Battery box and battery pack

Abstract

The invention discloses a battery box and a battery pack, and relates to the technical field of batteries. The battery box comprises a box body and a bottom protection plate arranged on the outer side of the bottom of the box body, the box body comprises a liquid cooling bottom plate and side plates, and the side plates and the liquid cooling bottom plate define a containing cavity used for containing the single batteries. The liquid cooling bottom plate and the bottom protection plate are arranged in a spaced mode to form a first exhaust cavity, a liquid cooling channel and a buffer cavity which are not communicated with each other are formed in the liquid cooling bottom plate, a liquid inlet and a liquid outlet which are communicated with the liquid cooling channel are formed in the liquid cooling bottom plate, and the buffer cavity is provided with a first opening communicated with the containing cavity and a second opening communicated with the first exhaust cavity; the first opening is used for receiving an ejected object ejected during pressure relief of the battery monomer. According to the battery pack, the buffer cavity and the liquid cooling channel are integrated in the liquid cooling bottom plate, and the buffer cavity can temporarily store sprayed objects, so that high pressure can be relieved, the high-temperature and high-pressure sprayed objects can be prevented from directly impacting the bottom protection plate, and the safety of the whole battery pack is improved.

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, pressure relief ports are provided in battery cells to release the internal pressure of the battery cells in a directional manner, thereby preventing the battery cells from exploding or erupting in an uncertain direction during thermal runaway. In the related art, explosion-proof valves are provided on the battery box to discharge the gas ejected from the battery cells, thereby preventing the internal pressure of the battery box from rising too high due to the pressure relief of the battery cells, thereby posing a safety hazard. In the battery pack of the related art, the flow and discharge of thermal runaway gases are poor, and the high-temperature and high-pressure ejecta are still easy to affect the battery cells in the battery box, resulting in a high risk of heat spread and poor safety of the battery pack. Summary of the invention

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

[0004] The embodiments of the present application can be implemented as follows: In the first aspect, the present application provides a battery box, comprising a box body and a bottom guard plate arranged on the outer side of the bottom of the box body, the box body comprises a liquid-cooled bottom plate and a side plate, the side plate and the liquid-cooled bottom plate form a accommodating cavity for accommodating a battery cell, the liquid-cooled bottom plate and the bottom guard plate are spaced apart to form a first exhaust cavity, a liquid-cooled channel and a buffer cavity that are not connected to each other are arranged 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.

[0005] In an optional embodiment, a blocking piece is provided on the liquid cooling bottom plate, the blocking piece blocks the first opening, and the blocking piece is used to be destroyed when the battery cell is depressurized so that the ejected matter enters the buffer chamber through the first opening.

[0006] 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.

[0007] 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, 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; An exhaust port is provided on the outer wall of the side plate, and 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.

[0008] 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 with 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 with 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 plate.

[0009] 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.

[0010] In an optional embodiment, the guide groove extends along the second direction, a plurality of air inlets are arranged on the inner side of the bottom wall of the side plate, and a plurality of buffer grooves are arranged 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.

[0011] In an optional embodiment, a filter is provided in the first exhaust chamber, and the filter is provided between the buffer groove and the end of the guide groove, and the filter is used to filter the gas entering the buffer groove from the guide groove.

[0012] In an optional embodiment, a filter is provided in the first exhaust chamber, and the filter is used to filter the gas entering the second exhaust chamber from the first exhaust chamber.

[0013] In an optional embodiment, an exhaust port is opened on the outer wall of the side plate, and an exhaust valve is provided at the exhaust port.

[0014] In an optional embodiment, the liquid-cooled base plate includes a first plate body and a second plate body arranged at an interval, 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.

[0015] In an optional embodiment, the liquid cooling channel includes a plurality of sub-channels extending along a first direction, 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 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.

[0016] 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 bottom plate, and the pressure relief port is opposite to the first opening.

[0017] In an optional embodiment, the area ratio of the single second opening to the single pressure relief port is 0.35-2.25.

[0018] 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.

[0019] The battery box and battery pack provided by the embodiments of the present application have the following beneficial effects: The battery box provided in the present application includes a box body and a bottom guard plate arranged on the outer side of the bottom of the box body. The box body includes a liquid-cooled bottom plate and a side plate. The side plate and the liquid-cooled bottom plate form a receiving chamber for receiving a battery cell. The liquid-cooled bottom plate and the bottom guard plate are arranged at intervals to form a first exhaust chamber. The liquid-cooled bottom plate is provided with a liquid-cooled 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 connected to the liquid-cooled channel. The buffer chamber has a first opening connected to the receiving chamber and a second opening connected to the first exhaust chamber. The first opening is used to receive the ejection ejected when the battery cell is depressurized. In the present application, the buffer chamber and the liquid-cooled channel are integrated in the liquid-cooled bottom plate, so that the liquid-cooled bottom plate can simultaneously realize the two functions of cooling the battery cell and buffering the ejection ejected during thermal runaway. When the high-temperature and high-pressure ejection 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, which can avoid a sharp increase in pressure. A first exhaust cavity that is larger than the buffer cavity is formed between the bottom guard plate and the liquid cooling bottom plate. The gas in the buffer cavity can enter the first exhaust cavity through the second opening to further release the pressure. The buffer cavity can temporarily contain the ejected material, which can not only alleviate the high pressure, but also prevent the ejected material of high temperature and high pressure from directly impacting the bottom guard plate, thereby improving the safety of the entire battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is a schematic diagram of a battery pack in one embodiment of the present application; Figure 2 A schematic diagram of a battery cell in an embodiment of the present application; Figure 3 This is a schematic diagram of a battery box in an embodiment of the present application at a first viewing angle; Figure 4 This is a schematic diagram of a battery box in an embodiment of the present application at a second viewing angle; Figure 5 This is a schematic diagram of a liquid cooling base plate according to an embodiment of the present application; Figure 6 A first cross-sectional view of a battery box in one embodiment of the present application; Figure 7 for Figure 6 The enlarged view of the middle part VII; Figure 8 This is a cross-sectional view of a liquid cooling base plate in one embodiment of the present application; Fig. 9 for Figure 6 A magnified view of the middle part IX; Fig.10 This is a schematic diagram of a bottom guard plate in an embodiment of the present application; Fig.11 This is a second cross-sectional view of a battery box in one embodiment of the present application.

[0022] Icons: 100-battery box; 101-accommodation 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-flow channel; 1162-transition flow channel; 120-bottom guard plate; 121-guide groove; 122-guide rib; 123-buffer tank; 124-first exhaust chamber; 125-first filter element; 130-side plate; 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

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] 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 the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0025] 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, further definition and explanation thereof is not required in subsequent drawings.

[0026] In the description of the present application, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, it is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship in which the product of the invention is usually placed when used. It is only for the convenience of describing the present 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, and therefore cannot be understood as a limitation on the present application.

[0027] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0028] It should be noted that, in the absence of conflict, the features in the embodiments of the present application may be combined with each other.

[0029] Figure 1 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 plurality of battery cells 200 in each column are arranged along a first direction (the direction indicated by 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 arrows cd in the figure). In the present 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.

[0030] Figure 2 FIG. 2 is a schematic diagram of a battery cell 200 in an embodiment of the present application. Figure 2 As shown, in this embodiment, the battery cell 200 is a square battery. The battery cell 200 has a top surface, a bottom surface and four side surfaces. The pole of the battery cell 200 is convexly arranged on the top surface. The pressure relief port 210 is arranged on the bottom surface of the battery cell 200. The pressure relief port 210 is provided with a pressure relief valve 220. The pressure relief valve 220 can release pressure after the pressure in the battery cell 200 reaches a threshold value, so that the pressure in the battery cell 200 is released outward through the pressure relief port 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 column are opposite.

[0031] 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 in an embodiment of the present application. Figure 3 to Figure 4 As shown, the battery box 100 provided in the present application includes a box body and a bottom guard plate 120 arranged 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, and the side plate 130 and the liquid-cooled bottom plate 110 enclose a receiving chamber 101 for accommodating a battery cell 200. A liquid inlet pipe 161 and a liquid outlet pipe 162 are provided on the side plate 130, and 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.

[0032] 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 in the figure. Figures 5 to 7 As shown, the liquid-cooling bottom plate 110 and the bottom guard plate 120 are spaced apart to form a first exhaust cavity 124. The liquid-cooling bottom plate 110 is provided with a liquid-cooling channel 116 and a buffer cavity 113 which are not connected to each other. The liquid-cooling bottom plate 110 is provided with a liquid inlet 1112 and a liquid outlet 1113 which are connected to the liquid-cooling channel 116. The refrigerant can enter the liquid-cooling channel 116 of the liquid-cooling bottom plate 110 through the liquid inlet 1112, and after absorbing the heat emitted from the bottom of the battery cell 200 in the liquid-cooling channel 116, it flows out of the liquid-cooling channel 116 from the liquid outlet 1113. The buffer cavity 113 has a first opening 1111 which is connected to the accommodating cavity 101 and a second opening 1121 which is connected to the first exhaust cavity 124. The first opening 1111 is used to receive the ejected material ejected when the battery cell 200 is depressurized.

[0033] Since the liquid-cooled bottom plate 110 is provided with a buffer chamber 113, when the battery cell 200 is depressurized due to an abnormal situation, the liquid-cooled bottom plate 110 can absorb and contain the ejected matter from the battery cell 200 through the buffer chamber 113, thereby preventing the ejected matter from escaping in the receiving chamber 101 of the battery box 100, causing other normal battery cells 200 and circuits to be affected by the ejected matter. In addition, the buffer chamber 113 has a certain capacity, which can prevent the ejected matter from strongly impacting the bottom guard plate 120, so that the high-pressure gas ejected from the battery cell 200 can diffuse and reduce pressure to a certain extent after entering the buffer chamber 113 through the first opening 1111, and then enter the first exhaust chamber 124 through the second opening 1121.

[0034] In this embodiment, the liquid cooling base plate 110 has the function of supporting the battery cell 200, and also has the function of cooling the battery cell 200, and also has the function of receiving and temporarily storing the ejected material ejected when the battery cell 200 is depressurized. Therefore, the liquid cooling base plate 110 can ensure that the battery cell 200 has better structural reliability, performance and safety. In order to improve the cooling effect of the battery cell 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 bonded to the two adjacent battery cells 200. Specifically, the cooling plate 300 is bonded to 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, and the liquid inlet pipe 161 is connected with the liquid inlet 1112 and the cooling plate 300, so the liquid inlet pipe 161 can supply refrigerant to the liquid-cooled bottom plate 110 and the cooling plate 300 at the same time; the liquid outlet pipe 162 is connected with the liquid outlet 1113 and the cooling plate 300, so the liquid outlet pipe 162 can collect the 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 with the liquid inlet 1112 and the cooling plate 300 through a pipeline and a three-way pipe fitting, and the liquid outlet pipe 162 can be connected with the liquid outlet 1113 and the cooling plate 300 through a pipeline and a three-way pipe fitting.

[0035] In this embodiment, reference Figure 7 The liquid cooling bottom plate 110 includes a first plate body 111 and a second plate body 112 spaced apart in the thickness direction thereof, a liquid cooling channel 116 and a buffer cavity 113 are formed between the first plate body 111 and the second plate body 112, a first opening 1111 is provided on the first plate body 111, and a 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, and at least part of the blocking rib 114 is used to separate the liquid cooling channel 116 and the buffer cavity 113. The first plate body 111 is closer to the accommodating cavity 101 than the second plate body 112, and the liquid inlet 1112 and the liquid outlet 1113 are both provided on the first plate body 111. The blocking rib 114 can be connected to the first plate body 111 and the second plate body 112 by welding. The blocking rib 114 can also be integrally formed with one of the first plate body 111 and the second plate body 112 and welded to the other of the first plate body 111 and the second plate body 112. The blocking rib 114 can also be integrally formed with the first plate body 111 and the second plate body 112 at the same time to improve the overall structural strength so as to support the battery cell 200.

[0036] Optionally, at least one column of first openings 1111 and at least one column of second openings 1121 are provided on the liquid-cooled bottom plate 110, the first openings 1111 and the second openings 1121 correspond one-to-one and are opposite in the thickness direction of the liquid-cooled bottom plate 110, and the multiple first openings 1111 belonging to the same column are arranged along the first direction. In this embodiment, the number of the first openings 1111 is equal to the number of the battery cells 200, and corresponds one-to-one to the pressure relief ports 210 of the battery cells 200. Therefore, in this embodiment, two columns of first openings 1111 are provided on the liquid-cooled bottom plate 110, and each column contains 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 port 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 deteriorated; if the second opening 1121 is too small, the pressure in the buffer cavity 113 may be too high, affecting the normal exhaust of the pressure relief port 210 of the battery cell 200. Optionally, the area ratio of the second opening 1121 to the pressure relief port 210 is 1-1.5, and the area of ​​the second opening 1121 is greater than or equal to the area of ​​the pressure relief port 210 to ensure the buffering effect and exhaust efficiency.

[0037] In this embodiment, a plugging member 140 is provided on the liquid-cooled base plate 110, and the plugging member 140 blocks the first opening 1111. The plugging 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 and high-pressure ejected material may remain and spread in the buffer chamber 113. By providing the plugging member 140, it is possible to prevent the high-temperature and high-pressure ejected material that has entered the buffer chamber 113 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 the thermal runaway to spread. Therefore, by providing the plugging member 140, it is possible to reduce the risk of thermal runaway spreading and improve the safety of the battery pack.

[0038] Optionally, the blocking member 140 includes a limiting portion 141, a sleeve 142 and a stop wall 143. The limiting portion 141 is convexly arranged on 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, 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 through the heat-conducting 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. In this embodiment, the limiting portion 141 and the sleeve 142 can ensure the reliability of the sealing member 140 being installed in the first opening 1111, and the storage chamber formed by the sleeve 142 can avoid the pressure relief valve 220 during pressure relief, so 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, so that the ejected material can enter the buffer chamber 113 to achieve buffering. In this embodiment, the stop wall 143 is smaller than the wall thickness of the sleeve 142, so it is relatively weak relative to the sleeve 142, which allows the stop wall 143 to be broken during pressure relief, and the ejected material can enter the buffer chamber 113 through the pressure relief hole and the storage chamber in turn. Furthermore, the cross-sectional area of ​​the sleeve 142 is larger than the area of ​​the second opening 1121, so as to prevent the sleeve 142 from being damaged and falling through the second opening 1121 into the first exhaust cavity 124 and affecting the exhaust efficiency when the thermal runaway is ejected. In order to facilitate the installation of the sleeve 142, the area of ​​the first opening 1111 is larger than the area of ​​the second opening 1121, which can further increase the volume of the storage cavity and further improve the buffering and containment effects.

[0039] In this embodiment, the thermally conductive structural adhesive 150 is laid on the surface of the liquid-cooled bottom plate 110 facing the accommodating cavity 101, and is used to connect with the bottom of the battery cell 200, which can not only ensure the reliability of the battery cell 200 arranged on the liquid-cooled bottom plate 110, but also reduce the air gap and improve the heat transfer efficiency of the battery cell 200 to the liquid-cooled bottom plate 110. Specifically, the thermally conductive structural adhesive 150 is laid on the surface of the first plate body 111 facing the accommodating cavity 101. The thermally conductive structural adhesive 150 is in the same plane as the limiting portion 141 of the sealing member 140 and is wrapped around the outer peripheral side of the limiting portion 141, and is sealed and connected to 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 to prevent 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 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 the glue is pressed, thereby limiting the height of the thermally conductive structural adhesive 150 during the glue pressing and improving the uniformity of the thermally conductive structural adhesive 150.

[0040] Figure 8 FIG. 1 is a cross-sectional view of a 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, and the first direction and the second direction are perpendicular to each other and are perpendicular to the thickness direction of the liquid cooling base plate 110. Figure 8As can be seen in the figure, 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), and the liquid cooling channel 116 extends in a circuitous manner, thereby ensuring that its flow path is long enough and distributed sufficiently evenly in the liquid cooling base plate 110. The buffer chamber 113 extends along the first direction and is located between the two sub-channels 1161, and 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 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, or the blocking member 115 can be integrally formed with one of the first plate 111 and the second plate 112, and connected by welding to the other of the first plate 111 and the second plate 112. By providing the blocking member 115, not only can the communication between two adjacent sub-channels 1161 be achieved, but also one end of the buffer chamber 113 can be blocked, so as to ensure that the ejected matter can be discharged in the same direction, thereby improving the exhaust effect.

[0041] Fig. 9 for Figure 6 The enlarged picture of the local IX in the figure. Fig. 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 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 side plate 130 is provided with an air inlet 132. The second exhaust cavity 131 is connected to the first exhaust cavity 124 through the air inlet 132, thereby providing more space and channels for exhaust and reducing the risk of thermal runaway propagation. In this embodiment, the bottom wall of the side plate 130 (i.e., forming the lower surface of the side plate 130), the inner side of the bottom wall of the side plate 130, i.e., the side of the bottom wall of the side plate 130 close to the liquid cooling bottom plate 110, and the outer side of the bottom wall of the side plate 130 is the side of the bottom wall of the side plate 130 away from the liquid cooling bottom plate 110. The air inlet 132 provided on the side plate 130 allows gas to flow in the up and 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 the 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 also can utilize the limited space to realize the reliable fixation of the bottom guard plate 120.

[0042] 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 after 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 high-pressure gas can be released in a directional manner by providing an exhaust port. In other optional embodiments, the exhaust valve 134 can also be a valve that is opened or closed manually or electrically controlled.

[0043] Fig.10 This is a schematic diagram of a bottom guard plate 120 in one embodiment of the present application; Fig.11 FIG. 1 is a second cross-sectional view of a battery box 100 according to an 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 the first direction, and the guide grooves 121 extend along the second direction. The plurality of guide grooves 121 correspond to the plurality of second openings 1121 belonging to the same column one by one and are opposite to each other in the thickness direction of the liquid-cooling bottom plate 110, and at least one end of the guide groove 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 to flow along the second direction toward the air inlet 132 of the side plate 130, so that the gas in the first exhaust cavity 124 can be effectively introduced into the second exhaust cavity 131. In addition, the plurality of second openings 1121 belonging to the same column are isolated from each other by a plurality of independent guide grooves 121, and the guide grooves 121 can restrict the gas flowing therein to a certain extent, thereby 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.

[0044] Optionally, the side plates 130 adjacent to both ends of the guide groove 121 in the second direction are provided with air inlets 132; or, the side plates 130 adjacent to one end 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 columns of battery cells 200, four in each column; therefore, a total of four guide grooves 121 are provided on the bottom guard plate 120, and each guide groove 121 corresponds to the pressure relief port 210 of two battery cells 200 belonging to different columns. Such a design can reduce the number of different battery cells 200 corresponding to the same guide groove 121, further avoiding heat spread.

[0045] In this embodiment, two adjacent guide grooves 121 are separated by guide ribs 122 protruding toward the liquid cooling bottom plate 110, and the distance between the top of the guide rib 122 and the liquid cooling bottom plate 110 (specifically, the second plate body 112) is 3-6 mm, specifically, 4-5 mm. The projection of the guide rib 122 on the liquid cooling bottom plate 110 is located between the two second openings 1121, that is, between the two second openings 1121 adjacent in the first direction, and can block the gas in the guide groove 121 from diffusing along the first direction. It can be understood that if the distance between the guide rib 122 and the liquid cooling bottom plate 110 is too far, the diversion effect is not good. If the distance between the guide rib 122 and the liquid cooling bottom plate 110 is too close, the bottom guard plate 120 is easy to collide with the liquid cooling bottom plate 110 during vibration, damaging the liquid cooling bottom plate 110; and the air pressure in the guide groove 121 is easy to rise sharply, which is not conducive to the pressure relief of the battery cell 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 .

[0046] In this embodiment, a plurality of air inlets 132 are provided at the bottom of 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, and the plurality of buffer grooves 123 correspond to the plurality of guide grooves 121 one by one, and the plurality of air inlets 132 correspond to the plurality of buffer grooves 123 one by one. The buffer groove 123 is provided at one end of the guide groove 121. The bottom guard plate 120 is provided with a groove to form a first exhaust cavity 124, and the guide rib 122 is provided in the groove, and a recessed buffer groove 123 is formed on the side wall of the groove at a position corresponding to the guide groove 121. Specifically, 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 (the direction indicated by the arrow ef in the figure) is open and faces the air inlet 132. The third direction is the thickness direction of the liquid cooling bottom plate 110. In this embodiment, the buffer groove 123 is opposite to the air inlet 132 in the third direction, that is, it is located directly below the air inlet 132; at the same time, the buffer groove 123 is opposite to the guide groove 121 in the second direction, so that the buffer groove 123 can guide the gas guided by the guide groove 121 to the air inlet 132. In addition, the gas moves upward in the process of flowing from the buffer groove 123 to the air inlet 132, and impurities generated by thermal runaway in the gas can be settled in the buffer groove 123. Specifically, the buffer groove 123 is a concave arc structure, which is convenient for gas discharge and also convenient for expanding space to settle impurities.

[0047] In the present 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 the present embodiment, the first filter 125 is provided between the end of the buffer groove 123 and the guide groove 121, and the first filter 125 is used to filter the gas entering the buffer groove 123 from the guide groove 121, so as to avoid excessive accumulation of impurities in the buffer groove 123 causing poor exhaust. Optionally, the first filter 125 is a strip plate with a mesh, and 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 four guide grooves 121 and 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 damaging the bottom guard plate 120 .

[0048] Specifically, the first filter element 125 is engaged with the side plate 130. For example, a T-shaped groove or a dovetail groove is provided on the side plate 130, and the upper end of the first filter element 125 is engaged with the T-shaped groove or the dovetail groove, so it is not easy to fall off. In addition to filtering, the first filter element 125 can also play a certain degree of supporting role, preventing the bottom guard plate 120 from colliding upward with the liquid cooling bottom plate 110, and reducing the slapping between the two.

[0049] Optionally, the second filter element 133 is disposed more than 10 mm above the bottom of the second exhaust cavity 131. If the spacing is too small, it is easy to be blocked by foreign matter. In this embodiment, the second filter element 133 is a plate with meshes, and the second filter element 133 is parallel to the liquid cooling bottom 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 bottom plate 110 in the third direction.

[0050] 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 selected from at least one of steel, copper, and aluminum. Furthermore, the filter hole diameter on the first filter element 125 is larger than the filter hole diameter 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 filtering, thereby ensuring that the gas discharged from the battery box 100 has a higher degree of cleanliness. Optionally, the filter hole diameter of the first filter element 125 is 2~6mm, and the filter hole diameter of the second filter element 133 is 1~4mm.

[0051] In summary, the embodiment of the present application provides 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 arranged 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 arranged at intervals to form a first exhaust cavity 124. The liquid-cooled bottom plate 110 is provided with a liquid-cooled 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-cooled channel 116. The buffer cavity 113 has a first opening 1111 connected to the accommodating cavity 101 and a second opening 1121 connected to the first exhaust cavity 124. The first opening 1111 is used to receive the ejected material 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 two functions of cooling the battery cell 200 and buffering the ejection during thermal runaway. When the high-temperature and high-pressure ejection is ejected from the pressure relief port 210 of the battery cell 200, it can first enter the buffer chamber 113 through the first opening 1111. The buffer chamber 113 has a certain volume and can avoid 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 ejection, which can not only alleviate the high pressure, but also prevent the high-temperature and high-pressure ejection from directly impacting the bottom guard plate 120, thereby improving the safety of the entire battery pack.

[0052] 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 , and the battery pack has better safety.

[0053] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within 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 outside the bottom of the box body, the box body comprises a liquid cooling bottom plate (110) and a side plate (130), the side plate (130) and the liquid cooling bottom plate (110) enclose a receiving cavity (101) for receiving a battery cell (200), the liquid cooling bottom plate (110) and the bottom guard plate (120) are arranged at intervals to form a first exhaust cavity (124), and 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 bottom plate (110) being provided with a liquid inlet (1112) and a liquid outlet (1113) connected to the liquid cooling channel (116), the buffer chamber (113) having a first opening (1111) connected to the accommodating chamber (101) and a second opening (1121) connected to the first exhaust chamber (124), the first opening (1111) being used to receive ejected matter ejected when the battery cell (200) is depressurized.

2. The battery box according to claim 1, characterized in that: A blocking piece (140) is provided on the liquid cooling bottom plate (110), the blocking piece (140) blocks the first opening (1111), and the blocking piece (140) is used 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).

3. The battery box according to claim 2, characterized in that: The blocking member (140) comprises a limiting portion (141), a sleeve (142) and a stop wall (143); 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); 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); the limiting portion (141) abuts against a 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) by means of a heat-conducting 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).

4. 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).

5. The battery box according to claim 4, characterized in that: The liquid cooling bottom 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) correspond one-to-one with the second openings (1121) and are opposite to each other in the thickness direction of the liquid cooling bottom plate (110); a plurality of the first openings (1111) belonging to the same row are arranged along a first direction; the bottom guard plate (120) is provided with a plurality of guide grooves (121) arranged along the first direction; the plurality of guide grooves (121) correspond one-to-one with the plurality of the second openings (1121) belonging to the same row and are opposite to each other in the thickness direction of the liquid cooling bottom plate (110); at least one end of the guide groove (121) extends toward the air inlet (132) of the side plate (130).

6. The battery box according to claim 5, characterized in that: The guide groove (121) extends along the second direction, a plurality of air inlets (132) are arranged on the inner side of the bottom wall of the side plate (130), a plurality of buffer grooves (123) are arranged on the bottom guard plate (120), the plurality of buffer grooves (123) correspond one-to-one to the plurality of guide grooves (121), and the plurality of air inlets (132) correspond one-to-one to the plurality of 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 inlet (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 bottom plate (110).

7. The battery box according to claim 6, 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 the filter being used to filter the gas entering the buffer groove (123) from the guide groove (121).

8. The battery box according to any one of claims 1 to 7, characterized in that: The liquid cooling base plate (110) comprises a first plate body (111) and a second plate body (112) which are arranged at an interval, 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 arranged on the first plate body (111), and the second opening (1121) is arranged on the second plate body (112); a blocking rib (114) is arranged between the first plate body (111) and the second plate body (112), and at least a part of the blocking rib (114) is used to separate the liquid cooling channel (116) and the buffer cavity (113).

9. A battery pack, characterized in that: A battery box (100) comprising a plurality of battery cells (200) and any one of claims 1 to 8, wherein the battery cells (200) are provided with a pressure relief port (210), the battery cells (200) are arranged on the liquid cooling bottom plate (110), and the pressure relief port (210) is opposite to the first opening (1111).

10. The battery pack according to claim 9, characterized in that: The area ratio of a single second opening (1121) to a single pressure relief opening (210) is 0.35-2.25.

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