Battery cell, battery, electric device, and battery cell assembly method

Abstract

The application relates to a battery monomer, which comprises a shell, a pole, an electric core and a current collecting disc, a first boss of the pole and a second groove of the current collecting disc are filled with a sealing element formed by solidification of a hot melt element. The sealing element can form a seal between the first boss and the second groove and surround a welding mark, so that the sealing effect between the current collecting disc and the pole can be improved, and electrolyte is not easy to enter the welding mark through the gap between the two. Further, the hot melt element forming the sealing element melts due to heating in the welding process. If the welding causes the welding mark to crack, the melted hot melt element will seep into the crack of the welding mark. After the hot melt element solidifies again, the sealing element formed will fill the crack of the welding mark, so that even if electrolyte enters the welding mark, it will not seep out due to the crack in the welding mark. Therefore, the above-mentioned battery monomer can significantly reduce the risk of liquid leakage. In addition, the application also provides a battery monomer assembling method.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, and in particular to a battery cell, a battery, an electrical device, and a battery cell assembly method. Background Technology

[0002] In the assembly process of cylindrical batteries, the through-welding between the current collector and the terminal is a crucial step. A laser penetrates the surface of the terminal to connect it to the internal current collector. To ensure weld strength, a large and deep weld mark is typically formed between the current collector and the terminal. However, this can easily lead to micro-cracks in the welded area of ​​the terminal and current collector, resulting in leakage. Summary of the Invention

[0003] Therefore, it is necessary to provide a battery cell, battery, and power device that can reduce the risk of leakage in order to address the above problems.

[0004] On one hand, this application provides a battery cell, including a casing, a terminal post, a cell, and a current collector. The terminal post has a first groove and a first annular groove extending circumferentially along the bottom wall of the first groove on the side facing the cell. The first annular groove surrounds a first boss. The current collector has a second boss on the side facing the terminal post. The periphery of the second boss has an annular protrusion, and the annular protrusion surrounds a second groove.

[0005] Wherein, the second boss is inserted into the first groove so that the first boss extends into the second groove and the annular protrusion extends into the first annular groove, a weld mark is formed between the top wall of the first boss and the bottom wall of the second groove, and a seal formed by the curing of a hot melt is filled between the first boss and the second groove.

[0006] In one embodiment, the seal includes a first sealing section located between the top wall of the first boss and the bottom wall of the second groove, and a second sealing section located between the side wall of the first boss and the side wall of the second groove.

[0007] In one embodiment, the first annular groove has a first step protruding toward the battery cell on the side of the first boss near the first boss, and the second sealing section extends to the first step.

[0008] In one embodiment, the periphery of the first boss is formed with a second step that slopes downward toward the side opposite to the battery cell, and the seal extends to the second step.

[0009] In one embodiment, the bottom wall of the second groove is formed by a second annular groove extending circumferentially, and the seal extends into the second annular groove.

[0010] In one embodiment, the top wall of the annular protrusion is in contact with the bottom wall of the first annular groove.

[0011] In one embodiment, a sealing ring is held between the top wall of the annular protrusion and the bottom wall of the first annular groove.

[0012] In one embodiment, the seal is formed of a conductive material.

[0013] In one embodiment, a third groove is provided on the side of the electrode facing away from the battery cell, corresponding to the position of the first protrusion.

[0014] Compared to existing technologies, the above-mentioned battery cells have the following beneficial effects:

[0015] In the aforementioned battery cell, the sealing element forms a seal between the first protrusion and the second groove, surrounding the weld mark. This improves the sealing effect between the current collector and the terminal post, preventing electrolyte from easily entering the weld mark through the gap between them. Furthermore, the hot melt component forming the sealing element melts during welding. If the welding causes cracks in the weld mark, the molten hot melt component will seep into the cracks. After the hot melt component solidifies again, the resulting seal will fill the cracks in the weld mark. Therefore, even if electrolyte enters the weld mark, it will not leak out due to the presence of cracks. Thus, the aforementioned battery cell significantly reduces the risk of leakage.

[0016] On the other hand, this application provides a battery comprising a plurality of battery cells as described in any of the preferred embodiments above.

[0017] In another aspect, this application also provides an electrical device, including a battery cell as described in any of the preferred embodiments above or a battery as described in the embodiments above.

[0018] In addition, this application also provides a method for assembling a single battery cell, including the following steps:

[0019] A pole and a collector plate are provided. A first groove and a first annular groove extending circumferentially along the bottom wall of the first groove are formed on one side of the pole. The first annular groove surrounds a first boss. A second boss is formed on one side of the collector plate. An annular protrusion is formed around the periphery of the second boss. The annular protrusion surrounds a second groove.

[0020] The second boss is inserted into the first groove so that the first boss extends into the second groove and the annular protrusion extends into the first annular groove. A heat-fused component is provided between the side wall of the first boss and the side wall of the second groove.

[0021] A through-weld is performed to form a weld mark between the top wall of the first boss and the bottom wall of the second groove. The hot melt melts during the welding process and solidifies after welding to form a seal that fills the space between the first boss and the second groove.

[0022] In one embodiment, the hot melt element is annular, and the step of setting the hot melt element between the sidewall of the first boss and the sidewall of the second groove is: fitting the hot melt element onto the first boss.

[0023] Compared with existing technologies, the above-mentioned battery cell assembly method has the following advantages:

[0024] During the welding process, the hot-melt component melts. If the welding causes cracks in the weld, the molten hot-melt component will seep into the cracks. After the hot-melt component solidifies again, the resulting seal fills the cracks in the weld, thus preventing further cracking. Furthermore, the resulting seal forms a seal between the first boss and the second groove, surrounding the weld, thereby improving the sealing effect between the current collector and the terminal post. Therefore, the above-described battery cell assembly method can significantly reduce the risk of leakage from the battery cells. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a cross-sectional view of a battery cell in one embodiment of the present invention;

[0027] Figure 2 for Figure 1 A magnified schematic diagram of a local structure in a single battery cell is shown.

[0028] Figure 3 for Figure 1 The diagram shows the structural diagram of the electrode in a single battery cell;

[0029] Figure 4 for Figure 1 The diagram shows the structure of the current collector in the battery cell.

[0030] Figure 5 This is a cross-sectional view of a battery cell in another embodiment of the present invention;

[0031] Figure 6 for Figure 5 A magnified schematic diagram of a local structure in a single battery cell is shown.

[0032] Figure 7 for Figure 5 The diagram shows the structure of the current collector in the battery cell. Detailed Implementation

[0033] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0038] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0039] This invention discloses an electrical device, a battery, and a battery cell. The electrical device includes the battery or the battery cell and is capable of providing electrical energy. The electrical device can be a vehicle, mobile phone, portable device, laptop, ship, spacecraft, electric toy, power tool, energy storage device, amusement equipment, elevator, and lifting equipment, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be carousels, drop towers, etc. This application does not impose any special restrictions on the aforementioned electrical devices.

[0040] For new energy vehicles, the aforementioned batteries can serve as a driving power source, thereby replacing fossil fuels to provide driving power.

[0041] The aforementioned battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells. Multiple battery cells can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system to form a battery pack. The battery management system controls and monitors the operating status of each battery cell. Alternatively, multiple battery cells can first be connected in series and / or parallel, and then connected with a module management system to form a battery module. These battery modules can then be electrically connected in series, parallel, or a combination of series and parallel connections, and together with the battery management system, form a battery pack.

[0042] In this battery pack or module, multiple battery cells can be mounted on supporting structures such as housings, frames, or brackets. The individual battery cells and the battery management system can be electrically connected via busbars, such as relays. The battery cells can be lithium-ion, sodium-ion, or magnesium-ion batteries. Specifically, in this embodiment, the battery cell is a lithium-ion cylindrical battery.

[0043] Please see Figure 1 In one embodiment of the present invention, the battery cell 10 includes a housing 100, a terminal post 200, a cell 300, and a current collector 400.

[0044] The housing 100 has a cylindrical structure, specifically a cylindrical shape, and can be made of aluminum or steel. The electrode post 200 is mounted on the housing 100, and the battery cell 300 and current collector 400 are housed within the housing 100. The housing 100 can be a hollow structure with one open end, through which the battery cell 300 and current collector 400 can be installed, and the opening is sealed by a cover plate (not shown) after assembly. The end wall of the housing 100 away from the opening typically has an electrode post hole (not shown), which allows for the installation of the electrode post 200 and provides a channel for welding the electrode post 200 to the current collector 400. Specifically, the electrode post 200 can be fixed to the housing 100 by riveting or by injection molding. The electrode post 200 and housing 100 can be assembled using the same methods found in existing related technologies, and therefore will not be described further here.

[0045] The battery cell 300 is the core component of the battery cell 10 and is housed within the casing 100. The battery cell 300 is generally formed by winding a positive electrode, a negative electrode, and a separator that acts as an insulator between the positive and negative electrodes. Specifically, in this embodiment, the battery cell is cylindrical, with a positive tab and a negative tab at each end. Typically, the positive tab of the battery cell 300 is electrically connected to the terminal post 200 via a current collector 400, and the negative tab is electrically connected to the casing 100 via a negative current collector (not shown). Therefore, the terminal post 200 and the casing 100 serve as the positive and negative terminals of the battery cell 10, respectively.

[0046] Please refer to the following: Figure 3 The electrode post 200 has a first groove 210 and a first annular groove 220 formed on the side facing the battery cell 300. The first annular groove 220 is formed at the bottom of the first groove 210 and extends circumferentially along the bottom wall of the first groove 210. Moreover, the first annular groove 220 surrounds a first boss 230. Optionally, the cross-section of the first groove 210 is generally circular, the first annular groove 220 is correspondingly annular, and the first boss 230 is correspondingly cylindrical.

[0047] Please refer to the following: Figure 4 A second protrusion 410 is formed on the side of the collector plate 400 facing the pole post 200. An annular protrusion 420 is formed around the periphery of the second protrusion 410, and the annular protrusion 420 surrounds the second groove 430. Correspondingly, the second protrusion 410 is generally cylindrical to match the shape of the first groove 210, the annular protrusion 420 is correspondingly annular, and the cross-section of the second groove 430 is also correspondingly circular.

[0048] During the assembly of the battery cell 10, the positive electrode tab of the cell 300 is first welded to the side of the current collector 400 facing away from the second protrusion 410; then the cell 300 together with the current collector 400 is installed into the housing 100 with the current collector 400 facing the terminal post 200. Next, the current collector 400 is welded to the terminal post 200, thus achieving electrical connection between the cell 300 and the terminal post 200.

[0049] Please refer to the following: Figure 2 The second boss 410 is inserted into the first groove 210, the first boss 230 extends into the second groove 430, and the annular protrusion 420 extends into the first annular groove 220. It can be seen that the opposite sides of the collector plate 400 and the pole post 200 are mutually adapted and inserted, thus playing a preliminary positioning role during assembly and helping to maintain the stability of their relative positions during subsequent welding. Furthermore, a weld mark a1 is formed between the top wall of the first boss 230 and the bottom wall of the second groove 430, thereby achieving the welding of the pole post 200 and the collector plate 400.

[0050] Generally, laser penetration welding is performed on the side of the electrode post 200 facing away from the cell 300 to weld the top wall of the first boss 230 to the bottom wall of the second groove 430 together. Specifically, in this embodiment, a third groove 240 is formed on the side of the electrode post 200 facing away from the cell 300, corresponding to the position of the first boss 230. The third groove 240 can reduce the thickness of the area to be welded on the electrode post 200, thereby reducing the difficulty of laser penetration, thus ensuring that a qualified solder mark a1 can be successfully formed between the top wall of the first boss 230 and the bottom wall of the second groove 430.

[0051] Furthermore, a sealant 500 is filled between the first boss 230 and the second groove 430. The sealant 500 is formed by solidifying a heat-fused component (not shown). During the assembly of the battery cell 10, the heat-fused component is pre-positioned between the sidewalls of the first boss 230 and the second groove 430. The heat-fused component is formed from a material with a low melting point, which can be either a conductive or insulating material. During laser penetration welding, the low-melting-point heat-fused component melts into a liquid or molten state under the high temperature generated by laser welding, thereby flowing and embedding into the gap between the first boss 230 and the second groove 430. After welding is completed and the temperature drops, the heat-fused component will solidify again to form the sealant 500.

[0052] The seal 500 forms a seal between the first boss 230 and the second groove 430, surrounding the solder mark a1, thus improving the sealing effect between the manifold 400 and the electrode post 200, preventing electrolyte from easily entering the solder mark a1 through the gap between them. Specifically, in this embodiment, the formed seal 500 includes two parts: a first sealing section 510 radially distributed along the electrode post 200 and a second sealing section 520 axially distributed along the electrode post 200.

[0053] The first sealing section 510 is located between the top wall of the first boss 230 and the bottom wall of the second groove 430, and can provide a seal between the electrode 200 and the collector plate 400 along the radial direction of the electrode 200. Furthermore, the first sealing section 510 surrounds the solder mark a1. The second sealing section 520 is located between the side wall of the first boss 230 and the side wall of the second groove 430, and can provide a seal between the electrode 200 and the collector plate 400 along the axial direction of the electrode 200. Therefore, the sealing effect between the collector plate 400 and the electrode 200 is significantly improved, effectively preventing electrolyte from entering the solder mark a1 through the gap between them.

[0054] More importantly, the hot melt component forming the seal 500 melts into a liquid or molten state during the laser welding process between the electrode post 200 and the manifold 400. If the welding causes cracks in the weld a1, the molten hot melt component will seep into the cracks in the weld a1. After the hot melt component solidifies again, the resulting seal 500 will fill the cracks in the weld a1. Therefore, even if electrolyte enters the weld a1, it will not seep out due to the presence of cracks in the weld a1.

[0055] Typically, laser welding temperatures reach above 2000℃, and the melting temperature of the aforementioned hot melt component is set to 100℃-250℃, preferably 160℃-250℃. By selecting a hot melt component within the above temperature range, it is possible to ensure that the formed seal 500 remains in a solid state during the normal use of the battery cell 10; on the other hand, it is possible to ensure that the hot melt component is fully melted during the laser welding process.

[0056] Specifically, the melting temperature of the hot melt component is 100℃, 120℃, 140℃, 150℃, 160℃, 165℃, 174℃, 180℃, 200℃, 210℃, 230℃ or 250℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0057] Specifically, in this embodiment, the seal 500 is formed of a conductive material. That is to say, the seal 500 can also conduct electricity, thereby increasing the flow area between the electrode 200 and the manifold 400, improving the flow capacity between the two, helping to reduce the internal resistance at the weld between the electrode 200 and the manifold 400, and greatly reducing the temperature rise.

[0058] More specifically, the aforementioned conductive materials include tin and conductive silicone grease. Tin transforms from a solid to a liquid state at 183°C and exhibits excellent conductivity. The melting temperature of conductive silicone grease is approximately 230°C, and in its molten state, the conductive silicone grease expands in volume due to the increase in molecular size, thus allowing it to expand and better fill the gap between the electrode post 200 and the busbar 400.

[0059] Furthermore, in this embodiment, the top wall of the annular protrusion 420 is in contact with the bottom wall of the first annular groove 220. By ensuring that the top wall of the annular protrusion 420 and the bottom wall of the first annular groove 220 are in contact as close to a gap as possible, it is possible to ensure that the area accommodating the thermoplastic component forms a relatively sealed space. In this way, during laser welding, it is possible to prevent the liquid material generated by the melting of the thermoplastic component from overflowing the top wall of the annular protrusion 420 and falling into the housing 100 along the gap between the first groove 210 and the second protrusion 410, thereby effectively avoiding short-circuit failure of the battery cell 300.

[0060] Furthermore, in this embodiment, a sealing ring 600 is sandwiched between the top wall of the annular protrusion 420 and the bottom wall of the first annular groove 220. The sealing ring 600 forms a third sealing section between the pole post 200 and the collector plate 400, thereby helping to further improve the sealing performance between the pole post 200 and the collector plate 400. Moreover, the sealing ring 600 can more effectively prevent the melted molten material from flowing into the housing 100. The molten material formed after the molten material melts can flow to the sealing ring 600 and fill the gaps on the upper and lower sides of the sealing ring 600.

[0061] Please see Figure 3In this embodiment, a first step 221 protruding towards the battery cell 300 is formed along the circumference of the first boss 230 on the side of the first annular groove 220 near the first boss 230, and the sealing member 500 extends to the first step 221. During laser welding, the first step 221 can further prevent liquid substances generated by the melting of the hot melt from falling into the housing 100. Furthermore, the first step 221 covers the mating surface between the top wall of the annular protrusion 420 and the bottom wall of the first annular groove 220, which can prevent electrolyte from penetrating to the mating surface and entering the solder mark a1, thereby further reducing the risk of leakage.

[0062] Specifically, in this embodiment, a second step 231 is formed on the periphery of the first boss 230, which slopes downward toward the side opposite to the battery cell 300, and the seal 500 extends to the second step 231. In this way, the second sealing section 520 can overlap the second step 231, thereby improving the reliability of its connection with the first sealing section 510, thus helping to further improve the sealing performance between the electrode post 200 and the current collector 400.

[0063] In addition, please see Figures 5 to 7 In another embodiment, the bottom wall of the second groove 430 is formed by a second annular groove 431 extending circumferentially, and the seal 500 extends into the second annular groove 431. Thus, the second sealing section 520 can surround the first sealing section 510, which helps to further improve the sealing performance between the pole post 200 and the manifold 400.

[0064] It should be noted that the other structures and functions in this embodiment are the same as those in the previous embodiments, so they will not be described again here.

[0065] In the aforementioned battery cell 10, the sealing element 500 forms a first sealing section 510 between the top wall of the first protrusion 230 and the bottom wall of the second groove 430, and a second sealing section 520 between the side wall of the first protrusion 230 and the side wall of the second groove 430. The first sealing section 510 surrounds the weld mark a1, thus improving the sealing effect between the current collector 400 and the terminal post 200, preventing electrolyte from easily entering the weld mark a1 through the gap between them. Furthermore, the hot melt forming the sealing element 500 melts during the welding process. If the welding causes cracks in the weld mark a1, the molten hot melt will seep into the cracks in the weld mark a1. After the hot melt solidifies again, the resulting sealing element 500 will fill the cracks in the weld mark a1. Therefore, even if electrolyte enters the weld mark a1, it will not leak out due to the presence of cracks in the weld mark a1. Thus, the aforementioned battery cell 10 can significantly reduce the risk of leakage.

[0066] Furthermore, the present invention also provides a method for assembling battery cells, which can be used for assembling… Figure 1 or Figure 5The battery cell 10 shown. In one embodiment of the present invention, the battery cell assembly method includes the following steps S11 to S13.

[0067] Step S11: Provide a pole post 200 and a collector plate 400. A first groove 210 and a first annular groove 220 extending circumferentially along the bottom wall of the first groove 210 are formed on one side of the pole post 200. The first annular groove 220 surrounds a first boss 230. A second boss 410 is formed on one side of the collector plate 400. An annular protrusion 420 is formed around the periphery of the second boss 410. The annular protrusion 420 surrounds a second groove 430.

[0068] The specific structure of the terminal 200 and current collector 400 has been described in detail above, so it will not be repeated here. It should be noted that before welding the terminal 200 and current collector 400, it is necessary to perform steps such as assembling the terminal 200 and welding the battery cell 300 tabs to the current collector 400, but these are not the focus of this application, so they will not be discussed.

[0069] In step S12, the second boss 410 is inserted into the first groove 210 so that the first boss 230 extends into the second groove 430 and the annular protrusion 420 extends into the first annular groove 220. A heat-fused component is provided between the side wall of the first boss 230 and the side wall of the second groove 430.

[0070] The manifold 400 and the pole post 200 are fitted and plugged into each other on opposite sides, which can play a preliminary positioning role during assembly and help maintain the stability of their relative positions during subsequent welding. The hot melt component can be formed from insulating or conductive materials. Preferably, the hot melt component is formed from a conductive material.

[0071] Step S13: Perform penetration welding to form a weld mark a1 between the top wall of the first boss 230 and the bottom wall of the second groove 430. The hot melt melts during the welding process and solidifies after welding to form a seal 500 that fills the space between the first boss 230 and the second groove 430.

[0072] Laser penetration welding is typically performed on the side of the electrode post 200 facing away from the cell 300 to weld the top wall of the first boss 230 to the bottom wall of the second groove 430. During laser penetration welding, the low-melting-point hot melt material melts into a liquid or molten state under the high temperature generated by the laser welding, thus flowing and embedding into the gap between the first boss 230 and the second groove 430. After welding is completed and the temperature drops, the hot melt material will solidify again to form the seal 500.

[0073] Specifically, the sealing element 500 formed by the curing of the hot melt component comprises two parts: a first sealing section 510 radially distributed along the electrode post 200 and a second sealing section 520 axially distributed along the electrode post 200. The first sealing section 510 is located between the top wall of the first boss 230 and the bottom wall of the second groove 430, and can provide a seal between the electrode post 200 and the collector plate 400 along the radial direction of the electrode post 200. Furthermore, the first sealing section 510 surrounds the solder mark a1. The second sealing section 520 is located between the side wall of the first boss 230 and the side wall of the second groove 430, and can provide a seal between the electrode post 200 and the collector plate 400 along the axial direction of the electrode post 200. Therefore, the sealing effect between the collector plate 400 and the electrode post 200 is significantly improved, and electrolyte is less likely to enter the solder mark a1 through the gap between them.

[0074] More importantly, during the laser welding process between the electrode post 200 and the manifold 400, the hot melt component melts into a liquid or molten state. If the welding causes cracks in the weld mark a1, the molten hot melt component will seep into the cracks in the weld mark a1. After the hot melt component solidifies again, the resulting seal 500 will fill the cracks in the weld mark a1, thereby preventing cracks from forming in the weld mark a1.

[0075] Typically, laser welding temperatures reach above 2000℃, and the melting temperature of the aforementioned hot melt component is set to 100℃-250℃, preferably 160℃-250℃. By selecting a hot melt component within the above temperature range, it is possible to ensure that the formed seal 500 remains in a solid state during the normal use of the battery cell 10; on the other hand, it is possible to ensure that the hot melt component is fully melted during the laser welding process.

[0076] Since the hot melt component in this embodiment is formed of conductive material, the resulting seal 500 can also conduct electricity, thereby increasing the flow area between the pole 200 and the manifold 400, improving the flow capacity between them, helping to reduce the internal resistance at the weld between the pole 200 and the manifold 400, and greatly reducing the temperature rise.

[0077] More specifically, the aforementioned conductive materials include tin and conductive silicone grease. Tin transforms from a solid to a liquid state at 183°C and exhibits excellent conductivity. The melting temperature of conductive silicone grease is approximately 230°C, and in its molten state, the conductive silicone grease expands in volume due to the increase in molecular size, thus allowing it to expand and better fill the gap between the electrode post 200 and the busbar 400.

[0078] Specifically, in this embodiment, the hot melt component is annular. The step of setting the hot melt component between the side wall of the first boss 230 and the side wall of the second groove 430 is: to sleeve the hot melt component on the first boss 230.

[0079] By inserting the second boss 410 into the first groove 210, the annular heat-fused component can be fitted onto the first boss 230, thereby positioning the heat-fused component for easy assembly. Moreover, the annular heat-fused component can flow evenly around the first boss 230 when melting, thus helping to form a seal 500 with a uniform texture.

[0080] In the aforementioned battery cell assembly method, the hot melt component is melted during the welding process. If the welding causes cracks in the weld a1, the molten hot melt component will seep into the cracks in the weld a1. After the hot melt component solidifies again, the resulting seal 500 will fill the cracks in the weld a1, thereby preventing cracks from forming in the weld a1. Moreover, the resulting seal 500 can form a seal between the first boss 230 and the second groove 430 and surround the weld a1, thus improving the sealing effect between the current collector 400 and the terminal post 200. Therefore, the aforementioned battery cell assembly method can significantly reduce the risk of leakage from the battery cell 10.

[0081] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A battery cell, comprising a casing, terminals, a cell, and a current collector, characterized in that, The electrode post has a first groove and a first annular groove extending circumferentially along the bottom wall of the first groove on the side facing the electrode post. The first annular groove surrounds a first boss. The current collector has a second boss on the side facing the electrode post. The periphery of the second boss has an annular protrusion. The annular protrusion surrounds a second groove. Wherein, the second boss is inserted into the first groove so that the first boss extends into the second groove and the annular protrusion extends into the first annular groove, a weld mark is formed between the top wall of the first boss and the bottom wall of the second groove, and a seal formed by the curing of a hot melt is filled between the first boss and the second groove.

2. The battery cell according to claim 1, characterized in that, The seal includes a first sealing section located between the top wall of the first boss and the bottom wall of the second groove, and a second sealing section located between the side wall of the first boss and the side wall of the second groove.

3. The battery cell according to claim 2, characterized in that, The first annular groove has a first step protruding toward the battery cell on the side near the first boss along the circumference of the first boss, and the second sealing section extends to the first step.

4. The battery cell according to claim 2, characterized in that, The periphery of the first boss has a second step that sinks down toward the side opposite to the battery cell, and the seal extends to the second step.

5. The battery cell according to claim 2, characterized in that, The bottom wall of the second groove is formed with a second annular groove extending circumferentially, and the seal extends into the second annular groove.

6. The battery cell according to claim 1, characterized in that, The top wall of the annular protrusion fits into the bottom wall of the first annular groove.

7. The battery cell according to claim 6, characterized in that, A sealing ring is held between the top wall of the annular protrusion and the bottom wall of the first annular groove.

8. The battery cell according to claim 1, characterized in that, The seal is formed from a conductive material.

9. The battery cell according to claim 1, characterized in that, A third groove is formed on the side of the electrode facing away from the battery cell, corresponding to the position of the first protrusion.

10. A battery, characterized in that, It includes multiple battery cells as described in any one of claims 1 to 9 above.

11. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1 to 9 or a battery as described in claim 10.

12. A method for assembling a single battery cell, characterized in that, Including the following steps: A pole and a collector plate are provided. A first groove and a first annular groove extending circumferentially along the bottom wall of the first groove are formed on one side of the pole. The first annular groove surrounds a first boss. A second boss is formed on one side of the collector plate. An annular protrusion is formed around the periphery of the second boss. The annular protrusion surrounds a second groove. The second boss is inserted into the first groove so that the first boss extends into the second groove and the annular protrusion extends into the first annular groove. A heat-fused component is provided between the side wall of the first boss and the side wall of the second groove. A through-weld is performed to form a weld mark between the top wall of the first boss and the bottom wall of the second groove. The hot melt melts during the welding process and solidifies after welding to form a seal that fills the space between the first boss and the second groove.

13. The battery cell assembly method according to claim 12, characterized in that, The hot melt component is annular. The step of setting the hot melt component between the side wall of the first boss and the side wall of the second groove is: to sleeve the hot melt component on the first boss.

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