Battery pack and electric vehicle

Abstract

The invention relates to the technical field of battery safety, in particular to a battery pack and an electric vehicle. The battery pack comprises an alarm device, a battery compartment and a battery pack, a VOC sensor, a pressure sensor and a temperature sensor which are all connected with the control module are arranged on the battery bin, an inert immersion liquid capable of immersing the battery pack is arranged in an inner cavity, and a circulating pump capable of enabling the inert immersion liquid to circularly flow is arranged on the battery bin; a flame-retardant coating is arranged on the side, close to the inner cavity, of the battery bin. The electric vehicle comprises the battery pack. The invention provides a battery pack and an electric vehicle to reduce potential safety hazards caused by thermal runaway of the battery pack.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery safety, and in particular to a battery pack and an electric vehicle. BACKGROUND

[0002] The battery pack is an important component of the electric vehicle, and mainly provides driving power for the electric vehicle. In order to pursue higher endurance capability, multiple single batteries are closely arranged in the box body of the battery pack. The high-density arrangement makes the safety and thermal stability of the battery pack poor. Meanwhile, under the influence of overcharge, overdischarge, overheating, mechanical impact and other factors, the battery separator of each single battery in the battery pack is prone to collapse and internal short circuit, thereby causing thermal runaway of the battery pack and causing safety hazards.

[0003] Therefore, the present application provides a new battery pack and an electric vehicle for the above problems. SUMMARY

[0004] The present application aims to provide a battery pack to reduce safety hazards caused by thermal runaway of the battery pack.

[0005] The present application also aims to provide an electric vehicle to further reduce safety hazards caused by thermal runaway of the battery pack.

[0006] Based on the above first purpose, the present application provides a battery pack for an electric vehicle, wherein the electric vehicle comprises a control module, and the battery pack comprises an alarm device, a battery compartment provided with an inner cavity, and a battery pack provided in the inner cavity; The battery compartment is provided with a VOC sensor, a pressure sensor and a temperature sensor. The VOC sensor is used to monitor the electrolyte volatile gas in the inner cavity. The pressure sensor is used to monitor the pressure of the inner cavity. The temperature sensor is used to monitor the temperature of the inner cavity. The alarm device, the VOC sensor, the pressure sensor and the temperature sensor are all connected with the control module; When the VOC sensor detects that the inner cavity has electrolyte volatile gas, a signal is sent to the control module, and the control module controls the alarm device to start; When the pressure sensor detects that the pressure of the inner cavity reaches a preset maximum pressure, and / or when the temperature sensor detects that the temperature of the inner cavity reaches a preset maximum temperature, a signal is sent to the control module, and the control module controls the power supply circuit of the battery pack to be powered off; The inner cavity is provided with an inert immersion liquid capable of immersing the battery pack. The battery compartment is provided with a circulating pump capable of circulating the inert immersion liquid; The battery compartment is provided with a flame-retardant coating on the side close to the inner cavity.

[0007] Further, the alarm device comprises one or more of a display screen, a display lamp and a buzzer.

[0008] Further, the battery compartment comprises a compartment body and a compartment cover arranged on the compartment body, and the inner cavity is formed between the compartment body and the compartment cover. The VOC sensor, the pressure sensor and the temperature sensor are arranged on the compartment cover, and the circulating pump is arranged on the compartment body.

[0009] Further, the compartment cover is provided with a pressure relief valve in communication with the inner cavity.

[0010] Further, the compartment cover is provided with a first support column for supporting the top end of the battery pack, the side wall of the compartment body is provided with a second support column for supporting the side surface of the battery pack, and the bottom plate of the compartment body is provided with a third support column for supporting the bottom surface of the battery pack.

[0011] Further, the side wall and the bottom plate of the compartment body each comprise a stainless steel lining and a carbon fiber shell arranged on the side of the stainless steel lining away from the inner cavity.

[0012] Further, the inert immersion liquid is a fluorinated liquid.

[0013] Further, the flame-retardant coating is a polyphosphamide-based composite material.

[0014] Further, the battery pack further comprises a high-pressure pump arranged in the battery compartment and in communication with the inert immersion liquid, and the high-pressure pump is connected with the control module.

[0015] By adopting the above technical scheme, the battery pack has at least the following beneficial effects: When the battery pack is affected by overcharging, overdischarging, overheating, mechanical impact and other factors, thermal runaway of the battery pack is caused, which generally causes the following problems: the battery pack is damaged, electrolyte leakage is caused, the electrolyte leakage volatilizes to cause the pressure in the inner cavity to rise, and the temperature in the inner cavity rises.

[0016] The inner cavity is provided with an inert immersion liquid, the inert immersion liquid can immerse the battery pack, and the inert immersion liquid is circulated and flowed by the circulating pump, so that the inert immersion liquid can be circulated and flowed to exchange heat with the battery pack, to dissipate heat of the battery pack, prevent heat diffusion caused by thermal runaway of the battery pack, and improve the safety of the battery pack.

[0017] In addition, when the battery pack is in thermal runaway, the VOC sensor first monitors the electrolyte volatile gas (such as EC, DMC) in the inner cavity, at this time, sends a signal to the control module, and the control module controls the alarm device to start to warn the personnel; further, when the pressure sensor monitors that the pressure in the inner cavity reaches the preset maximum pressure, or the temperature sensor monitors that the temperature in the inner cavity reaches the preset maximum temperature, a signal is sent to the control module, and the control module controls the power supply circuit of the battery pack to be powered off, and the circuit is cut off to ensure safety; finally, the battery compartment on the side close to the inner cavity is provided with a fire-retardant coating to form a physical isolation layer, which effectively avoids the occurrence of burning and explosion accidents.

[0018] In summary, the battery pack of the embodiment has four levels of thermal runaway protection: the battery pack is immersed in the inert immersion liquid to form the first level of protection, the VOC sensor monitors the electrolyte volatile gas in the inner cavity, which can trigger the alarm device 10-15 minutes earlier than temperature anomaly to form the second level of protection, the pressure and / or temperature in the inner cavity are monitored in real time to cut off the circuit in time to form the third level of protection, and the fire-retardant coating on the battery compartment forms the fourth level of protection, so that the four levels of thermal runaway protection achieve the maximum effect of fire prevention and retardation, and reduce the safety hazards caused by thermal runaway of the battery pack.

[0019] Based on the above second purpose, the application provides an electric vehicle, which comprises a vehicle body and the above battery pack.

[0020] By adopting the above technical scheme, the electric vehicle of the application has at least the following beneficial effects: By arranging the above battery pack in the electric vehicle, the electric vehicle has all the advantages of the above battery pack, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0022] Figure 1 The structural schematic diagram of the electric vehicle provided by the embodiment of the application is shown in the figure; Figure 2 The structural schematic diagram of the battery pack provided by the embodiment of the application is shown in the figure; Figure 3 The structural exploded view of the battery pack provided by the embodiment of the application is shown in the figure; Figure 4 The partial structural schematic diagram of the battery compartment of the battery pack provided by the embodiment of the application is shown in the figure.

[0023] Reference signs: 1-battery pack; 11-battery compartment; 111-compartment body; 112-compartment cover; 113-internal cavity; 12-battery group; 2-VOC sensor; 3-pressure sensor; 4-temperature sensor; 51-first support column; 52-second support column; 53-third support column; 6-circulating pump; 7-high pressure pump; 8-flame-retardant coating; 9-pressure relief valve. DETAILED DESCRIPTION

[0024] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0025] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Example one Please see Figure 1The embodiment provides a battery pack 1 used for an electric vehicle, and the electric vehicle comprises a control module. The battery pack 1 comprises an alarm device (not shown in the figure), a battery compartment 11 provided with an inner cavity 113, and a battery pack 12 arranged in the inner cavity 113; the battery compartment 11 is provided with a VOC sensor 2, a pressure sensor 3 and a temperature sensor 4, the VOC sensor 2 is used for monitoring electrolyte volatile gas in the inner cavity 113, the pressure sensor 3 is used for monitoring the pressure of the inner cavity 113, the temperature sensor 4 is used for monitoring the temperature of the inner cavity 113, and the alarm device, the VOC sensor 2, the pressure sensor 3 and the temperature sensor 4 are connected with the control module.

[0028] When the VOC sensor 2 detects that the inner cavity 113 has electrolyte volatile gas, a signal is sent to the control module, and the control module controls the alarm device to start.

[0029] When the pressure sensor 3 detects that the pressure of the inner cavity 113 reaches a preset maximum pressure, a signal is sent to the control module, and the control module controls the power supply circuit of the battery pack 12 to be powered off; or when the temperature sensor 4 detects that the temperature of the inner cavity 113 reaches a preset maximum temperature, a signal is sent to the control module, and the control module controls the power supply circuit of the battery pack 12 to be powered off; or when the pressure sensor 3 detects that the pressure of the inner cavity 113 reaches a preset maximum pressure and the temperature sensor 4 detects that the temperature of the inner cavity 113 reaches a preset maximum temperature, a signal is sent to the control module, and the control module controls the power supply circuit of the battery pack 12 to be powered off.

[0030] In addition, the inner cavity 113 is provided with inert immersion liquid capable of immersing the battery pack 12, and the battery compartment 11 is provided with a circulating pump 6 capable of circulating the inert immersion liquid; and the battery compartment 11 is provided with a fire-retardant coating 8 close to the inner cavity 113.

[0031] It should be noted that the battery pack 1 of the embodiment is used for an electric vehicle, and provides driving power for the electric vehicle. The electric vehicle can be an electric two-wheeled vehicle, an electric three-wheeled vehicle or an electric motorcycle, etc. In addition, the inert immersion liquid is, for example, fluorinated liquid, and the VOC sensor 2 (Volatile Organic Compounds, referred to as VOC) is a sensor used for detecting volatile organic compounds, and can sense the starting volatilization concentration of electrolyte in the fluorinated liquid.

[0032] When the battery pack 1 is affected by factors such as overcharge, overdischarge, overheating and mechanical impact, thermal runaway of the battery pack 1 is caused, which generally causes the following problems: the battery pack 12 is damaged, electrolyte leakage is caused, electrolyte leakage volatilization causes the pressure of the inner cavity 113 to rise, and the temperature of the inner cavity 113 rises.

[0033] The inner cavity 113 is provided with inert immersion liquid, the inert immersion liquid can immerse the battery pack 12, and the inert immersion liquid is circulated and flowed by the circulating pump 6, so that the inert immersion liquid can be circulated and exchanged heat with the battery pack 12 to dissipate heat of the battery pack 12, prevent heat diffusion caused by thermal runaway of the battery pack 12, and improve safety of the battery pack 1.

[0034] In addition, when the battery pack 1 is in thermal runaway, the VOC sensor 2 first detects that the inner cavity 113 has electrolyte volatile gas (such as EC, DMC), at this time, a signal is sent to the control module, the control module controls the alarm device to start to alarm the personnel; further, when the pressure sensor 3 detects that the pressure of the inner cavity 113 reaches the preset maximum pressure, or the temperature sensor 4 detects that the temperature of the inner cavity 113 reaches the preset maximum temperature, a signal is sent to the control module, the control module controls the power supply circuit of the battery pack 12 to be powered off, and the circuit is cut off to ensure safety; finally, the battery compartment 11 on the side close to the inner cavity 113 is provided with a fire-retardant coating 8 to form a physical isolation layer, which effectively avoids the occurrence of combustion and explosion accidents.

[0035] In summary, the battery pack 1 of the embodiment has four levels of thermal runaway protection: the inert immersion liquid immerses the battery pack 12 to form the first level of protection, the VOC sensor 2 monitors the electrolyte volatile gas in the inner cavity 113, which can trigger the alarm device 10 minutes-15 minutes earlier than temperature anomaly to form the second level of protection, the pressure and / or temperature of the inner cavity 113 are monitored in real time to cut off the circuit in time to form the third level of protection, and the fire-retardant coating 8 on the battery compartment 11 forms the fourth level of protection, so that the four levels of thermal runaway protection can maximize the fire-retardant effect and reduce the safety hazards caused by thermal runaway of the battery pack 1.

[0036] Preferably, in the embodiment, the alarm device includes one or more of a display screen, a display lamp and a buzzer.

[0037] For example, the alarm device includes a display screen, or the alarm device includes a display lamp, or the alarm device includes a buzzer, or the alarm device includes a display screen, a display lamp and a buzzer to simultaneously remind the personnel by light and sound to play an alarm role.

[0038] Preferably, referring to Figure 2 In the embodiment, the battery compartment 11 includes a compartment body 111 and a compartment cover 112 arranged on the compartment body 111, and the inner cavity 113 is formed between the compartment body 111 and the compartment cover 112; wherein the VOC sensor 2, the pressure sensor 3 and the temperature sensor 4 are arranged on the compartment cover 112, and the circulating pump 6 is arranged on the compartment body 111.

[0039] Preferably, referring to Figure 3In the embodiment, the pressure relief valve 9 is arranged on the cover 112 and communicates with the inner cavity 113. When the electrolyte leaks and volatilizes, the pressure in the inner cavity 113 rises, and the pressure relief valve 9 is automatically opened to release pressure, preventing excessive pressure from causing safety hazards.

[0040] Preferably, referring to Figure 3 and Figure 4 In the embodiment, the first support column 51 is arranged on the cover 112 to support the top end of the battery pack 12, the second support column 52 is arranged on the side wall of the bin body 111 to support the side of the battery pack 12, and the third support column 53 is arranged on the bottom plate of the bin body 111 to support the bottom of the battery pack 12.

[0041] With the above arrangement, after the battery pack 12 is placed in the inner cavity 113, the first support column 51 supports the top end of the battery pack 12, the second support column 52 supports the side of the battery pack 12, and the third support column 53 supports the bottom of the battery pack 12, thereby improving the fixation of the battery pack 12 in the inner cavity 113 and preventing relative movement of the battery pack 12.

[0042] Preferably, in the embodiment, the side wall and the bottom plate of the bin body 111 each include a stainless steel lining and a carbon fiber shell arranged on the side of the stainless steel lining away from the inner cavity 113.

[0043] Preferably, in the embodiment, the inert immersion liquid is a fluorinated liquid. The fluorinated liquid has a dynamic viscosity of <0.8 cSt (25℃), ODP=0, GWP<500, a boiling point of 38-55℃, an insulation strength of >35 kV, and is filled in the battery bin 11 to wrap the battery pack 12.

[0044] Preferably, the liquid level of the fluorinated liquid is 20mm higher than the top of the battery pack 12.

[0045] With the above arrangement, the circulating pump 6 maintains the circulating state of the fluorinated liquid during normal operation of the battery pack 12, thereby playing a role in daily cooling. When the inner cavity 113 is detected to have a thermal runaway feature, the high-pressure pump 7 makes the fluorinated liquid flush the surface of the battery pack 12 in a turbulent state, and the latent heat is taken away by using the heat absorption of phase change of the fluorinated liquid.

[0046] Preferably, in the embodiment, the flame-retardant coating 8 is an ammonium polyphosphate-based composite material. Preferably, the cover 112, the side wall of the bin body 111, and the bottom plate of the bin body 111 are each provided with the flame-retardant coating 8. The flame-retardant coating 8 can expand to form a carbonized layer of 200-500μm when it encounters fire.

[0047] Preferably, referring to Figure 3 In the embodiment, the battery pack 1 further includes a high-pressure pump 7 arranged in the battery bin 11 and communicating with the inert immersion liquid, and the high-pressure pump 7 is connected with the control module.

[0048] When the pressure sensor 3 detects that the pressure of the inner cavity 113 reaches the preset maximum pressure, and / or the temperature sensor 4 detects that the temperature of the inner cavity 113 reaches the preset maximum temperature, a signal is sent to the control module, and the control module controls the high-pressure pump 7 to start, so that the inert immersion liquid in the inner cavity 113 flows at a high speed, further improving the heat dissipation efficiency of the battery pack 12 and ensuring the safety of the battery pack 1.

[0049] Embodiment two Embodiment two provides an electric vehicle, which comprises the battery pack 1 of embodiment one, and the technical features of the battery pack 1 disclosed in embodiment one are also applicable to this embodiment. The technical features of the battery pack 1 disclosed in embodiment one are not described again. The embodiments of the electric vehicle are further described in detail below with reference to the accompanying drawings.

[0050] Please refer to Figure 1 The electric vehicle provided in this embodiment comprises a vehicle body and the above-mentioned battery pack 1. The electric vehicle may be, for example, an electric two-wheeled vehicle, an electric three-wheeled vehicle, or an electric motorcycle.

[0051] When the battery pack 1 of the electric vehicle is affected by overcharging, over-discharging, overheating, mechanical impact, or the like, thermal runaway of the battery pack 1 may occur, which may cause the following problems: the battery pack 12 may be damaged, causing electrolyte leakage; the electrolyte leakage may volatilize, causing the pressure of the inner cavity 113 to rise; and the temperature of the inner cavity 113 may rise.

[0052] The inner cavity 113 is provided with inert immersion liquid, which can immerse the battery pack 12. The inert immersion liquid is circulated by the circulation pump 6, so that the inert immersion liquid can circulate and exchange heat with the battery pack 12 to dissipate heat of the battery pack 12, prevent heat diffusion caused by thermal runaway of the battery pack 12, and improve the safety of the battery pack 1.

[0053] In addition, when the battery pack 1 is in thermal runaway, the VOC sensor 2 first detects that the inner cavity 113 has electrolyte volatilization gas (such as EC and DMC), and sends a signal to the control module. The control module controls the alarm device to start, so as to alert the personnel. Further, when the pressure sensor 3 detects that the pressure of the inner cavity 113 reaches the preset maximum pressure, or the temperature sensor 4 detects that the temperature of the inner cavity 113 reaches the preset maximum temperature, a signal is sent to the control module, and the control module controls the power supply circuit of the battery pack 12 to be powered off, so as to cut off the circuit and ensure safety. Finally, the battery compartment 11 on the side close to the inner cavity 113 is provided with a fire-retardant coating 8 to form a physical isolation layer, which effectively avoids the occurrence of combustion and explosion accidents.

[0054] In summary, in the electric vehicle of the embodiment, the battery pack 1 has four levels of thermal runaway protection: the battery pack 12 immersed in the inert immersion liquid forms the first level of protection, the VOC sensor 2 monitors the electrolyte volatile gas in the inner cavity 113, which can trigger the alarm device 10-15 minutes earlier than the temperature anomaly, forming the second level of protection, real-time monitoring of the pressure and / or temperature of the inner cavity 113 and timely cutting off the circuit forms the third level of protection, and the fire-retardant coating 8 on the battery compartment 11 forms the fourth level of protection, which achieves the maximum effect of fire prevention and retardation through the four levels of thermal runaway protection, reducing the safety hazards caused by thermal runaway of the battery pack 1.

[0055] The electric vehicle of the embodiment has the advantages of the battery pack 1 of the first embodiment, which have been described in detail in the first embodiment and will not be repeated here.

[0056] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery pack for an electric vehicle, the electric vehicle comprising a control module, characterized in that, The battery pack comprises an alarm device, a battery compartment (11) provided with an inner cavity (113), and a battery pack (12) arranged in the inner cavity (113); The battery compartment (11) is provided with a VOC sensor (2), a pressure sensor (3), and a temperature sensor (4), the VOC sensor (2) is used for monitoring the electrolyte volatile gas in the inner cavity (113), the pressure sensor (3) is used for monitoring the pressure of the inner cavity (113), the temperature sensor (4) is used for monitoring the temperature of the inner cavity (113), and the alarm device, the VOC sensor (2), the pressure sensor (3), and the temperature sensor (4) are connected with the control module; When the VOC sensor (2) detects that the inner cavity (113) has electrolyte volatile gas, a signal is sent to the control module, and the control module controls the alarm device to start; When the pressure sensor (3) detects that the pressure of the inner cavity (113) reaches a preset maximum pressure, and / or when the temperature sensor (4) detects that the temperature of the inner cavity (113) reaches a preset maximum temperature, a signal is sent to the control module, and the control module controls the power supply circuit of the battery pack (12) to be powered off; The inner cavity (113) is provided with an inert immersion liquid capable of immersing the battery pack (12), and the battery compartment (11) is provided with a circulating pump (6) capable of circulating the inert immersion liquid; The battery compartment (11) is provided with a fire-retardant coating (8) on the side close to the inner cavity (113).

2. The battery pack of claim 1, wherein, The alarm device comprises one or more of a display screen, a display lamp, and a buzzer.

3. The battery pack of claim 1, wherein, The battery compartment (11) comprises a compartment body (111) and a compartment cover (112) arranged on the compartment body (111), and the inner cavity (113) is formed between the compartment body (111) and the compartment cover (112); The VOC sensor (2), the pressure sensor (3), and the temperature sensor (4) are arranged on the compartment cover (112), and the circulating pump is arranged on the compartment body (111).

4. The battery pack of claim 3, wherein, The compartment cover (112) is provided with a pressure relief valve (9) communicating with the inner cavity (113).

5. The battery pack of claim 3, wherein, The compartment cover (112) is provided with a first support column (51) for supporting the top end of the battery pack (12), the side wall of the compartment body (111) is provided with a second support column (52) for supporting the side of the battery pack (12), and the bottom plate of the compartment body (111) is provided with a third support column (53) for supporting the bottom of the battery pack (12).

6. The battery pack of claim 3, wherein, The side wall and the bottom plate of the compartment body (111) each comprise a stainless steel lining and a carbon fiber shell arranged on the side of the stainless steel lining away from the inner cavity (113).

7. The battery pack of claim 1, wherein, The inert immersion liquid is fluorinated liquid.

8. The battery pack of claim 1, wherein, The fire-retardant coating (8) is a polyphosphoric acid ammonium-based composite material.

9. The battery pack of any one of claims 1-8, wherein, The battery pack further comprises a high-pressure pump (7) arranged in the battery compartment (11) and communicating with the inert immersion liquid, and the high-pressure pump (7) is connected with the control module.

10. An electric vehicle, characterized by comprising: The battery pack (1) according to any one of claims 1 to 9, wherein the vehicle body comprises the battery pack (1).

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