Upper cover of battery pack, manufacturing method of upper cover, battery pack and electric equipment

Abstract

The invention provides an upper cover of a battery pack, a manufacturing method of the upper cover, the battery pack and electric equipment. The upper cover of the battery pack comprises: an inner cover body made of a composite material; the outer cover body comprises an outer cover body formed outside the inner cover body, a base material of the inner cover body is welded with a material of the outer cover body, the inner cover body is provided with a plurality of first through holes penetrating through the thickness direction of the inner cover body, and the outer cover body further comprises a plurality of connecting parts corresponding to the first through holes; and each connecting part penetrates through the corresponding first through hole and is integrally formed with the outer cover body. The upper cover of the battery pack can solve the problems that a plastic upper cover is difficult to lighten and low in rigidity, and the strength of the bonding surfaces of different material layers of a plurality of layers of upper covers is not high enough. The battery pack comprises the upper cover. The electric equipment comprises the battery pack. The manufacturing method of the battery pack comprises the following steps: acting the material of the outer cover body on the surface of the inner cover body in a molten state, and solidifying to form the outer cover body, so that the outer cover body is welded with the inner cover body.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a top cover of a battery pack and a manufacturing method thereof, a battery pack and an electrical device. Background Art

[0002] In the battery pack of the related art, non-metallic upper covers are often used, such as composite upper covers, plastic upper covers, or multi-layer upper covers containing different non-metallic material layers. However, the above non-metallic upper covers have their own problems. The material cost of the composite upper cover is relatively high and the processing cycle is relatively long; conventional processing technology is difficult to process plastic upper covers with thin walls, which are heavy and not conducive to lightweighting of the upper cover, and the plastic upper cover itself has low rigidity and is easy to deform; in the multi-layer upper cover, the strength of the joint surface of different material layers is not high enough.

[0003] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0004] The purpose of the present application is to provide a battery pack upper cover and a manufacturing method thereof, a battery pack and an electrical device, aiming to solve the problems of high material cost of composite material upper covers, difficulty in lightweighting plastic upper covers, low rigidity of the plastic upper covers, and insufficient strength of the bonding surfaces of different material layers of multi-layer upper covers.

[0005] The first aspect of the present application provides a top cover of a battery pack, comprising: an inner cover body made of a composite material; and The outer cover comprises an outer cover body formed outside the inner cover, wherein the base material of the inner cover is welded to the material of the outer cover body; Among them, the inner cover body has a plurality of first through holes penetrating through its thickness direction, and the outer cover body also includes a plurality of connecting parts arranged corresponding to the plurality of first through holes, each of the connecting parts passes through the corresponding first through hole and is formed integrally with the outer cover body.

[0006] In the upper cover of the battery pack provided in the present application, the inner cover is made of a composite material. The composite material itself has a high rigidity and can be used as the skeleton of the upper cover to improve the rigidity of the upper cover, reduce the deformation of the upper cover after molding, and meet the requirements of the contour of the upper cover battery pack. In addition, the inner cover made of the composite material is conducive to the lightweight of the upper cover. In addition, the material of the outer cover body is welded to the base material of the inner cover body. At the connection position between the inner cover body and the outer cover body, the inner cover body and the outer cover body can be formed as one piece without producing an obvious interface, which is conducive to improving the bonding strength between the inner cover body and the outer cover body. The inherent strength and the strength after creep of this type of upper cover are significantly higher than those of an upper cover made of a single material.

[0007] Since the inner cover can make the upper cover have sufficient rigidity and reduce the thermal deformation of the upper cover, and there is no obvious interface between the inner cover and the outer cover, the airtightness is good, which is conducive to reducing the risk of air leakage from between the inner cover and the outer cover, thereby improving the reliability of thermal runaway protection measures. During the thermal runaway of the battery pack, the material of the outer cover and the base material of the inner cover can expand rapidly under the action of high-temperature and high-pressure gas to form a foam insulation layer, which is conducive to preventing heat from spreading rapidly to the surrounding area of ​​the battery pack.

[0008] The material of the outer cover body can not only form a welding area through the outer cover body body and the base material of the inner cover body, but also enter and pass through multiple first through holes to form multiple connecting parts. After the connecting parts are cooled and solidified, they can form a limited connecting structure similar to riveting, which is beneficial to improve the connection strength between the outer cover body and the inner cover body.

[0009] In some embodiments of the upper cover, each of the connecting parts fills up the inner space of the corresponding first through hole, and the base material of the inner cover body is welded to the material of the connecting part.

[0010] In the upper cover of the present embodiment, the outer cover body can be welded to the base material of the inner cover body not only through the material of the outer cover body main body, but also through the material of the connecting part filling the internal space of the first through hole, thereby further improving the bonding strength between the inner cover body and the outer cover body.

[0011] In some embodiments of the upper cover, the upper cover has a flange formed by the inner cover body and the outer cover body, and the flange is provided with a connecting hole, which passes through the inner cover body and the outer cover body along the thickness direction of the flange, and the connecting hole is configured to pass through the connecting piece required to connect the upper cover and the box shell of the battery pack.

[0012] In the upper cover of the present embodiment, the connecting hole passes through the inner cover body and the outer cover body, and the hole wall of the connecting hole is formed by the inner cover body and the outer cover body. The peripheral position of the connecting hole not only has a composite material layer as a skeleton, but also has a welding area of ​​the inner cover body and the outer cover body, so that the upper cover has sufficient rigidity and strength at the peripheral position of the connecting hole, which is beneficial to reduce the deformation of the upper cover when the connecting piece acts on the upper cover.

[0013] In some embodiments of the upper cover, the outer cover body further includes a plurality of reinforcing ribs, and the plurality of reinforcing ribs are disposed on the flange and are integrally formed with the outer cover body.

[0014] As part of the outer cover, the multiple reinforcing ribs are made of the same material as the outer cover body and can be integrally formed with the outer cover body. Based on the usual plastic processing technology, such as injection molding, the processing of reinforcing ribs of complex shapes can be achieved. Considering that the flange is usually used as the locking surface of the upper cover, the multiple reinforcing ribs arranged on the edge of the flange can improve the rigidity of the locking surface of the upper cover and reduce the rigidity of the locking surface after the upper cover is connected to the box shell of the battery pack, without the need to set additional metal strips.

[0015] In the upper cover of some embodiments, each of the reinforcing ribs includes a first rib extending along an edge of the flange and / or a second rib extending around the connecting hole.

[0016] The first rib extends along the edge of the flange, which can improve the bending stiffness of its extended area and the nearby area. The second rib extends around the connecting hole, which can improve the bending stiffness of the peripheral position of the connecting hole. Therefore, the upper cover of this embodiment can improve the stiffness of the edge area of ​​the upper cover and reduce the deformation of the edge area of ​​the upper cover.

[0017] In some embodiments of the upper cover, the middle position of the upper cover includes a raised portion relative to the flange, and at least one of the reinforcing ribs includes a third rib, one end of the third rib is connected to the raised portion, and the other end is connected to the first rib or the second rib.

[0018] The third rib is connected between the raised portion of the upper cover and the first rib, which can improve the bending rigidity of the upper cover at the connection position between the raised portion and the edge portion, thereby further improving the rigidity of the upper cover and reducing deformation of the upper cover.

[0019] In some embodiments of the upper cover, the base material of the inner cover body includes a thermoplastic material, and / or the material of the outer cover body includes a thermoplastic material.

[0020] The base material of the inner cover is made of thermoplastic material, which is conducive to the welding of the base material of the inner cover with the outer cover in a heated state. The outer cover is made of thermoplastic material, which can appropriately reduce the cost of the upper cover material compared to the upper cover made entirely of composite materials. During thermal runaway of the battery pack, at least one of the material of the outer cover and the base material of the inner cover can expand rapidly under the action of high-temperature and high-pressure gas to form a foamed insulation layer, which helps to prevent heat from spreading rapidly to the surrounding area of ​​the battery pack.

[0021] In the upper cover of some embodiments, the base material of the inner cover body and / or the material of the outer cover body includes at least one of the following materials: PP, PA, PBT; and / or, the reinforcing material of the composite material includes at least one of the following materials: glass fiber, carbon fiber, talcum powder; and / or, the composite material also includes flame retardant material and / or toughening material.

[0022] By adding flame retardant materials to the composite materials, the ability of the upper cover to resist thermal runaway can be improved, and by adding toughening materials to the composite materials, the toughness of the upper cover can be improved.

[0023] In the upper cover of some embodiments, the base material of the inner cover body and the material of the outer cover body are the same material.

[0024] The use of the same material for the base material of the inner cover and the material of the outer cover helps to better integrate the base material of the inner cover and the material of the outer cover, which is beneficial to further improve the bonding strength between the inner cover and the outer cover.

[0025] In some embodiments of the upper cover, the outer cover body is formed on one side or both sides of the inner cover body along its own thickness direction.

[0026] The outer cover body can form a welding area with the inner cover body on each side of the inner cover body along its own thickness direction, which is conducive to sufficient bonding strength between the inner cover body and the outer cover body. In the case where the outer cover body made of thermoplastic material is formed on both sides of the inner cover body along its own thickness direction, the outer cover body on one side of the inner cover body along its own thickness direction faces the inside of the battery pack. During the thermal runaway of the battery pack, the high-temperature and high-pressure gas first contacts the outer cover body. The outer cover body made of thermoplastic material can expand rapidly at high temperature to form the aforementioned foam insulation layer.

[0027] In some embodiments of the upper cover, the outer cover body is completely covered on the outer surface of the inner cover body.

[0028] For the upper cover of the present embodiment, the outer sides of the two end faces of the inner cover body along its own thickness direction and the side faces parallel to its own thickness direction are covered with the outer cover body. The outer cover body can form a welding area with the inner cover body on each outer surface of the inner cover body, which is beneficial to ensure that the inner cover body and the outer cover body have sufficient bonding strength.

[0029] In some embodiments of the upper cover, the inner cover body and the outer cover body form a multi-layer structure, wherein the thickness of the material of each layer of the inner cover body is 0.05mm~50mm, and / or the thickness of the material of each layer of the outer cover body is 0.05mm~50mm.

[0030] The thickness of each layer of the inner cover material and the thickness of each layer of the outer cover material can be specifically determined according to the size, cost and performance requirements of the battery pack. Within the above value range, the thickness of each material layer of the upper cover can adapt to the size, cost and performance requirements of a common battery pack. By reasonably matching the thickness of the thermoplastic material layer and the composite material layer, the upper cover can have high strength, rigidity and low cost at the same time.

[0031] A second aspect of the present application provides a battery pack, comprising: Battery pack; casing; and The upper cover described in the first aspect of the present application is snap-fitted to the box shell, and the battery pack is arranged in a space formed by the box shell and the upper cover.

[0032] The battery pack provided in this application has the same advantages as the upper cover provided in this application.

[0033] A third aspect of the present application provides an electrical device, comprising the battery pack described in the second aspect of the present application, wherein the battery pack is used to provide power to the electrical device.

[0034] The electrical equipment provided in this application has the same advantages as the battery pack provided in this application.

[0035] The fourth aspect of the present application provides a method for manufacturing the upper cover according to the first aspect of the present application, comprising: applying the material of the outer cover body to the surface of the inner cover body in a molten state, and solidifying to form the outer cover body, so that the material of the outer cover body is welded to the base material of the inner cover body.

[0036] In the manufacturing method of the upper cover of the present application, the material of the outer cover body is applied to the surface of the inner cover body in a molten state, and the base material of the inner cover body at the connection position with the outer cover body body is also melted under the action of the molten material of the outer cover body, and the formed upper cover has a welding area between the outer cover body and the inner cover body. Therefore, the manufacturing method has the same advantages as the upper cover provided in the present application.

[0037] In some embodiments of the manufacturing method of the upper cover, the material of the outer cover body is a thermoplastic material, and the material of the outer cover body is applied to the surface of the inner cover body in a molten state, including: using the inner cover body as the core mold of the injection mold of the outer cover body, and then injecting into the inner cavity of the injection mold.

[0038] In the manufacturing method of the upper cover of the present embodiment, an outer cover body with a more complex structure can be processed by injection molding, and the inner cover body itself is used as a part of the injection mold. When the material of the outer cover body is completely cooled and solidified, the outer cover body and the inner cover body can be welded to each other to obtain an integrally formed upper cover.

[0039] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0041] Figure 1 This is a schematic diagram of the structure of electrical equipment in some embodiments of the present application.

[0042] Figure 2 A schematic diagram of the structure of a battery pack provided for some embodiments of the present application.

[0043] Figure 3 This is a schematic diagram of the structure of the upper cover of the battery pack of some embodiments of the present application.

[0044] Figure 4 This is a schematic diagram of the top structure of the upper cover of some embodiments of the present application.

[0045] Figure 5 This is a schematic structural diagram of the inner cover body of the upper cover of some embodiments of the present application.

[0046] Figure 6 for Figure 4 The AA cross-sectional structure diagram of the upper cover shown in FIG. Figure 5 The inner cover shown.

[0047] Figure 7 for Figure 6 The enlarged structural schematic diagram of the upper cover at B is shown.

[0048] Figure 8 Schematic diagram of the structure of the inner cover body of the upper cover of other embodiments of the present application.

[0049] Fig. 9 This is a partially enlarged schematic diagram of the cross-section of the upper cover of some embodiments of the present application, wherein the inner cover body is Figure 8 The inner cover shown.

[0050] Figures 1 to 9 In the figure, each reference numeral represents: D. Electrical equipment; B. Battery pack; C. Box; 1. Upper cover; 11. Inner cover body; 111. First through hole; 12. Outer cover body; 121. Outer cover body body; 122. Connecting part; 123. Reinforcing rib; 1231. First rib; 1232. Second rib; 1233. Third rib; 13. Connecting hole; 131. Second through hole; 14. Raised part; 15. Flange; 2. Battery pack; 20. Battery cell; 3. Box shell. DETAILED DESCRIPTION

[0051] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0052] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0053] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0054] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0055] In the process of forming this application, the inventors found that, as described in the background technology, the material cost of the composite material upper cover is high and the processing cycle is long. Conventional processing technology makes it difficult to process plastic upper covers with thin walls, and the weight is large, which is not conducive to lightweighting of the upper cover. In addition, the plastic upper cover itself has low rigidity and is easy to deform. In a multi-layer upper cover, the strength of the joint surface of different material layers is not high enough. The bonding method of different material layers will not only affect the strength of the joint surface, but also the airtightness of the joint surface. Once the joint surface is deflated, it may affect the eruption of high-temperature and high-pressure gas from the battery cell explosion-proof valve, thereby causing the thermal runaway protection measures to fail.

[0056] Based on this, the present application proposes a top cover for a battery pack, which, by improving the connection method of different material layers in the top cover, helps solve the problems of high material cost of the composite material top cover, difficulty in lightweighting the plastic top cover, low rigidity itself, and insufficient strength of the bonding surfaces of different material layers in the multi-layer top cover.

[0057] Furthermore, the present application also proposes a battery pack including the upper cover. Furthermore, the present application also proposes an electrical device including the battery pack. Furthermore, the present application also proposes a method for manufacturing the upper cover.

[0058] The battery pack is configured to provide electrical energy to electrical devices. Electrical devices may be, but are not limited to, mobile phones, portable devices, laptop computers, battery vehicles, electric vehicles, ships, spacecraft, electric toys, and electric tools, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0059] A battery pack is a single physical module that includes one or more battery cells to provide higher voltage and capacity. A battery pack generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0060] A battery cell refers to the smallest unit that makes up a battery. In the present application, battery cells may include lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application. Battery cells may be flat, rectangular, or in other shapes, which are not limited in the embodiments of the present application. Battery cells are generally packaged as square battery cells and soft-pack battery cells, which are not limited in the embodiments of the present application.

[0061] The battery pack also includes electrical components such as BDU and BMS. BDU has multiple functions such as charge and discharge control, power-on control of high-voltage components, circuit overload and short-circuit protection, high-voltage sampling and low-voltage control. Its main function is to provide power management and protection for the high-voltage system of electrical equipment to ensure the stable operation of the high-voltage system. BMS is mainly used to monitor parameters such as voltage, temperature and current of battery cells, realize balanced charge and discharge, protection and fault diagnosis of batteries, and ensure the safety and stability of the battery pack. Electrical components such as BDU and BMS are carried and fixed on the top of the battery pack through electrical component brackets.

[0062] like Figures 3 to 9As shown, the upper cover 1 of the battery pack B provided in the embodiment of the present application includes an inner cover body 11 and an outer cover body 12. The inner cover body 11 is made of a composite material. The outer cover body 12 includes an outer cover body main body 121 formed on the outside of the inner cover body 11, and the base material of the inner cover body 11 is welded with the material of the outer cover body main body 121. Among them, the inner cover body 11 has a plurality of first through holes 111 that penetrate through its thickness direction, and the outer cover body 12 also includes a plurality of connecting parts 122 corresponding to the plurality of first through holes 111, and each connecting part 122 passes through the corresponding first through hole 111 and is integrally formed with the outer cover body main body 121.

[0063] The inner cover 11 can be formed into a desired shape by molding or other methods. The base material of the inner cover 11 can be the same or different from the outer cover 12. The base material of the inner cover 11 can be specifically determined according to the different cost and performance requirements of the battery pack, and can be welded with the thermoplastic material of the outer cover 12. The outer cover 12 can be formed by injection molding, hot pressing or other processing methods that can make the thermoplastic material of the outer cover 12 act on the surface of the inner cover 11 in a molten state.

[0064] In the upper cover 1 of the battery pack provided in the embodiment of the present application, the inner cover 11 is made of a composite material. The composite material itself has a high rigidity and can be used as the skeleton of the upper cover 1 to improve the rigidity of the upper cover 1 and reduce the deformation of the upper cover 1 after molding, so that the upper cover 1 meets the requirements of the battery pack contour. In addition, the inner cover 11 made of composite material is conducive to the lightweight of the upper cover 1. In addition, the material of the outer cover body 121 is welded to the base material of the inner cover 11. At the connection position between the inner cover 11 and the outer cover 12, the inner cover 11 and the outer cover 12 can be formed as one piece without producing an obvious interface, which is conducive to improving the bonding strength between the inner cover 11 and the outer cover 12. The self-strength and the strength after creep of this form of upper cover 1 are significantly higher than those of an upper cover made of a single material.

[0065] Because the inner cover body 11 can make the upper cover 1 have sufficient rigidity and reduce the thermal deformation of the upper cover 1, and no obvious boundary surface is generated between the inner cover body 11 and the outer cover body 12, the airtightness is good, which is beneficial to reduce the risk of air leakage from between the inner cover body 11 and the outer cover body 12, thereby improving the reliability of the thermal runaway protection measures.

[0066] The material of the outer cover body 12 can not only form a welding area through the outer cover body main body 121 and the base material of the inner cover body 11, but also can enter and pass through the multiple first through holes 111 to form multiple connecting parts 122. After the connecting parts 122 are cooled and solidified, they can form a limiting connection structure similar to riveting, which is beneficial to improve the connection strength between the outer cover body 12 and the inner cover body 11.

[0067] like Figure 3 , Figure 4 , Figure 8 and Fig. 9As shown, in some embodiments of the upper cover 1 , each connection portion 122 fills up the inner space of the corresponding first through hole 111 , and the base material of the inner cover body 11 is welded to the material of the connection portion 122 .

[0068] In the upper cover 1 of the present embodiment, the outer cover body 12 can not only be welded to the base material of the inner cover body 11 through the material of the outer cover body main body 121, but also can be welded to the base material of the inner cover body 11 through the material of the connecting portion 122 that fills the internal space of the first through hole 111, thereby further improving the bonding strength between the inner cover body 11 and the outer cover body 12.

[0069] like Figure 3 , Figure 4 , Figure 7 and Fig. 9 As shown, in some embodiments of the upper cover 1, the upper cover 1 has a flange 15 formed by an inner cover body 11 and an outer cover body 12, and a connecting hole 13 is provided on the flange 15. The connecting hole 13 passes through the inner cover body 11 and the outer cover body 12 along the thickness direction of the flange 15, and the connecting hole 13 is configured to pass through the connecting piece required to connect the upper cover 1 and the box shell 3 of the battery pack B.

[0070] In the upper cover 1 of the present embodiment, the connecting hole 13 passes through the inner cover body 11 and the outer cover body 12, and the hole wall of the connecting hole 13 is formed by the inner cover body 11 and the outer cover body 12. The peripheral position of the connecting hole 13 not only has a composite material layer as a skeleton, but also has a fusion area of ​​the inner cover body 11 and the outer cover body 12, so that the upper cover 1 has sufficient rigidity and strength at the peripheral position of the connecting hole 13, which is beneficial to reduce the deformation of the upper cover 1 when the connecting member acts on the upper cover 1.

[0071] In addition, in the process of forming this application, the inventors found that it is difficult to add complex reinforcing ribs to the locking surface of the composite material upper cover, and the locking surface of the plastic upper cover is insufficiently rigid. Both upper covers made of a single material need to be provided with additional metal strips to enhance the rigidity of the locking surface after the connector connects the upper cover to the battery pack shell.

[0072] Based on this, Figure 3 , Figure 4 , Figure 7 and Fig. 9 As shown, in some embodiments of the upper cover 1 , the outer cover body 12 further includes a plurality of reinforcing ribs 123 , which are disposed on the flange 15 and are integrally formed with the outer cover body 121 .

[0073] As a part of the outer cover 12, the multiple reinforcing ribs 123 are made of the same material as the outer cover body 121, and can be integrally formed with the outer cover body 121. Based on the usual plastic processing technology, such as injection molding, the processing of the reinforcing ribs 123 with complex shapes can be realized. Considering that the flange 15 is usually used as the locking surface of the upper cover 1, the multiple reinforcing ribs 123 arranged on the edge of the flange 15 can improve the rigidity of the locking surface of the upper cover 1, and reduce the rigidity of the locking surface after the upper cover 1 is connected to the box shell 3 of the battery pack B, without the need to set an additional metal strip.

[0074] like Figure 3 and Figure 4 As shown, in some embodiments of the upper cover 1 , each reinforcing rib 123 includes a first rib 1231 extending along the edge of the upper cover 1 and / or a second rib 1232 extending around the connecting hole 13 .

[0075] The first rib 1231 extends along the edge of the flange 15, which can improve the bending stiffness of its extended area and the nearby area. The second rib 1232 extends around the connecting hole 13, which can improve the bending stiffness of the peripheral position of the connecting hole 13. Therefore, the upper cover 1 of this embodiment can improve the stiffness of the edge area of ​​the upper cover 1 and reduce the deformation of the edge area of ​​the upper cover 1.

[0076] like Figure 3 , Figure 4 and Figure 6 As shown, in some embodiments of the upper cover 1, the middle position of the upper cover 1 includes a raised portion 14 raised relative to the flange 15, and at least one reinforcing rib 123 includes a third rib 1233, one end of the third rib 1233 is connected to the raised portion 14, and the other end is connected to the first rib 1231 or the second rib 1232.

[0077] The third rib 1233 is connected between the raised portion 14 of the upper cover 1 and the first rib 1231 , which can improve the bending stiffness of the upper cover 1 at the connection position between the raised portion 14 and the edge portion, thereby further improving the stiffness of the upper cover 1 and reducing deformation of the upper cover 1 .

[0078] In some embodiments of the upper cover 1, the base material of the inner cover body 11 includes a thermoplastic material.

[0079] In some embodiments of the upper cover 1 , the material of the outer cover body 12 includes thermoplastic material.

[0080] The base material of the inner cover 11 is made of thermoplastic material, which is conducive to the welding of the base material of the inner cover 11 with the outer cover 12 in a heated state. The outer cover 12 is made of thermoplastic material, which can appropriately reduce the cost of the upper cover material compared to the upper cover made entirely of composite materials. During the thermal runaway of the battery pack B, at least one of the material of the outer cover 12 and the base material of the inner cover 11 can expand rapidly under the action of high-temperature and high-pressure gas to form a foamed insulation layer, which helps to prevent heat from spreading rapidly to the surrounding area of ​​the battery pack B.

[0081] In some embodiments of the upper cover 1, the base material of the inner cover body 11 and / or the material of the outer cover body 12 includes at least one of the following materials: PP (Polypropylene), PA (Polyamide, i.e. nylon), PBT (Polybutyleneterephthalate).

[0082] In the upper cover 1 of some embodiments, the reinforcing material of the composite material includes at least one of the following materials: glass fiber, carbon fiber, and talcum powder.

[0083] In the upper cover 1 of some embodiments, the composite material further includes a flame retardant material and / or a toughening material.

[0084] The flame retardant material is used to inhibit or delay the combustion of the composite material, and may be, for example, aluminum oxide. The toughening material is used to enhance the toughness of the composite material, and may be, for example, a plastic toughening agent.

[0085] By adding flame retardant materials to the composite material, the ability of the upper cover 1 to resist thermal runaway can be improved, and by adding toughening materials to the composite material, the toughness of the upper cover 1 can be improved.

[0086] In some embodiments of the upper cover 1 , the base material of the inner cover body 11 and the material of the outer cover body 12 are the same material.

[0087] Using the same material for the base material of the inner cover body 11 and the outer cover body 12 helps to better integrate the base material of the inner cover body 11 and the outer cover body 12, which is beneficial to further improve the bonding strength between the inner cover body 11 and the outer cover body 12.

[0088] like Figure 3 , Figure 4 , Figure 6 , Figure 7 and Fig. 9 As shown, in some embodiments of the upper cover 1, the outer cover body 121 is formed on one side or both sides of the inner cover body 11 along its own thickness direction.

[0089] The outer cover body 121 can form a welding area with the inner cover body 11 on each side of the inner cover body 11 along the thickness direction, which is conducive to sufficient bonding strength between the inner cover body 11 and the outer cover body 12. In the case where the outer cover body 121 made of plastic material is formed on both sides of the inner cover body 11 along the thickness direction, the outer cover body 121 on one side of the inner cover body 11 along the thickness direction faces the inside of the battery pack B. During the thermal runaway of the battery pack B, the high-temperature and high-pressure gas first contacts the outer cover body 121. The outer cover body 121 made of thermoplastic material can expand rapidly at high temperature to form the aforementioned foam insulation layer.

[0090] like Figure 3 , Figure 4 , Figure 6 , Figure 7 and Fig. 9 As shown, in some embodiments of the upper cover 1 , the outer cover body 121 completely covers the outer surface of the inner cover body 11 .

[0091] For the upper cover 1 of the present embodiment, the outer sides of the two end faces of the inner cover body 11 along its own thickness direction and the side faces parallel to its own thickness direction are covered with the outer cover body 121. The outer cover body 121 can form a welding area with the inner cover body 11 on each outer surface of the inner cover body 11, which is beneficial to ensure that the inner cover body 11 and the outer cover body 12 have sufficient bonding strength.

[0092] In some embodiments of the upper cover 1, the inner cover body 11 and the outer cover body 12 form a multi-layer structure, wherein the thickness of the material of each layer of the inner cover body 11 is 0.05mm~50mm, and / or the thickness of the material of each layer of the outer cover body 12 is 0.05mm~50mm.

[0093] The thickness of the material of each layer of the inner cover 11 and the thickness of the material of each layer of the outer cover 12 can be specifically determined according to the size, cost and performance requirements of the battery pack B. Within the above value range, the thickness of each material layer of the upper cover 1 can adapt to the size, cost and performance requirements of the general battery pack B. By reasonably matching the thickness of the thermoplastic material layer and the composite material layer, the upper cover 1 can have high strength, rigidity and low cost at the same time.

[0094] like Figure 2 As shown, the battery pack B provided in the embodiment of the present application includes a battery pack 2, a box shell 3 and an upper cover 1 provided in the embodiment of the present application. The upper cover 1 is snap-fitted to the box shell 3, and the battery pack 2 is arranged in the space formed by the box shell 3 and the upper cover 1.

[0095] The battery pack provided in the embodiment of the present application has the same advantages as the upper cover provided in the embodiment of the present application.

[0096] like Figure 1As shown, the electric device D according to the embodiment of the present application includes the battery pack B according to the embodiment of the present application, and the battery pack B is used to provide power to the electric device D.

[0097] The electrical equipment provided in the embodiment of the present application has the same advantages as the battery pack provided in the embodiment of the present application.

[0098] The manufacturing method of the upper cover 1 provided in the embodiment of the present application includes: applying the material of the outer cover 12 in a molten state to the surface of the inner cover 11 and solidifying to form the outer cover 12, so that the material of the outer cover body 121 is welded to the base material of the inner cover 11.

[0099] In the manufacturing method of the upper cover of the embodiment of the present application, the material of the outer cover body 12 is applied to the surface of the inner cover body 11 in a molten state, and the substrate of the inner cover body 11 at the connection position with the outer cover body main body 121 is also melted under the action of the material of the outer cover body 12 in a molten state, and the formed upper cover 1 has a welding area between the outer cover body 12 and the inner cover body 11. Therefore, this manufacturing method has the same advantages as the upper cover provided in the embodiment of the present application.

[0100] In the manufacturing method of the upper cover 1 in some embodiments, the material of the outer cover body 12 is a thermoplastic material, and the material of the outer cover body 12 is applied to the surface of the inner cover body 11 in a molten state, including: using the inner cover body 11 as the core mold of the injection mold of the outer cover body 12, and then injecting into the inner cavity of the injection mold.

[0101] In the manufacturing method of the upper cover 1 of the present embodiment, an outer cover body 12 with a more complex structure can be processed by injection molding, and the inner cover body 11 itself serves as a part of the injection mold. When the material of the outer cover body 12 is completely cooled and solidified, the outer cover body 12 and the inner cover body 11 can be welded to each other to obtain an integrally formed upper cover 1.

[0102] The following combination Figures 1 to 9 The upper cover 1 of the battery pack B, the battery pack B having the upper cover 1, the electrical device D having the battery pack B, and the manufacturing method of the upper cover 1 of some embodiments of the present application are described in more detail.

[0103] Please refer to Figure 1 . Figure 1 The schematic diagram of the structure of the electric device vehicle D provided in some embodiments of the present application. The vehicle D can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. Figure 2 The vehicle D is provided with a battery pack B inside, and the battery pack B can be provided at the bottom, head, or tail of the vehicle D. The battery pack B can be used for powering the vehicle D, for example, it can be used as an operating power source of the vehicle D.

[0104] In some embodiments of the present application, the battery pack B can not only serve as the operating power source of the vehicle D, but also serve as the driving power source of the vehicle D, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle D.

[0105] Figure 2 The schematic diagram of the structure of the battery pack B provided in some embodiments of the present application. The battery pack B includes a battery group 2, a box shell 3 and an upper cover 1 provided in an embodiment of the present application.

[0106] like Figure 2 As shown, the upper cover 1 is buckled and connected to the box shell 3, and the battery pack 2 is arranged in the space formed by the box shell 3 and the upper cover 1. In the above embodiments, the box body C composed of the upper cover 1 and the box shell 3 is a rectangular parallelepiped as a whole. In embodiments not shown in the figure, the box body C can also be other shapes, such as a cylinder. In some embodiments, the box body can be used as part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0107] In the battery pack B, the battery pack 2 may be connected in series, in parallel or in a mixed connection. The battery pack 2 may be directly connected in series, in parallel or in a mixed connection, and then the battery pack 2 composed of the battery pack 2 may be accommodated in the space formed by the box shell 3 and the upper cover 1.

[0108] Figure 3 Schematic diagram of the structure of the upper cover 1 of the battery pack B in some embodiments of the present application. Figure 3 As shown, the upper cover 1 of the battery pack B includes an inner cover body 11 and an outer cover body 12 .

[0109] The inner cover 11 is made of a composite material whose base material is a thermoplastic material. The outer cover 12 is made of a thermoplastic material, and the outer cover 12 includes an outer cover body 121 formed outside the inner cover 11, and the base material of the inner cover 11 and the material of the outer cover body 121 are welded.

[0110] The base material of the inner cover 11 and the material of the outer cover 12 can be at least one of the following thermoplastic materials: PP, PA, PBT. The reinforcing material of the composite material includes at least one of the following materials: glass fiber, carbon fiber, talcum powder. The composite material also includes flame retardant materials and toughening materials.

[0111] The base material of the inner cover 11 and the outer cover 12 are made of the same material.

[0112] The outer cover body 121 is formed on one or both sides of the inner cover body 11 along its thickness direction. Figure 3 and Figure 4 , Figure 7 and Fig. 9As shown, for example, the outer cover body 121 is formed on both sides of the inner cover body 11 along its own thickness direction, and the outer cover body 121 completely covers the outer surface of the inner cover body 11.

[0113] The inner cover 11 and the outer cover 12 form a multi-layer structure, for example, Figure 7 and Fig. 9 In the illustrated embodiment, along the thickness direction of the upper cover 1 , the inner cover body 11 and the outer cover body 12 form a three-layer structure, and each layer of the structure is the outer cover body 121 , the inner cover body 11 and the outer cover body 121 in sequence.

[0114] The thickness of the material of each layer of the inner cover body 11 is 0.05 mm to 50 mm, and the thickness of the material of each layer of the outer cover body 12 is 0.05 mm to 50 mm.

[0115] Figure 5 and Figure 8 The structural schematic diagrams of the inner cover body 11 of some embodiments and other embodiments of the present application are respectively shown.

[0116] like Figure 3 , Figure 4 , Figure 5 and Figure 7 As shown, the upper cover 1 has a flange 15 formed by the inner cover body 11 and the outer cover body 12 , and no hole is provided at a position on the inner cover body 11 corresponding to the raised portion 14 of the upper cover 1 .

[0117] like Figure 3 , Figure 4 , Figure 8 and Fig. 9 As shown, the upper cover 1 has a flange 15 formed by the inner cover body 11 and the outer cover body 12. The inner cover body 11 has a plurality of first through holes 111 penetrating the inner cover body 11 in its thickness direction. The outer cover body 12 also includes a plurality of connecting parts 122 arranged corresponding to the plurality of first through holes 111. Each connecting part 122 passes through the corresponding first through hole 111 and is formed integrally with the outer cover body 121. The middle position of the upper cover 1 includes a raised portion 14 raised relative to the position of the flange 15, and the plurality of first through holes 111 are arranged on the raised portion 14 of the upper cover 1.

[0118] like Figure 3 , Figure 4 , Figure 8 and Fig. 9 As shown, each connection portion 122 fills the internal space of the corresponding first through hole 111 , and the base material of the inner cover body 11 is welded to the material of the connection portion 122 .

[0119] like Figure 3 and Figure 4 , Figure 7 and Fig. 9As shown, a connecting hole 13 is provided on the flange 15, and the connecting hole 13 passes through the inner cover body 11 and the outer cover body 12 along the thickness direction of the flange 15. The connecting hole 13 is configured to penetrate the connecting piece required to connect the upper cover 1 and the box shell 3 of the battery pack B.

[0120] like Figure 5 and Figure 8 As shown, the edge of the inner cover body 11 has a second through hole 131 that penetrates its thickness direction. The second through hole 131 constitutes a part of the connecting hole 13. The outer cover body 12 avoids the position of the second through hole 131 during the forming process to form the connecting hole 13.

[0121] like Figure 3 , Figure 4 , Figure 7 and Fig. 9 As shown, the outer cover body 12 further includes a plurality of reinforcing ribs 123 , which are disposed on the flange 15 and are integrally formed with the outer cover body 121 .

[0122] Each reinforcing rib 123 includes a first rib 1231 extending along the edge of the upper cover 1 and a second rib 1232 extending around the connecting hole 13 .

[0123] like Figure 3 , Figure 4 and Figure 6 As shown, the middle position of the upper cover 1 includes a raised portion 14 raised relative to the flange 15, and at least one reinforcing rib 123 includes a third rib 1233, one end of the third rib 1233 is connected to the raised portion 14, and the other end is connected to the first rib 1231 or the second rib 1232.

[0124] Along the length direction or width direction of the upper cover 1, from the side away from the raised portion of the upper cover 1 to the side close to the raised portion 14 of the upper cover 1, the first ribs 1231 of the plurality of reinforcing ribs 123 are arranged side by side and spaced apart. For example, the first ribs 1231 of three reinforcing ribs 123 are arranged side by side and spaced apart, wherein a reinforcing rib 123 located in the middle of the three reinforcing ribs 123 includes a second rib 1232, two first ribs 1231 located on both sides of the second rib 1232, and a third rib 1233 connected to the raised portion 14, a reinforcing rib 123 located on the side close to the raised portion 14 includes a first rib 1231 and a third rib 1233, and the third rib 1233 of the reinforcing rib 123 located in the middle and the third rib 1233 of the reinforcing rib 123 located on the side close to the raised portion 14 are arranged side by side and spaced apart.

[0125] According to the above description, the upper cover 1 of the battery pack B of this embodiment has at least one of the following advantages: The inner cover 11 is made of a composite material whose base material is a thermoplastic material. The composite material itself has high rigidity and can be used as the skeleton of the upper cover 1 to improve the rigidity of the upper cover 1, reduce the deformation of the upper cover 1 after molding, and make the upper cover 1 meet the requirements of the battery pack contour. In addition, the inner cover 11 made of composite material is conducive to the lightweight of the upper cover 1. The outer cover 12 is made of thermoplastic material, which can appropriately reduce the cost of the upper cover material compared to the upper cover made entirely of composite materials.

[0126] The material of the outer cover body 121 is welded to the base material of the inner cover body 11. At the connection position of the inner cover body 11 and the outer cover body 12, the inner cover body 11 and the outer cover body 12 can be integrally formed without producing an obvious interface, which is conducive to improving the bonding strength of the inner cover body 11 and the outer cover body 12. The self-strength and the strength after creep of this form of upper cover 1 are significantly higher than those of an upper cover made of a single material.

[0127] Because the inner cover body 11 can make the upper cover 1 have sufficient rigidity and reduce the thermal deformation of the upper cover 1, and no obvious boundary surface is generated between the inner cover body 11 and the outer cover body 12, the airtightness is good, which is beneficial to reduce the risk of air leakage from between the inner cover body 11 and the outer cover body 12, thereby improving the reliability of the thermal runaway protection measures.

[0128] The outer cover body 121 on one side of the inner cover body 11 along its own thickness direction faces the interior of the battery pack B. During thermal runaway of the battery pack B, the high-temperature and high-pressure gas first contacts the outer cover body 121. The outer cover body 121 made of thermoplastic material can expand rapidly at high temperature to form a foamed insulation layer, which helps to prevent heat from spreading rapidly to the surrounding area of ​​the battery pack B.

[0129] The material of the outer cover body 12 can not only form a welding area through the outer cover body main body 121 and the base material of the inner cover body 11, but also can enter and pass through the multiple first through holes 111 to form multiple connecting parts 122. After the connecting parts 122 are cooled and solidified, they can form a limiting connection structure similar to riveting, which is beneficial to improve the connection strength between the outer cover body 12 and the inner cover body 11.

[0130] As a part of the outer cover 12, the plurality of reinforcing ribs 123 are made of the same thermoplastic material as the outer cover body 121, and can be integrally formed with the outer cover body 121. Based on the usual plastic processing technology, such as injection molding, the processing of the reinforcing ribs 123 with complex shapes can be realized. Considering that the edge of the upper cover 1 is usually used as the locking surface of the upper cover 1, the plurality of reinforcing ribs 123 arranged on the edge of the upper cover 1 can improve the rigidity of the locking surface of the upper cover 1, and reduce the rigidity of the locking surface after the upper cover 1 is connected to the box shell 3 of the battery pack B, without the need to set an additional metal strip.

[0131] The manufacturing method of the upper cover 1 of the above embodiment of the present application includes: applying the material of the outer cover body 12 in a molten state to the surface of the inner cover body 11, and solidifying to form the outer cover body 12, so that the material of the outer cover body 121 is welded to the base material of the inner cover body 11.

[0132] The step of applying the material of the outer cover body 12 in a molten state to the surface of the inner cover body 11 includes: using the inner cover body 11 as a core mold of an injection mold of the outer cover body 12 , and then injecting into the inner cavity of the injection mold.

[0133] The specific steps of the method for manufacturing the upper cover 1 are as follows.

[0134] By compression molding, the composite sheet whose base material is a thermoplastic material is pressed into a composite inner cover body 11 of a desired shape.

[0135] The molded inner cover body 11 is placed in the cavity of the injection mold of the outer cover body 12, and the inner cover body 11 is placed in a set position, and the inner cover body 11 is used as a core mold of the injection mold.

[0136] The injection mold is closed, and thermoplastic material is injected into the inner cavity of the injection mold. Under the action of the molten thermoplastic material, the base material of the inner cover body 11 is also melted accordingly, and the material of the outer cover body 121 is welded to the base material of the inner cover body 11.

[0137] For the inner cover body 11 provided with the first through hole 111 , the molten thermoplastic material further enters the first through hole 111 and forms a connecting portion 122 integrally connected to the outer cover body 121 , and the material of the connecting portion 122 is welded to the base material of the inner cover body 11 .

[0138] For the outer cover 12 provided with the reinforcing rib 123, the shape of the area of ​​the inner cavity of the injection mold corresponding to the position of the reinforcing rib 123 is set to a shape adapted to the reinforcing rib 123. For the upper cover 1 provided with the connecting hole 13, the injection mold occupies the position of the connecting hole 13 in the mold closing state, so that the molten thermoplastic material avoids the connecting hole 13.

[0139] After the outer cover body 12 and the inner cover body 11 are cooled and shaped, the injection mold is opened and the upper cover 1 is ejected to obtain the molded upper cover 1.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or some technical features can be replaced by equivalents, which should all be included in the scope of the technical solution requested for protection in this application.

Claims

1. A top cover (1) of a battery pack (B), characterized in that: include: An inner cover (11) made of a composite material; and The outer cover body (12) comprises an outer cover body main body (121) formed outside the inner cover body (11), and the base material of the inner cover body (11) and the material of the outer cover body main body (121) are welded; The inner cover body (11) has a plurality of first through holes (111) extending through the inner cover body (111) in the thickness direction thereof, and the outer cover body (12) further comprises a plurality of connecting portions (122) arranged corresponding to the plurality of first through holes (111), each of the connecting portions (122) passing through the corresponding first through hole (111) and being formed integrally with the outer cover body (121).

2. The upper cover (1) according to claim 1, characterized in that: Each of the connecting portions (122) fills the internal space of the corresponding first through hole (111), and the base material of the inner cover body (11) is welded to the material of the connecting portion (122).

3. The upper cover (1) according to claim 1, characterized in that: The upper cover (1) has a flange (15) formed by the inner cover body (11) and the outer cover body (12), and the flange (15) is provided with a connecting hole (13). The connecting hole (13) penetrates the inner cover body (11) and the outer cover body (12) along the thickness direction of the flange (15), and the connecting hole (13) is configured to penetrate a connecting piece required to connect the upper cover (1) and the box shell (3) of the battery pack (B).

4. The upper cover (1) according to claim 3, characterized in that: The outer cover body (12) further comprises a plurality of reinforcing ribs (123), wherein the plurality of reinforcing ribs (123) are arranged on the flange (15) and are formed integrally with the outer cover body (121).

5. The upper cover (1) according to claim 4, characterized in that: Each of the reinforcing ribs (123) comprises a first rib (1231) extending along an edge of the flange (15) and / or a second rib (1232) extending around the connecting hole (13).

6. The upper cover (1) according to claim 5, characterized in that: The middle position of the upper cover (1) includes a raised portion (14) raised relative to the flange (15), and at least one of the reinforcing ribs (123) includes a third rib (1233), one end of the third rib (1233) is connected to the raised portion (14), and the other end is connected to the first rib (1231) or the second rib (1232).

7. The upper cover (1) according to any one of claims 1 to 6, characterized in that: The base material of the inner cover body (11) includes a thermoplastic material, and / or the material of the outer cover body (12) includes a thermoplastic material.

8. The upper cover (1) according to any one of claims 1 to 6, characterized in that: The base material of the inner cover body (11) and / or the material of the outer cover body (12) comprises at least one of the following materials: PP, PA, PBT; and / or The reinforcing material of the composite material comprises at least one of the following materials: glass fiber, carbon fiber, talcum powder; and / or The composite material further comprises a flame retardant material and / or a toughening material.

9. The upper cover (1) according to any one of claims 1 to 6, characterized in that: The base material of the inner cover body (11) and the material of the outer cover body (12) are the same material.

10. The upper cover (1) according to any one of claims 1 to 6, characterized in that: The outer cover body (121) is formed on one side or both sides of the inner cover body (11) along its own thickness direction.

11. The upper cover (1) according to claim 10, characterized in that: The outer cover body (121) completely covers the outer surface of the inner cover body (11).

12. The upper cover (1) according to any one of claims 1 to 6, characterized in that: The inner cover body (11) and the outer cover body (12) form a multi-layer structure, wherein the thickness of the material of each layer of the inner cover body (11) is 0.05 mm to 50 mm, and / or the thickness of the material of each layer of the outer cover body (12) is 0.05 mm to 50 mm.

13. A battery pack (B), characterized in that: include: Battery pack (2); Box shell (3); and The upper cover (1) according to any one of claims 1 to 12 is snap-fitted to the box shell (3), and the battery pack (2) is arranged in a space formed by the box shell (3) and the upper cover (1).

14. An electrical device (D), characterized in that: It comprises a battery pack (B) according to claim 13, wherein the battery pack (B) is used to provide power to the power-consuming device (D).

15. A method for manufacturing an upper cover (1) of a battery pack (B) according to any one of claims 1 to 12, characterized in that: include: The material of the outer cover body (12) is applied to the surface of the inner cover body (11) in a molten state and solidified to form the outer cover body (12), so that the material of the outer cover body main body (121) is welded to the base material of the inner cover body (11).

16. The method for manufacturing the upper cover (1) according to claim 15, characterized in that: The material of the outer cover body (12) is a thermoplastic material, and the process of applying the material of the outer cover body (12) in a molten state to the surface of the inner cover body (11) comprises: using the inner cover body (11) as a core mold of an injection mold for the outer cover body (12), and then injecting into the inner cavity of the injection mold.

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