Soft pack battery unit and vehicle having the same

Abstract

The present invention provides a soft-pack battery cell and a vehicle having the same, and relates to the field of battery technology. The soft-pack battery cell includes: a soft-pack battery roll core, the soft-pack battery roll core has a positive pole ear and a negative pole ear; a roll core skeleton, the roll core skeleton includes a hollow insulating skeleton and a hollow conductor skeleton, there are two hollow conductor skeletons, one of which is connected to the first end of the hollow insulating skeleton, and the other is connected to the second end of the hollow insulating skeleton; the soft-pack battery roll core is wound on the roll core skeleton. Applying the technical solution of the present invention, by winding the soft-pack battery roll core on the roll core skeleton, the roll core skeleton can be used to effectively support the soft-pack battery cell, avoiding the collapse of the center hole of the cylindrical battery cell, solving the technical problem of the innermost circle pole piece of the battery cell winding structure lacking support and collapsing in the prior art, and improving the structural strength of the soft-pack battery cell.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a soft-pack battery unit and a vehicle having the same. Background Art

[0002] Lithium-ion batteries have poor stability, and if internal process defects occur, they will cause safety problems such as thermal runaway.

[0003] Compared with other structures such as laminated sheets, square and cylindrical wound cell structures have the advantage of high production efficiency and are widely used. However, the wound structure in the prior art has structural problems such as the collapse of the innermost circle electrode of the cell due to lack of support, and the excessive gap between the inner circle cathode and anode electrodes. For example, the central hole of the cylindrical cell collapses, and the innermost circle corner of the square shell cell has large electrode gaps, which lead to insufficient local dynamics of the battery and lithium deposition, causing safety problems such as thermal runaway of the battery.

[0004] With regard to the technical problem that the innermost pole piece of the above-mentioned battery cell winding structure collapses due to lack of support, no effective solution has been proposed so far. Summary of the invention

[0005] The main purpose of the present invention is to provide a soft-pack battery unit and a vehicle having the same, so as to solve the technical problem in the prior art that the innermost pole piece of the battery cell winding structure lacks support and collapses.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a soft-pack battery unit is provided, comprising: a soft-pack battery core, the soft-pack battery core having a positive electrode tab and a negative electrode tab; a core skeleton, the core skeleton comprising a hollow insulating skeleton and a hollow conductor skeleton, there are two hollow conductor skeletons, one of which is connected to the first end of the hollow insulating skeleton, and the other is connected to the second end of the hollow insulating skeleton; the soft-pack battery core is wound on the core skeleton, the positive electrode tab is connected to one of the hollow conductor skeletons, and the negative electrode tab is connected to the other hollow conductor skeleton.

[0007] Furthermore, the winding core skeleton also includes: a sampling component, the sampling component is connected to at least one of the hollow insulating skeleton and the hollow conductor skeleton, and the sampling component is used to collect at least one of the temperature and voltage of the soft-pack battery cell.

[0008] Furthermore, a groove structure is provided on the outer surface of the roll core skeleton, and the sampling component covers the groove structure.

[0009] Furthermore, the sampling component includes: a composite cover plate, which covers the groove structure and is connected to at least one of the hollow insulating skeleton and the hollow conductor skeleton; a sampling unit, which is arranged on a side of the composite cover plate close to the groove structure, and at least part of the sampling unit extends into the groove structure, and the sampling unit is used to collect at least one of the temperature and voltage of the soft-pack battery cell.

[0010] Furthermore, at least one of the groove structure and the composite cover plate is provided with a ventilation hole.

[0011] Furthermore, the groove structure includes a first groove opened on the outer surface of the hollow conductor skeleton, and a second groove opened on the outer surface of the hollow insulating skeleton, wherein the first groove is arranged to communicate with the second groove, and a ventilation hole is opened on the second groove.

[0012] Furthermore, the ventilation holes are covered with a waterproof and breathable membrane.

[0013] Furthermore, the sampling unit includes a sampling main body harness, and a temperature sampling nickel sheet and a voltage sampling nickel sheet connected to the sampling main body harness. The temperature sampling nickel sheet is arranged corresponding to the hollow insulating skeleton, and the voltage sampling nickel sheet is arranged corresponding to the hollow conductor skeleton.

[0014] Furthermore, the sampling main harness is a sampling harness plate, on which a temperature sampling nickel sheet and a voltage sampling nickel sheet are arranged, and the sampling harness plate is connected to a side of the composite cover plate close to the groove structure.

[0015] Furthermore, structural adhesive is filled between the composite cover plate and the roll core frame.

[0016] Furthermore, the outer surface of the soft-pack battery core is wrapped with an aluminum-plastic film, and the aluminum-plastic film and the soft-pack battery core are sealed and connected through a thermal composite process.

[0017] Furthermore, at least one of the hollow insulating skeleton and the hollow conductor skeleton is used for passing cooling liquid.

[0018] According to another aspect of the present invention, a vehicle is provided. The vehicle includes a soft-pack battery cell, and the soft-pack battery cell is the soft-pack battery cell described above.

[0019] By applying the technical solution of the present invention, by winding the soft-pack battery core on the core skeleton, the core skeleton can be used to effectively support the soft-pack battery unit, thereby preventing the center hole of the cylindrical battery cell from collapsing, solving the technical problem of the innermost circle electrode sheet of the battery cell winding structure lacking support and collapsing in the prior art, and improving the structural strength of the soft-pack battery unit. At the same time, the problem of large gap between the electrode sheets at the innermost corner of the square shell battery cell is solved, thereby avoiding the problem of insufficient lithium precipitation due to local dynamics of the battery unit and improving the safety performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 A schematic structural diagram of a first embodiment of a soft-pack battery pack according to the present invention is shown;

[0022] Figure 2 Shown according to Figure 1 A local enlarged view of P1;

[0023] Figure 3 Shown according to Figure 1 A local enlarged view of P2;

[0024] Figure 4 Shown according to Figure 1 An enlarged schematic diagram of the P3 portion;

[0025] Figure 5 An exploded view of the structure of a soft-pack battery cell according to the present invention is shown;

[0026] Figure 6 A schematic structural diagram of a first embodiment of a soft-pack battery cell according to the present invention is shown;

[0027] Figure 7 A schematic structural diagram of a second embodiment of a soft-pack battery cell according to the present invention is shown.

[0028] The above drawings include the following reference numerals:

[0029] 1. hollow conductor skeleton; 11. first metal segment; 12. second metal segment; 100. first groove;

[0030] 2. Hollow insulating skeleton; 21. First insulating section; 211. First ventilation hole; 212. First waterproof breathable membrane; 22. Second insulating section; 200. Second groove;

[0031] 3. Hollow I-shaped conductor shaft; 4. Hollow insulating connector; 5. Hollow conductive connector;

[0032] 6. Sampling components;

[0033] 61, composite cover plate; 611, first plate body; 612, second plate body; 613, third plate body; 6131, second waterproof breathable membrane; 6132, second breathable through hole;

[0034] 62. Sampling unit; 621. Sampling main wiring harness; 622. Temperature sampling nickel sheet; 623. Voltage sampling nickel sheet;

[0035] A. Snake-shaped hollow sampling long axis; B. Core assembly; D. Battery pack lower box; E. Hollow long axis. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of the layers and regions may be enlarged, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

[0040] To facilitate the description of the technical effects of the technical solution of the present application, the battery structure and manufacturing process in the prior art are introduced as follows:

[0041] As for lithium-ion batteries, the following problems exist in lithium-ion batteries at present: ① Lithium-ion batteries have poor stability. If internal process defects occur, thermal runaway and other safety issues will occur. ② With the development of the new energy industry, high energy density battery packs are constantly pursued. ③ High structural strength cells can enable the cells to withstand higher structural strength and improve the mechanical safety performance of the cells. ④ Production efficiency has a great impact on cost, and efficient production methods can increase cost reduction space. ⑤ The ideal operating temperature of the battery is around 25°C, and temperatures that are too high or too low will affect its performance. The design of an efficient thermal management system is crucial to the battery system.

[0042] The existing battery structure design and manufacturing process are as follows: ① Compared with other structures such as lamination, the winding structure has the advantage of high production efficiency and is widely used. ② Compared with the hard shell structure, the soft package packaging structure is light in weight and has the advantage of high energy density, so it is used in applications with high energy density requirements. ③ In the existing pack structure, the battery cell is the protected component in the pack. ④ At the battery cell level, the existing winding is produced with a single core as a unit, and there are multiple subsequent processes such as battery cell assembly. At the battery pack level, multiple single cell assembly, battery cell series welding and other processes are required. ⑤ Thermal management system technology: Common heat dissipation methods include air cooling, liquid cooling, phase change materials and heat pipes. Among them, liquid cooling technology has been widely used in the heat dissipation design of battery systems due to its mature application and good cooling effect. In the existing technology, when liquid cooling technology is used to dissipate heat for battery systems, it is mainly divided into system-level heat dissipation, that is, a whole liquid cooling plate is arranged at the bottom of the battery system box; module-level heat dissipation, that is, the liquid cooling plate is arranged in the module shell (including the lower shell, side plate), etc. Since the traditional liquid cooling structure design is relatively simple, the entire liquid cooling plate is usually placed at the bottom of the battery system or on one side of the module, and it only dissipates heat on one side. ⑥ In the existing pack design, the cooling system and the sampling system are independent of each other and occupy two parts of space respectively.

[0043] Based on the above battery technology, there are the following technical problems:

[0044] ① The innermost pole piece of the existing wound structure battery cell lacks support and collapses, and the gap between the inner positive and negative pole pieces is too large. For example, the center hole of the cylindrical battery cell collapses, and the gap between the pole pieces at the innermost corner of the square shell battery cell is large, which leads to insufficient local dynamics and lithium precipitation, causing safety problems.

[0045] ② The soft-pack structure battery cell has low structural strength, and the module structure cannot be eliminated when grouping, which limits the further improvement of the pack energy density.

[0046] ③ In the existing technology, the battery cell has poor structural strength and mechanical safety. At the system level, the battery cell is used as a protective component, and a large number of structural components are used to protect the battery cell when grouping, sacrificing the system energy density.

[0047] ④ Production is carried out with a single cell as a unit, resulting in low production efficiency. A battery pack composed of single cells requires assembly between the single cells and the connection of many single cells in series, resulting in a complex production process and low production efficiency.

[0048] ⑤ Due to the simple structure of liquid cooling, its form is often only a single board with a single heat dissipation surface, which cannot meet the heat dissipation of the battery in multiple directions. It will also lead to problems such as small effective heat dissipation area of ​​the battery module, low heat dissipation efficiency, and large temperature differences at different positions. These problems will seriously affect the service life of the battery system and limit the fast charging and low-temperature use of the battery cells.

[0049] ⑥ In the existing pack design, the cooling system and the sampling system are independent of each other and occupy two parts of space respectively, sacrificing the pack energy density.

[0050] In response to the above technical problems, the present application provides an embodiment of a soft-pack battery cell, a soft-pack battery pack and a vehicle to solve the above technical problems.

[0051] Combination Figures 1 to 7 As shown, according to a specific embodiment of the present application, a soft-pack battery cell is provided.

[0052] Specifically, the soft-pack battery unit includes a soft-pack battery core and a core skeleton, the soft-pack battery core has a positive electrode tab and a negative electrode tab; the core skeleton includes a hollow insulating skeleton 2 and a hollow conductor skeleton 1, there are two hollow conductor skeletons 1, one of which is connected to the first end of the hollow insulating skeleton 2, and the other hollow conductor skeleton 1 is connected to the second end of the hollow insulating skeleton 2; the soft-pack battery core is wound on the core skeleton, the positive electrode tab is connected to one of the hollow conductor skeletons 1, and the negative electrode tab is connected to the other hollow conductor skeleton 1.

[0053] By applying the technical solution of this embodiment, by winding the soft-pack battery core on the core frame, the core frame can be used to effectively support the soft-pack battery unit, thereby preventing the center hole of the cylindrical battery cell from collapsing, solving the technical problem of the innermost circle electrode sheet of the battery cell winding structure lacking support and collapsing in the prior art, and improving the structural strength of the soft-pack battery unit. At the same time, the problem of large gap between the electrode sheets at the innermost corner of the square shell battery cell is solved, thereby avoiding the problem of insufficient local dynamics of the battery unit and lithium precipitation, thereby improving the safety performance of the battery cell.

[0054] Optionally, at least one of the hollow insulating skeleton 2 and the hollow conductor skeleton 1 is used to pass cooling liquid. By circulating cooling liquid into the hollow insulating skeleton 2 and the hollow conductor skeleton 1, the battery can be cooled on all four sides, thereby improving the thermal management efficiency.

[0055] In an exemplary embodiment of the present application, the cooling liquid is cooling water to which a carbon dioxide additive is added, so that while achieving a cooling effect, the carbon dioxide gas discharged from the battery cell is absorbed to solve the problem of soft pack bloating.

[0056] Specifically, the winding core skeleton also includes a sampling component 6, which is connected to at least one of the hollow insulating skeleton 2 and the hollow conductor skeleton 1, and is used to collect at least one of the temperature and voltage of the soft-pack battery cell. The setting of the sampling component 6 can collect the real temperature and voltage inside the battery cell, providing effective reference and support for the fast charging capability of the battery cell.

[0057] Furthermore, a groove structure is provided on the outer surface of the core skeleton, and the sampling component 6 covers the groove structure. By providing the groove structure on the outer surface of the core skeleton, the weight of the core skeleton can be reduced. At the same time, the groove structure can be provided to position the assembly of the sampling component 6, thereby improving the installation efficiency.

[0058] Specifically, the sampling assembly 6 includes a composite cover plate 61 and a sampling unit 62. The composite cover plate 61 covers the groove structure and is connected to at least one of the hollow insulating skeleton 2 and the hollow conductor skeleton 1. The sampling unit 62 is arranged on the side of the composite cover plate 61 close to the groove structure, and at least part of the sampling unit 62 extends into the groove structure. The sampling unit 62 is used to collect at least one of the temperature and voltage of the soft-pack battery cell. The sampling unit 62 is located in the groove structure, and the composite cover plate 61 covers the groove structure, which can protect the sampling unit 62 and ensure that the sampling unit 62 works stably for a long time.

[0059] Specifically, at least one of the groove structure and the composite cover plate 61 is provided with a ventilation hole. The ventilation hole can discharge the gas generated during the operation of the battery cell, solve the problem of bloating of the battery pack, and avoid safety accidents caused by excessive pressure difference inside and outside the battery pack.

[0060] The ventilation holes are covered with a waterproof and breathable film, which can prevent liquid from entering and exiting the ventilation holes, and avoid the problem of battery pack bloating caused by liquid blocking the ventilation holes and causing gas to not be discharged in time.

[0061] Furthermore, the groove structure includes a first groove 100 opened on the outer surface of the hollow conductor skeleton 1, and a second groove 200 opened on the outer surface of the hollow insulating skeleton 2, wherein the first groove 100 is arranged in communication with the second groove 200, and a ventilation hole is opened on the second groove 200. The first groove 100 and the second groove 200 are arranged in communication with each other to match the composite cover plate 61 and the sampling unit 62, which is convenient for the subsequent fixed connection process of the composite cover plate 61 and the hollow conductor skeleton 1 and the hollow insulating skeleton 2, and improves production efficiency. The second groove 200 is provided with a ventilation hole, which allows the exhaust gas of the battery cell to be discharged into the hollow structure through the ventilation hole, solving the problem of bloating of the soft-pack battery.

[0062] Specifically, the sampling unit 62 includes a sampling main body harness 621, and a temperature sampling nickel sheet 622 and a voltage sampling nickel sheet 623 connected to the sampling main body harness 621. The temperature sampling nickel sheet 622 is arranged corresponding to the hollow insulating skeleton 2, and the voltage sampling nickel sheet 623 is arranged corresponding to the hollow conductor skeleton 1. This arrangement is conducive to the connection of the voltage sampling nickel sheet 623 with the pole ear of the battery cell to collect the battery cell voltage. The temperature sampling nickel sheet 622 is located in the middle of the battery cell, and the temperature is measured more accurately, which improves the collection accuracy and provides support for the fast charging capability.

[0063] It should be understood that the number of temperature sampling nickel sheets 622 can be adjusted according to design requirements. For example, multiple temperature sampling nickel sheets 622 can be set and the positions of the multiple temperature sampling nickel sheets 622 can be reasonably distributed. The collected data of the multiple temperature sampling nickel sheets 622 can be analyzed and determined to determine the actual temperature of the battery cell.

[0064] Specifically, the sampling main harness 621 is a sampling harness board, on which a temperature sampling nickel sheet 622 and a voltage sampling nickel sheet 623 are provided, and the sampling harness board is connected to a side of the composite cover plate 61 close to the groove structure. The sampling harness board can cooperate with the groove structure to simplify the structural assembly and improve production efficiency. Optionally, the sampling main harness 621 is a flexible harness board.

[0065] Among them, structural glue is filled between the composite cover plate 61 and the core frame. The sampling component 6 and the core frame are fixed by the structural glue, so that the internal structure of the entire soft-pack battery is in a stable state, so that the soft-pack battery structure reaches a level equivalent to the hard shell CTP structure strength, greatly improving the structural strength of the soft-pack battery pack.

[0066] In one embodiment of the present application, the outer surface of the soft-pack battery core is wrapped with an aluminum-plastic film, and the aluminum-plastic film and the soft-pack battery core are sealed and connected by a thermal composite process. The aluminum-plastic film is used to seal and package the soft-pack battery core, which can provide good protection and improve the toughness and strength of the soft-pack battery core. The thermal composite process is easy to operate, quickly realizes the sealing process, and improves the production efficiency of the soft-pack battery.

[0067] In an exemplary embodiment of the present application, the hollow insulating skeleton 2 includes a first insulating section 21 and a second insulating section 22. The first insulating section 21 is made of metal material, the inner wall of the first insulating section 21 is coated with a heat-conductive and anti-corrosion coating, and the outer wall of the first insulating section 21 is coated with an insulating coating; the second insulating section 22 is made of an insulating and heat-conductive material, and there are two second insulating sections 22, one of which is arranged at the first end of the first insulating section 21, and the other second insulating section 22 is arranged at the second end of the first insulating section 21; wherein, a ventilating through hole is provided in the second groove 200 on the first insulating section 21. Such a material setting can effectively improve the thermal conductivity of the battery and the cooling water, and effectively prevent the cooling water from corroding the battery shell. The second groove 200 is provided with a ventilating through hole, which can discharge the gas generated during the operation of the battery cell, solve the problem of flatulence of the battery pack, and avoid safety accidents caused by excessive pressure difference inside and outside the battery pack.

[0068] The first insulating section 21 and the second insulating section 22 are fixedly connected, and the connection method may be mixed injection molding, gluing or mechanical fixing.

[0069] The hollow insulating skeleton 2 can be made of hard insulating material injection molding, or it can be composed of metal material + functional coating. If the hollow insulating shaft is made of insulating material injection molding, the insulating material includes but is not limited to polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), ABS resin and polyethylene terephthalate (PET). If the hollow insulating skeleton 2 is made of metal material + functional coating, the outer wall of the first insulating section 21 is covered with insulating material + thermal conductive material + corrosion-resistant material coating, and the inner wall is coated with thermal conductive material + corrosion-resistant material coating. The coating method includes but is not limited to spraying, brushing, dipping, etc. The insulating coating material includes but is not limited to resin materials, including phenolic resin, polyester resin, polyamide resin, polyvinyl chloride resin, or a combination of at least two of them. The insulating coating ensures that the outside of the hollow conductor shaft is insulated from the winding core. The thermal conductive material includes at least one of boron nitride, aluminum nitride, silicon carbide, silicon nitride, aluminum oxide, gallium nitride, gallium arsenide, gallium phosphide, zinc oxide, indium phosphide, beryllium oxide, magnesium oxide, and magnesium silicon nitride, which can effectively improve the thermal conductivity of the battery and cooling water. The corrosion-resistant coating inside and outside the shaft body is coated with PTFE emulsion or PFA emulsion, which can effectively prevent the corrosion of the inner wall of the battery shell and the insulating coating by cooling water.

[0070] Furthermore, the hollow conductor skeleton 1 includes a first metal segment 11 and a second metal segment 12. The first metal segment 11 is made of metal material, and the inner wall of the first metal segment 11 is coated with a thermal conductive and anti-corrosion coating; the second metal segment 12 is made of insulating thermal conductive material, and there are two second metal segments 12, one of which is connected to the first end of the first metal segment 11, and the other second metal segment 12 is connected to the second end of the first metal segment 11.

[0071] In an exemplary embodiment of the present application, the second metal segment 12 of the hollow conductor skeleton 1 is fixedly connected to the second insulating segment 22 of the hollow insulating skeleton 2, and the connection methods include but are not limited to welding, sealing, threading, etc. Since the second metal segment 12 and the second insulating segment 22 are both made of insulating thermal conductive materials, the connected joint also has insulating thermal conductive properties, so that the accuracy of the data collected by the temperature sampling nickel sheet 622 and the voltage sampling nickel sheet 623 can be ensured.

[0072] It should be noted that the first insulating segment 21 can also be made of injection molding of hard insulating material, the inner wall of the first insulating segment 21 is coated with a thermal conductive anti-corrosion coating, and the inner wall of the first metal segment 11 is coated with a thermal conductive anti-corrosion coating, and the coating methods include but are not limited to spraying, brushing, and dipping.

[0073] Furthermore, the composite cover plate 61 includes a first plate body 611, a second plate body 612 and a third plate body 613. The first plate body 611 covers part of the first groove 100 and is connected to the first metal segment 11. The first plate body 611 is made of metal material; there are two second plate bodies 612, one of which is connected to the first end of the first plate body 611, and the other is connected to the second end of the first plate body 611. The second plate body 612 is made of insulating material. The second plate body 612 covers another part of the first groove 100 and is connected to at least one of the first metal segment 11 and the second insulating segment 22; the third plate body 613 includes a metal core, the outer surface of the metal core is coated with an insulating coating, one end of the third plate body 613 is connected to the first plate body 611 through one of the second plate bodies 612, and the third plate body 613 covers the second groove 200 and is connected to the first insulating segment 21.

[0074] In an embodiment of the present application, the connection method of the first plate body 611, the second plate body 612 and the third plate body 613 includes but is not limited to mixed injection molding, and the second plate body 612 includes but is not limited to polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), ABS resin and polyethylene terephthalate (PET).

[0075] Preferably, a plurality of first vent holes 211 are provided in the second groove 200 on the first insulating section 21, and a first waterproof breathable membrane 212 is composited on the surface of the plurality of first vent holes 211, and a plurality of second vent holes 6132 are provided on the surface of the third plate body 613. Such a configuration can ensure that the composite cover plate 61 covers the sampling unit 62 in the groove structure, and the second vent holes 6132 are provided to cooperate with the first vent holes 211 to discharge the gas generated by the battery cell to prevent the battery cell from bloating, and a second waterproof breathable membrane 6131 is composited on the surface of the plurality of second vent holes 6132, wherein the first waterproof breathable membrane 212 and the second waterproof breathable membrane 6131 are both breathable and liquid-impermeable, and the first waterproof breathable membrane 212 and the second waterproof breathable membrane 6131 can be made of PP, PE and other materials, and the gas is dissolved and resolved by the concentration difference between the internal and external gases to achieve diffusion at the interface. After the gas is generated during the operation of the soft-pack battery cell, it can be discharged to the cooling pipe inside the serpentine hollow structure A through this structure. Most of the gas produced by the battery cell is carbon dioxide, and cooling water with additives to remove carbon dioxide is passed into the pipeline. The additives include but are not limited to sodium carbonate, organic amine compounds and other carbon dioxide absorbing substances, and the cooling water mother liquid includes but is not limited to alcohol, glycerin, ethylene glycol, etc. The cooling water can continuously absorb the carbon dioxide gas discharged from the battery cell, maintain a high concentration difference of carbon dioxide in the pipeline and the battery cell, and allow the carbon dioxide inside the battery cell to diffuse outward and be discharged.

[0076] Preferably, the third plate 613 is welded to the first insulating section 21, the first plate 611 is welded to the first metal section 11, and the second plate 612 is connected to the first metal section 11 and the second insulating section 22 by a hot melt process. In this way, welding is used at the metal material connection position, and hot melt and other processes are used to connect the insulating component connection position. Welding can enhance the structural strength of the metal material, and hot melt process is simple and convenient for the insulating material, and improves toughness.

[0077] According to another specific embodiment of the present application, a vehicle is also provided, including a soft-pack battery cell, which is the soft-pack battery cell mentioned above.

[0078] The present application also provides a preferred embodiment of a soft-pack battery pack, which has the properties of high safety, high structural strength, high energy density, high cooling efficiency, and high sampling accuracy, so as to solve lithium plating safety problems such as collapse of the center hole of the cylindrical battery cell and large gap between the pole pieces at the innermost corner of the square shell battery cell, thereby improving production efficiency.

[0079] Specifically, the soft pack battery pack includes a battery pack upper cover, a winding core group B, a serpentine hollow sampling long axis A, and a battery pack lower box D. The serpentine hollow sampling long axis A is welded to the battery pack lower box D to serve as a battery pack support beam to improve the structural strength of the battery pack, such as Figure 1-Figure 4As shown, the serpentine hollow sampling long axis A includes a hollow conductor skeleton 1, a hollow insulating skeleton 2, a hollow I-shaped conductor axis 3, a hollow insulating connector 4, a hollow conductive connector 5 and a sampling component 6.

[0080] The hollow conductor skeleton 1 and the hollow I-shaped conductor shaft 3 are used as the series conductive medium between the winding core tabs, the hollow insulating skeleton 2 is used as the structural skeleton of the winding core, and the hollow insulating connector 4 is used as the insulating connector. The hollow conductor skeleton 1 is formed by connecting the first metal segment 11 and the second metal segment 12. The inner wall of the first metal segment 11 is coated with a heat-conducting and anti-corrosion coating. The structure of the hollow conductor skeleton 1 is as follows: Figure 5 The hollow insulating skeleton 2 is formed by connecting the first insulating section 21 and the second insulating section 22. The inner wall of the first insulating section 21 is coated with a heat-conductive anti-corrosion coating, and the outer wall is coated with an insulating coating. A plurality of first air-permeable holes 211 are opened in the second groove 200 of the first insulating section 21, and the first air-permeable holes 211 are covered with a first waterproof and breathable membrane 212. The structure of the hollow insulating skeleton 2 is as shown in FIG. Figure 5 The hollow I-shaped conductor shaft 3 is made of metal conductive material, and the inner wall is coated with a heat-conductive anti-corrosion coating. The cross-section of the hollow conductor skeleton 1, the hollow insulating skeleton 2, and the hollow I-shaped conductor shaft 3 can be circular with a notch on the surface, or can be elliptical.

[0081] The sampling assembly 6 is composed of a composite cover plate 61 and a sampling unit 62. The composite cover plate 61 is formed by alternately connecting a first plate body 611, a second plate body 612 and a third plate body 613 with an insulating coating. The metal material of the first plate body 611 is consistent with the material of the first metal segment 11 in the hollow conductor skeleton 1. The second plate body 612 is an insulating material. The main body material and the coating of the third plate body 613 are consistent with the material of the first insulating segment 21 in the hollow insulating skeleton 2. The third plate body 613 is provided with a plurality of sunken breathable through hole structures (i.e., the second breathable through hole 6132) and covered with a second waterproof breathable membrane 6131. ​​The sampling unit 62 is a wiring harness structure with a sampling function. The sampling main body wiring harness 621 can be a flexible wiring harness plate, etc. The temperature sampling nickel sheet 622 of the wiring harness is welded to the inner surface of the third plate body 613, and the voltage sampling nickel sheet 623 is welded to the inner surface of the first plate body 611.

[0082] Among them, the connection method of the serpentine hollow sampling long axis A is as follows: ① The hollow conductor skeleton 1 and the hollow insulating skeleton 2 are tightly connected through threads at both ends to form a hollow long axis E; ② The sampling component 6 covers the position of the E notch (i.e., the groove structure), penetrates and welds along the contact interface between the third plate body 613 and the first insulating segment 21, and the contact interface between the first plate body 611 and the first metal segment 11, and seals the connection position between the second plate body 612 and the second insulating segment 22, the first metal segment 11 and other insulating components by hot melting and other processes, and in the sampling component 6 Structural adhesive is poured into the through hole surrounded by the hollow long axis E to enhance the structural strength, and finally the sampling hollow long axis is assembled; ③ The first metal segment 11 of the hollow conductor skeleton 1 at the tail end of the adjacent sampling hollow long axis is welded and connected with the hollow I-shaped conductor axis 3, so that the circuit between the two adjacent sampling hollow long axes is conductive; ④ The other end of the hollow I-shaped conductor axis 3 is connected to the hollow insulating connector 4 to achieve local insulation; ⑤ The hollow insulating connector 4 is connected to the hollow conductive connector 5 by threads; ⑥ The hollow conductive connector 5 is welded to the lower box D of the battery pack.

[0083] In the above connection method, the lower box crossbeam is used as the supporting axis, the pole pieces are wound around the axis, and the adjacent pole pieces are connected in series by the conductor axis, eliminating components such as adapters in the battery cell and components such as bar connections between battery cells. This design realizes the soft pack CTP structure and improves the energy density of the pack. The water cooling and sampling systems are integrated to improve space utilization and the energy density of the battery pack. The cooling medium is passed into the serpentine hollow sampling long axis A, and heat is transferred on all sides, which can greatly improve the heat transfer rate and efficiency, and the battery cell is heated evenly; the efficient thermal management system can solve the problems of the battery cell heating too fast during fast charging and too slow preheating in a low temperature environment, and it will also reduce the power consumption of the battery cell for thermal management, which can increase the service life of the battery cell.

[0084] In the soft-pack battery pack of this embodiment, the battery cell is a soft-pack battery. The soft-pack battery core is wound around the first insulating section 21 on the sampling hollow long axis. Several sampling hollow long axes are connected by the hollow I-shaped conductor axis 3 to form a core group. Finally, each soft-pack battery core is wrapped with an aluminum-plastic film. The sampling hollow long axis can be used as a crossbeam of the battery pack and as a support inside the roll, which can improve the structural strength of the soft-pack battery cell. This structure can completely solve the local dynamics of insufficient lithium precipitation problems such as the collapse of the pole piece in the center hole of the cylinder and the large gap between the pole pieces at the corner of the square shell battery cell, and improve the safety performance of the battery cell.

[0085] It should be noted that the soft-pack battery pack can be a cylindrical or square soft-pack battery, which is composed of a soft-pack battery roll core, positive and negative electrode tabs, and an aluminum-plastic film. When the cross-section of the roll core skeleton is circular, the matching soft-pack battery roll core is also circular; when the cross-section of the roll core skeleton is elliptical, the matching soft-pack battery roll core is square.

[0086] The present invention also provides an efficient production method for battery cells and battery packs, and the specific steps are as follows:

[0087] S01: Multiple hollow conductor skeletons 1 and multiple hollow insulating skeletons 2 are tightly connected through threaded structures at both ends to form a hollow long axis E, such as Figure 4 As shown;

[0088] S02: The composite cover plate 61 is covered on the hollow long axis E, and is penetrated and welded along the contact surface between the third plate body 613 and the first insulating section and the first plate body 611 and the first metal section 11. The connection position between the second plate body 612 and the second insulating section 22 and the first metal section 11 and other insulating components is sealed by hot melting or other processes. Structural adhesive is poured into the through hole surrounded by the composite cover plate 61 and the hollow long axis E to enhance the structural strength, and finally the sampling hollow long axis is assembled;

[0089] S03: The sampled hollow long axis is used as a battery core winding needle, and the winding core is wound around the first insulating section 21 (the metal component with an insulating coating in the hollow insulating skeleton 2) on the sampled hollow long axis, so that multiple winding cores can be wound around the hollow long axis at the same time, and the positive and negative pole ears of the winding core are respectively located on both sides of the sampled hollow long axis;

[0090] S04: welding the pole lug of the winding core to the first metal segment 11 (the metal component in the hollow conductor skeleton 1);

[0091] S05: Wrap the aluminum plastic film on each roll core and use the thermal lamination process to achieve sealing, such as Figure 6 , Figure 7 As shown, electrolyte is injected into each soft-pack battery cell and formed;

[0092] S06: Multiple hollow long shafts E with winding cores are serpentine welded through the hollow I-shaped conductor shaft 3, such as Figure 2 As shown;

[0093] S07: The other end of the hollow I-shaped conductor shaft 3 is connected to the hollow insulating connector 4 to achieve partial insulation. The hollow insulating connector 4 is connected to the hollow conductive connector 5 by threads, such as Figure 2 As shown;

[0094] S08: placing the soft-pack battery pack B with the serpentine hollow sampling long axis A as the skeleton in the lower box D of the battery pack, and welding the hollow conductive connector 5 to the lower box of the battery pack;

[0095] S09: Seal and assemble the battery pack upper cover and the battery pack lower box D;

[0096] S10: Structural adhesive is injected into the battery pack to strengthen the fixation of the soft-pack battery cell structure and enhance the strength of the entire pack.

[0097] According to the above-mentioned production method of battery cells and battery packs, the hollow long axis of the sample is used as the supporting structure of the battery pack, which can be used as the supporting structure of the winding operation to improve the structural strength of the soft-pack battery cell, solve the local dynamics of insufficient lithium precipitation problems such as the collapse of the pole piece in the center hole of the cylinder and the large gap between the pole pieces at the corners of the square shell battery cell, and improve the safety performance of the battery cell. The above-mentioned production method adopts a soft-pack battery structure with high structural strength, high energy density, high cooling efficiency, high sampling accuracy and no flatulence effect, and achieves the following

[0098] Beneficial effects:

[0099] 1) High structural strength: The middle of the soft pack battery pack is supported by a hollow long axis and welded to the box body as a crossbeam, and the internal glue of the battery pack is reinforced to further improve the structural strength of the whole pack. By eliminating the module structure, the battery pack structure avoids the shortcomings of the soft pack structure that has poor strength and needs module protection, making the structure reach the same level of strength as the hard shell CTP structure, while giving full play to the advantages of the high energy density of the soft pack, and realizing a high structural strength soft pack CTP.

[0100] 2) High energy density: The serpentine hollow sampling long axis A highly integrates the sampling structure, cooling pipe, electrical connection structure, and the cross beam of the lower box of the battery pack (the inner pipe of the serpentine hollow sampling long axis A is passed through cooling water as a cooling pipe; the serpentine hollow sampling long axis A is welded to the lower box D of the battery pack as a cross beam, such as Figure 3 As shown; the inner wall of the serpentine hollow sampling long axis A is integrated with the wiring harness as a temperature and voltage sampling circuit; the first metal segment 11 in the serpentine hollow sampling long axis A serves as a conductive connecting component of the two battery cells), thereby improving space utilization.

[0101] 3) High-efficiency thermal management system: adopt a hollow structure of the support shaft, and pass the cooling medium into the hollow structure, that is, the cooling medium is passed into the serpentine hollow sampling long axis A, and cooled on all four sides, which greatly improves the cooling rate and refrigeration efficiency, and the battery cell is cooled evenly, solving the problem of reducing the power consumption of the battery cell for thermal management, improving the thermal management efficiency, and extending the life of the battery cell.

[0102] 4) High sampling accuracy: The sampling structure sets the sampling harness inside the serpentine hollow sampling long axis A, and the temperature sampling nickel sheet 622 is welded under the composite cover plate 61 to collect the real temperature inside the battery cell, providing effective support for the fast charging capability of the battery cell.

[0103] 5) Non-bloating soft-pack battery cell structure: The exhaust structure is set on the tube wall of the serpentine hollow sampling long axis A, and the gas generated by the battery cell is discharged through the exhaust structure. The gas is dissolved and resolved by the concentration difference between the internal and external gases to achieve diffusion at the interface. After the gas is generated during the operation of the soft-pack battery cell, it can be discharged into the cooling pipe inside the serpentine hollow sampling long axis A through this structure. Most of the gas produced by the battery cell is carbon dioxide, and cooling water with additives to remove carbon dioxide is passed into the pipe. The cooling water can continuously absorb the carbon dioxide gas discharged from the battery cell, maintain a high concentration difference of carbon dioxide in the pipe and the battery cell, and make the carbon dioxide inside the battery cell diffuse and discharge outward, solving the problem of soft-pack battery pack inflation.

[0104] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0105] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0106] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A soft pack battery cell, characterized in that: include: A soft-pack battery roll core, wherein the soft-pack battery roll core has a positive electrode tab and a negative electrode tab; A winding core skeleton, the winding core skeleton comprising a hollow insulating skeleton (2) and a hollow conductor skeleton (1), the hollow conductor skeleton (1) being two, one of the hollow conductor skeletons (1) being connected to a first end of the hollow insulating skeleton (2), and the other of the hollow conductor skeletons (1) being connected to a second end of the hollow insulating skeleton (2); The outer surface of the winding core skeleton is provided with a groove structure, the groove structure comprising a first groove (100) provided on the outer surface of the hollow conductor skeleton (1), and a second groove (200) provided on the outer surface of the hollow insulating skeleton (2), wherein the first groove (100) is arranged in communication with the second groove (200), and a ventilation hole is provided on the second groove (200); The soft-pack battery core is wound on the core skeleton, the positive electrode tab is connected to one of the hollow conductor skeletons (1), and the negative electrode tab is connected to the other hollow conductor skeleton (1).

2. The soft pack battery cell according to claim 1, characterized in that: The roll core skeleton also includes: A sampling component (6), the sampling component (6) is connected to at least one of the hollow insulating skeleton (2) and the hollow conductor skeleton (1), and the sampling component (6) is used to collect at least one of the temperature and the voltage of the soft-pack battery unit.

3. The soft pack battery cell according to claim 2, characterized in that: The sampling component (6) covers the groove structure.

4. The soft pack battery cell according to claim 3, characterized in that: The sampling component (6) comprises: A composite cover plate (61), the composite cover plate (61) covers the groove structure and is connected to at least one of the hollow insulating skeleton (2) and the hollow conductor skeleton (1); A sampling unit (62), the sampling unit (62) being arranged on a side of the composite cover plate (61) close to the groove structure, at least a portion of the sampling unit (62) extending into the groove structure, and the sampling unit (62) being used to collect at least one of the temperature and the voltage of the soft-pack battery unit.

5. The soft pack battery cell according to claim 4, characterized in that: At least one of the groove structure and the composite cover plate (61) is provided with the ventilation hole.

6. The soft pack battery cell according to claim 5, characterized in that: The ventilation through hole is covered with a waterproof and breathable membrane.

7. The soft pack battery cell according to claim 4, characterized in that: The sampling unit (62) comprises a sampling main body harness (621), and a temperature sampling nickel sheet (622) and a voltage sampling nickel sheet (623) connected to the sampling main body harness (621); the temperature sampling nickel sheet (622) is arranged corresponding to the hollow insulating skeleton (2), and the voltage sampling nickel sheet (623) is arranged corresponding to the hollow conductor skeleton (1).

8. The soft pack battery cell according to claim 7, characterized in that: The sampling main wire harness (621) is a sampling wire harness plate, on which the temperature sampling nickel sheet (622) and the voltage sampling nickel sheet (623) are arranged, and the sampling wire harness plate is connected to a side of the composite cover plate (61) close to the groove structure.

9. The soft pack battery cell according to claim 4, characterized in that: Structural adhesive is filled between the composite cover plate (61) and the roll core frame.

10. The soft pack battery cell according to claim 1, characterized in that: The outer surface of the soft-pack battery core is wrapped with an aluminum-plastic film, and the aluminum-plastic film is sealed and connected to the soft-pack battery core through a thermal composite process.

11. The soft pack battery cell according to claim 1, characterized in that: At least one of the hollow insulating skeleton (2) and the hollow conductor skeleton (1) is used for passing cooling liquid.

12. A vehicle, characterized in that: The vehicle includes a soft-pack battery cell, and the soft-pack battery cell is the soft-pack battery cell according to any one of claims 1-11.

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