Cylindrical battery module

Abstract

The invention relates to the technical field of energy storage and power batteries, in particular to a cylindrical battery module which comprises a top plastic uptake support, a bottom plastic uptake support and a module-free battery pack. A module-free battery pack is installed in a fixing structure formed by combining plastic uptake supports, the top support is provided with receding holes to expose battery cell poles, the bottom support is provided with exhaust channels corresponding to anti-explosion valves, box bottom plate exhaust holes are communicated with bottom supporting cross beam exhaust channels to form a thermal runaway directional exhaust path, and a U-shaped liquid cooling plate is matched to reinforce thermal management. The modules, the positive electrode and the negative electrode adopt a copper-aluminum bar welding and riveting combined process, the plastic uptake bracket is fixed through a buckle or glue, and the cost is reduced by adopting a plastic uptake process; the invention has the beneficial effects that the plastic uptake process reduces the cost of the CCS bracket, the modular design improves the space ratio of the battery cell, so that the energy density and the directional exhaust system reduce the thermal runaway linkage risk, and the bracket size can be customized to adapt to the requirements of multiple scenes.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage and power batteries, and particularly relates to a cylindrical battery module. Background Art

[0002] In new energy vehicles and energy storage systems, cylindrical batteries are widely used due to their advantages such as stable structure and mature manufacturing process. The design of their battery packs must take into account core requirements such as cost control, energy density improvement, and safety optimization. The existing cylindrical battery pack structure usually adopts a module-level design, that is, the battery cells are integrated through the module frame and then assembled into a battery pack. Inside the module, the electrical connection and collection system (CCS) brackets of the battery cells are generally formed using the injection molding process. Although the injection molding process can achieve high-precision processing of complex structures, its mold development cost is high, the production cycle is long, and the material utilization rate is low. As a result, the manufacturing cost of the CCS bracket accounts for 20%-30% of the total module cost. The cost disadvantage is particularly significant when producing small batches of multiple specifications. In terms of energy density, traditional designs, due to the retention of module levels, require a large number of non-energy-carrying components such as module frames and fasteners, resulting in insufficient space for battery cells within the battery pack. For example, in the module structure of a cylindrical battery pack, the module frame and connecting components account for more than 15% of the weight, making it difficult for the battery pack to achieve an overall energy density exceeding 200Wh / kg, which cannot meet the requirements of new energy vehicles for long driving range and compact energy storage system layout. In terms of safety design, existing solutions for exhaust venting in the event of thermal runaway of battery cells have obvious flaws. The explosion-proof valve of a cylindrical battery cell is usually located at the bottom or top. When a battery cell experiences thermal runaway, if the high-temperature and high-pressure gas cannot be discharged in a timely and targeted manner, it is easy to accumulate in the battery pack and cause a chain reaction of failures in adjacent battery cells. In traditional designs, the battery box does not have a dedicated exhaust channel designed for the location of the battery cell explosion-proof valve. The gas discharge path is chaotic, and there is a lack of an effective thermal runaway isolation structure. This leads to a high risk of the spread of single-cell runaway, making it difficult to pass the thermal runaway protection tests in industry safety standards (such as GB38031-2021 "Safety Requirements for Power Batteries for Electric Vehicles"). In view of this, the present invention is proposed. Summary of the Invention

[0003] In order to solve the above technical problems existing in the prior art, the present invention provides a cylindrical battery module, which can solve the problems of high manufacturing cost, low energy density and lack of effective thermal runaway exhaust of battery module brackets in the prior art.

[0004] To achieve the above object, the technical solution of the present invention is as follows: A cylindrical battery module, comprising: a top blister bracket, a bottom blister bracket, and a module-free battery pack, wherein the module-free battery pack is mounted in a cell-fixing blister bracket formed by combining the top blister bracket and the bottom blister bracket; the top blister bracket and the bottom blister bracket cooperate with each other in a vertical manner to form a position-limiting and restraining structure for the module-free battery pack; The top blister bracket is provided with an avoidance hole for exposing the positive or negative electrode of the battery cell, and the bottom blister bracket is provided with an exhaust channel corresponding to the battery cell explosion-proof valve; The module-free battery pack includes multiple cylindrical battery cells, which are directly fixed by a top blister bracket and a bottom blister bracket to form a module-free battery pack structure; the size of the module-free battery pack and the number of the cylindrical battery cells are set according to actual needs.

[0005] Furthermore, the top blister bracket is a box structure, and the bottom surface of the top blister bracket is provided with a limiting groove that matches the top of the module-free battery pack.

[0006] Furthermore, the bottom blister bracket is provided with a limiting groove matching the module-free battery pack; The edge of the limiting groove is turned upward to form a three-dimensional positioning structure, and the explosion-proof valve at the bottom of the module-free battery pack faces the bottom blister bracket and is embedded in the limiting groove.

[0007] Furthermore, the limiting groove is in any one of a circular, square, elliptical and hexagonal shape.

[0008] Furthermore, it also includes a matching box, and the module-free battery pack is fixed in the box; The bottom plate of the box is provided with an exhaust hole corresponding to the exhaust channel of the bottom blister bracket; the exhaust hole is connected to the exhaust channel opened on the side of the supporting beam at the bottom of the box, and the exhaust channel extends to the explosion-proof valve of the box, forming a directional exhaust path when the battery cell has thermal runaway.

[0009] Furthermore, the shape of the exhaust holes on the bottom plate of the box body is any one of circular, square, elliptical or hexagonal, and the shape of the exhaust holes on the side of the bottom supporting beam is adapted to the shape of the exhaust holes on the bottom plate.

[0010] Furthermore, it also includes a liquid cooling plate, which is a U-shaped liquid cooling plate and is arranged below the bottom blister bracket and adheres to the surface of the module-free battery pack.

[0011] Furthermore, the modules and output positive and negative electrodes of the module-free battery pack adopt a copper-aluminum busbar series structure, and the copper-aluminum busbar is connected by a combined welding and riveting process.

[0012] Furthermore, the top blister bracket and the bottom blister bracket are both formed by blister technology, and the material is insulating and high-temperature resistant plastic.

[0013] Furthermore, the top blister bracket and the bottom blister bracket are fixedly connected by edge snaps or gluing.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The above-mentioned cylindrical battery module provided by the present invention is a top blister bracket and a bottom blister bracket prepared by the blister forming process, which reduces the manufacturing cost and cycle; the non-modular limiting structure simplifies non-energy components, improves the space share of the battery cell and the energy density of the battery pack; the battery cell explosion-proof valve directional exhaust system accurately vents thermal runaway gas and reduces the risk of chain failure; the U-shaped liquid cooling plate is equipped with a thermal conductive silicone sheet to enhance thermal management efficiency and temperature uniformity; the top bracket electrical isolation block and the wiring harness isolation column ensure the insulation of the electrical connection and signal stability; the size of the blister bracket can be flexibly adjusted with the arrangement of the battery cells and can adapt to a variety of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of a cylindrical battery module provided in an embodiment of the present invention; Figure 2 An exploded view of a cylindrical battery module provided by an embodiment of the present invention; Figure 3 A schematic diagram of the top blister of a cylindrical battery module provided by an embodiment of the present invention; Figure 4 A schematic structural diagram of the top blister bracket of a cylindrical battery module provided by an embodiment of the present invention; Figure 5 A CCS assembly diagram of a cylindrical battery module provided in an embodiment of the present invention; Figure 6 A detailed diagram of the CCS of a cylindrical battery module provided in an embodiment of the present invention; Figure 7 A schematic diagram of the structure of the series-connected aluminum bars of the cylindrical battery module provided by an embodiment of the present invention; Figure 8 A schematic diagram of the box structure of a cylindrical battery module provided in an embodiment of the present invention; Figure 9 A schematic cross-sectional view of a cylindrical battery module box provided in an embodiment of the present invention; Figure 10 An exploded view of a cylindrical battery module provided by an embodiment of the present invention; Figure 11 A schematic diagram of the module insertion positioning columns of the cylindrical battery module provided in an embodiment of the present invention; Figure 12Schematic diagram of the positioning diagram of the cylindrical battery module into the box provided by an embodiment of the present invention.

[0016] Description of reference numerals: 1. CCS assembly; 2. Top blister bracket; 3. Liquid cooling plate; 4. Module-free battery pack; 5. Bottom blister bracket; 6. Avoidance hole for the positive electrode of the battery cell; 7. Avoidance hole for the negative electrode of the battery cell; 8. Avoidance hole; 9. Wire harness isolation column; 10. Electrical isolation block; 11. Pressure riveted stud; 12. Rivet; 13. Copper busbar; 14. Aluminum busbar; 15. Battery cell explosion-proof hole; 16. Box bottom plate; 17. Exhaust hole; 18. Box cover; 19. Sealing ring; 20. CTP module; 21. Liquid cooling system; 22. Box; 23. Positioning column; 24. Positioning hole. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] It should be noted that, unless otherwise specifically stated, the relative arrangements of components and steps, and numerical expressions set forth in these embodiments should not be construed as limiting the scope of the present invention.

[0019] The following description of exemplary embodiments is merely illustrative and is not intended to limit the present invention, its application, or use in any sense. Technologies, methods, and apparatus known to those skilled in the art may not be discussed in detail herein, but to the extent applicable, such technologies, methods, and apparatuses should be considered part of this specification.

[0020] See Figure 1 and Figure 2 , which is a structural schematic diagram of a cylindrical battery module proposed in the present invention, including: a CCS assembly 1, a top blister bracket 2, a liquid plate 3, a module-free battery pack 4 and a bottom blister bracket 5. The module-free battery pack 4 is installed in a cell-fixing blister bracket formed by combining the top blister bracket 2 and the bottom blister bracket 5. The top blister bracket 2 and the bottom blister bracket 5 are matched up and down by edge snaps or gluing to form a limiting constraint structure for the module-free battery pack 4.

[0021] Specifically, the top blister bracket 2 is a box-shaped structure with a bottom surface provided with a retaining groove that matches the top of the module-free battery pack 4. The edge of the groove is turned upward to form a three-dimensional positioning structure. The bottom blister bracket 5 is provided with a retaining groove that matches the bottom of the module-free battery pack 4. The groove shape includes circular, square, oval, or hexagonal. The bottom explosion-proof valve of the module-free battery pack 4 faces the bottom blister bracket 5 and is embedded in the retaining groove to achieve radial positioning and fixation of the battery cell. Both the top blister bracket 2 and the bottom blister bracket 5 are formed using a blister process. The material is insulating and high-temperature resistant plastic, which reduces costs compared to traditional injection molding.

[0022] The liquid cooling plate 3 is a U-shaped structure, which is arranged below the bottom blister bracket 5 and adheres to the surface of the module-free battery pack 4. The water inlet and outlet are designed on the same side or both sides to achieve single-sided cooling of the battery cell. See Figure 3 and Figure 4 The top surface of the top blister support 2 is provided with a positive electrode avoidance hole 6 and a negative electrode avoidance hole 7 (or only one of the avoidance holes 8). The avoidance holes can be square, circular, or oval in shape, exposing the positive or negative electrode avoidance space of the battery cell for series welding. The electrical connection position of the top blister support 2 is provided with an aluminum busbar electrical connection hole (the hole shape can be square, circular, oval, or hexagonal), ensuring a welding path between the aluminum busbar 14 and the battery cell column.

[0023] See Figure 5 and Figure 6 The CCS assembly 1 is integrated into a cell-fixing blister bracket. This bracket features raised electrical isolation blocks 10 to ensure electrical clearance and creepage distances between adjacent aluminum bars 14. The top bracket utilizes a blister-forming process, with raised ribs or bosses for electrical isolation. The integrated wiring harness or FPC harness is affixed to the CCS bracket. Wire harness isolation posts 9 limit left-right movement of the harness, which is secured to the blister bracket with adhesive from the bottom. The series connection between modules and the output positive and negative poles utilizes copper bars 13 and aluminum bars 14 welded and riveted together to improve electrical connection reliability.

[0024] See Figure 7 In the composite copper-aluminum busbar assembly, the copper busbar 13 and the aluminum busbar 14 are welded and riveted by rivets 12 to form a copper-aluminum composite. The pressure riveting stud 11 is the connection structure for subsequent electrical connections. See Figures 9 to 12 The overall structure of the module-free battery pack 4 installed in the box 22 is as follows: The box body 22 is made using a sheet metal bending and welding process, and the bottom plate 16 is connected to the side beams by welding or riveting to ensure structural strength. The bottom plate 16 is provided with an exhaust hole 17 corresponding to the explosion-proof valve of the battery cell. The exhaust hole 17 is connected to the exhaust channel opened on the side of the supporting crossbeam at the bottom of the box body 22. The exhaust channel extends to the explosion-proof valve of the box body, forming a directional exhaust path in the event of thermal runaway. The bottom plate inside the box body 22 is provided with positioning columns 23 and positioning holes 24 for precise positioning of the module-free battery pack after it is placed in the box; the entire module is bonded and fixed to the bottom and side beams of the box body 22 by foam glue to ensure structural strength.

[0025] See Figure 10 The overall structure of the cylindrical battery module, from top to bottom, consists of a cover 18, a sealing ring 19, a CTP module 20, a liquid cooling system 21, and a housing 22. The cover 18 is sealed to the housing 22 via the sealing ring 19. The CTP module 20 (i.e., the combination of the module-less battery pack 4 and the blister bracket) is secured within the housing 22 via positioning posts 23 and foam adhesive. The U-shaped liquid cooling plate 3 of the liquid cooling system 21 fits against the bottom of the CTP module 20, achieving an integrated design for cell temperature control and thermal runaway exhaust.

[0026] The size and number of cells of the module-free battery pack 4 can be customized according to the spatial layout requirements of the actual application scenario, and the length and width dimensions of the top blister bracket 2 and the bottom blister bracket 5 can be customized to achieve modular expansion and adaptation.

[0027] In summary, the present invention has the following advantages: 1. Use the blister process on the battery holder to reduce costs and improve production efficiency; 2. Through the modular structural design of the battery, the proportion of non-energy components is reduced and the space utilization is improved; 3. The explosion-proof valve at the bottom of the battery cell corresponds to the exhaust hole at the bottom of the box, so that the gas can be quickly discharged to the outside of the body to prevent the high-temperature gas from spreading to adjacent battery cells.

[0028] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the scope of the technical solutions of the present invention, and all of these should be included in the scope of the claims of the present invention.

Claims

1. A cylindrical battery module, characterized in that: include: A top blister bracket, a bottom blister bracket and a module-free battery pack, wherein the module-free battery pack is installed in a cell-fixing blister bracket formed by combining the top blister bracket and the bottom blister bracket; The top blister bracket and the bottom blister bracket cooperate with each other up and down to form a limiting constraint structure for the module-free battery pack; The top blister bracket is provided with an avoidance hole for exposing the positive or negative pole of the battery cell, and the bottom blister bracket is provided with an exhaust channel; the module-free battery pack includes multiple cylindrical battery cells, and the multiple cylindrical battery cells are directly fixed by the top blister bracket and the bottom blister bracket to form a module-free battery pack structure; the size of the module-free battery pack and the number of the cylindrical battery cells are set according to actual needs.

2. The cylindrical battery module according to claim 1, characterized in that: The top blister bracket is a box structure, and the bottom surface of the top blister bracket is provided with a limiting groove that matches the top of the module-free battery pack.

3. The cylindrical battery module according to claim 1, characterized in that: The bottom blister bracket is provided with a limiting groove matching the module-free battery pack; The edge of the limiting groove is turned upward to form a three-dimensional positioning structure, and the explosion-proof valve at the bottom of the module-free battery pack faces the bottom blister bracket and is embedded in the limiting groove.

4. The cylindrical battery module according to claim 3, characterized in that: The limiting groove has a shape of any one of circular, square, elliptical and hexagonal.

5. The cylindrical battery module according to claim 1, characterized in that: It also includes a matching box, in which the module-free battery pack is fixed; The bottom plate of the box is provided with an exhaust hole corresponding to the exhaust channel of the bottom blister bracket; the exhaust hole is connected to the exhaust channel opened on the side of the supporting beam at the bottom of the box, and the exhaust channel extends to the explosion-proof valve of the box, forming a directional exhaust path when the battery cell has thermal runaway.

6. The cylindrical battery module according to claim 5, characterized in that: The shape of the exhaust holes on the bottom plate of the box body is any one of circular, square, elliptical or hexagonal, and the shape of the exhaust holes on the side of the bottom supporting beam is adapted to the shape of the exhaust holes on the bottom plate.

7. The cylindrical battery module according to claim 1, characterized in that: It also includes a liquid cooling plate, which is a U-shaped liquid cooling plate and is arranged below the bottom blister bracket and adheres to the surface of the module-free battery pack.

8. The cylindrical battery module according to claim 1, characterized in that: The modules and output positive and negative electrodes of the module-free battery pack adopt a copper-aluminum busbar series structure, and the copper-aluminum busbar is connected by a combined welding and riveting process.

9. The cylindrical battery module according to claim 1, characterized in that: The top blister bracket and the bottom blister bracket are both formed by blister technology, and the material is insulating and high-temperature resistant plastic.

10. The cylindrical battery module according to claim 1, characterized in that: The top blister bracket and the bottom blister bracket are fixedly connected by edge buckles or gluing.

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