Power battery module and battery pack

Abstract

The utility model discloses a power battery module. The power battery module comprises a plastic bracket, the sealing cover plate covers the plastic support, the plastic support is matched with the sealing cover plate to form a pressure relief cavity, and a pressure relief protection layer made of heat insulation materials is formed on the inner cavity wall of the pressure relief cavity. Meanwhile, the utility model further discloses a battery pack applying the power battery module, and the problem that an existing pressure relief cavity is prone to damage and failure due to thermal shock of high-temperature and high-pressure jets is solved.

Description

Technical Field

[0001] The utility model relates to the field of batteries, and in particular to a power battery module and a battery pack. Background Art

[0002] Power batteries are storage batteries that provide power for electric vehicles, electric trains and other tools. Power batteries are the core components of new energy vehicles and an important direction for future energy transformation.

[0003] For example, in the battery pack and power device with authorization announcement number CN220341374U developed by the inventor and published on January 12, 2024, the battery pack comprises a pressure relief chamber formed by the battery cell holder, the second part of the box body, and the inner wall thereof, and the pressure relief chamber is connected to the outside world, and a barrier film is provided on the side of the battery cell holder facing the second part of the box body to block the foam glue so that there is no foam glue in the pressure relief chamber. By providing a barrier film on the side of the battery cell holder facing the second part of the box body, the foam glue can be prevented from entering the pressure relief chamber under the action of gravity. In this way, when thermal runaway occurs in the battery cell, the high-temperature and high-pressure jet is released from the battery cell explosion-proof valve at the bottom of the battery cell. The pressure of the high-temperature and high-pressure jet acting on the foam glue and the barrier membrane in the exhaust hole is greater than the compressive strength of the barrier membrane and the colloid in the exhaust hole, so as to break the barrier membrane and the foam glue in the exhaust hole. The battery cell explosion-proof valve opens, and the high-temperature and high-pressure jet passes through the exhaust hole, enters the pressure relief chamber, and is finally discharged to the outside of the battery pack through the box explosion-proof valve connected to the pressure relief chamber.

[0004] However, since the depth of the pressure relief chamber along the central axis of the battery cell is not very large, the high-temperature and high-pressure jet will inevitably produce thermal shock after entering the pressure relief chamber, causing damage to the pressure relief chamber, thereby making the pressure relief function of the pressure relief chamber and the function of guiding the discharge of the jet invalid. Utility Model Content

[0005] In order to overcome at least one of the defects of the prior art described above, the utility model provides a power battery module and a battery pack, which solves the problem that the existing pressure relief chamber is easily damaged and failed due to thermal shock of high-temperature and high-pressure ejecta.

[0006] The technical solution adopted by the utility model to solve the problem is:

[0007] A power battery module, comprising:

[0008] Plastic bracket;

[0009] A sealing cover plate is provided on the plastic support, and the plastic support cooperates with the sealing cover plate to form a pressure relief chamber, and an inner cavity wall of the pressure relief chamber is formed with a pressure relief protective layer made of a heat insulating material.

[0010] In some embodiments of the present utility model, the pressure relief protection layer includes a cover plate protection layer, and the cover plate protection layer is disposed on the sealing cover plate.

[0011] In some embodiments of the present utility model, the pressure relief protection layer further includes a bracket protection layer, and the bracket protection layer is disposed on the plastic bracket.

[0012] In some embodiments of the present utility model, the pressure relief protection layer further includes a transition protection layer, and two opposite sides of the transition protection layer are respectively connected to the cover plate protection layer and the bracket protection layer.

[0013] In some embodiments of the present utility model, one of the plastic bracket and the sealing cover plate is provided with a snap projection, and the other of the plastic bracket and the sealing cover plate is provided with a snap groove, and the snap projection is snapped into the snap groove.

[0014] In some embodiments of the present utility model, a sealing connection member is disposed between the snap projection and the snap groove, and the sealing connection member extends along the groove length direction of the snap groove.

[0015] In some embodiments of the present utility model, the power battery module further includes a foaming colloid and a plurality of cell unit components connected in series and parallel to each other. The foaming colloid wraps the circumferential side of the cell unit component and the cell explosion-proof valve of the cell unit component, and each cell unit component is disposed on the plastic bracket, and an exhaust hole or a weak part is disposed on the plastic bracket opposite to the cell explosion-proof valve.

[0016] In some embodiments of the present utility model, the power battery module further includes a pressure relief connecting pipe, and the inside of the pressure relief chamber is communicated with the outside of the pressure relief chamber through the pressure relief connecting pipe.

[0017] In some embodiments of the present utility model, a plurality of the cell unit components are connected to form a battery pack. The sealing cover plates are disposed on both sides of the battery pack, and each plastic bracket is provided with an exhaust hole or a weak part opposite to the cell explosion-proof valve.

[0018] The present utility model also discloses a battery pack including the above-mentioned power battery module.

[0019] In summary, a power battery module and a battery pack provided by the present utility model have the following technical effects:

[0020] The pressure relief protection layer is skillfully formed in the pressure relief chamber, thereby effectively protecting the plastic bracket and the sealing cover plate from damage caused by the thermal shock of high pressure, ensuring the effectiveness of the pressure relief chamber, and thus stably discharging the high-temperature and high-pressure ejecta from the power battery module, effectively reducing the risk of thermal propagation in the power battery module, and solving the problem that the existing pressure relief chamber is easily damaged and fails due to the thermal shock of the high-temperature and high-pressure ejecta. At the same time, since the plastic bracket and the sealing cover plate are covered and arranged, it helps to form a pressure relief protection layer on the inner side wall of the pressure relief chamber, reducing the processing difficulty and cost. Brief Description of the Drawings

[0021] Figure 1 It is an overall exploded view of a power battery module of the present invention;

[0022] Figure 2 It is a partial exploded view of a power battery module of the present invention;

[0023] Figure 3 It is an assembled top view of a power battery module of the present invention;

[0024] Figure 4 is Figure 2 a cross-sectional view taken along line A-A in

[0025] Figure 5 is Figure 3 a partially enlarged view at B in

[0026] Figure 6 is Figure 3 a partially enlarged view at C in

[0027] Reference numerals: 1 - plastic bracket, 11 - exhaust hole, 12 - inner side surface of the bracket, 13 - outer side surface of the bracket, 14 - peripheral side surface of the bracket, 2 - sealing cover plate, 21 - inner side surface of the cover plate, 22 - outer side surface of the cover plate, 23 - peripheral side surface of the cover plate, 3 - pressure relief chamber, 4 - pressure relief protection layer, 41 - cover protection layer, 42 - bracket protection layer, 43 - transition protection layer, 5 - buckle protrusion, 6 - sealing connection member, 7 - foaming colloid, 8 - battery cell component, 9 - pressure relief connecting pipe. Detailed Embodiments

[0028] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present utility model belongs. The terms used in the description of the present utility model herein are only for the purpose of describing specific embodiments and are not intended to limit the present utility model.

[0031] Specifically, in combination with Figures 1 to 5 As shown, the present utility model discloses a power battery module, which includes a plastic bracket 1, a sealing cover plate 2, and a plurality of cell unit components 8 connected in series and parallel with each other. The shape and size of the sealing cover plate 2 are adapted to those of the plastic bracket 1. Among them, the sealing cover plate 2 has a relatively arranged inner cover surface 21, an outer cover surface 22, and a peripheral cover surface 23. The two opposite sides of the peripheral cover surface 23 are respectively connected to the inner cover surface 21 and the outer cover surface 22.

[0032] Furthermore, the plastic bracket 1 has an inner bracket surface 12, an outer bracket surface 13, and a peripheral bracket surface 14. The inner bracket surface 12 and the outer bracket surface 13 are relatively arranged. The two opposite sides of the peripheral bracket surface 14 are respectively connected to the inner bracket surface 12 and the outer bracket surface 13. The outer bracket surface 13 is the side of the plastic bracket 1 for approaching the cell unit component 8. The sealing cover plate 2 is covered on the plastic bracket 1. The inner bracket surface 12 of the plastic bracket 1 and the inner cover surface 21 of the sealing cover plate 2 cooperate to enclose a pressure relief chamber 3. Then, the vertical distance between the inner bracket surface 12 and the inner cover surface 21 is the depth dimension of the pressure relief chamber 3.

[0033] In this embodiment, a pressure relief protection layer 4 made of a heat insulation material is formed on the inner cavity wall of the pressure relief chamber 3. The heat insulation material here can be preferably mica material with high temperature resistance properties, and the pressure relief protection layer 4 is preferably formed by spraying. Of course, it can be alternatively connected by clamping or bonding. In this way, when the high-temperature and high-pressure ejecta is ejected into the interior of the pressure relief chamber 3, it will impact on the pressure relief protection layer 4, so that the high-temperature and high-pressure ejecta generated when the cell unit component 8 is in a thermal runaway state will not directly impact on the pressure relief chamber wall, blocking a large amount of heat and impact force from damaging the plastic bracket 1 and / or the sealing cover plate 2, reducing the risk of failure of the plastic bracket 1 and / or the sealing cover plate 2, and ensuring that the high-temperature and high-pressure substances can be discharged under the guidance of the pressure relief chamber 3 and away from the battery module / battery pack.

[0034] As a preferred embodiment of this embodiment, specifically, please refer to Figures 1 to 5 As shown, the pressure relief protective layer 4 includes a cover protective layer 41, and the cover protective layer 41 is disposed on the sealing cover 2. Specifically, the cover protective layer 41 is disposed on the inner side surface 21 of the cover of the sealing cover 2, and the cover protective layer 41 covers each battery cell component 8 at least in the direction of the orthographic projection. When any battery cell component 8 undergoes thermal runaway, it will be able to ensure that the high-temperature and high-pressure ejecta released by the battery cell component 8 impacts on the inner side surface 21 of the cover.

[0035] As a further preferred embodiment of this embodiment, specifically, please refer to Figures 1 to 5 As shown, the pressure relief protective layer 4 further includes a bracket protective layer 42, and the bracket protective layer 42 is disposed on the plastic bracket 1. Specifically, the bracket protective layer 42 is disposed on the inner side surface 12 of the bracket of the plastic bracket 1, and the bracket protective layer 42 covers each battery cell component 8 at least in the direction of the orthographic projection. Of course, the bracket protective layer 42 preferably covers the entire inner side surface 12 of the bracket.

[0036] In this way, when the high-temperature and high-pressure substance impacts on the cover protective layer 41 and rebounds towards the plastic bracket 1, under the action of the bracket protective layer 42, the high-temperature and high-pressure substance will not directly generate a thermal impact on the plastic bracket 1, protecting the plastic bracket 1 from damage.

[0037] It should be noted that the power battery module further includes a foaming colloid 7. The foaming colloid 7 belongs to polyurethane or silicone-based glue, and no specific limitation is made here. The foaming colloid 7 wraps the periphery of the battery cell component 8 and the battery cell explosion-proof valve of the battery cell component 8, and each battery cell component 8 is disposed on the plastic bracket 1. The plastic bracket 1 is provided with exhaust holes 11 or weak parts that are arranged in alignment with the battery cell explosion-proof valves.

[0038] Preferably, the foaming colloid 7 can be poured into the battery box of the battery pack, and then the battery pack formed by connecting several battery cell components 8 is placed in the battery box, so that each battery cell component 8 of the battery pack is completely wrapped by the foaming colloid 7. Not only does the foaming colloid 7 have good flame retardancy and heat insulation ability, which can avoid the transfer of heat, substances, flames, etc. from any battery cell component 8 after thermal runaway to the adjacent battery cell components 8, but also there is no need to set glue injection holes on the battery box, which can solve the problems of designing a glue flow groove at the bottom of the battery cell component 8 and additionally opening holes in the CCS component caused by the existing process of pouring and sealing the foaming colloid 7 from the side or top.

[0039] In addition, the foam colloid 7 is filled between the plastic support 1 and the battery cell unit 8 to seal the assembly gap between the plastic support 1 and the battery cell unit 8 and cover the battery cell explosion-proof valve of the battery cell unit 8 to avoid the problem of the battery cell explosion-proof valve being exposed. The unexpected effect is that, under the support of the support protection layer 42, the foam colloid 7 can be prevented from falling into the pressure relief chamber 3 from the exhaust hole 11 or the weak point under the action of gravity.

[0040] When the battery cell unit 8 has thermal runaway, the battery cell unit 8 squeezes and breaks through the foam colloid 7 and the support protective layer 42 near the battery cell explosion-proof valve, so that the high-temperature and high-pressure ejection is released from the battery cell explosion-proof valve of the battery cell unit 8 and enters the pressure relief chamber 3. The support protective layer 42 seals and blocks the exhaust holes 11 or weak parts corresponding to other battery cell units 8, thereby protecting the battery cell units 8 adjacent to or close to the thermal runaway battery cell units from being affected by the high-temperature and high-pressure ejection.

[0041] As a further preferred method of this embodiment, please refer to Figures 1 to 5 As shown, the pressure relief protection layer 4 further includes a transition protection layer 43 , and two opposite sides of the transition protection layer 43 are respectively connected to the cover plate protection layer 41 and the bracket protection layer 42 .

[0042] Specifically, the transition protection layer 43 may be optionally provided on the plastic support 1, the transition protection layer 43 may also be optionally provided on the sealing cover plate 2, or the transition protection layer 43 may be optionally provided on both the plastic support 1 and the sealing cover plate 2. In this way, through the cooperation of the cover plate protection layer 41, the cover plate protection layer 41 and the transition protection layer 43, during the process of the high-temperature and high-pressure ejection being transmitted and flowing along the extension direction of the pressure relief chamber 3, a large amount of heat attached to the ejection can be fully blocked by the pressure relief protection layer 4, reducing the risk of the plastic support 1 and the sealing cover plate 2 being deformed or melted by heat, thereby well ensuring the effectiveness of the plastic support 1 and the sealing cover plate 2 during use.

[0043] Furthermore, the power battery module also includes a pressure relief connecting pipe 9, and the interior of the pressure relief chamber 3 is connected to the outside of the pressure relief chamber 3 through the pressure relief connecting pipe 9, so that the high-temperature and high-pressure jet flowing inside the pressure relief wall can be discharged into the pressure relief chamber 3, that is, the high-temperature and high-pressure jet can be guided away from the power battery module to avoid a large amount of heat affecting the function and state of the battery pack.

[0044] As a preferred method of this embodiment, please refer to Figure 1 , Figure 2 , Figure 4 as well as Figure 6As shown, a buckle projection 5 is provided on the plastic bracket 1. The buckle projection 5 extends along the circumferential direction of the inner side surface 12 of the plastic bracket 1. A buckle groove corresponding to the buckle projection 5 is provided on the sealing cover plate 2, and the buckle projection 5 is snapped into the buckle groove. In this way, not only the purpose of detachable connection between the plastic bracket 1 and the sealing cover plate 2 is achieved, ensuring the formation of the pressure relief protection layer 4 inside the pressure relief chamber 3, but also the processing difficulty and process cost of forming the pressure relief protection layer 4 are reduced. At the same time, the effect of rapid positioning and stable installation during the assembly process of the plastic bracket 1 and the sealing cover plate 2 is also achieved.

[0045] In other embodiments, it is also optional that a buckle projection 5 is provided on the sealing cover plate 2, and a buckle groove corresponding to the buckle projection 5 is provided on the plastic bracket 1, and the buckle projection 5 is snapped into the buckle groove.

[0046] As a preferred manner of this embodiment, specifically in combination with Figure 1 , Figure 2 , Figure 4 and Figure 6 As shown, a sealing connector 6 is arranged between the buckle projection 5 and the buckle groove. The sealing connector 6 extends along the groove length direction of the buckle groove, thereby sealing the assembly gap between the buckle projection 5 and the buckle groove, and improving the sealing performance of the pressure relief chamber 3.

[0047] It should be noted that the above-mentioned sealing cover plate 2 can be made of plastic or metal material. The above-mentioned cell unit 8 is preferably a cylindrical battery. Of course, it can also be a square battery. Taking the cell unit 8 as a cylindrical battery as an example, the cell unit 8 has a cell positive end and a cell negative end arranged oppositely. The cell explosion-proof valve of the cell unit 8 can be located near the cell positive end of the cell unit 8. In other designs, the cell explosion-proof valve of the cell unit 8 can also be located at the cell negative end of the cell unit 8.

[0048] It should also be noted that if several cell units 8 in the battery pack are arranged along the short side direction of the plastic bracket 1 to form a battery row module of the battery pack, then several cell units 8 in the battery pack are arranged along the long side direction of the plastic bracket 1 as the array direction of the battery row module. Among them, the cell positive ends of each cell unit 8 in the battery row module are all on the same side, and the cell positive ends of the cell units 8 in adjacent two battery row modules are preferably arranged staggeredly.

[0049] As a preferred manner of this embodiment, specifically according to Figure 1 As shown, plastic brackets 1 are provided on both sides of the battery pack, and each plastic bracket 1 is provided with a sealing cover plate 2, so pressure relief chambers 3 are formed on both sides of the battery pack. In addition, each plastic bracket 1 is provided with an exhaust hole 11 or a weak part arranged opposite to the cell explosion-proof valve.

[0050] With such a setting, regardless of whether the explosion-proof valve of the battery cell of the battery cell unit 8 is provided near the positive electrode end of the battery cell of the battery cell unit 8 or the explosion-proof valve of the battery cell of the battery cell unit 8 is provided at the negative electrode end of the battery cell of the battery cell unit 8. Regardless of whether the positive electrode ends of the battery cell units 8 of two adjacent battery row modules are staggered or the positive electrode ends of the battery cell units 8 of two adjacent battery row modules are arranged side by side, in the event of thermal runaway of any battery unit component, the high-temperature and high-pressure ejecta can be released into the pressure relief chamber 3, improving the flexibility of battery design. At the same time, a pressure relief protective layer 4 is formed in the pressure relief chamber 3, so that the high-temperature and high-pressure ejecta can be stably guided and discharged outside the pressure relief chamber 3, effectively improving the use safety and use stability of the battery module.

[0051] Based on the structure and connection relationship of the above power battery module, the inventor also provides a battery pack, which includes the above power battery module.

[0052] The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A power battery module, characterized in that, Comprising: A plastic bracket (1); A sealing cover plate (2), the sealing cover plate (2) is covered on the plastic bracket (1), and a pressure relief chamber (3) is formed by the cooperation of the plastic bracket (1) and the sealing cover plate (2), and a pressure relief protection layer (4) made of heat insulation material is formed on the inner cavity wall of the pressure relief chamber (3).

2. The power battery module according to claim 1, wherein: The pressure relief protection layer (4) includes a cover plate protection layer (41), and the cover plate protection layer (41) is arranged on the sealing cover plate (2).

3. The power battery module according to claim 2, wherein: The pressure relief protection layer (4) further includes a bracket protection layer (42), and the bracket protection layer (42) is arranged on the plastic bracket (1).

4. The power battery module according to claim 3, wherein: The pressure relief protection layer (4) further includes a transition protection layer (43), and two opposite sides of the transition protection layer (43) are respectively connected to the cover plate protection layer (41) and the bracket protection layer (42).

5. The power battery module according to any one of claims 1 to 4, characterized in that: One of the plastic bracket (1) and the sealing cover plate (2) is provided with a snap protrusion (5), and the other of the plastic bracket (1) and the sealing cover plate (2) is provided with a snap groove, and the snap protrusion (5) is snapped into the snap groove.

6. The power battery module according to claim 5, wherein: A sealing connecting piece (6) is arranged between the snap protrusion (5) and the snap groove, and the sealing connecting piece (6) extends along the groove length direction of the snap groove.

7. The power battery module according to claim 1, characterized in that: It further includes a foaming colloid (7) and a plurality of battery cell components (8) connected in series and parallel with each other. The foaming colloid (7) wraps the periphery of the battery cell components (8) and the battery cell explosion-proof valves of the battery cell components (8), and each battery cell component (8) is arranged on the plastic bracket (1), and an exhaust hole (11) or a weak part is arranged on the plastic bracket (1) corresponding to the battery cell explosion-proof valve.

8. The power battery module according to claim 7, wherein: It further includes a pressure relief connecting pipe (9), and the inside of the pressure relief chamber (3) is communicated with the outside of the pressure relief chamber (3) through the pressure relief connecting pipe (9).

9. The power battery module according to claim 7 or 8, wherein: A plurality of the battery cell components (8) are connected to form a battery pack. The plastic brackets (1) are arranged on both sides of the battery pack, and each plastic bracket (1) is provided with the sealing cover plate (2), and an exhaust hole (11) or a weak part is arranged on each plastic bracket (1) corresponding to the battery cell explosion-proof valve.

10. A battery pack, characterized in that, Comprising the power battery module according to any one of claims 1 to 9.

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