WO2023116730A1 - Lower case body of battery case, battery case, battery pack, and electric automobile - Google Patents

Abstract

Provided in the present invention are a lower case body of a battery case, a battery case, a battery pack, and an electric automobile. The lower case body comprises an inner housing and an outer housing, which are arranged in a stacked manner, wherein a groove is formed in an edge of an upper end of the outer housing; a folded-edge extending into the groove is provided at an upper end of the inner housing; and the folded-edge and the groove are connected in a fitting manner. The battery case uses an inner housing and an outer housing structure, and compared with the condition that the inner housing is engaged, at an edge thereof, to the outer housing by means of connection between the folded-edge and the groove in a fitting manner, a reinforced connection between the inner housing and the outer housing is realized, such that the integrity of the inner housing and the outer housing is enhanced, and the strength of the lower case body is enhanced when the overall weight is controlled, thereby improving the overall strength of the lower case body.

Description

Lower box body of battery box, battery box, battery pack and electric vehicle

This application claims the priority of the Chinese patent application 202111567173.8 with the filing date on December 20, 2021 and the Chinese patent application 202111673238.7 with the filing date on December 31, 2021. This application cites the full text of the above-mentioned Chinese patent application.

technical field

The invention relates to a lower box body of a battery box, a battery box, a battery pack and an electric vehicle.

Background technique

Electric vehicles, which use battery packs placed in electric vehicles to provide electricity. A battery pack usually includes a battery box, a battery module and electrical components placed in the battery box. The battery box is used to isolate the battery module and electrical components from the external environment, and protect the battery module and electrical components from collisions.

At present, the battery boxes of electric vehicles on the market all use metal structure boxes. The metal structure has good thermal conductivity and poor thermal insulation performance. Usually, adding mica sheets is used to increase the thermal insulation performance, but this will increase the weight of the box. While ensuring the insulation performance of the battery box, the strength factor also needs to be considered. On the premise of not significantly increasing the weight of the box, how to ensure the thermal insulation performance of the battery box and meet the strength requirements is a difficult problem in the design of the battery box at present.

Contents of the invention

The technical problem to be solved by the present invention is to provide a lower box body of the battery box, a battery box, a battery pack and an electric vehicle in order to overcome the defect of poor heat preservation effect of the battery box in the prior art.

The present invention solves the above technical problems through the following technical solutions:

The invention provides a lower box body of a battery box, which has an accommodating chamber with an open upper end, and is used to combine with an upper box cover to form a battery box, and the lower box body includes an inner shell and an outer shell stacked on top of each other , the upper edge of the outer casing is provided with a groove, the upper end of the inner casing is provided with a flange extending into the groove, and the flange is mated and connected with the groove.

In this technical solution, the lower box of the battery box adopts an inner and outer shell structure, which can reduce heat conduction inside and outside the box and improve thermal insulation performance, and the inner and outer double-layer structure will also increase the strength of the lower box. The inner casing buckles the outer casing at the edge by using the flanging and groove matching connection to realize the strengthened connection between the inner and outer casings, enhance the integrity of the inner and outer casings, and enhance the strength of the lower box under the condition of controlling the overall weight , thereby improving the overall strength of the lower box.

Preferably, the flange covers at least a part of the inner surface of the groove along its extending direction, and fits closely with the inner surface of the groove.

In this technical solution, the flange and the inner surface of the groove are arranged in close contact, so that the two can be closely connected and the integrity of the connection between the two can be improved.

Preferably, the flange covers at least up to the inner bottom surface of the groove along its extending direction.

In this technical solution, when the flanging deformation causes it to have a tendency to fall out, since the flanging is provided with a bottom section covering the inner bottom surface of the groove, the bottom section can resist the deformation of the groove, further enhancing the binding between the flanging and the groove combined strength.

Preferably, the thickness of the bottom section of the flange covering the inner bottom surface of the groove is greater than the average thickness of the flange.

In this technical solution, when the flanging deformation causes it to have a tendency to fall out, the bottom section covering the inner bottom surface of the groove will be subject to a greater extrusion force; by increasing the thickness of the bottom section of the flanging, the resistance of the bottom section can be enhanced. Deformation ability further enhances the snapping strength between the flanging and the groove.

Preferably, the flange covers the entire inner surface of the groove in the extension direction, and continues to extend out of the groove to form a protruding part, the protruding part is located between the upper case cover and the The combination surface between the lower boxes, and the protruding part fits with the outer edge of the groove.

In this technical solution, when the flanging covers the inner bottom surface of the groove in the direction of extension, when the flanging produces a deformation tendency to come out of the groove, the bottom section covering the inner bottom surface of the groove can be deformed under the action of the deformation tendency. , stuck in the groove, to a large extent can avoid the flanging out; and the protruding part arranged on the combined surface between the upper box cover and the lower box body, when the upper box cover and the lower box body are combined with each other, The protruding part is sandwiched between the two, so that the inner shell can be pressed more tightly on the outer shell.

Preferably, the internal bottom surface of the groove is provided with internal groove reinforcement ribs at intervals along the length direction of the groove, and the bottom section covering the internal bottom surface of the groove is in contact with the internal groove reinforcement ribs.

In this technical solution, the strength of the outer casing at the groove is improved by setting the rib in the groove in the groove, and the groove of the outer casing is prevented from becoming a weak link in the strength of the lower box.

Preferably, the inner surface of the flange facing away from the groove transitions gently at the corners.

In the technical solution, through the above-mentioned structure, it is possible to avoid the stress concentration of the inner casing at the corners of the flanging.

Preferably, the groove is a sealing groove, and the sealing groove is used for accommodating a sealing strip that seals the upper case cover and the lower case body.

In this technical solution, when the groove is used as a sealing groove, the groove not only accommodates the flanging, but also accommodates the sealing strip; while the groove has the function of connecting the inner shell and the outer shell, it also has the function of sealing the upper box cover, the lower The function of the box body; the outer shell only needs to open a groove, and there is no need to open another sealing groove, which avoids the reduction of the strength of the outer shell caused by the additional groove of the outer shell.

Preferably, the thickness of the outer shell is not less than the thickness of the inner shell, the outer circumference of the outer shell extends outward to form a side reinforcement structure, and the groove is arranged on the side reinforcement structure end face.

In this technical solution, the overall thickness of the outer casing is guaranteed by setting the side wall reinforcement structure, so that the outer casing can be used as the main force-bearing part of the lower box body, and the strength of the lower box body can be guaranteed; the side wall reinforcement structure is also The setting of the groove provides space.

Preferably, the outer peripheral surface of the side wall reinforcement structure is provided with a plurality of recessed parts recessed toward the outer peripheral surface of the outer shell.

In the technical solution, by providing the recessed part, the overall weight of the battery box is reduced while ensuring the strength of the outer casing. In addition, lightweight thermal insulation materials can be placed in the recessed part to improve the thermal insulation performance of the lower box, and the connecting plate is covered and fixed on the side wall reinforcement structure to fix the quick change unit or battery pack fixing unit connected to the body, even if it is not placed Lightweight insulation material, the air in the recessed part can also play a certain insulation effect and improve the insulation performance of the lower box.

Preferably, the inner surface or the outer bottom surface of the outer shell is provided with reinforcing ribs at intervals or interlacedly.

In this technical solution, the overall strength of the battery box can be enhanced by arranging reinforcing ribs; especially, when the outer casing is made of non-metallic composite materials, the lack of strength of non-metallic composite materials can be effectively compensated by arranging reinforcing ribs question.

Preferably, the flange and the groove are also connected by bonding or welding.

In this technical solution, the connection strength between the inner casing and the outer casing can be further enhanced by connecting the flanging and the groove by bonding or welding.

Preferably, both the inner shell and the outer shell are made of non-metallic composite materials, and the non-metallic composite materials include fiber-reinforced resin-based composite materials.

In this technical solution, the inner and outer shells made of non-metallic composite materials are formed at one time, with high processing precision, good heat preservation, good flame retardancy, and high molding structure; the thermal insulation of composite materials can reduce The influence of ambient temperature on the temperature inside the battery box can effectively solve the occurrence of condensation in the battery box and effectively eliminate safety risks such as insulation failure caused by condensed water; the liner made of composite materials can also improve the corrosion resistance of the battery box performance, improve the service life of the battery box.

Preferably, the fiber-reinforced resin-based composite material includes glass fiber-reinforced resin-based composite material, and/or carbon fiber-reinforced resin-based composite material, and/or resin fiber-reinforced resin-based composite material, and/or ceramic fiber-reinforced resin-based composite material composite material.

In this technical solution, the above-mentioned fiber-reinforced resin-based composite materials are all excellent choices for manufacturing battery boxes.

The present invention also provides a battery box. The battery box includes an upper box cover and the above-mentioned lower box body. The upper box cover and the lower box body are combined with each other to seal the accommodating cavity.

In this technical solution, when the lower box body with inner and outer shell structures is combined with the upper box cover to form the battery box, not only the overall strength of the battery box is ensured, but also the sealing performance of the battery box is ensured. Especially when the battery box is made of non-metallic material, the structural design of the battery box can effectively compensate for the lack of strength of the non-metallic material.

The present invention also provides a battery pack, the battery pack includes a battery box and a battery unit arranged in the accommodating cavity, the battery unit includes an electric cell or a battery module formed by the electric cell, and the lower case A quick-change unit or a fixing unit is installed on the outer side of the body, the quick-change unit is used to realize the detachable connection of the battery pack to the electric vehicle; the fixed unit is used to realize the fixed connection of the battery pack to the electric vehicle .

In this technical solution, when the above-mentioned battery box is used to form a battery pack, the battery unit and electrical components are enclosed in the accommodating cavity surrounded by the upper box cover and the lower box body, forming a protective barrier for the battery unit and electrical components and having Heat preservation effect; quick change unit or fixed unit, used to realize the connection between the battery pack and the electric vehicle.

Among them, the quick change unit includes but is not limited to: electric/liquid cooling connector, locking mechanism, etc., and the locking mechanism includes a threaded locking mechanism (a locking mechanism that fixes the battery box and the vehicle body through multiple bolts), locking pins, etc. Locking mechanism (a locking mechanism that fixes the battery box to the vehicle body by locking pins), a rotation locking mechanism (a locking mechanism that fixes the battery box to the vehicle body by rotating and locking), and a flipping locking mechanism (The locking mechanism that fixes the battery box and the vehicle body by flipping and locking), the pressing locking mechanism (the locking mechanism that fixes the battery box and the vehicle body by pressing the locking method), the staggered tooth locking mechanism ( The locking mechanism that fixes the battery box and the vehicle body through the staggered locking method), the latch locking mechanism (the locking mechanism that fixes the battery box and the vehicle body through the latch locking method), the push-pull locking mechanism (the locking mechanism to fix the battery box and the vehicle body);

The fixing unit includes a bolt-type locking mechanism or other types of fixed connection mechanisms (including but not limited to mechanical, electrical or magnetic connections, etc.) and the like.

The present invention also provides an electric vehicle, including the above-mentioned battery pack.

By installing a suitable quick-change unit or battery pack fixing unit, the battery pack can be used for quick-change electric vehicles (the battery pack is detachably connected to the Body, with charging on the body as the main means of energy supplement), electric vehicles with quick change and charging functions and other types of electric vehicles.

In the technical solution, when the above-mentioned battery pack is applied to an electric vehicle, the sealing performance of the battery box can be guaranteed while ensuring the overall strength of the battery box. Especially when the battery box is made of non-metallic material, the structural design of the battery box can effectively compensate for the lack of strength of the non-metallic material.

On the basis of conforming to common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred examples of the present invention.

The positive progress effect of the present invention is:

The lower box of the above-mentioned battery box, the battery box, the battery pack and the electric vehicle, the battery box adopts the structure of the inner and outer shells, and the flange and the groove are used to cooperate and connect so that the inner shell buckles the outer shell at the edge to realize the gap between the inner and outer shells. Strengthen the connection, enhance the integrity of the inner and outer shells, and enhance the strength of the lower box while controlling the overall weight, thereby improving the overall strength of the lower box.

Description of drawings

FIG. 1 is a schematic structural diagram of a battery pack according to Embodiment 1 of the present invention.

FIG. 2 is a schematic structural view of the lower box body of the battery box shown in FIG. 1 .

FIG. 3 is a structural schematic diagram of battery modules and electrical components placed inside the battery box shown in FIG. 1 .

FIG. 4 is a schematic cross-sectional view of the battery box shown in FIG. 1 .

FIG. 5 is a top view of the groove of the outer casing shown in FIG. 1 .

Fig. 6 is a schematic cross-sectional view of the battery box according to the second embodiment of the present invention.

FIG. 7 is a schematic cross-sectional view of a battery box according to Embodiment 3 of the present invention.

Fig. 8 is a schematic structural view of the upper case cover of the battery case of the test example of the present invention.

Explanation of reference signs:

battery box 100; upper box cover 101; box cover shell 105; heat insulation layer 106; protective layer 107; lower box body 102; inner casing 1; Outer casing 2 ; groove 21 ; side wall reinforcement structure 22 ; recessed portion 23 ; reinforcement rib 24 in the groove; accommodating cavity 3 ; sealing strip 103 ; quick change unit 104 ; battery unit 200 ;

Detailed ways

The present invention is further illustrated below by means of examples, but the present invention is not limited to the scope of the examples.

Embodiment one

FIG. 1 shows a battery pack used in an electric vehicle. The battery pack includes a battery box 100 and a number of battery cells 200 and a number of electrical components 300 disposed in the battery box 100 . Wherein, the battery unit 200 is used for storing electricity, and the electrical component 300 is used for connecting the battery unit 200 and external components.

The battery box 100 includes an upper box cover 101 and a lower box body 102 . As shown in FIG. 2 and FIG. 3 , the lower case 102 includes an accommodating chamber 3 with an open upper end, and the accommodating chamber 3 is used to accommodate several battery units 200 and several electrical components 300 . The lower box body 102 is used to combine with the upper box cover 101 to form the battery box 100 .

As shown in Figure 4, the lower box body 102 includes an inner shell 1 and an outer shell 2 stacked on top of each other. The upper edge of the outer shell 2 is provided with a groove 21, and the upper end of the inner shell 1 is provided with a groove 21. The extended flanging 11, the flanging 11 is connected with the groove 21 in cooperation. The battery box 100 adopts an inner and outer shell structure, which can reduce the heat conduction inside and outside the box, improve the heat preservation performance, and the inner and outer two-layer structure will also increase the strength of the lower box; further use the flange 11 and the groove 21 to make the inner shell The body 1 clasps the outer shell 2 at the edge, realizes the strengthened connection between the inner and outer shells, enhances the integrity of the inner and outer shells, and enhances the strength of the lower box 102 while controlling the overall weight, so as to improve the strength of the lower box 102 overall strength.

The larger the area of the flange 11 covering the inner surface of the groove 21 in the extension direction, the more the connection strength between the inner shell 1 and the outer shell 2 can be increased, thereby reducing the deformation of the flange 11 from the groove 21. 21, enhance the bonding strength at the edges of the inner shell 1 and the outer shell 2.

In this embodiment, the flange 11 covers the entire inner surface of the groove 21 in the extension direction, and continues to extend outward of the groove 21 to form the protruding portion 111 . The protruding portion 111 is located on the combined surface between the upper case cover 101 and the lower case body 102 , and the protruding portion 111 is attached to the outer edge of the groove 21 .

Wherein, the flange 11 covers the entire inner surface of the groove 21 in the extension direction, so that the flange 11 can be firmly embedded in the groove 21 . When the flange 11 covers the inner bottom surface of the groove 21 in the extension direction, when the flange 11 produces a deformation tendency to escape from the groove 21, the bottom section 112 covering the inner bottom surface of the groove 21 can be deformed under the action of the deformation tendency. , stuck in the groove 21, to a large extent can prevent the flanging 11 from coming out. Adhesively arranging the flange 11 and the inner surface of the groove 21 can make the two closely connected and improve the connection integrity of the two.

And, the protruding part 111 that is arranged on the combined surface between the upper case cover 101 and the lower case body 102, when the upper case cover 101 and the lower case body 102 are combined with each other, the protruding part 111 is sandwiched between the two. space, so that the inner shell 1 can be pressed more tightly on the outer shell 2.

As shown in FIG. 4 , the thickness of the bottom section 112 of the flange 11 covering the inner bottom surface of the groove 21 is greater than the average thickness of the flange 11 . When the flange 11 is deformed so that it has a tendency to fall out, the bottom section 112 covering the inner bottom surface of the groove 21 will be subject to a greater extrusion force; by increasing the thickness of the bottom section 112 of the flange 11, the resistance of the bottom section 112 can be enhanced. The deformability further enhances the engagement strength between the flange 11 and the groove 21 .

As shown in FIG. 5 , the internal bottom surface of the groove 21 is provided with internal reinforcement ribs 24 at intervals along the length direction of the groove 21 , and the bottom section 112 covering the internal bottom surface of the groove 21 abuts against the internal reinforcement ribs 24 . By arranging the ribs 24 in the groove 21 , the strength of the outer casing 2 at the groove 21 is improved, and the groove 21 of the outer casing 2 is prevented from becoming a weak link in the strength of the lower box body 102 .

In this embodiment, the inner surface 113 of the flange 11 facing away from the groove 21 has a gentle transition at the corner. Through the above structure, stress concentration at the corners of the flange 11 of the inner casing 1 can be avoided.

In this embodiment, the groove 21 can be used as a sealing groove for accommodating the sealing strip 103 that seals the upper case cover 101 and the lower case body 102 . When the groove 21 is used as a sealing groove, the groove 21 not only accommodates the flange 11, but also accommodates the sealing strip 103; while the groove 21 has the function of connecting the inner shell 1 and the outer shell 2, it also has the function of sealing the upper case cover 101 , The function of the lower casing 102. The outer casing 2 only needs to open a groove 21, and no additional sealing groove is required, which avoids the reduction of the strength of the outer casing 2 caused by additional grooves in the outer casing 2; and because the flange 11 of the inner casing 1 extends to the concave In the groove 21, the sealing strip 103 can fit the groove 21 in a large area, and can better seal the upper box cover 101 and the lower box body 102.

When the flange 11 continues to extend to form the protruding part 111, the sealing strip 103 can be arranged between the protruding part 111 and the outer casing 2, which further enhances the sealing effect of the battery box. In addition, when the groove 21 is used as a sealing groove at the same time, the inner surface 113 of the flange 11 away from the groove 21 transitions gently at the corner, which can improve the contact situation at the corner when the flange 11 contacts with the sealing strip 103, Improves sealing effect.

As shown in Figure 4, the thickness of the outer shell 2 is not less than the thickness of the inner shell 1, and the outer circumference of the outer shell 2 extends outward to form a side reinforcement structure 22, and the groove 21 is arranged on the side reinforcement structure 22. end face. By arranging the side wall strengthening structure 22, the overall thickness of the outer casing 2 is guaranteed, so that the outer casing 2 can be used as the main force-bearing part of the lower box body 102, and the strength of the lower box body 102 can be guaranteed; the side wall strengthening structure 22 is also The arrangement of the groove 21 provides space.

Wherein, the outer peripheral surface of the side reinforcement structure 22 is provided with a plurality of recessed portions 23 that are recessed toward the outer peripheral surface of the outer casing 2 . By providing the recessed portion 23, while ensuring the strength of the outer casing 2, the overall weight of the battery box is also reduced. In addition, lightweight thermal insulation materials can be placed in the recessed part 23 to improve the thermal insulation performance of the lower box body, and the connecting plate is covered and fixed on the side wall reinforcement structure 22 to fix the quick-change unit or the fixed unit connected to the electric vehicle. The air in the recessed portion 23 can also have a certain heat-insulation effect without placing light-weight heat-insulation materials, improving the heat-insulation performance of the lower box body.

Wherein, the inner surface and the outer bottom surface of the outer casing 2 may also be provided with reinforcing ribs. Ribs can be arranged at intervals or staggered. The overall strength of the battery box can be enhanced by providing reinforcing ribs. In particular, when the outer casing 2 is made of non-metallic composite material, the problem of insufficient strength of the non-metallic composite material can be effectively compensated by providing reinforcing ribs. Preferably, on the inner surface of the outer casing 2 (the surface facing the inner casing 1), vertically and horizontally intersecting ribs are formed, and the reinforcing ribs are bonded or welded to the inner casing, and the reinforcing ribs connect the outer casing to the inner casing. The inner casing is divided into several chambers to form a chamber structure, and light heat insulating materials can also be placed in the chamber structure to improve the heat insulation performance of the lower box body. A chamber structure is also formed between the outer shell and the inner shell to improve the heat insulation effect of the lower box. At the same time, the lower box is made of non-metallic composite material, which is further improved compared with the metal shell. Enhanced insulation performance, and the density of non-metallic composite materials is lower than that of metal materials. Compared with the lower box made of metal materials, the lower box made of non-metallic composite material of the present application has better thermal insulation performance and is lighter than the box made of metal when meeting the strength requirements of the battery box. The production process is simpler and the economic benefits are improved. .

In this embodiment, the flange 11 and the groove 21 may be connected by bonding or welding. Connecting the flange 11 and the groove 21 by bonding or welding can further enhance the connection strength between the inner casing 1 and the outer casing 2 .

In this embodiment, both the inner casing 1 and the outer casing 2 can be made of non-metallic composite materials, such as fiber-reinforced resin-based composite materials. However, the fiber-reinforced resin-based composite material may be one or more of glass fiber-reinforced resin-based composite materials, carbon fiber-reinforced resin-based composite materials, resin fiber-reinforced resin-based composite materials, and ceramic fiber-reinforced resin-based composite materials. The material of the lower box can also be other polymer composite materials with light weight, certain strength and high temperature performance, preferably the polymer composite material is a fiber-reinforced resin-based composite material. Among them, it is a better choice to use SMC composite material as the material of the inner casing 1 and the outer casing 2 .

The inner shell 1 and the outer shell 2 are made of non-metallic composite materials, one-time molding, high processing precision, good heat preservation, good flame retardancy, and high molding structure; the thermal insulation of the composite material can reduce the impact of the ambient temperature on the battery The influence of the temperature inside the box can effectively solve the occurrence of condensation in the battery box and effectively eliminate safety risks such as insulation failure caused by condensed water; the lower box made of composite materials can also improve the corrosion resistance of the battery box and improve The service life of the battery box.

The battery pack is formed after the battery unit 200 and the electrical components 300 are put into the battery box. The battery unit 200 can be a battery cell or a battery module formed by the battery cell. A quick-change unit 104 is installed on the outer surface of the lower box 102, and the quick-change unit 104 is used to realize the detachable connection of the battery pack relative to the electric vehicle. Wherein, the quick-change unit 104 includes necessary components such as a locking mechanism and an electrical/liquid cooling connector to meet quick-change of the battery pack. The quick-change unit includes but is not limited to: electric/liquid cooling connectors, locking mechanisms, etc., and the locking mechanisms include threaded locking mechanisms (a locking mechanism that fixes the battery box to the vehicle body through multiple bolts), locking pins Mechanism (the locking mechanism that fixes the battery box and the vehicle body by locking the lock pin), the rotation locking mechanism (the locking mechanism that fixes the battery box and the vehicle body by The locking mechanism that fixes the battery box and the vehicle body by turning over the locking method), the top-pressing locking mechanism (the locking mechanism that fixes the battery box and the vehicle body by pressing the Tooth locking mechanism to fix the battery box and the vehicle body), latch locking mechanism (the locking mechanism that fixes the battery box and the vehicle body by the latch locking method), push-pull locking mechanism (the A locking mechanism that fixes the battery box to the vehicle body).

When the above-mentioned battery box is used to form a battery pack, the battery unit 200 and the electrical component 300 are enclosed in the accommodating chamber 3 surrounded by the upper case cover 101 and the lower case body 102 to form a protective barrier for the battery unit 200 and the electrical component 300 and It has thermal insulation effect. Moreover, the lower box body 102 of the battery box is made of non-metal composite material, which can reduce the weight compared with the metal shell, and further improve the heat preservation effect and economic benefits.

In other embodiments, the quick change unit 104 can be replaced with a fixed unit, and the fixed unit is used to realize the fixed connection between the battery pack and the electric vehicle. The fixing unit may be a bolt-type locking mechanism or other types of fixed connection mechanism (including but not limited to mechanical, electrical or magnetic connection, etc.).

By installing a suitable quick-change unit or battery pack fixing unit, the battery pack can be used for quick-change electric vehicles (the battery pack is detachably connected to the Body, with charging on the body as the main means of energy supplement), electric vehicles with quick change and charging functions and other types of electric vehicles.

When the above-mentioned battery pack is applied to an electric vehicle, while ensuring the overall strength of the battery box, the airtightness of the battery box can also be ensured. Especially when the battery box is made of non-metallic composite material, the structural design of the battery box can effectively compensate for the lack of strength of the non-metallic material.

Embodiment two

Most of the structure of this embodiment is the same as that of Embodiment 1, the difference lies in the coverage area of the flange 11 in the groove 21 .

As shown in FIG. 6 , in this embodiment, the flange 11 covers one side of the inner surface of the groove 21 in the extending direction thereof. The flange 11 only covers one side of the inner surface of the groove 21 to realize the function of the inner shell 1 buckling the outer shell 2 at the edge. The flanging 11 with a shorter extension length is less difficult to process. When the groove 21 is a sealing groove, because the flange 11 only covers the inner surface of one side of the groove 21, a part of the sealing strip 103 is sealed with the flange 11, and the other part is also sealed with the outer shell 2, so that the outside world can be realized. and the sealing of the inner space of the accommodating cavity 3; at the same time, the sealing of the space between the outside world and the inner and outer shells can also be realized. In the case of a chamber structure between the inner shell 1 and the outer shell 2, the chamber Structural sealing can improve the thermal insulation performance of the lower box.

Embodiment three

Most of the structure of this embodiment is the same as that of Embodiment 1, the difference lies in the coverage area of the flange 11 in the groove 21 .

As shown in FIG. 7 , in this embodiment, the flange 11 not only covers the sides of the groove 21 in its extending direction, but also covers the inner bottom surface of the groove 21 . That is, the flange 11 has a bottom section 112 covering the inner bottom surface of the groove 21 . When the deformation of the flange 11 causes it to have a tendency to fall out, since the flange 11 is provided with a bottom section 112 covering the inner bottom surface of the groove 21, the bottom section 112 can resist the deformation of the groove 21, further strengthening the relationship between the flange 11 and the groove 21. of snapping strength.

Test case

A quick-change electric vehicle currently uses sheet metal battery packs (using mica sheets as insulation materials), and its weight is 371.5kg. Non-metallic composite battery packs with the same dimensions (external dimensions and internal space dimensions of the battery box) were prepared according to Example 1.

Utilizing the non-metallic composite lower box body in Embodiment 1, the inner side of the outer shell is provided with criss-cross reinforcing ribs, and the reinforcing ribs separate the outer shell 2 and the inner shell 1 into several chambers to form chambers structure. The height of the chamber structure between the outer shell 2 and the inner shell 1 (that is, the distance between the opposite surfaces of the outer shell 2 and the inner shell 1) is 5mm, and when no airgel is placed in the chamber structure, a The lower box is recorded as the lower box A of non-metallic composite material, the lower box formed when the airgel is placed in the chamber structure is recorded as the lower box B of non-metallic composite material, the lower box A of non-metallic composite material and The lower box body B of the non-metallic composite material is combined with the upper box cover in a buckle-fitting manner to form a battery box of non-metallic composite material, which are denoted as battery box A of non-metallic composite material and battery box B of non-metallic composite material, respectively. After loading the battery module and necessary electrical components, a non-metallic composite battery pack A and a non-metallic composite battery pack B are formed. See Figure 1.

As shown in Figure 8, the above-mentioned upper box cover 101 of non-metallic composite material for forming a non-metallic composite material battery box with the lower box body A of the non-metallic composite material and the lower box body B of the non-metallic composite material respectively includes a box cover shell 105 , a thermal insulation layer 106 and a protective layer 107 . The insulation layer 106 and the protective layer 107 are sequentially covered and fixed on the side of the box cover shell 105 facing the lower box body 102. The material of the box cover shell 105 is SMC, and the material of the heat insulation layer 106 is an airgel felt with a thickness of 5 mm to protect The material of the layer 107 is fireproof cloth, and the way between the cover shell 105 and the heat insulation layer 106 and between the heat insulation layer 106 and the protective layer 107 is connected by structural adhesive bonding, and the cover shell 105 is provided with concave and convex Structure for added strength.

The upper box cover 101 and the lower box body 102 are sealed by a U-shaped seal, and the side of the upper box cover 101 is provided with a concave portion, which cooperates with the raised portion arranged on the lower box body 102 side to form a snap connection ( The structure of snap connection and U-shaped seal is shown in Fig. 1 and Fig. 4), and the upper box cover 101 and the lower box body 102 are molded once to realize the fastening of the snap connection structure.

Test the non-metallic composite material battery pack A, non-metallic composite material battery pack B and sheet metal battery pack of the same size and specification.

In terms of weight test, the mass of the non-metallic composite lower box B is 45kg, while the sheet metal lower box (using mica sheet as insulation material) of the same size and specification has a mass of 60.4kg. Compared with the lower box made of sheet metal, the lower box B made of non-metallic composite material has a weight reduction of 25.5%. The weight of the battery box B made of non-metallic composite material is 57.8kg, and the weight of the battery box made of sheet metal is 70.772kg. The weight advantage of the battery box made of non-metallic composite material is obvious. Compared with the lower box B of non-metallic composite material, the lower box A of non-metallic composite material lacks the airgel felt placed in the chamber structure. Due to the lower density of the airgel felt, the amount of use is not large , therefore, the quality of the non-metallic composite lower box A is equivalent to that of the non-metallic composite lower box B, with a slight decrease (almost negligible). In terms of the overall weight of the battery pack, the overall weight of the non-metallic composite battery pack A and the non-metallic composite battery pack B is 2-3% less than that of the sheet metal battery pack, and the weight advantage is obvious.

In terms of strength testing, the non-metallic composite material lower box A and the non-metallic composite material lower box B, and the non-metallic composite material upper cover used to form a composite non-metallic battery box with the two all meet GB/T 31467.3- 2015 "Lithium-ion Traction Battery Packs and Systems for Electric Vehicles Part 3: Safety Requirements and Test Methods" stipulates the strength and other requirements (the actual test can reach 1.5 times the standard). Can be used in electric vehicles.

In terms of thermal insulation performance and heat insulation performance: the initial temperature in the package is 20-30°C, and it is placed in an environment of 7-9°C for 600 minutes, the accumulative temperature change rate of the cells in the pack of non-metallic composite battery pack A (The accumulative cooling rate) is lower than 50% of the battery pack made of sheet metal (the temperature of the single cell is measured by optical fiber), and the accumulative temperature change rate of the single cell in the non-metallic composite battery pack B is only the sheet metal battery pack. About 40% of the battery pack is made of gold material. This advantage is more obvious at lower temperatures, and it can ensure that the temperature of the battery core is at a better operating temperature when used in cold northern regions. Moreover, after testing, the non-metallic composite material battery pack A and the non-metallic composite material battery pack B can withstand a high temperature of 1000°C. In the test of simulating a battery fire, even if the battery is completely burned, the non-metallic composite material box is basically in the whole test process. In good condition with only smoke and no open flames.

The cell placement cavity of non-metallic composite battery pack A and non-metallic composite battery pack B is filled with thermally conductive glue (the filling height of thermally conductive glue is about 1/3 of the height of the battery), so as to increase the temperature uniformity between the cells , to avoid thermal runaway caused by abnormal temperature of individual cells. Secondly, the battery cells (or battery modules formed by the battery cells) inside the battery box are formed as a whole, which increases the overall strength of the battery pack. Comparing the non-metallic composite battery pack B in the above case with the above-mentioned sheet metal battery pack, in the same environment, when charging with a charging current of 40A (SOC from 0-100%), the sheet metal battery pack is faster than the non-metallic battery pack. The accumulative temperature rise of metal composite battery pack B is more than 5°C, the charging capacity of non-metallic composite battery pack B is more than 5% higher than that of sheet metal battery packs, and the maximum temperature difference inside the box of composite non-metallic battery packs ( Obtained by recording all positive and negative lug temperatures) Uniformity maintained at 1.5-2°C. This is not only related to the use of thermally conductive adhesive, but also related to the specific heat capacity and thermal insulation performance of SMC higher than that of sheet metal materials. The above factors make the non-metallic composite battery pack of this application more advantageous than sheet metal battery packs in terms of avoiding thermal runaway .

The performance of some raw materials used in the above-mentioned test examples is as follows:

SMC meets the following performance requirements: material grade (disordered glass fiber state) tensile strength ≥ 70Mpa (GB/T 1447-2005), bending strength ≥ 160MPa (GB/T 1449-2005), impact toughness ≥ 55KJ/m2 (GB /T 1451-2005), elongation at break ≥ 1.3% (GB/T 1447-2005).

The airgel felt has a density of about 0.16 mg/cm ³ .

Structural adhesive shear strength (anodized aluminum - anodized aluminum) ≥ 6MPa, tensile strength ≥ 5MPa, flame retardant grade V0.

The above-mentioned SMC, airgel felt and structural glue can be commercially available products or self-made products that meet the above performance requirements, and the rest of the materials are commercially available products.

Although the specific implementation of the present invention has been described above, those skilled in the art should understand that this is only an illustration, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims (17)

1. A lower box body of a battery box, which has an accommodating chamber with an open upper end, and is used to combine with an upper box cover to form a battery box, wherein the lower box body includes an inner shell and an outer shell stacked on top of each other The upper edge of the outer shell is provided with a groove, and the upper end of the inner shell is provided with a flange extending into the groove, and the flange is mated and connected with the groove.
2. The lower box body of the battery box according to claim 1, wherein the flange covers at least a part of the inner surface of the groove in the extending direction thereof, and is attached to the inner surface of the groove.
3. The lower box body of the battery box according to claim 2, wherein the flange covers at least to the inner bottom surface of the groove in the extending direction thereof.
4. The lower box body of the battery box according to claim 3, wherein the thickness of the bottom section of the flange covering the inner bottom surface of the groove is greater than the average thickness of the flange.
5. The lower box body of the battery box according to any one of claims 2-4, wherein the flange covers the entire inner surface of the groove in the extension direction, and continues to extend outward of the groove Extending to form a protruding part, the protruding part is located on the combined surface between the upper case cover and the lower case body, and the protruding part is attached to the outer edge of the groove.
6. The lower box body of the battery box according to any one of claims 3-5, wherein the internal bottom surface of the groove is provided with reinforcement ribs in the groove at intervals along the length direction of the groove, covering the groove. The bottom section of the inner bottom surface of the groove abuts against the reinforcing rib in the groove.
7. The lower box body of the battery box according to any one of claims 1-6, characterized in that, the inner surface of the flange facing away from the groove has a gentle transition at the corner.
8. The lower box body of the battery box according to any one of claims 1-7, wherein the groove is a sealing groove, and the sealing groove is used to accommodate the connection between the upper box cover and the lower box. body seal seal.
9. The lower box body of the battery box according to any one of claims 1-8, wherein the thickness of the outer casing is not less than the thickness of the inner casing, and the outer peripheral surface of the outer casing extends outward A side wall reinforcement structure is formed, and the groove is arranged on an upper end surface of the side wall reinforcement structure.
10. The lower box body of the battery box according to claim 9, wherein the outer peripheral surface of the side wall reinforcement structure is provided with a plurality of recessed parts that are recessed toward the outer peripheral surface of the outer casing.
11. The lower box body of the battery box according to claim 9 or 10, characterized in that, the inner surface or the outer bottom surface of the outer shell is provided with reinforcing ribs at intervals or interlacedly.
12. The lower box body of the battery box according to any one of claims 1-11, characterized in that, the flange and the groove are also connected by bonding or welding.
13. The lower box body of the battery box according to any one of claims 1-12, characterized in that, both the inner shell and the outer shell are made of non-metallic composite materials, and the non-metallic composite materials include Fiber reinforced resin matrix composites.
14. The lower box body of the battery box according to claim 13, wherein the fiber-reinforced resin-based composite material comprises glass fiber-reinforced resin-based composite material, and/or carbon fiber-reinforced resin-based composite material, and/or resin fiber Reinforced resin-based composite materials, and/or ceramic fiber-reinforced resin-based composite materials.
15. A battery box, characterized in that the battery box includes an upper box cover and a lower box body according to any one of claims 1-14, the upper box cover and the lower box body are combined with each other, and the The accommodating cavity is closed.
16. A battery pack, characterized in that the battery pack comprises the battery box as claimed in claim 15 and a battery unit disposed in the accommodating cavity, the battery unit comprising an electric cell or a battery formed by an electric cell module, the outer side of the lower box is equipped with a quick-change unit or a fixed unit, the quick-change unit is used to realize the detachable connection of the battery pack to the electric vehicle; the fixed unit is used to realize the detachable connection of the battery pack The package is fixedly connected to the electric vehicle.
17. An electric vehicle, characterized by comprising the battery pack according to claim 16.

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