A battery box cover

Abstract

This utility model provides a battery box cover, including an upper frame, which is an open-side frame structure with liquid inlets and outlets on opposite side walls; a lower frame, which is also an open-side frame structure, with the upper frame fitted onto the lower frame and the two sealed together at the open end; a cavity flow channel, which is the gap between the upper and lower frames; and a fire-fighting device, which is embedded in the lower frame. Under normal operating conditions, the inner surface of the cover is in contact with the battery cell, and the coolant circulating in the cavity flow channel can effectively cool and exchange heat, reducing the surface temperature of the battery cell and extending its service life. When extreme thermal runaway occurs, the temperature in the cavity flow channel rises sharply, and the high temperature causes the fire-fighting device to activate and spray. The circulating cooling water is sprayed into the box under external pressure, rapidly reducing the temperature inside the box and quickly suppressing the spread of thermal runaway.

Description

Technical Field

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

[0002] With the rapid expansion and development of the new energy market, the market share of new energy vehicles is gradually increasing. New energy power batteries are usually secondary batteries, which are batteries that can be used again after being discharged by recharging to activate the active materials.

[0003] With the technological development of lithium-ion battery packs and the pursuit of the ultimate energy density and cost, the current metal box cover reduces the ultimate energy density requirement due to weight factors; while using composite materials can increase its energy density, but at the same time, due to thermal safety requirements, attaching protective materials such as mica will increase the cost to a certain extent.

[0004] Therefore, the use of PP and other plastic materials to replace the above two materials is considered. However, PP and other plastic materials have weak thermal shock resistance and may collapse and melt through, bringing certain risks of thermal runaway.

[0005] To address this risk of thermal runaway, we propose a specially designed cover structure. Utility Model Content

[0006] The purpose of this utility model is to overcome the shortcomings of the existing technology. To achieve the above objective, this utility model adopts the following technical solution: A battery case cover includes an upper frame, which is an open-side frame structure with liquid inlets and outlets on opposite side walls; a lower frame, which is also an open-side frame structure, with the upper frame fitted onto the lower frame and the two sealed together at the open end; a cavity flow channel, which is the gap between the upper and lower frames; and a fire-fighting device embedded in the lower frame. Under normal operating conditions, the inner surface of the cover is in contact with the battery cells, and the coolant circulating in the cavity flow channel effectively cools and exchanges heat, reducing the surface temperature of the battery cells and extending their service life. In the event of extreme thermal runaway, the temperature inside the cavity flow channel rises sharply, and the high temperature triggers the fire-fighting device to activate and spray. Circulating cooling water is sprayed into the case under external pressure, rapidly reducing the internal temperature and quickly suppressing the spread of thermal runaway.

[0007] More preferably, the fire-fighting device is a nozzle, the inlet end of the nozzle's spray hole is connected to the cavity flow channel, the outlet end of the spray hole is connected to the inner cavity of the lower frame, and a control valve is installed inside the spray hole.

[0008] More preferably, the control valve is a diaphragm, and both the inlet and outlet ends of the injection orifice are sealed with diaphragms.

[0009] More preferably, the control valve is a temperature-sensing valve.

[0010] More preferably, the fire-fighting device is a weak part, which is a thinned part on the lower frame. The thickness of the weak part is 20%-50% of the thickness of the lower frame 2 before thinning. The thickness of the weak part can be 20%, 30%, 40%, 50% of the thickness before thinning, or any value between two values.

[0011] More preferably, the upper frame includes an upper top plate and an upper side wall connected to the edge of the upper top plate. The upper side wall is an outwardly expanding quadrangular pyramid structure, and the bottom edge of the upper side wall is bent outward to provide an upper edge plate parallel to the upper top plate.

[0012] More preferably, the lower frame includes a lower top plate and a lower side wall connected to the edge of the lower top plate. The lower side wall is an outwardly expanding quadrangular pyramid structure, and the bottom edge of the lower side wall is bent outward to provide a lower edge plate parallel to the lower top plate.

[0013] More preferably, the upper top plate is parallel to the lower top plate, and the distance H between the upper top plate 11 and the lower top plate 21 is 10-100mm. The value of H can be 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, or any value within any two ranges.

[0014] More preferably, a connecting post connects the upper frame and the lower frame.

[0015] More preferably, both the upper frame and the lower frame are made of plastic; the material can be PE, PP, POM, PC, PS, PVC and other plastic materials.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention uses plastic instead of metal, which not only reduces the weight of the cover but also saves space. Furthermore, the cover has a cavity with a flow channel, and the coolant circulating in the cavity can effectively cool and exchange heat, reducing the surface temperature of the battery cells and extending their service life. In addition, the fire-fighting device inside the cover can cool down the thermally runaway battery cells in time, greatly reducing the risk of thermal spread in the battery pack and improving the safety performance of the battery pack. Attached Figure Description

[0017] Figure 1 A cross-sectional view of this utility model Figure 1 ; Figure 2 A cross-sectional view of this utility model Figure 2 ; Figure 3This is a three-dimensional schematic diagram of the present invention; Figure 4 This is a schematic diagram of the nozzle structure of this utility model. Figure 1 ; Figure 5 This is a schematic diagram of the nozzle structure of this utility model. Figure 2 .

[0018] In the figure: upper frame 1, lower frame 2, cavity flow channel 3, connecting column 4, nozzle 5, liquid inlet 6, liquid outlet 7, upper top plate 11, upper side wall 12, upper edge plate 13, lower top plate 21, lower side wall 22, lower edge plate 23. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0020] Reference Figures 1-3 A battery box cover includes an upper frame 1, which is a frame structure with an opening on one side, and liquid inlets 6 and liquid outlets 7 are provided on opposite side walls of the upper frame 1; a lower frame 2, which is a frame structure with an opening on one side, and the upper frame 1 is fitted onto the lower frame 2, and the two are sealed together at the opening end; a cavity flow channel 3, which is the gap between the upper frame 1 and the lower frame 2; and a fire-fighting device, which is embedded in the lower frame 2.

[0021] In some embodiments of this application, the inside of the box cover is provided with a cavity flow channel 3, which can be formed by processes such as blowing, hot melting, and welding.

[0022] In some embodiments of this application, the dimensions of the upper frame 1 are slightly larger than those of the lower frame 2. The upper frame 1 is fitted onto the lower frame 2, that is, the opening of the upper frame 1 is fitted over the top of the lower frame 2 (the end opposite to the opening) and welded to the bottom for sealing connection. In other words, after the opening of the upper frame 1 and the opening of the lower frame 2 are fitted together, they are welded to seal the connection. At this time, the upper top plate 11 of the upper frame 1 is parallel to the lower top plate 21 of the lower frame 2. The distance H between the upper top plate 11 and the lower top plate 21 is 10-100mm, and the H value is preferably 50mm. If the H value is too small (less than 10mm), the volume of the cavity flow channel 3 is small and the cooling effect is poor. If the H value is too large (greater than 100mm), the volume of the cavity flow channel 3 is too large, occupying more space and resulting in low battery energy density.

[0023] In some embodiments of this application, the liquid inlet 6 and the liquid outlet 7 are respectively connected to an external pipeline, which is connected to a backup water fire extinguishing system. Under normal operating conditions, the inner surface of the cover is in contact with the battery cell, and the coolant circulating in the cavity flow channel 3 can effectively cool and exchange heat, thereby reducing the temperature of the battery cell surface and extending the battery cell's service life.

[0024] In some embodiments of this application, the fire-fighting device is embedded in the lower frame 2. The fire-fighting device can be embedded in the lower top plate 21 or the lower side wall 22. The fire-fighting device is embedded and does not protrude from the inner surface of the lower frame 2, which saves space inside the box and does not interfere with the battery inside the box. At the same time, it also avoids the risk of the fire-fighting device being bumped by the battery inside the box, and improves the service life of the fire-fighting device.

[0025] In some embodiments of this application, when extreme thermal runaway occurs, the temperature inside the cavity flow channel 3 rises sharply, and the high temperature causes the fire-fighting device to activate and spray; the circulating cooling water is sprayed into the package under external pressure, which quickly reduces the temperature inside the package and rapidly suppresses the spread of thermal runaway.

[0026] like Figure 4 As shown, the fire-fighting device is a nozzle 5. The inlet end of the nozzle 5 is connected to the cavity flow channel 3, and the outlet end of the nozzle is connected to the inner cavity of the lower frame 2. A control valve is installed inside the nozzle. The control valve is a diaphragm, and the inlet and outlet ends of the nozzle are both sealed with diaphragms.

[0027] In some embodiments of this application, the fire-fighting device is a nozzle 5 embedded in the lower frame 2. The nozzle 5's spray hole is sealed with a diaphragm. Under normal operating conditions, the diaphragm blocks the spray hole, the nozzle 5 does not open, and the coolant only circulates within the cavity flow channel 3. When extreme thermal runaway occurs, the temperature inside the cavity flow channel 3 rises sharply. When the temperature reaches the melting temperature of the diaphragm, the diaphragm melts, the spray hole is opened, and the circulating cooling water is sprayed into the package under external pressure, rapidly reducing the temperature inside the package and quickly suppressing the spread of thermal runaway.

[0028] In some embodiments of this application, the diaphragm material may be plastic materials such as PE, PP, POM, PC, PS, and PVC.

[0029] like Figure 5 As shown, the control valve is a temperature-sensing valve.

[0030] In some embodiments of this application, the temperature-sensing valve is a thermistor, which senses changes in ambient temperature. When the temperature reaches a set value, the thermistor (such as a glass bulb) breaks, the spray hole is opened and sprays out, and circulating cooling water is sprayed into the package under external pressure, rapidly reducing the temperature inside the package and quickly suppressing the spread of thermal runaway.

[0031] The fire-fighting device is a weak point, which is a thinned section on the lower frame 2.

[0032] In some embodiments of this application, the lower frame 2 can be made of plastic materials such as PE, PP, POM, PC, PS, and PVC. Some thinning sections are locally provided on the lower top plate 21 and / or lower sidewall 22 of the lower frame 2. The thinning sections can be any shape such as circular, triangular, or quadrilateral. The thickness of the thinning sections is 20%-50% of the thickness of the lower frame 2. By locally thinning, weak sections are formed. When extreme thermal runaway occurs, the temperature inside the cavity flow channel 3 rises sharply. At this time, the weak section is melted. The circulating cooling water is sprayed into the package through the weak section under external pressure, which quickly reduces the temperature inside the package and rapidly suppresses the spread of thermal runaway.

[0033] The upper frame 1 includes an upper top plate 11 and an upper side wall 12 connected to the edge of the upper top plate 11. The upper side wall 12 is an outwardly expanding quadrangular pyramid structure. The bottom edge of the upper side wall 12 is bent outwardly to form an upper edge plate 13 parallel to the upper top plate 11. The lower frame 2 includes a lower top plate 21 and a lower side wall 22 connected to the edge of the lower top plate 21. The lower side wall 22 is an outwardly expanding quadrangular pyramid structure. The bottom edge of the lower side wall 22 is bent outwardly to form a lower edge plate 23 parallel to the lower top plate 21. The upper top plate 11 is parallel to the lower top plate 21.

[0034] In some embodiments of this application, the upper frame 1 covers the lower frame 2, the upper edge plate 13 is supported on the lower edge plate 23, and the upper edge plate 13 and the lower edge plate 23 are welded and sealed together. The cavity flow channel 3 is the gap between the upper top plate 11 and the lower top plate 21 and the upper side wall 12 and the lower side wall 22. Cooling water enters from the liquid inlet 6, passes through the cavity flow channel 3, and then flows out from the liquid outlet 7.

[0035] In some embodiments of this application, the upper edge plate 13 and the lower edge plate 23 connected together are provided with several through holes for connection. The upper and lower cover can be connected and fixed with bolts through the through holes to achieve the function of sealing and protecting the battery.

[0036] A connecting column 4 connects the upper frame 1 and the lower frame 2.

[0037] In some embodiments of this application, the connecting column 4 is disposed between the upper top plate 11 and the lower top plate 21, connecting the upper frame 1 and the lower frame 2, serving a reinforcing function, and at the same time creating a turbulent effect on the coolant in the cavity flow channel, which can effectively absorb heat.

[0038] In some other embodiments of this application, the connecting post 4 may also be disposed between the upper sidewall 12 and the lower sidewall 22 to serve as reinforcement and turbulence.

[0039] Both the upper frame 1 and the lower frame 2 are made of plastic.

[0040] In some embodiments of this application, the upper frame 1 and the lower frame 2 can be made of plastic materials such as PE, PP, POM, PC, PS, PVC, etc. By replacing metal materials with plastic materials, the weight of the lid can be reduced on the one hand, and the plastic material has an insulating effect on the other hand. The lid can be directly covered on the battery surface, saving space and improving space utilization and energy density.

[0041] This invention uses plastic instead of metal, which not only reduces the weight of the cover but also saves space. Furthermore, the cover has a cavity with a flow channel, and the coolant circulating in the cavity can effectively cool and exchange heat, reducing the temperature of the battery cell surface and extending the battery cell's lifespan. In addition, the fire-fighting device inside the cover can cool down the thermally runaway battery cells in time, greatly reducing the risk of thermal spread in the battery pack and improving the safety performance of the battery pack.

Claims

1. A battery box cover characterized by, include: The upper frame is a frame structure with an opening on one side, and liquid inlets and liquid outlets are provided on the opposite side walls of the upper frame; The lower frame is a frame structure with an opening on one side, and the upper frame is fitted onto the lower frame, with the two connected and sealed at the opening end. Cavity flow channel, wherein the cavity flow channel is the gap between the upper frame and the lower frame; Firefighting device, which is embedded in the lower frame.

2. The battery compartment cover of claim 1, wherein, The fire-fighting device is a nozzle. The inlet end of the nozzle's spray hole is connected to the cavity flow channel, and the outlet end of the spray hole is connected to the inner cavity of the lower frame. A control valve is installed inside the spray hole.

3. The battery compartment cover of claim 2, wherein, The control valve is a diaphragm, and both the inlet and outlet ends of the injection orifice are sealed with diaphragms.

4. The battery compartment cover of claim 2, wherein, The control valve is a temperature-sensitive valve.

5. The battery compartment cover of claim 1, wherein, The fire-fighting device is a weak point, which is a thinned section on the lower frame.

6. The battery compartment cover of claim 1, wherein, The upper frame includes an upper top plate and an upper side wall connected to the edge of the upper top plate. The upper side wall is an outwardly expanding four-sided pyramid structure, and the bottom edge of the upper side wall is bent outward to provide an upper edge plate parallel to the upper top plate.

7. The battery compartment cover of claim 6, wherein, The lower frame includes a lower top plate and a lower side wall connected to the edge of the lower top plate. The lower side wall is an outwardly expanding quadrangular pyramid structure, and the bottom edge of the lower side wall is bent outward to form a lower edge plate parallel to the lower top plate.

8. The battery compartment cover of claim 7, wherein, The upper top plate is parallel to the lower top plate.

9. The battery compartment cover of claim 1, wherein, A connecting column connects the upper frame and the lower frame.

10. The battery compartment cover of claim 1, wherein, Both the upper and lower frames are made of plastic.

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