Battery pack

Abstract

The utility model relates to the technical field of battery pack packaging, and provides a battery pack which comprises a box body and a battery module in the box body, the box body comprises an upper box body and a lower box body, the battery module is fixed at the bottom of the lower box body, and structural adhesive is filled between the battery module and the side wall of the lower box body in the lower box body. And the filling height of the structural adhesive is not less than half of the height of the battery module and does not exceed the upper surface of the battery module, so that the structural adhesive arranged between the battery module and the side wall of the lower box body can inhibit the bulging condition in the middle of a battery cell of the battery module when the battery pack is used for a long time.

Description

Technical Field

[0001] This utility model relates to the field of battery pack packaging technology, and in particular to a battery pack. Background Technology

[0002] With the advancement of new energy technologies, new energy has gradually permeated various fields, especially showing significant development in the automotive sector. Its advantages of low operating costs, energy conservation and environmental protection, high output power, and energy recovery have continuously expanded its reach in the new energy vehicle field, gradually giving rise to new energy sedans, new energy buses, and new energy mining trucks. As the market share of new energy mining trucks in mining areas increases, the harsh environment of mining areas causes high-amplitude, high-frequency vibrations during operation. This necessitates that the battery packs of new energy mining trucks possess stronger vibration and impact resistance. Existing technologies typically involve applying structural adhesive to the bottom of the lower housing of the battery pack, pressing and fixing the battery modules after they are installed in the housing, and using structural adhesive to enhance the fixation strength between the battery modules and the housing to prevent loosening.

[0003] To facilitate the insertion of battery modules into the battery pack, a gap is usually left between the battery module and the side wall of the pack. During long-term use of the battery pack, the battery cells of the battery module may bulge and deform. The gap between the pack walls and the battery modules has limited ability to suppress deformation, and the bulging and deformation of the cells can easily affect the normal use of the battery pack. Utility Model Content

[0004] The purpose of this utility model is to provide a battery pack that solves the problem in the prior art where the battery pack is easily affected by the bulging and deformation of the battery module cells, thus affecting the normal use of the battery pack.

[0005] The present invention provides a battery pack including a housing and a battery module inside the housing. The housing includes an upper housing and a lower housing. The battery module is fixed to the bottom of the lower housing. Structural adhesive is filled between the battery module and the side wall of the lower housing. The filling height of the structural adhesive is not less than half the height of the battery module and does not exceed the upper surface of the battery module.

[0006] Furthermore, the structural adhesive filling height inside the lower housing is at least 80% of the battery module height.

[0007] Furthermore, the casing has a square structure, and structural adhesive is used to fill the gaps between the four side walls of the lower casing and the battery module.

[0008] Furthermore, the depth of the lower housing's inner cavity is lower than the height of the battery module.

[0009] Furthermore, structural adhesive fills the space surrounding the battery module within the lower housing cavity, extending to the edge of the upper opening of the lower housing, with the filling height of the structural adhesive being the same as the depth of the lower housing.

[0010] Furthermore, the upper opening edge of the lower housing is provided with a horizontal flange that surrounds the upper opening, and the structural adhesive has a portion that overflows onto the horizontal flange so that the structural adhesive contacts the upper housing when the upper housing and the lower housing are joined.

[0011] Furthermore, the horizontal flange is also provided with grooves to accommodate structural adhesive that spills onto the horizontal flange.

[0012] Furthermore, the outer edge of the horizontal flange is provided with an upward-facing vertical baffle, and the vertical baffle around the horizontal flange forms a receiving space to accommodate the structural adhesive that overflows onto the upper surface of the horizontal flange.

[0013] Furthermore, the battery module is fixed to the bottom of the lower housing with bolts, and structural adhesive covers the bolt connection area.

[0014] Furthermore, the bottom of the lower casing is coated with a fixing adhesive, and the flowability of the structural adhesive when filling the gap between the battery module and the side wall of the lower casing is greater than that when applying the fixing adhesive.

[0015] Beneficial effects:

[0016] This utility model improves upon existing battery pack technology and provides a battery pack that, by filling the space between the battery module and the side wall of the lower housing with structural adhesive whose height is not less than half the height of the battery module and does not exceed the upper surface of the battery module, can suppress the bulging of the battery cells in the battery module that may occur during long-term use. This solves the problem that existing battery packs are prone to affecting normal use due to the deformation of the battery cells in the battery module. Attached Figure Description

[0017] Figure 1 This is an exploded view of the upper casing, lower casing, and battery modules of the battery pack in an embodiment of the present invention.

[0018] Figure 2 for Figure 1 A schematic diagram of the lower box structure.

[0019] In the diagram: 1. Upper housing; 2. Battery module; 3. Lower housing; 31. Horizontal flange. Detailed Implementation

[0020] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0021] The principle and concept of this utility model is to provide a battery pack in which adhesive is injected between the battery module and the side wall of the lower casing of the battery pack, and the injection height is not less than half the height of the battery module. When the battery pack is in normal use, the bulging and expansion of the battery module is suppressed by the solidified structural adhesive.

[0022] Based on the above principles, this utility model provides a battery pack and various embodiments thereof.

[0023] Based on the above principles, in a basic embodiment, such as Figure 1 , Figure 2 In the provided embodiment, the battery pack of this utility model includes a lower housing 3, a battery module 2, and an upper housing 1. The upper housing has a downward-facing lower opening, and the lower housing has an upward-facing upper opening. The openings of the upper housing and the lower housing are joined together to form the housing of the battery pack. The battery module is located inside the housing. The upper housing has a top wall and four side walls, and the lower housing has a bottom wall and four side walls. The bottom wall of the lower housing is its bottom. The battery module 2 is fixed at the bottom position of the lower housing 3. The battery module includes multiple battery cells stacked together, and the thickness direction of the battery cells is consistent with the stacking direction.

[0024] Structural adhesive is filled between the battery module and the side wall of the lower housing. The height of the structural adhesive is not less than half the height of the battery module 2, and the structural adhesive covers at least half of the area of ​​the battery module in the height direction. Furthermore, the height of the structural adhesive does not exceed the upper surface of the battery module 2, so as not to affect the upper components of the battery module. The structural adhesive used in this invention is preferably an adhesive with high structural strength after solidification. During normal use of the battery pack, if the battery module 2 bulges, the structural adhesive can provide support for the battery module. The structural adhesive in the lower housing 3 can effectively suppress the bulging deformation of the battery cells in the battery module 2. The bulging deformation of the battery cells mainly occurs in the central area. Therefore, the structural adhesive must at least cover the central area to suppress the bulging, thus solving the problem in the prior art where the bulging deformation of the battery module affects the normal use of the battery pack.

[0025] Based on the above embodiments, in one embodiment, such as Figure 1 , Figure 2 In the provided embodiments, the structural adhesive filling height between the side wall of the lower housing 3 and the battery module 2 is preferably not less than 80% of the height of the battery module 2, which can cover a larger area of ​​the side of the battery module 2 and provide more effective support for the upper-middle position where the bulging and expansion of the battery cell occurs. By increasing the height of the structural adhesive and increasing the area of ​​the structural adhesive covering the battery module 2, the effect of suppressing the bulging and deformation of the battery module 2 is improved. Of course, in other embodiments, the filling height of the structural adhesive can also be 90% or 70% of the height of the battery module, which can be selected as needed.

[0026] Based on the above embodiments, in one embodiment, such as Figure 1 , Figure 2In the provided embodiment, the battery pack housing is a square housing, and correspondingly, the lower housing 3 is a square structure with four side walls. Structural adhesive is filled between the four side walls of the lower housing 3 and the battery module 2, so that the structural adhesive can better surround the battery module 2 and form support on different sides of the battery module 2, thereby improving the ability to suppress bulging deformation. When the internal pressure of the battery cell is not higher than the threshold, it will not affect normal operation due to bulging. When it is higher than the threshold, pressure can be released from the pressure relief valve at the top.

[0027] It should be noted that in the embodiments provided by this utility model, there are three battery cell modules 2. The long sides of each battery module 2 are aligned and there are no open gaps between any two battery cell modules 2. The three battery modules 2 are connected to form a square battery. Structural adhesive is filled between the four sides of the square battery and the four side walls of the square box. In another embodiment, a battery is formed by connecting multiple battery modules in series, with open gaps between adjacent battery modules. The battery pack with this configuration is also filled with structural adhesive with a height of not less than 80% of the height of the battery modules in the gaps between the battery modules.

[0028] Based on the above embodiments, in one embodiment, such as Figure 1 In the provided embodiment, the inner depth of the lower housing 3 is lower than the height of the battery module 2. Since the battery module 2 needs to be installed into the lower housing 3 as a whole during the battery pack assembly process, if the inner depth of the lower housing 3 is lower than the battery module 2, the part of the battery module 2 that exceeds the lower housing 3 can be clamped and the battery module 2 can be placed in the lower housing 3. This avoids the situation where the clamping device for holding the battery module 2 cannot be inserted into the lower housing 3 due to the small gap between the battery module 2 and the lower housing 3, thus improving the convenience of the assembly operation of the battery module 2.

[0029] Based on the above embodiments, in one embodiment, such as Figure 1 , Figure 2 In the provided embodiment, structural adhesive fills the space surrounding the battery module 2 within the inner cavity of the lower housing 3, extending to the edge of the upper opening of the lower housing 3. Adhesive can be poured into the lower housing through the gap between the side wall and the battery module, utilizing the fluidity of the structural adhesive to fill the inner cavity. Thus, the height of the lower housing 3 is set to match a pre-set pouring height. Simply pouring the structural adhesive to the level of the lower housing 3 or slightly overflowing its upper edge ensures the appropriate pouring height. In this embodiment, the height of the lower housing 3 is preferably 80% of the height of the battery module 2, providing a height reference for pouring the structural adhesive, and the lower housing 3 filled with structural adhesive has higher structural strength.

[0030] Based on the above embodiments, in one embodiment, such as Figure 1In the provided embodiment, a horizontal flange 31 perpendicular to the side wall of the lower box 3 is provided around the upper opening edge of the lower box 3 to carry the structural adhesive that overflows from the lower box 3. When the lower box 3 and the upper box 1 are fixed together, the structural adhesive is pressed and fixed to the upper box 1. There is structural adhesive around the horizontal flange 31, which can not only enhance the fixation but also seal and waterproof between the upper and lower boxes.

[0031] Of course, the structural adhesive can also be applied without overflowing onto the horizontal flange 31 of the lower housing. The upper and lower housings can be connected solely by existing sealing rings and bolts. The flanges at the openings of the upper and lower housings are fixed with bolts and sealed by tightening the sealing rings. If there is structural adhesive between the upper and lower flanges, it can enhance the sealing and fixing effect.

[0032] Based on the above embodiments, in one embodiment, a groove is further provided on the horizontal flange 31 of the lower housing 3, extending along the direction of the horizontal flange 31, to accommodate structural adhesive overflowing from the lower housing 3. In another embodiment, an upward-curving vertical baffle is provided around the outermost periphery of the horizontal flange 31 of the lower housing 3. The top surface of the vertical baffle is lower than the top surface of the battery module, and the height of the vertical baffle is very small. The vertical baffle around the lower housing 3 forms a receiving space for accommodating structural adhesive, which can prevent the structural adhesive overflowing onto the horizontal flange 31 from continuing to overflow, improving the convenience of the adhesive filling operation.

[0033] Based on the above embodiments, in one embodiment, a plurality of threaded holes for fixing the battery module 2 are also provided in the lower housing 3. After the battery module 2 is fixed in the lower housing 3 by bolts, adhesive is then applied. The structural adhesive will cover the bolt connection part, which can strengthen the bolt connection strength and form a seal at the bolt connection.

[0034] Based on the above embodiments, in one embodiment, the bottom of the lower housing 3 is coated with a fixing adhesive. When assembling the battery pack, the fixing adhesive is first applied to the bottom of the lower housing 3. After the battery module 2 is placed into the housing, it is pressed tightly and fixed with bolts to position and fix the battery module 2. Then, adhesive is injected between the battery module 2 and the side wall of the lower housing 3. The structural adhesive used in this invention is preferably a structural adhesive with good fluidity. The fixing adhesive is a type of structural adhesive. The structural adhesive injected between the battery module 2 and the side wall of the lower housing 3 has greater fluidity than the structural adhesive applied to the bottom of the lower housing 3, so as to ensure that the structural adhesive can flow smoothly into the gap between the battery module 2 and the lower housing 3 during the injection process, and to ensure that the structural adhesive fills the gap densely. The structural adhesive applied to the bottom of the lower housing 3 is preferably a structural adhesive with higher viscosity, so as to more firmly bond and fix the battery module 2.

[0035] The lower housing 3 of the battery pack provided by this utility model has a height of 80% of the height of the battery module 2. During assembly, the part of the battery module 2 that is higher than the lower housing 3 can be clamped and the battery module 2 can be placed smoothly into the lower housing 3. During the filling of the adhesive, it is only necessary to fill the structural adhesive to the height of the overflow of the lower housing 3 to ensure that the height of the structural adhesive is 80% of the height of the battery module 2. This ensures that the structural adhesive will not affect the wires, pressure relief valve and other components on the top of the battery module 2, while suppressing the bulging deformation of the battery module 2. A horizontal flange 31 perpendicular to the side wall of the lower housing 3 is also provided around the opening of the lower housing 3. A groove and a vertical baffle are provided on the horizontal flange 31 along the extension direction of the horizontal flange 31. The vertical baffle provided around the horizontal flange 31 forms a receiving space to accommodate the overflow of structural adhesive. When the upper housing 1 and the lower housing 3 are fixed together, the structural adhesive in the receiving space can play a waterproof and sealing role.

[0036] The battery pack uses structural adhesive to fill and fix the battery module to the side wall of the lower casing, making the battery module 2 and the side wall of the lower casing 3 a whole. This suppresses cell bulging and deformation, and increases the overall strength of the battery pack, thereby improving the battery pack's main frequency. Tests have verified that the battery pack's main frequency is increased by 20%. The battery pack's vibration resistance is also improved, meeting the requirements for use in mining areas.

[0037] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A battery pack, comprising a housing and a battery module inside the housing, the housing comprising an upper housing and a lower housing, the battery module being fixed to the bottom of the lower housing, characterized in that, Structural adhesive is filled between the battery module and the side wall of the lower housing. The filling height of the structural adhesive is not less than half the height of the battery module and does not exceed the upper surface of the battery module.

2. The battery pack according to claim 1, characterized in that, The structural adhesive filling height inside the lower casing should be at least 80% of the battery module height.

3. The battery pack according to claim 1 or 2, characterized in that, The box has a square structure, and the four side walls of the lower box are filled with structural adhesive between themselves and the battery module.

4. The battery pack according to claim 1 or 2, characterized in that, The depth of the lower housing is lower than the height of the battery module.

5. The battery pack according to claim 4, characterized in that, Structural adhesive fills the space around the battery module inside the lower housing cavity, extending to the edge of the upper opening of the lower housing. The filling height of the structural adhesive is the same as the depth of the lower housing.

6. The battery pack according to claim 5, characterized in that, The lower housing has a horizontal flange around the upper opening edge, and the structural adhesive has a portion that overflows onto the horizontal flange so that the structural adhesive contacts the upper housing when the upper housing and the lower housing are joined.

7. The battery pack according to claim 6, characterized in that, The horizontal flange is also provided with a groove to accommodate structural adhesive that spills onto the horizontal flange.

8. The battery pack according to claim 6, characterized in that, The outer edge of the horizontal flange is provided with an upward-facing vertical guard. The vertical guard around the horizontal flange forms a receiving space to accommodate structural adhesive that overflows onto the upper surface of the horizontal flange.

9. The battery pack according to claim 1 or 2, characterized in that, The battery module is fixed to the bottom of the lower housing with bolts, and structural adhesive covers the bolt connection area.

10. The battery pack according to claim 1 or 2, characterized in that, The bottom of the lower casing is coated with a fixing adhesive. The flowability of the structural adhesive when filling the gap between the battery module and the side wall of the lower casing is greater than that when applying the fixing adhesive.

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