Battery cell and lithium battery

Abstract

The utility model discloses a kind of electric core and lithium battery, electric core includes several stacks, also includes connecting piece, several stacks are stacked, stack is equipped with tab, tab extends stack, and it is set with the upper end surface of stack at angle, the orientation of the tab of the adjacent pair of stacks is oppositely arranged, the tab of the adjacent pair of stacks and stack form mounting groove jointly, mounting groove is used to set connecting piece, the both ends of connecting piece are respectively connected with the tab of adjacent stack.Electrolytic capacitor includes cover plate, electric core and shell, electric core is arranged in shell, cover plate is covered on shell, and it is formed with shell together to accommodate cavity suitable for accommodating electric core.Electrolytic capacitor in the mounting groove of electric core accommodates the welding structure of tab and connecting piece, so that connecting part is integrated into the overall profile of stack group, so that connecting assembly cannot occupy additional vertical height at the top of electric core group, so as to effectively improve the utilization rate of electric core internal space, also reduce the demand of auxiliary structural member quantity to some extent.

Description

Technical Field

[0001] This utility model relates to the field of new energy power battery technology, and in particular to a battery cell and a lithium battery. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage technologies, lithium-ion power batteries, as core energy components, have received increasing attention for their energy density, safety, and manufacturing costs. During battery manufacturing, the internal electrical connections of the cells, especially the connections between the tabs of multiple stacked cells and the battery cover terminals, are crucial factors determining battery electrical performance, long-term reliability, and production efficiency. This leads to the current mainstream internal connection method of welding using connecting tabs.

[0003] In traditional technology, when processing multi-core battery cells, the tabs of each core are typically grouped together, and the current from these tabs is collected using a connecting piece or busbar. This connecting piece is then soldered to the external terminals on the cover plate. For example, in some cell designs with tabs at both ends, the negative terminal might be connected using a butterfly soldering method, while the connection between the positive tab and the terminal requires a specially designed connecting piece. This process often necessitates the use of relatively complex tooling fixtures to precisely position the tabs and connecting pieces before soldering.

[0004] However, current connection methods or traditional devices have significant problems. First, the assembly process is complex, especially the difficulty in assembling and welding the positive electrode tab and terminals. This not only reduces production efficiency but also challenges the final stability and consistency of the product. Second, traditional connection structures, in order to ensure strength and conductivity, are often large in size, occupying valuable space inside the cell, which contradicts the development trend of power batteries pursuing higher energy density. Furthermore, complex positioning and connection methods also mean a large number of structural components, increasing supply chain management and manufacturing costs. Utility Model Content

[0005] Therefore, it is necessary to provide a battery cell and lithium battery to address the above problems.

[0006] This application provides a battery cell disposed within a housing, comprising a plurality of stacked cores and a connecting piece. Each stacked core is provided with a tab, which extends out of the stacked core and is set at an angle to the upper end face of the stacked core. The tabs of an adjacent pair of stacked cores are oriented opposite to each other, forming a mounting groove together with the stacked cores. The mounting groove is used to house the connecting piece, and both ends of the connecting piece are respectively connected to the tabs of the adjacent stacked cores.

[0007] Optionally, the connecting piece is L-shaped, including a first end and a second end. The first end passes through the mounting groove and is connected to the electrode tab. The second end is used to connect to the cover plate. The plane where the first end is located is set at an angle to the plane where the second end is located.

[0008] Optionally, the connecting piece is bent in the middle, and the plane where the first end is located is parallel to the plane where the second end is located.

[0009] Optionally, the electrode tab and the connecting piece are connected by laser welding.

[0010] Optionally, a plurality of the stacked cores are arranged in pairs, and a pair of stacked cores are folded after being connected to the connecting piece, and the projections of the pair of stacked cores on one side of the stacked cores overlap after being folded.

[0011] Optionally, the connecting piece is an aluminum sheet.

[0012] Optionally, the battery cell is wrapped with an insulating adhesive, which fills the space between the battery cell and the housing.

[0013] This application also provides a lithium battery, including a cover plate, a cell, and a casing. The cell is disposed inside the casing, and the cover plate covers the casing, forming a cavity suitable for accommodating the cell together with the casing.

[0014] Optionally, the cover plate is provided with a terminal for connecting the connecting piece, and the connecting piece and the terminal are connected by laser soldering.

[0015] Optionally, the cover plate and the housing are connected by welding for a sealed connection.

[0016] Compared with the prior art, the technical solution provided in this application has the following advantages:

[0017] In the aforementioned battery cell, when two cells with connecting tabs are joined together, the naturally formed channel or space between them serves as a mounting slot. This mounting slot accommodates the welded structure of the electrode tabs and connecting tabs, integrating the connection portion into the overall outline of the battery cell assembly. This structural design prevents the connecting components from occupying additional vertical height at the top of the cell assembly, thus effectively improving the utilization rate of the internal space of the cell. Furthermore, because this connection method relies on the cooperation of the components themselves, it eliminates the need for additional supports or complex positioning fixtures, thereby reducing the required number of auxiliary structural components. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a lithium battery provided in an embodiment of this application;

[0019] Figure 2A schematic diagram of the connection structure between the electrode tab and the connecting piece of a battery cell provided in an embodiment of this application;

[0020] Figure 3 A schematic diagram of the connection structure of the battery cell, connecting piece, and cover plate provided in an embodiment of this application;

[0021] Figure 4 This is a schematic diagram of the overall structure of the battery cell provided in an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of the battery cell before folding, provided in an embodiment of this application.

[0023] Explanation of reference numerals in the attached figures:

[0024] 100, cover plate; 110, terminal; 200, battery cell; 210, stacked core; 211, electrode tab; 220, connecting piece; 221, first end; 222, second end; 300, housing; 400, insulating coating. Detailed Implementation

[0025] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model 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 full understanding of this utility model. However, this utility model can be implemented 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 this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0026] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0027] 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," 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 utility model according to the specific circumstances.

[0029] See Figures 1 to 3 An embodiment of this utility model provides a battery cell, including a plurality of stacked cores 210 and a connecting piece 220. The plurality of stacked cores 210 are stacked and arranged. Each stacked core 210 is provided with a tab 211. The tab 211 extends out of the stacked core 210 and is arranged at an angle to the upper end face of the stacked core 210. The tabs 211 of an adjacent pair of stacked cores 210 are arranged opposite to each other. The tabs 211 of an adjacent pair of stacked cores 210 and the stacked cores 210 together form a mounting groove. The mounting groove is used to set the connecting piece 220. The two ends of the connecting piece 220 are respectively connected to the tabs 211 of the adjacent stacked cores 210.

[0030] In this embodiment, firstly, the connecting piece 220 is welded to the tab 211 of a single stacked core 210, and then the two stacked cores 210s with the connecting pieces 220 already welded are merged into a single unit. This process improves the grouping method of the tabs 211 and reduces the difficulty of production assembly. Compared to directly setting up and welding the connecting piece 220 between multiple independent stacked cores 210, this modular operation of "welding independently first and then merging" decomposes a complex multi-body welding problem into several simple single-unit welding tasks, greatly simplifying the positioning and welding process and improving the stability and efficiency of the operation.

[0031] In this process, when two stacked cores 210 with connecting tabs 220 are joined together, the naturally formed channel or space between them becomes the mounting groove. This mounting groove accommodates the welded structure of the tabs 211 and the connecting tabs 220, integrating the connection part into the overall outline of the stacked core 210 assembly. This structural design ensures that the connecting component does not occupy additional vertical height at the top of the cell 200 assembly, thereby effectively improving the utilization rate of the internal space of the cell 200. At the same time, because this connection method relies on the cooperation of the components themselves, no additional brackets or complex positioning fixtures are required, which also reduces the need for auxiliary structural components to a certain extent.

[0032] See Figures 3 to 5In one embodiment, the connecting piece 220 is L-shaped, including a first end 221 and a second end 222. The first end 221 passes through a mounting groove and connects to the tab 211, while the second end 222 connects to the cover plate 100. The plane containing the first end 221 forms an angle with the plane containing the second end 222. The L-shaped design of the connecting piece 220 in this embodiment, with the plane containing the first end 221 and the plane containing the second end 222 forming an angle, is a highly functional structure. The mounting groove provides a natural and precise placement position for the horizontal portion (first end 221) of the L-shaped connecting piece 220, avoiding misalignment during welding. Simultaneously, the L-shaped structure allows the other portion of the connecting piece 220 (second end 222) to extend naturally vertically upwards, directly aligning with the welding terminals 110 of the cover plate 100. This greatly simplifies the assembly process, eliminating the need for precise bending operations within the confined space of the battery, thereby significantly reducing the precision requirements and operational difficulty of the tooling equipment, further improving production efficiency and the stability of the final product.

[0033] See Figures 1 to 2 In one embodiment, the connecting piece 220 is bent in the middle, with the plane of the first end 221 parallel to the plane of the second end 222. In this embodiment, the connecting piece 220 is welded to the cover plate 100 before being bent, so that the first end 221 and the second end 222 form a U-shape, that is, the plane of the first end 221 is parallel to the plane of the second end 222. After completing the connection with the cover plate 100, the connecting piece 220 is bent to form a U-shaped structure. This U-shaped bend is the core of the design; it acts like a delicate spring, effectively absorbing the mechanical stress of the battery during charging and discharging thermal cycles and vibrations, thereby protecting the weld joints and significantly improving the long-term reliability and safety of the product. At the same time, this flexible structure formed by "welding before bending" can also perfectly compensate for the manufacturing tolerances between components, ensuring the stability and consistency of the assembly. Finally, from a space utilization perspective, this compact U-shaped structure efficiently "folds" the conductor length necessary for connection, completing electrical connections between different heights with minimal planar projection, thereby improving the utilization rate of the internal space of the cell 200 and creating conditions for increasing battery energy density.

[0034] In one embodiment, the tab 211 and the connecting piece 220 are connected by laser welding. Laser welding achieves a high-precision, high-strength electrical connection with minimal damage to the cell 200. Firstly, the high energy density and small spot size of the laser beam enable instantaneous and concentrated heating. This results in highly precise weld points with a minimal heat-affected zone. This precision is crucial within the compact interior of the battery, effectively preventing excess heat from being conducted to heat-sensitive areas such as the active material or separator of the cell 200, thereby maximizing the protection of the cell 200's electrochemical performance and safety.

[0035] Secondly, laser welding can form a strong and aesthetically pleasing weld, ensuring the mechanical reliability and low-resistance electrical performance of the connection between the tab 211 and the connecting piece 220. A stable connection point with low internal resistance is a fundamental requirement for ensuring the high-current discharge performance of lithium batteries and reducing the generation of unnecessary heat.

[0036] See Figures 3 to 5 In one embodiment, several stacked cores 210 are arranged in pairs. One pair of stacked cores 210 is connected to the connecting piece 220 and then folded in half. The projections of the folded pair of stacked cores 210 on one side of the stacked core 210 overlap. The primary technical effect of this "connect first, then fold" process in this embodiment is that it significantly simplifies the manufacturing process of the multi-stacked core 210 cell 200. On the production line, operators or automated equipment can weld two independent stacked cores 210 to the same connecting piece 220 on a single plane. This open operating environment is much simpler than welding inside already stacked, compact cells 200, greatly reducing the difficulty of alignment and welding.

[0037] Secondly, the folding and overlapping design ensures that the final cell 200 has a high degree of regularity and space utilization. The connecting piece 220 not only serves as an electrical connector but also cleverly acts as a mechanical "hinge," guiding the two stacked cells 210 to fold precisely together. This method effectively eliminates excess gaps between the stacked cells 210, forming a thicker, more compact whole, thus accommodating more active material within the limited casing 300, which is an effective means of improving battery energy density.

[0038] In one embodiment, the connecting piece 220 is an aluminum sheet. In typical lithium-ion batteries, the current collector and the extended tab 211 of the positive electrode are typically made of aluminum. Therefore, using a connecting piece 220, also made of aluminum, allows for welding between the same metals. This avoids problems that can occur when welding dissimilar metals (such as aluminum and copper), such as poor bonding strength, easy formation of brittle compounds, and electrochemical corrosion during long-term use, thus ensuring that the connection point has extremely high mechanical strength and long-term stability.

[0039] Secondly, the use of aluminum sheets in the connector 220 contributes to the battery's lightweight design. Aluminum is a low-density metal, and its weight is significantly lighter than copper for the same volume. In the field of power batteries, where weight and energy density requirements are extremely stringent, using aluminum sheets as connectors can effectively reduce the overall weight of the battery, thus helping to improve its weight-based energy density.

[0040] See Figure 1In one embodiment, the battery cell 200 is wrapped with an insulating adhesive 400, which fills the gap between the battery cell 200 and the casing 300. As a charged component, the battery cell 200 must be effectively isolated from the metal battery casing 300. The insulating adhesive 400 wraps around the battery cell 200 and fills the gap between the battery cell 200 and the casing 300, forming a reliable insulating layer. This effectively prevents the battery cell 200 from contacting the casing 300 due to vibration, impact, or other reasons, thereby avoiding external short circuits and preventing hazards such as overheating and fire. This is a fundamental requirement for battery safety design.

[0041] The insulating adhesive 400 filled between the battery cell 200 and the casing 300 acts like a buffer pad. It absorbs and mitigates mechanical shocks and vibrations experienced by the battery during transportation and use, protecting the internal structure of the battery cell 200 from damage. Simultaneously, it tightly secures the battery cell 200 inside the casing 300, preventing it from shifting, thereby improving the overall mechanical stability and long-term reliability of the battery.

[0042] See Figures 4 to 5 An embodiment of the present invention also provides a lithium battery, including a cover plate 100, a cell 200 and a housing 300. The cell 200 is disposed inside the housing 300, and the cover plate 100 covers the housing 300, together with the housing 300 forming a receiving cavity suitable for accommodating the cell 200.

[0043] See Figure 2 In one embodiment, the cover plate 100 has a terminal 110 for connecting the connecting piece 220. The connecting piece 220 and the terminal 110 are connected by laser welding. The main technical benefits of this design are ensuring the overall sealing, stability, and electrical performance of the battery. First, the cover plate 100 is the gateway between the battery's internal and external environments, and the terminal 110 on it is the current outlet. By laser welding the connecting piece 220 and the terminal 110 together, a connection point with high mechanical strength and stable electrical performance can be formed. This high-quality welding can effectively resist the vibration and impact that the battery may encounter during long-term use, ensuring the long-term reliability of the electrical path.

[0044] Secondly, welding on a component like the cover plate 100, which integrates multiple precision components such as safety valves and insulating parts, requires extremely high process standards. The advantages of laser welding—concentrated energy and a small heat-affected zone—are fully demonstrated here. It can achieve precise welding of the terminals 110 and connecting pieces 220 without damaging other sensitive components on the cover plate 100, thereby ensuring the overall safety performance of the battery.

[0045] In one embodiment, the cover plate 100 and the housing 300 are sealed together by welding. The electrolyte and other chemicals inside a lithium-ion battery are extremely sensitive to the external environment (especially moisture and oxygen). Contact with these substances can trigger side reactions, leading to battery performance degradation, shortened lifespan, and even the generation of gases that pose safety risks. Welding the cover plate 100 and housing 300 together to form a continuous and dense whole creates a completely sealed chamber isolated from the external environment, a prerequisite for ensuring the normal operation of the battery's electrochemical system.

[0046] Secondly, the welded seal also serves as a safety barrier to prevent internal substances from leaking out. Battery electrolytes are typically volatile and flammable; the welded seal effectively prevents leakage to the outside, avoiding potential safety hazards.

[0047] Finally, the welded connection also constitutes the final mechanical structure of the battery. It firmly combines the cover plate 100 and the casing 300, making the entire battery a robust whole that can withstand internal pressure changes as well as vibrations and impacts from the external environment, providing the battery with the necessary structural integrity.

[0048] 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.

[0049] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A battery cell, disposed within a housing (300), comprising a plurality of stacked cores (210), characterized in that, It also includes a connecting piece (220). The stacked core (210) is provided with a tab (211). The tab (211) extends out of the stacked core (210) and is set at an angle with the upper end face of the stacked core (210). The tabs (211) of an adjacent pair of stacked cores (210) are arranged opposite to each other and together with the stacked core (210) form a mounting groove. The mounting groove is used to set the connecting piece (220). The two ends of the connecting piece (220) are respectively connected to the tabs (211) of the adjacent stacked cores (210).

2. The battery cell according to claim 1, characterized in that, The connecting piece (220) is L-shaped and includes a first end (221) and a second end (222). The first end (221) passes through the mounting groove and is connected to the tab (211). The second end (222) is used to connect the cover plate (100). The plane of the first end (221) and the plane of the second end (222) are set at an angle.

3. The battery cell according to claim 2, characterized in that, The connecting piece (220) is bent in the middle, and the plane where the first end (221) is located is parallel to the plane where the second end (222) is located.

4. The battery cell according to claim 1, characterized in that, The tab (211) and the connecting piece (220) are connected by laser welding.

5. The battery cell according to claim 1, characterized in that, Several stacked cores (210) are arranged in pairs. After a pair of stacked cores (210) are connected to the connecting piece (220), they are folded in half. After a pair of stacked cores (210) are folded in half, their projections on one side of the stacked core (210) coincide.

6. The battery cell according to claim 1, characterized in that, The connecting piece (220) is an aluminum sheet.

7. The battery cell according to claim 1, characterized in that, The battery cell (200) is wrapped with an insulating coating (400), which fills the space between the battery cell (200) and the housing (300).

8. A lithium battery comprising the cell (200) according to any one of claims 1-7, characterized in that, It also includes a cover plate (100) and a housing (300), the battery cell (200) is disposed inside the housing (300), the cover plate (100) covers the housing (300) and together with the housing (300) forms a receiving cavity suitable for accommodating the battery cell (200).

9. The lithium battery according to claim 8, characterized in that, The cover plate (100) is provided with a terminal (110), which is used to connect the connecting piece (220). The terminal (110) and the connecting piece (220) are connected by laser soldering.

10. The lithium battery according to claim 8, characterized in that, The cover plate (100) and the housing (300) are connected by welding and sealing.

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