Battery boxes and battery packs

Abstract

The present application discloses a battery box and a battery pack, which relate to the field of battery technology. The battery box includes a box body and a bottom guard plate arranged on the outside of the bottom of the box body. The box body includes a liquid-cooled bottom plate and side plates. The side plates and the liquid-cooled bottom plate form a receiving cavity for accommodating battery cells. The liquid-cooled bottom plate and the bottom guard plate are spaced apart to form a first exhaust cavity. The liquid-cooled bottom plate is provided with a liquid-cooling channel and a buffer cavity that are not connected to each other. The liquid-cooled bottom plate is provided with a liquid inlet and a liquid outlet connected to the liquid-cooling channel. The buffer cavity has a first opening connected to the receiving cavity and a second opening connected to the first exhaust cavity. The first opening is used to receive the spray ejected when the battery cell is depressurized. In the present application, the buffer cavity and the liquid-cooled channel are integrated in the liquid-cooled bottom plate. The buffer cavity can temporarily accommodate the spray, which can not only alleviate the high pressure, but also prevent the high-temperature and high-pressure spray from directly impacting the bottom guard plate, thereby improving the safety of the entire battery pack.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a battery box and a battery pack. Background Art

[0002] In the prior art, battery cells are provided with pressure relief vents to achieve a targeted release of internal pressure, preventing explosions or unpredictable eruptions during thermal runaway. In related art, explosion-proof valves are provided on the battery box to discharge gases ejected from the battery cells, preventing the internal pressure of the battery box from rising excessively due to the pressure release of the battery cells, which could pose a safety hazard. In battery packs of related art, the flow and discharge of thermal runaway gases are poorly controlled, and the high-temperature, high-pressure ejected material can still easily affect the battery cells within the battery box, resulting in a high risk of heat spread and poor battery pack safety. Summary of the Invention

[0003] The purpose of this application includes providing a battery box and a battery pack, which can effectively contain and discharge the ejected matter of the battery cells, thereby improving the safety of the battery pack.

[0004] The embodiments of the present application can be implemented as follows:

[0005] In the first aspect, the present application provides a battery box, comprising a box body and a bottom guard plate arranged on the outside of the bottom of the box body, the box body comprising a liquid-cooled bottom plate and side plates, the side plates and the liquid-cooled bottom plate forming a accommodating cavity for accommodating battery cells, the liquid-cooled bottom plate and the bottom guard plate are spaced apart to form a first exhaust cavity, liquid-cooled channels and buffer cavities that are not connected to each other are provided in the liquid-cooled bottom plate, a liquid inlet and a liquid outlet connected to the liquid-cooling channel are provided on the liquid-cooled bottom plate, the buffer cavity has a first opening connected to the accommodating cavity and a second opening connected to the first exhaust cavity, the first opening is used to receive the spray ejected when the battery cell is depressurized.

[0006] In an optional embodiment, a blocking member is provided on the liquid cooling base plate, which blocks the first opening. The blocking member is configured to be destroyed when the battery cell is depressurized, so that the ejected matter enters the buffer chamber through the first opening.

[0007] In an optional embodiment, the sealing member includes a limiting portion, a sleeve and a stop wall. The limiting portion is protruded from the outer peripheral surface of the sleeve and is located at one end of the sleeve. The stop wall blocks the other end of the sleeve to form a storage cavity with one end open in the sleeve. The limiting portion abuts against the surface of the liquid-cooled base plate facing the accommodating cavity and is sealed and fixed to the liquid-cooled base plate by a heat-conductive structural adhesive. The sleeve is inserted into the first opening and extends into the buffer cavity, so that the storage cavity extends into the buffer cavity and the opening of the storage cavity faces the accommodating cavity.

[0008] In an optional embodiment, the bottom guard plate is sealed and fixed to the outer periphery of the bottom wall of the side plate, an air inlet is opened on the inner side of the bottom wall of the side plate, and a second exhaust cavity is provided in the side plate, and the second exhaust cavity is connected to the first exhaust cavity through the air inlet;

[0009] An exhaust port is provided on the outer wall of the side plate. The exhaust port is used to connect the second exhaust cavity and the outside of the battery box. The exhaust port is provided with an exhaust valve.

[0010] In an optional embodiment, at least one row of first openings and at least one row of second openings are provided on the liquid-cooled base plate, the first openings correspond one-to-one to the second openings and are opposite to each other in the thickness direction of the liquid-cooled base plate, and the multiple first openings belonging to the same row are arranged along the first direction; the bottom guard plate is provided with a plurality of guide grooves arranged along the first direction, the plurality of guide grooves correspond one-to-one to the plurality of second openings belonging to the same row and are opposite to each other in the thickness direction of the liquid-cooled base plate, and at least one end of the guide groove extends toward the air inlet of the side panel.

[0011] In an optional embodiment, two adjacent guide grooves are separated by a guide rib protruding toward the liquid cooling bottom plate, and the distance between the top of the guide rib and the liquid cooling bottom plate is 3-6 mm.

[0012] In an optional embodiment, the guide groove extends along the second direction, a plurality of air inlets are provided on the inner side of the bottom wall of the side plate, and a plurality of buffer grooves are provided on the bottom guard plate, the plurality of buffer grooves correspond one-to-one to the plurality of guide grooves, and the plurality of air inlets correspond one-to-one to the plurality of buffer grooves; one side of the buffer groove in the second direction is open and faces the end of the guide groove, and one side of the buffer groove in the third direction is open and faces the air inlet; wherein the second direction is perpendicular to the first direction and the third direction, and the third direction is the thickness direction of the liquid-cooled base plate.

[0013] In an optional embodiment, a filter is provided in the first exhaust chamber. The filter is provided between the buffer tank and the end of the guide tank. The filter is used to filter the gas entering the buffer tank from the guide tank.

[0014] In an optional embodiment, a filter is provided in the first exhaust cavity, and the filter is used to filter the gas entering the second exhaust cavity from the first exhaust cavity.

[0015] In an optional embodiment, an exhaust port is provided on the outer wall of the side panel, and an exhaust valve is provided at the exhaust port.

[0016] In an optional embodiment, the liquid-cooled base plate includes a first plate body and a second plate body arranged at intervals, a liquid cooling channel and a buffer cavity are formed between the first plate body and the second plate body, a first opening is arranged on the first plate body, and a second opening is arranged on the second plate body; blocking ribs are arranged between the first plate body and the second plate body, and at least part of the blocking ribs are used to separate the liquid cooling channel and the buffer cavity.

[0017] In an optional embodiment, the liquid cooling channel includes a plurality of sub-channels extending along a first direction, and the plurality of sub-channels are arranged in a second direction, the first direction and the second direction are perpendicular to each other and are both perpendicular to the thickness direction of the liquid cooling base plate; the buffer cavity extends along the first direction and is located between the two sub-channels, the liquid cooling channel also includes a transition channel, the transition channel is adjacent to the buffer cavity in the first direction, and is connected to the two sub-channels adjacent to the buffer cavity in the second direction, and the buffer cavity and the transition channel are separated by a blocking member.

[0018] In a second aspect, the present application provides a battery pack comprising a plurality of battery cells and a battery box according to any one of the aforementioned embodiments, wherein the battery cells are provided with a pressure relief port, the battery cells are arranged on a liquid-cooled base plate, and the pressure relief port is opposite to the first opening.

[0019] In an optional embodiment, the area ratio of the single second opening to the single pressure relief port is 0.35-2.25.

[0020] In an optional embodiment, a liquid inlet pipe and a liquid outlet pipe are provided on the side panel, and the battery pack also includes a cooling plate, which is arranged between two adjacent battery cells and is attached to the two adjacent battery cells. The liquid inlet pipe is connected to the liquid inlet and the cooling plate, and the liquid outlet pipe is connected to the liquid outlet and the cooling plate.

[0021] The battery box and battery pack provided by the embodiments of the present application have the following beneficial effects:

[0022] The battery box provided in this application includes a box body and a bottom guard plate disposed on the outer side of the bottom of the box body. The box body includes a liquid-cooled bottom plate and side plates. The side plates and the liquid-cooled bottom plate form a storage chamber for accommodating battery cells. The liquid-cooled bottom plate and the bottom guard plate are spaced apart to form a first exhaust chamber. The liquid-cooled bottom plate is provided with a liquid cooling channel and a buffer chamber that are not connected to each other. The liquid-cooled bottom plate is provided with a liquid inlet and a liquid outlet that connect to the liquid cooling channel. The buffer chamber has a first opening that connects to the storage chamber and a second opening that connects to the first exhaust chamber. The first opening is used to receive the ejected material ejected when the battery cell is depressurized. In this application, the buffer chamber and the liquid cooling channel are integrated into the liquid-cooled bottom plate, allowing the liquid-cooled bottom plate to simultaneously perform the functions of cooling the battery cell and buffering the ejected material during thermal runaway. When the high-temperature and high-pressure ejected material is ejected from the pressure relief port of the battery cell, it can first enter the buffer chamber through the first opening. The buffer chamber has a certain volume to prevent a sudden increase in pressure. A larger first exhaust chamber, larger than the buffer chamber, is formed between the bottom guard plate and the liquid-cooled bottom plate. Gas within the buffer chamber can enter the first exhaust chamber through a second opening, further releasing pressure. The buffer chamber temporarily contains ejected material, mitigating high pressure while preventing high-temperature, high-pressure ejected material from directly impacting the bottom guard plate, thereby improving the safety of the entire battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a schematic diagram of a battery pack in one embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of a battery cell in one embodiment of the present application;

[0026] Figure 3 This is a schematic diagram of a battery box in an embodiment of the present application at a first viewing angle;

[0027] Figure 4 This is a schematic diagram of a battery box in an embodiment of the present application at a second viewing angle;

[0028] Figure 5 This is a schematic diagram of a liquid cooling base plate according to an embodiment of the present application;

[0029] Figure 6 This is a first cross-sectional view of a battery box in one embodiment of the present application;

[0030] Figure 7 for Figure 6 Enlarged view of the middle part VII;

[0031] Figure 8 This is a cross-sectional view of a liquid cooling base plate in one embodiment of the present application;

[0032] Figure 9 for Figure 6 A magnified view of the middle part IX;

[0033] Figure 10 This is a schematic diagram of a bottom guard plate in one embodiment of the present application;

[0034] Figure 11 This is a second cross-sectional view of a battery box in one embodiment of the present application.

[0035] Icons: 100 - battery box; 101 - receiving chamber; 110 - liquid cooling bottom plate; 111 - first plate; 1111 - first opening; 1112 - liquid inlet; 1113 - liquid outlet; 112 - second plate; 1121 - second opening; 113 - buffer chamber; 114 - blocking rib; 115 - blocking member; 116 - liquid cooling channel; 1161 - sub-channel; 1162 - transition channel; 120 - bottom guard plate; 121 - guide groove; 122 - guide rib; 123-buffer tank; 124-first exhaust chamber; 125-first filter element; 130-side panel; 131-second exhaust chamber; 132-air inlet; 133-second filter element; 134-exhaust valve; 140-blocking member; 141-limiting portion; 142-sleeve; 143-stop wall; 150-thermal conductive structural adhesive; 161-liquid inlet pipe; 162-liquid outlet pipe; 200-battery cell; 210-pressure relief port; 220-pressure relief valve; 300-cooling plate. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0039] In the description of this application, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the invented product is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application.

[0040] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0041] It should be noted that, in the absence of conflict, the features in the embodiments of this application can be combined with each other.

[0042] Figure 1 This is a schematic diagram of a battery pack in one embodiment of the present application. Figure 1 As shown, the battery pack provided in the embodiment of the present application includes a battery box 100 and a plurality of battery cells 200. The battery box 100 forms a accommodating cavity 101, and the battery cells 200 are arranged inside the accommodating cavity 101. Optionally, the battery cells 200 are arranged in one or more columns, and the multiple battery cells 200 in each column are arranged along a first direction (the direction indicated by the arrows ab in the figure); when the battery cells 200 are arranged in multiple columns, the multiple columns of battery cells 200 are arranged in a second direction (the direction indicated by the arrows cd in the figure). In this embodiment, the battery pack includes two columns of battery cells 200, and each column of battery cells 200 includes four battery cells 200. In other embodiments, the number and arrangement of the battery cells 200 can be adjusted as needed.

[0043] Figure 2 FIG. 2 is a schematic diagram of a battery cell 200 in one embodiment of the present application. Figure 2 As shown, in this embodiment, the battery cell 200 is a prismatic battery. The battery cell 200 has a top surface, a bottom surface, and four side surfaces. The terminal of the battery cell 200 is protruding from the top surface, and the pressure relief vent 210 is provided on the bottom surface of the battery cell 200. The pressure relief vent 210 is provided with a pressure relief valve 220. The pressure relief valve 220 can release pressure when the pressure inside the battery cell 200 reaches a threshold, allowing the pressure inside the battery cell 200 to be released outward through the pressure relief vent 210. The four side surfaces of the battery cell 200 include two large surfaces and two small surfaces. The area of ​​the large surface is larger than the area of ​​the small surface. The large surfaces of two adjacent battery cells 200 in the same row face each other.

[0044] Figure 3 This is a schematic diagram of a battery box 100 in an embodiment of the present application at a first viewing angle; Figure 4 FIG. 1 is a schematic diagram of a battery box 100 in a second viewing angle according to an embodiment of the present application. Figures 3 and 4 As shown, the battery box 100 provided in this application includes a box body and a bottom guard plate 120 arranged on the outside of the bottom of the box body. The box body includes a liquid-cooled bottom plate 110 and a side plate 130. The side plate 130 and the liquid-cooled bottom plate 110 enclose a receiving chamber 101 for accommodating battery cells 200. The side plate 130 is provided with a liquid inlet pipe 161 and a liquid outlet pipe 162. The liquid inlet pipe 161 is used to supply refrigerant to the liquid-cooled bottom plate 110, and the liquid outlet pipe 162 can collect the refrigerant flowing out of the liquid-cooled bottom plate 110. The refrigerant can be water, oil, or other flowing medium that can absorb heat.

[0045] Figure 5This is a schematic diagram of a liquid cooling base plate 110 according to an embodiment of the present application; Figure 6 This is a first cross-sectional view of a battery box 100 in one embodiment of the present application; Figure 7 for Figure 6 The enlarged view of the local VII. Figures 5 to 7 As shown, the liquid-cooling base plate 110 and the bottom guard plate 120 are spaced apart to form a first exhaust cavity 124. The liquid-cooling base plate 110 is provided with a liquid-cooling channel 116 and a buffer cavity 113 that are not connected to each other. The liquid-cooling base plate 110 is provided with a liquid inlet 1112 and a liquid outlet 1113 that are connected to the liquid-cooling channel 116. The refrigerant can enter the liquid-cooling channel 116 of the liquid-cooling base plate 110 through the liquid inlet 1112, absorb the heat emitted from the bottom of the battery cell 200 in the liquid-cooling channel 116, and then flow out of the liquid-cooling channel 116 through the liquid outlet 1113. The buffer cavity 113 has a first opening 1111 that is connected to the accommodating cavity 101 and a second opening 1121 that is connected to the first exhaust cavity 124. The first opening 1111 is used to receive the spray ejected when the battery cell 200 is depressurized.

[0046] Because the liquid-cooled baseplate 110 is provided with a buffer chamber 113, when a battery cell 200 experiences pressure relief due to an abnormal condition, the liquid-cooled baseplate 110 can absorb and contain the material ejected from the battery cell 200 through the buffer chamber 113, preventing the material from escaping into the accommodating chamber 101 of the battery case 100 and potentially affecting other healthy battery cells 200 and circuits. Furthermore, the buffer chamber 113 has a certain capacity, preventing the material from strongly impacting the bottom guard plate 120. This allows the high-pressure gas ejected from the battery cell 200 to diffuse and reduce pressure to a certain extent after entering the buffer chamber 113 through the first opening 1111, before entering the first exhaust chamber 124 through the second opening 1121.

[0047] In this embodiment, the liquid cooling base plate 110 supports and cools the battery cells 200, and also contains and temporarily stores the ejected material when the battery cells 200 are depressurized. Therefore, the liquid cooling base plate 110 can ensure that the battery cells 200 have better structural reliability, performance, and safety. In order to improve the cooling effect on the battery cells 200, in this embodiment, the battery pack also includes a cooling plate 300 (see Figure 1), the cooling plate 300 is arranged between two adjacent battery cells 200 and is in contact with the two adjacent battery cells 200. Specifically, the cooling plate 300 is in contact with the large surface of the adjacent battery cells 200. A liquid inlet pipe 161 and a liquid outlet pipe 162 are provided on the side plate 130. The liquid inlet pipe 161 is connected to the liquid inlet 1112 and the cooling plate 300, so that the liquid inlet pipe 161 can simultaneously supply refrigerant to the liquid-cooled bottom plate 110 and the cooling plate 300; the liquid outlet pipe 162 is connected to the liquid outlet 1113 and the cooling plate 300, so that the liquid outlet pipe 162 can collect refrigerant from the liquid-cooled bottom plate 110 and the cooling plate 300 and send it out of the battery box 100. Specifically, the liquid inlet pipe 161 can be connected to the liquid inlet 1112 and the cooling plate 300 through a pipeline and a tee pipe fitting, and the liquid outlet pipe 162 can be connected to the liquid outlet 1113 and the cooling plate 300 through a pipeline and a tee pipe fitting.

[0048] In this embodiment, reference Figure 7 The liquid-cooling base plate 110 includes a first plate 111 and a second plate 112 spaced apart in the thickness direction thereof. A liquid-cooling channel 116 and a buffer cavity 113 are formed between the first plate 111 and the second plate 112. A first opening 1111 is provided in the first plate 111, and a second opening 1121 is provided in the second plate 112. A blocking rib 114 is provided between the first plate 111 and the second plate 112. At least a portion of the blocking rib 114 serves to separate the liquid-cooling channel 116 from the buffer cavity 113. The first plate 111 is closer to the accommodating cavity 101 than the second plate 112. The liquid inlet 1112 and the liquid outlet 1113 are both provided on the first plate 111. The blocking rib 114 can be connected to the first plate 111 and the second plate 112 by welding. The blocking rib 114 can also be integrally formed with one of the first plate 111 and the second plate 112 and welded to the other of the first plate 111 and the second plate 112. The blocking rib 114 can also be integrally formed with the first plate 111 and the second plate 112 at the same time to improve the overall structural strength so as to support the battery cell 200.

[0049] Optionally, the liquid-cooling base plate 110 is provided with at least one row of first openings 1111 and at least one row of second openings 1121. The first openings 1111 and the second openings 1121 correspond one-to-one and are opposite each other in the thickness direction of the liquid-cooling base plate 110. The multiple first openings 1111 belonging to the same row are arranged along the first direction. In this embodiment, the number of first openings 1111 is equal to the number of battery cells 200 and corresponds one-to-one with the pressure relief ports 210 of the battery cells 200. Therefore, in this embodiment, the liquid-cooling base plate 110 is provided with two rows of first openings 1111, each row containing four first openings 1111. In other embodiments, the number and arrangement of the first openings 1111 and the second openings 1121 can be adjusted according to the number and arrangement of the battery cells 200. Optionally, the first openings 1111 and the second openings 1121 are consistent in shape and size. In this embodiment, the area ratio of a single second opening 1121 to a single pressure relief vent 210 is 0.35-2.25. It should be understood that if the second opening 1121 is too large, the buffering effect of the buffer cavity 113 will be reduced; if the second opening 1121 is too small, the buffer cavity 113 may be over-pressurized, affecting the proper venting of the pressure relief vent 210 of the battery cell 200. Optionally, the area ratio of the second opening 1121 to the pressure relief vent 210 is 1-1.5, with the area of ​​the second opening 1121 being greater than or equal to the area of ​​the pressure relief vent 210, to ensure both buffering effect and venting efficiency.

[0050] In this embodiment, a blocking member 140 is provided on the liquid-cooled base plate 110. The blocking member 140 blocks the first opening 1111. The blocking member 140 is used to be destroyed when the battery cell 200 is depressurized, so that the ejected material enters the buffer chamber 113 through the first opening 1111. It can be understood that when the abnormal battery cell 200 is depressurized, the high-temperature, high-pressure ejected material may remain and spread in the buffer chamber 113. By providing the blocking member 140, the high-temperature, high-pressure ejected material that has entered the buffer chamber 113 can be prevented from passing through the first opening 1111 corresponding to other normal battery cells 200, damaging the pressure relief valve 220 of the normal battery cell 200, and causing thermal runaway to spread. Therefore, by providing the blocking member 140, the risk of thermal runaway spreading can be reduced and the safety of the battery pack can be improved.

[0051] Optionally, the blocking member 140 includes a limiting portion 141, a sleeve 142, and a stop wall 143. The limiting portion 141 is protruding from the outer circumferential surface of the sleeve 142 and is located at one end of the sleeve 142. The stop wall 143 blocks the other end of the sleeve 142 to form a storage cavity with one end open within the sleeve 142. The limiting portion 141 abuts against the surface of the liquid-cooling base plate 110 facing the accommodating cavity 101 and is sealed and fixed to the liquid-cooling base plate 110 via a thermally conductive structural adhesive 150. The sleeve 142 is inserted into the first opening 1111 and extends into the buffer cavity 113, so that the storage cavity extends into the buffer cavity 113 and the opening of the storage cavity faces the accommodating cavity 101. In this embodiment, the limiting portion 141 and the sleeve 142 can ensure the reliability of the sealing member 140 installed in the first opening 1111. The storage chamber formed by the sleeve 142 can avoid the pressure relief valve 220 during pressure relief. Therefore, the sealing member 140 will not affect the opening of the pressure relief valve 220, and it is not easy to cause excessive valve opening pressure to cause thermal runaway to worsen. At the same time, the storage chamber can also have a certain buffering and containment effect on the ejected material during pressure relief, making it easier for the ejected material to enter the buffer chamber 113 for buffering. In this embodiment, the stop wall 143 is thinner than the wall thickness of the sleeve 142, and is therefore relatively weak relative to the sleeve 142. This allows the stop wall 143 to be broken through during pressure relief, and the ejected material can enter the buffer chamber 113 through the pressure relief hole and the storage chamber in sequence. Furthermore, the cross-sectional area of ​​sleeve 142 is larger than that of second opening 1121 to prevent sleeve 142 from damaging and falling through second opening 1121 into first exhaust chamber 124 during thermal runaway ejection, thereby affecting exhaust efficiency. To facilitate installation of sleeve 142, the area of ​​first opening 1111 is larger than that of second opening 1121, further increasing the volume of the storage chamber and enhancing both buffering and containment.

[0052] In this embodiment, the thermally conductive structural adhesive 150 is laid on the surface of the liquid-cooled base plate 110 facing the accommodating cavity 101, and is used to connect with the bottom of the battery cell 200. This can not only ensure the reliability of the battery cell 200 arranged on the liquid-cooled base plate 110, but also reduce the air gap and improve the heat transfer efficiency of the battery cell 200 to the liquid-cooled base plate 110. Specifically, the thermally conductive structural adhesive 150 is laid on the surface of the first plate 111 facing the accommodating cavity 101. The thermally conductive structural adhesive 150 and the limiting portion 141 of the sealing member 140 are in the same plane and are wrapped around the outer peripheral side of the limiting portion 141, and are sealed with the limiting portion 141. Therefore, the thermally conductive structural adhesive 150 can also effectively position and seal the sealing member 140, ensuring the sealing and reliability of the assembly of the sealing member 140. In addition, the limiting portion 141 of the sealing member 140 can block the thermally conductive structural adhesive 150, preventing the thermally conductive structural adhesive 150 from overflowing directly below the pressure relief hole and affecting the opening of the pressure relief valve 220. At the same time, the sealing member 140 also has a height limiting function. The thermally conductive structural adhesive 150 is applied by the glue, and then the battery cell 200 is pressed on the thermally conductive structural adhesive 150, so that the thermally conductive structural adhesive is spread out. By setting the sealing member, the battery cell 200 can directly abut the sealing member 140 when pressing the glue, thereby limiting the height of the thermally conductive structural adhesive 150 during pressing, thereby improving the uniformity of the thermally conductive structural adhesive 150.

[0053] Figure 8 This is a cross-sectional view of the liquid cooling base plate 110 in one embodiment of the present application. Figure 8 As shown, the liquid cooling channel 116 includes a plurality of sub-channels 1161 extending along a first direction, and the plurality of sub-channels 1161 are arranged in a second direction. The first direction and the second direction are perpendicular to each other and are both perpendicular to the thickness direction of the liquid cooling base plate 110. Figure 8As can be seen, the sub-channels 1161 are separated by a portion of the blocking ribs 114 (the other portion of the blocking ribs 114 is used to separate the buffer chamber 113 and the liquid-cooling channel 116). The liquid-cooling channel 116 extends in a circuitous manner to ensure that its flow path is sufficiently long and uniformly distributed in the liquid-cooling base plate 110. The buffer chamber 113 extends along a first direction and is located between the two sub-channels 1161. The ejecta disposed in the buffer chamber 113 can be cooled by the two adjacent sub-channels 1161. The liquid-cooling channel 116 also includes a transition channel 1162, which is adjacent to the buffer chamber 113 in the first direction and connects to the two sub-channels 1161 adjacent to the buffer chamber 113 in the second direction. The buffer chamber 113 and the transition channel 1162 are separated by a blocking member 115. In this embodiment, the blocking member 115 can be connected to the first plate 111, the second plate 112, and the blocking rib 114 by welding. Alternatively, the blocking member 115 can be integrally formed with one of the first plate 111 and the second plate 112 and welded to the other of the first plate 111 and the second plate 112. The provision of the blocking member 115 not only enables communication between two adjacent sub-channels 1161 but also seals one end of the buffer chamber 113, ensuring that ejected matter is discharged in the same direction and improving exhaust efficiency.

[0054] Figure 9 for Figure 6 The enlarged picture of the local IX in the figure. Figure 9 As shown, the bottom guard plate 120 is sealed and fixed to the outer periphery of the bottom wall of the side plate 130. The bottom guard plate 120 can be connected to the side plate 130 by gluing, welding, or bolting. An air inlet 132 is defined on the inner side of the bottom wall of the side plate 130. A second exhaust cavity 131 is provided in the side plate 130. The air inlet 132 connects the second exhaust cavity 131 to the first exhaust cavity 124 through the air inlet 132, providing more space and channels for exhaust, thereby reducing the risk of thermal runaway. In this embodiment, the bottom wall of the side plate 130 (i.e., forming the lower surface of the side plate 130) is defined by the inner side of the bottom wall, i.e., the side of the bottom wall of the side plate 130 that is closest to the liquid-cooled bottom plate 110, and the outer side of the bottom wall of the side plate 130 that is away from the liquid-cooled bottom plate 110. The air inlet 132 on the side plate 130 allows air to flow in the up-down direction, i.e., the ef direction. An air inlet 132 is provided on the inner side of the bottom wall of the side plate 130, and the bottom guard plate 120 is fixed on the outer side of the bottom wall of the side plate 130. This can reasonably utilize the space on the bottom wall of the side plate 130, avoid opening the air inlet 132 on the side wall of the side plate 130 to introduce thermal runaway gas into the accommodating cavity 101, so that the thermal runaway ejecta only flows from the bottom of the liquid-cooled bottom plate 110, completely isolating the thermal runaway ejecta from other normal battery cells 200, and at the same time, the limited space can also be used to achieve reliable fixation of the bottom guard plate 120.

[0055] Furthermore, an exhaust port is provided on the outer wall of the side panel 130, and the exhaust port is used to connect the second exhaust chamber 131 and the outside of the battery box 100. The exhaust port is provided with an exhaust valve 134. By providing the second exhaust chamber 131 in the side panel 130, the storage capacity of the battery box 100 for the ejected material can be increased. When the ejected material enters the buffer chamber 113 and the first exhaust chamber 124, the air pressure in the first exhaust chamber 124 will increase. The gas in the first exhaust chamber 124 can enter the second exhaust chamber 131 in the side panel 130 through the air inlet 132, thereby avoiding excessive air pressure in the first exhaust chamber 124 and improving the safety of the battery pack. In addition, the exhaust port on the side panel 130 can be used to release the ejected material and discharge it out of the battery box 100. The exhaust valve 134 can be forced to open when the air pressure in the second exhaust chamber 131 rises to a certain level, thereby releasing the gas in the second exhaust chamber 131 and reducing the air pressure in the second exhaust chamber 131, the first exhaust chamber 124, and the buffer chamber 113. The provision of an exhaust port allows for the targeted release of high-pressure gas. In other optional embodiments, the exhaust valve 134 can also be opened and closed manually or electronically.

[0056] Figure 10 This is a schematic diagram of a bottom guard plate 120 in one embodiment of the present application; Figure 11 This is a second cross-sectional view of the battery box 100 in one embodiment of the present application. Figures 9 to 11 In this embodiment, the bottom guard plate 120 is provided with a plurality of guide grooves 121 arranged along a first direction. The guide grooves 121 extend along a second direction. The plurality of guide grooves 121 correspond one-to-one with the plurality of second openings 1121 in the same column and face each other in the thickness direction of the liquid-cooling bottom plate 110. At least one end of the guide grooves 121 extends toward the air inlet 132 of the side plate 130. By providing the guide grooves 121, the airflow generated by the pressure relief can be guided along the second direction toward the air inlet 132 of the side plate 130, thereby effectively directing the gas in the first exhaust chamber 124 into the second exhaust chamber 131. Furthermore, the plurality of second openings 1121 in the same column are isolated from each other by the plurality of independent guide grooves 121. The guide grooves 121 can restrict the gas flowing therein to a certain extent, reducing its flow in the first direction. Therefore, when a battery cell 200 is depressurized, the presence of the guide groove 121 can reduce the diffusion of the gas ejected from the battery cell 200 to the bottom of other battery cells 200, and instead guide the gas to the second exhaust cavity 131 of the side plate 130 as quickly as possible, reducing the risk of thermal runaway spreading.

[0057] Optionally, both sides of the guide groove 121 adjacent to the side panels 130 in the second direction are provided with air inlets 132; alternatively, the side panels 130 adjacent to one of the two sides of the guide groove 121 in the second direction are provided with air inlets 132, thereby improving the accuracy of thermal runaway exhaust and reducing costs. In this embodiment, since there are two rows of battery cells 200, each with four cells, a total of four guide grooves 121 are provided on the bottom guard plate 120, each corresponding to the pressure relief vents 210 of two battery cells 200 in different rows. This design reduces the number of different battery cells 200 corresponding to the same guide groove 121, further preventing heat spread.

[0058] In this embodiment, adjacent flow guide grooves 121 are separated by a flow guide rib 122 protruding toward the liquid-cooling base plate 110. The distance between the top of the flow guide rib 122 and the liquid-cooling base plate 110 (specifically, the second plate 112) is 3-6 mm, and more specifically, 4-5 mm. The projection of the flow guide rib 122 on the liquid-cooling base plate 110 is located between the two second openings 1121, that is, between two second openings 1121 adjacent in the first direction. This prevents the gas in the flow guide groove 121 from diffusing along the first direction. It is understood that if the flow guide rib 122 is too far from the liquid-cooling base plate 110, the flow guide effect will be poor. If the flow guide rib 122 is too close to the liquid-cooling base plate 110, the bottom guard plate 120 may collide with the liquid-cooling base plate 110 during vibration, damaging the liquid-cooling base plate 110. Furthermore, the air pressure within the flow guide groove 121 may increase rapidly, hindering the decompression of the battery cells 200. In this embodiment, the guide ribs 122 and the guide grooves 121 are formed by stamping a plate. Providing the guide ribs 122 can also increase the strength of the bottom guard plate 120 .

[0059] In this embodiment, the inner bottom portion of the bottom wall of the side panel 130 is provided with multiple air inlets 132. The bottom guard plate 120 is provided with multiple buffer grooves 123, each corresponding to the multiple guide grooves 121. The multiple air inlets 132 correspond to the multiple buffer grooves 123. The buffer grooves 123 are located at one end of the guide grooves 121. The bottom guard plate 120 is provided with a groove to form a first exhaust cavity 124. The guide ribs 122 are located within the groove, and the sidewalls of the groove form recessed buffer grooves 123 at locations corresponding to the guide grooves 121. Specifically, one side of the buffer groove 123 in the second direction is open and faces the end of the guide groove 121. One side of the buffer groove 123 in the third direction (indicated by arrow ef in the figure) is open and faces the air inlets 132. The third direction is the thickness direction of the liquid-cooling base plate 110. In this embodiment, buffer groove 123 is opposite to air inlet 132 in the third direction, that is, located directly below air inlet 132. Simultaneously, buffer groove 123 is opposite to guide groove 121 in the second direction, allowing buffer groove 123 to guide gas directed from guide groove 121 toward air inlet 132. Furthermore, gas rises as it flows from buffer groove 123 toward air inlet 132, allowing impurities generated by thermal runaway to settle within buffer groove 123. Specifically, buffer groove 123 has a concave, arc-shaped structure, facilitating gas discharge and providing space for impurity sedimentation.

[0060] In this embodiment, a filter is provided in the first exhaust chamber 124, and the filter is used to filter the gas entering the second exhaust chamber 131 from the first exhaust chamber 124. Specifically, a filter is also provided in the second exhaust chamber 131, and the filter is used to filter the gas to be discharged from the exhaust port. For the convenience of distinction, the filter in the first exhaust chamber 124 is defined as the first filter 125, and the filter in the second exhaust chamber 131 is defined as the second filter 133. In this embodiment, the first filter 125 is provided between the buffer groove 123 and the end of the guide groove 121. The first filter 125 is used to filter the gas entering the buffer groove 123 from the guide groove 121 to prevent excessive accumulation of impurities in the buffer groove 123, resulting in poor exhaust. Optionally, the first filter 125 is a strip-shaped plate with a mesh. The first filter 125 is perpendicular to the second direction and extends along the first direction, so that one first filter 125 is separated between the four guide grooves 121 and the four buffer grooves 123. The upper end of the first filter element 125 is connected to the side plate 130 , and a gap is reserved between the lower end and the bottom guard plate 120 to avoid direct contact with the bottom guard plate 120 and thus damage to the bottom guard plate 120 .

[0061] Specifically, the first filter element 125 engages with the side plate 130. For example, the side plate 130 may be provided with a T-slot or dovetail groove, and the upper end of the first filter element 125 engages in the T-slot or dovetail groove, thereby preventing it from falling off. In addition to filtering, the first filter element 125 also provides a certain degree of support, preventing the bottom guard plate 120 from colliding with the liquid cooling base plate 110 upwards, thereby reducing the impact between the two.

[0062] Optionally, the second filter element 133 is positioned at least 10 mm above the bottom of the second exhaust cavity 131. If this distance is too small, it can easily become clogged by foreign matter. In this embodiment, the second filter element 133 is a plate with mesh holes and is parallel to the liquid-cooling base plate 110. The second exhaust port on the side plate 130 is located above the second filter element 133, that is, on the side away from the liquid-cooling base plate 110 in the third direction.

[0063] Optionally, the first filter element 125 and the second filter element 133 are both made of metal, which can ensure that they will not deform or fail at high temperatures. The material of the first filter element 125 and the second filter element 133 can be at least one of steel, copper, and aluminum. Furthermore, the filter pore size on the first filter element 125 is larger than the filter pore size on the second filter element 133. Therefore, the first filter element 125 plays a preliminary filtering role on the gas generated during pressure relief, and the second filter element 133 performs a more refined filtration, thereby ensuring that the gas discharged from the battery box 100 has a higher degree of cleanliness. Optionally, the filter pore size of the first filter element 125 is 2~6mm, and the filter pore size of the second filter element 133 is 1~4mm.

[0064] In summary, the embodiments of the present application provide a battery box 100 and a battery pack. The battery box 100 provided in the present application includes a box body and a bottom guard plate 120 disposed on the outer side of the bottom of the box body. The box body includes a liquid-cooled bottom plate 110 and a side plate 130. The side plate 130 and the liquid-cooled bottom plate 110 are spaced apart to form a first exhaust cavity 124. The liquid-cooled bottom plate 110 is provided with a liquid cooling channel 116 and a buffer cavity 113 that are not connected to each other. The liquid-cooled bottom plate is provided with a liquid inlet 1112 and a liquid outlet 1113 that are connected to the liquid cooling channel 116. The buffer cavity 113 has a first opening 1111 that is connected to the accommodation cavity 101 and a second opening 1121 that is connected to the first exhaust cavity 124. The first opening 1111 is used to receive the spray ejected when the battery cell 200 is depressurized. In the present application, the buffer chamber 113 and the liquid cooling channel 116 are integrated into the liquid cooling base plate 110, so that the liquid cooling base plate 110 can simultaneously realize the dual functions of cooling the battery cell 200 and buffering the ejecta during thermal runaway. When the high-temperature and high-pressure ejecta are ejected from the pressure relief port 210 of the battery cell 200, they can first enter the buffer chamber 113 through the first opening 1111. The buffer chamber 113 has a certain volume and can prevent a sharp increase in pressure. A first exhaust chamber 124 that is larger than the buffer chamber 113 is formed between the bottom guard plate 120 and the liquid cooling base plate 110. The gas in the buffer chamber 113 can enter the first exhaust chamber 124 through the second opening 1121 to further release the pressure. The buffer chamber 113 can temporarily accommodate the ejecta, which can not only alleviate the high pressure, but also prevent the high-temperature and high-pressure ejecta from directly impacting the bottom guard plate 120, thereby improving the safety of the entire battery pack.

[0065] The battery pack provided in the present application includes the above-mentioned battery box 100 and a battery cell 200 disposed in the battery box 100 . The battery pack has better safety.

[0066] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the protection scope of the present application.

Claims

1. A battery box, characterized in that: The invention comprises a box body and a bottom guard plate (120) arranged on the outer side of the bottom of the box body, wherein the box body comprises a liquid cooling bottom plate (110) and a side plate (130), wherein the side plate (130) and the liquid cooling bottom plate (110) enclose a receiving cavity (101) for receiving a battery cell (200), wherein the liquid cooling bottom plate (110) and the bottom guard plate (120) are spaced apart to form a first exhaust cavity (124), and wherein the liquid cooling bottom plate (110) is provided with liquid cooling channels (116) which are not connected to each other. ) and a buffer chamber (113), the liquid cooling base plate (110) is provided with a liquid inlet (1112) and a liquid outlet (1113) communicating with the liquid cooling channel (116), the buffer chamber (113) having a first opening (1111) communicating with the accommodating chamber (101) and a second opening (1121) communicating with the first exhaust chamber (124), the first opening (1111) being used to receive ejected matter ejected when the battery cell (200) is depressurized; A blocking member (140) is provided on the liquid cooling base plate (110), the blocking member (140) blocks the first opening (1111), and the blocking member (140) is configured to be destroyed when the battery cell (200) is depressurized, so that the ejected matter enters the buffer chamber (113) through the first opening (1111); The blocking member (140) includes a limiting portion (141), a sleeve (142) and a stop wall (143), wherein the limiting portion (141) is protruding from the outer peripheral surface of the sleeve (142) and is located at one end of the sleeve (142), and the stop wall (143) blocks the other end of the sleeve (142) to form a storage cavity with one end open in the sleeve (142), and the limiting portion (141) is in contact with the surface of the liquid-cooling base plate (110) facing the accommodating cavity (101) and is connected to the liquid-cooling base plate (110) through a heat-conducting structural adhesive (150). 110) is sealed and fixed, the thermal conductive structural adhesive (150) and the limiting portion (141) are in the same plane and wrapped around the outer peripheral side of the limiting portion (141), the blocking member (140) is used to abut the battery cell (200) when the battery cell (200) is pressed on the thermal conductive structural adhesive (150), and the sleeve (142) is inserted into the first opening (1111) and extends into the buffer cavity (113), so that the storage cavity extends into the buffer cavity (113) and the opening of the storage cavity faces the accommodating cavity (101).

2. The battery box according to claim 1, characterized in that: The bottom guard plate (120) is sealed and fixed to the outer periphery of the bottom wall of the side plate (130); an air inlet (132) is provided on the inner side of the bottom wall of the side plate (130); a second exhaust cavity (131) is provided in the side plate (130); the second exhaust cavity (131) is communicated with the first exhaust cavity (124) through the air inlet (132); An exhaust port is provided on the outer wall of the side plate (130), the exhaust port being used to connect the second exhaust cavity (131) and the outside of the battery box (100), and the exhaust port is provided with an exhaust valve (134).

3. The battery box according to claim 2, characterized in that: The liquid cooling base plate (110) is provided with at least one row of the first openings (1111) and at least one row of the second openings (1121), the first openings (1111) and the second openings (1121) are in one-to-one correspondence and are opposite to each other in the thickness direction of the liquid cooling base plate (110), and the plurality of the first openings (1111) belonging to the same row are arranged along the first direction; the bottom guard plate (120) is provided with a plurality of guide grooves (121) arranged along the first direction, the plurality of the guide grooves (121) and the plurality of the second openings (1121) belonging to the same row are in one-to-one correspondence and are opposite to each other in the thickness direction of the liquid cooling base plate (110), and at least one end of the guide groove (121) extends toward the air inlet (132) of the side plate (130).

4. The battery box according to claim 3, characterized in that: The guide groove (121) extends along the second direction, a plurality of the air inlets (132) are provided on the inner side of the bottom wall of the side plate (130), and a plurality of buffer grooves (123) are provided on the bottom guard plate (120), the plurality of buffer grooves (123) correspond one-to-one to the plurality of the guide grooves (121), and the plurality of the air inlets (132) correspond one-to-one to the plurality of the buffer grooves (123); one side of the buffer groove (123) in the second direction is open and faces the end of the guide groove (121), and one side of the buffer groove (123) in the third direction is open and faces the air inlets (132); wherein the second direction is perpendicular to the first direction and the third direction, and the third direction is the thickness direction of the liquid cooling base plate (110).

5. The battery box according to claim 4, characterized in that: A filter is provided in the first exhaust cavity (124), the filter being provided between the buffer groove (123) and the end of the guide groove (121), and being used for filtering gas entering the buffer groove (123) from the guide groove (121).

6. The battery box according to any one of claims 1 to 5, characterized in that: The liquid cooling base plate (110) comprises a first plate body (111) and a second plate body (112) which are spaced apart from each other; the liquid cooling channel (116) and the buffer cavity (113) are formed between the first plate body (111) and the second plate body (112); the first opening (1111) is provided on the first plate body (111); and the second opening (1121) is provided on the second plate body (112); a blocking rib (114) is provided between the first plate body (111) and the second plate body (112); at least part of the blocking rib (114) is used to separate the liquid cooling channel (116) and the buffer cavity (113).

7. A battery pack, characterized in that: A battery box (100) comprising a plurality of battery cells (200) and any one of claims 1 to 6, wherein the battery cells (200) are provided with a pressure relief port (210), the battery cells (200) are arranged on the liquid-cooling base plate (110), and the pressure relief port (210) is opposite to the first opening (1111).

8. The battery pack according to claim 7, characterized in that: The area ratio of a single second opening (1121) to a single pressure relief port (210) is 0.35-2.25.

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