Battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery pack. The battery pack specifically comprises an exhaust plate, a bottom protection plate, a module frame and a plurality of single batteries stacked along a first direction, wherein a pressure release valve is arranged at the bottom of each single battery; a plurality of single batteries are placed on the exhaust plate, and pressure relief holes corresponding to the pressure relief valves are formed in the exhaust plate; the bottom protection plate covers the bottom wall of the exhaust plate, a pressure relief groove communicated with the pressure relief hole is formed in the bottom protection plate in a concave mode, and a pressure relief channel is defined by the pressure relief groove and the pressure relief hole; the module frame is arranged on the top wall of the bottom protection plate in a surrounding manner, so that a mounting space for accommodating the battery monomers is formed in the module frame, the module frame is of a hollow structure, and the pressure relief channel is arranged on the module frame in a communicating manner. According to the battery pack, high-temperature and high-pressure gas can be quickly exhausted when thermal runaway occurs to the single batteries, so that the safety of passengers is not influenced, and the use safety and reliability are improved.

Description

Technical Field

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

[0002] Lithium-ion batteries have the advantages of small volume, high energy density, long cycle life, and long storage time, and are widely used in some fields such as electronic devices, electric vehicles, and electric toys. With the rapid development of new energy vehicles and fierce industry competition, the thermal runaway problem of battery packs has attracted more and more attention. After thermal runaway occurs in the battery pack, a large amount of energy will be released in a short time, and this energy needs to be discharged outside the pack in time, otherwise it will further accelerate the thermal runaway and affect the safety of passengers.

[0003] In the existing battery pack design, the pressure relief valve and the positive and negative electrode tabs of the square battery cells used are usually on the same side, that is, both are located on the top cover plate of the battery cell. Therefore, when thermal runaway occurs in the square battery cell, the high-temperature flame ejected from the pressure relief valve of the battery cell usually ejects upward, posing a certain safety hazard to the safety of passengers; at the same time, some unburned electrolyte splashes out and contacts the busbar, wiring harness, copper busbar, etc., causing the battery pack to short-circuit and triggering a more serious secondary fire, thereby reducing the use safety and reliability of the battery pack.

[0004] Therefore, there is an urgent need to provide a new type of battery pack to solve the above technical problems in the prior art. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a battery pack, which can quickly discharge the high-temperature and high-pressure gas when the battery cell has a thermal runaway, without affecting the safety of passengers, and improves the use safety and reliability of the battery pack.

[0006] To achieve the above purpose, the utility model adopts the following technical solutions:

[0007] The battery pack specifically includes an exhaust plate, a bottom guard plate, a module frame, and a plurality of battery cells stacked along a first direction. A pressure relief valve is provided at the bottom of the battery cell; a plurality of the battery cells are placed on the exhaust plate, and the exhaust plate is provided with pressure relief holes corresponding to the pressure relief valves; the bottom guard plate covers the bottom wall of the exhaust plate, and the bottom guard plate is recessed with a pressure relief groove communicated with the pressure relief holes, and the pressure relief groove and the pressure relief holes enclose a pressure relief channel; the module frame surrounds the top wall of the bottom guard plate, so that the module frame forms an installation space for accommodating the battery cells. The module frame is a hollow structure, and the pressure relief channel is communicated with the module frame.

[0008] Optionally, limiting side plates are fixedly arranged at both ends of the exhaust plate along the first direction, a plurality of the battery cells are clamped between the two limiting side plates, and the limiting side plates are abutted against the inner wall of the module frame.

[0009] Optionally, exhaust holes are formed in the top wall of either end or both ends of the exhaust plate along the first direction, and the exhaust holes are communicated and arranged inside the module frame.

[0010] Optionally, the exhaust plate includes a main body portion and a side portion surrounding the bottom wall of the main body portion, a pressure relief hole and the exhaust hole are formed in the main body portion, and the side portion is cooperatively clamped in the pressure relief groove.

[0011] Optionally, the height of the side portion is equal to the depth of the pressure relief groove.

[0012] Optionally, the exhaust plate further includes a sealing portion, the sealing portion is abutted against the inner bottom wall of the pressure relief groove, and the main body portion, the sealing portion, the side portion and the pressure relief hole enclose the pressure relief channel.

[0013] Optionally, a plurality of the battery cells stacked along the first direction form a battery stack, a plurality of the battery stacks are arranged along the second direction, the plurality of battery stacks are arranged in the installation space, and both the exhaust plate and the pressure relief groove are provided with a plurality of them at intervals along the second direction corresponding to the battery stacks.

[0014] Optionally, a plurality of the battery stacks are further arranged along the first direction, and a partition plate is arranged between two adjacent battery stacks along the first direction.

[0015] Optionally, an explosion-proof valve is arranged on the outer wall of the module frame.

[0016] Optionally, the battery pack further includes a liquid cooling plate, the liquid cooling plate covers the top of the module frame, and the liquid cooling plate is in heat exchange connection with the battery cells.

[0017] Beneficial effects:

[0018] In the battery pack of the present utility model, the battery cells are provided with pressure relief valves at the bottom. When the battery cells are in thermal runaway, the flames, high-temperature gases, electrolytes, etc. generated inside are ejected downward through the bottom, avoiding affecting the safety of passengers above the battery cells. The battery cells are placed on the exhaust plate, and the bottom guard plate covers the bottom of the exhaust plate. The pressure relief grooves of the bottom guard plate are connected to the pressure relief holes of the exhaust plate and enclose a pressure relief channel. When the battery cells are in thermal runaway, the high-temperature gases and flames generated are discharged outward through the pressure relief channel. Moreover, the module frame is a hollow structure, which is connected to the pressure relief channel and can accommodate the high-temperature and high-pressure gases generated by thermal runaway, realizing the rapid discharge of thermal runaway gases, avoiding thermal diffusion caused by the high temperature generated when the battery cells are in thermal runaway, and improving the use safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is an axonometric view of the battery pack provided by the specific embodiment of the present utility model;

[0020] Figure 2 is an exploded view of the battery pack provided by the specific embodiment of the present utility model;

[0021] Figure 3 is a top view of the battery pack provided by the specific embodiment of the present utility model with the liquid cooling plate hidden;

[0022] Figure 4 is Figure 3 the sectional view at A-A in

[0023] Figure 5 is Figure 4 the partial enlarged view at B in

[0024] Figure 6 is an axonometric view of the exhaust plate and the bottom guard plate after being assembled together provided by the specific embodiment of the present utility model.

[0025] In the figure:

[0026] 100, battery cell; 101, battery stack; 110, pressure relief valve;

[0027] 200, exhaust plate; 201, pressure relief channel; 202, limiting side plate; 203, exhaust hole; 210, body part; 211, pressure relief hole; 220, side part; 230, sealing part;

[0028] 300, bottom guard plate; 310, pressure relief groove;

[0029] 400, module frame; 401, installation space; 410, explosion-proof valve; 420, partition;

[0030] 500, liquid cooling plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the convenience of description, only the parts related to the present utility model rather than all the structures are shown in the drawings.

[0032] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0033] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "above", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the first feature is at a higher horizontal height than the second feature. The first feature being "below", "below", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the first feature is at a lower horizontal height than the second feature.

[0034] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, 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, and thus cannot be understood as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0035] The first direction described in this embodiment is Figure 3 and Figure 4 the X direction shown in Figure 3 i.e., the thickness direction and the stacking arrangement direction of the battery cell 100; the second direction is

[0036] as Figures 1 to 5As shown in the figure, the battery pack specifically includes an exhaust plate 200, a bottom guard plate 300, a module frame 400, and a plurality of battery cells 100 stacked in the first direction. A pressure relief valve 110 is provided at the bottom of the battery cell 100; a plurality of the battery cells 100 are placed on the exhaust plate 200, and the exhaust plate 200 is provided with a pressure relief hole 211 corresponding to the pressure relief valve 110; the bottom guard plate 300 covers the bottom wall of the exhaust plate 200, and the bottom guard plate 300 is recessed with a pressure relief groove 310 communicating with the pressure relief hole 211. The pressure relief groove 310 and the pressure relief hole 211 enclose a pressure relief channel 201; the module frame 400 is disposed around the top wall of the bottom guard plate 300, so that the module frame 400 forms an installation space 401 for accommodating the battery cell 100. The module frame 400 is a hollow structure, and the pressure relief channel 201 is communicated with the module frame 400.

[0037] In the battery pack of this embodiment, the pressure relief valve 110 of the battery cell 100 is arranged at the bottom. When the battery cell 100 is in thermal runaway, the flame, high-temperature gas, electrolyte, etc. generated inside are ejected downward through the bottom, avoiding affecting the safety of passengers above the battery cell 100; and the battery cell 100 is placed on the exhaust plate 200, the bottom guard plate 300 covers the bottom of the exhaust plate 200, and the pressure relief groove 310 of the bottom guard plate 300 is communicated with the pressure relief hole 211 of the exhaust plate 200 and encloses a pressure relief channel 201. When the battery cell 100 is in thermal runaway, the high-temperature gas and flame generated are discharged outwards through the pressure relief channel 201, and the module frame 400 is a hollow structure, which is communicated with the pressure relief channel 201 and can accommodate the high-temperature and high-pressure gas generated by thermal runaway, realizing the rapid discharge of thermal runaway gas, avoiding thermal diffusion caused by the high temperature generated when the battery cell 100 is in thermal runaway, and improving the use safety of the battery pack.

[0038] As Figure 1 and Figure 2 As shown in the figure, an explosion-proof valve 410 is provided on the outer wall of the module frame 400. The explosion-proof valve 410 is used to timely discharge the high-temperature and high-pressure gas accumulated inside the module frame 400, avoiding the rupture of the module frame 400 caused by the continuous accumulation of high-pressure gas, and also avoiding the accumulated high-pressure gas affecting other battery cells 100 inside, further improving the use safety of the battery pack.

[0039] In this embodiment, the battery pack further includes a liquid cooling plate 500. The liquid cooling plate 500 covers the top of the module frame 400, and the liquid cooling plate 500 is heat exchange connected to the battery cell 100. The liquid cooling plate 500 is arranged on the top of the module frame 400. Using the principle that hot air rises and cold air descends, the heat generated by the battery cell 100 is conducted to the liquid cooling plate 500, and the liquid cooling plate 500 dissipates the heat, avoiding heat accumulation in the battery pack.

[0040] Please refer to Figure 3 and Figure 4 , multiple sets of the above-mentioned battery cells 100 stacked in the first direction form a battery stack 101. Multiple battery stacks 101 are arranged in the second direction. Multiple battery stacks 101 are arranged in the installation space 401. The exhaust plate 200 and the pressure relief groove 310 are each provided with a plurality of intervals corresponding to the battery stack 101 in the second direction. By arranging the exhaust plate 200 and the pressure relief groove 310 at intervals corresponding to the battery stack 101 in the second direction, it is possible to enable each battery stack 101 to exhaust and relieve pressure of the thermal runaway gas through its own pressure relief channel 201. The pressure relief of the battery stacks 101 arranged in the second direction does not affect each other, making the pressure relief and exhaust more smooth when a single battery cell 100 undergoes thermal runaway, and improving the use safety and reliability of the battery pack.

[0041] In this embodiment, a plurality of battery stacks 101 are also arranged in the first direction, and a partition plate 420 is arranged between two adjacent battery stacks 101 in the first direction. The arrangement of the partition plate 420 can prevent the length of a single battery stack 101 in the first direction from being too long, avoid excessive dimensional changes of the battery cells 100 inside the battery pack in the first direction due to cyclic use, thermal expansion and contraction, etc., and avoid squeezing and damaging the battery cells 100 at the central position. Using the partition plate 420 can effectively relieve and absorb the expansion size of the battery cells 100, and improve the use safety of the battery pack.

[0042] As Figure 2 and Figure 6 shown, further, limiting side plates 202 are fixedly arranged at both ends of the exhaust plate 200 in the first direction. A plurality of the battery cells 100 are clamped between the two limiting side plates 202, and the limiting side plates 202 abut against the inner wall of the module frame 400. The limiting side plates 202 can press a plurality of stacked battery cells 100, so that the exhaust plate 200 and the stacked battery cells 100 form a whole, which is convenient for assembling the battery cells 100 inside the module frame 400 and improves the installation efficiency.

[0043] Please refer to Figure 5 and Figure 6, an exhaust hole 203 is provided on the top wall at any one end or both ends of the above exhaust plate 200 along the above first direction, and the exhaust hole 203 is communicated and arranged inside the above module frame 400. In this embodiment, only one exhaust hole 203 is provided on the top wall of the exhaust plate 200, and this exhaust hole 203 is located at the bottom of the module frame 400 and is directly opposite to the through hole correspondingly provided on the module frame 400, so as to facilitate the smooth discharge of the thermal runaway gas in the pressure relief channel 201 into the module frame 400 and improve the pressure relief efficiency.

[0044] Furthermore, the above exhaust plate 200 includes a main body portion 210 and a side portion 220 surrounding the bottom wall of the main body portion 210. The above pressure relief hole 211 and the above exhaust hole 203 are provided on the main body portion 210, and the side portion 220 is fitted and clamped into the above pressure relief groove 310. It can be imagined that the main body portion 210 and the side portion 220 are integrally formed, so that the exhaust plate 200 is a square shell with an opening at the bottom, and the top wall of the square shell, that is, the main body portion 210, is provided with the above exhaust hole 203. The exhaust plate 200 arranged in this way can be better matched with the pressure relief groove 310, thereby improving the installation efficiency, and the pressure relief groove 310 can also be used to limit the exhaust plate 200 to prevent the exhaust plate 200 from loosening and improving the use reliability of the battery pack.

[0045] In this embodiment, the above exhaust plate 200 further includes a sealing portion 230, and the sealing portion 230 abuts against the inner bottom wall of the above pressure relief groove 310. The above main body portion 210, the above sealing portion 230, the above side portion 220 and the above pressure relief hole 211 enclose the above pressure relief channel 201. It should be noted that the sealing portion 230, the main body portion 210 and the side portion 220 are integrally formed, so that the exhaust plate 200 is formed into a shell with a cavity. The top wall of the exhaust plate 200 is provided with the above exhaust hole 203, and its internal cavity is the pressure relief channel 201. Such a setting can enable the exhaust plate 200 not to consider the seal between the exhaust plate 200 and the pressure relief groove 310 when installed in the pressure relief groove 310, thereby simplifying the installation process and reducing the production cost. It can also enable the pressure relief channel 201 to be directly connected to the module frame 400, reduce the connection gap, and prevent the thermal runaway gas from leaking, thereby improving the safety and reliability of the use of the battery pack.

[0046] As a preferred embodiment, the height of the above side portion 220 is equal to the groove depth of the above pressure relief groove 310. When the exhaust plate 200 is installed in the pressure relief groove 310 in this way, the top wall of the exhaust plate 200 can be flush with the top wall of the bottom protection plate 300, so that the battery cell 100 can be completely attached to the bottom protection plate 300, increasing the contact area between the bottom protection plate 300 and the exhaust plate 200 with respect to the battery cell 100, and thus improving the stability of the support.

[0047] In this embodiment, structural adhesive or thermally conductive structural adhesive is used for bonding and fixing between the exhaust plate 200 and the bottom guard plate 300, between the limit side plates 202 and the module frame 400, and between the bottom of the battery cell 100 and the bottom guard plate 300, which can improve the overall package mode of the battery pack and enhance the fixing effect, and will not be elaborated here.

[0048] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. Battery pack, characterized in that, Including: A plurality of battery cells stacked in a first direction, and a pressure relief valve is provided at the bottom of the battery cell; An exhaust plate on which a plurality of the battery cells are placed, and the exhaust plate is provided with pressure relief holes corresponding to the pressure relief valves; A bottom guard plate covering the bottom wall of the exhaust plate, the bottom guard plate is recessed with a pressure relief groove communicating with the pressure relief hole, and the pressure relief groove and the pressure relief hole enclose a pressure relief passage; A module frame surrounding the top wall of the bottom guard plate, so that the module frame forms an installation space for accommodating the battery cells, the module frame is a hollow structure, and the pressure relief passage is communicated with the module frame; 2. The battery pack according to claim 1, characterized in that, Limiting side plates are fixedly arranged at both ends of the exhaust plate along the first direction, and a plurality of the battery cells are clamped between the two limiting side plates, and the limiting side plates are abutted against the inner wall of the module frame; 3. The battery pack according to claim 2, wherein, An exhaust hole is opened on the top wall of any one end or both ends of the exhaust plate along the first direction, and the exhaust hole is communicated with the inside of the module frame; 4. The battery pack according to claim 3, characterized in that, The exhaust plate includes a main body part and a side part surrounding the bottom wall of the main body part, the main body part is provided with the pressure relief hole and the exhaust hole, and the side part is cooperatively clamped in the pressure relief groove; 5. The battery pack according to claim 4, wherein The height of the side part is equal to the depth of the pressure relief groove; 6. The battery pack according to claim 5, wherein, The exhaust plate further includes a sealing part, the sealing part abuts against the inner bottom wall of the pressure relief groove, and the main body part, the sealing part, the side part and the pressure relief hole enclose the pressure relief passage; 7. The battery pack according to claim 1, wherein The plurality of battery cells stacked in the first direction form a battery stack, a plurality of the battery stacks are arranged in a second direction, and the plurality of battery stacks are arranged in the installation space, and the exhaust plate and the pressure relief groove are both provided with a plurality of corresponding battery stacks at intervals along the second direction; 8. The battery pack according to claim 7, wherein, A plurality of the battery stacks are also arranged in the first direction, and a partition is arranged between two adjacent battery stacks along the first direction; 9. The battery pack according to any one of claims 1-8, characterized in that, An explosion-proof valve is arranged on the outer wall of the module frame; 10. The battery pack according to any one of claims 1-8, characterized in that, The battery pack further includes a liquid cooling plate covering the top of the module frame, and the liquid cooling plate is in heat exchange connection with the battery cell.

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