Convergence welding bar structure for high-current stainless steel shell battery cell PACK

Abstract

The confluence welding row structure for the high-current stainless steel shell battery cell PACK comprises an upper cover plate, a lower cover plate, a battery cell bag arranged between the upper cover plate and the lower cover plate, a welding layer arranged on the upper cover plate, and a confluence layer arranged on the welding layer, the welding layer is connected with the battery cell package, the convergence layer covers the welding layer, the convergence layer is provided with a terminal, and the battery cell package is connected with an external circuit through the terminal; the upper cover plate is provided with a positioning pin, the welding layer is provided with a welding positioning hole corresponding to the positioning pin, the confluence layer is provided with a confluence positioning hole corresponding to the positioning pin, and the welding positioning hole and the confluence positioning hole sequentially penetrate through the positioning pin, so that the welding layer and the confluence layer are mounted on the upper cover plate. According to the utility model, the convergence layer is covered on the welding layer, so that the problem of limitation of the existing battery pack in the aspects of current bearing capacity and heat dissipation is solved.

Description

Technical Field

[0001] This utility model belongs to the field of battery pack manufacturing, and in particular relates to a busbar structure for a high-current stainless steel shell battery cell PACK. Background Technology

[0002] A stainless steel-cased battery pack is an electrochemical energy storage device encapsulated in stainless steel. This type of battery pack typically consists of multiple individual battery cells connected in series or parallel to achieve the required voltage and capacity. Stainless steel is chosen for its excellent corrosion resistance, mechanical strength, and thermal stability, ensuring reliable battery operation in harsh environments. Stainless steel-cased battery packs are widely used in industrial, military, aerospace, and electric vehicle fields. Especially in the electric vehicle industry, where high-performance battery packs are an indispensable core component due to the high requirements for driving range, safety, and stability, stainless steel-cased battery packs offer even greater advantages in special environments, such as high-temperature, high-pressure, or highly corrosive conditions.

[0003] With advancements in technology and increasing application demands, various fields are placing higher requirements on the performance of stainless steel-cased battery packs. Especially for high-power applications such as heavy-duty electric vehicles and energy storage systems, not only are higher output voltages required, but the ability to handle larger operating currents is also essential. This is because high current enables fast charging and releases a significant amount of energy in a short time, which is crucial for improving equipment efficiency.

[0004] Currently, most stainless steel-cased battery packs rely on resistance welding for cell welding. However, due to limited internal space and manufacturing constraints, the nickel strips used for welding cannot be too large or thick, directly limiting the maximum current that the busbars can carry. Traditional nickel strip welding layers cannot effectively handle high current density applications. When the current density exceeds a certain limit, it may cause localized overheating, affecting the stability and lifespan of the weld joint, and even potentially leading to safety risks. Furthermore, in existing stainless steel-cased battery pack designs, the contact area between the weld joint and the busbar is small, hindering heat dissipation. Under prolonged operation, high temperatures accelerate material aging, further reducing current carrying capacity and potentially causing performance degradation or malfunctions. Utility Model Content

[0005] The purpose of this utility model is to provide a busbar structure for high-current stainless steel shell battery cell PACK, so as to solve the technical problem of insufficient current carrying capacity.

[0006] To achieve the above objectives, the specific technical solution of this utility model for a busbar structure for a high-current stainless steel shell battery cell PACK is as follows:

[0007] A busbar structure for a high-current stainless steel shell battery cell PACK includes an upper cover plate and a lower cover plate, a battery cell pack disposed between the upper cover plate and the lower cover plate, a welding layer disposed on the upper cover plate, and a busbar layer disposed on the welding layer.

[0008] The welding layer is connected to the battery pack, the bus layer covers the welding layer, and the bus layer is provided with terminals to connect the battery pack to an external circuit.

[0009] The upper cover plate is provided with a positioning pin, the welding layer is provided with a welding positioning hole corresponding to the positioning pin, and the busbar layer is provided with a busbar positioning hole corresponding to the positioning pin. The welding positioning hole and the busbar positioning hole pass through the positioning pin in sequence to realize the installation of the welding layer and the busbar layer on the upper cover plate.

[0010] As a further improvement of this utility model, the battery cell assembly includes a plurality of battery cells, the welding layer includes welding nickel sheets corresponding to the battery cell assembly, and the bus layer includes bus copper sheets corresponding to the welding nickel sheets.

[0011] As a further improvement of this utility model, the side of the upper cover plate facing the welding layer forms a mounting groove corresponding to the recess of the battery cell assembly, and the welding nickel sheet enters the mounting groove and connects to the battery cell assembly.

[0012] As a further improvement of this utility model, the busbar copper sheet is ultrasonically connected to cover the welded nickel sheet.

[0013] As a further improvement of this utility model, the terminal is connected to the battery management system via a data acquisition line to feed back the real-time parameters of the battery cell to the battery management system.

[0014] As a further improvement of this utility model, the positioning pin protrudes into the welding layer within the mounting groove.

[0015] As a further improvement of this utility model, one side of the busbar copper sheet is bent to form a terminal, and the terminal passes through the mounting groove and protrudes on the side of the upper cover plate for connection to external circuits.

[0016] As a further improvement of this utility model, a welding hole is provided in the mounting groove, and the welding hole is correspondingly provided with the battery cell to realize the connection between the welding nickel sheet and the battery cell assembly.

[0017] As a further improvement of this utility model, the welding layer is made of nickel, and the busbar layer is made of copper.

[0018] Beneficial effects:

[0019] The locating pins on the top cover plate engage with corresponding holes on the welding layer and the busbar layer, ensuring precise alignment of the welding layer and the busbar layer during installation. This precise positioning mechanism not only simplifies the assembly process but also improves the consistency and stability of the welding points, reducing the risk of poor contact or short circuits caused by positional deviations.

[0020] Using copper, a material with excellent electrical conductivity, as the bus layer effectively reduces contact resistance and increases current carrying capacity. This is especially important for applications requiring high power output, enabling the transmission of larger currents without overheating.

[0021] The design of the bus layer covering the solder layer ensures more uniform and stable current transmission from the battery cell to the external circuit, reducing the possibility of local current concentration, thereby improving the efficiency and safety of the entire system.

[0022] Using ultrasonic welding to join the copper and nickel sheets provides a more stable and reliable weld quality than traditional resistance welding. Ultrasonic welding can achieve a high-strength metallurgical bond without the use of additional solder, while avoiding damage that may be caused by an excessively large heat-affected zone.

[0023] The mounting groove formed on the side of the top cover facing the welding layer not only provides a safe space for welding nickel sheets, allowing them to better fit the cell assembly, but also helps dissipate heat and maintain the optimal operating temperature of the cells. The busbar layer is not only part of the electrical connection, but also plays a role in strengthening the structure and enhancing the overall mechanical strength of the battery pack, especially under vibration or shock environments.

[0024] The terminal connects to the battery management system (BMS) via a data acquisition line, allowing real-time parameters of the battery cells (such as voltage and temperature) to be fed back to the BMS for timely monitoring and management of the battery status, ensuring that it always operates under optimal conditions.

[0025] In summary, the high-current stainless steel shell battery cell PACK busbar structure proposed in this utility model, through optimized design and material selection, not only improves the current carrying capacity and electrical connection reliability of the battery pack, but also enhances thermal management and mechanical strength, simplifies maintenance operations, and integrates advanced monitoring functions, providing strong support for the application of high-performance battery packs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a busbar structure for a high-current stainless steel shell battery cell PACK according to the present invention.

[0027] Figure 2 This is a schematic diagram of the upper cover plate structure;

[0028] The markings in the diagram are as follows: 1. Lower cover plate; 2. Battery cell pack; 3. Upper cover plate; 31. Mounting groove; 32. Positioning pin; 33. Welding hole; 4. Welding layer; 41. Welding nickel sheet; 42. Welding positioning hole; 5. Busbar layer; 51. Busbar copper sheet; 52. Terminal; 53. Busbar positioning hole. Detailed Implementation

[0029] To enhance understanding of this utility model, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. These embodiments are only used to explain the present utility model and do not constitute a limitation on the scope of protection of the present utility model.

[0030] Implementation example:

[0031] like Figure 1-2 The diagram shows a busbar structure for a high-current stainless steel shell battery cell PACK. The upper cover plate 3 and the lower cover plate 1 wrap the battery cell pack to maintain the structural integrity of the entire battery cell pack 2. The welding layer 4 and the busbar layer 5 cover the upper cover plate 3 and connect to the battery cell pack 2 in sequence, directly connecting the positive and negative terminals of the individual battery cells together to form a stable electrical path. At the same time, the external circuit is connected through the terminal block to complete the construction of the entire battery pack electrical architecture.

[0032] The lower cover plate 1 and the upper cover plate 3 clamp the battery pack 2 on opposite sides through placement slots. The battery pack 2 is divided into several battery cell groups according to the area. The upper cover plate 3 has mounting slots 31 on its outer side corresponding to the battery cell groups. Welding holes 33 are provided through the mounting slots 31, corresponding to the battery cells, allowing the cells to pass through and connect with the welding layer 4. Positioning pins 32 are provided in the mounting slots 31, with two positioning pins 32 corresponding to each other in the same mounting slot 31, to achieve the installation and positioning of the welding layer 4 and the bus layer 5.

[0033] The welding layer 4 is made of nickel and consists of several welding nickel sheets 41. The welding nickel sheets 41 are matched with the size of the mounting groove 31. Welding positioning holes 42 are provided for the corresponding positioning pins 32. The positioning pins 32 are inserted through the welding positioning holes 42, and the welding nickel sheets 41 are embedded into the mounting groove 31 and connected to the battery cell through the welding holes 33.

[0034] The busbar layer 5 is made of copper, and the corresponding nickel sheet 41 is composed of a busbar copper sheet 51. A positioning pin 32 protrudes from the welding positioning hole 42 within the mounting groove 31 and is inserted through the busbar positioning hole 53. The busbar copper sheet 51 covers the nickel sheet 41, and a bent terminal 52 on one side passes through the mounting groove 31 and protrudes from the side of the upper cover plate 3. The exposed terminal 52 can be easily connected to an external circuit. In this embodiment, the terminal 52 serves as a data acquisition point, connected to the battery management system via a data acquisition line. Key parameters such as voltage and temperature of each battery cell are transmitted to the battery management system. In this way, the battery management system can monitor the battery status in real time and implement necessary protection measures, such as overcharge, over-discharge, and short-circuit protection, thereby ensuring the safe operation of the battery.

[0035] The copper busbar 51 is ultrasonically bonded to cover the nickel busbar 41. The frictional heat generated by high-frequency vibration causes the two materials to form a metallurgical bond in the solid state, achieving a stable and efficient electrical connection. This method provides high-quality, reliable weld points with excellent electrical and mechanical properties. Ultrasonic welding creates a very tight metal-to-metal contact, significantly reducing contact resistance. Both copper and nickel are metals with good thermal conductivity. Ultrasonic welding ensures a tight contact between them, forming an efficient heat conduction path. This helps to rapidly conduct heat generated at and around the weld point to the busbar layer and other heat dissipation components, preventing localized overheating. It also reduces energy loss during current flow, thus lowering heat generation. Lower heat generation means the battery cell and weld point can maintain a more stable operating temperature range, which is beneficial for improving current carrying capacity.

[0036] This invention utilizes the upper cover plate 3 and lower cover plate 1 to form a robust outer shell, enhancing the mechanical strength of the entire cell pack 2 and ensuring its ability to withstand vibration and impact during transportation, installation, and use. The positioning pins 32 and corresponding welding positioning holes 42 and busbar positioning holes 53 on the upper cover plate 3 ensure proper alignment between layers, improving assembly efficiency and quality. Ultrasonic welding is used to connect the busbar copper sheet and the welding nickel sheet, forming a high-strength metallurgical bond, reducing contact resistance and energy loss, thereby significantly improving current carrying capacity. The use of highly conductive copper as the busbar layer material ensures efficient and stable high-current transmission. The terminals are connected to the battery management system (BMS) via acquisition lines, allowing real-time parameters of the cell (such as voltage and temperature) to be fed back to the BMS, ensuring optimal operation. This design not only overcomes the limitations of existing battery packs in terms of current carrying capacity and heat dissipation but also improves overall electrical connection reliability, mechanical strength, and maintenance convenience. These improvements lay a solid foundation for building high-performance, safe, and reliable high-current stainless steel-cased cell packs, meeting the higher requirements of modern applications.

[0037] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A busbar structure for a high-current stainless steel shell battery cell PACK, characterized in that, It includes an upper cover plate and a lower cover plate, a cell pack disposed between the upper cover plate and the lower cover plate, a welding layer disposed on the upper cover plate, and a bus layer disposed on the welding layer; The welding layer is connected to the battery pack, the bus layer covers the welding layer, and the bus layer is provided with terminals to connect the battery pack to an external circuit. The upper cover plate is provided with a positioning pin, the welding layer is provided with a welding positioning hole corresponding to the positioning pin, and the busbar layer is provided with a busbar positioning hole corresponding to the positioning pin. The welding positioning hole and the busbar positioning hole pass through the positioning pin in sequence to realize the installation of the welding layer and the busbar layer on the upper cover plate.

2. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 1, characterized in that, The battery pack includes several battery cell groups, each battery cell group includes several battery cells, the welding layer includes welding nickel sheets corresponding to the battery cell groups, and the bus layer includes bus copper sheets corresponding to the welding nickel sheets.

3. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 2, characterized in that, The side of the upper cover plate facing the welding layer forms a mounting groove corresponding to the recess of the battery cell assembly, and the welding nickel sheet enters the mounting groove to connect with the battery cell assembly.

4. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 2, characterized in that, The busbar copper sheet is ultrasonically connected to cover the welded nickel sheet.

5. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 1, characterized in that, The terminal is connected to the battery management system via a data acquisition line, and the real-time parameters of the battery cell are fed back to the battery management system.

6. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 3, characterized in that, The locating pin protrudes into the weld layer within the mounting groove.

7. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 3, characterized in that, The copper busbar is bent on one side to form a terminal, which passes through the mounting groove and protrudes from the side of the upper cover plate for connection to external circuits.

8. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 3, characterized in that, The mounting groove is provided with welding holes, which are corresponding to the battery cells to realize the connection between the welding nickel sheet and the battery cell assembly.

9. The busbar structure for high-current stainless steel shell battery cell PACK according to claim 1, characterized in that, The welding layer is made of nickel, and the busbar layer is made of copper.

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