Battery pack with built-in detection device and energy storage device

Abstract

The utility model discloses a battery pack with a built-in detection device and an energy storage device. The battery pack comprises a shell, a plurality of battery cells, a pressure release valve and a thermal runaway detection device. A medium flowing channel is formed between the battery cell and the top wall of the shell, a detection area is formed between the medium flowing channel and a pressure release valve arranged on the side wall of the shell, and the thermal runaway detection device is located in the detection area and used for detecting eruption of a thermal runaway medium when thermal runaway happens to the battery cell. The thermal runaway detection device detects the thermal runaway medium at any time in the working process of the battery pack, so that early detection of abnormal battery cells in the battery pack is realized, and the safety performance of the battery pack is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery pack and energy storage device with a built-in detection device. Background Art

[0002] Lithium-ion batteries, with their high energy density, low self-discharge rate, long cycle life and environmental friendliness, have been used in electric vehicles and energy storage power stations. Lithium batteries usually work in complex environments. Due to the presence of active electrode materials and flammable electrolytes inside them, they are inevitably subject to overcharge, over-discharge, overheating, external stress, mechanical extrusion and other abuses, as well as electrical abnormalities, which can easily cause temperature rise. Because of people's pursuit of high energy density, single cells are often connected in series and parallel to form modules, battery packs and battery clusters. This spatial limitation creates a more severe heat dissipation environment, and it is easier for heat to accumulate inside the battery, thus triggering thermal runaway.

[0003] If the thermal runaway of lithium-ion batteries cannot be suppressed in the early stage of thermal runaway of battery packs, it will spread between modules and battery clusters, thus causing larger-scale fire and explosion accidents. In recent years, lithium-ion battery fire and explosion accidents have been frequently reported, which not only restricts the further development of lithium-ion batteries, but also poses a great threat to people's lives and property safety.

[0004] Therefore, it is of great significance to develop a thermal runaway early warning solution for battery packs to prevent the spread of thermal runaway and cause fire and explosion. Utility Model Content

[0005] The embodiments of the present application provide a battery pack and an energy storage device with a built-in detection device. A thermal runaway detection device is arranged inside the battery pack. The thermal runaway detection device has the advantage of detecting the concentration of the thermal runaway medium at any time during the operation of the battery pack, thereby realizing early detection of abnormal battery cells in the battery pack and improving the safety performance of the battery pack.

[0006] In a first aspect, an embodiment of the present application provides a battery pack with a built-in detection device, the battery pack comprising a shell, a plurality of battery cells, a pressure relief valve and a thermal runaway detection device, the plurality of battery cells and the thermal runaway detection device being arranged inside the shell, the shell comprising a top wall, a bottom wall and a side wall connected between the top wall and the bottom wall, the pressure relief valve being arranged on the side wall; the plurality of battery cells each comprising an explosion relief valve, the explosion relief valve being used to spray a thermal runaway medium when thermal runaway occurs in the battery cell, all of the explosion relief valves facing the top wall, a medium flow channel being formed between the plurality of battery cells and the top wall, a detection area being formed between the medium flow channel and the pressure relief valve, the medium flow channel being used to transport the thermal runaway medium to the detection area; the thermal runaway detection device is located in the detection area and is used to detect the thermal runaway medium.

[0007] In the embodiment of the present application, a thermal runaway detection device is arranged in a detection area formed between the medium flow channel and the pressure relief valve. When a battery cell experiences thermal runaway, the explosion relief valve of the battery cell sprays the thermal runaway medium, and the thermal runaway medium flows along the medium flow channel to the detection area. Before the pressure relief valve is opened, the thermal runaway detection device detects the thermal runaway medium in the detection area and can initiate a thermal runaway warning.

[0008] The battery pack provided in the embodiment of the present application can detect the thermal runaway phenomenon of the battery pack before the pressure relief valve is opened through the thermal runaway detection device, and warn of the failure of the battery cell, which can prevent the thermal runaway of a certain battery cell in the battery pack from spreading. Moreover, the thermal runaway detection device inside the battery pack can detect the thermal runaway medium at any time during the operation of the battery pack, and can detect the failure in time, which is beneficial to improving the safety performance of the battery pack. If the battery pack is used in an energy storage device, the battery pack can also ensure the safety performance of the energy storage device, and can issue a warning before the pressure relief valve of the battery pack is opened, so as to prevent the opening of the pressure relief valve from causing a safety failure of the energy storage system, which is beneficial to reduce the loss of personal safety and property.

[0009] In a possible implementation, the battery pack includes a length direction and a height direction, the top wall and the bottom wall are arranged relatively along the height direction, the multiple battery cells are arranged in at least one row, the arrangement direction of each row of battery cells is the length direction, and the detection area is formed between each row of battery cells and the side wall where the pressure relief valve is located; the thermal runaway detection device is arranged between the battery cell and the pressure relief valve in the length direction, and the thermal runaway detection device is arranged between the medium flow channel and the pressure relief valve in the height direction. This solution can achieve that the thermal runaway medium contacts the thermal runaway detection device before contacting the pressure relief valve through the arrangement scheme that the thermal runaway detection device is arranged between the medium flow channel and the pressure relief valve in the height direction, which is conducive to thermal runaway detection and early warning before the pressure relief valve is opened.

[0010] In a possible implementation, the number of the medium flow channels and the number of rows of the multiple battery cells are set correspondingly, and an independent medium flow channel is formed between each row of the battery cells and the top wall. Through the independence of the medium flow channels, this solution can ensure that the thermal runaway medium of each row of battery cells has an independent channel to reach the detection area, avoiding the mixing of thermal runaway media of different rows of battery cells, and is also helpful in detecting which specific row of battery cells has failed. The row of battery cells with a fault can be controlled to stop working, and other battery cells without faults continue to work normally, thereby maintaining the working state of the battery pack.

[0011] In one possible implementation, the number of the medium flow channels is at least two, each of the medium flow channels extends along the length direction, the end of the medium flow channel is connected to the detection area and faces the side wall where the pressure relief valve is located, and the pressure relief valve is arranged between at least two of the medium flow channels in the width direction.

[0012] In a possible implementation, the number of the thermal runaway detection devices is two or more, and they are arranged at intervals along the width direction. This solution can improve the accuracy of thermal runaway detection and improve the safety of the battery pack by arranging at least two thermal runaway detection devices at intervals.

[0013] In a possible implementation, the pressure relief valve is located at the center of the side wall in the width direction, and the number of the thermal runaway detection devices is an even number, and they are symmetrically distributed on both sides of the pressure relief valve in the width direction. The even number of symmetrically distributed thermal runaway detection devices provided in this solution is conducive to providing accuracy in thermal runaway detection and improving the safety of the battery pack.

[0014] In one possible implementation, the number of the thermal runaway detection device is one, and along the length direction, the thermal runaway detection device is located between the pressure relief valve and the battery cell, and the vertical projection of the thermal runaway detection device on the side wall where the pressure relief valve is located is located directly above the pressure relief valve, or the vertical projection of the thermal runaway detection device on the side wall where the pressure relief valve is located partially overlaps with the pressure relief valve.

[0015] In a possible implementation, the number of the medium flow channel is one, the multiple battery cells are arranged in a row, and the thermal runaway detection device is arranged between the row of battery cells and the pressure relief valve along the length direction. The battery pack provided by this solution is used in indoor application scenarios.

[0016] In a possible implementation, the battery pack further includes a battery management module, the plurality of battery cells are arranged between the battery management module and the pressure relief valve in the length direction, and the thermal runaway detection device is electrically connected to the battery management module.

[0017] In a possible implementation, the thermal runaway detection device includes at least two detection modules, and the at least two detection modules are respectively used to detect different components in the thermal runaway medium. This solution can improve the efficiency and accuracy of thermal runaway detection and improve the safety of the battery by setting at least two detection modules in the thermal runaway detection device, and at least two detection modules are respectively used to detect different components of the thermal runaway medium.

[0018] In a possible implementation, the battery pack further includes a cold plate, the cold plate and the shell are independent structures, and the cold plate is fixed on the outer side of the bottom wall.

[0019] In a possible implementation, the battery pack further includes a cold plate, the bottom wall is a partial shell of the cold plate, the top wall and the side walls constitute a cover, and the cover and the cold plate are combined to enclose a receiving space.

[0020] The battery pack is a lithium-ion battery pack in an industrial and commercial energy storage system, or a lithium-ion battery pack in a power station energy storage system, or a lithium-ion battery pack in a data center energy storage and backup power system, or a lithium-ion battery pack in a communication base station energy storage and backup power system, or a power lithium-ion battery pack in a new energy vehicle.

[0021] In a second aspect, an embodiment of the present application provides an energy storage device, which includes a plurality of battery packs, and the battery pack is a battery pack of a built-in detection device provided by any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A It is a schematic diagram of the framework structure of the energy storage device provided in the embodiment of the present application;

[0023] Figure 1B It is another schematic diagram of the framework structure of the energy storage device provided in the embodiment of the present application;

[0024] Figure 1C It is another schematic diagram of the framework structure of the energy storage device provided in the embodiment of the present application;

[0025] Figure 2 is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0026] Figure 3A A schematic plan view of a battery pack provided in one embodiment of the present application;

[0027] Figure 3B A schematic plan view of a battery pack provided in one embodiment of the present application;

[0028] Figure 3C A schematic plan view of a battery pack provided in one embodiment of the present application;

[0029] Figure 3D A schematic plan view of a battery pack provided in one embodiment of the present application;

[0030] Figure 4 A three-dimensional schematic diagram of a battery pack in one direction provided by an embodiment of the present application;

[0031] Figure 5 A three-dimensional schematic diagram of a battery pack provided in another direction according to an embodiment of the present application;

[0032] Figure 6 A three-dimensional exploded schematic diagram of a battery pack provided in one embodiment of the present application;

[0033] Figure 7 A schematic diagram of assembling a plurality of battery cells, a battery management module and a thermal runaway detection device in a battery pack provided in one embodiment of the present application;

[0034] Figure 8 A schematic diagram of one side of the connection between the separator and the battery cell in a battery pack provided in one embodiment of the present application;

[0035] Fig. 9 for Figure 8 An enlarged schematic diagram of part I;

[0036] Fig.10 for Figure 8 Schematic diagram of the middle partition;

[0037] Fig.11 A cross-sectional view of a battery pack provided in one embodiment of the present application;

[0038] Fig.12 for Fig.11 An enlarged schematic diagram of part II;

[0039] Fig.13 A schematic plan view of a battery cell and a separator in one direction in a battery pack provided in one embodiment of the present application;

[0040] Fig.14 A schematic diagram of a thermal runaway detection device in a battery pack provided in one embodiment of the present application. DETAILED DESCRIPTION

[0041] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0042] The embodiment of the present application provides a battery pack having a thermal runaway detection device therein. When thermal runaway occurs in one or some of the battery cells 30 in the battery pack, the temperature of the battery cell 30 rises and electrolyte gas is released. The thermal runaway detection device detects electrolyte gas leaking or volatilizing from the battery pack inside the shell of the battery pack, and issues an early warning for thermal runaway failure of the battery pack, thereby achieving early detection of abnormal battery cells in the battery pack, avoiding the spread of thermal runaway, and improving the safety performance of the battery pack.

[0043] The battery pack provided in the present application is used in electronic devices, and the battery pack is used to store energy for the electronic devices or to supply power to functional devices in the electronic devices. In one embodiment, the electronic device can be, but is not limited to, a photovoltaic energy storage device, a vehicle-mounted energy storage device, etc.

[0044] For example, Figure 1A A schematic diagram of the framework structure of an energy storage device 120 is shown. Figure 1A As shown, in one embodiment, the energy storage device 120 is connected between the external power source 110 and the power grid 130 / external load 140 (the power grid 130 / external load 140 refers to the power grid 130 or the external load 140, the same below). The energy storage device 120 may include a power converter 121, a battery pack 122 and a power converter 123.

[0045] The power converter 121 can integrate an AC / DC conversion circuit and a DC / DC conversion circuit, wherein the AC / DC conversion circuit is used to connect to both the external AC power supply and the battery pack 122, and the DC / DC conversion circuit is used to realize the conversion of high and low voltage DC. When the external power supply 110 is a DC source (the DC source includes but is not limited to a photovoltaic array), the DC / DC conversion circuit in the power converter 121 can connect the external power supply 110 to the battery pack 122, so that the external DC power supply can charge the battery pack 122. When the external power supply 110 is an AC source, the AC / DC conversion circuit in the power converter 121 can connect the external power supply 110 to the battery pack 122, so that the external AC power supply can be used to charge the battery pack 122.

[0046] The power converter 123 may integrate a DC / DC conversion circuit and a DC / AC conversion circuit. The DC / DC conversion circuit is used to realize the conversion of high and low voltage direct current, and the DC / AC conversion circuit is used to convert the direct current transmitted by the battery pack 122 into alternating current. The DC / DC conversion circuit in the power converter 123 is used to connect to both the battery pack 122 and the power grid 130 / external load 140, and transmit direct current to the power grid 130 / external load 140. The DC / AC conversion circuit in the power converter 123 is used to connect to both the battery pack 122 and the power grid 130 / external load 140, and transmit alternating current to the power grid 130 / external load 140.

[0047] Illustratively, in this embodiment, the energy storage device 120 may include a power converter 121, a battery pack 122, and a power converter 123. In other embodiments, Figure 1B As shown, the energy storage device 120 may also include only a power converter 121 and a battery pack 122, wherein the power converter 121 is used to connect the external power source 110 and the battery pack 122, so that the external power source 110 can charge the battery pack 122. In other embodiments, Figure 1CAs shown, the energy storage device 120 may also only include a power converter 123 and a battery pack 122 , wherein the power converter 123 is used to connect the battery pack 122 with the power grid 130 / external load 140 , so that the battery pack 122 can transmit electrical energy to the power grid 130 / external load 140 .

[0048] Figure 2 A structural schematic diagram of a vehicle is illustrated, wherein vehicle 200 refers to a wheeled vehicle driven or towed by a power device, wherein vehicle 200 may include but is not limited to electric vehicles / electric vehicles, pure electric vehicles, extended-range electric vehicles, plug-in hybrid vehicles, new energy vehicles, passenger cars, various special operation vehicles with specific functions (such as engineering rescue vehicles, sprinkler trucks, sewage suction trucks, etc.) or robots that can travel, etc.

[0049] like Figure 2 As shown, the vehicle 200 includes a vehicle body 201 and an on-board power supply system 202. The on-board power supply system 202 is installed on the vehicle body 201. The on-board power supply system 202 can supply power to the on-board load 204 through the battery pack 203 to meet the power demand of the normal operation of the on-board load 204. According to the different on-board loads 204, the DC voltage required by each on-board load 204 includes high-voltage DC and low-voltage DC, wherein the high-voltage DC is transmitted to the high-voltage load to supply power to the high-voltage load. For example, the high-voltage load includes a compressor, a seat heating module, a power system, etc., and the low-voltage DC is transmitted to the low-voltage load to supply power to the low-voltage load. For example, the low-voltage load includes an instrument panel, a control display screen, a car light, a USB interface, etc.

[0050] like Figure 2 As shown, in one embodiment, the vehicle power supply system 202 can be charged by an external power source, and the electric energy is stored in the battery pack 203. When it is necessary to power the vehicle load 204, the electric energy stored in the battery pack 203 is released to power the vehicle load 204. Alternatively, the vehicle power supply system 202 may be provided with an on-board charger (OBC) and a DCDC module. The on-board charger is a functional module for charging the battery pack 203 from the AC power grid when the vehicle is parked, and the DCDC module is a functional module for converting high-voltage DC into the DC voltage required for the vehicle load 204 to work. Exemplarily, the DCDC module can power the vehicle load 204.

[0051] Figure 3A A schematic plan view of a battery pack 10 provided in one embodiment of the present application is shown in FIG. Figure 3B A schematic plan view of a battery pack 10 provided in accordance with one embodiment of the present application.

[0052] See also Figure 3A and Figure 3BIn one embodiment, the battery pack 10 includes a shell 20, a plurality of battery cells 30, a pressure relief valve 60 and a thermal runaway detection device 70. The shell 20 includes a top wall 21, a bottom wall 22 and a side wall 23 connected between the top wall 21 and the bottom wall 22. The plurality of battery cells 30 and the thermal runaway detection device 70 are located inside the shell 20. The pressure relief valve 60 is disposed on the side wall 23. Each battery cell 30 includes an explosion relief valve 32, which is used to spray a thermal runaway medium when thermal runaway occurs in the battery cell 30. The thermal runaway medium may include but is not limited to electrolyte gas, hydrogen H2, carbon monoxide CO, smoke, liquid, etc. All of the explosion relief valves 32 of all the battery cells 30 in the battery pack 10 face the top wall 21. The top surface of the battery cell 30 faces the top wall 21, and the explosion relief valve 32 is disposed on the top surface of the battery cell 30. A medium flow channel 80 is formed between the battery cell 30 and the top wall 21. In one embodiment, there is a spacing space between the top surface of the battery cell 30 and the top wall 21, and the battery pack 10 also has a partition 40, which is located between the top wall 21 and the top surface of the battery cell 30, and a medium flow channel 80 is formed between the partition 40 and the top surface of the battery cell 30. A detection area 90 is formed between the medium flow channel 80 and the pressure relief valve 60. The detection area 90 is located between the battery cell 30 adjacent to the side wall 23 and the side wall 23, and this side wall 23 is the side wall 23 where the pressure relief valve 60 is set. The medium flow channel 80 is connected to the detection area 90, and the medium flow channel 80 is used to transport the thermal runaway medium to the detection area 90. The thermal runaway detection device 70 is located in the detection area 90 and is used to detect the thermal runaway medium.

[0053] See also Figure 3A and Figure 3B The battery pack 10 includes a length direction X, a height direction Y and a width direction Z. The top wall 21 and the bottom wall 22 are arranged relatively along the height direction Y. The plurality of battery cells 30 are arranged in at least four rows along the width direction Z. In other embodiments, the plurality of battery cells 30 may also be arranged in one row, two rows, three rows or more rows. The arrangement direction of each row of battery cells 30 is the length direction X. A detection area 90 is formed between each row of battery cells 30 and the side wall 23 where the pressure relief valve 60 is located. The thermal runaway detection device 70 is arranged between the battery cell 30 and the pressure relief valve 60 in the length direction X. The thermal runaway detection device 70 is arranged between the medium flow channel 80 and the pressure relief valve 60 in the height direction Y. In this solution, the thermal runaway detection device 70 is arranged between the medium flow channel 80 and the pressure relief valve 60 in the height direction Y. This solution can achieve that the thermal runaway medium contacts the thermal runaway detection device 70 before contacting the pressure relief valve 60, which is conducive to thermal runaway detection and early warning before the pressure relief valve 60 is opened.

[0054] The number of medium flow channels 80 is set corresponding to the number of rows of multiple battery cells 30, and an independent medium flow channel 80 is formed between each row of battery cells 30 and the top wall 21. Through the independence of the medium flow channels, this solution can ensure that the thermal runaway medium of each row of battery cells has an independent channel to reach the detection area, avoiding the mixing of thermal runaway media of different rows of battery cells, and is also conducive to detecting which row of battery cells has a fault in the detection method. The faulty row of battery cells can be controlled to stop working, and other fault-free battery cells continue to work normally to maintain the working state of the battery pack.

[0055] like Figure 3B As shown, in one embodiment, four rows of battery cells 30 form four independent medium flow channels 80 . The four medium flow channels 80 are in a long strip shape and extend along the length direction X and are all connected to the detection area 90 . Figure 3B The area in the dashed box is the medium flow channel 80 and the detection area 90. Figure 3B The dashed line with an arrow in the middle indicates the direction of flow of the thermal runaway medium.

[0056] See also Figure 3B In one embodiment, the number of thermal runaway detection devices 70 is two. In other embodiments, the number of thermal runaway detection devices 70 may also be three or more. This solution can improve the accuracy of thermal runaway detection and the safety of the battery pack by arranging at least two thermal runaway detection devices at intervals. At least two thermal runaway detection devices 70 are arranged at intervals along the width direction Z. In one embodiment, the pressure relief valve 60 is located at the center of the side wall 23 in the width direction Z, and the number of thermal runaway detection devices 70 is an even number ( Figure 3B In the illustrated embodiment, the number of the thermal runaway detection devices 70 is two, and the thermal runaway detection devices 70 are symmetrically distributed on both sides of the pressure relief valve 60 in the width direction Z.

[0057] Figure 3C A schematic plan view of a battery pack 10 provided in one embodiment of the present application is shown in FIG. Figure 3C In one embodiment, the number of thermal runaway detection devices 70 in the battery pack is one. Along the length direction X of the battery pack, the thermal runaway detection device 70 is located between the pressure relief valve 60 and the battery cell 30, and the vertical projection of the thermal runaway detection device 70 on the side wall 23 where the pressure relief valve 60 is located is located directly above the pressure relief valve 60 (e.g. Figure 3A The vertical projection of the thermal runaway detection device 70 on the side wall 23 where the pressure relief valve 60 is located may partially overlap with the pressure relief valve 60 .

[0058] Figure 3D A schematic plan view of a battery pack 10 provided in one embodiment of the present application is shown in FIG. Figure 3DIn one embodiment, a plurality of battery cells 30 in the battery pack are arranged in a row along the length direction X, and the number of the thermal runaway detection device 70 is one. The thermal runaway detection device 70 is located between the pressure relief valve 60 and the row of battery cells 30. The battery pack 10 provided in this embodiment can be used in indoor use scenarios.

[0059] like Figure 3A As shown, in one embodiment, the battery pack 10 further includes a cold plate 50, the cold plate 50 and the outer shell 20 are independent structures, the cold plate 50 is fixed on the outer side of the bottom wall 22, and the cold plate 50 can be overlapped with the bottom wall 22. In one embodiment, the battery pack 10 further includes a cold plate 50, the bottom wall 22 is a partial shell of the cold plate 50, the top wall 21 and the side wall 23 constitute a cover, and the cover and the cold plate 50 are combined to enclose a receiving space.

[0060] Figure 4 This is a three-dimensional schematic diagram of a battery pack 10 in one direction provided in one embodiment of the present application. Figure 5 This is a three-dimensional schematic diagram of a battery pack 10 provided in another direction according to an embodiment of the present application. Figure 6 A schematic three-dimensional exploded view of a battery pack 10 provided in accordance with one embodiment of the present application.

[0061] See also Figure 4 , Figure 5 and Figure 6 In one embodiment, the bottom wall 22 of the outer shell 20 of the battery pack 10 is a shell of the cold plate 50, and the cold plate 50 is arranged opposite to the top wall 21 and connected to the side wall 23. In the length direction X, a plurality of battery cells 30 are arranged between the battery management module 11 and the pressure relief valve 60. The thermal control detection device and the pressure relief valve 60 are located on the same side of the plurality of battery cells 30, and in the height direction Y, the thermal runaway detection device 70 is located above the side of the pressure relief valve 60. The thermal runaway detection device 70 is electrically connected to the battery management module 11, and the battery management module 11 can receive and process the feedback signal of the thermal runaway detection device 70 to realize early warning of the battery pack 10. In one embodiment, the electrical connection between the thermal runaway detection device 70 and the battery management module 11 can be achieved by connecting a wireless transmission module. This solution avoids setting a transmission line on the periphery of the battery cell 30, so that the circuit layout in the battery pack 10 is simple and compact. In other implementations, the thermal runaway detection device 70 and the battery management module 11 may be electrically connected via a wired line, and the transmission line may be arranged around a fixing frame on the periphery of the battery cell 30 .

[0062] like Figure 5 As described above, the external interfaces of the battery pack 10 are arranged on one side of the battery management module 11, which facilitates the connection between the battery pack 10 and other devices in electronic devices such as energy storage devices and electric vehicles. The external interfaces include circuit interfaces, cold plate water interfaces, etc.

[0063] like Figure 6 As shown, a partition 40 is provided on the top of the battery cell 30, and a medium flow channel 80 is formed between the partition 40 and the explosion relief valve 32 on the top of the battery cell 30. Figure 6 The strip area indicated by the dotted line on the middle partition 40 represents the medium flow channel 80. The edge of the partition 40 facing the pressure relief valve 60 has a notch 49, which constitutes a communication channel between the medium flow channel 80 and the detection area 90. The detection area 90 is the area between the battery cell 30 and the side wall 23 where the pressure relief valve 60 is set, and the thermal runaway detection device 70 is set in the detection area 90.

[0064] Figure 7 A schematic diagram of assembling a plurality of battery cells 30, a battery management module 11 and a thermal runaway detection device 70 in a battery pack 10 according to an embodiment of the present application. Figure 7 , the top surface of each battery cell 30 has an explosion relief valve 32, which is located in the middle area of ​​the top surface of the battery cell 30, and the top side of the battery cell 30 also includes a positive electrode 31 and a negative electrode 33 of the battery cell 30, and the positive electrode 31 and the negative electrode 33 are distributed on both sides of the explosion relief valve 32. The explosion relief valves 32 of each row of battery cells 30 are arranged in a row along the length direction X of the battery pack 10. In the length direction X, the battery management module 11 and the thermal runaway detection device 70 are distributed on opposite sides of the plurality of battery cells 30.

[0065] Figure 8 A schematic diagram of one side of the connection between the separator 40 and the battery cell 30 in the battery pack 10 provided in one embodiment of the present application, Fig. 9 for Figure 8 The enlarged schematic diagram of part I in the figure is as follows: Fig.10 for Figure 8 Schematic diagram of the middle partition plate 40. Figure 8 , Fig. 9 and Fig.10 On one side of the partition 40, a plurality of flat plates 41 are arranged in multiple rows and columns. Along the length direction X, the plurality of flat plates 41 are arranged in a row. The receiving groove 410 formed between two adjacent flat plates 41 is used to receive one battery cell 30. Along the width direction Z, four rows of flat plates 41 are arranged in sequence to form receiving grooves 410 for four rows of battery cells 30. The surface of the partition 40 facing the receiving grooves 410 has grooves 42 extending along the length direction X. Each receiving groove 410 corresponds to a portion of the groove 42, and the grooves 42 corresponding to adjacent receiving grooves 410 are connected. Fig.10As shown, along the length direction X of the battery pack 10, the groove 42 extends in a track shape. In one embodiment, the groove 42 includes three sub-grooves 421, and the three sub-grooves 421 do not extend in the length direction X, and there is a spacer 422 between adjacent sub-grooves 421. The position of the groove 42 is used to face the explosion relief valve 32 on the battery cell 30. When a battery cell 30 has a thermal runaway phenomenon, the thermal runaway medium ejected from the battery cell 30 through the explosion relief valve 32 will enter the groove 42, and flow into the detection area 90 where the thermal runaway detection device 70 is located along the extension direction of the groove 42.

[0066] Fig.11 A cross-sectional view of a battery pack 10 provided in one embodiment of the present application, Fig.12 for Fig.11 An enlarged schematic diagram of part II in FIG. Fig.11 and Fig.12 The groove on the partition 40 faces the battery cell 30, and the groove constitutes at least part of the medium flow channel 80. The medium flow channel 80 runs through all the top areas of the battery cells 30 between the battery cells 30 and the partition 40 along the length direction X of the battery pack 10, and the medium flow channel 80 is connected to the detection area 90.

[0067] Fig.13 This is a schematic plan view of a battery cell 30 and a partition 40 in one direction in a battery pack 10 provided in one embodiment of the present application. Fig.13 , along the width direction Z of the battery pack 10, the two thermal runaway detection devices 70 are distributed on both sides of the pressure relief valve 60. Along the height direction Y of the battery, the two thermal runaway detection devices 70 are located above the pressure relief valve 60. The distance between the thermal runaway detection device 70 and the top wall 21 is smaller than the distance between the pressure relief valve 60 and the top wall 21. In the height direction Y, the distance between the thermal runaway detection device 70 and the medium flow channel 80 is smaller than the distance between the pressure relief valve 60 and the medium flow channel 80. The thermal runaway medium entering the detection area 90 from the medium flow channel 80 is first detected by the thermal runaway detection device 70 before reaching the position of the pressure relief valve 60.

[0068] The battery pack 10 provided in the embodiment of the present application can detect the thermal runaway phenomenon of the battery pack 10 before the pressure relief valve 60 is opened through the thermal runaway detection device 70, and warn of the failure of the battery cell 30, which can prevent the thermal runaway of a certain battery cell 30 in the battery pack 10 from spreading. Moreover, the thermal runaway detection device 70 inside the battery pack 10 can detect the thermal runaway medium at any time during the operation of the battery pack 10, and can discover the failure in time, which is beneficial to improving the safety performance of the battery pack 10. If the battery pack 10 is used in an energy storage device, the battery pack 10 can also ensure the safety performance of the energy storage device, and can warn before the pressure relief valve 60 of the battery pack 10 is opened, so as to prevent the pressure relief valve 60 from opening and causing a safety failure of the energy storage system, which is beneficial to reduce the loss of personal safety and property.

[0069] In one embodiment, the battery pack 10 is provided with four rows of battery cells 30, a pressure relief valve 60 and two thermal runaway detection devices 70. The center of the pressure relief valve 60 is located between the middle two rows of battery cells 30, and the two thermal runaway detection devices 70 are equidistant from the medium flow channel 80.

[0070] In one embodiment, the thermal runaway medium may be electrolyte gas, and the thermal runaway medium may be hydrogen, carbon monoxide gas, smoke, etc. generated after thermal runaway. The thermal runaway detection device 70 is used to detect the concentration of electrolyte gas, and the thermal runaway detection device 70 is used to detect the concentration of hydrogen, the concentration of gases such as carbon monoxide, and the concentration of smoke.

[0071] In one embodiment, the thermal runaway detection device 70 includes at least two detection modules, and the at least two detection modules are respectively used to detect the concentrations of different components in the thermal runaway medium. This solution can improve the efficiency and accuracy of thermal runaway detection and improve the safety of the battery by providing at least two detection modules in the thermal runaway detection device, and at least two detection modules are respectively used to detect the components of different thermal runaway media.

[0072] Fig.14 A schematic diagram of a thermal runaway detection device in a battery pack provided in one embodiment of the present application, see Fig.14The thermal runaway detection device 70 includes a circuit board 75 and a first detection module 71, a second detection module 72 and a third detection module 73 arranged on the circuit board 75, and a control circuit 74 arranged on the circuit board 75. The first detection module 71, the second detection module 72 and the third detection module 73 are all electrically connected to the control circuit 74, and the control circuit 74 is used to collect the signals detected by the first detection module 71, the second detection module 72 and the third detection module 73, and process the information. The first detection module 71, the second detection module 72 and the third detection module 73 can be used to detect different thermal runaway medium components. For example, the first detection module 71 is used to detect the concentration of hydrogen, the second detection module 72 is used to detect the concentration of smoke, and the third detection module 73 is used to detect the concentration of carbon monoxide.

[0073] In one embodiment, the thermal runaway detection device 70 includes a detection module, and the detection module is used to detect the concentration of a certain gas (eg, hydrogen) in the thermal runaway medium.

[0074] In one embodiment, the dimension of the battery pack 10 in the length direction X is 1300 mm, the dimension of the battery pack 10 in the width direction Z is 810 mm, and the dimension of the battery pack 10 in the height direction Y is 250 mm.

[0075] In one embodiment, the battery pack 10 is a lithium-ion battery pack in an industrial or commercial energy storage system.

[0076] In one embodiment, the battery pack 10 is a lithium-ion battery pack in a power station energy storage system.

[0077] In one embodiment, the battery pack 10 is a lithium-ion battery pack in a data center energy storage and backup system.

[0078] In one embodiment, the battery pack 10 is a lithium-ion battery pack in a communication base station energy storage backup system.

[0079] In one embodiment, the battery pack 10 is a power lithium-ion battery pack in a new energy vehicle.

[0080] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery pack with a built-in detection device, characterized in that: It comprises a housing, a plurality of battery cells, a pressure relief valve and a thermal runaway detection device, wherein the plurality of battery cells and the thermal runaway detection device are arranged inside the housing, the housing comprises a top wall, a bottom wall and a side wall connected between the top wall and the bottom wall, and the pressure relief valve is arranged on the side wall; The plurality of battery cells each include an explosion relief valve, the explosion relief valve being used to spray a thermal runaway medium when thermal runaway occurs in the battery cell, all the explosion relief valves facing the top wall, a medium flow channel being formed between the plurality of battery cells and the top wall, a detection area being formed between the medium flow channel and the pressure relief valve, and the medium flow channel being used to transport the thermal runaway medium to the detection area; The thermal runaway detection device is located in the detection area and is used to detect the thermal runaway medium.

2. The battery pack according to claim 1, characterized in that: The battery pack includes a length direction and a height direction, the top wall and the bottom wall are arranged opposite to each other along the height direction, the multiple battery cells are arranged in at least one row, the arrangement direction of the battery cells in each row is the length direction, and the detection area is formed between each row of battery cells and the side wall where the pressure relief valve is located; The thermal runaway detection device is arranged between the battery cell and the pressure relief valve in the length direction, and the thermal runaway detection device is arranged between the medium flow channel and the pressure relief valve in the height direction.

3. The battery pack according to claim 2, characterized in that: The number of the medium flow channels is arranged corresponding to the number of rows of the plurality of battery cells, and an independent medium flow channel is formed between each row of the battery cells and the top wall.

4. The battery pack according to claim 3, characterized in that: The battery pack also includes a width direction, the number of the medium flow channels is at least two, each of the medium flow channels extends along the length direction, the end of the medium flow channel is connected to the detection area and faces the side wall where the pressure relief valve is located, and the pressure relief valve is arranged between at least two of the medium flow channels in the width direction.

5. The battery pack according to claim 4, characterized in that: The number of the thermal runaway detection devices is two or more, and they are arranged at intervals along the width direction.

6. The battery pack according to claim 5, characterized in that: The pressure relief valve is located at the center of the side wall in the width direction, and the number of the thermal runaway detection devices is an even number and is symmetrically distributed on both sides of the pressure relief valve in the width direction.

7. The battery pack according to claim 4, characterized in that: The number of the thermal runaway detection device is one. Along the length direction, the thermal runaway detection device is located between the pressure relief valve and the battery cell. The vertical projection of the thermal runaway detection device on the side wall where the pressure relief valve is located is located directly above the pressure relief valve, or the vertical projection of the thermal runaway detection device on the side wall where the pressure relief valve is located partially overlaps with the pressure relief valve.

8. The battery pack according to claim 7, characterized in that: The number of the medium flow channel is one, the multiple battery cells are arranged in a row, and the thermal runaway detection device is arranged between the row of battery cells and the pressure relief valve along the length direction.

9. The battery pack according to any one of claims 2 to 8, characterized in that: The battery pack further includes a battery management module, the plurality of battery cells are arranged between the battery management module and the pressure relief valve in the length direction, and the thermal runaway detection device is electrically connected to the battery management module.

10. The battery pack according to claim 1, characterized in that: The thermal runaway detection device comprises at least two detection modules, and the at least two detection modules are respectively used to detect different components in the thermal runaway medium.

11. An energy storage device, characterized in that: It comprises a plurality of battery packs, wherein the battery pack is a battery pack as described in any one of claims 1 to 10.

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