Battery module assembly, battery pack, and vehicle

Abstract

Embodiments of the present disclosure provide a battery module assembly, a battery pack, and a vehicle. The battery module assembly comprises battery cells and first liquid cooling plates; each battery cell is provided with poles and an explosion-proof valve located on the same end surface in the height direction of the battery cell; the first liquid cooling plates are attached to the upper portions of the poles in the height direction of the battery cells; the projections of the first liquid cooling plates and the explosion-proof valves in the height direction of the battery cells do not overlap; and at least part of the first liquid cooling plates are located in a spraying range of the explosion-proof valves. The battery module assembly of the present disclosure uses a cooling medium released by the first liquid cooling plates to cool a thermally runaway battery cell, and can prevent the first liquid cooling plates from interfering with the opening of the explosion-proof valves and ejection of a high-temperature substance, thereby effectively suppressing heat spreading.

Description

Battery module assembly, battery pack and vehicle

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202410903507.1 and application date of July 5, 2024, and the Chinese patent application with application number 202311677004.9 and application date of December 7, 2023, and claims the priority of the Chinese patent application. The entire contents of the Chinese patent application are hereby introduced into this application as a reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a battery module assembly, a battery pack, and a vehicle. Background Art

[0004] Lithium-ion batteries have become the mainstream power battery for vehicles in the current new energy industry. They offer advantages such as high energy density and long cycle life. However, when power batteries experience over-discharge, overcharge, overheating, or other internal quality issues, there is a risk of thermal runaway.

[0005] In related technologies, a spray device is generally provided directly above the explosion-proof valve. When thermal runaway occurs in the battery cell, the explosion-proof valve will spray high-temperature substances toward the spray device. The spray device melts through and releases cooling medium into the interior of the explosion-proof valve to cool the battery cell, thereby suppressing the heat spread from the runaway battery cell to the adjacent battery cells.

[0006] However, installing a spray device directly above the explosion-proof valve will hinder the opening and exhaust of the explosion-proof valve, and cause the ejected material to accumulate between the battery cell and the spray device. This will not only affect the cooling effect of the cooling medium released by the spray device on the battery cell, but also cause the internal pressure of the battery cell to increase, and there is a risk of failure of the battery cell structure. Summary of the Invention

[0007] In order to solve the above technical problems, the embodiments of the present disclosure provide a battery module assembly, a battery pack and a vehicle.

[0008] In a first aspect, an embodiment of the present disclosure provides a battery module assembly, comprising:

[0009] A battery cell having a pole and an explosion-proof valve located on the same end face in a height direction of the battery cell;

[0010] a first liquid cooling plate, the first liquid cooling plate being attached above the pole along a height direction of the battery cell;

[0011] The projections of the first liquid cooling plate and the explosion-proof valve along the height direction of the battery core do not overlap, and at least a portion of the first liquid cooling plate is located within the spraying range of the explosion-proof valve.

[0012] In some embodiments, the first liquid cooling plate has a weak area, and the weak area is located within the spray range of the explosion-proof valve;

[0013] And / or, the first liquid cooling plate is made of a composite material.

[0014] In some embodiments, a first offset distance is provided between the projection of the first liquid cooling plate and the explosion-proof valve along the height direction of the battery cell, and the first offset distance is 0 to 30 mm;

[0015] And / or, the first liquid cooling plate and the explosion-proof valve have a second offset distance in a height direction of the battery cell, and the second offset distance is 0 to 20 mm;

[0016] And / or, the melting point of the meltable portion of the first liquid cooling plate is less than or equal to 400°C.

[0017] In some embodiments, the wall thickness of the meltable portion of the first liquid cooling plate is 0.1 mm to 2 mm; and / or

[0018] The thermal conductivity of the first liquid cooling plate is greater than or equal to 0.5 W / m·K.

[0019] In some embodiments, there are multiple battery cells, and the multiple battery cells are arranged in an array to form a battery module. The battery module includes at least one battery pack arranged along a first direction. The first liquid cooling plate extends along the first direction, and the length of the first liquid cooling plate in the first direction is greater than or equal to the length of the battery pack in the first direction.

[0020] Wherein, the first direction is perpendicular to the height direction of the battery cell.

[0021] In some embodiments, the first direction is the length direction of the battery cell, two first liquid cooling plates are attached above one of the poles, the two first liquid cooling plates are spaced apart along the width direction of the battery cell, and the explosion-proof valve is located between the two first liquid cooling plates;

[0022] Alternatively, the first direction is the width direction of the battery cell, and a first liquid cooling plate is attached above one of the poles.

[0023] In some embodiments, a bar is further included, wherein the bar is connected to the pole, and the first liquid cooling plate is attached to the bar.

[0024] In some embodiments, the first liquid cooling plate is connected to the pole via a heat conducting layer.

[0025] In some embodiments, a second liquid cooling plate is further included, wherein the second liquid cooling plate is arranged in contact with the battery cell, and the second liquid cooling plate and the first liquid cooling plate are arranged opposite to each other in the height direction of the battery cell.

[0026] In a second aspect, an embodiment of the present disclosure provides a battery module assembly, comprising:

[0027] There are multiple battery cells arranged along a first direction, and there are multiple bar sheets, each of which is connected to the poles of two adjacent battery cells to form a bar sheet row; the first liquid cooling plate extends along the first direction, and the first liquid cooling plate is attached to the bar sheet row along a second direction perpendicular to the first direction.

[0028] In some embodiments, the first liquid cooling plate includes a connected liquid cooling portion and an overlapping edge, the liquid cooling portion is attached to the bar array, and the overlapping edge is attached to the shoulder of the battery cell.

[0029] In some embodiments, the tab is welded, screwed, riveted, or bonded to the pole of the battery module with conductive adhesive.

[0030] In some embodiments, in a third direction perpendicular to the first direction and the second direction, a ratio between a length L1 of the electrode and a length L3 of the battery module is 0.1-0.4.

[0031] In some embodiments, in the first direction, a ratio between a width L2 of the electrode and a width L4 of the battery module is 0.1-0.99.

[0032] In some embodiments, in a third direction perpendicular to the first direction and the second direction, a ratio of the length of the tab to the length L1 of the pole is 0.1-5.

[0033] In some embodiments, in a third direction perpendicular to the first direction and the second direction, a ratio of the length of the liquid cooling portion to the length of the bar is 0.1-2.

[0034] In some embodiments, the battery module assembly further includes a second liquid cooling plate, which is configured to be disposed on the battery module, and the second liquid cooling plate is disposed opposite to the first liquid cooling plate.

[0035] In some embodiments, a first cooling channel is provided in the first liquid cooling plate, a second cooling channel is provided in the second liquid cooling plate, and each of the first cooling channel and the second cooling channel has a cooling medium for cooling the battery module.

[0036] In some embodiments, the battery module assembly further includes a liquid inlet pipe and a liquid outlet pipe, and the liquid inlet pipe, the first liquid cooling plate, the liquid outlet pipe and the second liquid cooling plate are connected in sequence.

[0037] In some embodiments, the second liquid cooling plate has a heat exchange panel and a flow channel panel arranged opposite to each other along the first direction, the heat exchange panel and the flow channel panel form the second cooling flow channel, the area of ​​the heat exchange panel and the contact area of ​​the battery module is S1, the area of ​​the battery module connected to the heat exchange panel is S2, and the ratio of S1 to S2 is 0.1-1.

[0038] In some embodiments, in the first direction, the thickness of the heat exchange panel is D1, the size of the second cooling channel is H1, 0.02≤D1 / H1≤5; the thickness of the channel panel is D2, the size of the second cooling channel is H1, 0.02≤D2 / H1≤5;

[0039] In some embodiments, in the first direction, the thickness of the side of the first liquid cooling plate connected to the bar is D3, the size of the second cooling channel is H2, and 0.02≤D3 / H2≤2.

[0040] In some embodiments, the battery module assembly further includes a heat conductive layer between the first liquid cooling plate and the bar.

[0041] In a third aspect, an embodiment of the present disclosure provides a battery pack comprising the battery module assembly as described above.

[0042] In some embodiments, the battery pack further includes a shell, and the battery module assembly is disposed within the shell.

[0043] In a fourth aspect, an embodiment of the present disclosure provides a vehicle, comprising the battery module assembly as described above, or the battery pack as described above.

[0044] The technical solution provided by the embodiments of the present disclosure has the following advantages over the prior art:

[0045] By adopting the battery cell module assembly provided by the first aspect of the embodiment of the present disclosure, the first liquid cooling plate is arranged on the pole of the battery cell, and the projections of the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell are not overlapped, that is, they are completely offset, so as to fully utilize the space in the height direction of the battery cell, and reasonably plan the relative positions of the first liquid cooling plate and the explosion-proof valve of the battery cell. When the battery cell has thermal runaway, the high-temperature material inside the battery cell can be ejected from the explosion-proof valve and melt through the part of the first liquid cooling plate that is within the spraying range of the explosion-proof valve, so that the cooling medium in the first liquid cooling plate can be sprayed toward the explosion-proof valve and the surrounding area, and then the cooling medium that enters the runaway battery cell through the explosion-proof valve is used to cool the inside of the runaway battery cell. The first liquid cooling plate of the embodiment of the present disclosure can also reduce Less interference with the opening of the explosion-proof valve and the ejection of high-temperature substances, avoiding the risk of increased internal pressure of the battery cell and failure of the battery cell structure due to the accumulation of high-temperature substances near the explosion-proof valve, making it easier for the cooling medium released by the first liquid cooling plate to flow into the runaway battery cell, and having a better cooling effect on the runaway battery cell, thereby suppressing heat spread. In addition, the heat generated by the battery cell can be transferred to the first liquid cooling plate through the pole and dissipated promptly and quickly through the cooling medium in the first liquid cooling plate, thereby improving the overall cooling capacity of the battery module assembly by the first liquid cooling plate, preventing the risk of thermal runaway of the battery cell caused by local excessive temperature due to heat accumulation near the pole, which is suitable for fast-charging batteries, thereby helping to improve the fast-charging capability and safety of the battery module assembly.

[0046] By adopting the battery cell module assembly provided by the second aspect of the embodiment of the present disclosure, a first liquid cooling plate is set on the bar connected to the pole, so that the heat generated on the pole can be directly dissipated promptly and quickly through the first liquid cooling plate, thereby improving the overall cooling capacity of the liquid cooling assembly for the battery module, preventing heat from accumulating near the pole and causing the risk of thermal runaway of the battery cell due to local excessive temperature. It is suitable for fast-charging batteries, which is beneficial to improving the fast-charging capability and safety of use of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0048] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without inventive work, including:

[0049] FIG1 is a perspective view of a battery module assembly according to an embodiment of the present disclosure.

[0050] FIG2 is a perspective view of a battery module according to an embodiment of the present disclosure.

[0051] FIG3 is a front view of a battery module assembly according to an embodiment of the present disclosure.

[0052] FIG. 4 is a perspective view of a battery pack according to an embodiment of the present disclosure.

[0053] FIG5 is a three-dimensional diagram of the battery module and the tab assembly according to an embodiment of the present disclosure.

[0054] FIG6 is a front view of a battery module assembly according to another embodiment of the present disclosure.

[0055] FIG. 7 is a perspective view of a battery module assembly according to another embodiment of the present disclosure.

[0056] FIG8 is a perspective view of a battery cell according to an embodiment of the present disclosure.

[0057] FIG9 is a front view of a battery module assembly according to another embodiment of the present disclosure.

[0058] FIG10 is a perspective view of the cooperation between the first liquid cooling plate and the second liquid cooling plate according to an embodiment of the present disclosure.

[0059] FIG. 11 is a perspective view of a first liquid cooling plate according to an embodiment of the present disclosure.

[0060] FIG. 12 is a perspective view of a second liquid cooling plate according to an embodiment of the present disclosure.

[0061] FIG13 is a cross-sectional view of a second liquid cooling plate according to an embodiment of the present disclosure.

[0062] FIG14 is a cross-sectional view of a first liquid cooling plate according to an embodiment of the present disclosure.

[0063] FIG. 15 is a perspective view of another battery module according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0064] The following describes embodiments of the present disclosure in more detail with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure.

[0065] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc. mentioned in this disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0066] It should be noted that the modifications of "one" and "multiple" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, they should be understood as "one or more".

[0067] To address the problem of existing vehicle thermal management systems failing to collect sufficient heat from the refrigerant in low or extremely low temperature environments, and thus failing to fully activate the compressor to generate heat, the disclosed embodiments provide a new thermal management system. This new thermal management system enriches the heat of the coolant flowing out of the battery heat exchanger, achieving sufficient vaporization of the refrigerant and ensuring the amount of vaporized refrigerant, thereby enabling the compressor to fully compress and generate heat.

[0068] In the related art, a spray device is generally set on the top of the explosion-proof valve, and the projections of the spray device and the explosion-proof valve in the height direction of the battery cell are overlapped. When the battery cell suffers thermal runaway, the leakage port of the spray device is opened by active opening or passive melting through, thereby releasing the cooling medium in the spray device to the explosion-proof valve of the runaway battery cell, cooling the runaway battery cell and the adjacent battery cells, thereby suppressing the heat spread process from the runaway battery cell to the adjacent battery cells.

[0069] However, the solutions in the related art have the following defects:

[0070] 1. The spray device is facing the explosion-proof valve of the out-of-control battery cell. When the distance between the spray device and the explosion-proof valve in the height direction of the battery cell is ≤8mm, the spray device will affect the exhaust space of the explosion-proof valve of the battery cell, thereby causing the ejected high-temperature material to accumulate between the spray device and the explosion-proof valve of the battery cell. The internal pressure of the battery cell increases, and the battery cell structure has a greater risk of failure. In addition, the cooling medium sprayed by the spray device cannot enter the interior of the battery cell, resulting in poor cooling effect.

[0071] 2. The spray device is facing the explosion-proof valve of the out-of-control battery cell. When the distance between the spray device and the explosion-proof valve in the height direction of the battery cell is ≤5mm, the spray device will hinder the opening of the explosion-proof valve.

[0072] 3. If the above two defects are avoided through reasonable distance design, the distance between the spray device and the battery cell explosion-proof valve in the height direction of the battery cell will be too large (greater than 8mm), which will greatly reduce the spatial integration efficiency of the battery pack.

[0073] The inventors discovered that staggering the projections of the spray device and the explosion-proof valve in the height direction of the battery cell can solve the above three problems and defects. However, since the explosion-proof valve sprays high-temperature substances along the height direction of the battery cell, when the projections of the spray device and the explosion-proof valve in the height direction of the battery cell are staggered, the first liquid cooling plate may not be directly touched by the high-temperature substance, and thus cannot be melted through. This potential problem has not been effectively solved in the relevant technology.

[0074] It is generally believed in the industry that arranging the spray device and the explosion-proof valve opposite each other in the height direction of the battery cell can ensure that the spray device can be melted through, and subjectively believes that when the projections of the spray device and the explosion-proof valve in the height direction of the battery cell do not overlap, the spray device cannot be guaranteed to be melted through. As a result, the solution of staggering the projections of the spray device and the explosion-proof valve in the height direction of the battery cell has been ignored, and no further research has been conducted on the staggered arrangement solution.

[0075] In response to the inventor's findings and subjective biases within the industry, the inventor conducted further research. By testing the positional relationship between the explosion-proof valve and the first liquid cooling plate, the inventor confirmed the broad spray range of the explosion-proof valve during thermal runaway of the battery cell. The area where the high-temperature material actually passes and the area where the high-temperature material can effectively melt through at least part of the first spray device through thermal radiation, heat conduction, thermal convection, etc. are all determined as the spray range of the explosion-proof valve. When at least part of the spray device is arranged within the spray range, it can be ensured that the high-temperature material sprayed from the explosion-proof valve can melt through part of the spray device through the combined action of one or more of direct contact, thermal radiation, heat conduction, thermal convection, etc.

[0076] Based on the above research findings, the spray device and the explosion-proof valve are staggered in the height direction of the battery cell, and at least part of the spray device is arranged within the spray range of the explosion-proof valve. When a battery cell suffers from thermal runaway, the spray device can be melted through by the high-temperature material sprayed by the explosion-proof valve, causing the cooling medium in the spray device to leak from the melted-through position to the vicinity of the runaway battery cell. Since there is no accumulation of high-temperature material at the explosion-proof valve, the cooling medium can more easily enter the battery cell, thereby achieving a better effect of cooling the runaway battery cell and its adjacent battery cells, and can more effectively suppress the progress of thermal runaway.

[0077] The inventors also discovered that in order to improve the thermal management performance of the battery in the related art, a cooling device is set on the surface of the pole and its tab, and the heat generated by the pole and its tab is quickly discharged through the circulation of the cooling medium to achieve cooling of the battery cell. When the battery cell has thermal runaway, the cooling device can also quickly take away the heat of the thermal runaway of the battery cell, thereby cooling the runaway battery cell and the adjacent battery cell. However, the cooling device on the surface of the battery cell pole and its tab is made of metal material (such as aluminum alloy, etc.). When thermal runaway occurs, the cooling device can only transfer heat to the battery cell through heat conduction, and high-temperature materials cannot melt through the cooling device. When the coolant water pump does not work, such as when the vehicle's 12V power supply is damaged or the water pump is damaged after a collision, the heat cannot be taken away by the coolant circulation, and the spread of the thermal runaway of the battery cell cannot be effectively suppressed.

[0078] Based on the problems and defects existing in the cooling device in the related art, the inventor conducted research and found that after attaching the spray device to the pole, under normal operating conditions, the spray device can perform thermal management of the battery cell pole, adjust the battery cell temperature, and improve the thermal management performance of the battery cell. The spray device thus has the advantages of spraying cooling medium to suppress heat spread when the battery cell thermal runaways and the advantage of improving the thermal management performance of the battery cell under normal operating conditions.

[0079] The following describes a battery module assembly 100, a battery pack 1000, and a vehicle according to an embodiment of the present disclosure with reference to Figures 1 to 15.

[0080] As shown in Figures 1 to 3, the battery module assembly 100 according to an embodiment of the present disclosure includes a battery cell 11 and a first liquid cooling plate 3. The battery cell 11 has a pole 111 and an explosion-proof valve 113 located on the same end face in the height direction of the battery cell 11. The first liquid cooling plate 3 is attached above the pole 111 along the height direction of the battery cell 11. The projections of the first liquid cooling plate 3 and the explosion-proof valve 113 along the height direction of the battery cell 11 do not overlap, and at least a portion of the first liquid cooling plate 3 is located within the spray range of the explosion-proof valve 113.

[0081] It should be understood that the pole 111 and the explosion-proof valve 113 are integrated on the same end face of the battery cell 11, and the first liquid cooling plate is connected to the pole, so as to facilitate the reasonable layout of the relative position relationship of the pole 111, the first liquid cooling plate 3 and the explosion-proof valve 113, so that the first liquid cooling plate 3 can not only suppress the process of thermal runaway of the battery cell 11 when thermal runaway occurs, but also cool the pole 111 under normal operating conditions, thereby improving the thermal management performance of the battery cell.

[0082] When the battery cell 11 experiences thermal runaway due to over-discharge, over-charge, over-temperature, or other internal quality problems, the high-temperature material inside the battery cell 11 will break through the explosion-proof valve 113 and erupt. The high-temperature material will melt through the part of the first liquid cooling plate 3 located in the spray range of the explosion-proof valve 113 in a short period of time. The cooling medium in the first liquid cooling plate 3 will be sprayed toward the vicinity of the explosion-proof valve 113 and into the interior of the battery cell 11, thereby reducing the temperature of the battery cell 11 and suppressing the spread of heat.

[0083] In the embodiment of the present disclosure, since the projections of the first liquid cooling plate 3 and the explosion-proof valve 113 in the height direction of the battery cell 11 do not overlap, there will be no interference with the spray path of the ejected high-temperature material, thereby preventing the high-temperature material from changing the spray direction after being blocked, causing the adjacent battery cell 11 to be directly impacted by the high-temperature material. It can also prevent the high-temperature material from accumulating between the battery cell 11 and the first liquid cooling plate 3, causing the cooling medium to be unable to flow into the battery cell 11. The arrangement position of the first liquid cooling plate 3 and the explosion-proof valve 113 in the embodiment of the present disclosure can enable the high-temperature material to be ejected in time, and release the pressure inside the battery cell 11, and also facilitate the cooling medium to flow into the battery cell 11 to achieve cooling, thereby improving the cooling effect.

[0084] The spraying range of the explosion-proof valve 113 in the embodiment of the present disclosure includes but is not limited to the area where the high-temperature material actually passes, and the area where the high-temperature material can effectively melt through at least part of the first liquid cooling plate 3 through heat radiation, heat conduction, heat convection, etc.

[0085] For example, when thermal runaway occurs in the battery cell 11, the explosion-proof valve 113 opens, and the high-temperature material ejected from the explosion-proof valve 113 will be approximately in the shape of an inverted cone. At this time, the approximately inverted cone-shaped area that the high-temperature material actually passes through is the injection range of the explosion-proof valve 113. At the same time, the heat radiation area close to the inverted cone area and capable of reaching a temperature that can melt through the first liquid cooling plate 3 is also the injection range of the explosion-proof valve 113.

[0086] Although the projections of the first liquid cooling plate 3 and the explosion-proof valve 113 in the height direction of the battery cell 11 do not overlap, a portion of the first liquid cooling plate 3 close to the explosion-proof valve 113 is within the spray range. The portion of the first liquid cooling plate 3 within the spray range can be melted through, and the cooling medium in the first liquid cooling plate 3 will flow to the first weak area 113 and then enter the interior of the out-of-control battery cell 11.

[0087] In the embodiment of the present disclosure, the first liquid cooling plate 3 has a width dimension, and at least a portion of the first liquid cooling plate 3 is located within the spray range of the explosion-proof valve 113. This should be understood as meaning that part or all of the first liquid cooling plate 3 in its own width direction (i.e., the length direction shown in FIG1 ) is located within the spray range of the explosion-proof valve 113. For example, as shown in FIG1 , portion A within the dotted line range shown in FIG1 is the portion of the first liquid cooling plate 3 located within the spray range of the explosion-proof valve 113. For another example, as shown in FIG1 , by changing the position of the first liquid cooling plate 3 in the length direction shown in FIG1 , the size of portion A within the dotted line range can be adjusted, thereby adjusting the size of the portion of the first liquid cooling plate 3 located within the spray range of the explosion-proof valve 113. For another example, the width dimension of the first liquid cooling plate 3 is relatively small, and the entire portion of the first liquid cooling plate 3 in its own width direction is located within the spray range of the explosion-proof valve 113.

[0088] In the embodiments of the present disclosure, the length direction shown in the drawings is the length direction of the battery cell, the width direction is the width direction of the battery cell, and the height direction is the height direction of the battery cell.

[0089] In addition, the portion A shown in FIG. 1 may be an approximately fan-shaped region, or the portion A may be an approximately rectangular region.

[0090] As shown in FIG1 , first liquid cooling plates 3 are provided on both poles 111 of the battery cell 11 , and each first liquid cooling plate 3 has a portion located within the spraying range of the explosion-proof valve 113 .

[0091] In addition, the cooling medium sprayed out after the first liquid cooling plate 3 is melted through can form a spray area centered on the explosion-proof valve 113, which not only performs targeted cooling of the explosion-proof valve 113 of the out-of-control battery cell 11, but also can form an effective enveloping spray on the surrounding area of ​​the explosion-proof valve 113. Part of the cooling medium can also enter the interior of the battery cell 11 through the explosion-proof valve 113, cool the interior of the battery cell, and improve the effect of suppressing heat spread.

[0092] When thermal runaway occurs in the battery cell 11, the high-temperature material inside the battery cell 11 can be ejected from the explosion-proof valve 113 and melt through the portion of the first liquid cooling plate 3 located within the spraying range of the explosion-proof valve 113, so that the cooling medium released by the first liquid cooling plate 3 can be sprayed toward the explosion-proof valve 113 and the surrounding area, and the cooling medium enters the runaway battery cell 11 through the explosion-proof valve 113 to cool the inside of the runaway battery cell 11; the embodiment of the present disclosure arranges the first liquid cooling plate 3 on the pole 111 of the battery cell 11 and makes The projections of the first liquid cooling plate 3 and the explosion-proof valve 113 of the battery cell 11 on the same end face do not overlap, that is, they are completely offset from each other, so as to fully utilize the space in the height direction of the battery cell 11. The relative positions of the first liquid cooling plate 3 and the explosion-proof valve 113 of the battery cell 11 are rationally planned to avoid interference with the opening of the explosion-proof valve 113 and the ejection of high-temperature substances. This allows the cooling medium released by the first liquid cooling plate 3 to flow more easily into the interior of the runaway battery cell 11, thereby achieving a better cooling effect on the runaway battery cell 11 and suppressing heat spread.

[0093] The battery module assembly of the embodiment of the present disclosure can directly dissipate the heat generated on the pole through the first liquid cooling plate connected to the pole in a timely and rapid manner, thereby improving the overall cooling capacity of the battery module assembly, preventing heat from accumulating near the pole and causing the risk of thermal runaway of the battery cell due to local excessive temperature. It is suitable for fast-charging batteries, which is beneficial to improving the fast-charging capability and safety of the battery module.

[0094] The cooling device in the related art cannot be directly used as the first liquid cooling plate in the embodiment of the present disclosure for the following reasons:

[0095] 1. The cooling device on the surface of the battery cell pole and its bar is made of metal materials (such as aluminum alloy, etc.). When the battery cell is thermally runaway, it is difficult to be melted through, so the cooling medium cannot be sprayed toward the explosion-proof valve, and the process of heat spread cannot be effectively suppressed.

[0096] 2. The cooling device on the surface of the battery cell pole and its tab is made of non-metallic materials (such as nylon, etc.). When the position relationship between the cooling device and the explosion-proof valve is set unreasonably (for example, there is a long distance between the projection of the cooling device and the explosion-proof valve in the height direction of the battery cell), or the material model is set unreasonably (such as the melting point is too high or thermosetting material is used), the function of cooling the battery cell by leakage of the cooling medium cannot be achieved.

[0097] Based on this, in the embodiment of the present disclosure, a weak area is provided for the first liquid cooling plate 3 which is difficult to be melted through, or the material of the first liquid cooling plate 3 is changed to solve the above defects and problems.

[0098] In some embodiments, the first liquid cooling plate 3 has a weak area, and the weak area is located within the spraying range of the explosion-proof valve 113 .

[0099] It should be understood that when the battery cell 11 thermally runs away, the explosion-proof valve 113 will spray out high-temperature substances, and the weak area is located within the spraying range of the explosion-proof valve 113, thereby ensuring that the weak area is melted through, and the cooling medium in the first liquid cooling plate 3 is sprayed toward the explosion-proof valve 113, so that the cooling medium can enter the battery cell through the explosion-proof valve 113.

[0100] Specifically, the weak area of ​​the first liquid cooling plate 3 is determined according to the relative position of the first liquid cooling plate 3 and the explosion-proof valve 113 to ensure that the weak area is within the high-temperature material spraying range of the explosion-proof valve 113 when the battery cell 11 thermally runs away. At the same time, in order to enable the weak area to melt through in time and spray the cooling medium toward the explosion-proof valve 113, the structure, wall thickness, etc. of the weak area can be designed, and the overall wall thickness and material parameters of the first liquid cooling plate 3 can also be designed. The spatial position relationship between the first liquid cooling plate 3 and the explosion-proof valve 113 can also be further constrained.

[0101] When the first liquid cooling plate 3 is made of metal, since the first liquid cooling plate 3 has a certain thickness, if a weak zone is not set, the high-temperature material sprayed from the explosion-proof valve 113 is not easy to quickly melt through the first liquid cooling plate 3 made of metal. By setting the portion of the first liquid cooling plate 3 within the spraying range as a weak zone, the shell thickness of the weak zone of the first liquid cooling plate 3 is less than the shell thickness of other areas of the first liquid cooling plate 3, which can ensure that the portion of the first liquid cooling plate 3 within the spraying range is melted through in time, thereby cooling the out-of-control battery cell 11.

[0102] Optionally, as shown in FIG1 , the portion A within the dotted line range is a weak area, the weak area and the explosion-proof valve are arranged opposite to each other in the length direction of the battery cell, and the wall thickness of the weak area is smaller than the wall thickness of the shell of other areas of the first liquid cooling plate 3 .

[0103] Optionally, the first liquid cooling plate 3 shown in FIG1 extends along the width direction of the battery cell, and the entire length of the first liquid cooling plate 3 on one side close to the explosion-proof valve in the length direction of the battery cell is set as a weak area, and the wall thickness of the weak area is thinner than that of other parts.

[0104] Optionally, the weak area is a plurality of weak points arranged in part A within the dotted line range shown in Figure 1, and the wall thickness of the plurality of weak points is less than the wall thickness of the shell of other areas of the first liquid cooling plate 3. For example, 2, 3 or 5 countersunk holes are arranged in the part A area within the dotted line range shown in Figure 1. The countersunk holes do not penetrate the shell of the first liquid cooling plate 3, but the wall thickness of the bottom of the countersunk holes is thinner than the shell wall thickness at other positions and is more easily melted through.

[0105] For example, the material of the first liquid cooling plate 3 is aluminum alloy, and the wall thickness of the first liquid cooling plate 3 within the spray range is 0.1mm to 2mm. Specifically, the wall thickness of the weak area of ​​the first liquid cooling plate 3 can be 0.1mm, 0.25mm, 0.45mm or 2mm, and the wall thickness of the shell of other areas of the first liquid cooling plate 3 is greater than 2mm. Specifically, the wall thickness of the shell of other areas of the first liquid cooling plate 3 can be 2.5mm, 3mm, 3.5mm, etc., which can not only ensure the overall structural strength of the first liquid cooling plate 3 and prevent the first liquid cooling plate 3 from being deformed or broken after a collision, but also ensure that the weak area can be melted through in time when thermal runaway occurs in the battery cell 11, and the cooling medium can be released.

[0106] In some embodiments, the first liquid cooling plate 3 is made of a composite material. Specifically, a thermoplastic composite material can be used. For example, the first liquid cooling plate 3 is made of a composite material including PPA (polyphthalamide) or a composite material including PPO (polystyrene). When the battery cell 11 experiences thermal runaway, the first liquid cooling plate 3 can be melted through in a timely manner and a cooling medium can be sprayed toward the runaway battery cell 11.

[0107] In addition, the first liquid cooling plate 3 is made of a composite material as a whole, which has a stable melting point and a relatively low melting point. When the melting point is less than or equal to 400°C, when the battery cell thermally runs away, the part of the first liquid cooling plate 3 within the spray range can be melted through in time. Therefore, a weak area does not need to be set, that is, at this time, there is no need to reduce the wall thickness of the part of the first liquid cooling plate 3 within the spray range.

[0108] For example, the material of the first liquid cooling plate 3 is a composite material including PPA, and the shell thickness of the first liquid cooling plate 3 can be 1mm, 1.3mm, 1.6mm or 2mm. There is no weak area on the first liquid cooling plate 3, that is, the wall thickness of the first liquid cooling plate is the same throughout. When thermal runaway occurs in the battery cell, the high-temperature material ejected from the explosion-proof valve can directly melt through the part within the injection range, meeting the performance requirements. At this time, not setting a weak area can reduce the difficulty and cost of the manufacturing process.

[0109] For another example, relative to the previous example, when the melting point of the composite material used to make the first liquid cooling plate 3 becomes higher, or when the wall thickness of the first liquid cooling plate 3 made of the composite material is greater than 2 mm, in order to avoid the high-temperature material sprayed from the explosion-proof valve from failing to melt through the part of the first liquid cooling plate 3 within the spraying range in time when thermal runaway occurs in the battery cell, at this time, it is necessary to set a weak area within the part of the first liquid cooling plate 3 within the spraying range.

[0110] In the solution of the related art where the spray device is directly opposite the explosion-proof valve, when the distance between the spray device and the explosion-proof valve in the height direction of the battery cell is ≤8mm, it will affect the exhaust space of the explosion-proof valve. When the distance between the spray device and the explosion-proof valve in the height direction of the battery cell is ≤5mm, the spray device will further hinder the opening of the explosion-proof valve. Although this defect in the related art can be circumvented by reasonably designing the distance between the spray device and the explosion-proof valve, if the distance between the spray device and the explosion-proof valve in the height direction of the battery cell is too large (greater than 8mm), it will significantly reduce the spatial integration efficiency of the battery pack.

[0111] In the scheme of the first liquid cooling plate and the explosion-proof valve being completely offset in the embodiment of the present disclosure, in order to avoid the unreasonable design of the spatial position relationship between the first liquid cooling plate and the explosion-proof valve, which is specifically reflected in the distance D between the projections of the first liquid cooling plate and the explosion-proof valve along the height direction of the battery cell (i.e., the first offset distance), and the distance H between the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell (the second offset distance), when the distance D and the distance H are too large, it is easy to cause the high-temperature material ejected by the explosion-proof valve to be unable to melt through the first liquid cooling plate, or it takes a long time to melt through the first liquid cooling plate, thereby resulting in poor suppression effect of heat spread and being unfavorable for cooling the out-of-control battery cell. A distance H that is too large will also lead to low space utilization in the height direction of the battery cell (wasted on the gap between the first liquid cooling plate and the battery cell), and it is impossible to use more space to increase the battery power.

[0112] Therefore, the embodiment of the present disclosure conducted a simulation test on the distance between the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell, optimized the distance between the projections of the first liquid cooling plate and the explosion-proof valve along the height direction of the battery cell (i.e., the first offset distance) D, and the distance between the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell (the second offset distance) H, and reasonably determined them to be: the first offset distance D is 0 to 30 mm, and the second offset distance H is 0 to 20 mm.

[0113] Regarding the second offset distance H, any value within the range of 0 to 20 mm enables the first liquid cooling plate 3 to simultaneously utilize the advantages of spraying cooling medium to suppress heat spread during thermal runaway of the battery cells and the advantages of improving the thermal management performance of the battery cells under normal operating conditions, without compromising the advantages of suppressing heat spread and improving the thermal management performance of the battery cells. Furthermore, when the installation space for arranging the battery cells is not limited, the battery power level meets the requirements, and there is no need to deliberately compress the space to increase the power level, the second offset distance H can be any value between 0 and 20 mm. When the installation space for battery cells in some vehicle models is limited and it is necessary to increase the battery power level through more reasonable vehicle space planning or to reserve space for the layout of other components, the second offset distance H can be reduced, for example, to any value between 0 and 10 mm. In this case, more space can be saved for increasing the battery power level or arranging other components, which is more practical in actual applications.

[0114] As shown in FIG3 , in some embodiments, there is a first offset distance between the projection of the first liquid cooling plate 3 and the explosion-proof valve 113 in the height direction of the battery cell 11 , and the first offset distance is 0 to 30 mm.

[0115] It should be noted that the projections of the first liquid cooling plate 3 and the explosion-proof valve 113 in the height direction of the battery cell 11 are completely offset from each other, and the first offset distance is the distance D shown in FIG. 3 .

[0116] The offset distance between the projection of the first liquid cooling plate 3 on the first end surface and the projection of the explosion-proof valve 113 in the height direction of the battery cell 11 can be determined according to the spray angle range of the high-temperature material and the temperature radiation range of the high-temperature material when the battery cell 11 thermally runs away.

[0117] Because the high-temperature material ejected from the explosion-proof valve 113 of the battery cell 11 is ejected roughly along the height of the battery cell 11, in a nearly inverted cone shape, if the projections of the first liquid cooling plate 3 and the explosion-proof valve 113 of the battery cell 11 in the height direction are completely offset, and the offset is too large, the first liquid cooling plate 3 cannot be directly reached by the high-temperature material, resulting in a weak area that cannot be melted through. To address this potential problem, by studying the positional relationship between the explosion-proof valve 11 of the battery cell 11 and the first liquid cooling plate 3, a range of first offset distance D was determined, allowing the high-temperature material ejected from the runaway battery cell 11 to melt through the first liquid cooling plate 3 through thermal radiation, thermal conduction, and thermal convection. Test results show that the first offset distance between the first liquid cooling plate 3 and the explosion-proof valve 113 of the battery cell 11 can meet the requirements within a range of 0 to 30 mm.

[0118] In addition, when the projections of the first liquid cooling plate 3 and the explosion-proof valve 113 in the height direction of the battery cell 11 partially overlap, it is easy to cause the melt-through gap on the first liquid cooling plate 3 to be too large, resulting in the spraying area being not concentrated, the spraying liquid losing too quickly, and even causing the first liquid cooling plate 3 to be disconnected as a whole, which will also interfere with the high-temperature substance, affecting the spraying of the cooling medium in the first liquid cooling plate 3, and the high-temperature substance in the battery cell 11 to accumulate between the first liquid cooling plate 3 and the battery cell 11.

[0119] When the first offset distance is too large, for example, the first offset distance is 40 mm, 50 mm or 63 mm, the melt-through gap on the first liquid cooling plate 3 will be smaller or cannot be melted through, which may easily lead to the first liquid cooling plate 3 not being melted through in a timely and effective manner, or the melting speed of the first liquid cooling plate 3 will be relatively slow, and spraying cannot be performed in time, and heat spread cannot be effectively suppressed.

[0120] Specifically, the first offset distance D can be 0, 8 mm, 20 mm, or 30 mm. When the first offset distance D gradually increases from 0 to 30 mm, under the condition that the spray range of the explosion-proof valve 113 is constant, the portion of the first liquid cooling plate 3 within the spray range of the explosion-proof valve 113 gradually decreases. When D is 0 mm, a relatively large melting area can be ensured on the first liquid cooling plate 3, and the spray flow rate is relatively larger. At this time, the portion of the first liquid cooling plate 3 within the spray range of the explosion-proof valve 113 is more likely to be melted through after direct contact with the high-temperature material; when D is 30 mm, the portion of the first liquid cooling plate 3 within the spray range of the explosion-proof valve 113 is more likely to be melted through by means of thermal radiation, heat conduction, heat convection, etc. of the high-temperature material. There is a larger space between the first liquid cooling plate 3 and the explosion-proof valve 113, which facilitates the release of the high-temperature material inside the battery cell and reduces the internal pressure of the battery cell. When D is 20 mm, after the portion of the first liquid cooling plate 3 within the spray range of the explosion-proof valve 113 is melted through, it has a better spray angle, so that the cooling medium can be sprayed in an approximately fan-shaped manner to the explosion-proof valve 113 in an enveloping manner, while also allowing sufficient release space between the first liquid cooling plate 3 and the explosion-proof valve 113; when D is 8 mm, the cooling medium sprayed after the first liquid cooling plate 3 is melted through has a better spray flow and spray angle, and the spray effect is better.

[0121] Furthermore, as shown in Figure 3, the value of the first offset distance D is 8 mm. While ensuring that the first liquid cooling plate 3 and the explosion-proof valve 113 are completely offset in the height direction of the battery cell and do not affect the opening of the explosion-proof valve 113 and the injection of high-temperature substances, the first liquid cooling plate 3 completely covers the pole 111 in the height direction of the battery cell 11, and can be better attached to the pole, effectively cool the pole, and meet the requirements of the thermal management performance of the battery under fast charging conditions.

[0122] As shown in FIG3 , in some embodiments, the first liquid cooling plate 3 and the explosion-proof valve 113 have a second offset distance in the height direction of the battery cell 11 , and the second offset distance is 0 to 20 mm.

[0123] It should be understood that there is a spacing distance (ie, a second offset distance) between the first liquid cooling plate 3 and the explosion-proof valve 113 in the height direction of the battery cell 11 , and the second offset distance is the distance H shown in FIG. 3 .

[0124] When the distance between the first liquid cooling plate 3 and the explosion-proof valve 113 in the height direction of the battery cell 11 is too large, for example, the second offset distance is 25 mm, 36.5 mm or 40 mm, the battery module assembly 100 will be too large in the height direction of the battery cell 11, the occupied space will increase, the space of the entire vehicle will not be utilized, and the battery charge capacity will be affected.

[0125] The second offset distance H can be 0, 6.7mm, 13mm or 20mm. Under the premise that the structural dimensions of the battery cell itself remain unchanged, when the second offset distance H is 0mm, the cooling medium sprayed after the first liquid cooling plate 3 is melted through is more likely to flow along the end surface of the battery cell 11 toward the explosion-proof valve, thereby more easily entering the interior of the battery cell. When the second offset distance H is 20mm, there is sufficient space for high-temperature material release above the explosion-proof valve 113, which is more conducive to reducing the pressure inside the battery cell. When the second offset distance H is 13mm, while ensuring a more reasonable space for high-temperature material release above the explosion-proof valve 113, the size of the battery module assembly in the height direction of the battery cell can be reduced. Under the premise of sufficient installation space, more space can be used to increase the power of the battery cell 11. When the second offset distance H is 6.7mm, the size of the battery module assembly in the height direction of the battery cell can be further reduced, the power density of the battery can be improved, the integration of the battery module assembly can be higher, and the spraying effect of the cooling medium can also be better.

[0126] Furthermore, the distance between the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell (the second offset distance) depends on the pole height + the thickness of the electrical connection bar + the thickness of the thermal conductive adhesive. For example, the pole height is generally 3.2mm (square shell battery cell), the thickness of the electrical connection bar is generally (1.5 to 2mm), and the thickness of the thermal conductive adhesive is (0.5 to 1.5mm). Therefore, the distance between the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell is 5.2mm to 6.7mm. When the bar and / or thermal conductive adhesive is not provided, the distance between the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell can be further reduced. Compared with the related art where the spray device is directly opposite the explosion-proof valve, the distance between the spray device and the explosion-proof valve in the height direction of the battery cell is ≥8mm, which can save more than 1.3mm of space and can use more space to improve the power density of the battery.

[0127] In the structure of the above embodiment, not only the installation position of the first liquid cooling plate 3 and the relative position of the first liquid cooling plate 3 and the explosion-proof valve 113 are limited, ensuring that the occupied space volume of the battery module assembly 100 can meet the requirements of the installation position and optimize the overall spatial layout, but also the first liquid cooling plate 3 can more accurately spray the high-temperature material injection area and the surrounding area when melting through, thereby improving the cooling effect and effectively preventing heat spread.

[0128] In the related art, when the spray device is facing the explosion-proof valve of the out-of-control battery cell 11, when the distance between the spray device and the explosion-proof valve of the battery cell 11 in the height direction of the battery cell 11 is close, it will not only cause the spray device to hinder the opening of the explosion-proof valve of the battery cell 11, but also cause the spray device to affect the exhaust space of the explosion-proof valve of the battery cell 11, thereby causing high-temperature materials to accumulate between the spray device and the battery cell 11, the pressure inside the battery cell 11 package to increase, and there is a risk of failure of the battery cell 11 structure.

[0129] Although the above problem can be avoided to a certain extent by increasing the distance between the spray device and the explosion-proof valve in the height direction of the battery cell 11, it will cause the spray device to be at a greater distance from the explosion-proof valve of the battery cell 11, greatly reducing the spatial integration efficiency of the battery pack 1000.

[0130] On the contrary, in the embodiment of the present disclosure, by designing the spatial position between the first liquid cooling plate 3 and the explosion-proof valve 113, the size limitation of the first liquid cooling plate 3 in the height direction of the battery cell 11 is greatly reduced, and the spatial position between the first liquid cooling plate 3 and the explosion-proof valve 113 can be more flexibly adjusted according to the spatial layout of the entire vehicle.

[0131] In order to further improve the performance of the first liquid cooling plate during thermal runaway of the battery cell and under normal operating conditions, the present disclosure further designs and constrains the material, melting point, wall thickness, etc. of the first liquid cooling plate, thereby ensuring that the first liquid cooling plate in the present disclosure has the advantage of spraying cooling medium to suppress the spread of heat from the runaway battery cell, and also has the advantage of cooling the battery cell poles to improve the thermal management performance of the battery.

[0132] Specifically, this disclosure defines the following characteristics of the first liquid cooling plate: a. Use of thermoplastic material (PPA, PPO, etc.); b. Melting point ≤ 400°C; c. Wall thickness ≤ 2mm; d. Thermal conductivity ≥ 0.5W / m·K. The following describes each of the characteristics of the first liquid cooling plate 3 in further detail with reference to specific embodiments.

[0133] In some embodiments, the melting point of the meltable portion of the first liquid cooling plate 3 is less than or equal to 400°C.

[0134] Specifically, the melting point of the meltable portion of the first liquid cooling plate 3 of the embodiment of the present disclosure is less than or equal to 400°C. The melting point of the meltable portion of the first liquid cooling plate 3 of the embodiment of the present disclosure can be 400°C, 310°C or 220°C, and at the same time, the melting point of the first liquid cooling plate 3 must be greater than the operating temperature of the battery under normal operation. When the melting point of the first liquid cooling plate 3 is 220°C, when the battery cell 11 experiences thermal runaway, it can be melted through more quickly. The fast melting speed can suppress the heat spread of the battery cell by spraying the cooling medium earlier. When the melting point of the first liquid cooling plate 3 is 400°C, the deformation of the first liquid cooling plate 3 can be reduced, and the first liquid cooling plate 3 can be prevented from further deformation due to heat radiation, heat conduction, heat convection, etc. after melting through, which affects the structural stability of the first liquid cooling plate 3. When the melting point of the first liquid cooling plate 3 is 210°C, while ensuring that the first liquid cooling plate 3 is melted through in time, the stability of the first liquid cooling plate 3 in a high temperature environment can also be improved.

[0135] In the embodiment of the present disclosure, the meltable portion of the first liquid cooling plate 3 may be only the portion within the spraying range, or the entire first liquid cooling plate 3 may be melted through. In this case, the melting point of the entire first liquid cooling plate 3 is less than or equal to 400°C.

[0136] When a battery cell 11 experiences thermal runaway, the ejected high-temperature material can melt through the first liquid cooling plate 3 in a very short time, allowing the cooling medium to flow out from the melt-through location and spray down the runaway battery cell 11. During the cooling process, the cooling medium is sprayed directly onto the surface or inside the battery cell 11, absorbing heat and evaporating, thereby lowering the temperature of the battery cell 11 and the surrounding environment.

[0137] For example, the melting point of the portion of the first liquid cooling plate 3 within the spraying range is 220°C. When the battery cell 11 experiences thermal runaway, the temperature of the high-temperature substance sprayed out by the explosion-proof valve 113 can reach about 500°C. The portion of the first liquid cooling plate 3 within the spraying range will not only be melted through when in contact with the high-temperature substance, but also be able to melt through the first liquid cooling plate 3 before the high-temperature substance contacts the first liquid cooling plate 3 through thermal radiation of the high-temperature substance, and the first liquid cooling plate 3 can release the cooling medium in advance, so that the cooling medium can enter the interior of the battery cell 11 earlier, reduce the temperature inside the battery cell 11, and suppress heat spread.

[0138] In some embodiments, the wall thickness of the meltable portion of the first liquid cooling plate 3 is 0.1 mm to 2 mm.

[0139] That is, the wall thickness of the meltable portion of the first liquid cooling plate 3 can be 0.1mm, 0.8mm, or 2mm. The meltable portion refers to the portion within the spray range. For example, when a weak zone is provided in the first liquid cooling plate 3, the meltable portion is the weak zone within the spray range. For another example, when no weak zone is provided, the meltable portion is the portion on the first liquid cooling plate 3 covered by the spray range. Of course, the wall thickness of the first liquid cooling plate 3 can be uniform and range from 0.1mm to 2mm. In this case, there is no need to reduce the wall thickness or provide a weak zone based on the layout position, thereby reducing manufacturing costs and processing difficulty. When thermal runaway occurs in the battery cell 11, it can ensure that the high-temperature material ejected from the explosion-proof valve 113 promptly melts through the portion of the first liquid cooling plate 3 within the spray range. When the wall thickness of the meltable portion of the first liquid cooling plate 3 within the spray range is 0.1mm, due to the thin wall thickness, it can be melted through promptly and the melting speed is fast. The cooling medium can be ejected promptly at the early stage of thermal runaway of the battery cell, thereby improving the suppression effect of heat spread. When the wall thickness of the meltable portion of the first liquid cooling plate 3 within the spray range is 2 mm, the structural strength of this area can be improved, preventing stress concentration and cracking in the corresponding area due to vibration or impact during use. When the wall thickness of the meltable portion of the first liquid cooling plate 3 within the spray range is 0.8 mm, the structural strength of the portion of the first liquid cooling plate 3 within the spray range can be guaranteed while also improving the melt-through speed of the corresponding portion.

[0140] For example, when the main body of the first liquid cooling plate 3 is made of metal, the shell wall thickness of the first liquid cooling plate 3 is 2.5 mm, and the wall thickness of the first liquid cooling plate 3 within the spraying range is set to 0.2 mm, thereby forming a weak area to ensure that the weak area can be melted through in time.

[0141] For another example, when the entire first liquid cooling plate is made of composite material, even if the wall thickness of the first liquid cooling plate 3 within the spraying range is not reduced, it can be melted through in time. Therefore, no weak area is required, and the wall thickness of the entire first liquid cooling plate is 2 mm.

[0142] When the wall thickness of the first liquid cooling plate 3 within the spray range is too thin and less than 0.1 mm, for example, when the wall thickness of the first liquid cooling plate 3 is 0.086 mm, 0.07 mm, or 0.06 mm, the structural stability of the first liquid cooling plate 3 is poor, and it is easy to be damaged due to its own structural stability, resulting in leakage of the cooling medium without losing control of the battery cell 11.

[0143] When the wall thickness of the first liquid cooling plate 3 within the spraying range is too thick and is greater than 2 mm, for example, when the wall thickness of the first liquid cooling plate 3 is 2.5 mm, 3 mm, or 3.7 mm, the melting-through time of the first liquid cooling plate 3 within the spraying range will be long, and the size of the melting-through gap of the first liquid cooling plate 3 will become smaller. The cooling medium cannot be sprayed in time, and the runaway battery cell 11 cannot be effectively covered, which affects the control effect of heat spread after thermal runaway and increases uncontrollable factors.

[0144] Furthermore, the cooling medium in the first liquid cooling plate 3 of the embodiment of the present disclosure can be connected to the liquid cooling circuit of the battery thermal management system, which can perform thermal management on the battery cell 11 pole 111 and improve the battery charging and discharging performance and cycle life.

[0145] However, when the cooling device in the related art uses non-metallic materials, the thermal conductivity of ordinary non-metallic materials is low (≤0.4W / m·K), and the thermal management effect of non-metallic materials on the battery cell 11 and its electrical connection bar 2 is poorer than that of the first liquid cooling plate 3 made of metal materials. Therefore, the thermal conductivity of the first liquid cooling plate 3 in the embodiment of the present disclosure is greater than or equal to 0.5W / m·K, and can specifically be 0.5W / m·K, 0.8, 1.1W / m·K, 2W / m·K or a higher thermal conductivity. For example, the material of the first liquid cooling plate 3 is a composite material including PPA (polyphthalamide) with a thermal conductivity of 0.75W / m·K, or the material of the first liquid cooling plate 3 is a composite material including PPO (polystyrene) with a thermal conductivity of 1W / m·K. At this time, the thermal management effect of the first liquid cooling plate 3 using the composite material on the battery cell 11 in the embodiment of the present disclosure can be basically the same as the effect achieved by the metal first liquid cooling plate 3 in the related art, and can transfer the heat on the pole 111 to the cooling medium in the first liquid cooling plate 3 and quickly diffuse it out, thereby meeting the thermal management requirements of the battery under normal fast charging conditions.

[0146] Therefore, the first liquid cooling plate 3 of the embodiment of the present disclosure can spray cooling medium under the condition of thermal runaway of the battery cell, thereby suppressing heat spread, and can also cool the pole and improve the thermal management performance of the battery cell.

[0147] When the first liquid cooling plate 3 of the disclosed embodiment is made of composite material, the overall material and properties tend to be consistent. Therefore, the first liquid cooling plate 3 does not need to be provided with a weak area, and the high-temperature material sprayed from the battery cell 11 can more accurately and promptly melt through the portion of the first liquid cooling plate 3 within the spraying range.

[0148] The cooling medium in the first liquid cooling plate 3 can be water, 50% ethylene glycol coolant, fluorinated liquid, refrigerant (R134a, etc.) and other cooling materials.

[0149] In the disclosed embodiment, the first liquid cooling plate 3 can not only spray cooling medium on the runaway battery cell 11 by locally melting through when the battery cell 11 is in thermal runaway, thereby achieving a cooling effect, but can also cool the pole 111 when the battery cell 11 is operating normally, thereby improving the thermal management performance of the battery, reducing the temperature of the battery during normal operation, and avoiding thermal runaway of the battery.

[0150] Therefore, the first liquid cooling plate 3 and the pole 111 are connected via a heat conducting layer, which improves the heat transfer performance between the first liquid cooling plate 3 and the pole 111. The heat conducting layer can be a heat conducting glue, a heat conducting pad, a double-sided tape or a structural adhesive.

[0151] Alternatively, the first liquid cooling plate 3 is directly connected to the pole 111 without any contact, and the first liquid cooling plate 3 and the pole 111 are directly in contact with each other to achieve heat transfer.

[0152] Table 1 Comparison of performance parameters of aluminum alloy liquid cooling device and non-metallic first liquid cooling plate under thermal runaway conditions

[0153] It can be seen from the test data in Table 1 that when the first offset distance between the first liquid cooling plate and the battery cell explosion-proof valve in the embodiment of the present disclosure is 10 mm, 1 mm, and 8 mm, the maximum temperature of the battery cells adjacent to the runaway battery cell can be effectively reduced (by 58.3°C, 60.7°C, and 68.8°C, respectively), compared with the aluminum alloy liquid cooling device in the related art. This inhibits the spread of heat from the runaway battery cell to the adjacent battery cells, thereby ensuring the safety of the battery system and avoiding the consequences of cascading thermal runaway.

[0154] Furthermore, the test results in Table 1 for first offset distances D between the first liquid cooling plate and the explosion-proof valve of 1 mm, 8 mm, and 10 mm show that even if the staggered first offset distances are different, the cooling effects are relatively small, and all can meet the requirement of suppressing the spread of thermal runaway of the battery cells.

[0155] The test results in Table 1 for first offset distances D between the first liquid cooling plate and the explosion-proof valve of 1mm, 8mm, and 10mm show that the first offset distance D between the first liquid cooling plate and the explosion-proof valve is not necessarily better when it is smaller, nor is it necessarily better when it is larger. Therefore, the embodiments of the present disclosure optimize the design of the first offset distance D and the second offset distance H to meet the requirement of preventing heat spread during thermal runaway of the battery cell.

[0156] Table 2 Performance parameter comparison of aluminum alloy liquid cooling device and non-metal first liquid cooling plate under fast charging condition

[0157] As shown in Table 2, simulations show that using the solution provided in this embodiment, the thermal conductivity of the first liquid cooling plate is 0.7 W / m·K, enabling a 628-second fast charge and a 500 km range. Compared to traditional aluminum alloy liquid cooling systems, the fast charge time is only extended by 12 seconds, a relatively small difference, meeting the thermal management requirements under fast charging conditions.

[0158] In some embodiments, there are multiple battery cells 11, and the multiple battery cells 11 are arranged in an array to form a battery module 1. The battery module 1 includes at least one battery group arranged along a first direction, and the first liquid cooling plate 3 extends along the first direction; wherein the first direction is perpendicular to the height direction of the battery cell 11.

[0159] It should be understood that the front-to-back direction shown in FIG4 is the length direction of the battery cell 11, the left-to-right direction shown in FIG4 is the width direction of the battery cell 11, and the up-down direction shown in FIG4 is the height direction of the battery cell 11. The first direction can be the length direction of the battery cell 11 or the width direction of the battery cell 11, and this direction determines the extension direction of the first liquid cooling plate 3, while ensuring the relative positional relationship between the first liquid cooling plate 3 and the explosion-proof valve 113, and ensuring that if any of the multiple battery cells 11 experiences thermal runaway, the first liquid cooling plate 3 can promptly melt through and spray cooling medium to the runaway battery cell 11.

[0160] Furthermore, the length of the first liquid cooling plate 3 in the first direction is greater than or equal to the length of the battery pack in the first direction.

[0161] It should be noted that the first direction can be the length direction or the width direction of the battery cell 11. Each battery pack in the battery module includes multiple battery cells 11. The multiple battery cells 11 in the same battery pack are arranged side by side along the length direction of the battery cell 11 or the width direction of the battery cell 11. By limiting the length of the first liquid cooling plate 3, the first liquid cooling plate 3 can cover all battery cells 11 along the battery pack. At this time, if any battery cell 11 has thermal runaway, the sprayed cooling medium can be accurately sprayed onto the thermal runaway battery cell 11 by melting through the part of the first liquid cooling plate 3 within the spraying range.

[0162] In some embodiments, the first direction is the length direction of the battery cell 11 , two first liquid cooling plates 3 are attached above a pole 111 , the two first liquid cooling plates 3 are arranged at intervals along the width direction of the battery cell 11 , and the explosion-proof valve 113 is located between the two first liquid cooling plates 3 .

[0163] It should be understood that the pole 111 in the battery cell 11 includes a positive pole and a negative pole, and the positive pole, the explosion-proof valve 113 and the negative pole are arranged at intervals along the length direction of the battery cell 11. When the cross-sectional size of the pole 111 is large and the cross-sectional size of the explosion-proof valve 113 (that is, the explosion-proof valve of the battery cell 11) is smaller than that of the pole 111, two first liquid cooling plates 3 can be set on one pole 111, and the first liquid cooling plates 3 extend along the length direction of the battery cell 11. The two first liquid cooling plates 3 are respectively arranged on both sides of the explosion-proof valve of the battery cell 11, and the projections of the two first liquid cooling plates 3 and the explosion-proof valve of the battery cell 11 in the height direction of the battery cell 11 are completely deviated from each other. When the battery cell 11 thermally runs away, the high-temperature material ejected from the explosion-proof valve of the battery cell 11 can simultaneously melt through the weak areas on the two first liquid cooling plates 3, thereby having a better cooling effect on the battery cell 11.

[0164] In some embodiments, the first direction is the width direction of the battery cell 11 , and a first liquid cooling plate 3 is attached above one pole 111 .

[0165] At this time, as shown in Figure 1, the first liquid flow plate extends along the width direction of the battery cell 11, and a first liquid flow plate is provided on the positive electrode column and the negative electrode column of the battery cell 11, and the two first liquid flow plates located on the positive electrode column and the negative electrode column are arranged on both sides of the explosion-proof valve 113. When the explosion-proof valve 113 sprays out high-temperature material, the high-temperature material can also simultaneously melt through the first liquid cooling plates 3 on both sides within the spraying range, so that the first liquid cooling plates 3 on both sides spray out cooling medium at the same time, so that the sprayed cooling medium can completely cover the explosion-proof valve 113, thereby improving the cooling effect.

[0166] Optionally, a heat-conducting layer is provided between the first liquid cooling plate 3 and the pole 111 . The heat-conducting layer may be a heat-conducting structural adhesive, a heat-conducting pad, a heat-conducting gel, a heat-conducting silicone grease, a structural adhesive, etc., to improve the heat transfer efficiency between the first liquid cooling plate 3 and the pole 111 .

[0167] As shown in FIG. 5 to FIG. 7 , the battery module assembly 100 of the embodiment of the present disclosure further includes a tab 2 , which is connected to the pole 111 , and a first liquid cooling plate 3 is attached to the tab 2 .

[0168] At this time, the heat conducting layer is provided between the first liquid cooling plate 3 and the bar 2 , thereby improving the heat transfer efficiency between the bar 2 and the first liquid cooling plate 3 .

[0169] The battery module assembly 100 of the embodiment of the present disclosure includes a battery module 1 , a bar 2 and a first liquid cooling plate 3 .

[0170] The battery module 1 includes a plurality of battery cells 11 arranged along the width direction (for example, the left-right direction shown in FIG4 ), and a plurality of tabs 2, each of which is connected to the poles 111 of two adjacent battery cells 11 to form a tab row; the first liquid cooling plate 3 extends along the width direction, and the first liquid cooling plate 3 is attached to the tab row along the height direction (for example, the up-down direction shown in FIG4 ).

[0171] The battery module assembly 100 of the embodiment of the present disclosure, by providing a first liquid cooling plate 3 on the bar 2 connected to the pole 111, can directly dissipate the heat generated on the pole 111 promptly and quickly through the first liquid cooling plate 3, thereby improving the overall cooling capacity of the battery module 1 by the first liquid cooling plate 3, preventing heat from accumulating at the pole 111 and causing the battery cell 11 to be overheated, limiting the charging current, and being suitable for fast-charging batteries, thereby helping to improve the fast-charging capability and safety of the battery module 1.

[0172] Therefore, the battery module assembly 100 of the embodiment of the present disclosure has the advantage of suppressing heat spread when the battery cell is in thermal runaway, and at the same time has the advantage of improving the heat dissipation capacity and fast charging capacity at the pole 111 under normal operating conditions.

[0173] Furthermore, there are multiple tabs 2, each of which is connected to the poles 111 of two adjacent battery cells 11 to form a tab row. The first liquid cooling plate 3 is attached to the tab row. The tabs 2 can connect two adjacent battery cells 11 in the battery module 1 in series and / or in parallel. The poles 111 are positioned on top of the battery cells 11, the tabs 2 are connected to the poles 111, and the first liquid cooling plate 3 is positioned on the upper surface of the tabs 2.

[0174] In some embodiments, as shown in FIG6 and FIG7 , the first liquid cooling plate 3 includes a connected liquid cooling portion 31 and an overlapping edge 32 . The liquid cooling portion 31 is attached to the tab array, and the overlapping edge 32 is attached to the shoulder 112 of the battery cell 11 .

[0175] The battery module assembly 100 of the disclosed embodiment divides the first liquid cooling plate 3 into a connected liquid cooling portion 31 and an overlapping edge 32. The liquid cooling portion 31 is attached to the bar array, and the overlapping edge 32 is attached to the shoulder 112 of the battery cell 11. The overlapping edge 32 can not only dissipate heat from the shoulder 112 of the battery cell 11, but also dissipate heat from the shoulder 112 of the battery cell 11 through the liquid cooling portion 31. This not only helps to reduce or even eliminate the temperature difference between the shoulder 112 of the battery cell 11 and the pole 111 (the overlapping edge 32 has the function of uniform heat distribution), but also reduces the overall cooling capacity of the battery module 1. As a result, the battery module assembly 100 further improves the heat dissipation capacity of the battery module 1.

[0176] For example, the battery pack in the battery module 1 includes a plurality of battery cells 11 arranged along the width of the battery cells 11, and each battery cell 11 has a shoulder 112. The positive and negative electrode posts of the battery cells 11 are both arranged on the top surface of the battery cells 11. When the positive and negative electrode posts are arranged near the middle of the battery cells 11, the shoulders 112 can be formed on both sides of the length of the battery cells 11, as shown in FIG15. When the positive and negative electrode posts are arranged near the edges of the length of the battery cells 11, the shoulders 112 are formed between the explosion-proof valve 113 and the positive electrode post, and between the explosion-proof valve 113 and the negative electrode post.

[0177] When the positive and negative poles of the battery cell 11 are relatively arranged at the top and bottom of the battery cell 11. For example, the positive pole is arranged in the middle area of ​​the top surface of the battery cell 11, and the shoulders 112 can be formed on both sides of the positive pole of the battery cell 11 along the length direction, for example, a blade battery cell 11.

[0178] For another example, the battery pack in the battery module 1 includes a plurality of battery cells 11 arranged along the length direction of the battery cells 11, and each battery cell 11 has a shoulder 112. The positive and negative electrode posts of the battery cells 11 are both arranged on the top surface of the battery cells 11, and the shoulders 112 can be formed on both sides of the battery cells 11 in the width direction.

[0179] Tab 2 is welded, screwed, riveted, or bonded with conductive adhesive to the post 111 of the battery module 1. Thus, the battery module assembly 100 of the disclosed embodiment has the advantage of high connection convenience. For example, tab 2 connecting battery cells 11 can be connected to the post 111 of the battery cell 11 through processes such as riveting or laser welding, thereby achieving high-voltage series or parallel connection of the entire battery module 1.

[0180] Optionally, the tab 2 may be a copper alloy tab 2 or an aluminum alloy tab 2, and an observation hole is provided on the tab 2. Furthermore, the tab 2 may be formed by a process such as stamping, machining or casting.

[0181] Optionally, the bar 2 and the first liquid cooling plate 3 are connected via various heat-conducting media such as heat-conducting structural adhesive, heat-conducting pad, heat-conducting gel, heat-conducting silicone grease, structural adhesive, etc.

[0182] Optionally, the pole 111 may be square or circular. The pole 111 generally includes a positive pole and a negative pole, which may be disposed on the same end face of the battery module 1 or disposed opposite to each other.

[0183] As shown in Figure 8, in the length direction of the battery cell 11, the ratio between the length L1 of the pole 111 and the length L3 of the battery cell 11 is 0.1-0.4. This avoids the problem of the top surface of the battery cell 11 not having enough area to accommodate the necessary electrical safety distance between the positive pole and the negative pole of the battery cell 11 when the ratio is too large (exceeding 0.40), resulting in poor safety; and avoids the problem of the top surface of the battery cell 11 being too small, resulting in a small proportion of the area of ​​the first liquid cooling plate 3 in contact with the top of the battery cell 11, which in turn leads to poor heat exchange efficiency at the top of the battery cell 11. Therefore, the battery module assembly 100 has the advantages of good cooling effect and high structural strength.

[0184] Specifically, the positive electrode column and the negative electrode column of the battery cell 11 are both arranged on the same side of the battery cell 11 , or there may be two or more positive electrode columns and two or more negative electrode columns.

[0185] As shown in Figure 8 , the ratio of the width L2 of the pole 111 to the width L4 of the cell 11, along the width of the battery cell 11, is 0.1-0.99. This avoids the problem of poor cooling performance caused by an excessively small ratio between the width L2 of the pole 111 and the width L4 of the battery cell 11, and also avoids the problem of interference with the installation of the first liquid cooling plate 3 caused by an excessively large ratio between the width L2 of the pole 111 and the width L4 of the battery cell 11. Therefore, the battery module assembly 100 combines the advantages of excellent cooling performance with high installation convenience.

[0186] The ratio of the width L2 of the pole 111 to the width L4 of the battery cell 11 can be 0.1, 0.4 or 0.99. When the ratio of the width L2 of the pole 111 to the width L4 of the battery cell 11 is 0.1, reducing the volume of the pole 111 can create a larger space between the first liquid cooling plate 3 and the end face of the battery cell, making it easier for the high-temperature material ejected from the explosion-proof valve 113 to diffuse.

[0187] When the ratio between the width L2 of the pole 111 and the width L4 of the battery cell 11 is 0.99, the end face of the pole 111 has a larger area, which can increase the contact area between the pole 111 and the first liquid cooling plate 3, and increase the heat dissipation rate of the pole 111. In addition, when the first liquid cooling plate 3 extends along the length direction of the battery cell, and two first liquid cooling plates 3 are arranged at intervals along the width direction of the battery cell on each pole 111, the pole 111 has sufficient width to arrange two first liquid cooling plates 3, ensuring that the first liquid cooling plate 3 has sufficient contact area with the pole, improving the cooling effect of the pole, and at the same time meeting the spatial position requirements between the first liquid cooling plate 3 and the explosion-proof valve 113 as defined in the above embodiment, thereby effectively suppressing heat spread during thermal runaway of the battery cell.

[0188] When the ratio of the width L2 of the pole 111 to the width L4 of the battery cell 11 is 0.4, it can ensure sufficient contact area between the pole 111 and the first liquid cooling plate 3 while providing more space between the first liquid cooling plate and the end face of the battery cell.

[0189] As shown in Figure 8 , along the length of the battery cell 11, the ratio of the length of the tab 2 to the length L1 of the terminal 111 is 0.1-5. This avoids the problem of tab 2 interfering with installation when the ratio is too large, while also avoiding the problem of tab 2 interfering with installation when the ratio is too small, which would result in a small contact surface between tab 2 and terminal 111 and poor electrical connection or heat exchange efficiency in the battery cell 11. Therefore, the battery module assembly 100 combines the advantages of good cooling performance with high installation convenience.

[0190] The ratio of the length of the bar 2 to the length L1 of the pole 111 can be 0.1, 1.5 or 5. When the ratio of the length of the bar 2 to the length L1 of the pole 111 is 0.1, the bar can be prevented from interfering with the first liquid cooling plate 3 or other components during installation, and the space between the first liquid cooling plate 3 and the end face of the battery cell can be saved, which is helpful for the eruption and diffusion of high-temperature materials during thermal runaway of the battery cell; when the ratio of the length of the bar 2 to the length L1 of the pole 111 is 5, there is a larger fitting area between the bar 2 and the pole 111, and between the bar 2 and the first liquid cooling plate 3, which can improve the heat transfer effect and improve the cooling effect of the first liquid cooling plate 3 on the pole 111.

[0191] When the ratio of the length of the bar 2 to the length L1 of the pole 111 is 1.5, it can ensure that there is a larger fitting area between the bar 2 and the pole 111, and between the bar 2 and the first liquid cooling plate 3, while avoiding position interference between the bar 2 and the explosion-proof valve 113, and avoiding the space between the first liquid cooling plate 3 and the end face of the battery cell due to the excessive length of the bar 2.

[0192] Furthermore, the ratio of the length of the tab 2 to the length L1 of the pole 111 is 1.5-5. In other words, the length of the tab 2 is greater than the length of the pole 111. Furthermore, the tab 2 includes a connected overlapping portion and an extended portion. The overlapping portion overlaps the two poles 111 of two adjacent battery cells 11, and the extended portion extends to the shoulder 112 of the battery cell 11. This improves the electrical connection stability between the tabs and the heat exchange efficiency between the first liquid cooling plate and the pole without affecting the opening of the explosion-proof valve and the ejection of high-temperature materials.

[0193] As shown in FIG9 , in a second direction perpendicular to the first direction and the height direction of the battery cell 11 (that is, when the first direction is the length direction of the battery cell 11, the second direction is the width direction of the battery cell 11; when the first direction is the width direction of the battery cell 11, the second direction is the length direction of the battery cell 11), the ratio of the length L5 of the liquid cooling portion 31 to the length L6 of the bar 2 is 0.1-2. This avoids the problem of poor cooling effect caused by the ratio of the length of the liquid cooling portion 31 to the length of the bar 2 being too small. It also avoids the problem of a small contact area between the liquid cooling portion 31 and the bar 2 caused by the ratio of the length of the liquid cooling portion 31 to the length of the bar 2 being too large, thereby avoiding the advantage of wasting material in the liquid cooling portion 31. The ratio of the length L5 of the liquid cooling portion 31 to the length L6 of the tab 2 can be 0.1, 1, or 2. When the ratio is 0.1, the cost of the first liquid cooling plate 3 can be reduced. Furthermore, the position of the first liquid cooling plate 3 in the second direction can be more flexibly adjusted, allowing for better adjustment of the spatial relationship between the first liquid cooling plate 3 and the explosion-proof valve 113, thereby improving the effectiveness of the first liquid cooling plate 3 in suppressing heat spread during thermal runaway of the battery cell. When the ratio is 2, the contact area between the first liquid cooling plate 3 and the tab 2 can be increased, thereby enhancing heat transfer.

[0194] When the ratio of the length of the liquid cooling portion 31 to the length of the bar 2 can be 1, the battery module assembly 100 can achieve better results in cooling efficiency, cost, and the effect of suppressing the spread of thermal runaway.

[0195] As shown in Figures 4 and 10-14, in some embodiments, the battery module assembly 100 of the disclosed embodiments further includes a second liquid cooling plate 4, which is disposed in contact with the battery cell 11 and opposite to the first liquid cooling plate 3. It is understood that the second liquid cooling plate 4 and the first liquid cooling plate 3 are disposed opposite each other in the height direction of the battery cell 11 (as shown in the vertical direction in Figure 4).

[0196] The battery module assembly 100 of the disclosed embodiment cools the other side of the battery module 1 by disposing a second liquid cooling plate 4 on the side of the battery module 1 opposite the first liquid cooling plate 3. This further improves the heat dissipation efficiency and uniformity of the battery module 1.

[0197] As shown in Figures 13 and 14, in the embodiment of the present disclosure, a first cooling channel 311 is provided in the first liquid cooling plate 3, and a second cooling channel 41 is provided in the second liquid cooling plate 4. Each of the first cooling channel 311 and the second cooling channel 41 has a cooling medium for cooling the battery module 1.

[0198] The battery module assembly 100 of the disclosed embodiment, by providing a first cooling channel 311 within the first liquid cooling plate 3 and a second cooling channel 41 within the second liquid cooling plate 4, controls the flow path of the cooling medium, thereby extending the time the cooling medium flows through the liquid cooling plates (first liquid cooling plate 3 and second liquid cooling plate 4), thereby improving the cooling effect of the liquid cooling plates. As a result, the battery module assembly 100 improves the heat dissipation effect of the battery module 1.

[0199] Optionally, the first liquid cooling plate 3 and the second liquid cooling plate 4 may be in the form of harmonica tubes or may be stamped and brazed.

[0200] Furthermore, the battery module assembly 100 of the embodiment of the present disclosure also includes a first convergence piece and a second convergence piece, and the first cooling channel 311 and the second cooling channel 41 both include multiple branch channels extending along the second direction. The first convergence piece is correspondingly arranged at both ends of the extension direction of the first liquid cooling plate 3, and the second convergence piece is correspondingly arranged at both ends of the extension direction of the second liquid cooling plate 4.

[0201] In the battery module assembly 100 of the disclosed embodiment, the first cooling channel 311 and the second cooling channel 41 each include multiple sub-channels extending along the extension direction of the first liquid cooling plate 3 or the second liquid cooling plate 4. This expands the area covered by the cooling channel when flowing through the liquid cooling plate, thereby further improving the cooling effect of the liquid cooling plate on the battery module 1. Furthermore, the first and second conduits are provided to converge the cooling medium in the sub-channels, eliminating the need for connecting pipes to each sub-channel, thereby improving the convenience of connection and layout.

[0202] As shown in FIG10 , the battery module assembly 100 of the embodiment of the present disclosure further includes a liquid inlet pipe 51 and a liquid outlet pipe 52 . The liquid inlet pipe 51 , the first liquid cooling plate 3 , the liquid outlet pipe 52 and the second liquid cooling plate 4 are connected in sequence.

[0203] The battery module assembly 100 of the embodiment of the present disclosure connects the first liquid cooling plate 3 and the second liquid cooling plate 4 through the provided liquid inlet pipe 51 and liquid outlet pipe 52 to realize the circulation of the internal cooling medium, thereby improving the uniformity and control convenience of the cooling of the battery module 1.

[0204] Optionally, as shown in FIG11 , there may be multiple first liquid cooling plates 3, and the first liquid cooling plates 3 may be connected in parallel or in series and then connected to the second liquid cooling plate 4. Furthermore, as shown in FIG12 , the second liquid cooling plate 4 may be a plate structure having a liquid cavity, and the plate structure has a liquid outlet and a liquid inlet. The battery module 1 may have multiple rows of battery cells arranged in a row, each battery cell row may have two shoulders 112, and each shoulder 112 is provided with a first liquid cooling plate 3. Multiple first liquid cooling plates 3 may be connected in series or in parallel to form a whole and then connected to the second liquid cooling plate 4.

[0205] As shown in Figure 13, the second liquid cooling plate 4 has a heat exchange panel 42 and a flow channel panel 43 arranged opposite each other along the height of the battery cell 11. These panels 42 and 43 form a second cooling channel 41. The contact area between the heat exchange panel 42 and the battery module 1 is S1, and the area of ​​the battery module 1 connected to the heat exchange panel 42 is S2. The ratio of S1 to S2 is 0.1-1. This avoids the problem of poor cooling effect caused by the small heat exchange area of ​​the second liquid cooling plate 4, while also preventing the problem of an overly large heat exchange panel 42 occupying the internal space of the battery pack 1000.

[0206] As shown in Figure 13, in some embodiments, along the height of the battery cell 11, the thickness of the heat exchange panel 42 is D1, the dimension of the second cooling channel 41 is H1, and 0.02≤D1 / H1≤5; the thickness of the flow channel panel 43 is D2, and the dimension of the second cooling channel 41 is H1, and 0.02≤D2 / H1≤5. Thus, the battery module assembly 100 avoids both the problem of poor cooling effect caused by excessive thickness of the heat exchange panel 42 and / or flow channel panel 43 occupying space in the second cooling channel 41, and the problem of weak structural strength caused by excessive thickness of the heat exchange panel 42 and / or flow channel panel 43. Therefore, the battery module assembly 100 combines the advantages of good cooling effect and high structural strength.

[0207] The D1 / H1 ratio can be 0.02, 2, or 5. When the D1 / H1 ratio is 0.02, the thickness of the heat exchange panel 42 can be reduced, avoiding occupying the space of the second cooling channel 41. This improves the cooling effect of the cooling medium in the channel and on the battery cells. It also saves space in the height direction of the battery cells to increase the power density of the battery and reduce the material cost of the second liquid cooling plate 4. When the D1 / H1 ratio is 5, the structural strength of the heat exchange panel can be improved. When the D1 / H1 ratio is 2, the heat exchange panel 42 can have the advantages of good cooling effect, cost savings, and high structural strength.

[0208] The D2 / H1 ratio can be 0.02, 3, or 5. When the D2 / H1 ratio is 0.02, the thickness of the flow channel panel 43 can be reduced, avoiding occupying the space of the second cooling channel 41, improving the cooling effect, and saving space in the height direction of the battery cell to increase the power density of the battery and save material costs. When the D2 / H1 ratio is 5, the structural strength of the heat exchange panel can be improved, preventing the flow channel panel 43 from deformation due to squeezing or collision. When the D2 / H1 ratio is 3, the flow channel panel 43 can have the advantages of good cooling effect, cost savings, and high structural strength.

[0209] Optionally, the heat exchange panel 42 can be a flat plate, and the flow channel panel 43 can be a corrugated structure plate. The heat exchange panel 42 and the flow channel panel 43 can be formed into the second liquid cooling plate 4 by stamping, brazing, and inflation manufacturing. The second liquid cooling plate 4 can also be a harmonica tube or aluminum profile tube.

[0210] Optionally, in order to ensure the connection strength between the second liquid cooling plate 4 and the battery module 1 and further improve the cooling effect between the second liquid cooling plate 4 and the battery module 1, the heat conduction between the second liquid cooling plate 4 and the battery module 1 can be increased by various heat exchange media such as thermal pads, thermal adhesives, structural adhesives, double-sided tape, etc.

[0211] As shown in Figure 14, in the height direction of the battery cell 11, the thickness of the side where the first liquid cooling plate 3 connects to the bar 2 (heat dissipation surface 312) is D3, and the size of the first cooling channel 311 is H2, where 0.02≤D3 / H2≤2. Thus, the battery module assembly 100 avoids the problem of poor cooling effect caused by the excessive thickness of the first liquid cooling plate 3 occupying the space of the first cooling channel 311, and also avoids the problem of weak structural strength caused by the thickness of the first liquid cooling plate 3 being too small. Therefore, the battery module assembly 100 has the advantages of both good cooling effect and high structural strength.

[0212] The ratio D3 / H2 can be 0.02, 1, or 2. When the ratio D3 / H2 is 0.02, the thickness of the heat dissipation surface 312 can be reduced, avoiding occupying the space of the first cooling channel 311, improving the cooling effect, and saving space in the height direction of the battery cell to increase the power density of the battery and save the material cost of the first liquid cooling plate 3. When the ratio D3 / H2 is 2, the structural strength of the heat dissipation surface 312 can be improved, preventing the heat dissipation surface 312 from deformation due to squeezing or collision. When the ratio D3 / H2 is 1, the heat dissipation surface 312 can have the advantages of good cooling effect, cost saving, and high structural strength.

[0213] As shown in Figure 1, the battery pack 1000 of the embodiment of the present disclosure includes a housing 200 and a battery module assembly 100 according to any of the above embodiments disposed within the housing 200. Therefore, the battery pack 1000 of the embodiment of the present disclosure has the advantages of good fast charging capability and improved heat dissipation capability.

[0214] The vehicle of the disclosed embodiment includes the battery module assembly 100 as in any one of the above embodiments, or the battery pack 1000 as in the above embodiments.

[0215] At least some of the beneficial effects achieved by the vehicle of the disclosed embodiment are the same as or similar to the beneficial effects achieved by the battery module assembly 100 or the battery pack 1000 in the above-mentioned embodiments, and therefore will not be described in detail here.

[0216] The battery module assembly 100 and the battery pack 1000 in the above embodiment can be applied to the new energy industry, including but not limited to vehicles.

[0217] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0218] The foregoing are merely specific embodiments of the present disclosure, intended to enable those skilled in the art to understand and implement the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not to be limited to the embodiments described herein, but is to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A battery module assembly, comprising: a battery cell, the battery cell having a pole and an explosion-proof valve on the same end face in the height direction of the battery cell; a first liquid cooling plate, the first liquid cooling plate being attached above the pole along the height direction of the battery cell; Among them, the projections of the first liquid cooling plate and the explosion-proof valve along the height direction of the battery cell do not overlap, and at least a part of the first liquid cooling plate is within the spraying range of the explosion-proof valve.

2. The battery module assembly according to claim 1, wherein the first liquid cooling plate has a weak area within the spraying range of the explosion-proof valve; and / or, the material of the first liquid cooling plate is a composite material.

3. The battery module assembly according to claim 1, wherein there is a first offset distance between the projections of the first liquid cooling plate and the explosion-proof valve along the height direction of the battery cell, and the first offset distance is 0 to 30 mm; and / or, there is a second offset distance between the first liquid cooling plate and the explosion-proof valve in the height direction of the battery cell, and the second offset distance is 0 to 20 mm; and / or, the melting point of the melt-through part of the first liquid cooling plate is less than or equal to 400 °C.

4. The battery module assembly according to claim 1, wherein the wall thickness of the melt-through part of the first liquid cooling plate is 0.1 mm to 2 mm; and / or the thermal conductivity of the first liquid cooling plate is greater than or equal to 0.5 W / m·K.

5. The battery module assembly according to any one of claims 1-4, wherein the number of the battery cells is multiple, and the multiple battery cells are arranged in an array to form a battery module. The battery module includes at least one battery pack arranged in a first direction, the first liquid cooling plate extends along the first direction, and the length of the first liquid cooling plate in the first direction is greater than or equal to the length of the battery pack in the first direction; Among them, the first direction is perpendicular to the height direction of the battery cell.

6. The battery module assembly according to claim 5, wherein the first direction is the length direction of the battery cell, and two first liquid cooling plates are attached above one pole, and the two first liquid cooling plates are arranged at intervals along the width direction of the battery cell, and the explosion-proof valve is located between the two first liquid cooling plates; or, the first direction is the width direction of the battery cell, and one first liquid cooling plate is attached above one pole.

7. The battery module assembly according to claim 1, further comprising a tab, the tab is connected to the pole, and the first liquid cooling plate is attached to the tab.

8. The battery module assembly according to claim 1, wherein the first liquid cooling plate and the pole are connected through a thermal conductive layer.

9. The battery module assembly according to claim 1, further comprising a second liquid cooling plate, the second liquid cooling plate is arranged in contact with the battery cell, and the second liquid cooling plate and the first liquid cooling plate are arranged opposite to each other in the height direction of the battery cell.

10. A battery module assembly, comprising: a battery module, the battery module including multiple battery cells arranged in a width direction; tabs, there are multiple tabs, and each tab is connected to the poles of two adjacent battery cells to form a tab row; The first liquid cooling plate extends along the width direction, and the first liquid cooling plate is attached to the bar plate row along the height direction perpendicular to the width direction.

11. The battery module assembly according to claim 10, wherein the first liquid cooling plate includes a connected liquid cooling portion and a lapping edge, the liquid cooling portion is attached to the bar plate row, and the lapping edge is attached to the shoulder of the battery cell; and / or, the bar plate is welded, screwed, riveted or adhesively bonded with an electrically conductive adhesive to the pole column of the battery module.

12. The battery module assembly according to claim 11, in the length direction perpendicular to the width direction and the height direction, the ratio between the length L1 of the pole column and the length L3 of the battery module is 0.1 - 0.4; and / or, in the width direction, the ratio between the width L2 of the pole column and the width L4 of the battery module is 0.1 - 0.99; and / or, in the length direction perpendicular to the width direction and the height direction, the ratio between the length of the bar plate and the length L1 of the pole column is 0.1 - 5; and / or, in the length direction perpendicular to the width direction and the height direction, the ratio between the length L5 of the liquid cooling portion and the length L6 of the bar plate is 0.1 - 2.

13. The battery module assembly according to claim 10, further comprising a second liquid cooling plate, the second liquid cooling plate is configured to be disposed on the battery module, and the second liquid cooling plate is disposed opposite to the first liquid cooling plate.

14. The battery module assembly according to claim 13, the first liquid cooling plate is provided with a first cooling channel, the second liquid cooling plate is provided with a second cooling channel, and each of the first cooling channel and the second cooling channel has a cooling medium for cooling the battery module.

15. The battery module assembly according to claim 14, further comprising an inlet pipe and an outlet pipe, the inlet pipe, the first liquid cooling plate, the outlet pipe and the second liquid cooling plate are connected in sequence.

16. The battery module assembly according to claim 14, the second liquid cooling plate has a heat exchange panel and a flow channel panel disposed opposite to each other along the width direction, the heat exchange panel and the flow channel panel form the second cooling channel, the area of the heat exchange panel in contact with the battery module is S1, the area of the side of the battery module connected to the heat exchange panel is S2, and the ratio of S1 to S2 is 0.1 - 1; and / or, in the width direction, the thickness of the heat exchange panel is D1, the size of the second cooling channel is H1, 0.02 ≤ D1 / H1 ≤ 5; the thickness of the flow channel panel is D2, the size of the second cooling channel is H1, 0.02 ≤ D2 / H1 ≤ 5; and / or, in the width direction, the thickness of the side of the first liquid cooling plate connected to the bar plate is D3, the size of the second cooling channel is H2, 0.02 ≤ D3 / H2 ≤ 2.

17. The battery module assembly according to claim 10, further comprising a heat conducting layer, between the first liquid cooling plate and the bar plate.

18. A battery pack, comprising the battery module assembly according to any one of claims 1-17.

19. The battery pack according to claim 18, further comprising a housing, wherein the battery module assembly is disposed within the housing.

20. A vehicle, comprising the battery module assembly according to any one of claims 1-17, or the battery pack according to claim 18 or 19.

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