Electrode lead member, cover assembly, secondary battery, and electronic device

Abstract

PURPOSE: To provide an electrode lead member, a cover assembly, a secondary battery, and an electronic device related to the battery technology field.SOLUTION: An electrode lead member includes a connection plate and an electrode terminal. The connection plate includes a terminal connection zone, a tab connection zone, and a transition connection zone for connecting the terminal connection zone and the tab connection zone. The electrode terminal is connected to the terminal connection zone. The transition connection zone is provided with at least one first recess, the first recess is recessed in the thickness direction of the connection plate, and the inner contour of the sidewall of the first recess is located inside the outer contour of the sidewall of the connection plate. This structure reduces the weight of the connection plate and improves the mass energy density of the battery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the field of batteries, and in particular to an electrode lead member, a cover assembly, a secondary battery, and an electronic device. [Background technology]

[0002] Batteries are used in a wide range of electronic devices, such as mobile phones, laptops, battery cars, electric cars, electric planes, electric boats, electric toy cars, electric toy boats, electric toy planes, and power tools. At present, common batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and secondary alkaline zinc-manganese batteries. Among all these batteries, lithium-ion batteries have become the mainstream power batteries used in new energy vehicles due to their advantages of high specific energy, high specific power, long life, and low cost. Summary of the Invention [Problem to be solved by the invention]

[0003] In order to improve the safety performance and installation efficiency of the battery, the conventional positive and negative electrode connection sheet and ultrasonic welding protection sheet are eliminated from the welding of the wound cell and cover of the lithium ion battery. The wound cell is directly laser welded to the electrode bottom plate through the tab, so the electrode bottom plate needs to be enlarged. However, by enlarging the electrode bottom plate, the electrode becomes heavy, especially on the negative side. The electrode bottom plate on the negative side is mainly made of copper. Copper has a high density and is heavy, which causes a decrease in the mass density of the battery and affects the electrical performance of the battery. Therefore, it is necessary to provide an electrode lead member, a cover assembly, a secondary battery, and an electronic device that can solve the above problems. [Means for solving the problem]

[0004] Taking into consideration the above-mentioned shortcomings found in the prior art, the present invention provides an electrode lead member, a cover assembly, a secondary battery, and an electronic device that can solve the problem of a reduction in battery mass density caused by the heavy weight of the electrode bottom plate.

[0005] To achieve the above and other related objectives, the present invention provides an electrode lead-out member including a connection plate and an electrode terminal, the connection plate including a terminal connection zone, a tab connection zone, and a transition connection zone for connecting the terminal connection zone and the tab connection zone, the electrode terminal being connected to the terminal connection zone, the transition connection zone being provided with at least one first recess, the at least one first recess being recessed in a thickness direction of the connection plate, and an inner contour of a sidewall of the at least one first recess being located inside an outer contour of a sidewall of the connection plate.

[0006] In the electrode lead member provided by one embodiment of the present invention, a projection of the at least one first recess along the thickness direction is located outside the tab connection zone.

[0007] In an electrode lead member provided by one embodiment of the present invention, at least one first recess is recessed in a first direction, and the first direction faces from one side of the connection plate to which the electrode terminal is connected to the other side of the connection plate.

[0008] In the electrode lead member provided by one embodiment of the present invention, the at least one first recess is a through hole that penetrates the connecting plate in the thickness direction.

[0009] In an electrode lead member provided by one embodiment of the present invention, the thickness of the connecting plate is h, the minimum distance between the inner contour of the side wall of the at least one first recess and the outer contour of the side wall of the connecting plate is D, and D satisfies 0.5h≦D≦1.5h.

[0010] In the electrode lead member provided by one embodiment of the present invention, the minimum distance between the inner contour of the sidewall of the at least one first recess and the outer contour of the sidewall of the connecting plate is D, where 0≦D≦10 mm.

[0011] In an electrode lead member according to one embodiment of the present invention, a second recess is provided at a position extending in a second direction of the connection plate, the second direction being oriented from the terminal connection zone to the tab connection zone, the second recess is recessed in the thickness direction of the connection plate, and a fuse portion is formed between the second recess and the at least one first recess.

[0012] In an electrode lead member provided by one embodiment of the present invention, each transition connection zone on one side of the terminal connection zone is provided with at least one first recess. The second recess is disposed at a position away from the terminal connection zone of the connection plate between the at least one first recess on both sides. The at least one first recess has a polygonal column structure, and the second recess has a polygonal column structure. The second recess has a side away from the terminal connection zone that penetrates one side of the connection plate, and the fuse portion is formed at a corner vertex between the at least one first recess and the second recess.

[0013] In an electrode lead member provided by one embodiment of the present invention, the at least one first recess is a through hole penetrating the connection plate in the thickness direction, and the second recess is a through hole penetrating the connection plate in the thickness direction, the length of the fuse portion is C, the minimum distance between the outer contour of the at least one first recess and the outer contour of the connection plate is D, the width of the connection plate where the tab connection zone is located is A, and C+D <Aである。

[0014] In the electrode lead member provided according to one embodiment of the present invention, the second recess is a through hole that penetrates the connection plate in the thickness direction.

[0015] In the electrode lead member provided by one embodiment of the present invention, the connection plate and the electrode terminal are of one unitary structure, or the terminal connection zone is higher than the transition connection zone in the thickness direction. The electrode terminal and the connection plate are made of different materials.

[0016] In an electrode lead member provided by one embodiment of the present invention, the material of the electrode terminal is a metal containing aluminum, the material of the connection plate is a metal containing copper, and the electrode terminal and the terminal connection zone are connected by friction welding.

[0017] The present invention further provides a cover assembly including a cover body, a lower insulating member, and the above-mentioned electrode lead member provided by the present invention. The lower insulating member is disposed on one side of the cover body. An electrode terminal of the electrode lead member penetrates the lower insulating member and is at least partially disposed within the through hole. At least a portion of the connection plate of the electrode lead member abuts against one side of the lower insulating member remote from the cover body.

[0018] In a cover assembly provided by one embodiment of the present invention, one side of the lower insulating member facing the connecting plate is provided with a protrusion that mates with at least one first recess of the electrode lead member, and the protrusion is embedded and fits into the at least one first recess.

[0019] According to one embodiment of the present invention, a cover assembly is provided in which each terminal connection zone on one side of the transition connection zone is provided with at least one first recess.

[0020] In a cover assembly provided by one embodiment of the present invention, a height of the protrusion is h1, a depth of the at least one first recess is h2, and a gap between the transition connection zone and the lower insulating member is h3, where h1, h2, and h3 satisfy h1≦h2+h3.

[0021] In the cover assembly provided by one embodiment of the present invention, a gap d is provided between the protrusion and the inner wall surface of the at least one first recess, and the gap d is d≧0.1 mm, and the gap d ensures that the movement area of ​​the lower insulating member does not exceed the coverage range of the cover body.

[0022] In the cover assembly provided by one embodiment of the present invention, the protrusion is a groove on one side facing the cover body.

[0023] In a cover assembly provided by one embodiment of the present invention, the protrusion includes a bottom and a side. The side is connected to the lower insulating member and extends in a direction away from the cover body, and the bottom is connected to one side of the side remote from the cover body. The bottom and / or the side are provided with a liquid guide hole.

[0024] In a cover assembly provided by one embodiment of the present invention, the cover assembly includes a first electrode lead member and a second electrode lead member, and a first recess in a connection plate of the first electrode lead member and a first recess in a connection plate of the second electrode lead member are not interchangeable.

[0025] In a cover assembly provided by one embodiment of the present invention, the first recess of the first electrode lead member has a first shape and the first recess of the second electrode lead member has a second shape, the first shape being different from the second shape.

[0026] In a cover assembly provided by one embodiment of the present invention, a first recess of a first electrode lead member is disposed at a first position of a connecting plate, a first recess of a second electrode lead member is disposed at a second position of the connecting plate, and the first and second positions are located at different positions of a transition connection zone.

[0027] The present invention further provides a secondary battery including a casing, an electrode assembly, and the above-mentioned cover assembly provided by the present invention. The electrode assembly is housed in the casing and includes a body portion and a tab connected to the body portion. The tab and the electrode lead member of the electrode assembly are connected at a tab connection zone, and the cover body of the cover assembly covers the opening of the casing.

[0028] The present invention further provides an electronic device including the above secondary battery. Effect of the Invention

[0029] In the present invention, the electrode lead member has a first recess recessed in the thickness direction on one side away from the tab connection zone of the connection plate, so that the thickness of the connection plate is reduced in this zone. By arranging the first recess, not only the weight of the connection plate is reduced, but also it can be matched with the lower insulating member in the cover assembly. In this way, positioning is achieved and the position of the lower insulating member is prevented from being shifted, which affects the assembly. By arranging a second recess recessed in the thickness direction on the connection plate, the weight of the connection plate is further reduced. Furthermore, a fuse portion is formed between the second recess and the first recess, so that overcurrent protection of the connection plate is realized.

[0030] In the present invention, a protrusion that fits with the first recess is disposed on the lower insulating member of the cover assembly, and the protrusion and the first recess are embedded in each other to prevent the lower insulating member from being misaligned and affecting assembly. Furthermore, the weight of the lower insulating member is reduced by configuring one side of the protrusion away from the connection plate in a hollow groove. By disposing a liquid guide hole, electrolyte that flows into the groove when liquid is injected is quickly guided. [Brief description of the drawings]

[0031] In order to more clearly describe the technical solutions provided in the embodiments of the present invention or the prior art, some accompanying drawings necessary for describing the embodiments or the prior art are briefly introduced as follows: Obviously, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative labor.

[0032] [Figure 1] 1 is a schematic diagram showing an overall structure of an electrode lead member according to one embodiment of the present invention. [Diagram 2] 3 is a schematic diagram showing the structure of a connecting plate of an electrode lead member according to one embodiment of the present invention. FIG. [Diagram 3] FIG. 4 is a schematic view of the structure of an electrode lead member according to one embodiment of the present invention, seen from another angle. [Figure 4] 3 is a schematic diagram showing the structure of a connecting plate of an electrode lead member according to one embodiment of the present invention. FIG. [Diagram 5] 13 is a schematic diagram of a structure of a connection plate of an electrode lead member according to another embodiment of the present invention. FIG. [Figure 6] 1 is a schematic diagram of a structure of a cover assembly according to one embodiment of the present invention. [Figure 7] FIG. 2 is a schematic exploded view of a cover assembly according to one embodiment of the present invention. [Figure 8] 1 is a schematic diagram of a structure of a lower insulating member of a cover assembly according to one embodiment of the present invention. [Figure 9] 4 is a schematic diagram of a cover assembly according to one embodiment of the present invention from another angle. FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line AA in FIG. [Figure 11] 1 is a schematic diagram of the structure of a secondary battery according to one embodiment of the present invention. [Figure 12] 1 is a schematic diagram of a structure of an electronic device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The implementation of the present invention will be described below through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. In addition, the present invention can be implemented or applied through different specific implementation methods. The details in this specification can be modified or changed based on different perspectives and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other if there is no contradiction.

[0034] When numerical ranges are given in the embodiments, it should be understood that the two end points of each numerical range and any numerical value between the two end points can be selected unless otherwise specified in the present invention.Unless otherwise defined, all technical and scientific terms used in the present invention are consistent with the prior art knowledge and the description of the present invention by those skilled in the art.Any method, device and material of the prior art that is similar or equivalent to the method, device and material described in the embodiments of the present invention can also be used to implement the present invention.

[0035] The drawings provided in the embodiments merely show the basic idea of ​​the present invention in a schematic manner. Therefore, the drawings show only the components related to the present invention, not the number, shape, and size of the components in the actual implementation. In the actual implementation, the type, quantity, and ratio of the components can be freely changed, and the layout of the components can be more complicated. It should be noted that the terms "upper", "lower", "left", "right", "middle", "one" and the like cited in this specification are for convenience of explanation and are not used to limit the scope of the present invention. Changes or adjustments of the relative relationships should also be considered as the scope of the present invention if there is no substantial change in the technical content.

[0036] In the following description, numerous details are discussed to more fully explain the embodiments of the present invention. However, it will be apparent that the embodiments of the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the embodiments of the present invention.

[0037] 1 to 12, the present invention provides an electrode lead member 140, a cover assembly 130, a secondary battery 100, and an electronic device 10. Here, a recess is provided in the connection plate of the electrode lead member 140 in the thickness direction, and by arranging the recess, the weight of the connection plate is reduced and the mass energy density of the battery is improved.

[0038] In the present invention, the secondary battery 100 may be a lithium ion secondary battery, a sodium ion secondary battery, a lithium iron phosphate secondary battery, etc., but the present invention is not limited thereto. The secondary battery 100 may be cylindrical, rectangular, prismatic, or other shapes, but the present invention is not limited thereto. The secondary battery 100 includes a casing 110, an electrode assembly 120, and a cover assembly 130, and the electrode assembly 120 is housed in the casing 110. The electrode assembly 120 includes a main body and a tab connected to the main body. The cover assembly 130 includes a cover body 131, a lower insulating member 132, and an electrode lead member 140, and the lower insulating member 132 is disposed on one side of the cover body 131 facing the electrode assembly 120. The electrode lead member 140 penetrates the lower insulating member 132, is sealed and insulated from the cover body 131, and is electrically connected to the tab of the electrode assembly 120 to lead out a current of the electrode assembly 120. The cover body 131 is sealed with and covers the opening of the casing 110, and together with the casing 110 forms a closed battery environment to prevent liquids and other foreign matter from affecting the normal operation of the battery.

[0039] Referring to FIG. 1, the electrode lead member 140 provided by the present invention includes a connection plate 141 and an electrode terminal 142. The electrode terminal 142 protrudes from the surface of the connection plate 141 and forms an integral structure with the connection plate 141. The connection plate 141 is connected to the tab of the electrode assembly 120, so that the current of the electrode assembly 120 is guided to the electrode terminal 142. The present invention omits the original connection piece structure and provides the connection plate 141 and the electrode terminal 142 as an integral structure. In this way, the contact area between the electrode lead member 140 and the tab is increased, and the safety performance of the battery is improved. In addition, the welding process between the electrode terminal and the connection piece is omitted, so that the efficiency of battery manufacturing is improved.

[0040] 1 and 2, in some embodiments, the connection plate 141 has a flat structure and is made of a conductive material such as copper or aluminum. The connection plate 141 includes a terminal connection zone 1411, a tab connection zone 1412, and a transition connection zone 1413 for connecting the terminal connection zone 1411 and the tab connection zone 1412. The terminal connection zone 1411 is configured to connect to the electrode terminal 142, and the tab connection zone 1412 is configured to connect to a tab of the electrode assembly 120. The electrode terminal 142 is disposed on the terminal connection zone 1411, and the electrode terminal 142 and the connection plate 141 may be a one-piece structure or may be two independent parts fixedly connected as a whole via welding, such as friction welding. Furthermore, the terminal connection zone 1411 is higher than the transition connection zone 1413 in the thickness direction of the connection plate 141. That is, the annular boss 1422 is disposed in the terminal connection zone 1411, and the electrode terminal 142 is disposed on the annular boss 1422, thus ensuring the flatness of the connection surface and the reliability of the welding. The electrode terminal 142 is a solid structure made of a conductive material, and ensures the flow area of ​​the electrode terminal 142 to ensure the stability of current transmission. The electrode terminal 142 may be configured in a columnar structure to facilitate connection with an external electronic device or charging device. The end face of the electrode terminal 142 opposite to the connection plate 141 is recessed to form a recess, which is used for connecting to an electric device or a charging device. A screw may be provided on the inner wall of the recess to improve the convenience of connection. The electrode terminal 142 and the connection plate 141 may be made of a metal material having a certain strength. Furthermore, the electrode terminal 142 is made of a metal containing aluminum, for example, an aluminum alloy. The connection plate 141 is made of a metal containing copper, for example, copper. When the electrode lead member 140 is a negative electrode lead member, the electrode terminal 142 and the connection plate 141 are made of different materials, for example, the electrode terminal 142 is made of an aluminum alloy and the connection plate 141 is made of copper. When the electrode lead member 140 is a positive electrode lead member, the electrode terminal 142 and the connection plate 141 are made of the same material, for example, an aluminum alloy.

[0041] 1 and 2, the tab of the electrode assembly 120 is directly welded to the connection plate 141 of the electrode lead member 140. In order to ensure the reliability of the welding, the connection plate 141 needs to be enlarged. However, the enlargement of the connection plate 141 increases the weight, especially when the connection plate 141 is made of copper, the weight becomes even heavier. To solve this problem, in the present invention, at least one first recess 1414 is provided in the transition connection zone 1413 of the connection plate 141, and the first recess 1414 is recessed in the thickness direction of the connection plate 141, and the inner contour of its side wall is located inside the outer contour of the side wall of the connection plate 141. In order to ensure the reliability of the welding between the electrode lead member 140 and the tab, the first recess 1414 is located in the outer zone of the tab connection zone 1412. That is, the projection of the first recess 1414 along the thickness direction of the connection plate 141 is located outside the tab connection zone 1412. In the present invention, the first recess 1414 may be formed by recessing one side of the connection plate 141 connected to the electrode terminal 142 toward the other side (first direction) of the connection plate 141, by recessing the other side of the connection plate 141 toward one side (opposite to the first direction) connected to the electrode terminal 142, or by recessing from the center of the connection plate 141 toward both sides. The direction in which the first recess 1414 is recessed is not particularly limited. Preferably, the first recess 1414 faces from one side of the connection plate 141 connected to the electrode terminal 142 toward the other side of the connection plate 141. By arranging the first recess 1413, the connection plate 141 can be made thinner at this position, and therefore the weight of the connection plate 141 is reduced.

[0042] 2, the first recess 1414 may be a through hole penetrating the connecting plate 141 in the thickness direction, or may be a groove not penetrating the connecting plate 141 in the thickness direction. Preferably, the first recess 1414 is a through hole penetrating the connecting plate 141 in the thickness direction, so that the weight of the connecting plate 141 can be reduced to the maximum. More preferably, the first recess 1414 is provided on both sides of the terminal connecting zone 1411, so that the weight of the connecting plate 141 can be further reduced.

[0043] 2 and 3, the relationship between the size of the first recess 1414 and the size of the connection plate 141 can be selected according to specific circumstances. In some embodiments, the thickness of the connection plate is h, the minimum distance between the inner contour of the sidewall of the first recess 1414 and the outer contour of the sidewall of the connection plate 141 is D, and these two dimensions satisfy the following relationship: 0.5h≦D≦1.5h, or even 0.8h≦D≦1.2h. The value of D is in the range of 0≦D≦10mm, or even 3≦D≦7mm, such as 5mm, so that the safety and reliability of the battery are ensured.

[0044] 1 to 3, in some embodiments, the connecting plate 141 is further provided with a second recess 1415 recessed in the thickness direction. Similarly, the second recess 1415 may be a through hole penetrating the connecting plate 141 in the thickness direction, or may be a groove not penetrating the connecting plate 141. It is preferably a through hole. The second recess 1415 is provided at a position where the connecting plate 141 extends in the second direction. Here, the second direction is from the terminal connection zone 1411 to the tab connection zone 1412, and one side of the second recess 1415 away from the terminal connection zone 1411 and an edge of the connecting plate 141 away from the terminal connection zone 1411 penetrate each other. That is, the second recess 1415 is formed by a depression of the edge of the connecting plate 141 away from the terminal connection zone 1411. The tab connection zone 1415 is formed between two side edges of the second recess 1415 and the edge of the connecting plate 141. By arranging the second recess 1415, the weight of the connecting plate 141 is further reduced, and the mass energy density of the battery is improved.

[0045] Furthermore, the connection plate zone between the second recess 1415 and the first recess 1414 forms a fuse portion. Specifically, each transition connection zone 1413 on one side of the terminal connection zone 1411 is provided with a first recess 1414, and the second recess 1415 is disposed at a position away from the terminal connection zone 1411 of the connection plate 141 between the first recesses 1414 on both sides. The zones of the connection plate 141 on both sides of the second recess 1415 are tab connection zones 1412. The first recess 1414 has a polygonal column structure such as a square structure, and the second recess 1415 has a polygonal column structure such as a U-shaped structure. The open end of the U shape faces the edge of the connection plate 141, and the fuse portion is formed between the corner vertices of the first recess 1414 and the second recess 1415.

[0046] Referring to FIGS. 3 to 5, in one embodiment, both the first recess 1414 and the second recess 1415 are through-hole structures that penetrate the connection plate 141 in the thickness direction. Here, let the length of the fuse portion be C, the minimum distance between the outer contour of the first recess 1414 and the outer contour of the connection plate 141 be D, and the width of the connection plate 141 where the tab connection zone 1412 is located (the width between the outer contour of the side wall of the connection plate 141 and the inner contour of the side wall of the second recess 1414) be A, and C + D < A. When a short circuit occurs, after the current increases and the heat rises, the connection plate 141 melts at the fuse portion, and the battery is disconnected. In this way, ignition and explosion of the battery due to short circuit are prevented, and overcurrent protection of the connection plate 141 is realized. In other embodiments, the first recess 1414 and the second recess 1415 may be grooves that do not penetrate the connection plate 141. In this case, the cross-sectional area of the fuse portion needs to satisfy the overcurrent protection of the connection plate 141.

[0047] Referring to FIGS. 4 and 5, in one embodiment, the bottom of the first recess 1414 is higher than the top of the second recess 1415. Specifically, taking the center position of the terminal connection zone 1411 as the origin O, the center line passing through the origin O and extending in the length direction of the connection plate 141 as m1, and the center line passing through the origin O and extending in the width direction of the connection plate 141 as m2. Let the minimum distance from the bottom of the first recess 1414 to the center line m1 be d1, the minimum distance from the side of the first recess 1414 to the center line m2 be d3, the minimum distance from the top of the second recess 1415 to the center line m1 be d2, and the minimum distance from the side of the second recess 1415 to the center line m2 be d4. Then, d1 is greater than d2, and d3 is less than d4 (see FIG. 4). In another embodiment, the bottom of the first recess 1414 may be lower than the top of the second recess 1415, but the length C of the fuse portion must be equal to the minimum distance D between the outer contour of the first recess 1414 and the outer contour of the connection plate 141. That is, d1 < d2, d3 < d4, and C = D (see FIG. 5).

[0048] Referring to FIGS. 1 to 5, in the electrode lead member 140 provided by the present invention, by disposing the first recess 1414 on the connection plate 141, the weight of the connection plate 141 is reduced, and the mass energy density of the battery is improved. Since the second recess 1415 is disposed on the connection plate 141, the weight of the connection plate 141 is further reduced. Further, a fuse portion is formed between the second recess 1415 and the first recess 1414. In this way, when the battery is short-circuited, the connection plate 141 melts at the fuse portion, and the battery is cut off. Thereby, ignition and explosion of the battery due to short circuit are prevented, and overcurrent protection of the connection plate 141 is realized.

[0049] 1 to 6, a cover assembly 130 provided by the present invention includes a cover body 131, a lower insulating member 132, and the above-mentioned electrode lead member 140. The lower insulating member 132 is disposed on one side of the cover body 131 facing the electrode assembly 120, and isolates the cover body 131 from the electrode assembly 120 to electrically insulate them. A through hole is provided in the cover body 141, and an electrode terminal 142 of the electrode lead member 140 penetrates the lower insulating member 132 and is at least partially disposed within the through hole of the cover body 131. At least a portion of the connection plate 141 of the electrode lead member 140 abuts on one side of the lower insulating member 132 remote from the cover body 131.

[0050] 7 and 11, in some embodiments, the shape of the cover body 131 is adapted to the shape of the casing 110. For example, when the casing 110 is a square casing, the cover body 131 is a matching square plate structure. When the casing 110 has other shapes, the shape of the cover body 131 may also be other shapes adapted to the casing 110 accordingly. Optionally, the cover body 131 may be made of a material having a certain hardness and strength, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc. In this way, the cover body 131 is less likely to deform when subjected to extrusion or impact, so that the battery can have higher structural strength and improve safety performance.

[0051] 7 and 8, the shape of the lower insulating member 132 is consistent with that of the cover body 131. The lower insulating member 132 may have an integral structure or a divided structure assembled from various parts. The cover body 131 is usually made of a metal material having a certain hardness and strength, so that if the cover body 131 directly contacts the electrode assembly 120, a direct short circuit may occur in the electrode assembly 120. Therefore, the cover body 131 and the electrode assembly 120 can be insulated from each other by disposing the lower insulating member 132 between the cover body 131 and the electrode assembly 120. The material of the lower insulating member 132 is generally an insulating plastic.

[0052] 2, 7, and 10, since there is no limiting device between the lower insulating member 132 and the cover body 131, the lower insulating member 132 may easily slip out of the cover body 131 during the assembly process of the cover assembly 130. This may affect the assembly accuracy and efficiency. In the present invention, a protrusion 1321 that matches the first recess 1414 is disposed on one side of the lower insulating member 132 facing the connection plate 141 of the electrode lead member 140. The protrusion 1321 is embedded and matches the first recess 1414 on the connection plate 141, thereby positioning the lower insulating member 132 and preventing it from slipping out of place. The shape of the protrusion 1321 is not particularly limited as long as it matches the shape of the first recess 1414. For example, if the first recess 1414 is a square structure, the protrusion 1321 is a matching square protrusion, and if the first recess 1414 is another structure, the protrusion 1321 is another matching structure. It should be noted that the size of the protrusion 1321 should realize the positioning of the lower insulating member 132 without affecting the mating relationship between the components of the cover assembly 130. Therefore, the size of the protrusion 1321 should satisfy the following relationship: h1 is the height of the protrusion 1321, h2 is the depth of the first recess 1414, and h3 is the gap between the transition connection zone 1413 and the lower insulating member 132, and h1≦h2+h3. Here, h3 is the gap generated during the actual assembly process, and preferably h3=0.

[0053] 2 and 8, in order to achieve a better weight-saving effect of the connection plate 141 and a better positioning effect of the lower insulating member 132, two or more first recesses 1414 are usually provided on the connection plate 141. Correspondingly, a number of protrusions 1321 are arranged on the lower insulating member 132. In order to prevent the protrusions 1321 and the first recesses 1414 from being jammed, the protrusions 1321 and the first recesses 1414 are provided with a clearance fit. That is, a certain gap d is provided between the outer contour of the protrusion 1321 and the inner wall of the first recess 1414. The minimum value of d is 0.1 mm, and the maximum value should be such that the movement area of ​​the lower insulating member 132 does not exceed the coverage area of ​​the cover body 131. Such a gap arrangement can prevent the protrusions 1321 from being jammed in the first recesses 1413 during the assembly process, and can also limit the movement range of the lower insulating member 132 to prevent it from coming off the cover body 131.

[0054] 7 and 8, preferably, the protrusion 1321 is provided as a groove on one side facing the cover body 131. That is, the protrusion 1321 includes a bottom and a side, the side is connected to the lower insulating member 132 and extends in a direction away from the cover body 131, and the bottom is connected to one side away from the side cover body 131. By arranging the groove-shaped protrusion 1321, the weight of the lower insulating member 132 can be reduced. The protrusion 1321 may be integrally injection molded with the lower insulating member 132, or may be processed after the lower insulating member 132 is formed. Furthermore, in order to prevent a part of the electrolyte from being accumulated in the groove of the protrusion 1321 when the battery is filled with liquid, a liquid guide hole is provided on the protrusion 1321, and the electrolyte in the groove flows out from the liquid guide hole. The liquid guide hole may be provided on the bottom of the protrusion, on the side, or on both the bottom and the side.

[0055] 7, 8 and 11, the lower insulating member 132 not only insulates the electrode assembly 120 and the cover body 131, but also supports the electrode assembly 120. After the electrode assembly is assembled into the casing and the cover assembly 130 is welded, the internal winding cell of the electrode assembly 120 is in a slightly compressed state. In addition, since it may be in a vibrating environment during the process of loading and use, if the electrode assembly 120 is not sufficiently restrained, the life of the winding cell may be easily affected or a short circuit may occur. Therefore, the structural design of the lower insulating member 132 also needs to ensure that the electrode assembly 120 can be effectively supported to prevent it from moving up and down. For example, a support part 1322 is provided on one side of the lower insulating member 132 away from the cover body 131 to resist the electrode assembly 120. In this way, the support strength of the lower insulating member 131 can be improved to restrain the electrode assembly 120 from moving up and down, and prevent the tab from being torn up and down. The support portion 1322 is a structure that protrudes from the surface of the lower insulating member 132, and may be a cylinder, a prism, a hexahedron, or another structure. The support portion 1322 may be provided at both ends of the lower insulating member 132, or may be provided in the center of the lower insulating member 132. Preferably, the support portion 1322 is provided at both ends and the center of the lower insulating member 132.

[0056] 1 and 7, the cover assembly 100 further includes an upper insulating member 133 and a seal member 134. The upper insulating member 133 and the seal member 134 separate and insulate the electrode terminal 142 of the electrode lead member 140 from the cover body 131. The upper insulating member 133 and the seal member 134 can be made of rubber or other insulating materials. Specifically, each upper insulating member 133 is sleeved on a portion where the electrode terminal 142 protrudes from the cover body 131, and is fixed to one side of the cover body 131 away from the lower insulating member 132. Preferably, each upper insulating member 133 fits with the electrode terminal 142 along the circumferential direction of the electrode terminal 142. For example, an annular groove 1421 is provided around the upper periphery of the electrode terminal 142 protruding from the cover body 131, and a positioning ring protruding in the radial direction is provided on the inner wall of each upper insulating member 133. When each upper insulating member 133 is attached, the positioning ring is embedded in the annular groove 1421, thereby positioning the upper insulating member 133 and the electrode lead member 140. Each seal member 134 is attached at a position close to the connection plate 141 of the electrode terminal 142. For example, an annular boss 1422 protruding from the electrode terminal 142 is provided at the connection portion between the electrode terminal 142 and the connection plate 141, and each seal member 134 is sleeve-connected to the annular boss 1422.

[0057] Referring to FIG. 7, in one embodiment, the cover assembly 130 includes two electrode lead members having opposite polarities, which are designated as a first electrode lead member 143 and a second electrode lead member 144. The first electrode lead member 143 is connected to the positive electrode tab of the electrode assembly 120, and the second electrode lead member 144 is connected to the negative electrode tab of the electrode assembly 120. The first electrode lead member 143 and the second electrode lead member 144 may be disposed at the same end of the battery or at different ends, specifically determined by the tabs of the electrode assembly 120. When the positive electrode tab and the negative electrode tab are distributed at the same end of the electrode assembly 120, the first electrode lead member 143 and the second electrode lead member 144 are located at the same end of the battery. When the positive electrode tab and the negative electrode tab are distributed at different ends of the electrode assembly, the first electrode lead member 143 and the second electrode lead member 144 are located at different ends of the battery corresponding to the positive electrode tab and the negative electrode tab. In the present invention, the positive electrode tab and the negative electrode tab are distributed to the same end of the electrode assembly 120, so that the first electrode lead member 143 and the second electrode lead member 144 are located at the same end of the battery.

[0058] 7, a first through hole is provided at both ends of the cover body 131 for the electrode terminals of the first electrode lead member 143 and the second electrode lead member 144 to pass through. A second through hole is provided at both ends of the lower insulating member 132 for the electrode terminals 142 of the first electrode lead member 143 and the second electrode lead member 144 to pass through. The electrode terminals 142 of the first electrode lead member 143 and the second electrode lead member 144 pass through the second through hole and the first through hole in order, and are sealed, insulated, and fixed by the upper insulating member 133 on the cover body 131. The connection plates of the first electrode lead member 143 and the second electrode lead member 144 abut against one side of the lower insulating member 132 that is remote from the cover body 131. The lower insulating member 132 is provided with a protrusion 1321 at a position corresponding to the connection plates of the first electrode lead member 143 and the second electrode lead member 144, improving the positioning effect.

[0059] 2 and 7, in order to prevent the first electrode lead member 143 and the second electrode lead member 144 from being connected in the opposite directions, in one embodiment, the first recesses 1414 on the connection plate 141 of the two electrode lead members are configured to be incompatible. That is, the positions or shapes of the first recesses 1411 on the connection plate 141 connected to the first electrode lead member 143 and the second electrode lead member 144 are different, so that the first electrode lead member 143 and the second electrode lead member 144 can be distinguished by their shapes or positions. To be more specific, the first recess 1414 of the first electrode lead member 143 has a first shape, and the first recess 1414 of the second electrode lead member 144 has a second shape, and the first shape is configured to be different from the second shape. For example, the first shape is a square hole and the second shape is a long hole, or the first shape is a through hole and the second shape is a groove. Alternatively, the first recess 1414 of the first electrode lead member 143 is positioned at a first position on the connecting plate 141, and the first recess 1414 of the second electrode lead member 144 is positioned at a second position on the connecting plate 141, with the first position and the second position being located at different positions in the transition connection zone 1413, but this is not particularly limited as long as the polarities of the two electrodes can be distinguished.

[0060] 7 and 11, the cover assembly 130 further includes a pressure release mechanism 135, which releases the internal pressure or temperature of the secondary battery 100 when the internal pressure or temperature of the secondary battery 100 reaches a predetermined value. Illustratively, the pressure release mechanism 135 is located between the first electrode lead member 143 and the second electrode lead member 144. The pressure release mechanism 135 may be a component such as a blast valve, a blast disk, an air valve, a pressure release valve, or a safety valve.

[0061] Referring to FIG. 11, the casing 110 of the secondary battery 100 provided by the present invention includes an end wall and a side wall disposed around the end wall, and a stable sealing and electrical connection relationship is formed between the end wall and the side wall. The connection between the end wall and the side wall can be achieved in various ways, such as one-piece stamping, one-piece casting, or split welding. The side wall may be formed in a square shape around the end wall, or along any other closed loop contour that fits with the end wall. In this embodiment, the end wall is rectangular, and the side wall is disposed in a circular direction along four sides of the end wall, and a square opening is formed at one end of the side wall away from the end wall. A receiving cavity is formed within the casing 110 surrounded by the end wall and the side wall, and is used to receive the electrode assembly 120, the electrolyte (not shown), and other necessary components of the battery. Specifically, the size of the casing 110 can be determined according to the specific size of the electrode assembly 120. The casing 110 can be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloys, etc. To prevent the casing 110 from rusting during long-term use, the surface of the casing 110 may be plated with a layer of an anti-rust material, such as metallic nickel.

[0062] Referring to FIG. 11, the electrode assembly 120 is housed in a casing 110, and the electrode assembly 120 is a component in a secondary battery 100 where an electrochemical reaction occurs. One or more electrode assemblies 120 may be included in the casing 110. The electrode assembly 120 includes a body portion and a tab connected to the body portion. The electrode assembly 120 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material, and the positive electrode active material is applied to the surface of the positive electrode current collector. The positive electrode current collector includes a coated zone that is coated with the active material and an uncoated zone that is not coated with the active material, and the uncoated zone is wound to form a positive electrode tab of the electrode assembly. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material, and the negative electrode active material is applied to the surface of the negative electrode current collector. The negative electrode current collector includes a coated zone coated with active material and an uncoated zone not coated with active material, and the uncoated zone is wound to form the negative electrode tab of the electrode assembly. Taking a lithium-ion secondary battery as an example, the material of the positive electrode current collector may be aluminum. The positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganate. The material of the negative electrode current collector may be copper. The negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon or silicon. The material of the separator may be polypropylene (PP) or polyethylene (PE), etc. To protect and insulate the cell, the electrode assembly 120 may be covered with an insulating film, and the insulating film can be made of PP, PE, PET, PVC, or other polymer materials. In the present invention, the electrode assembly 120 includes a first tab and a second tab facing the opening of the casing, the first tab and the second tab having opposite electrical properties, i.e., one is a positive tab and the other is a negative tab.The cover assembly 130 seals and blocks the opening of the casing 110, and the first electrode lead member 143 and the second electrode lead member 144 are connected by welding to the first tab and the second tab, respectively.

[0063] Referring to FIG. 12, the present invention further provides an electronic device 10. The electronic device 10 includes a working unit 11 and a battery group. The working unit 11 is electrically connected to the battery group to obtain power energy support. The battery group includes a box and a plurality of secondary batteries 100 provided by the present invention. The plurality of secondary batteries 100 are arranged in the box and connected in series, parallel, or a mixed manner of series and parallel. It should be noted that, in addition to the secondary battery 100 provided by the present invention, the battery group can also include a thermal management system, a circuit board, and other components of the battery group, which will not be described one by one here.

[0064] For example, the electronic device 10 is a vehicle. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or a range-extended vehicle, etc., but the present invention is not limited thereto. The working unit 11 is a vehicle body, and the battery group is disposed at the bottom of the vehicle body, providing power energy support for driving the vehicle or operating electrical components in the vehicle.

[0065] In other embodiments, the electronic device may be a mobile phone, a mobile device, a laptop, a ship, a spaceship, an electric toy, an electric tool, etc. The spaceship may be an airplane, a rocket, a space shuttle, a spaceship, etc. The working part may be a unit part that can obtain the electric energy of the battery group to perform a corresponding work, such as a blade rotation unit of a fan, a dust collection working unit of a vacuum cleaner, etc. The electric toy may be a fixed or mobile electric toy, such as a game console, an electric toy car, an electric toy ship, an electric toy airplane, etc. The electric tool may be a metal cutting electric tool, a polishing electric tool, an assembly electric tool, a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, an electric planer, etc. The above-mentioned electronic device is not particularly limited in the embodiment of the present invention.

[0066] In the present invention, the electrode lead member is provided with a first recess recessed in the thickness direction in the connection plate, so that the thickness of the connection plate is reduced in this zone. By arranging the first recess, not only the weight of the connection plate is reduced, but also it can be matched with the protrusion provided on the lower insulating member of the cover assembly. In this way, the positioning is achieved, and the lower insulating member can be prevented from being misaligned and affecting the assembly. By arranging the second recess recessed in the thickness direction on the connection plate, the weight of the connection plate can be further reduced. Furthermore, since a fuse part is formed between the second recess and the first recess, the overcurrent protection of the connection plate is realized. Since the protrusion on the lower insulating member of the cover assembly is installed in the cavity structure, the weight of the lower insulating member can be reduced. A liquid guide hole is provided on the protrusion to prevent the electrolyte from being stored in the cavity of the protrusion. Therefore, since some practical problems in the prior art are effectively overcome, the present invention shows high utility value and significance of use.

[0067] The above-described embodiments are merely examples for illustrating the principles and effects of the present invention, and are not intended to limit the present invention. Those skilled in the art may modify or change the above-described embodiments without departing from the spirit and scope of the present invention. Therefore, any equivalent modifications or changes made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the present invention. [Industrial Applicability]

[0068] The electrode lead member, cover assembly, secondary battery, and electronic device of the present invention can be applied to the field of new energy vehicles. [Explanation of symbols]

[0069] 10 Electronic equipment 11 Working section 100 Secondary battery 110 Casing 120 Electrode Assembly 130 Cover Assembly 131 Cover body 132 Lower insulating member 1321 Protrusion 1322 Support part 133 Upper insulating member 134 Sealing material 135 Pressure Relief Mechanism 140 Electrode lead member 141 Connection plate 1411 Terminal Connection Zone 1412 Tab Connection Zone 1413 Transitional Connectivity Zone 1414 First recess 1415 Second recess 142 Electrode Terminal 1421 Circular groove 1422 Circular boss 143 First electrode lead member 144 Second electrode lead member

Claims

1. a connection plate including a terminal connection zone, a tab connection zone, and a transition connection zone for connecting the terminal connection zone and the tab connection zone; an electrode terminal connected to the terminal connection zone; an electrode lead member including: at least one first recess provided in the transition connection zone, the at least one first recess recessed in a thickness direction of the connection plate; and an inner contour of a side wall of the at least one first recess positioned inside an outer contour of a side wall of the connection plate.

2. The electrode lead member according to claim 1 , wherein a projection of the at least one first recess along the thickness direction is located outside the tab connection zone.

3. 2. The electrode lead member according to claim 1, wherein the at least one first recess is recessed in a first direction, the first direction being directed from one side of the connection plate to which the electrode terminal is connected to the other side of the connection plate.

4. The electrode lead member according to claim 1 , wherein the at least one first recess is a through hole that penetrates the connection plate in the thickness direction.

5. 2. The electrode lead member according to claim 1, wherein the thickness of the connection plate is h, the minimum distance between the inner contour of the side wall of the at least one first recess and the outer contour of the side wall of the connection plate is D, and D satisfies 0.5h≦D≦1.5h.

6. 2 . The electrode lead member according to claim 1 , wherein a minimum distance between the inner contour of the side wall of the at least one first recess and the outer contour of the side wall of the connecting plate is D, where 0≦D≦10 mm.

7. 2. The electrode lead member according to claim 1, wherein a second recess is provided at a position extending in a second direction of the connection plate, the second direction being directed from the terminal connection zone to the tab connection zone, the second recess is recessed in the thickness direction of the connection plate, and a fuse portion is formed between the second recess and the at least one first recess.

8. 8. The electrode lead member according to claim 7, wherein the at least one first recess is provided in each transition connection zone on one side of the terminal connection zone, the second recess is disposed at a position away from the terminal connection zone of the connection plate between the at least one first recess on both sides, the at least one first recess has a polygonal column structure, the second recess has a polygonal column structure, one side of the second recess away from the terminal connection zone penetrates one side of the connection plate, and the fuse portion is formed at a vertex between the at least one first recess and the second recess.

9. 9. The electrode lead member according to claim 8, wherein the at least one first recess is a through hole penetrating the connection plate in the thickness direction, the second recess is a through hole penetrating the connection plate in the thickness direction, the length of the fuse portion is C, a minimum distance between an outer contour of the at least one first recess and an outer contour of the connection plate is D, and a width of the connection plate at which the tab connection zone is located is A, and C+D<A.

10. The electrode lead member according to claim 7 , wherein the second recess is a through hole that penetrates the connection plate in the thickness direction.

11. 2. The electrode lead member according to claim 1, wherein the connection plate and the electrode terminal are of one piece structure, or the terminal connection zone is higher in the thickness direction than the transition connection zone, and the electrode terminal and the connection plate are made of different materials.

12. 12. The electrode lead member according to claim 11, wherein the material of the electrode terminal is a metal containing aluminum, the material of the connection plate is a metal containing copper, and the electrode terminal and the terminal connection zone are connected by friction welding.

13. A cover body having a through hole; a lower insulating member disposed on one side of the cover body; The lower insulating member according to any one of claims 1 to 12, the electrode terminal of the electrode lead member penetrates the lower insulating member and is at least partially disposed within the through hole, and at least a portion of the connection plate of the electrode lead member abuts one side of the lower insulating member away from the cover body.

14. The cover assembly according to claim 13, wherein a protrusion that matches with the at least one first recess of the electrode lead member is provided on one side of the lower insulating member facing the connection plate, and the protrusion is embedded and matches with the at least one first recess.

15. The cover assembly of claim 13, wherein each of the terminal connection zones on one side of the transition connection zone is provided with the at least one first recess.

16. The height of the protrusion is h １ and the depth of the at least one first recess is h ２ and the gap between the transition connection zone and the lower insulating member is h ３ and h １ , h ２ , and h ３ But, １ ≦h ２ +h ３ The cover assembly according to claim 14, wherein the following is satisfied:

17. The cover assembly of claim 14, wherein a gap d is provided between the protrusion and an inner wall surface of the at least one first recess, the gap d being d≧0.1 mm, and the gap d ensures that the movement area of ​​the lower insulating member does not exceed the coverage range of the cover body.

18. The cover assembly of claim 14, wherein the protrusion is a groove on one side facing the cover body.

19. 19. The cover assembly of claim 18, wherein the protrusion includes a bottom and a side, the side being connected to the lower insulating member and extending in a direction away from the cover body, the bottom being connected to one side of the side away from the cover body, and a liquid guide hole being provided in the bottom and / or the side.

20. The cover assembly of claim 13, wherein the cover assembly includes a first electrode lead member and a second electrode lead member, and a first recess in the connection plate of the first electrode lead member and a first recess in the connection plate of the second electrode lead member are not interchangeable.

21. 21. The cover assembly of claim 20, wherein the first recess of the first electrode leading member has a first shape and the first recess of the second electrode leading member has a second shape, the first shape being different from the second shape.

22. 21. The cover assembly of claim 20, wherein the first recess of the first electrode lead member is disposed at a first position on the connection plate and the first recess of the second electrode lead member is disposed at a second position on the connection plate, the first position and the second position being located at different positions of the transition connection zone.

23. A casing; an electrode assembly contained within the casing and including a body portion and a tab connected to the body portion; The cover assembly according to any one of claims 13 to 22; the tab and the electrode lead member of the electrode assembly are connected at the tab connection zone, and the cover body of the cover assembly covers an opening of the casing.

24. An electronic device comprising the secondary battery according to claim 23.

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