Pin and battery cell

Abstract

The utility model provides a pin and a battery cell. The pin comprises a pole welding part and a tab welding part, the tab welding part is connected with the pole welding part, the tab welding part is provided with a welding area, and the welding area is provided with a first through hole, so that a tab of a battery cell can penetrate through the first through hole and is welded to the welding area. The first through hole is formed in the welding area of the tab welding part, so that the tab of the battery cell can penetrate through the first through hole and is welded to the welding area, compared with an existing pin outward folding scheme, the redundant length of the tab does not need to be reserved, the phenomenon that the tab is reversely inserted can be avoided, and the structural safety of the battery cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, specifically to pins and battery cells. Background Art

[0002] In related technologies, a battery cell generally includes a core package and pins. The core package leads out tab ears. Currently, for the welding of pins and tab ears, the tab ears are first cut and then ultrasonically welded.

[0003] During the ultrasonic welding process of tab ears and pins, in order to meet a greater error tolerance rate, a sufficient length of tab ears is often reserved to meet the requirements of the ultrasonic welding operation between tab ears and pins. This results in a redundant distance between the welding mark and the electrode plate, and further causes inconsistent orientations of tab ears during the battery cell assembly process, leading to some tab ears being inserted backwards into the bare battery cell, and ultimately causing short circuits, self-discharge problems, etc. due to the contact between the anode and the cathode, posing very serious safety risks. Summary of the Utility Model

[0004] Embodiments of the present application provide a pin and a battery cell, aiming to solve the technical problem in related technologies that the tab ears are too long and prone to being inserted backwards.

[0005] In a first aspect, embodiments of the present application provide a pin, including:

[0006] A pole column welding part;

[0007] A tab ear welding part connected to the pole column welding part. The tab ear welding part is provided with a welding area, and a first through hole is opened in the welding area so that the tab ear of the battery cell can pass through the first through hole and be welded to the welding area.

[0008] In an embodiment, the welding area includes a first welding area and a second welding area, and the first welding area and the second welding area are respectively arranged on both sides of the first through hole.

[0009] In an embodiment, the first welding area is provided with a convex platform structure protruding along a first direction, so that the leading-out part of the tab ear can be accommodated in the convex platform structure and pass through the first through hole to be welded to the second welding area.

[0010] In an embodiment, the height difference between the convex platform structure and the second welding area is y, and the value range of y is (0, d1 + 1 mm], where d1 is the thickness of the leading-out part of the tab ear, and the value range of d1 is (d2 / 150, d2 / 20), where d2 is the thickness of the battery cell.

[0011] In one embodiment, the width of the positive projection of the first through hole along the direction perpendicular to the vertical direction of the tab welding portion is L1, and the value range of L1 is: [d1 + 1 mm, 2*(d3 / 3)], where d1 is the thickness of the lead-out portion of the tab, and d3 is the width of the tab welding portion; and / or,

[0012] The length of the positive projection of the first through hole along the direction perpendicular to the vertical direction of the tab welding portion is L2, and the value range of L2 is (d4, d5), where d4 is the width of the lead-out portion of the tab, and d5 is the length of the tab welding portion.

[0013] In one embodiment, the width of the positive projection of the first through hole along the direction perpendicular to the vertical direction of the tab welding portion is L1, L 1 The value range of which is [d 1 + 1 mm, 2*(d 3 / 3)], where d 1 is the thickness of the lead-out portion of the tab, d 3 is the width of the tab welding portion, and the distance from the center of the positive projection of the first through hole along the direction perpendicular to the vertical direction of the tab welding portion to any one side edge of both sides of the tab welding portion is L 3 , and L1 / 4 ≤ L 3 ≤ L1*3 / 4 mm.

[0014] In one embodiment, the pole column welding portion is provided with a second through hole for fusing protection; and / or

[0015] The tab welding portion is provided with the second through hole, and the second through hole is located between the first through hole and the pole column welding portion.

[0016] In a second aspect, an embodiment of the present application provides an electric core, including a core package, tabs, and pins as described in the first aspect. The tabs are disposed on both end sides of the core package, and the tabs pass through the first through hole and are welded to the welding area.

[0017] In one embodiment, the welding area includes a first welding area and a second welding area, and the tab can be welded to the first welding area, and / or the tab can be welded to the second welding area.

[0018] In one embodiment, the welding area includes a first welding area and a second welding area, and the lead-out portion of the tab is received in the boss structure and passes through the first through hole and is welded to the second welding area.

[0019] The beneficial effects of the embodiments of the present application:

[0020] In an embodiment of the present application, by providing a first through hole in the welding area of the tab welding part, the tab of the battery cell can pass through the first through hole and be welded to the welding area. Compared with the existing external folding solution of the tab, it is not necessary to reserve redundant tab length, which can avoid the reverse insertion of the tab and improve the structural safety of the battery cell. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 is a three-dimensional schematic diagram of a pin provided by an embodiment of the present application;

[0023] Figure 2 is a three-dimensional schematic diagram of a pin with a boss structure provided by an embodiment of the present application;

[0024] Figure 3 is a three-dimensional schematic diagram of the welding of a pin with a boss structure and a tab provided by an embodiment of the present application;

[0025] Figure 4 is a side view schematic diagram of a pin with a boss structure provided by an embodiment of the present application;

[0026] Figure 5 is a three-dimensional schematic diagram of a battery cell provided by an embodiment of the present application;

[0027] Figure 6 is an exploded schematic diagram of a battery cell provided by an embodiment of the present application.

[0028] Reference Signs:

[0029] Battery cell 10, Core package 200, Tab 300, Terminal 400;

[0030] Pin 100, Terminal welding part 101, Tab welding part 102, Welding area 103, First through hole 104, Boss structure 105, Second through hole 106, Detailed Embodiments

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the orientation words such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; and "inner" and "outer" refer to the outline of the device.

[0032] Since in the related art, a battery cell generally includes a core package and pins, and the core package leads out tab ears. Currently, for the welding of the pins and the tab ears, the tab ears are first cut, and then ultrasonic welding is performed. During the ultrasonic welding process of the tab ears and the pins, in order to meet a greater error tolerance rate, a sufficient length of tab ears is often reserved to meet the operation requirements of the ultrasonic welding of the tab ears and the pins. This results in a redundant distance between the welding mark and the electrode plate, and further causes the tab ears to have inconsistent orientations during the battery cell assembly process, resulting in some tab ears being inserted into the bare battery cell, ultimately causing the anode and cathode to come into contact, leading to situations such as short circuit and self-discharge failure, causing very serious safety risks. Therefore, the embodiments of the present application provide a pin and a battery cell. By opening a first through hole in the welding area of the tab ear welding part, the tab ears of the battery cell can pass through the first through hole and be welded to the welding area. Compared with the existing pin outer folding scheme, it does not require reserving redundant tab ear lengths, can avoid the phenomenon of tab ear reverse insertion, and improve the structural safety of the battery cell. For the specific solution, please refer to the following specific description.

[0033] It should be noted that, hereinafter, the terms "battery module", "battery", "battery element", "cell" and "battery pack" may be used interchangeably and may refer to any one of a variety of different rechargeable battery chemistries and configurations, including but not limited to lithium-ion (such as lithium iron phosphate, lithium cobalt oxide, lithium iron phosphate, other lithium metal oxides, etc.), lithium-ion polymer, nickel metal hydride, nickel cadmium, nickel hydrogen, nickel zinc, silver zinc or other battery types / configurations. The term "electric vehicle" is used herein to refer to a fully electric vehicle also known as an EV, a plug-in hybrid vehicle also known as a PHEV, or a hybrid vehicle (HEV), where the hybrid vehicle uses multiple propulsion sources, one of which is an electric drive system. It should be understood that the use of the same reference numerals on multiple figures to refer to the same components or components with equivalent functions, various modifications to the preferred embodiments, general principles and features described herein will be apparent to those skilled in the art. In addition, the figures are only intended to illustrate and not limit the scope of the present application and should not be considered to be drawn to scale.

[0034] Embodiments of the present application are generally applicable to systems employing electric motors, and more specifically but not exclusively, to electric vehicles using polyphase motors (such as induction motors). Electric vehicles use one or more energy storage sources, such as a battery pack, to supply electrical energy to the vehicle. This energy is used at least in part to propel the vehicle. The stored energy can also be used to provide the energy required for other vehicle systems, such as vehicle lighting, zoned heating, ventilation and air conditioning (HVAC) systems, auxiliary control systems (such as sensors, displays, navigation systems, etc.), vehicle entertainment systems (such as radios, DVDs, MP3s, etc.). Conventional electric vehicles include passenger vehicles and vehicles designed to transport goods, examples of which include passenger cars, trucks, electric bicycles and recreational boats. Electric vehicles also include dedicated work vehicles and carts, some of which can incorporate, for example, forklifts, scissor lifts, boom and / or articulating aerial work platforms, street cleaning systems, conveyor belts and pallet handling platforms.

[0035] In this application, the main structural components of the battery cell include a core package, a housing, as well as auxiliary materials and auxiliary components. Among them, the core package includes at least a positive electrode, a negative electrode, a separator, and an electrolyte; the positive electrode is a key component in the battery cell, and its main function is to store and release energy. Commonly used positive electrode materials include lithium cobaltate, lithium manganate, lithium iron phosphate, and ternary materials (polymers of nickel, cobalt, and manganese); the material of the negative electrode is usually a transition metal oxide or a polyanion compound, which has a layered or spinel structure and a relatively low electrode potential. The main role of the negative electrode is to store and release lithium ions; the separator is a thin film with a microporous structure, which is used to separate the positive electrode and the negative electrode, prevent short circuits, and allow lithium ions to pass through. The electrolyte is a liquid inside the battery cell, mainly composed of organic solvents and inorganic salts, and is used to transport lithium ions between the positive electrode and the negative electrode.

[0036] The housing is used to protect the battery cell, prevent mechanical damage and the influence of environmental factors, and at the same time provide the necessary mechanical strength and shape.

[0037] In addition, the battery cell also includes, but is not limited to, tabs, terminal posts, pins, and some other auxiliary material components, such as binders, conductive carbon black, current collectors, and packaging materials.

[0038] Among them, both ends of the pin are welded to the terminal post and the tab respectively to achieve the electrical connection between the tab and the terminal post.

[0039] Specifically, please refer to Figures 1 to 4 where Figure 1 is a three-dimensional structural schematic diagram of the pin provided by the embodiment of this application. The pin 100 specifically includes a terminal post welding part 101 and a tab welding part 102. The tab welding part 102 is connected to the terminal post welding part 101. The tab welding part 102 is provided with a welding area 103, and a first through hole 104 is opened in the welding area 103 so that the tab 300 of the battery cell 10 can pass through the first through hole 104 and be welded to the welding area 103.

[0040] Among them, in order to facilitate the electrical connection between the tab 300 and the terminal post 400, the shape of the pin 100 is related to the position where the tab 300 is led out from the battery cell 10. For example, in this application, the tab 300 is led out from both ends of the battery cell 10, and the terminal post 400 is usually arranged at the top of the battery cell 10. Therefore, the pin 100 needs to extend from one end of the battery cell 10 to the adjacent other end, and there will be a nearly 90° bend in the middle. Therefore, the shape of the pin 100 is similar to an L shape.

[0041] Among them, the terminal post welding part 101 of the pin 100 is used to be welded to the terminal post 400 (not marked in the figure), and the tab welding part 102 is welded to the tab 300.

[0042] For convenience of description, assume that the pin 100 has been welded to the battery cell 10. Then, a welding area 103 is provided on a side surface A of the tab welding portion 102 away from the core package 200. In theory, any area in the side surface A can be the welding area 103.

[0043] Among them, a first through hole 104 is provided in the welding area 103. The function of the first through hole 104 is to facilitate the tab 300 of the battery cell 10 to pass through the first through hole 104 and be welded to the welding area 103.

[0044] In the solution disclosed above in the present application, by providing the first through hole 104 in the welding area 103 of the tab welding portion 102, the tab 300 of the battery cell 10 can pass through the first through hole 104 and be welded to the welding area 103. Compared with the existing solution of folding the pin 100 outward, it does not need to reserve a redundant length for the tab 300, and can avoid the phenomenon of reverse insertion of the tab 300, improving the structural safety of the battery cell 10.

[0045] In some embodiments of the present application, the welding area 103 includes a first welding area and a second welding area, and the first welding area and the second welding area are respectively provided on both sides of the first through hole 104. It can be understood that the first through hole 104 divides the welding area 103 into two areas, namely the first welding area and the second welding area. Among them, the specific positions of the first welding area and the second welding area can be set according to actual needs. For example, the area on the left side of the first through hole 104 is the first welding area, and the area on the right side of the first through hole 104 is the second welding area. Alternatively, the area on the right side of the first through hole 104 is the first welding area, and the area on the left side of the first through hole 104 is the second welding area.

[0046] As Figures 2 - 4 shown, among them, Figure 2 is a three-dimensional schematic diagram of the pin 100 with a boss structure 105 provided in an embodiment of the present application, Figure 3 is a three-dimensional schematic diagram of the welding of the pin 100 with a boss structure 105 and the tab 300 provided in an embodiment of the present application, Figure 4 is a side view schematic diagram of the pin 100 with a boss structure 105 provided in an embodiment of the present application. In some embodiments of the present application, a boss structure 105 protruding along the first direction is provided in the first welding area, so that the lead-out portion of the tab 300 can be accommodated in the boss structure 105 and pass through the first through hole 104 to be welded to the second welding area. Among them, the first direction is the direction away from the core package 200, or the first direction is the direction perpendicular to the tab welding portion 102 and extending along the outer side of the L shape.

[0047] Among them, the lead-out part of the tab 300 refers to the part that leads out the positive and negative electrodes inside the core package 200 through a metal conductor. This design enables the core package 200 to be connected to an external circuit system, thereby realizing the charge and discharge functions. And the lead-out part of the tab 300.

[0048] Specifically, the tab 300 is a metal conductor that leads out the positive and negative electrodes from the battery cell 10. The tab 300 is usually referred to as the "ear" of the core package 200 and plays the role of a contact point during the charge and discharge process.

[0049] Optionally, the positive tab 300 usually uses aluminum (Al) material, while the negative tab 300 uses nickel (Ni) or copper (Cu) material.

[0050] In addition, the inventors of the present application have found through research that the position, number, and size of the tab 300 are related to aspects such as the internal resistance, rate performance, and thermal management of the battery cell 10. Therefore, the position, number, and size of the tab 300 can be set accordingly according to actual needs and are not limited herein.

[0051] Among them, placing the lead-out part of the tab 300 in the boss structure 105 and passing through and welding it to the second welding area from the first through hole 104 can effectively reduce the overall thickness dimension of the welded part 102 of the tab and the tab 300 after welding, save the internal space of the battery cell 10, optimize the overall structure of the battery cell 10, thereby improving the energy density and performance of the unit battery cell 10 and reducing costs.

[0052] Optionally, in order to ensure that the design of the boss structure 105 can effectively reduce the overall thickness dimension of the welded part 102 of the tab and the tab 300 after welding, the height difference between the boss structure 105 and the second welding area can be set as y, and the value range of y is (0, d 1 +1 mm], where d 1 is the thickness of the lead-out part of the tab 300, and the value range of d 1 is (d 2 / 150, d 2 / 20), where d 2 is the thickness of the battery cell 10. It should be noted that the thickness of the battery cell 10 needs to be set according to customer requirements. Therefore, it is not specifically limited herein. Similarly, the thickness of the lead-out part of the tab 300 is related to the thickness of the battery cell 10, and its specific thickness can be set according to actual needs. Similarly, for the features whose specific dimension values are not given in the following text, their specific dimensions can be set according to actual needs and will not be elaborated herein.

[0053] Further, to ensure effective welding of the tab 300 and the tab welding portion 102, the width of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 is L1, and the value range of L1 is [d 1 +1 mm, 2*(d 3 / 3)], where d 1 is the thickness of the lead-out portion of the tab 300, and d 3 is the width of the tab welding portion 102; and / or, the length of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 is L 2 , and the value range of L 2 is (d 4 , d 5 ), where the d 4 is the width of the lead-out portion of the tab 300, and the d 5 is the length of the tab welding portion 102.

[0054] By limiting the relevant dimensions of the first through hole 104 as described above, the present application can effectively ensure that the tab 300 and the tab welding portion 102 of the pin 100 have a suitable welding area, thereby ensuring that the overall performance of the battery cell 10 is not affected.

[0055] Optionally, the width of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 is L1, and the distance from the center of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 to any one of the two side edges of the tab welding portion 102 is L 3 , and L1 / 4 ≤ L 3 ≤ L1*3 / 4 mm. It can be understood that the center of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 refers to the midpoint of the longest width dimension of the first through hole 104. When the shape of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 is a regular figure, the center of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 is also the center of the regular figure (equivalent to the midpoint of the longest width dimension of the first through hole 104); when the shape of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 is an irregular figure, its center refers to the midpoint of the longest width dimension of the first through hole 104.

[0056] Optionally, the shape of the positive projection of the first through hole 104 along the direction perpendicular to the tab welding portion 102 includes, but is not limited to, a square, a rectangle, and an ellipse.

[0057] By defining the position of the first through-hole 104 as described above, the present application can avoid abnormal welding positions between the tab 300 and the welding area 103 caused by unreasonable settings of the first through-hole 104, and effectively ensure the rationality of the distribution of the tab 300 and the welding area 103.

[0058] In some embodiments of the present application, the pole welding portion 101 is provided with a second through-hole 106 for fusing protection; or the tab welding portion 102 is provided with the second through-hole 106, and the second through-hole 106 is located between the first through-hole 104 and the pole welding portion 101.

[0059] Optionally, the pole welding portion 101 is provided with a second through-hole 106 for fusing protection; and the tab welding portion 102 is provided with the second through-hole 106, and the second through-hole 106 is located between the first through-hole 104 and the pole welding portion 101.

[0060] Among them, the relevant dimensions of the second through-hole 106 can be set according to the actual electrical parameter requirements of the battery cell 10, and are not limited herein.

[0061] Based on the pin 100 provided in the present application, the present application further provides a battery cell 10, as Figures 5 - 6 shown, where Figure 5 is a three-dimensional schematic diagram of the battery cell 10 provided by an embodiment of the present application, Figure 6 is an exploded schematic diagram of the battery cell 10 provided by an embodiment of the present application. The battery cell 10 specifically includes a core package 200, tabs 300, and the pins 100 as described above. The tabs 300 are disposed on both end sides of the core package 200, and the tabs 300 pass through the first through-hole 104 and are welded to the welding area 103.

[0062] It should be noted that the tab 300 can be on the positive electrode side or the negative electrode side. Correspondingly, the above-mentioned pin 100 can be disposed on the positive electrode side, or can be disposed on the negative electrode side simultaneously or separately.

[0063] Optionally, the welding area 103 includes a first welding area and a second welding area. The tab 300 can be welded to the first welding area, and / or the tab 300 can be welded to the second welding area.

[0064] Optionally, the welding area 103 includes a first welding area and a second welding area. The lead-out portion of the tab 300 is received in the boss structure 105 and passes through the first through-hole 104 and is welded to the second welding area.

[0065] In an embodiment of the present application, by providing a first through hole 104 in the welding area 103 of the tab welding portion 102, the tab 300 of the battery cell 10 can pass through the first through hole 104 and be welded to the welding area 103. Compared with the existing solution of folding the external pins 100 outward, it is not necessary to reserve a redundant length for the tab 300, which can avoid the phenomenon of reverse insertion of the tab 300 and improve the structural safety of the battery cell 10.

[0066] The above has introduced the embodiments of the present application in detail. Specific examples are used in this text to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A pin, characterized in that: include: Pole welding part; The pole lug welding portion is connected to the pole column welding portion, the pole lug welding portion is provided with a welding area, the welding area is provided with a first through hole, so that the pole lug of the battery cell can be passed through the first through hole and welded to the welding area, the welding area includes a first welding area and a second welding area, the first welding area and the second welding area are respectively arranged on both sides of the first through hole, the first welding area is provided with a boss structure protruding along a first direction, so that the lead-out part of the pole lug can be accommodated in the boss structure, and passed through the first through hole and welded to the second welding area.

2. The pin according to claim 1, characterized in that: The height difference between the boss structure and the second welding area is y, and the value range of y is (0, d1+1mm], where d1 is the thickness of the lead-out part of the tab, and the value range of d1 is (d2 / 150, d2 / 20), where d2 is the thickness of the battery cell.

3. The pin according to claim 1 or 2, characterized in that: The width of the orthographic projection of the first through hole along the direction perpendicular to the electrode tab welding portion is L1, and the value range of L1 is [d1+1mm, 2*(d3 / 3)], wherein d1 is the thickness of the lead-out portion of the electrode tab, and d3 is the width of the electrode tab welding portion; and / or, The length of the orthographic projection of the first through hole along the direction perpendicular to the electrode tab welding portion is L2, and the value range of L2 is (d4, d5), wherein d4 is the width of the lead-out portion of the electrode tab, and d5 is the length of the electrode tab welding portion.

4. The pin according to claim 1 or 2, characterized in that: The width of the orthographic projection of the first through hole along the direction perpendicular to the welding part of the pole lug is L1, and the value range of L1 is [d1+1mm, 2*(d3 / 3)], wherein d1 is the thickness of the lead-out part of the pole lug, d3 is the width of the welding part of the pole lug, and the distance from the center of the orthographic projection of the first through hole along the direction perpendicular to the welding part of the pole lug to the edge of any one side of the welding part of the pole lug is L3, and L1 / 4≤L3≤L1*3 / 4mm.

5. The pin according to claim 1 or 2, characterized in that: The pole welding portion is provided with a second through hole for fuse protection; and / or The pole tab welding portion is provided with the second through hole, and the second through hole is located between the first through hole and the pole welding portion.

6. A battery cell, characterized in that: It comprises a core package, a pole ear and a pin as claimed in any one of claims 1 to 5, wherein the pole ear is arranged at both end sides of the core package, and the pole ear is passed through the first through hole and welded to the welding area.

7. The battery cell according to claim 6, characterized in that: The welding region includes a first welding region and a second welding region, the electrode tab may be welded to the first welding region, and / or the electrode tab may be welded to the second welding region.

8. The battery cell according to claim 7, characterized in that: The welding area includes a first welding area and a second welding area. The lead-out portion of the tab is accommodated in the boss structure and is penetrated through the first through hole and welded to the second welding area.

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