Battery pack box assembly and battery pack assembly containing the same

Abstract

The present invention provides a battery pack box assembly and a battery pack assembly including the same. The battery pack box assembly includes a first box, a second box, and a seal. The first box and the second box are arranged in combination. A sealing groove is provided on the first box. A protrusion is provided on the second box corresponding to the depression of the sealing groove. The protrusion is consistent with the extension direction of the sealing groove. The seal includes an abutment portion arranged in the sealing groove. The surface of the abutment portion facing the protrusion is provided with a receiving portion. The receiving portion receives and contacts the protrusion. Sealing is performed by combining the sealing groove of the box, the seal arranged in the sealing groove, and the protrusion on the second box, so that the sealing performance can be effectively improved. Among them, the abutment portion of the seal is arranged in the sealing groove, and the abutment portion is provided on the abutment portion to cooperate with the protrusion on the second box, so that the seal forms a sealing surface with a larger area in the sealing groove at least at the end and both sides of the protrusion.

Description

[0001] This application claims the priority of Chinese patent application No. 202111567173.8, filed on December 20, 2021. This application cites the entire text of the above Chinese patent application. Technical Field

[0002] The present invention relates to the technical field of electric vehicles, and in particular to a box assembly of a battery pack and a battery pack assembly comprising the box assembly. Background Art

[0003] Electric vehicles have the advantages of zero emissions, low noise, high cost-effectiveness in operation and maintenance, and are becoming more and more popular among users. The energy used by electric vehicles is the electricity provided by the battery packs on board. Electric vehicles need to be charged after the electricity is used up. The battery packs of electric vehicles are generally divided into fixed and replaceable types. Among them, fixed battery packs are generally fixed on the vehicle, and the vehicle is directly used as the charging object when charging. The replaceable battery packs are generally fixed on the bracket of the vehicle through a movable installation method. The battery pack can be removed for replacement or charging operations separately. After the replaced battery pack is charged, it is installed on the vehicle.

[0004] The battery box is the shell of the battery pack, which is used to accommodate and protect the battery cells and related electrical components, and to shield the water mist, air, and debris in the external environment from possible damage to the battery pack performance. In order to facilitate the placement of battery cells and related electrical components into the battery box, electric vehicles on the market currently use metal battery boxes, and the mainstream battery box structure is a combination of an upper box cover and a lower box body. Usually, the battery cells and related electrical components are arranged in the lower box body first, and then a flat sealing strip is placed on the combined surface of the upper box cover and the lower box body, and tightened with bolts and nuts. While sealing, the upper box cover and the lower box body are tightly connected to form a battery box.

[0005] However, in order to achieve a satisfactory sealing effect, the planar sealing strip needs to have a larger width, which will occupy a larger lateral area and have an adverse effect on the layout of the entire battery pack.

[0006] In addition, when the bolts are fastened to the upper box cover and the lower box body, they will also pass through the flat sealing strip, which will affect the sealing performance of the flat sealing strip. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the defect of poor sealing effect of the box at the joint in the prior art, and to provide a box assembly of a battery pack and a battery pack assembly containing the same.

[0008] The present invention solves the above technical problems through the following technical solutions:

[0009] A box assembly of a battery pack, the box assembly of the battery pack comprising:

[0010] A first box body and a second box body, wherein the first box body and the second box body are combined and arranged, the first box body is provided with a sealing groove, and the second box body is provided with a protrusion corresponding to the depression of the sealing groove, and the protrusion is consistent with the extending direction of the sealing groove;

[0011] The sealing member comprises an abutting portion arranged in the sealing groove, a surface of the abutting portion facing the protrusion is provided with an accommodating portion, and the accommodating portion accommodates and contacts the protrusion.

[0012] In the present technical solution, sealing is performed by combining the sealing groove of the box, the sealing member arranged in the sealing groove and the protrusion on the second box, which can effectively improve the sealing performance. Among them, the abutting portion of the sealing member is arranged in the sealing groove, and the abutting portion cooperates with the protrusion on the second box by setting a receiving portion, so that the sealing member forms a sealing surface with a larger area in the sealing groove at least at the end and both sides of the protrusion, thereby improving the sealing effect of the first box relative to the second box. In addition, while achieving a larger area of ​​sealing, the structure occupies a smaller box cross-sectional width, which saves space for the battery box in the width direction, is conducive to reducing the volume of the battery pack, and improves the energy density of the battery pack under the same battery pack volume.

[0013] Preferably, the sealing member further comprises a protruding portion, at least one side edge of the abutting portion extends outward to form the protruding portion, and the protruding portion is sandwiched between the first box body and the second box body.

[0014] In the technical solution, the protruding portion formed by the outward extension of at least one side edge of the abutting portion forms a second seal between the first box body and the second box body, thereby enhancing the sealing performance of the box body assembly.

[0015] Preferably, the protruding portion is located on an outward side of a combination of the first box body and the second box body relative to the abutting portion.

[0016] In the technical solution, the extended portion of the seal is relatively arranged outside the abutting portion, so as to improve the sealing effect of the seal on the combination of the first box body and the second box body at the outer joint, so as to prevent water, air, dust, etc. from the external environment from entering the joint between the first box body and the second box body. In addition, the sealing surface formed between the extended portion and the box body first faces the water, air, dust, etc. from the external environment, so as to block foreign substances.

[0017] Preferably, there is a height difference between the edges on both sides of the abutting portion of the seal.

[0018] In this technical solution, by providing a drop at both ends of the seal, when the seal is clamped between the first box and the second box, the two ends of the seal have different deformation amounts. This asymmetrical deformation distribution improves the tightness of the seal with the first box and the second box. The sealing groove is set high outside and low inside, so that the insulation material of the upper cover can extend to the inside of the protrusion, thereby improving the insulation effect. A protruding portion is provided on the outside of the seal to improve the sealing performance.

[0019] Preferably, the first box is a lower box, and the second box is an upper box;

[0020] The protruding portion is higher than the abutting portion,

[0021] And / or, the protruding portion is higher than an outer seam formed by the combination of the first box body and the second box body.

[0022] In the present technical solution, by setting the relatively outer protruding portion of the seal at a high position, and setting the protruding portion at a position higher than the external joint between the first box body and the second box body, it is difficult for external liquids such as rainwater to penetrate into the position of the seal through the external joint between the first box body and the second box body under the action of gravity, thereby improving the sealing performance against external liquids.

[0023] Preferably, the edge of the second box body is provided with a flange, and the flange extends toward the peripheral side of the first box body in a direction away from the second box body.

[0024] In this technical solution, the outer edge of the second box body has a downward flange, which can play a role in squeezing the seal from the outside in the horizontal direction together with the protrusion on the second box body, making the sealing of the box body more reliable and preventing rainwater from flowing into the box body assembly.

[0025] Preferably, an outward side of the protruding portion abuts against the flange surface.

[0026] In the present technical solution, a sealing surface is added by making the protruding part abut against the flange on the outward side, and the flange located on the outside of the second box body and the protrusion located on the inside of the second box body cooperate to squeeze the seal: the protruding part of the seal can be squeezed from both sides in the horizontal direction to reliably compress the protruding part and prevent the protruding part from extending outward again when the first box body and the second box body are clamped, thereby reducing the sealing effect.

[0027] Preferably, a surface of the sealing member facing the sealing groove is provided with a plurality of protrusions.

[0028] In the technical solution, the degree of compression between the sealing member at the protruding portion and the sealing groove is increased, thereby improving the sealing effect.

[0029] Preferably, the protrusion comprises:

[0030] a first sealing surface, the first sealing surface is arranged toward the sealing groove, and an angle formed between the first sealing surface and the surface of the sealing member is an obtuse angle,

[0031] The second sealing surface is arranged in a direction opposite to the sealing groove, the first sealing surface is adjacent to the second sealing surface, and the angle formed by the second sealing surface and the surface of the sealing element is a right angle or an acute angle.

[0032] In the technical solution, through the above-mentioned structural setting, when the seal is installed into the sealing groove, the resistance caused by the protrusion to the installation of the seal is reduced. At the same time, when the seal is removed from the sealing groove, the resistance caused by the protrusion to the removal of the seal is increased.

[0033] Preferably, the protrusion is wedge-shaped on the surface of the sealing element.

[0034] In this technical solution, the sealing performance is increased to prevent the sealing member from being separated from the relative protrusion.

[0035] Preferably, along the direction from the second box body to the first box body, the two side surfaces of the protrusion gradually approach each other, and the two side surfaces of the protrusion fit with the accommodating portion.

[0036] In the technical solution, both sides of the protrusion are in contact with the sealing member through inclined surfaces, thereby improving the sealing effect.

[0037] Preferably, the first box body is a lower box body, the second box body is an upper box body, the first box body and the second box body are both made of polymer composite materials, the first box body includes a first outer box shell located on the outside and a first inner box shell located on the inside, and the seal is at least sandwiched between the first outer box shell and the second box body.

[0038] In the technical solution, the first box body, as the lower box body, has relatively large load-bearing requirements and self-strength requirements. Therefore, by adopting a box body made of composite materials formed by combining inner and outer box shells, the first box body has the advantages of high self-strength and good heat insulation effect. By setting the seal between the first outer box shell and the second box body, the sealing of this place is achieved, and the influence of the external ambient temperature on the first inner box shell of the first box body is reduced. The first outer box shell can abut the side of the seal to increase the deformation of the seal, thereby enhancing the sealing effect. The first outer box shell can abut the protruding part of the seal to increase the abutment surface between the first outer box shell and the seal, thereby enhancing the sealing effect. The depression on the first outer box shell cooperates with the protrusion on the seal to increase the connection between the first outer box shell and the first box body, thereby enhancing the sealing effect.

[0039] Preferably, the second box body comprises a second outer box shell located on the outside and a second inner box shell located on the inside, and the second inner box shell is arranged on a side surface of the second outer box shell facing the first box body.

[0040] In the present technical solution, the second box body as the upper box body also adopts the combination of inner and outer box shells, which can increase the structural strength and reduce the influence of the external ambient temperature on the box assembly of the battery pack.

[0041] Preferably, the second inner box shell comprises an aerogel felt and a protective layer;

[0042] The surface of the first box body located inside the sealing groove abuts against the second inner box shell.

[0043] In this technical solution, a lightweight flexible insulation layer and a protective layer form an insulation layer, which has a certain softness and can be compressed a small amount, so that the insulation layer can form an insulation structure at the sealing surface between the first box body and the second box body, avoiding insulation defects at the sealing surface.

[0044] Preferably, the lightweight flexible thermal insulation layer includes a polymer foam material layer or an aerogel felt layer. These thermal insulation materials have a certain deformation capacity and can adapt to the slight deformation of the polymer composite shell during use, avoiding separation from the shell or causing the material to crack. Polymer foam material is a microporous material based on polymer (plastic, rubber, elastomer or natural polymer material) with countless bubbles inside. Typical foaming materials include polyurethane foam, polystyrene foam, etc. Aerogel felt is based on silica aerogel as the main material and is compounded in reinforcing fibers. It has the characteristics of softness, easy cutting, low density, inorganic fireproofing, overall hydrophobicity, and green environmental protection. In the present application, it is further preferred that the lightweight flexible thermal insulation layer is an aerogel felt layer.

[0045] The preferred protective layer is a thin layer of fireproof material. The preferred thin layer of fireproof material includes a fireproof cloth layer or a metal foil layer. On the one hand, the protective layer plays a role in physically isolating the heat insulation layer from the battery cells or electrical components in the battery box, avoiding the reduction of thermal insulation performance caused by the falling or scattering of the heat insulation layer material and the interference with the normal operation of the battery box or the battery cells or electrical components in the battery box. On the other hand, the protective layer can also play a certain role in heat insulation and can reduce the loss of heat from the inside of the battery box. The use of a thin layer of fireproof material can reduce weight. The metal thin layer is preferably a fireproof cloth layer.

[0046] Preferably, the box cover shell and the heat insulating layer, as well as the heat insulating layer and the protective layer are fixed by bonding.

[0047] Preferably, the sealing member covers a seam between the first outer box shell and the first inner box shell;

[0048] And / or, the sealing member covers a seam between the second outer casing and the second inner casing.

[0049] In the technical solution, the heat insulation and sealing effect is improved by covering the joint between the outer box shell and the inner box shell.

[0050] Preferably, the sealing member is also sandwiched between the first inner box shell and the second inner box shell.

[0051] In this technical solution, the heat insulation and sealing effect is improved.

[0052] A battery pack, comprising:

[0053] A battery cell, the battery cell comprising:

[0054] In the box assembly of the battery pack, the battery cells are arranged in a space defined by the first box and the second box.

[0055] In this technical solution, the battery unit is prevented from being affected by the external environment.

[0056] The positive and progressive effects of the present invention are:

[0057] In the present technical solution, sealing is performed by combining the sealing groove of the box, the sealing member arranged in the sealing groove and the protrusion on the second box, which can effectively improve the sealing performance. Among them, the abutting portion of the sealing member is arranged in the sealing groove, and the abutting portion cooperates with the protrusion on the second box by setting a receiving portion, so that the sealing member forms a sealing surface with a larger area in the sealing groove at least at the end and both sides of the protrusion, thereby improving the sealing effect of the first box relative to the second box. In addition, while achieving a larger area of ​​sealing, the structure occupies a smaller box cross-sectional width, which saves space for the battery box in the width direction, is conducive to reducing the volume of the battery pack, and improves the energy density of the battery pack under the same battery pack volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a schematic diagram of the cross-sectional structure of a box assembly according to an embodiment of the present invention (I).

[0059] Figure 2 Schematic diagram of the cross-sectional structure of a sealing member according to an embodiment of the present invention.

[0060] Figure 3 It is a structural schematic diagram of a box assembly according to an embodiment of the present invention, wherein the second box is hidden.

[0061] Figure 4 for Figure 3 A partial schematic diagram of the box assembly is shown.

[0062] Figure 5It is a partial enlarged schematic diagram of a box assembly according to an embodiment of the present invention.

[0063] Figure 6 2 is a cross-sectional schematic diagram of a box assembly according to an embodiment of the present invention.

[0064] Figure 7 It is a schematic structural diagram of a first box body according to an embodiment of the present invention.

[0065] Figure 8 It is a schematic structural diagram of the upper box cover of the test example of the present invention.

[0066] Fig. 9 It is a schematic structural diagram of the lower box body of the test example of the present invention.

[0067] Description of Reference Numerals

[0068] First box body 100, first outer box shell 110, first inner box shell 120, reinforcement plate 130

[0069] The second box body 200, the second outer box shell 210, the concave-convex structure 211, the second inner box shell 220, the heat insulation layer 221, the protective layer 222

[0070] Bump 1

[0071] Seal groove 2

[0072] Seal 3, abutment portion 31, accommodation portion 32, protruding portion 33

[0073] External seam 4

[0074] Flanging 5

[0075] Protrusion 6, first sealing surface 61, second sealing surface 62

[0076] Seam 7, first seam 71, second seam 72, third seam 73

[0077] Reinforcement structure 8, recessed area 81

[0078] Reinforcement 9 DETAILED DESCRIPTION

[0079] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0080] like Figure 1 and Figure 2As shown, the present invention discloses a box assembly of a battery pack, which includes a first box 100 as a lower box, a second box 200 as an upper box, and a seal 3. The first box 100 and the second box 200 are arranged in combination, and a sealing groove 2 is provided on the first box 100. The second box 200 is provided with a protrusion 1 corresponding to the depression of the sealing groove 2, and the protrusion 1 is consistent with the extension direction of the sealing groove 2. The seal 3 includes an abutting portion 31 arranged in the sealing groove 2, and a receiving portion 32 is provided on the surface of the abutting portion 31 facing the protrusion 1, and the extension direction of the receiving portion 32 is consistent with the extension direction of the sealing groove 2, and the receiving portion 32 receives and contacts the protrusion 1.

[0081] The sealing performance can be effectively improved by sealing the sealing groove 2 of the box, the sealing member 3 arranged in the sealing groove 2 and the protrusion 1 on the second box 200. Among them, the abutting portion 31 of the sealing member 3 is arranged in the sealing groove 2, and the abutting portion 31 cooperates with the protrusion 1 on the second box 200 by setting the accommodating portion 32, so that the sealing member 3 forms at least one horizontal seal and two vertical seals in the sealing groove 2, so as to improve the sealing effect of the first box 100 relative to the second box 200. In addition, while achieving a large area of ​​sealing, the structure occupies a small box cross-sectional width, which saves space for the battery box in the width direction, is conducive to reducing the volume of the battery pack, and improves the energy density of the battery pack under the same battery pack volume.

[0082] like Figure 1 and Figure 2 As shown, along the direction from the second box body 200 to the first box body 100, the two side surfaces of the protrusion 1 gradually approach each other, and the two side surfaces of the protrusion 1 fit with the accommodating portion 32. The two sides of the protrusion 1 contact with the sealing member 3 through the inclined surfaces, thereby improving the sealing effect.

[0083] In this embodiment, the first box 100 and the second box 200 are stacked up and down. In other embodiments, the first box 100 and the second box 200 can also be combined in other directions, and the box assembly can be sealed when combined in other directions.

[0084] In this embodiment, the first box body 100 and the second box body 200 are both made of polymer composite materials, and have good thermal insulation effect. The first box body 100 includes a first outer box shell 110 located on the outside and a first inner box shell 120 located on the inside, and the seal 3 is at least sandwiched between the first outer box shell 110 and the second box body 200. As the lower box body, the first box body 100 has relatively large load-bearing requirements and self-strength requirements. Therefore, by adopting the scheme of the box body of the composite material formed by the combination of the inner and outer box shells, the first box body 100 has the advantages of high self-strength and good thermal insulation effect. By setting the seal 3 between the first outer box shell 110 and the second box body 200, the sealing of the place is achieved, and the influence of the external environment temperature on the first inner box shell 120 of the first box body 100 is reduced. In other embodiments, the first outer box shell 110 can abut the side of the seal 3 to increase the deformation of the seal 3, thereby enhancing the sealing effect. The first outer box shell 110 can abut against the protruding portion of the seal 3, increasing the abutting surface between the first outer box shell 110 and the seal 3, thereby enhancing the sealing effect. The depression on the first outer box shell 110 cooperates with the protrusion 6 on the seal 3 to increase the connection between the first outer box shell 110 and the first box body 100, thereby enhancing the sealing effect.

[0085] like Figure 1 and Figure 2 As shown, a joint 7 is formed between the first outer box shell 110 and the first inner box shell 120, and the first joint 71 between the first outer box shell 110 and the first inner box shell 120 is completely closed by the sealing member 3, thereby improving the sealing effect.

[0086] like Figure 1 and Figure 7As shown, the second box body 200 includes a second inner box shell 220 located on the outside and a second inner box shell 220 located on the inside, and the second inner box shell 220 is arranged on the side surface of the second outer box shell 210 facing the first box body 100. The second box body 200, which serves as the upper box body, also adopts the combination of inner and outer box shells, which can increase the structural strength and reduce the influence of the external ambient temperature on the box assembly of the battery pack. The second inner box shell 220 includes a lightweight flexible insulation layer and a protective layer, and the surface of the first box body 100 located on the inner side of the sealing groove 2 is against the second inner box shell 220. The lightweight flexible insulation layer and the protective layer form an insulation layer, which has a certain degree of softness and can be compressed a small amount, so that the insulation layer can form an insulation structure at the sealing surface between the first box body 100 and the second box body 200, avoiding insulation defects at the sealing surface. In this embodiment, the lightweight flexible insulation layer uses aerogel felt, and the protective layer uses fireproof cloth. In other embodiments, the lightweight flexible insulation layer can also be a polymer foam material, which is a microporous material based on a polymer (plastic, rubber, elastomer or natural polymer material) with countless bubbles inside. Typical foam materials include polyurethane foam, polystyrene foam, etc.; the protective layer can also be a metal foil layer, such as aluminum foil.

[0087] like Figure 1 and Figure 2 As shown, the seal 3 covers the joint 7 of the second outer box shell 210 relative to the second inner box shell 220. The heat insulation sealing effect is improved by covering the second joint 72 between the second outer box shell 210 and the second inner box shell 220. The seal 3 is sandwiched between the first inner box shell 120 and the second inner box shell 220, thereby improving the heat insulation sealing effect.

[0088] The seal 3 includes a protruding portion 33, and at least one side edge of the abutting portion 31 of the seal 3 arranged in the sealing groove 2 extends outward to form the protruding portion 33, and the protruding portion 33 is sandwiched between the first box 100 and the second box 200. The protruding portion 33 formed by the outward extension of at least one side edge of the abutting portion forms a seal between the first box 100 and the second box 200, thereby enhancing the sealing performance of the box assembly. The protruding portion 33 is located at the outer side of the combination of the first box 100 and the second box 200 relative to the abutting portion 31, and the protruding portion 33 of the seal 3 is relatively arranged at the outer side of the abutting portion 31, thereby improving the sealing effect of the seal 3 on the combination of the first box 100 and the second box 200 at the outer joint, so as to prevent water, air, dust, etc. from the external environment from entering the joint of the first box 100 and the second box 200. In addition, the sealing surface formed between the protruding portion 33 and the box first faces the water, air, dust, etc. of the external environment, and can block foreign substances. In other embodiments, the extension part is located inside the first box body 100 and the second box body 200 relative to the abutting portion 31, so that water and air in the external environment can be prevented from affecting the sealing of the extension part while the extension part abuts.

[0089] like Figure 1 and Figure 2 As shown, there is a height difference between the two side edges of the abutting portion 31 of the seal 3, and one side of the two sides of the abutting portion 31 is outward and the other side is inward. By making the two sides of the seal 3 have a height difference, when the seal 3 is clamped between the first box body 100 and the second box body 200, the two ends of the seal 3 have different deformation amounts. Through this asymmetric distribution of deformation, the tightness of the fit between the seal 3 and the first box body 100 and the second box body 200 is improved. The setting of the sealing groove 2 with high outside and low inside allows the thermal insulation material of the upper cover to extend to the inside of the protrusion 1, thereby improving the thermal insulation effect, and an extension portion 33 is provided on the outside of the sealing strip to improve the sealing performance. In other embodiments, the setting of the sealing groove 2 with low outside and high inside can make it difficult for water and air in the external environment to pass through the receiving groove and enter the interior of the box assembly due to the influence of gravity.

[0090] like Figure 1 and Figure 3As shown, the extension portion is higher than the abutment portion 31, and the extension portion 33 is higher than the external seam 74 formed by the combination of the first box body 100 and the second box body 200. By setting the extension portion 33 relatively located outside the seal 3 at a high position, and setting the extension portion 33 at a position higher than the external seam 74 of the first box body 100 and the second box body 200, it is difficult for external liquids such as rainwater to extend into the position of the seal 3 through the external seam 74 of the first box body 100 and the second box body 200 under the action of gravity, thereby improving the sealing performance against external liquids. In other embodiments, the extension portion 33 is higher than the abutment portion 31 or the extension portion 33 is higher than the external seam 74 formed by the combination of the first box body 100 and the second box body 200. The extension portion 33 is higher than the abutment portion 31, and the extension portion 33 can block water and air in the external environment, thereby improving the sealing performance against external liquids. The protruding portion 33 is higher than an outer seam 74 formed by the first box body 100 and the second box body 200 , and the protruding portion 33 can block the outer seam 74 .

[0091] like Figure 3 and Figure 4 As shown, the edge of the second box 200 is provided with a flange 5, and the flange 5 extends toward the peripheral side of the first box 100 in a direction away from the second box 200. The edge of the second box 200 has a downward flange 5, which can play a role of squeezing the sealing member 3 from the outside in a horizontal direction together with the protrusion 1 on the second box 200, so that the sealing of the box is more reliable. At the same time, it can prevent rainwater from falling into the box assembly.

[0092] like Figure 1 and Figure 5 As shown, the flange 5 is arranged on the edge of the second outer box shell 210, and the flange 5 faces and abuts against the peripheral surface of the first outer box shell 110. The flange 5 on the second outer box shell 210 and the outer peripheral side of the first inner box shell 120 abut against each other, which can prevent water and air from entering the box assembly. The flange 5 forms a third seam 73 on the outer peripheral surface of the first inner box shell 120, and the third seam 73 is far away from the external seam 74, which can reduce the water and air that have entered the third seam 73 from entering the external seam 74.

[0093] like Figure 5 As shown, a reinforcing plate 130 is disposed on the outer circumferential surface of the first box body 100 , and the reinforcing plate 130 can reinforce the first box body 100 to increase the structural strength of the first box body 100 .

[0094] The reinforcing plate 130 can be used to fix the quick-change unit or the battery pack fixing unit. By installing a suitable quick-change unit or battery pack fixing unit, the battery pack can be used in electric vehicles of types such as quick-change electric vehicles (the battery pack is detachably connected to the vehicle body, and can be quickly separated from the vehicle and the battery), rechargeable electric vehicles (the battery pack is fixed to the vehicle body, and is loaded on the vehicle body for charging as the main means of energy replenishment), and electric vehicles with both quick-change and charging functions.

[0095] Quick-change unit The quick-change unit includes but is not limited to: electric / liquid cooling connector, locking mechanism, etc. The locking mechanism includes a threaded locking mechanism (a locking mechanism that fixes the battery box to the body by multiple bolts), a locking pin locking mechanism (a locking mechanism that fixes the battery box to the body by a locking pin locking method), a rotation locking mechanism (a locking mechanism that fixes the battery box to the body by a rotation locking method), a flip locking mechanism (a locking mechanism that fixes the battery box to the body by a flip locking method), a top-pressing locking mechanism (a locking mechanism that fixes the battery box to the body by a top-pressing locking method), a staggered tooth locking mechanism (a locking mechanism that fixes the battery box to the body by a staggered tooth locking method), a latch locking mechanism (a locking mechanism that fixes the battery box to the body by a latch locking method), and a push-pull locking mechanism (a locking mechanism that fixes the battery box to the body by a push-pull locking method). This embodiment adopts a staggered tooth locking mechanism composed of a lock shaft and a guide block.

[0096] 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 connection, etc.).

[0097] In this embodiment, a quick-change unit consisting of a staggered-tooth locking assembly composed of a lock shaft and a guide block and an electrical connector is fixed on the reinforcing plate 130 .

[0098] The outward side of the protruding portion 33 abuts against the surface of the flange 5. By making the outward side of the protruding portion 33 abut against the flange 5, a sealing surface is added, and the flange 5 located on the outside of the second box body 200 and the protrusion 1 located on the inside of the second box body 200 play a cooperative extrusion role on the sealing member 3, and the protruding portion 33 of the sealing member 3 can be pressurized from both sides in the horizontal direction to reliably compress the protruding portion 33, so as to prevent the protruding portion 33 from extending outward again when the first box body 100 and the second box body 200 are clamped, thereby reducing the sealing effect.

[0099] like Figure 1 and Figure 6 As shown, the surface of the seal 3 facing the sealing groove 2 is provided with a plurality of protrusions 6. Providing the protrusions 6 can increase the degree of compression between the seal 3 and the sealing groove 2, thereby improving the sealing effect.

[0100] The protrusion 6 includes a first sealing surface 61, which is arranged in the direction of the sealing groove 2, and the angle formed by the first sealing surface 61 and the surface of the sealing member 3 is an obtuse angle. The second sealing surface 62 is arranged in the direction opposite to the sealing groove 2, and the first sealing surface 61 is adjacent to the second sealing surface 62, and the angle formed by the second sealing surface 62 and the surface of the sealing member 3 is a right angle or an acute angle. Through the above-mentioned structural arrangement, when the sealing member 3 is installed in the sealing groove 2, the resistance caused by the protrusion 6 to the installation of the sealing member 3 is reduced, and at the same time, when the sealing member 3 is removed from the sealing groove 2, the resistance caused by the protrusion 6 to the removal of the sealing member 3 is increased.

[0101] like Figure 1 and Figure 2 As shown, the surface of one side of the seal 3 where the protrusion 6 is provided is wedge-shaped. The seal 3 can increase the sealing performance relative to the sealing groove 2 through this wedge shape, and can prevent the seal 3 from being separated from the protrusion 1.

[0102] like Figure 1 and Figure 3 As shown, the present invention further discloses a battery pack, which includes a battery cell and a box assembly of the battery pack. The battery cell is arranged in a space defined by a first box 100 and a second box 200 to prevent the battery cell from being affected by the external environment.

[0103] Test example

[0104] A quick-swap electric vehicle currently uses a sheet metal battery pack (using mica sheets as insulation material), which weighs 371.5 kg. Prepare a non-metal composite battery pack with the same size specifications (external dimensions and internal space dimensions of the battery box) as the sheet metal battery pack.

[0105] Both the sheet metal battery pack and the non-metal composite battery pack have a battery box formed by a combination of an upper box cover (second box body 200) and a lower box body (first box body 100).

[0106] like Figure 8As shown, the upper box cover of the non-metallic composite battery box adopts the second box body 200 in the above embodiment 2: the upper box cover (second box body 200) includes a box cover outer shell (second outer box shell 210), an insulating layer 221 and a protective layer 222 (the two together constitute the second inner box shell 220), and the insulating layer 221 and the protective layer 222 are sequentially covered and fixed to the box cover outer shell (second outer box shell 210) facing the side of the lower box body (first box body 100). In addition, the box cover shell (second outer box shell 210) is molded with SMC material, the lightweight and flexible insulation layer 221 is made of 5 mm thick aerogel felt, the protective layer 222 is made of fireproof cloth, the box cover shell (second outer box shell 210) and the lightweight and flexible insulation layer 221 as well as the insulation layer 221 and the protective layer 222 are connected by structural adhesive bonding, and a concave-convex structure 211 is arranged on the box cover shell (second outer box shell 210) to increase strength.

[0107] like Fig. 9 As shown, the lower box body (first box body 100) of the non-metallic composite battery box adopts the first box body 100 in Example 2. The lower box body includes an outer shell (first outer box shell 110) and an inner shell (first inner box shell 120) stacked and arranged, and the side wall of the outer shell (first outer box shell 110) extends outward to form a reinforcing structure 8, and the reinforcing structure 8 is provided with a recessed area 81 to achieve weight reduction while ensuring strength, and criss-cross reinforcing ribs 9 are provided between the inner shell (first inner box shell 120) and the outer shell (first outer box shell 110), and the reinforcing ribs 9 are formed on the upper surface of the outer shell (first outer box shell 110) (and the surface of the outer shell facing the inner shell), and are connected by bonding to the inner shell, and the inner shell (first inner box shell 120) and the outer shell (first outer box shell 110) are separated into a plurality of chambers by the reinforcing ribs 9 to form a chamber structure. The height of the chamber structure between the outer shell and the inner shell (i.e., the distance between the opposite surfaces of the outer shell and the inner shell) is 5 mm, and both the outer shell and the inner shell are molded by SMC. The lower box formed when no aerogel is placed in the chamber structure is recorded as the non-metallic composite lower box A, and the lower box formed when aerogel is placed in the chamber structure is recorded as the non-metallic composite lower box B. The non-metallic composite lower box A and the non-metallic composite lower box B are respectively combined with the upper box cover (the second box 200) by snap-fitting to form a non-metallic composite battery box, which are respectively recorded as non-metallic composite battery box A and non-metallic composite battery box B. After the battery modules and necessary electrical components are respectively loaded, the non-metallic composite battery pack A and non-metallic composite battery pack B are formed.

[0108] The upper box cover and the lower box body are sealed by a U-shaped seal. A recessed portion 320 is provided on the side of the upper box cover (second box body 200), which cooperates with a raised portion 310 provided on the side of the lower box body (first box body 100) to form a snap connection. The upper box cover (second box body 200) and the lower box body (first box body 100) are molded at one time to achieve the snap connection structure.

[0109] Non-metal composite battery pack A, non-metal composite battery pack B and sheet metal battery pack of the same size and specifications were tested.

[0110] In terms of weight testing, the mass of the non-metallic composite lower box B is 45kg, while the mass of the sheet metal lower box of the same size (using mica sheets as insulation material) is 60.4kg. Compared with the sheet metal lower box, the non-metallic composite lower box B has a weight reduction of 25.5%. The weight of the non-metallic composite battery box B is 57.8kg, and the weight of the sheet metal battery box is 70.772kg. The weight advantage of the non-metallic composite battery box is obvious. Compared with the non-metallic composite lower box B, the non-metallic composite lower box A lacks the aerogel felt placed in the chamber structure. Since the density of the aerogel felt is small and the amount used is not large, the mass of the non-metallic composite lower box A is equivalent to that of the non-metallic composite lower box B, which is slightly reduced (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 reduced by 2-3% compared with the sheet metal battery pack, and the weight advantage is obvious.

[0111] In terms of strength testing, the non-metal composite lower box A and non-metal composite lower box B, as well as the non-metal composite upper cover used to form a composite non-metal battery box, all meet the strength and other requirements specified in GB / T 31467.3-2015 "Lithium-ion power battery packs and systems for electric vehicles Part 3: Safety requirements and test methods" (the actual test can reach 1.5 times the standard). They can be used in electric vehicles.

[0112] In terms of thermal insulation and heat preservation performance: the initial temperature inside the package is 20-30℃, and it is placed in an environment of 7-9℃ for 600 minutes. The cumulative temperature change rate (cumulative cooling rate) of the battery cells in the non-metallic composite battery pack A is lower than 50% of that in the sheet metal battery pack (the temperature of the battery cells is measured by optical fiber), and the cumulative temperature change rate of the battery cells in the non-metallic composite battery pack B is only about 40% of that in the sheet metal battery pack. At lower temperatures, this advantage is more obvious. When used in cold northern regions, it can ensure that the temperature of the battery cells is at an optimal operating temperature. Moreover, after testing, non-metallic composite battery pack A and non-metallic composite battery pack B can withstand high temperatures of 1000℃. In the test simulating battery fire, even if the battery is completely burned, the non-metallic composite box remains basically intact throughout the test, with only smoke but no open flames.

[0113] The cell placement cavity of non-metallic composite battery pack A and non-metallic composite battery pack B is filled with thermal conductive glue (the height of the thermal conductive glue is about 1 / 3 of the battery height), which increases the temperature uniformity between the cells and avoids thermal runaway caused by abnormal temperature of individual cells. Secondly, it also makes the cells (or battery modules formed by cells) inside the battery box form a whole, increasing the overall strength of the battery pack. Compared with the sheet metal battery pack in the above case, the non-metallic composite material battery pack B has a cumulative temperature rise of more than 5°C when charged with a charging current of 40A (SOC from 0-100%) in the same environment. The non-metallic composite material battery pack B has a charging capacity that is more than 5% higher than the sheet metal battery pack, and the maximum temperature difference inside the box of the composite non-metal battery pack (obtained by recording the temperature of all positive and negative ears) is maintained at a uniformity of 1.5-2°C. This is not only related to the use of thermal conductive adhesive, but also related to the fact that the specific heat capacity and thermal insulation performance of SMC are higher than those of sheet metal materials. The above factors make the non-metallic composite material battery pack of this application more advantageous than the sheet metal battery pack in avoiding thermal runaway.

[0114] The properties of some of the raw materials used in the above test examples are as follows:

[0115] SMC meets the following performance requirements: Material grade (disordered glass fiber state) tensile strength ≥70Mpa (GB / T 1447-2005), flexural strength ≥160MPa (GB / T 1449-2005), impact toughness ≥55KJ / m 2 (GB / T 1451-2005), elongation at break ≥1.3% (GB / T 1447-2005).

[0116] The density of aerogel felt is about 0.16 mg / cm 3 .

[0117] Structural adhesive shear strength (anodized aluminum-anodized aluminum) ≥ 6MPa, tensile strength ≥ 5MPa, flame retardant grade V0.

[0118] The above-mentioned SMC, aerogel felt and structural adhesive can be commercial products or homemade products that meet the above performance requirements, and the remaining materials are commercial products. Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only an example, and the scope of protection of the present invention is defined by the attached 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 scope of protection of the present invention.

Claims

1. A box assembly of a battery pack, characterized in that: The box assembly of the battery pack includes: A first box body and a second box body, wherein the first box body and the second box body are combined and arranged, the first box body is provided with a sealing groove, and the second box body is provided with a protrusion corresponding to the depression of the sealing groove, and the protrusion is consistent with the extending direction of the sealing groove; A sealing member, the sealing member comprising an abutting portion disposed in the sealing groove, the abutting portion having a surface facing the protrusion and provided with a receiving portion, the receiving portion receiving and contacting the protrusion; The first box body is a lower box body, and the second box body is an upper box body. Both the first box body and the second box body are made of polymer composite materials. The first box body includes a first outer box shell located on the outside and a first inner box shell located on the inside. The sealing member is at least sandwiched between the first outer box shell and the second box body. The second box body includes a second outer box shell located on the outside and a second inner box shell located on the inside. The second inner box shell is arranged on a side surface of the second outer box shell facing the first box body. The sealing member is also sandwiched between the first inner box shell and the second inner box shell. The sealing member covers a seam between the first outer shell and the first inner shell; and / or, The sealing member covers a seam between the second outer casing and the second inner casing.

2. The box assembly of the battery pack according to claim 1, characterized in that: The sealing member further includes a protruding portion. At least one side edge of the abutting portion extends outward to form the protruding portion. The protruding portion is sandwiched between the first box body and the second box body.

3. The box assembly of the battery pack according to claim 2, characterized in that: The protruding portion is located on an outward side of a combination of the first housing and the second housing relative to the abutting portion.

4. The box assembly of the battery pack according to claim 1, characterized in that: There is a height difference between the edges on both sides of the abutting portion of the seal.

5. The box assembly of the battery pack according to claim 3, characterized in that: The first box is a lower box, and the second box is an upper box; The protruding portion is higher than the abutting portion, And / or, the protruding portion is higher than an outer seam formed by the combination of the first box body and the second box body.

6. The box assembly of the battery pack according to claim 5, characterized in that: The edge of the second box body is provided with a flange, and the flange extends toward the peripheral side of the first box body in a direction away from the second box body.

7. The box assembly of the battery pack according to claim 6, characterized in that: The outward side of the protruding portion abuts against the flange surface.

8. The box assembly of the battery pack according to claim 1, characterized in that: The surface of the sealing member facing the sealing groove is provided with a plurality of protrusions.

9. The box assembly of the battery pack according to claim 8, characterized in that: The protrusion comprises: a first sealing surface, the first sealing surface is arranged toward the sealing groove, and an angle formed between the first sealing surface and the surface of the sealing member is an obtuse angle, The second sealing surface is arranged in a direction opposite to the sealing groove, the first sealing surface is adjacent to the second sealing surface, and the angle formed by the second sealing surface and the surface of the sealing member is a right angle or an acute angle.

10. The box assembly of the battery pack according to claim 9, characterized in that: The protrusion is wedge-shaped on the surface of the sealing member.

11. The box assembly of the battery pack according to claim 1, characterized in that: Along the direction from the second box body to the first box body, the two side surfaces of the protrusion gradually approach each other, and the two side surfaces of the protrusion are in contact with the accommodating portion.

12. The box assembly of the battery pack according to any one of claims 1 to 11, characterized in that: The second inner box shell includes a lightweight flexible insulation layer and a protective layer; The surface of the first box body located inside the sealing groove abuts against the second inner box shell.

13. A battery pack, characterized in that: It includes: A battery cell, the battery cell comprising: According to the case assembly of the battery pack as described in any one of claims 1 to 12, the battery cell is arranged in a space defined by the first case and the second case.

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