Power battery pack and electric vehicle

Abstract

The utility model relates to a power battery pack, and provides a power battery pack and an electric vehicle, a shell cover of a battery module in the power battery pack faces upwards and is opposite to a box cover, each battery cell in the battery module is communicated with a battery cell smoke exhaust hole in the shell cover through a battery cell smoke exhaust channel, and the battery cell smoke exhaust holes are longitudinally arranged in multiple columns; the smoke collecting pipelines arranged below the box cover comprise longitudinal pipelines and transverse pipelines, one longitudinal pipeline is arranged above each column of battery cell smoke exhaust holes, and the bottom surface of each longitudinal pipeline is in sealing fit with the battery module shell cover and covers the corresponding column of battery cell smoke exhaust holes; and the bottom of each longitudinal pipeline is provided with a smoke inlet hole which is correspondingly communicated with each battery core smoke exhaust hole below the longitudinal pipeline. According to the utility model, heat transferred to other battery modules during thermal runaway is reduced by arranging the flue gas collecting pipeline, so that the safety of the battery is improved.

Description

Technical Field

[0001] The utility model relates to a power battery, and more specifically, to a power battery pack and an electric vehicle. Background Art

[0002] Electric vehicles use battery systems to provide energy, and the battery system includes one or more power battery packs. A single power battery pack contains multiple battery modules.

[0003] In the related art, in order to prevent the high-temperature smoke and solid particles ejected from the battery cells from spreading in the battery module, a battery cell exhaust duct is set in the battery module, and the pressure relief valve of each battery cell is connected to the outside of the module shell through the battery cell exhaust duct, so that the high-temperature smoke and solid particles ejected from the battery cell with thermal runaway are discharged to the outside of the battery module. A smoke collection chamber is set in the box of the power battery pack, and the smoke collection chamber is connected to each battery cell exhaust duct outside the battery module, so that the high-temperature smoke and solid particles discharged from the battery cell exhaust duct are discharged to the outside of the battery pack.

[0004] In the power battery pack, the battery module is installed in the box of the electric box. The outlet of the battery module's cell exhaust duct is located on the top surface, opposite to the box cover of the electric box. The gap between the top of the battery module and the box cover of the electric box becomes a smoke collection chamber. An explosion-proof valve is installed on the box cover. When the high-temperature smoke and particles ejected by the battery cell due to thermal runaway enter the smoke collection chamber through the battery cell exhaust duct, when the pressure of the smoke collection chamber reaches a predetermined value, the explosion-proof valve opens to discharge the smoke outward.

[0005] The smoke collection chamber is located above all battery modules. When the smoke collection chamber is filled with high-temperature smoke and particles, the high-temperature smoke and particles contact the entire top surface of all battery modules, which may affect other battery modules and cause thermal runaway of the battery cells therein. Utility Model Content

[0006] The technical problem to be solved by the utility model is that the smoke collecting chamber above the battery module in the existing power battery pack has a great influence on all battery modules when some battery cells have thermal runaway, and a power battery pack and an electric vehicle are provided.

[0007] The utility model provides a technical solution to achieve its purpose as follows: a power battery pack is provided, comprising an electric box and a plurality of battery modules; the electric box comprises a box body and a box cover, each of the battery modules is arranged in the box body, a battery cell smoke exhaust hole is provided on the shell cover of each of the battery modules, each of the battery cell smoke exhaust holes is connected to the battery cell pressure relief valve of each battery cell below the shell cover through a battery cell smoke exhaust duct, and the shell cover is arranged upward and opposite to the box cover; each of the battery cell smoke exhaust holes is arranged in multiple rows longitudinally; a smoke collecting pipe capable of exhausting to the outside through an explosion-proof valve is arranged below the box cover, the smoke collecting pipe comprises a longitudinal pipe and a transverse pipe connecting the longitudinal pipes, one of the longitudinal pipes is arranged above each row of the battery cell smoke exhaust holes, the bottom surface of each of the longitudinal pipes is sealed and fitted with the shell cover of the battery module and covers the battery cell smoke exhaust holes of the corresponding row, and a smoke inlet hole correspondingly connected to each of the battery cell smoke exhaust holes below the longitudinal pipe is provided at the bottom of each of the longitudinal pipes.

[0008] In the power battery pack of the utility model, the smoke collecting pipe is composed of a square tube.

[0009] In the power battery pack of the utility model, the box cover includes an upper cover plate and a lower cover plate whose edges are fixedly connected to the upper cover plate. The lower cover plate is provided with a plurality of longitudinal grooves with a square cross-section and recessed downward, and transverse grooves connecting the longitudinal grooves to each other. The tops of the longitudinal grooves and the transverse grooves are sealed, fitted and fixedly connected to the bottom surface of the upper cover plate to form the smoke collecting pipe. The explosion-proof valve is installed on the upper cover, and the explosion-proof valve can also be arranged on the side wall of the box body, and is connected to the smoke collecting pipe by arranging pipelines in the box body.

[0010] In the power battery pack of the utility model, the battery cell smoke exhaust duct is composed of a heat-resistant tube whose two ends are respectively connected to the battery cell pressure relief valve and the battery cell smoke exhaust hole, and a one-way valve is provided in the heat-resistant tube for unidirectional conduction from the battery cell pressure relief valve to the battery cell smoke exhaust hole.

[0011] In the power battery pack of the utility model, a heat-resistant insulating pad is arranged between the shell cover and the battery cell, and the two back sides of the heat-resistant insulating pad are respectively sealed and connected to the shell cover and the battery cell, and the heat-resistant insulating pad is provided with a smoke exhaust through hole constituting the smoke exhaust duct of the battery cell.

[0012] In the power battery pack of the utility model, the heat-resistant insulating pad comprises a first insulating pad bonded to the battery cell and a second insulating pad bonded to the shell cover, and an information collection circuit board is sandwiched between the first insulating pad and the second insulating pad.

[0013] In the power battery pack of the utility model, a one-way valve that conducts one-way to the outside is arranged in the battery cell smoke exhaust hole, and the one-way valve includes a valve sheet arranged in the battery cell smoke exhaust hole, and the valve sheet can be attached to the heat-resistant insulating pad and cover and close the end of the smoke exhaust hole, and the valve sheet is connected to the shell cover at its edge through an elastic connecting part.

[0014] In the power battery pack of the utility model, a partition whose lower side is bonded to the shell cover is arranged on the upper side of the battery module, and the partition is provided with valve through holes at the position above each of the battery cell smoke exhaust holes; the valve through holes are slightly larger than the battery cell smoke exhaust holes, and a one-way valve is arranged therein for unidirectional conduction from the battery cell smoke exhaust holes to the outside; the one-way valve includes a valve sheet arranged in the valve through hole, the valve sheet can be bonded to the shell cover and cover and close the battery cell smoke exhaust holes, and the valve sheet is connected to the partition at its edge through an elastic connecting portion.

[0015] In the power battery pack of the utility model, the valve plate is provided with an air pressure balancing hole communicating with two sides of the valve plate.

[0016] The utility model provides a technical solution to achieve its purpose: an electric vehicle is provided, including a battery system, wherein the battery system includes the aforementioned power battery pack.

[0017] Compared with the prior art, in the power battery pack of the utility model, if a battery cell in a battery module has thermal runaway, the high-temperature flue gas and particles ejected therefrom are discharged through the battery cell exhaust duct and the flue gas collecting duct. Since the flue gas collecting duct is in the form of a pipe, its contact area with the battery module is small, and when it is filled with high-temperature flue gas, the impact on other battery modules is small. Moreover, since the volume of the flue gas collecting duct is relatively small, the amount of flue gas is small when it is filled with high-temperature flue gas, and the heat is also less, so the impact of the high-temperature flue gas on other battery modules is also small, and the safety of the battery pack is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the appearance structure of the power battery pack of the utility model.

[0019] Figure 2 It is a schematic diagram of the unpacking state of the power battery pack of the utility model.

[0020] Figure 3 It is a schematic diagram of the box cover structure of the power battery pack of the utility model.

[0021] Figure 4 yes Figure 1 A partial enlarged view of point A in the middle.

[0022] Figure 5 It is a structural schematic diagram of the smoke collecting duct in the power battery pack of the utility model.

[0023] Figure 6 It is a structural schematic diagram of a battery module in a power battery pack of the utility model.

[0024] Figure 7 It is a schematic diagram of the structure inside the battery module in the power battery pack of the utility model.

[0025] Figure 8 It is a schematic diagram of the exploded structure of the battery module in the power battery pack of the utility model.

[0026] Fig. 9 It is a structural schematic diagram of a battery cell in a power battery pack of the utility model.

[0027] Fig.10 It is a schematic diagram of the shell cover structure of the battery module in the power battery pack of the utility model.

[0028] Fig.11 yes Fig.10 A local enlarged schematic diagram of point B in the middle.

[0029] Fig.12 It is a schematic diagram of the cross-sectional structure of the smoke exhaust duct of the battery cell in the power battery pack of the utility model.

[0030] Fig.13 It is a structural schematic diagram of another structure of the one-way valve in the power battery pack of the utility model.

[0031] Fig.14 This is another structural schematic diagram of the power battery pack of the utility model.

[0032] Fig.15 This is another schematic diagram of the arrangement structure of the one-way valve in the power battery pack of the utility model.

[0033] Fig.16 yes Fig.14 A partial enlarged schematic diagram of point C in the middle.

[0034] Fig.17 It is a schematic diagram of the framework of the electric vehicle of the utility model.

[0035] Parts names and serial numbers in the figure:

[0036] Battery module 100 , power battery pack 200 , battery system 300 , control system 400 , motor system 500 .

[0037] Module shell 10 , shell body 11 , shell cover 12 , shell cover plate 121 , shell cover skirt 122 , battery cell smoke exhaust hole 1211 .

[0038] Battery cell 20 , electrode arrangement surface 21 , positive electrode 22 , negative electrode 23 , battery cell pressure relief valve 24 .

[0039] Heat-resistant insulating pad 30 , smoke exhaust through hole 31 , first through hole 311 , second through hole 312 , third through hole 313 , first insulating pad 32 , second insulating pad 33 , battery cell smoke exhaust duct 34 .

[0040] Information collection circuit board 40.

[0041] One-way valve 50 , valve plate 51 , elastic connecting portion 52 , and air pressure balance hole 53 .

[0042] Longitudinal square tube 61 , transverse square tube 62 , and side beam 63 .

[0043] Partition plate 70 and valve through hole 71.

[0044] Electric box 210 , box body 211 , box cover 212 , explosion-proof valve 213 , upper cover plate 214 , lower cover plate 215 , smoke collecting pipe 216 , longitudinal groove 2161 , transverse groove 2162 , and smoke inlet hole 2163 . DETAILED DESCRIPTION

[0045] The specific implementation scheme is described below with reference to the accompanying drawings.

[0046] like Figures 1 to 6 As shown, in this embodiment, the power battery pack 200 includes a battery box 210 and a plurality of battery modules 100 .

[0047] The electric box 210 includes a box body 211 and a box cover 212 . Each battery module 100 is arranged in the box body 211 , and the shell cover 12 of the battery module 100 is arranged upward and opposite to the box cover 212 . Each battery cell 20 in each battery module 100 is connected to its corresponding battery cell smoke exhaust hole 1211 on the shell cover 12 through its own battery cell smoke exhaust duct 34, and each battery cell smoke exhaust hole 1211 is arranged in multiple rows vertically; a smoke collecting pipe 216 that can exhaust to the outside through an explosion-proof valve 213 is arranged below the box cover 212, and the smoke collecting pipe 216 includes a longitudinal pipe and a transverse pipe connecting each longitudinal pipe, and a longitudinal pipe is arranged above each row of battery cell smoke exhaust holes 1211, and the bottom surface of each longitudinal pipe is sealed and fitted with the shell cover 12 of the battery module 100 and covers the battery cell smoke exhaust holes 1211 of the corresponding row, and a smoke inlet hole 2163 is provided at the bottom of each longitudinal pipe, which is correspondingly connected to the battery cell smoke exhaust holes 1211 below it.

[0048] like Figure 1 Figure 2 As shown, the electric box 210 includes a box body 211 and a box cover 212 . The box cover 212 is fixed to the box body 211 by bolts to close the opening of the box body 211 to form a closed space for accommodating the battery module 100 .

[0049] A plurality of battery modules 100 are arranged in the box body 211. The battery module 100 includes a plurality of battery cells 20 arranged in the module shell 10. A battery cell smoke exhaust hole 1211 is provided on the shell cover 12 of the module shell 10. Each battery cell smoke exhaust hole 1211 corresponds to a battery cell 20. The battery cell pressure relief valve 24 of each battery cell 20 is connected to the corresponding battery cell smoke exhaust hole 1211 through the respective battery cell smoke exhaust duct 34.

[0050] like Figure 6 As shown, two rows of battery cells are arranged in the battery module 100 , and accordingly, on the shell cover 12 of the battery module 100 , the battery cell smoke exhaust holes 1211 are arranged in two vertical rows.

[0051] like Figure 2 As shown, the shell cover of each battery module 100 faces upwards, opposite to the box cover 212 of the electrical box 210. Multiple battery modules 100 are installed in the electrical box 210, and the battery cell smoke exhaust holes 1211 on the shell cover 12 of each battery module 100 are arranged in multiple rows.

[0052] like Figure 3 As shown, the box cover 212 includes an upper cover plate 214 and a lower cover plate 215 fixedly connected to the upper cover plate 214 at the edges thereof. The lower cover plate 215 is provided with a plurality of longitudinal grooves 2161 with a square cross section and concave downwards and transverse grooves 2162 connecting the longitudinal grooves 2161 to each other. The number of longitudinal grooves 2161 corresponds to the number of columns of the battery cell smoke exhaust holes 1211. The bottom of the longitudinal grooves 2161 is provided with smoke inlet holes 2163 corresponding to the battery cell smoke exhaust holes 1211 on the shell cover 12. The tops of the longitudinal grooves 2161 and the transverse grooves 2162 are sealed, fitted and fixedly connected to the bottom surface of the upper cover plate 214 to form a smoke collection duct 216.

[0053] like Figure 4 As shown, after the box cover 212 is connected to the box body 211, the bottom surface of the longitudinal groove 2161 fits against the upper surface of the shell cover 12 of the battery module 100, and covers the battery cell smoke exhaust holes 1211 on the shell cover 12, and the smoke inlet holes 2163 on the longitudinal groove 2161 are connected to the battery cell smoke exhaust holes 1211 one by one.

[0054] like Figure 2 Figure 3 As shown, four explosion-proof valves 213 are fixedly installed on the box cover 212 , and each explosion-proof valve 213 is communicated with the longitudinal groove 2161 .

[0055] When thermal runaway occurs in the battery cell 20, the battery cell 20 will spray a large amount of high-temperature smoke and particles from its battery cell pressure relief valve 24. The high-temperature smoke and particles sprayed from the battery cell pressure relief valve 24 enter the smoke collecting pipe 216 through the battery cell smoke exhaust duct 34, the battery cell smoke exhaust hole 1211 on the shell cover 12, and the smoke inlet hole 2163 on the longitudinal groove 2161. When the pressure in the smoke collecting pipe 216 reaches the opening pressure of the explosion-proof valve 213, the explosion-proof valve 213 opens to release the high-temperature smoke and particles.

[0056] The area of ​​the flue gas collecting duct 216 in contact with the upper surface of the battery module 100 is only a small proportion compared to the upper surface area of ​​the entire battery module 100. The flue gas collecting duct 216 confines the high-temperature flue gas and particles in the duct, avoiding large-area contact between the battery module 100 and the high-temperature flue gas, and reducing the impact of the high-temperature flue gas and particles on the battery module 100. In addition, the volume of the flue gas collecting duct 216 is only a small part compared to the volume of the gap between the battery module 100 and the box cover 212, which is equivalent to only a small part of the gap above the battery module 100 being filled with high-temperature flue gas, which contains less heat, and can effectively reduce the temperature above the battery module 100 when the battery cell 20 is in thermal runaway, thereby improving the safety of the power battery pack.

[0057] Figure 5 FIG. 2 shows another structure of the smoke collecting pipe 216 in this embodiment. Figure 5 As shown, the smoke collecting duct 216 is composed of a square tube, which includes a plurality of longitudinal square tubes 61 arranged in parallel and a transverse square tube 62 arranged perpendicular to the longitudinal square tubes 61. The transverse square tube 62 connects the longitudinal square tubes 61 in sequence in the middle of the longitudinal square tubes 61. In order to strengthen the strength of the smoke collecting duct 216, the ends of the longitudinal square tubes 61 are connected and fixed by side beams 63. A plurality of smoke inlet holes 2163 are provided at the bottom of each longitudinal square tube 61, and the smoke inlet holes 2163 correspond to the battery cell smoke exhaust holes 1211 on the shell cover 12.

[0058] The smoke collecting pipe 216 mainly composed of square tubes is installed above the battery module 100, and the bottom surface of the longitudinal square tube 61 can be coated with glue so that the longitudinal square tube 61 is bonded and fixed to the shell cover 12 of the battery module 100. One longitudinal square tube 61 corresponds to a row of battery cell smoke exhaust holes 1211 on the shell cover 12 of the battery module 100, and the longitudinal square tube 61 covers a row of battery cell smoke exhaust holes 1211. The smoke inlet hole 2163 at the bottom of the longitudinal square tube 61 is connected to the battery cell smoke exhaust holes 1211 in a one-to-one correspondence. In this embodiment, the explosion-proof valve 213 can be installed on the smoke collecting pipe 216 and communicated with the internal space of the smoke collecting pipe 216. The explosion-proof valve hole is set on the box cover 212 for the outlet of the explosion-proof valve 213 to communicate with the outside.

[0059] like Figures 6 to 8As shown, the battery module 100 includes a module shell 10 and a plurality of battery cells 20 arranged in an inner cavity of the module shell 10 .

[0060] The module shell 10 of the battery module 100 includes a shell 11 with an open top and a shell cover 12 for closing the open shell 11. The shell cover 12 is used to prevent accidents caused by dust, tools, or human hands before the battery module 100 is assembled into the power battery pack 200, and to achieve insulation between the battery cell 20, the battery module 100 and the box cover 212.

[0061] like Fig.10 As shown, the shell cover 12 includes a shell cover plate 121 and a shell cover skirt 122 located around the edges of the shell cover plate 121 . The shell cover plate 121 and the shell cover skirt 122 are an integral structure formed by bending. The shell cover skirt 122 is used to connect with the shell body 11 .

[0062] In the housing 11, as Figure 7 Figure 8 As shown, the plurality of battery cells 20 are arranged in rows and columns, and the electrode arrangement surface 21 of the battery cell 20 is arranged toward the shell cover plate 121 of the shell cover 12. The structure of the battery cell 20 is as shown in FIG. Fig. 9 As shown, a positive electrode 22 , a negative electrode 23 and a cell pressure relief valve 24 are arranged on the electrode arrangement surface 21 .

[0063] The shell cover 121 is provided with battery cell smoke exhaust holes 1211 corresponding to the battery cell pressure relief valves 24 one by one. The inner cavity of the module shell 10 is provided with battery cell smoke exhaust ducts 34 corresponding to the battery cell pressure relief valves 24. The two ends of each battery cell smoke exhaust duct 34 are connected to a battery cell smoke exhaust hole 1211 and a battery cell pressure relief valve 24 respectively. The battery cell smoke exhaust duct 34 is provided with a one-way valve 50 that unidirectionally conducts from the battery cell pressure relief valve 24 to the battery cell smoke exhaust hole 1211.

[0064] The battery module 100 is installed in the electrical box 210 of the power battery pack 200. A smoke collecting pipe 216 is arranged in the electrical box 210. The smoke exhaust holes 1211 of each battery cell of the battery module 100 are connected to the smoke collecting pipe 216 at the same time. When a battery cell 20 in the battery module 100 has thermal runaway and sprays high-temperature smoke and particles, due to the presence of the one-way valve 50, the high-temperature smoke and particles entering the smoke collecting pipe 216 can only be discharged from the electrical box 210 through the smoke collecting pipe 216, and cannot enter from the smoke collecting pipe 216 through the battery cell smoke exhaust holes 1211 and the battery cell smoke exhaust duct 34 of the battery module 100 to contact the outside of the battery cell pressure relief valve 24 of other normal battery cells and affect the battery cell 20. Therefore, the safety of the battery module 100 is improved.

[0065] The battery cell 20 is arranged in the shell 11, and there is a certain gap space between the electrode arrangement surface 21 of the battery cell 20 and the shell cover plate 121. This space is usually used to arrange materials and components such as insulation, heat insulation, wiring harness or wire board. In this embodiment, this space is also used to arrange the battery cell exhaust duct 34, one end of the battery cell exhaust duct 34 is connected to the battery cell pressure relief valve 24, and the other end is connected to the battery cell exhaust hole 1211 on the shell cover plate 121, so that the high-temperature smoke and particles ejected by the battery cell 20 during thermal runaway are guided to the outside of the battery module 100, that is, guided to the smoke collection pipe 216.

[0066] The structure of the battery cell smoke exhaust duct 34 can be composed of a pipe, for example, a heat-resistant pipe made of an insulating material, the two ends of which are respectively connected to the battery cell smoke exhaust hole 1211 and the battery cell pressure relief valve 24, and the one-way valve 50 is arranged in the heat-resistant pipe. The one-way valve 50 can be a spherical or sheet-shaped component that cooperates with the heat-resistant pipe to form a one-way conduction and reverse blocking structure.

[0067] The structure of the battery cell exhaust duct 34 can also be in other forms, for example, a heat-resistant insulating pad 30 is arranged in the gap space between the electrode arrangement surface 21 of the battery cell 20 and the shell cover plate 121, such as Figure 7 As shown, the heat-resistant insulating pad 30 is made of an elastic, electrically insulating and heat-resistant material, and its two sides are coated with glue, and the adhesive is bonded to the shell cover plate 121 and the surface of the electrode arrangement surface 21 around the battery cell pressure relief valve 24 to form a seal. A smoke exhaust through hole 31 corresponding to the battery cell pressure relief valve 24 is provided in the heat-resistant insulating pad 30, and the two ends of the smoke exhaust through hole 31 are respectively connected to the battery cell pressure relief valve 24 and the battery cell smoke exhaust hole 1211. Each smoke exhaust through hole 31 in the heat-resistant insulating pad 30 constitutes a battery cell smoke exhaust duct 34 connected to each battery cell pressure relief valve 24.

[0068] Another arrangement structure of the battery cell exhaust duct 34 is as follows Figure 8 Fig.12 As shown, the heat-resistant insulating pad 30 includes a first insulating pad 32 bonded to the battery cell 20 and a second insulating pad 33 bonded to the shell cover 121, and an information acquisition circuit board 40 is sandwiched between the first insulating pad 32 and the second insulating pad 33. The information acquisition circuit board 40 is connected to the electrodes, sensors and other electrical devices of the battery cell 20, and is used to obtain relevant information of the battery cell 20. The two sides of the information acquisition circuit board 40 can be coated with glue and bonded to the first insulating pad 32 and the second insulating pad 33 respectively. The two side surfaces of the first insulating pad 32 are bonded to the electrode arrangement surface 21 of the battery cell 20 and the information acquisition circuit board 40 by adhesive, and the two side surfaces of the second insulating pad 33 are bonded to the shell cover 121 and the information acquisition circuit board 40 by adhesive, forming a three-layer bonded arrangement structure.

[0069] like Figure 8As shown, the battery cell smoke exhaust duct 34 is composed of a first through hole 311, a second through hole 312, and a third through hole 313 connected to each other, wherein the first through hole 311 is arranged in the first insulating pad 32, the second through hole 312 is arranged in the second insulating pad 33, and the third through hole 313 is arranged on the information acquisition circuit board 40. The first through hole 311, the second through hole 312, and the third through hole 313 belonging to the same battery cell smoke exhaust duct 34 are coaxially aligned.

[0070] like Fig.11 Fig.12 As shown, the one-way valve 50 is arranged in the battery cell smoke exhaust hole 1211. The one-way valve 50 includes a valve sheet 51 arranged in the battery cell smoke exhaust hole 1211, the valve sheet 51 can be attached to the heat-resistant insulation pad 30 and cover the end of the battery cell smoke exhaust channel 34, and the valve sheet 51 is connected to the shell cover 121 at its edge through an elastic connection part 52.

[0071] The valve sheet 51 is in the shape of a thin sheet. When the pressure on both sides is equal, the valve sheet 51 adheres to the surface of the heat-resistant insulating pad 30 by relying on the elastic force of the elastic connecting part 52. The shape of the valve sheet 51 is roughly the same as the shape of the end of the battery cell smoke exhaust duct 34, and its size is slightly larger, so that it can cover the end of the closed battery cell smoke exhaust duct 34.

[0072] A pressure balance hole 53 is provided in the middle of the valve plate 51 . When the one-way valve 50 is in a closed state, the pressure balance hole 53 connects the battery cell exhaust duct 34 with the outside, so that the pressure inside the battery cell exhaust duct 34 and the outside are balanced.

[0073] The shape of the battery cell smoke exhaust hole 1211 is similar to the end of the battery cell smoke exhaust channel 34, and its cross section is usually circular or oblong. Fig.11 FIG. 5 shows a valve plate 51 in an oblong shape, and the elastic connection portion 52 is arranged at one of the two arc ends. The elastic connection portion 52 can also be arranged at other positions, such as being arranged at one of the straight edges on both sides of the valve plate 51, or being arranged at the middle of both straight edges, such as Fig.13 shown.

[0074] The valve sheet 51, the elastic connecting part 52 and the shell cover plate 121 can be an integral structure. Most of the material around the valve sheet 51 is removed through a stamping process, leaving only a small part of the material to form the elastic connecting part 52, thereby forming the battery cell smoke exhaust hole 1211 and the valve sheet 51 and the elastic connecting part 52 located in the battery cell smoke exhaust hole 1211.

[0075] The valve plate 51 , the elastic connection part 52 and the shell cover plate 121 may also be independent parts connected by welding. The elastic connection part 52 may be an elastic sheet connected to the valve plate 51 and the shell cover plate 121 by welding.

[0076] Figures 14 to 16Another arrangement of the one-way valve in this embodiment is shown. Fig.14 As shown, a partition 70 is arranged on the upper side of the battery module 100, and the lower side of the partition 70 is coated with adhesive to be bonded to the upper surface of the shell cover 12, and the partition 70 is provided with a valve through hole 71 corresponding to the position above each battery cell smoke exhaust hole 1211; the size of the valve through hole 71 is slightly larger than the battery cell smoke exhaust hole 1211. A one-way valve 50 is arranged in the valve through hole 71, which conducts one-way from the battery cell smoke exhaust hole 1211 to the outside.

[0077] like Fig.15 and Fig.16 As shown, the one-way valve 50 includes a valve plate 51 arranged in the valve through hole 71, the valve plate 51 can be attached to the shell cover plate 121 and cover the closed battery cell smoke exhaust hole 1211, and the valve plate 51 is connected to the partition 70 at its edge through the elastic connection part 52. The valve plate 51 is provided with an air pressure balance hole 53 connecting the two sides of the valve plate 51.

[0078] The valve plate 51, the elastic connecting part 52 and the partition 70 can be an integral structure. Most of the material around the valve plate 51 is removed through a stamping process, leaving only a small part of the material to form the elastic connecting part 52, thereby forming a valve through hole 71 and the valve plate 51 and the elastic connecting part 52 located in the valve through hole 71 on the partition 70.

[0079] The valve plate 51, the elastic connecting part 52 and the partition 70 can also be independent parts connected by welding. The valve through hole 71 is formed on the partition 70 through a stamping process. The elastic connecting part 52 can be an elastic thin sheet, which connects the valve plate 51 and the partition 70 by welding.

[0080] In the battery system 300 of an electric vehicle, a plurality of power battery packs 200 are usually configured, such as Figure 2 As shown, a plurality of power battery packs 200 are stacked.

[0081] This embodiment also provides an electric vehicle, which includes a battery system 300, and the battery system 300 includes at least one of the aforementioned power battery packs 200. The electric vehicle can be an engineering machine, such as a loader, an excavator, etc., or a road vehicle, such as a truck, a bus, etc.

[0082] like Fig.17 As shown, the battery system 300 includes three power battery packs 200, and the three power battery packs 200 are stacked. Figure 2 As shown, the battery system 300 is electrically connected to the motor system 500 through the control system 400 to provide driving power for the motor system 500 .

[0083] In the present embodiment, a one-way valve 50 is provided on the battery cell exhaust duct in the battery module 100. When some battery cells 20 are in thermal runaway, the high-temperature flue gas entering into the flue gas collecting duct 216 can be prevented from contacting other normal battery cells 20 through the battery cell exhaust duct 34, thereby avoiding the spread of thermal runaway that may be caused thereby. At the same time, the flue gas collecting duct 216 reduces the heat transfer area and heat transfer amount of the high-temperature flue gas to each battery module 100, thereby improving the safety of the battery module 100 and the power battery pack 200 including the battery module 100.

Claims

1. A power battery pack, comprising an electric box and a plurality of battery modules; the electric box comprises a box body and a box cover; characterized in that: Each of the battery modules is arranged in the box body, and a battery cell smoke exhaust hole is provided on the shell cover of each of the battery modules. Each of the battery cell smoke exhaust holes is connected with the battery cell pressure relief valve of each battery cell under the shell cover through the battery cell smoke exhaust duct, and the shell cover is arranged upward and opposite to the box cover; each of the battery cell smoke exhaust holes is arranged in multiple rows vertically; a smoke collecting pipe that can exhaust to the outside through an explosion-proof valve is arranged under the box cover, and the smoke collecting pipe includes a longitudinal pipe and a transverse pipe connecting the longitudinal pipes, and one of the longitudinal pipes is arranged above each row of battery cell smoke exhaust holes, and the bottom surface of each of the longitudinal pipes is sealed and fitted with the shell cover of the battery module and covers the battery cell smoke exhaust holes of the corresponding row, and a smoke inlet hole is provided at the bottom of each of the longitudinal pipes, which is correspondingly connected with the battery cell smoke exhaust holes below it.

2. The power battery pack according to claim 1, characterized in that: The smoke collecting pipe is composed of a square tube.

3. The power battery pack according to claim 1, characterized in that: The box cover includes an upper cover plate and a lower cover plate fixedly connected to the upper cover plate at the edges thereof. The lower cover plate is provided with a plurality of longitudinal grooves with square cross-sections and recessed downwards, and transverse grooves interconnecting the longitudinal grooves. The tops of the longitudinal grooves and transverse grooves are sealed, fitted and fixedly connected to the bottom surface of the upper cover plate to form the smoke collecting duct.

4. The power battery pack according to any one of claims 1 to 3, characterized in that: The battery cell smoke exhaust duct is composed of a heat-resistant tube whose two ends are respectively connected to the battery cell pressure relief valve and the battery cell smoke exhaust hole, and a one-way valve is arranged in the heat-resistant tube to conduct one-way from the battery cell pressure relief valve to the battery cell smoke exhaust hole.

5. The power battery pack according to any one of claims 1 to 3, characterized in that: A heat-resistant insulating pad is arranged between the shell cover and the battery cell. The two back sides of the heat-resistant insulating pad are respectively sealed and connected to the shell cover and the battery cell. The heat-resistant insulating pad is provided with a smoke exhaust through hole constituting the smoke exhaust duct of the battery cell.

6. The power battery pack according to claim 5, characterized in that: The heat-resistant insulating pad comprises a first insulating pad bonded to the battery cell and a second insulating pad bonded to the shell cover, and an information collection circuit board is sandwiched between the first insulating pad and the second insulating pad.

7. The power battery pack according to claim 5, characterized in that: A one-way valve that conducts one-way to the outside is arranged in the battery cell smoke exhaust hole. The one-way valve includes a valve sheet arranged in the battery cell smoke exhaust hole. The valve sheet can fit with the heat-resistant insulating pad and cover and close the end of the smoke exhaust hole. The valve sheet is connected to the shell cover at its edge through an elastic connecting part.

8. The power battery pack according to claim 1, characterized in that: A partition whose lower side is bonded to the shell cover is arranged on the upper side of the battery module, and the partition is provided with valve through holes at the position above each of the battery cell smoke exhaust holes; the valve through holes are larger than the battery cell smoke exhaust holes, and a one-way valve is arranged therein for unidirectional conduction from the battery cell smoke exhaust holes to the outside; the one-way valve includes a valve sheet arranged in the valve through hole, the valve sheet can be bonded to the shell cover and cover and close the battery cell smoke exhaust holes, and the valve sheet is connected to the partition at its edge through an elastic connecting portion.

9. The power battery pack according to claim 7 or 8, characterized in that: The valve plate is provided with an air pressure balance hole communicating with both sides of the valve plate.

10. An electric vehicle, comprising a battery system, characterized in that: The battery system includes the power battery pack according to any one of claims 1 to 9.

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