Full-tab battery overcurrent structure and battery

Abstract

The utility model provides a full-tab battery overcurrent structure and a battery, and belongs to the technical field of new energy batteries. The full-tab battery over-current structure comprises a roll core and an over-current assembly, wherein at least one side of the roll core is provided with a full-tab over-current surface. The overcurrent assembly comprises a current collecting plate and a hot melting welding piece, the current collecting plate comprises a first welding surface and a second welding surface which are opposite to each other, the first welding surface is used for being welded with a battery pole, the hot melting welding piece is arranged between the second welding surface and the full-tab overcurrent surface, and the melting point range of the hot melting welding piece is 90-120 DEG C. By adopting the full-tab battery overcurrent structure and forming the battery, the problem that the electrical performance and the safety performance of the battery are influenced by the defect of a welding mode between a roll core and a collector plate in the prior art can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of new energy batteries, in particular to a full-tab battery overcurrent structure and a battery. Background Art

[0002] When large-sized cylindrical lithium / sodium batteries are charged and discharged at high rates, the temperatures at the positive and negative tabs are the highest, creating a bottleneck for fast charging. To improve the charging efficiency of new energy batteries, the ends of the positive and negative current collectors can be transformed into full-tab end faces that enable surface contact. By connecting the current collectors to the current collecting plates and the positive and negative electrode covers, a stable full-tab conductive structure is formed. This changes the current transmission method between the current collectors and the positive and negative electrodes from traditional line transmission to surface transmission, significantly increasing the current conduction area and current handling capacity, reducing the battery's internal resistance and heat generation, and achieving safe and fast charging.

[0003] In related technologies, the collector plate, located between the full-tab end face of the winding core and the top-cap terminal, is typically connected to the full-tab end face using laser welding. However, laser welding often produces thin, linear weld marks with a small surface area. This results in a small flow area between the collector and the plate, high internal resistance, and increased heat generation during charging and discharging, affecting the battery's electrical and safety performance and hindering the full-tab advantage of the battery. Utility Model Content

[0004] The present invention provides a full-tab battery overcurrent structure and battery, which can solve the problem in the prior art that defects in the welding method between the winding core and the current collecting plate affect the battery's electrical performance and safety performance. The technical solution is as follows:

[0005] In a first aspect, an embodiment of the present invention provides a full-tab battery overcurrent structure, comprising: a winding core and a overcurrent component,

[0006] At least one side of the winding core is provided with a full-electrode lug flow surface;

[0007] The current collecting assembly includes a current collecting plate and a hot melt welding plate. The current collecting plate includes a first welding surface and a second opposite welding surface. The first welding surface is used for welding to the battery pole. The hot melt welding plate is arranged between the second welding surface and the full-tab current passing surface. The melting point of the hot melt welding plate ranges from 90 to 120°C.

[0008] Optionally, a welding boss is protruding from the first welding surface, and a top surface of the welding boss is parallel to the first welding surface.

[0009] Optionally, a first liquid injection hole is provided on the current collecting plate, and a second liquid injection hole matching the first liquid injection hole is provided on the hot melt welding sheet.

[0010] Optionally, a plurality of the first liquid injection holes are provided, and the plurality of the first liquid injection holes are arranged in a circular array.

[0011] Optionally, the hot melt welding sheet is a bismuth-based alloy sheet.

[0012] Optionally, the current collecting plate and the soldering sheet are fixed by reflow soldering or wave soldering.

[0013] In the second aspect, an embodiment of the utility model further provides a battery, comprising the full-tab battery overcurrent structure described in the first aspect, and also comprising a shell and a top cover, wherein the winding core and the overcurrent assembly are installed in the shell and are covered and closed by the top cover, a pole is provided through the top cover, a lower plastic is provided under the top cover, the lower plastic is in contact with the first welding surface, and the pole is welded and fixed to the first welding surface.

[0014] Optionally, the winding core is cylindrical and has the full-tab flow surface on both sides, the shell is cylindrical and has the top cover on both ends, and the flow assembly is provided between the top cover and the corresponding full-tab flow surface.

[0015] The beneficial effects of the technical solution provided by the embodiment of the utility model include at least:

[0016] The full-tab battery overcurrent structure provided by the embodiment of the present invention optimizes and improves the overcurrent structure between the winding core and the upper pole of the shell of the existing full-tab battery, and adopts a combination of a current collecting plate and a hot melt welding plate for overcurrent connection. A hot melt welding plate with a melting point of 90 to 120°C is used to weld the current collecting plate to the winding core. During assembly, the hot melt welding plate is melted by heating, and after cooling, the second welding surface of the current collecting plate is integrally welded to the full-tab overcurrent surface of the winding core. Compared with traditional laser welding, the welding area between the winding core and the current collecting plate is greatly increased, the overcurrent capacity of the winding core is increased, the internal resistance of the battery is reduced, the fast charging capability of the battery is improved, and the safety risks during fast charging and overcharging of the battery are reduced. At the same time, increasing the welding area between the winding core and the current collecting plate can also improve the welding strength, allowing the battery to withstand various more stringent vibration tests. This effectively solves the problem in the prior art that the defects in the welding method between the winding core and the current collecting plate affect the electrical performance and safety performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a cross-sectional schematic diagram of the full-tab battery overcurrent structure provided by an embodiment of the present utility model;

[0019] Figure 2 This is a structural diagram of a current collecting plate provided by an embodiment of the present utility model;

[0020] Figure 3 This is a schematic structural diagram of a hot melt welding sheet provided by an embodiment of the present utility model;

[0021] Figure 4 It is an exploded view of the structure of the battery provided by the embodiment of the present utility model.

[0022] In the figure: 1-winding core; 1a-full-electrode lug flow surface; 2-flow assembly; 3-housing; 4-top cover; 21-collecting plate; 22-hot-melt welding sheet; 41-pole; 42-lower plastic; 211-first welding surface; 212-second welding surface; 213-welding boss; 214-first injection hole; 221-second injection hole. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] Figure 1 This is a cross-sectional schematic diagram of the full-tab battery overcurrent structure provided by an embodiment of the present utility model; Figure 2 This is a structural diagram of a current collecting plate provided by an embodiment of the present utility model; Figure 3 This is a schematic structural diagram of a hot melt welding sheet provided by an embodiment of the present utility model; Figure 4 This is an exploded view of the structure of the battery provided by the embodiment of the present utility model. Figures 1 to 4 As shown, an embodiment of the present invention provides a full-tab battery overcurrent structure, including a winding core 1 and an overcurrent component 2.

[0025] At least one side of the winding core 1 is provided with a full-tab current flow surface 1a. The current flow assembly 2 includes a current collecting plate 21 and a heat-melting plate 22. The current collecting plate 21 includes a first welding surface 211 and a second welding surface 212 opposite to each other. The first welding surface 211 is used for welding to the battery pole. The heat-melting plate 22 is provided between the second welding surface 212 and the full-tab current flow surface 1a. The melting point of the heat-melting plate 22 is between 90 and 120°C.

[0026] In an embodiment of the present invention, the first welding surface 211 of the current collecting plate 21 is welded to the end of the upper terminal post located inside the battery housing using a conventional welding connection method, while the opposite second welding surface 212 is used as a whole to be welded to the full-tab current flow surface 1a at the end of the winding core. By providing a hot melt welding sheet 22 with a melting point range of 90 to 120°C on one side of the second welding surface 212, after the entire battery is installed in place, the side of the hot melt welding sheet 22 away from the second welding surface 212 is in close contact with the full-tab current flow surface 1a. At this time, the entire battery is heated by a heating source, causing the hot melt welding sheet 22 to reach its melting point and melt. The battery is then cooled, and the melted hot melt welding sheet 22 cools and solidifies, thereby achieving the integral welding of the second welding surface 212 of the current collecting plate 21 to the full-tab current flow surface 1a. It should be noted that in the embodiment of the present invention, the melting point of the hot melt welding sheet 22 is set within the range of 90-120°C. This is primarily due to the fact that the closed-cell temperature of the diaphragm in the winding core 1 is approximately 130°C. It is important to avoid damaging the structure and performance of the diaphragm in the winding core 1 due to the hot melt welding sheet 22 melting too high during the welding process. On the other hand, using a hot melt welding sheet 22 within the aforementioned melting point range to weld the current collecting plate 21 to the winding core 1 can also function like a fuse. When a thermal runaway accident occurs during battery use, causing an abnormal temperature rise, and the internal battery temperature exceeds the melting point of the hot melt welding sheet 22, the hot melt welding sheet 22 automatically melts, disconnecting the current collecting plate 21 from the winding core 1 and automatically disconnecting the battery internally. This prevents the battery from continuing to operate under abnormal operating conditions, potentially causing a more serious accident.

[0027] The full-tab battery overcurrent structure provided by the present invention optimizes and improves the overcurrent structure between the winding core and the upper terminal of the battery housing. A combination of a current collecting plate 21 and a hot melt weld 22 is used for overcurrent connection. The hot melt weld 22, with a melting point of 90 to 120°C, is used to weld the current collecting plate 21 to the winding core 1. During assembly, the hot melt weld 22 is heated to melt, and after cooling, the second welding surface 212 of the current collecting plate 21 is integrally welded to the full-tab overcurrent surface 1a of the winding core 1. Compared to traditional laser welding, this significantly increases the weld area between the winding core 1 and the current collecting plate 21, increasing the current handling capacity of the winding core 1, reducing the battery's internal resistance, improving the battery's fast charging capability, and reducing the safety risks associated with fast charging and overcharging. Furthermore, increasing the weld area between the winding core 1 and the current collecting plate 21 also improves weld strength, enabling the battery to withstand more stringent vibration tests. The invention effectively solves the problem in the prior art that the defects in the welding method between the winding core and the collecting disk affect the electrical performance and safety performance of the battery.

[0028] Optionally, a welding boss 213 is protruding from the first welding surface 211, and the top surface of the welding boss 213 is parallel to the first welding surface 211. For example, in an embodiment of the present invention, by protruding a raised cylindrical welding boss 213 on the first welding surface 211, the top surface of the welding boss 213 is used to weld to the pole on the top cover during assembly, which facilitates the positioning of the welding position, reduces the overall occupied volume of the current collecting plate 21, and eliminates the need for folding operations to contact the pole above, further improving the assembly stability and convenience of the lithium battery.

[0029] Optionally, a first liquid injection hole 214 is provided on the current collecting plate 21, and a second liquid injection hole 221 matching the first liquid injection hole 214 is provided on the hot melt welding sheet 22. For example, in an embodiment of the present utility model, a plurality of first liquid injection holes 214 are provided, and the plurality of first liquid injection holes 214 are arranged in a circular array. The current collecting plate 21 is circular as a whole, and four circular first liquid injection holes 214 are evenly punched outward along the axis. Correspondingly, a second liquid injection hole 221 is also coaxially punched out at the corresponding position on the adjacent hot melt welding sheet 22. This facilitates the electrolyte injected from the top to flow through the first liquid injection hole 214 and the second liquid injection hole 221 to infiltrate the winding core 1 below after the battery is assembled, thereby avoiding blockage and improving the infiltration efficiency.

[0030] Optionally, the hot melt solder sheet 22 is a bismuth-based alloy sheet. For example, in the present embodiment, after the battery is welded to the hot melt solder sheet 22, the baking temperature must not exceed the melting point of the hot melt solder sheet 22, such as during the dewatering process. Otherwise, the solder joint will fail. For this reason, the hot melt solder sheet 22 is preferably a low-melting-point alloy, such as a bismuth (Bi)-based alloy. By controlling the types and proportions of other elements in the bismuth-based alloy, the melting point of the alloy solder sheet can be kept within the range of 90-120°C.

[0031] Optionally, the current collecting plate 21 and the soldering piece are fixed by reflow soldering or wave soldering.

[0032] like Figure 4 As shown, the embodiment of the present invention also provides a battery, including Figures 1 to 3The illustrated full-tab battery flow structure also includes a housing 3 and a top cover 4. The winding core 1 and flow assembly 2 are installed within the housing 3 and sealed by the top cover 4. A terminal post 41 is provided through the top cover 4. A lower plastic 42 is provided below the top cover 4. The lower plastic 42 abuts against a first welding surface 211, and the terminal post 41 is welded to the first welding surface 211. The full-tab battery flow structure provided by the present invention is used to form a single lithium battery. It optimizes and improves the flow structure between the winding core and the upper terminal post of the housing of existing full-tab batteries, utilizing a combination of a current collecting plate 21 and a heat-melting plate 22 for flow connection. The heat-melting plate 22, with a melting point of 90 to 120°C, welds the current collecting plate 21 to the winding core 1. During assembly, the heat-melting plate 22 is heated to melt, and after cooling, the second welding surface 212 of the current collecting plate 21 is integrally welded to the full-tab flow surface 1a of the winding core 1. Compared to traditional laser welding, this significantly increases the weld area between the core 1 and the current collecting disc 21, increasing the core 1's current handling capacity, reducing the battery's internal resistance, improving the battery's fast-charging capabilities, and reducing the safety risks of fast-charging and overcharging. Furthermore, increasing the weld area between the core 1 and the current collecting disc 21 also improves weld strength, enabling the battery to withstand more stringent vibration tests. This effectively addresses the existing issue of battery electrical and safety performance being affected by defects in the welding method between the core and the current collecting disc.

[0033] Optionally, the winding core 1 is cylindrical and is provided with full-tab flow surfaces 1a on both sides, the shell 3 is cylindrical and is provided with top covers 4 at both ends, and a flow assembly 2 is provided between the top covers 4 and the corresponding full-tab flow surfaces 1a. For example, in an embodiment of the present invention, the cylindrical winding core 1 is installed in a cylindrical shell 3, and both sides of the shell 3 are covered with top covers 4 provided with poles 41, corresponding to the form of a cylindrical lithium battery. The poles 41 on the top covers 4 on both sides correspond to the positive and negative poles of the battery respectively, and the flow assembly 2 provided by the embodiment of the present invention is used to connect the poles 41 to the positive and negative flow surfaces of the internal winding core 1. Compared with traditional laser welding, the pass rate and production efficiency of the process can be greatly improved, the cost can be reduced, and it is conducive to the industrialization of cylindrical full-tab batteries.

[0034] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the present invention belongs. The terms "first", "second" and similar words used in the specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "include" or "comprising" mean that the elements or objects appearing before "include" or "comprising" include the elements or objects listed after "include" or "comprising" and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper", "lower", "left", and "right" are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] The above description is only an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A full-tab battery overcurrent structure, characterized in that: include: The winding core (1) and the flow-through component (2) At least one side of the winding core (1) is provided with a full-tab flow surface (1a); The current collecting assembly (2) comprises a current collecting plate (21) and a hot melt welding sheet (22), wherein the current collecting plate (21) comprises a first welding surface (211) and a second welding surface (212) opposite to each other, wherein the first welding surface (211) is used for welding to a battery pole, and the hot melt welding sheet (22) is arranged between the second welding surface (212) and the full-tab current passing surface (1a), and the melting point of the hot melt welding sheet (22) ranges from 90 to 120°C.

2. The full-tab battery overflow structure according to claim 1, characterized in that: A welding boss (213) is protruding from the first welding surface (211), and the top surface of the welding boss (213) is parallel to the first welding surface (211).

3. The full-tab battery overflow structure according to claim 1, characterized in that: The collecting plate (21) is provided with a first liquid injection hole (214), and the hot melt welding sheet (22) is provided with a second liquid injection hole (221) matching the first liquid injection hole (214).

4. The full-tab battery overflow structure according to claim 3, characterized in that: A plurality of the first liquid injection holes (214) are provided, and the plurality of the first liquid injection holes (214) are arranged in a circular array.

5. The full-tab battery overflow structure according to claim 1, characterized in that: The hot melt welding sheet (22) is a bismuth-based alloy sheet.

6. The full-tab battery overflow structure according to claim 1, characterized in that: The current collecting plate (21) and the soldering sheet are fixed by soldering in a reflow soldering or wave soldering manner.

7. A battery comprising the full-tab battery overflow structure according to any one of claims 1 to 6, characterized in that: The invention also includes a shell (3) and a top cover (4); the winding core (1) and the current overflow assembly (2) are installed in the shell (3) and are covered and sealed by the top cover (4); a pole (41) is provided through the top cover (4); a lower plastic (42) is provided below the top cover (4); the lower plastic (42) is in contact with the first welding surface (211); and the pole (41) is fixed to the first welding surface (211) by welding.

8. The battery according to claim 7, characterized in that The winding core (1) is columnar, and the full-tab flow surfaces (1a) are provided on both sides; the shell (3) is cylindrical, and the top cover (4) is provided at both ends; the flow assembly (2) is provided between the top cover (4) and the corresponding full-tab flow surface (1a).

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