A safe battery energy storage module

Abstract

The present invention discloses a safe battery energy storage module, which includes a battery pack shell and a pressure relief breathable valve. The pressure relief breathable valve includes: a main body, a valve body end cover, a floating valve core and a pressure limiting assembly. The main body is provided with a receiving cavity with openings at both ends, and the side wall of the main body is provided with an exhaust window. The floating valve core is accommodated in the receiving cavity. A reset elastic member is provided between the floating valve core and the valve body end cover, and a sealing ring is provided between the floating valve core and the main body. The floating valve core is provided with a breathable hole and a pressing plate. The pressing plate is provided with a through hole corresponding to the breathable hole, and a waterproof breathable membrane is provided between the pressing plate and the floating valve core. The floating valve core is provided with a hollow sleeve, and the pressure limiting assembly is provided in the sleeve. The battery energy storage module can improve the sensitivity during pressure relief, ensure that the pressure relief valve works according to the set conditions, and improve the safety of the battery energy storage module; at the same time, it provides necessary protection for the breathable membrane in extreme cases to extend the working life of the pressure relief valve.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage modules, and in particular to a safe battery energy storage module. Background Art

[0002] With the continuous development of science and technology, battery energy storage has been widely used. Usually, the battery pack needs to be waterproof and dustproof. In addition, due to the influence of factors such as the heating of the battery cells during charging and discharging and changes in the external environment, it is necessary to achieve gas breathing inside and outside the box to ensure the pressure balance inside and outside the box, thereby ensuring the reliability of the sealing structure. In addition, in extreme cases such as thermal runaway of the battery cell, the battery pack must be able to achieve rapid exhaust and pressure relief.

[0003] At present, most existing battery packs are equipped with a venting pressure relief valve, the basic structure of which is as follows: Figure 1 As shown. This type of breathable pressure relief valve 10 includes: a main body 11, a valve core 12, an elastic member 13 and a sealing member 14. The main body 11 is provided with an exhaust hole 15, the valve core 12 is provided with an air-permeable membrane, and the sealing member 14 is clamped between the valve core 12 and the main body 11. Under normal circumstances, the breathable pressure relief valve 10 plays a role of breathing and ventilation. The valve core 12 is pressed on the main body 11 by the elastic action of the elastic member 13, and the exhaust hole 15 of the main body 11 is blocked. The internal and external gases of the breathable pressure relief valve 10 can only be exchanged through the air-permeable membrane of the valve core 12, thereby achieving waterproof and dustproof; under extreme circumstances, the breathable pressure relief valve 10 plays a role of pressure relief. The high-pressure gas generated by the battery will prompt the valve core 12 to overcome the elastic force of the elastic member 13, so that the valve core 12 floats and does not block the exhaust hole 15 of the main body 11, and the high-pressure gas can be discharged to the outside of the breathable pressure relief valve 10 through the exhaust hole.

[0004] However, the existing venting pressure relief valve has the following defects:

[0005] On the one hand, after a period of time, the seal 14 is prone to aging problems, resulting in adhesion to the valve core 12, which will reduce the sensitivity of the valve body when releasing pressure. For example, the threshold of the breathable pressure relief valve is set at 2.4Mpa when leaving the factory, and the seal 14 will stick to the valve core 12 after aging. When the internal high-pressure gas reaches 2.4Mpa, the high-pressure gas cannot push the valve core 12, but will be discharged through the breathable membrane, which causes the breathable pressure relief valve 10 to fail to work as set;

[0006] On the other hand, the high-pressure gas generated in extreme conditions is usually accompanied by high temperature and even carries flying sparks. When the high-temperature gas and sparks pass through the breathable membrane, they will damage the breathable membrane. In this way, when the battery pack returns to normal from the extreme condition, the breathable membrane can no longer play a waterproof and dustproof role, resulting in the breathable pressure relief valve 10 being unable to continue to be used.

[0007] Therefore, how to design a safe battery energy storage module that can improve the sensitivity during pressure relief, ensure that the pressure relief valve works as set, and improve the safety of the battery energy storage module; at the same time, provide necessary protection for the breathable membrane under extreme conditions to extend the working life of the pressure relief valve, is a technical problem that technicians in this field need to solve. Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a safe battery energy storage module, so that it can improve the sensitivity during pressure relief, ensure that the pressure relief valve works according to the settings, and improve the safety of the battery energy storage module; at the same time, provide necessary protection for the breathable membrane under extreme conditions to extend the working life of the pressure relief valve.

[0009] The objective of the present invention is achieved through the following technical solutions:

[0010] A safe battery energy storage module, comprising a battery pack shell and a pressure relief vent valve arranged on the battery pack shell;

[0011] The pressure relief vent valve comprises: a main body, a valve body end cover, a floating valve core and a pressure limiting assembly, the main body is provided with a receiving cavity with two ends opened, a side wall of the main body is provided with an exhaust window, the valve body end cover is provided at one end of the main body, the floating valve core is accommodated in the receiving cavity, a reset elastic member is provided between the floating valve core and the valve body end cover; under the action of the reset elastic member, the edge of the floating valve core is pressed against the main body, and a sealing ring is provided between the floating valve core and the main body;

[0012] The floating valve core is provided with an air hole and a pressing plate, the pressing plate is located at the air hole, a through hole corresponding to the air hole is opened on the pressing plate, and a waterproof and breathable membrane is provided between the pressing plate and the floating valve core;

[0013] The floating valve core is provided with a hollow sleeve, the sleeve is aligned with the air vent, and the pressure limiting component is arranged in the sleeve; the pressure limiting component includes a shielding plate and a pressure limiting elastic member, the shielding plate can be movably accommodated in the sleeve, and the shielding plate is away from the compression plate of the floating valve core under the action of the pressure limiting elastic member.

[0014] In one of the embodiments, a blocking block and a cross beam are provided in the sleeve, and the pressure-limiting elastic member is a tension spring structure, and its two ends are respectively connected to the cross beam and the shielding plate; the shielding plate moves between the pressing plate and the blocking block, and under the action of the pressure-limiting elastic member, the shielding plate is pressed on the blocking block.

[0015] In one embodiment, the diameter of the air hole of the floating valve core is D1, the diameter of the through hole of the pressing plate is D2, the diameter of the shielding sheet is D3, and D2<D3<D1.

[0016] In one of the embodiments, a guide column is provided on the valve body end cover, a guide hole adapted to the guide column is opened on the floating valve core, and the guide column passes through the guide hole.

[0017] In one of the embodiments, the resetting elastic member is a cylindrical spring structure, the resetting elastic member is sleeved on the guide column, and two ends of the resetting elastic member are respectively abutted against the valve body end cover and the floating valve core.

[0018] In one embodiment, the valve body end cover is connected to the main body via threads.

[0019] In one of the embodiments, a waterproof gasket is provided on the main body, the waterproof gasket is arranged between the main body and the battery pack shell, and the waterproof gasket is made of rubber.

[0020] In one of the embodiments, the main body of the pressure relief vent valve is mounted on the battery pack shell by bolts, and the pressure relief vent valve is located below the battery pack shell.

[0021] In summary, the safety battery energy storage module of the present invention can improve the sensitivity during pressure relief, ensure that the pressure relief vent valve works according to the settings, and improve the safety of the energy storage module; at the same time, it provides necessary protection for the waterproof breathable membrane under extreme conditions to extend the working life of the pressure relief vent valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a structural schematic diagram of a traditional air-permeable pressure relief valve involved in the background technology;

[0024] Figure 2 It is a structural schematic diagram of the safety battery energy storage module of the present invention;

[0025] Figure 3 It is a structural schematic diagram of the pressure relief vent valve of the present invention (I);

[0026] Figure 4 It is a structural schematic diagram of the pressure relief vent valve of the present invention (II);

[0027] Figure 5 for Figure 4 An exploded schematic diagram of the pressure relief vent valve shown;

[0028] Figure 6 for Figure 4 A cross-sectional view of the pressure relief vent valve shown;

[0029] Figure 7 This is a schematic diagram of the internal state of the pressure relief vent valve under normal conditions;

[0030] Figure 8 Schematic diagram of the internal state of the pressure relief vent valve under extreme conditions. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0032] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] The present invention provides a safe battery energy storage module 20, such as Figure 2 As shown, it includes a battery pack shell 21 and a pressure relief vent valve 22 arranged on the battery pack shell.

[0035] Among them, Figure 3 , Figure 4 and Figure 5As shown, the pressure relief vent valve 22 includes: a main body 100, a valve body end cover 200, a floating valve core 300 and a pressure limiting assembly 400. The main body 100 is provided with a receiving cavity 110 with openings at both ends, and a venting window 101 is provided on the side wall of the main body 100. The valve body end cover 200 is provided at one end of the main body 100, and the floating valve core 300 is accommodated in the receiving cavity 110. A reset elastic member 210 is provided between the floating valve core 300 and the valve body end cover 200. Under the action of the reset elastic member 210, the edge of the floating valve core 300 is pressed against the main body 100, and a sealing ring 310 is provided between the floating valve core 300 and the main body 100.

[0036] like Figure 5 and Figure 6 As shown, the floating valve core 300 is provided with a vent hole 301 and a pressing plate 302, the pressing plate 302 is located at the vent hole 301, the pressing plate 302 is provided with a through hole 303 corresponding to the vent hole 301, and a waterproof breathable membrane 304 is provided between the pressing plate 302 and the floating valve core 300 (as shown in FIG. Figure 7 as shown).

[0037] like Figure 5 and Figure 6 As shown, the floating valve core 300 is provided with a hollow sleeve 320, the sleeve 320 is aligned with the air vent 301, and the pressure limiting assembly 400 is arranged in the sleeve 320. In addition, the pressure limiting assembly 400 includes a shielding sheet 410 and a pressure limiting elastic member 420, the shielding sheet 410 is movably accommodated in the sleeve 320, and the shielding sheet 410 is away from the pressing plate 302 of the floating valve core 300 under the action of the pressure limiting elastic member 420. When the pressure is released in an extreme case, the shielding sheet 410 will be attached to the waterproof breathable membrane 304 and the pressing plate 302 under the influence of the high-pressure gas, thereby blocking the air vent 301, so that the high-pressure gas can only push the floating valve core 300 and be discharged through the exhaust window 101. The specific working principle will be described below.

[0038] In this embodiment, if Figure 6 As shown, a blocking block 321 and a cross beam 322 are provided in the sleeve 320, and the pressure-limiting elastic member 420 is a tension spring structure, and its two ends are respectively connected to the cross beam 322 and the shielding sheet 410. The shielding sheet 410 moves between the pressing plate 302 and the blocking block 321, and under the action of the pressure-limiting elastic member 420, the shielding sheet 410 is pressed on the blocking block 321.

[0039] The diameter of the air hole 301 of the floating valve core 300 is D1, the diameter of the through hole 303 of the pressing plate 302 is D2, and the diameter of the shielding sheet 410 is D3, and D2<D3<D1. Since D3<D1, the shielding sheet 410 can move near the air hole 301; when the pressure is released, the shielding sheet 410 will be against the waterproof breathable membrane 304 and the pressing plate 302. Since D2<D3, the shielding sheet 410 can completely block the through hole 303, so that the internal high-pressure gas cannot be discharged through the waterproof breathable membrane 304.

[0040] In this embodiment, if Figure 5 As shown, the valve body end cover 200 is provided with a guide post 220, the floating valve core 300 is provided with a guide hole 330 adapted to the guide post 220, and the guide post 220 penetrates the guide hole 330. Preferably, the reset elastic member 210 is a cylindrical spring structure, the reset elastic member 210 is sleeved on the guide post 220, and the two ends of the reset elastic member 210 are respectively held against the valve body end cover 200 and the floating valve core 300.

[0041] It should be noted that the pressure relief vent valve 22 of the present invention is different from the conventional vent pressure relief valve 10 (such as Figure 1 Compared with the above (as shown in the figure), both can balance the air pressure inside and outside the battery pack housing 21, as well as quickly relieve pressure in extreme cases. Specifically, under normal circumstances, the battery will generate heat during the charging and discharging process, which in turn increases the internal air pressure, and part of the gas needs to be discharged to the outside. During the cooling process of the battery, the internal temperature drops, resulting in a decrease in air pressure, and external gas needs to be replenished to the inside. This cycle is called "breathing" of the battery pack, and the pressure relief vent 22 (the traditional breathable pressure relief valve 10) provides the necessary conditions for this. During this cycle, the discharge or inhalation of gas needs to pass through the waterproof breathable membrane 304 (the breathable membrane of the traditional breathable pressure relief valve 10), thereby ensuring that external dust and water vapor will not enter the battery pack.

[0042] However, the conventional venting pressure relief valve 10 has the following defects (refer to Figure 1 shown):

[0043] On the one hand, after a period of time, the seal 14 is prone to aging problems, resulting in adhesion to the valve core 12, which will reduce the sensitivity of the valve body when releasing pressure. For example, the threshold of the breathable pressure relief valve is set at 2.4Mpa when leaving the factory, and the seal 14 will stick to the valve core 12 after aging. When the internal high-pressure gas reaches 2.4Mpa, the pressure of the high-pressure gas cannot push the valve core 12, but will be discharged through the breathable membrane, which causes the breathable pressure relief valve 10 to fail to work as set;

[0044] On the other hand, the high-pressure gas generated in extreme conditions is usually accompanied by high temperature and even carries flying sparks. When the high-temperature gas and sparks pass through the breathable membrane, they will damage the breathable membrane. In this way, when the battery pack returns to normal from the extreme condition, the breathable membrane can no longer play a waterproof and dustproof role, resulting in the breathable pressure relief valve 10 being unable to continue to be used.

[0045] In view of these defects, the pressure relief vent valve 22 of the present invention is specially designed with a pressure limiting assembly 400 to ensure that the pressure relief vent valve 22 can work according to the set conditions, while preventing high-temperature gas and sparks from damaging the waterproof breathable membrane 304. In the following, in combination with the above structure, the working principle of the pressure relief vent valve 22 is specifically described:

[0046] Under normal circumstances, the state of the pressure relief vent valve 22 is as follows: Figure 7 As shown, the floating valve core 300 blocks most of the area of ​​the accommodating chamber 110. In this state, the gas discharge or inhalation needs to pass through the waterproof breathable membrane 304. Taking the gas discharge as an example, the gas path passes through: the sleeve 320, the gap of the blocking block 321, the breathable hole 301, the waterproof breathable membrane 304, the through hole 303 of the pressing plate 302, and finally discharged to the outside through the exhaust window 101 of the main body 100;

[0047] In extreme cases, the high pressure gas generated by the battery will cause the state of the pressure relief vent valve 22 to change to Figure 8 As shown. The change process is as follows. First, the high-pressure gas preferentially pushes the shielding sheet 410 to overcome the elastic force of the pressure-limiting elastic member 420, and then the shielding sheet 410 is pressed against the waterproof breathable membrane 304 and the pressing plate 302. At this time, the shielding sheet 410 completely covers the through hole 303 of the pressing plate 302. In this way, the high-pressure gas cannot be discharged from the air hole 301, and the pressure of the high-pressure gas will completely act on the floating valve core 300 (it can no longer leak out through the air hole 301). In this case, even if the aged sealing ring 310 is stuck to the floating valve core 300, the high-pressure gas can still push the floating valve core 300 open with a larger pressure, thereby destroying the adhesion of the sealing ring 310;

[0048] For example, the threshold of pressure relief is set at 2.4Mpa at the factory. When the internal high-pressure gas reaches 2.4Mpa, the shielding sheet 410 overcomes the elastic force and completely covers the through hole 303. At this time, the high-pressure gas cannot be discharged, and the internal air pressure will further rise until the thrust of the gas on the floating valve core 300 is greater than the sum of the elastic force of the reset elastic member 210 and the adhesive force of the sealing ring 310. At this time, the floating valve core 300 will be pushed, and a gap will be generated between the floating valve core 300 and the main body 100, and the high-pressure gas can be discharged to the outside through the gap and the exhaust window 101. After the battery temperature returns to normal, the pressure relief vent valve 22 will be reset to its normal state.

[0049] It is worth noting that in the above-mentioned pressure relief process, after the shielding sheet 410 completely covers the through hole 303, the internal air pressure will further rise, and the air pressure of the high-pressure gas will exceed 2.4Mpa (assuming it is 2.6Mpa). It can be understood that the original air pressure of 2.4Mpa can push the floating valve core 300, and the additional 0.2Mpa is to overcome the adhesion force generated by the aging of the sealing ring 310. Therefore, when the floating valve core 300 is pushed, the adhesion force of the sealing ring 310 disappears, the 2.6Mpa high-pressure gas will leak out quickly and its air pressure will drop back to 2.4Mpa. In other words, the air pressure inside the battery pack housing 21 will be maintained at the set threshold value of 2.4Mpa during stable pressure relief. In this process, the air pressure of the high-pressure gas will have a peak exceeding 2.4Mpa in a short period of time, but this will not affect the operation of the pressure relief vent valve 22. Because this peak pressure only occurs for a short time, it disappears after the floating valve core 300 is separated from the sealing ring 310, and then the 2.4Mpa high-pressure gas can still push the floating valve core 300 open, thereby maintaining the pressure relief. In contrast, when the internal pressure of the traditional breathable pressure relief valve 10 reaches 2.4Mpa, the valve core 12 cannot be opened due to stickiness, and the high-pressure gas will continue to leak out through the breathable membrane, which not only prevents the pressure from increasing rapidly to the level that can break through the stickiness limit, but also reduces the pressure relief sensitivity; it also causes the pressure relief time to be forced to increase in extreme cases, and it is impossible to achieve pressure relief and explosion prevention efficiently and quickly, which poses a safety hazard.

[0050] It should also be emphasized that when the pressure is released in extreme cases, the shielding sheet 410 is pressed against the waterproof breathable membrane 304 and the pressing plate 302, and most of the area of ​​the waterproof breathable membrane 304 will be blocked by the shielding sheet 410. In this way, the high-temperature gas no longer passes through the waterproof breathable membrane 304, and the flying sparks will not contact the waterproof breathable membrane 304, thereby avoiding the waterproof breathable membrane 304 from being damaged. When the battery returns to normal, the pressure relief breathable valve 22 can continue to work after being reset, achieving waterproof and dustproof, and balancing the air pressure inside and outside the battery pack shell 21.

[0051] Preferably, the valve body end cover 200 is connected to the main body 100 by a threaded connection (such as Figure 5 During assembly, the staff first installs the main body 100 on the battery pack housing 21, then connects the floating valve core 300 with the valve body end cover 200, and then inserts the two into the accommodating cavity 110 of the main body 100, and then tightens the valve body end cover 200, so that the floating valve core 300 can press the sealing ring 310, thereby completing the assembly.

[0052] In one embodiment, a waterproof gasket 120 (such as Figure 4 and Figure 5As shown in FIG. 1 ), a waterproof gasket 120 is disposed between the main body 100 and the battery pack housing 21 , and the waterproof gasket 120 is made of rubber.

[0053] In one embodiment, the main body 100 of the pressure relief vent valve 22 is connected by a bolt 130 (such as Figure 4 ) is mounted on the battery pack housing 21, and the pressure relief vent valve 22 is located below the battery pack housing 21 (as shown Figure 2 As shown). In this way, during the use of the battery energy storage module 20, dust is not easily accumulated on the exhaust window 101 of the pressure relief vent valve 22, and ventilation can be kept as unobstructed as possible.

[0054] In summary, the safety battery energy storage module 20 of the present invention can improve the sensitivity during pressure relief, ensure that the pressure relief breathable valve 22 works according to the settings, and improve the safety of the energy storage module; at the same time, it provides necessary protection for the waterproof breathable membrane 304 under extreme conditions to extend the working life of the pressure relief breathable valve 22.

[0055] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A safe battery energy storage module, characterized in that: It includes a battery pack shell and a pressure relief vent valve arranged on the battery pack shell; The pressure relief vent valve comprises: a main body, a valve body end cover, a floating valve core and a pressure limiting assembly, the main body is provided with a receiving cavity with two ends opened, a side wall of the main body is provided with an exhaust window, the valve body end cover is provided at one end of the main body, the floating valve core is accommodated in the receiving cavity, a reset elastic member is provided between the floating valve core and the valve body end cover; under the action of the reset elastic member, the edge of the floating valve core is pressed against the main body, and a sealing ring is provided between the floating valve core and the main body; The floating valve core is provided with an air hole and a pressing plate, the pressing plate is located at the air hole, a through hole corresponding to the air hole is opened on the pressing plate, and a waterproof and breathable membrane is provided between the pressing plate and the floating valve core; The floating valve core is provided with a hollow sleeve, the sleeve is aligned with the air vent, and the pressure limiting component is arranged in the sleeve; the pressure limiting component includes a shielding plate and a pressure limiting elastic member, the shielding plate can be movably accommodated in the sleeve, and the shielding plate is away from the compression plate of the floating valve core under the action of the pressure limiting elastic member.

2. The safe battery energy storage module according to claim 1, characterized in that: A blocking block and a cross beam are provided in the sleeve, and the pressure-limiting elastic member is a tension spring structure, and its two ends are respectively connected to the cross beam and the shielding piece; the shielding piece moves between the pressing plate and the blocking block, and under the action of the pressure-limiting elastic member, the shielding piece is pressed on the blocking block.

3. The safe battery energy storage module according to claim 2, characterized in that: The diameter of the air hole of the floating valve core is D1, the diameter of the through hole of the pressing plate is D2, the diameter of the shielding sheet is D3, and D2<D3<D1.

4. The safe battery energy storage module according to claim 1, characterized in that: The valve body end cover is provided with a guide column, the floating valve core is provided with a guide hole adapted to the guide column, and the guide column passes through the guide hole.

5. The safe battery energy storage module according to claim 4, characterized in that: The resetting elastic member is a cylindrical spring structure, the resetting elastic member is sleeved on the guide column, and the two ends of the resetting elastic member are respectively abutted against the valve body end cover and the floating valve core.

6. The safe battery energy storage module according to claim 1, characterized in that: The valve body end cover is connected to the main body via threads.

7. The safe battery energy storage module according to claim 1, characterized in that: The main body is provided with a waterproof gasket, the waterproof gasket is arranged between the main body and the battery pack shell, and the waterproof gasket is made of rubber.

8. The safe battery energy storage module according to claim 1, characterized in that: The main body of the pressure relief vent valve is mounted on the battery pack shell by bolts, and the pressure relief vent valve is located below the battery pack shell.

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