condition of H2 ≤ H1 ≤ H2 + H3. In this way, the limiting boss 41 can limit the connecting piece 10, and the possibility that the limiting boss 41 affects the arrangement of other components in the battery can also be reduced.

[0071] In some embodiments, as Figure 6 and Figure 7 shown, the number of the limiting bosses 41 and the limiting holes 31 can both be multiple. The multiple limiting bosses 41 are snap - connected to the limiting holes 31 one by one.

[0072] In the present application, a plurality of limiting holes 31 can be provided on the first surface 11, and a plurality of limiting bosses 41 can be provided on the second surface 21. Thus, the multiple limiting bosses 41 can be snap - connected in the multiple limiting holes 31 to limit the connecting piece 10 at multiple positions, so that the limiting effect of the first limiting portion 30 and the second limiting portion 40 on the connecting piece 10 is better.

[0073] It should be noted that the number of the limiting bosses 41 and the limiting holes 31 can both be 2, 3, 4, 5, etc. The specific number of the limiting bosses 41 and the limiting holes 31 is not specifically limited in the embodiments of the present application.

[0074] In some embodiments, as Figure 5 and Figure 6 shown, the connecting piece 10 can include a pole - column connecting portion 101, a fusing portion 102, and an ear - connecting portion 103 arranged along the second direction Y. The fusing portion 102 is connected between the pole - column connecting portion 101 and the ear - connecting portion 103. The limiting hole 31 is provided on the surface of at least one of the fusing portion 102, the ear - connecting portion 103, and the pole - column connecting portion 101 facing the lower plastic 20. Among them, the first direction X is perpendicular to the second direction Y.

[0075] The connecting piece 10 further includes a pole - column connecting portion 101 and an ear - connecting portion 103. The ear - connecting portion 103 is used to connect the ear 201, and the pole - column connecting portion 101 is used to connect the pole column 300.

[0076] For example, the limiting hole 31 can be provided on the ear - connecting portion 103, or the limiting hole 31 can be provided on the fusing portion 102, or the limiting hole 31 can be provided on both the ear - connecting portion 103, the pole - column connecting portion 101, and the fusing portion 102, etc.

[0077] For the specific setting position of the limit hole 31, the embodiments of the present application do not make specific limitations here. The limit boss 41 can be set according to the position of the limit hole 31 so that the limit boss 41 can cooperate with the limit hole 31.

[0078] Wherein, the second direction Y is the direction from the pole connection part 101 to the tab connection part 103, perpendicular to the first direction X. In a square battery, the battery includes two pole columns 300 distributed along the second direction Y, namely the positive pole column and the negative pole column respectively.

[0079] In order to connect the positive pole column and the negative pole column to the battery cell 200, two connection pieces 10 distributed along the second direction Y can be arranged on the lower plastic 20, and the two connection pieces 10 can respectively correspond to connect the positive pole column and the negative pole column. At this time, limit bosses 41 can be arranged at positions on the lower plastic 20 opposite to the two connection pieces 10 to limit both of the two connection pieces 10.

[0080] It should be noted that the tab 201 is generally a relatively thin structural member and has a certain elasticity itself, so it is easy to deform. Based on this, during the connection process of the tab 201, the subsequent assembly or use of the battery, it is very likely that the tab 201 deforms and drives the connection piece 10 to shift through the tab connection part 103.

[0081] Therefore, in order to make the limiting effect of the first limiting part 30 and the second limiting part 40 on the connection piece 10 better and reduce the processing difficulty, the first limiting part 30 can be arranged on the tab connection part 103 to directly limit the tab connection part 103 and improve the sensitivity of limiting the connection piece 10 after the tab 201 deforms.

[0082] Of course, when the first limiting part 30 is arranged on the tab connection part 103, the first limiting part 30 can also be arranged on the fusing part 102 and / or the pole connection part 101 to strengthen the limiting of the connection piece 10.

[0083] In addition, after the fusing part 102 fuses, the tab connection part 103 and the pole connection part 101 will be disconnected to form two separated parts. At this time, if the tab 201 deforms and drives the tab connection part 103 to shift, it may occur that the tab connection part 103 and the pole connection part 101 are lapped again to connect the circuit, which is likely to cause the battery to have a thermal runaway.

[0084] However, in the present application, the first limiting part 30 is arranged on the tab connection part 103, and after the fusing part 102 is disconnected, the tab connection part 103 can still be limited, which can reduce the possibility that the tab connection part 103 moves to lap with the pole connection part 101, thereby connecting the circuit and causing the battery to have a thermal runaway.

[0085] In some embodiments, the current-carrying area of the fusing portion 102 is S1, the current-carrying area of the tab connecting portion 103 is S2, and the current-carrying area of the terminal connecting portion 101 is S3. S1, S2, and S3 may satisfy: S1 < 2×S2 and S1 < S3. Wherein, S1 is the area of the projection of the fusing portion 102 in the second direction Y, S2 is the area of the projection of the tab connecting portion 103 in the third direction Z, and S3 is the area of the projection of the terminal connecting portion 101 in the second direction Y. The first direction X and the second direction Y are both perpendicular to the third direction Z.

[0086] When the first limiting portion 30 is the limiting hole 31, the current-carrying area at the position where the limiting hole 31 is provided on the connecting piece 10 will decrease. Therefore, when the limiting hole 31 is provided in the tab connecting portion 103 and / or the terminal connecting portion 101, the current-carrying area of the tab connecting portion 103 and / or the terminal connecting portion 101 will decrease.

[0087] In order to enable the fusing portion 102 to fuse first when the current is large, the current-carrying area of the fusing portion 102 should be set to be small so that the resistance of the fusing portion 102 is large. Further, when the current is large, the temperature of the fusing portion 102 can rise and be fused, so that the circuit is disconnected.

[0088] In the present application, in order to enable the fusing portion 102 to play a protective role, the current-carrying area of the fusing portion 102 needs to be smaller than the current-carrying areas of the remaining portions of the tab connecting portion 103 except the limiting hole 31 and the remaining portion of the terminal connecting portion 101 except the limiting hole 31.

[0089] That is, after the limiting hole 31 is provided, S1 < 2×S2 and S1 < S3, which can make the area of the fusing portion 102 small, facilitate the fusing portion 102 to fuse first, and play a protective role.

[0090] Wherein, when the battery forms a circuit, at the connecting piece 10, the current flows from the tab connecting portion 103 to the terminal connecting portion 101.

[0091] Taking the secondary battery cover plate 100 placed in the Figure 1 shown orientation as an example for illustration, combined with Figure 2 , the tabs 201 of the two battery cells 200 are connected to the terminals 300 through the connecting piece 10. The tab connecting portion 103 specifically includes two sub-connecting portions, and the two sub-connecting portions are respectively connected to the tab 201 of one battery cell 200. The distribution direction of the two sub-connecting portions is the third direction Z.

[0092] Combined with Figure 2 and Figure 6 , still taking the secondary battery cover plate 100 placed in the Figure 1The following description is based on the shown orientation. In the current loop, the current at the tab 201 of the upper cell 200 flows downward, and the current at the tab 201 of the lower cell 200 flows upward. The two circuits converge at the fusing part 102 and flow towards the terminal connection part 101. Therefore, the current in the fusing part 102 and the terminal connection part 101 is twice the current in the tab connection part 103.

[0093] The current-carrying area is the area of the cross-section perpendicular to the current flow direction. For the fusing part 102 and the terminal connection part 101, the current flows along the second direction Y. The cross-sections of the fusing part 102 and the terminal connection part 101 in the second direction Y are perpendicular to the current flow direction. Therefore, the current-carrying area of the fusing part 102 is the area of the projection of the fusing part 102 in the second direction Y, and the current-carrying area of the terminal connection part 101 is the area of the projection of the terminal connection part 101 in the second direction Y.

[0094] For the tab connection part 103, the current flows along the third direction Z. The cross-section of the tab connection part 103 in the third direction Z is perpendicular to the current flow direction. Therefore, the current-carrying area of the tab connection part 103 is the area of the projection of the tab connection part 103 in the third direction Z.

[0095] Since the current in the fusing part 102 is the sum of the two currents in the tab connection part 103, the current-carrying area of the fusing part 102 only needs to be less than twice the current-carrying area of the tab connection part 103, so that the fusing part 102 can fuse before the tab connection part 103.

[0096] It should be noted that in actual applications, the current-carrying areas of the tab connection part 103, the terminal connection part 101, and the fusing part 102 may be different. At this time, in order to make the fusing part 102 fuse before the tab connection part 103 and the terminal connection part 101. S2 can be the minimum projected area of the tab connection part 103 in the third direction Z, S3 can be the minimum projected area of the terminal connection part 101 in the second direction Y, and S1 is the maximum projected area of the fusing part 102 in the second direction Y.

[0097] The second structure: A limiting protrusion can be provided on the first surface 11, and the limiting protrusion forms a first limiting portion 30. A limiting groove is provided on the second surface 21, and the limiting groove forms a second limiting portion 40. The limiting protrusion is embedded in the limiting groove.

[0098] Through the above settings, the limiting protrusion can be embedded in the limiting groove, and the limiting groove can restrict the movement of the limiting boss 41 through its groove wall. Thus, the movement of the connecting piece 10 can be restricted, so that the connecting piece 10 can be kept in the normal position, reducing the possibility that the fusing part 102 easily loses its function and even causing thermal runaway of the battery.

[0099] Similar to the first structure, the limiting protrusions can be provided on at least part of the tab connection portion 103, the fusing portion 102, and the pole connection portion 101, and the number of the limiting protrusions and the limiting grooves can both be multiple.

[0100] In some embodiments, mounting bosses can be provided on the second surface 21, and the limiting grooves are provided on the mounting bosses.

[0101] Generally, the lower plastic 20 is an injection molded part, and its dimension in the first direction X is small, making the lower plastic 20 thin. This increases the difficulty of providing the limiting grooves on the lower plastic 20, and it is easy for the limiting grooves to penetrate through the lower plastic 20, resulting in the problem of insulation failure of the lower plastic 20.

[0102] In the present application, mounting bosses are provided on the second surface 21, and the limiting grooves can be provided on the mounting bosses, which is convenient for the formation of the limiting grooves and can also reduce the possibility of the problem of insulation failure of the lower plastic 20 caused by the provision of the limiting grooves.

[0103] It should be noted that, in order to further reduce the processing difficulty, the mounting bosses can be formed together with the lower plastic 20 by injection molding.

[0104] It should also be noted that the first structure and the second structure can be provided separately or in combination, and both can achieve the limitation of the connecting piece 10.

[0105] In some embodiments, as Figure 7 shown, a limiting block 50 can also be provided on the second surface 21, and the limiting block 50 can also limit the connecting piece 10.

[0106] As Figure 4 and Figure 6 shown, the connecting piece 10 has a third surface 12 opposite to the first surface 11, and there is an abutting surface 60 between the first surface 11 and the third surface 12. The abutting surface 60 abuts against the limiting block 50 to limit the connecting piece 10.

[0107] Therefore, the first surface 11 and the third surface 12 are two opposite surfaces of the connecting piece 10 in the first direction X, the abutting surface 60 is located between the first surface 11 and the third surface 12, and is the side surface of the connecting piece 10 surrounding the first direction X. The abutting surface 60 abuts against the limiting block 50, which can also limit the connecting piece 10 and reduce the possibility of the connecting piece 10 moving.

[0108] As can be seen from the foregoing description, the tab 201 is prone to deformation, which makes it highly likely that the tab connection portion 103 is displaced. Therefore, when the limiting block 50 is set to abut against the abutting surface 60, the limiting block 50 can abut against the tab connection portion 103 to limit the tab connection portion 103.

[0109] Furthermore, the limiting block 50 can abut against the side surface of the tab connection portion 103 facing the pole connection portion 101 to restrict the movement of the tab connection portion 103 in the direction approaching the pole connection portion 101. In this way, the connection piece 10 can be limited when the fusing portion 102 is not fused, and the tab connection portion 103 can be limited after the fusing portion 102 is fused, reducing the possibility that the tab connection portion 103 is lapped again with the pole connection portion 101 to form a closed circuit.

[0110] The connection between the tab connection portion 103 and the tab 201 limits the movement range of the tab connection portion 103. Thus, when there are two connection pieces 10 distributed along the second direction Y on the lower plastic 20, the possibility that the tab connection portion 103 of one connection piece 10 moves to overlap with the other connection piece 10 can be reduced.

[0111] Of course, in order to make the abutment of the limiting block 50 against the abutting surface 60 have a better limiting effect on the tab connection portion 103, a plurality of limiting blocks 50 can be provided on the second surface 21. For example, 2, 3, 4 or 5 limiting blocks 50 can be provided, and the plurality of limiting blocks 50 can abut against different positions of the abutting surface 60.

[0112] For example, the side surface of the tab connection portion 103 facing away from the pole connection portion 101, and / or the side surface of the pole connection portion 101 facing away from the tab connection portion 103 can also abut against the limiting block 50, etc. In this regard, the embodiments of the present application do not make specific limitations.

[0113] It should also be noted that the limiting block 50 can also be provided separately to realize the limiting of the connection piece 10. That is, only the limiting block 50 can be provided on the second surface 21. Through the cooperation of the limiting block 50 and the abutting surface 60, the connection piece 10 can also be kept in the normal position, reducing the possibility that the fusing portion 102 easily loses its function and even causes thermal runaway of the battery.

[0114] In the embodiments of the present application, since the first surface 11 faces the connection piece 10 and the second surface 21 faces the lower plastic 20, the first surface 11 and the second surface 21 are opposite. Thus, the first limiting portion 30 and the second limiting portion 40 are also opposite, and the two can cooperate to realize the limiting of the connection piece 10.

[0115] In this way, during subsequent assembly of the battery or in the actual application process of the battery, the possibility of the connecting piece 10 moving due to problems such as battery shaking and deformation of the tab 201 can be reduced, preventing the connecting piece 10 from shifting. Thereby, the connecting piece 10 can be in a normal position, improving the reliability of battery use.

[0116] Finally, it should be noted that the above embodiments are only specific implementation manners of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A secondary battery cover plate, characterized in that, It includes a connecting sheet and a lower plastic stacked along a first direction: In the first direction, the connecting piece has a first surface facing the lower plastic, and the lower plastic has a second surface facing the connecting piece; A first limiting portion is disposed on the first surface, and a second limiting portion is disposed on the second surface. The first limiting portion cooperates with the second limiting portion to limit the connection piece.

2. The secondary battery cover plate according to claim 1, characterized in that, A limiting hole is arranged on the first surface, the limiting hole forms the first limiting portion, and a limiting boss is arranged on the second surface, the limiting boss forms the second limiting portion; The limiting boss is clamped in the limiting hole.

3. The secondary battery cover plate according to claim 2, characterized in that, The limiting hole passes through the connecting piece along the first direction, the limiting boss is embedded in the limiting hole, and a side of the limiting boss facing away from the second surface is located in the limiting hole.

4. The secondary battery cover plate according to claim 2, characterized in that, The number of the limiting bosses and the number of the limiting holes are both multiple; The plurality of limiting bosses are correspondingly engaged with the limiting holes one by one.

5. The secondary battery cover plate according to claim 2, wherein, The connecting piece includes a pole connecting portion, a fuse portion and a pole lug connecting portion arranged along the second direction, and the fuse portion is connected between the pole connecting portion and the pole lug connecting portion; The limiting hole is provided on the surface of at least one of the fuse part, the pole lug connection part and the pole connection part facing the lower plastic; The first direction is perpendicular to the second direction.

6. The secondary battery cover plate according to claim 5, characterized in that, The conduction area of the fuse part is S1, the conduction area of the pole lug connection part is S2, and the conduction area of the pole connection part is S3; S1, S2 and S3 satisfy: S1<2×S2, and S1<S3; Wherein, S1 is the projection area of the fuse portion in the second direction, S2 is the projection area of the tab connection portion in the third direction, and S3 is the projection area of the pole connection portion in the second direction; The first direction and the second direction are both perpendicular to the third direction.

7. The secondary battery cover plate according to claim 1, characterized in that, A limiting protrusion is provided on the first surface, and the limiting protrusion forms the first limiting portion; A limiting groove is provided on the second surface, and the limiting groove forms the second limiting portion; The limiting protrusion is embedded in the limiting groove.

8. The secondary battery cover plate according to claim 7, wherein The second surface is provided with a mounting boss, and the limiting groove is provided on the mounting boss.

9. The secondary battery cover plate according to claim 1, characterized in that, A limit block is also arranged on the second surface, the connecting piece has a third surface opposite to the first surface, and an abutting surface is arranged between the first surface and the third surface; The abutting surface abuts against the limiting block to limit the connecting piece.

10. A battery, characterized in that, The battery comprises the secondary battery cover plate according to any one of claims 1 to 9.

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