Battery packs and their electrical equipment and energy storage equipment

Abstract

The utility model provides a battery pack and its electric equipment and energy storage equipment. The battery pack includes a battery cell stack and a box. The battery cell stack is formed by stacking a plurality of soft-pack battery cells. The battery cell stack is arranged in the box. The box includes a bottom plate and a beam. The bottom plate is located at the bottom of the box. The bottom plate is constructed as a hollow structural plate with a first airflow channel formed inside. The top wall of the bottom plate has a glue-coated area and a non-glue-coated area. The battery cell stack is directly bonded to the bottom plate by a heat-conductive structural adhesive coated on the glue-coated area. The non-glue-coated area is provided with an exhaust hole, which is connected to the first airflow channel. The beam is constructed as a hollow part with a second airflow channel inside. One end of the second airflow channel is connected to the first airflow channel, and the other end is connected to the outside of the box. The technical solution of the battery pack can ensure the exhaust when the battery cell unit fails, avoid thermal runaway caused by poor exhaust, and improve the safety performance of the battery pack.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, in particular to a battery pack and its electrical equipment and energy storage equipment. Background Art

[0002] In order to improve the energy density, safety and cost-effectiveness of battery packs, CTP (Cell to Pack) technology directly groups battery cells into battery packs, eliminating additional modules and brackets, thereby reducing connectors and space occupancy between battery components.

[0003] At present, common battery cells are divided into cylindrical cells, square-shell cells and soft-pack cells according to their structures. CTP battery packs using square-shell cells have been widely promoted and used, but soft-pack cells still face a series of problems in the process of integration into CTP battery packs because they are not easy to withstand external impacts and have poor assembly properties.

[0004] In addition, under certain conditions such as overcharging, mechanical damage, and electrolyte leakage, violent exothermic reactions may occur inside some battery cells. If not properly controlled, thermal runaway events may occur. In particular, when a short circuit occurs inside the battery, the current will pass through the short circuit location to form an arc. The high temperature generated by the arc will also cause the gas inside the battery to expand and generate high pressure, which is a high-voltage arcing phenomenon. The high-voltage arcing phenomenon can aggravate the rupture and combustion of the battery and increase the severity of the thermal runaway event. Rapidly discharging the gas generated in the early stage of the exothermic reaction is an important means to prevent or delay the occurrence of thermal runaway events.

[0005] In some technical solutions for grouping soft-pack cells into battery packs, in order to fix the cell stack in the battery pack, a structural adhesive, foam adhesive or other adhesive layer can be used to directly bond and fix the cell stack. Furthermore, in order to stably fix the cell stack from all directions, the adhesive layer will also surround the cell stack. In this case, how to ensure exhaust when the cell unit fails, avoid thermal runaway caused by poor exhaust, and improve the safety redundancy performance of the battery pack are technical problems that need to be solved urgently. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a battery pack for solving the problem of poor exhaust when thermal runaway occurs in the battery cells of the prior art battery pack, so as to improve the safety performance of the battery pack.

[0007] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present application provides a battery pack, including a cell stack and a box body, the cell stack body is formed by stacking a plurality of soft-pack battery cells, the cell stack body is arranged in the box body, the box body includes a bottom plate and a beam, the bottom plate is located at the bottom of the box body, the bottom plate is constructed as a hollow structural plate with a first air flow channel formed inside, the top wall of the bottom plate has a glue-coated area and a non-glue-coated area, the cell stack body is directly bonded to the bottom plate using a thermally conductive structural glue coated on the glue-coated area, the non-glue-coated area is provided with an exhaust hole, the exhaust hole is connected to the first air flow channel, the beam is constructed as a hollow part with a second air flow channel inside, one end of the second air flow channel is connected to the first air flow channel, and the other end is connected to the outside of the box body.

[0008] The outer packaging material of the soft-pack battery cell is plastic and has a low hardness. In the glue-coated area, the bottom of the soft-pack battery cell is coated with a thermally conductive structural adhesive. The thermally conductive structural adhesive has a high strength, which can increase the stability of the battery cell stack formed by the soft-pack battery cell in the box. Therefore, compared with the glue-coated area, when a fault occurs and gas is generated, the damage of the outer packaging material is more likely to occur in the non-glue-coated area that is not coated with the thermally conductive structural adhesive. By setting exhaust holes in the non-glue-coated area of ​​the bottom plate, and then using the first airflow channel inside the bottom plate that is constructed as a hollow structural plate, the gas is discharged through the bottom plate and the beam in turn, which can effectively form an independent exhaust space to ensure the rapid discharge of gas. At the same time, the airflow channel and the high-voltage electrical area are separated to avoid the occurrence of high-voltage arcing and improve safety performance.

[0009] Optionally, the battery pack further includes a glue blocking strip, which is arranged to protrude from the bottom plate to separate the glue-coated area from the non-glue-coated area. The glue blocking strip can limit the glue-coating position and glue layer thickness, improve the consistency and stability of the bonding of the battery cell stack, prevent the thermal conductive structural glue from invading the non-glue-coated area and blocking the exhaust hole, and ensure the smooth flow of the airflow channel for exhaust.

[0010] Optionally, there are multiple rubber blocking strips, the extension direction of which is parallel to the stacking direction of the soft-pack cells in the cell stack, and the multiple rubber blocking strips are spaced apart and arranged below the middle of the cell stack. By arranging multiple rubber blocking strips spaced apart below the middle of the cell stack, an independent exhaust space is created below the middle of the cell stack, which can receive the gas generated by the soft-pack cell failure at a high throughput, and effectively separate the gas generation position and the high-voltage electrical area (such as the area around the electrode lead-out portion) at a greater distance, thereby avoiding the occurrence of high-voltage arcing and improving safety performance.

[0011] Optionally, the extension direction of the exhaust hole is perpendicular to the stacking direction of the soft-pack battery cells in the battery cell stack, and a plurality of exhaust holes are provided in the non-glue-coated area, each exhaust hole being provided corresponding to at least one soft-pack battery cell. Providing the exhaust holes in a manner corresponding to the soft-pack battery cells can improve the exhaust effect of the exhaust holes on the gas generated during a fault.

[0012] Optionally, the exhaust hole is a waist-shaped hole or a rectangular hole whose width corresponds to the thickness of the soft-pack battery cell. By setting the exhaust hole in a manner corresponding to the thickness of the soft-pack battery cell, a better correspondence can be achieved between the exhaust hole and the most likely fault exhaust position (i.e., the main body of the soft-pack battery cell), ensuring that the gas can directly enter the first airflow channel through the exhaust hole after being discharged, reducing the possibility of airflow being blocked.

[0013] Optionally, the bottom plate includes an upper plate and a lower plate, a first airflow channel is defined between the upper plate and the lower plate, and the upper plate is configured as a liquid cooling plate. Liquid cooling of the battery cell stack using the bottom plate can improve the heat dissipation performance of the battery cell stack.

[0014] Optionally, the liquid cooling plate includes: a raised portion and a flat portion, the raised portion and the flat portion are arranged alternately, the raised portion has a liquid flow channel inside, the top surface of the raised portion is higher than the top surface of the flat portion, the top surface of the raised portion is configured as a glue coating area, and the exhaust hole is provided on the flat portion. By using the flat portion between the raised portions for exhaust, the area that can be used as the exhaust area can be effectively increased. The raised portion not only serves as a liquid flow channel, but also improves the structural strength of the liquid cooling plate by forming a concave-convex structure, thereby improving the supporting strength and stability of the battery cell stack.

[0015] Optionally, the box body further includes: a top plate, which is opposite to the bottom plate, and the top plate is constructed as a liquid cooling plate, and the top plate and the battery cell stack are directly bonded and fixed by a heat-conducting structural adhesive. The top plate and the bottom plate are both liquid cooling plates, and the battery cell stack is cooled on both sides, so that the battery pack has better thermal management performance.

[0016] Optionally, the soft-pack battery cell includes a main body and an electrode lead-out portion at least arranged at one end of the main body near the beam, and the battery pack further includes a foam glue filled between the beam, the main body and the electrode lead-out portion. The foam glue can wrap the high-voltage electrical area of ​​the soft-pack battery cell, reduce the possibility of gas leakage from the high-voltage electrical area, and then guide the gas to be more inclined to be discharged from the area with obvious pressure drop and easy exhaust, that is, the non-glue-coated area, reduce the possibility of thermal runaway events, and improve safety performance.

[0017] Optionally, it further includes: a pressure relief valve, which is arranged on the beam, and the second air flow channel is connected to the outside of the box body via the pressure relief valve. The pressure relief valve can quickly release the pressure of the battery pack when the air pressure inside the battery pack reaches a certain pressure, thereby improving safety performance.

[0018] A second aspect of the present application provides an electrical device having the battery pack provided by the first aspect of the present application.

[0019] A third aspect of the present application provides an energy storage device having the battery pack provided by the first aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1An exploded view of a battery pack in some embodiments of the present invention.

[0021] Figure 2 A schematic diagram of the assembly structure of a group of battery cell stacks in a battery pack provided by the first embodiment of the utility model is shown.

[0022] Figure 3 It is a schematic diagram of the airflow direction in the base plate and the beam in the first embodiment of the utility model.

[0023] Figure 4 It is a partial schematic diagram of the beam in the first embodiment of the utility model.

[0024] Figure 5 It is a schematic diagram of the assembly relationship between the top plate, the bottom plate and the battery cell stack in the battery pack provided by the second embodiment of the present utility model.

[0025] Figure 6 It is a schematic diagram of the assembly relationship between the battery cell stack and the bottom plate obtained when the top plate and some soft-pack batteries in the battery cell stack are removed from the battery pack in the second embodiment.

[0026] Figure 7 It is a schematic diagram (stereoscopic diagram) of the battery pack in the second embodiment cut open at the main body plane of a soft-pack battery cell.

[0027] Figure 8 yes Figure 7 A partial enlarged view of .

[0028] Reference numerals:

[0029] 100-battery pack; 1-box; 10-installation space; 101-first installation space; 102-second installation space; 11-top plate; 12-lower shell; 120-bottom plate; 121-beam; 121a-side beam; 121b-middle beam; 130-glue-coated area; 131-non-glue-coated area; 140-exhaust hole; 151-first air flow channel; 152-second air flow channel; 160-first open structure; 161-second open structure; 170-rubber strip; 180-pressure relief valve; 181-opening; 190-upper plate; 191-lower plate; 192-raised portion; 193 flat plate; 2-battery cell stack; 20-soft-pack battery cell; 201-ear; 202-main body; 21-side plate; 3-thermal conductive structural glue; 4-foaming glue; 5-liquid flow channel. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] Spatially relative terms such as "upper", "lower", "bottom", "top", etc., may be used herein for convenience of description to describe the relationship of one element or feature to other elements or features shown in the drawings. It should be understood that in addition to the orientation shown in the drawings, the spatially relative terms may also include different orientations of the components in use and operation.

[0032] <Battery Pack>

[0033] refer to Figure 1 In some embodiments of the present invention, a battery pack 100 used as a power battery pack for an electric vehicle is provided. The battery pack 100 is a CTP type battery pack, including a box 1 and a battery cell stack 2. Two groups of battery cell stacks 2 can be placed in one box 1, and each group of battery cell stacks 2 is formed by stacking a plurality of soft-pack battery cells 20 along the thickness direction of the soft-pack battery cells 20. Figure 2 It is a schematic structural diagram of one group of battery cell stacks 2.

[0034] The plurality of soft-pack battery cells 20 are arranged side by side in a manner that the main planes (ie, two opposite side surfaces with larger areas of the soft-pack battery cells 20 ) correspond to each other, thereby forming a battery cell stack 2 .

[0035] Side plates 21 are provided on both sides of the cell stack 2. The side plates 21 apply a pre-tightening force inward along the stacking direction of the soft-pack cells 20 to the cell stack 2, which can squeeze to reduce the gap between the soft-pack cells 20 and make the soft-pack cells 20 stacked together more compactly.

[0036] After the battery cell stack 2 is compressed, the battery cell stack 2 is placed into a box (placed inside the box 1 ), and a thermally conductive structural adhesive 3 may be coated on a portion of the bottom of the box 1 . The thermally conductive structural adhesive 3 may be used to directly bond the entire battery cell stack 2 to the box 1 .

[0037] The box body 1 is formed by covering the top plate 11 on the lower shell 12. The lower shell 12 includes a bottom plate 120 and a beam 121. The bottom plate 120 is a rectangular panel, which is the same size and shape as the top plate 11 and is arranged at the bottom of the lower shell 12. The beam 121 is vertically arranged between the top plate 11 and the bottom plate 120, and includes a side beam 121a and a middle beam 121b. Among them, the side beam 121a is arranged at the outer edge of the bottom plate 120, in the shape of a rectangular frame, and together with the top plate 11 and the bottom plate 120, encloses an installation space. The middle beam 121b is arranged in the middle of the bottom plate 120, and divides the installation space 10 inside the box body 1 into a first installation space 101 and a second installation space 102, wherein the first installation space 101 is used to install a group of battery cell stacks 2, and the second installation space 102 is used to install another group of battery cell stacks 2. In some embodiments, an electrical connection component may be provided at the middle beam 121 b to electrically connect the two groups of battery cell stacks 2 to each other, and to supply power to the electric vehicle via output electrodes provided at the side beams 121 a.

[0038] In order to fix the battery stack 2 more stably, the foam glue 4 can be filled between the two ends of the battery stack 2 along the length direction of the soft-pack battery 20 and the beam 121. Specifically, it is filled between the electrode lead-out portion (ear 201) of the soft-pack battery 20, the main body 202 and the beam 121. Wrapping the two ends of the soft-pack battery 20 in the length direction with the foam glue 4 can reduce the risk of heat propagation between different soft-pack battery cells 20 during thermal runaway and improve safety performance.

[0039] The soft-pack battery 20 is a battery using plastic materials such as aluminum-plastic film as packaging materials, which has the advantages of light weight, non-explosion, flexible design, etc. The aluminum-plastic film can be, for example, an aluminum-plastic film including a nylon layer, an aluminum layer and a PP / CPP layer.

[0040] In some embodiments of the present invention, the size range of the soft-pack battery cell 20 used in the soft-pack CTP battery pack 100 is: length 300-700 mm, width 100-120 mm, thickness 10-20 mm. The thickness of the tab 201 is 0.2-0.6 mm, and the width is 40-80 mm.

[0041] <First Embodiment>

[0042] This embodiment provides a structure for providing a smooth airflow channel at the bottom of the battery stack 2, which is applied to the battery pack 100 in which the battery stack 2 composed of soft-pack battery cells 20 is directly bonded to the bottom plate 120. This structure can quickly discharge the gas leaking from the bottom of the battery stack 2 through the hollow bottom plate 120 and the beam 121 directly out of the battery pack 100 when the soft-pack battery cell 20 fails and produces gas.

[0043] Figure 2A schematic diagram of the assembly structure of a group of battery cell stacks 2 in a battery pack 100 provided in the first embodiment of the utility model is shown. Figure 3 It is a schematic diagram of the airflow direction in the base plate 120 and the beam 121 in the first embodiment of the utility model.

[0044] refer to Figure 2 and Figure 3 In the first embodiment of the present invention, the beam 121 and the bottom plate 120 are both configured as hollow structures to provide an air flow channel for gas to be discharged to the outside of the battery pack 100 .

[0045] Specifically, the upper surface of the bottom plate 120 includes a glue-coated area 130 and a non-glue-coated area 131 , and the battery cell stack 2 is directly bonded to the bottom plate 120 by using the thermal conductive structural glue 3 coated on the glue-coated area 130 .

[0046] The upper surface of the bottom plate 120 is provided with an exhaust hole 140 in the non-glue-coated area 131 for exhausting the gas generated when the soft-pack battery cell 20 fails. The bottom plate 120 is constructed as a hollow structural plate with a first airflow channel 151 formed inside. The first airflow channel 151 extends along the length direction of the soft-pack battery cell 20, and one end of the first airflow channel 151 extends to the end of the bottom plate 120. The beam 121 is also constructed as a hollow part, with a second airflow channel 152 inside, and the second airflow channel 152 is connected to the first airflow channel 151 and the outside of the box body 1 respectively.

[0047] The two ends of the bottom plate 120 along the extension direction of the first air flow channel 151 are first open structures 160 ( Figure 3 For the convenience of illustration, only the first open structure 160 at one end of the bottom plate 120 is shown. Figure 4 is a partial schematic diagram of beam 121. Figure 4 The end of the bottom of the beam 121 that is used to connect with the bottom plate 120, that is, one end of the second airflow channel 152, is a second open structure 161. The bottom plate 120 uses the first open structure 160 to connect with the second open structure 161 of the beam 121, so as to connect the first airflow channel 151 with the second airflow channel 152, thereby forming an airflow channel that connects the exhaust hole 140 with the outside of the box body 1.

[0048] Through the above method, the lower middle part of the battery cell stack 2 can be connected to the outside of the box body 1 through the exhaust hole 140. The exhaust hole 140 set here is more reasonably located, which can help the battery cell stack 2 to exhaust in a safer and more reasonable way. Specifically, the outer packaging material of the soft-pack battery cell 20 is plastic and has a low hardness. In the glue coating area 130, because the bottom of the soft-pack battery cell 20 is coated with a thermally conductive structural adhesive 3, the strength of the thermally conductive structural adhesive 3 is relatively high, which can increase the local strength of the battery cell stack 2. Therefore, compared with the glue coating area 130, when a fault occurs and gas is generated, the damage of the outer packaging material is more likely to occur in the non-glue coating area 131 that is not coated with the thermally conductive structural adhesive 3. By setting an exhaust hole 140 in the non-glue-coated area 131 of the bottom plate 120, and then using the first airflow channel 151 and the second airflow channel 152 to discharge the gas in sequence through the bottom plate 120 and the beam 121, an independent exhaust space can be effectively formed to ensure the rapid discharge of the gas. At the same time, the airflow channel and the high-voltage electrical area (the area adjacent to the pole ear 201) are separated to avoid the occurrence of high-voltage arcing and improve safety redundancy.

[0049] Continue to refer Figure 2 and Figure 3 It should be noted that the thermal conductive structural adhesive 3 is a kind of adhesive layer structure that has certain fluidity before curing and good structural strength and thermal conductivity after curing. The thermal conductive structural adhesive 3 is usually viscous before curing and has limited fluidity, so it needs to be flattened with external force to ensure uniform thickness and stable bonding of the battery cell stack 2 and the bottom plate 120.

[0050] In order to ensure that the thermally conductive structural adhesive 3 is kept in a specific area, i.e., the adhesive coating area 130, and does not flow freely to the non-adhesive coating area 131 during the flattening or leveling process, in this embodiment, a rubber stopper strip 170 is protruding from the surface of the bottom plate 120. The rubber stopper strip 170 extends in a direction perpendicular to the length direction of the soft-pack battery cell 20, separating the adhesive coating area 130 from the non-adhesive coating area 131. When the thermally conductive structural adhesive 3 applied to the adhesive coating area 130 flows to the rubber stopper strip 170, it will be blocked by the rubber stopper strip 170 and cannot move forward, thereby keeping the thermally conductive structural adhesive 3 in the adhesive coating area 130.

[0051] In this embodiment, the amount of the thermally conductive structural adhesive 3 applied in the adhesive coating area 130 is also strictly controlled to strictly control the adhesive layer thickness of the thermally conductive structural adhesive 3 to ensure stable contact with the bottom surface of the battery cell stack 2 and structural strength of the bonding. The adhesive strip 170 can also prevent the thermally conductive structural adhesive 3 from invading the non-adhesive coating area 131 and blocking the exhaust hole 140, thereby ensuring the smooth flow of the airflow channel for exhaust.

[0052] Specifically, in this embodiment, two rubber blocking strips 170 are arranged below the middle of the length direction of the soft-pack battery cell 20, between the battery cell stack 2 and the bottom plate 120. The two rubber blocking strips 170, which are arranged separately from each other, define an independent non-glue-coated area 131 between the outer peripheral glue-coated areas 130. The independent non-glue-coated area 131 is used as an independent exhaust space, which can receive the gas generated when the soft-pack battery cell 20 fails at a high throughput, and effectively separate the gas generation position and the high-voltage electrical area at a greater distance, thereby avoiding the occurrence of high-voltage arcing and improving safety performance.

[0053] In this embodiment, two rubber blocking strips 170 may be provided at the lower middle portion of each battery cell stack 2. However, the number of rubber blocking strips 170 is not limited thereto. In other embodiments, in addition to the two rubber blocking strips 170, rubber blocking strips 170 may also be provided at the ends of the battery cell stack 2 corresponding to the length direction of the soft-pack battery cells 20. The shape of the rubber blocking strips 170 may also be frame-shaped, column-shaped, or other forms as required.

[0054] In this embodiment, the extension direction of the exhaust hole 140 is perpendicular to the stacking direction of the soft-packed battery cells 20 in the battery cell stack 2, that is, parallel to the length direction of the soft-packed battery cells 20. In this embodiment, the exhaust hole 140 is a waist-shaped hole. In other embodiments, the exhaust hole 140 can also be a rectangular hole or an exhaust hole 140 of other shapes.

[0055] The thickness D of the soft-pack battery cell 20 is equal to the width W of the exhaust hole 140, or the width W of the exhaust hole 140 is equal to an integral multiple of the thickness D of the soft-pack battery cell 20, and the assembly and bonding position of the battery cell stack 2 can be such that, when bonding is completed, the exhaust hole 140 is directly opposite to the side of the main body 202 of one or more soft-pack battery cells 20. Since the main body 202 of the soft-pack battery cell 20 is the position where the exhaust action is most likely to occur, this arrangement can make the fault exhaust position and the exhaust hole 140 have a better correspondence, so that the soft-pack battery cell 20 is not easily hindered by the solid part between the exhaust holes 140 when the exhaust of the soft-pack battery cell 20 fails, but directly enters the first airflow channel 151 through the exhaust hole 140, thereby improving the exhaust effect.

[0056] In addition, in this embodiment, a pressure relief valve 180 is further provided at the end of the second air flow channel 152 communicating with the outside of the box body 1. The second air flow channel 152 communicates with the outside of the box body 1 via the pressure relief valve 180, and when the internal air pressure of the battery pack 100 reaches a certain pressure, the battery pack 100 can be quickly depressurized to improve safety performance.

[0057] In this embodiment, the end of the soft-pack battery cell 20 in the length direction, that is, the end with the pole ear 201, is wrapped by the foam glue 4. The foam glue 4 can wrap the high-voltage electrical area of ​​the soft-pack battery cell 20, reduce the possibility of gas leakage from the high-voltage electrical area, and then guide the gas to be more inclined to be discharged from the area with obvious pressure drop and easy exhaust, that is, the non-glue-coated area 131, reduce the possibility of thermal runaway events, and improve safety performance.

[0058] In some embodiments, the foam glue 4 may only wrap part of the tab 201, while exposing a portion of the top area of ​​the soft-pack battery cell 20, which is not wrapped by the foam glue 4. These portions not wrapped by the foam glue 4 can also serve as potential exhaust locations. In order to provide an available airflow channel for the potential exhaust location at the top, in this embodiment, an opening 181 is also provided at a position corresponding to the pressure relief valve 180 of the beam 121, and the opening 181 can connect the portion of the top of the soft-pack battery cell 20 that is not wrapped by the foam glue 4 and the pressure relief valve 180, so as to help the gas generated at the potential exhaust location at the top of the soft-pack battery cell 20 to be discharged smoothly.

[0059] In the above manner, in the battery pack 100 provided in the present embodiment, a mechanism to help exhaust the battery stack 2 is provided at the portion of the battery stack 2 that is not wrapped by the colloid structure (thermal conductive structure glue 3 / foam glue 4). Because the soft-pack battery 20 has a low hardness, the strength of the portion that is not wrapped by the colloid structure is relatively low, and thus the soft-pack battery 20 can be guided to be damaged and exhausted at these locations. With the airflow channels provided corresponding to these locations, the gas can be efficiently exhausted to the outside of the box 1. In addition, the airflow channel is separated from the high-voltage electrical area, which can avoid the occurrence of high-voltage arcing and improve safety redundancy.

[0060] It should be noted that, in some embodiments of the present invention, the beam 121 directly connected to the bottom plate 120 may be a side beam 121a, that is, the gas passes through the bottom plate 120 and the side beam 121a and is directly discharged to the outside through the pressure relief valve 180. In other embodiments, the beam 121 directly connected to the bottom plate 120 may also be a middle beam 121b, and the gas passes through the bottom plate 120 and the middle beam 121b, and then passes through the side beam 121a and the pressure relief valve 180 and is discharged to the outside of the box body 1.

[0061] <Second Embodiment>

[0062] The second embodiment of the present invention provides a battery pack 100 that uses liquid cooling to cool a battery cell stack 2 .

[0063] Figure 5 It is a schematic diagram of the assembly relationship among the top plate 11 , the bottom plate 120 and the battery cell stack 2 in the battery pack 100 provided in this embodiment. Figure 6It is a schematic diagram of the assembly relationship between the battery cell stack 2 and the bottom plate 120 obtained when the top plate 11 and some of the soft-pack battery cells 20 in the battery cell stack 2 are removed. Figure 7 yes Figure 5 The schematic diagram of the assembly relationship is a schematic diagram (stereoscopic diagram) formed by cutting open a main body plane of a soft-pack battery cell 20 . Figure 8 yes Figure 7 For the convenience of illustration, Figure 5-8 In the figure, other component structures except the top plate 11, the bottom plate 120 and the battery cell stack 2, such as the beam 121, the electrical connection structure, etc., are omitted.

[0064] refer to Figure 5 In this embodiment, two groups of battery cell stacks 2 are sandwiched between the top plate 11 and the bottom plate 120. The top plate 11 and the bottom plate 120 are plates of the same shape, which are arranged opposite to each other with the battery cell stacks 2 separated. Both the top plate 11 and the bottom plate 120 are constructed as liquid cooling plates, and are also directly bonded and fixed to the battery cell stacks 2 by thermally conductive structural adhesive 3. Both the top plate 11 and the bottom plate 120 use liquid cooling plates to perform double-sided cooling of the battery cell stacks 2, which can make the battery pack 100 have better thermal management performance. Below, for the sake of ease of introduction, only the structure of the bottom plate 120 is described. In some other embodiments, the top plate 11 and the bottom plate 120 can also be different plate-like members, and the present application does not limit this.

[0065] refer to Figure 6 The bottom plate 120 includes an upper plate 190 and a lower plate 191 , wherein the upper plate 190 is a liquid cooling plate, including a raised portion 192 and a flat portion 193 , the raised portion 192 and the flat portion 193 are alternately arranged, and the top surface of the raised portion 192 is higher than the top surface of the flat portion 193 .

[0066] The protrusion 192 has a liquid flow channel 5 inside (refer to Figure 8 ), the bottom of the battery cell stack 2 directly or indirectly abuts against the protrusion 192, so that the protrusion 192 is used to liquid-cool the bottom of the battery cell stack 2.

[0067] In this embodiment, the top surface of the protrusion 192 is configured as a glue coating area 130, and the heat conductive structural glue 3 is coated on the top surface of the protrusion 192. The battery cell stack 2 is bonded and fixed to the bottom plate 120 by the protrusion 192. Correspondingly, the exhaust hole 140 is provided on the flat plate 193. Specifically, refer to Figure 6In the stacking direction of the battery cell stack 2, a plurality of exhaust holes 140 are arranged on the top surface of each flat portion 193. Since there can be multiple flat portions 193 between the raised portions 192, the exhaust holes 140 set at the multiple flat portions 193 can effectively increase the exhaust area and improve the exhaust effect. The raised portion 192 can not only serve as a liquid flow channel 5, but also improve the structural strength of the liquid cooling plate by forming a concave-convex structure on the surface of the upper plate 190, further improving the support strength and stability of the battery cell stack 2.

[0068] refer to Figure 7 and Figure 8 A first airflow channel 151 is defined between the upper plate 190 and the lower plate 191. Specifically, a first airflow channel 151 is formed between each flat plate portion 193 and the lower plate 191, and the first airflow channel 151 connects the multiple exhaust holes 140 provided on the flat plate portion 193 to each other, and discharges the gas received at the exhaust hole 140 to the outside of the box body 1 through the beam 121 (not shown).

[0069] In the above manner, the battery pack 100 provided in this embodiment can perform double-sided liquid cooling on the battery cell stack 2, and the double-sided liquid cooling can simultaneously reduce the gas temperature during thermal runaway, making full use of the liquid cooling efficiency to reduce the harm of thermal runaway. In addition, air flow channels for gas exhaust are reserved at the top and bottom of the battery cell stack 2, and the number and exhaust area of ​​the exhaust holes 140 are large, so that the gas can be quickly discharged from the box 1 through the air flow channel, thereby improving safety performance.

[0070] It should be noted that in some embodiments of the present invention, the battery pack 100 is taken as a power battery pack 100 of an electric vehicle for explanation, but in other embodiments of the present invention, the battery pack 100 is not limited to application in this limited scenario, and can also be used in other suitable electrical equipment or energy storage equipment such as electronic equipment and energy storage power stations, and the present application does not impose any restrictions on this.

[0071] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery pack, characterized in that: include: A battery cell stack, wherein the battery cell stack is formed by stacking a plurality of soft-pack battery cells; A box body, wherein the battery cell stack is arranged in the box body, and the box body comprises: A bottom plate is located at the bottom of the box body, the bottom plate is constructed as a hollow structural plate with a first airflow channel formed therein, the top wall of the bottom plate has a glue-coated area and a non-glue-coated area, the battery cell stack is directly bonded to the bottom plate by using a thermally conductive structural glue coated on the glue-coated area, the non-glue-coated area is provided with an exhaust hole, and the exhaust hole is communicated with the first airflow channel; The beam is constructed as a hollow member having a second air flow channel inside, one end of the second air flow channel is communicated with the first air flow channel, and the other end of the second air flow channel is communicated with the outside of the box.

2. The battery pack according to claim 1, characterized in that: Also includes: The glue blocking strip is protruding from the bottom plate to separate the glue-coated area from the non-glue-coated area.

3. The battery pack according to claim 2, characterized in that: There are a plurality of rubber blocking strips, and the extending direction of the rubber blocking strips is parallel to the stacking direction of the soft-packed battery cells in the battery cell stack. The plurality of rubber blocking strips are spaced apart and arranged below the middle of the battery cell stack.

4. The battery pack according to claim 3, characterized in that: The extension direction of the exhaust hole is perpendicular to the stacking direction of the soft-pack battery cells in the battery cell stack. A plurality of the exhaust holes are provided in the non-glue-coated area, and each of the exhaust holes is arranged corresponding to at least one of the soft-pack battery cells.

5. The battery pack according to claim 4, characterized in that: The exhaust hole is a waist-shaped hole or a rectangular hole whose width corresponds to the thickness of the soft-pack battery cell.

6. The battery pack according to claim 1, wherein: The base plate includes an upper plate and a lower plate, the first air flow channel is defined between the upper plate and the lower plate, and the upper plate is configured as a liquid cooling plate.

7. The battery pack according to claim 6, characterized in that: The liquid cooling plate includes: a raised portion and a flat portion, the raised portion and the flat portion are alternately arranged, a liquid flow channel is provided inside the raised portion, the top surface of the raised portion is higher than the top surface of the flat portion, the top surface of the raised portion is configured as a glue coating area, and the exhaust hole is provided on the flat portion.

8. The battery pack according to claim 1, wherein: The box also includes: The top plate is opposite to the bottom plate, the top plate is constructed as a liquid cooling plate, and the top plate and the battery cell stack are directly bonded and fixed by a heat-conducting structural adhesive.

9. The battery pack according to any one of claims 1 to 8, characterized in that: The soft-pack battery cell includes a main body and an electrode lead-out portion at least arranged at one end of the main body close to the beam, and the battery pack also includes foam glue filled between the beam, the main body and the electrode lead-out portion.

10. The battery pack according to any one of claims 1 to 8, characterized in that: Also includes: A pressure relief valve is arranged on the beam, and the second air flow channel is communicated with the outside of the box body via the pressure relief valve.

11. An electrical device, characterized in that: A battery pack as claimed in any one of claims 1 to 10.

12. An energy storage device, characterized in that: A battery pack as claimed in any one of claims 1 to 10.

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