Battery pack and vehicle

Abstract

The invention discloses a battery pack and a vehicle, and the battery pack comprises a battery cavity which is used for installing a battery cell; the air pressure detector is mounted outside the battery cavity or on the side wall of the battery cavity, and the air pressure detector is used for detecting the air pressure of the battery pack. According to the battery pack provided by the embodiment of the invention, the air pressure detector is mounted outside the battery cavity or on the side wall of the battery cavity, so that the air pressure detector can be far away from the battery cell and cannot be damaged before a thermal runaway alarm is given when the battery cell is in thermal runaway, thereby improving the success probability of the thermal runaway alarm and improving the safety.

Description

Technical Field

[0001] The present disclosure relates to a battery pack and a vehicle. Background Art

[0002] Related technologies primarily determine whether a battery pack has experienced thermal runaway based on voltage and battery temperature. However, this approach cannot fully meet the requirement of providing a thermal event alarm signal within five minutes of thermal runaway. Furthermore, voltage and battery temperature sensors are typically installed within the battery cell cavity. Summary of the Invention

[0003] The present disclosure aims to provide a battery pack and a vehicle.

[0004] To achieve the above objectives, the present disclosure adopts the following technical solutions:

[0005] The present disclosure provides a battery pack, comprising:

[0006] A battery cavity, wherein the battery cavity is used to install the battery cell; and

[0007] An air pressure detector is installed outside the battery cavity or on a side wall of the battery cavity, and is used to detect the air pressure of the battery pack.

[0008] In some embodiments, the battery pack further includes: a battery manager, and the air pressure detector is connected to the battery manager.

[0009] In some embodiments, the battery manager includes a circuit board, and the air pressure detector is mounted on the circuit board.

[0010] In some embodiments, the battery pack further includes: a power distribution cavity, and the air pressure detector and the battery manager are both installed in the power distribution cavity.

[0011] In some embodiments, the second installation box includes a side wall, and a detection channel for communicating with the battery cavity is provided on the side wall, and the air inlet of the air pressure detector is connected to the detection channel.

[0012] In some embodiments, the air pressure detector is installed in the detection channel.

[0013] In some embodiments, the air pressure detector is sealed to the detection channel.

[0014] In some embodiments, the battery manager is configured to determine that the battery pack is in a thermal runaway state based on the air pressure detected by the air pressure detector.

[0015] In some embodiments, the battery manager is configured to determine that the battery pack is in a thermal runaway state based on a first air pressure value detected by the air pressure detector.

[0016] In some embodiments, the battery manager is configured to determine that the battery pack is in a thermal runaway state when a first gas pressure value is greater than a first pressure threshold and a duration is greater than a first time threshold.

[0017] In some embodiments, the battery manager is configured to determine that the battery pack is in a thermal runaway state based on a first air pressure change rate of the air pressure detected by the air pressure detector.

[0018] In some embodiments, the battery manager is configured to determine that the battery pack is in a thermal runaway state when a first gas pressure change rate is greater than a first change rate threshold and a duration is greater than a second time threshold.

[0019] In some embodiments, the battery manager is configured to determine that the battery pack is in a thermal runaway state based on a first air pressure value and a first air pressure change rate detected by the air pressure detector.

[0020] In some embodiments, the battery manager is configured to:

[0021] When the first air pressure value is greater than the first pressure threshold and the duration is greater than the first time threshold; and / or

[0022] When the first air pressure change rate is greater than a first change rate threshold and the duration is greater than a second time threshold;

[0023] Determine if the battery pack is in thermal runaway.

[0024] In some embodiments, the first air pressure change rate includes a change rate per unit time and / or a change rate per N unit time, where N is an integer and N>1.

[0025] In some embodiments, the air pressure detector includes: a first processor, wherein the first processor is configured to wake up the battery manager according to the air pressure detected by the air pressure detector.

[0026] In some embodiments, the first processor is configured to wake up the battery manager according to a second air pressure value and / or a second air pressure change rate detected by the air pressure detector.

[0027] In some embodiments, the first processor is configured to:

[0028] When the second air pressure value is greater than the second pressure threshold; and / or

[0029] When the second air pressure change rate is greater than a second change rate threshold;

[0030] Wake up the battery manager.

[0031] In some embodiments, the air pressure detector is used to detect air pressure at a first detection frequency when the battery manager is dormant; and / or

[0032] The air pressure detector is used to detect the air pressure at a second detection frequency when the battery manager is working or awakened;

[0033] The second detection frequency is higher than the first detection frequency.

[0034] In some embodiments, the battery manager is configured to control the air pressure detector to detect the air pressure at a second detection frequency.

[0035] In some embodiments, the battery manager is configured to control the air pressure detector to detect air pressure at a second detection frequency when awakened by the air pressure detector.

[0036] In some embodiments, the air pressure detector is powered by a circuit board of the battery manager.

[0037] In some embodiments, the air pressure detector is connected to the battery manager via a power supply harness and a communication harness.

[0038] In some embodiments, the air pressure detector comprises:

[0039] An air inlet, the air inlet being used for gas to enter the battery pack;

[0040] a protective colloid configured to move under the action of the gas entering the gas inlet;

[0041] A capacitor, comprising an upper capacitor plate and a lower capacitor plate, wherein the upper capacitor plate is connected to the protective colloid; and

[0042] An integrated circuit board is provided on which the lower electrode plate of the capacitor is fixed. The integrated circuit is used to convert the capacitance signal of the capacitor into an air pressure signal and output the air pressure signal.

[0043] In some embodiments, the battery manager is further configured to issue an alarm signal when determining that the battery pack is in a thermal runaway state.

[0044] In the battery pack provided by the embodiment of the present disclosure, the air pressure detector is installed outside the battery cavity or on the side wall of the battery cavity, so that it can be far away from the battery cell. When the battery cell thermal runaway occurs, it will not be damaged before the thermal runaway alarm is triggered, thereby increasing the success rate of the thermal runaway alarm and improving safety.

[0045] The present disclosure also provides a vehicle, comprising: a battery pack as provided in any of the above embodiments.

[0046] The vehicle has the same structure and beneficial effects as described in any of the above embodiments, which will not be repeated here.

[0047] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0049] Figure 1 is a schematic structural diagram of a battery pack according to some embodiments;

[0050] Figure 2 is a schematic structural diagram of an air pressure detector according to some embodiments;

[0051] Figure 3 is a schematic structural diagram of an air pressure detector and a battery manager according to some embodiments;

[0052] Figure 4 is a schematic structural diagram of a battery pack according to some further embodiments;

[0053] Figure 5 is a flow chart of thermal runaway detection of a battery pack according to some embodiments;

[0054] Figure 6 is a graph showing changes in gas pressure of a battery pack according to some embodiments. DETAILED DESCRIPTION

[0055] The following will be combined with the accompanying drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present disclosure.

[0056] In the description of the present disclosure, it should be understood that the terms "upper," "lower," "left," "right," "front," "back," "inner," "outer," and the like, indicating directions or positional relationships, are based on the directions or relative positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present disclosure and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limitations on the present disclosure. Unless otherwise specified, the above-mentioned directional descriptions may be flexibly set in actual application, provided that the relative positional relationships shown in the accompanying drawings are met.

[0057] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this disclosure, unless otherwise specified, "plurality" means two or more.

[0058] In addition, in the specification and claims, "and / or" means at least one of the connected objects, and the character " / " generally indicates that the previous and subsequent related objects are in an "or" relationship.

[0059] In the description of this disclosure, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "electrically connected," and "connected" should be understood broadly. For example, they may refer to fixed electrical connections, detachable electrical connections, or integral electrical connections. They may be directly connected, indirectly connected through an intermediary, or internally connected between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on specific circumstances.

[0060] In the embodiments of the present disclosure, the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, article or device comprising a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, article or device comprising the element. In addition, it should be noted that the scope of the methods and devices in the embodiments of the present disclosure is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0061] In the embodiments of the present disclosure, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present disclosure should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0062] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0063] In some embodiments, as Figure 1-6 As shown, the present disclosure provides a battery pack, comprising:

[0064] A battery cavity, which is used to install the battery cell; and

[0065] Air pressure detector: The air pressure detector is installed outside the battery cavity or on the side wall of the battery cavity. The air pressure detector is used to detect the air pressure of the battery pack.

[0066] Compared with related technologies, thermal runaway detection devices (such as voltage sensors and battery temperature sensors, etc.), the present invention is provided with an air pressure detector. At the same time, the air pressure detector is installed outside the battery cavity or on the side wall of the battery cavity, so as to be away from the battery cell.

[0067] The battery pack provided by the embodiment of the present disclosure installs the air pressure detector outside the battery cavity or on the side wall of the battery cavity, so that it can be far away from the battery cell. When the battery cell thermal runaway occurs, it will not be damaged before the thermal runaway alarm is triggered, thereby increasing the success rate of the thermal runaway alarm and improving safety.

[0068] To facilitate control, in some embodiments, the battery pack further includes a battery manager, and the air pressure detector is connected to the battery manager.

[0069] Generally, a battery manager is provided in the battery pack. By connecting the air pressure detector to the battery manager, the battery manager can be used to determine whether thermal runaway occurs, thereby simplifying the structure and reducing costs.

[0070] The air pressure detector and the battery manager can be connected in a variety of ways. In order to simplify the structure and shorten the thermal runaway alarm time, in some embodiments, the battery manager includes: a circuit board, and the air pressure detector is mounted on the circuit board.

[0071] That is, the air pressure detector can be integrated with the battery manager, thereby facilitating the installation of the air pressure detector and simplifying the structure.

[0072] To facilitate installation of the air pressure detector, in some embodiments, the battery pack further includes: a power distribution cavity, in which the air pressure detector and the battery manager are both installed.

[0073] In some embodiments, the battery pack may include multiple side panels that can be enclosed to form a accommodating cavity. A partition plate can be set in the accommodating cavity, so that it can be divided into a battery cavity and a distribution cavity. The battery cavity is installed with battery cells; the distribution cavity is installed with devices such as a battery manager.

[0074] That is, the present disclosure can install both the air pressure detector and the battery manager in the power distribution cavity, so as to keep them away from the battery cells. When thermal runaway occurs in the battery cells, the gas generated by the thermal runaway will not easily damage the air pressure detector, thereby increasing the success rate of the thermal runaway alarm and improving safety.

[0075] To facilitate air pressure detection, in some embodiments, a detection channel for communicating with the battery cavity is provided on the side wall of the battery cavity, and the air inlet of the air pressure detector is connected to the detection channel.

[0076] In related technologies, the battery cavity and the distribution cavity may be thermally and electrically isolated, and the sealing effect is better. In order to detect the occurrence of thermal runaway in a timely manner, the box where the battery cell is located can be connected to the air pressure detector through a detection channel to facilitate detection and prevent damage to the air pressure detector.

[0077] To facilitate detection, in some embodiments, an air pressure detector is installed in the detection channel.

[0078] In some embodiments, the air pressure detector is sealed to the detection channel.

[0079] In other words, the air pressure detector can be installed in the detection channel and simultaneously achieve a sealed connection. This does not affect thermal runaway detection while ensuring thermal and electrical isolation between the battery cell and the power distribution components, improving safety.

[0080] To facilitate monitoring of thermal runaway phenomena, in some embodiments, the battery manager is configured to determine whether the battery pack is in a thermal runaway state based on the air pressure detected by the air pressure detector.

[0081] That is, the battery manager determines whether thermal runaway occurs through the gas pressure of the battery pack, thereby shortening the thermal runaway detection time and improving safety.

[0082] To facilitate monitoring of thermal runaway phenomena, in some embodiments, the battery manager is configured to determine whether the battery pack is in a thermal runaway state based on a first air pressure value detected by an air pressure detector.

[0083] That is, the battery manager can determine whether thermal runaway occurs based on the first air pressure value of the battery pack. The determination method is simple and direct, and the thermal runaway determination time is effectively shortened.

[0084] To facilitate monitoring of thermal runaway phenomena, in some embodiments, the battery manager is configured to determine that the battery pack is in a thermal runaway state when the first air pressure value is greater than a first pressure threshold and the duration is greater than a first time threshold.

[0085] In order to eliminate detection errors and prevent misjudgment, the battery manager can determine that thermal runaway has occurred when the first air pressure value is greater than the first pressure threshold and the duration is greater than the first time threshold, thereby effectively improving the accuracy of thermal runaway monitoring.

[0086] The first pressure threshold can be any suitable pressure value, such as 115 kPa to 120 kPa. The first pressure threshold can be adjusted accordingly for different altitudes, thereby improving the accuracy of the judgment. The first time threshold can be any reasonable time value, such as 2 seconds to 3 seconds, which can effectively shorten the judgment time while eliminating errors.

[0087] To facilitate monitoring of thermal runaway phenomena, in some embodiments, the battery manager is configured to determine whether the battery pack is in a thermal runaway state based on a first air pressure change rate detected by the air pressure detector.

[0088] In order to eliminate detection errors and prevent misjudgment, in some embodiments, the battery manager is used to determine that the battery pack is in a thermal runaway state when the first air pressure change rate is greater than a first change rate threshold and the duration is greater than a second time threshold.

[0089] Those skilled in the art can set appropriate first rate of change thresholds and second time thresholds to improve the accuracy of thermal runaway monitoring. The first rate of change threshold can be various suitable rate of change values, such as 2 kPa / s to 4 kPa / s, and the second time threshold can be various reasonable time values, such as 2 seconds to 3 seconds. This can effectively shorten the judgment time while eliminating errors.

[0090] To facilitate monitoring of thermal runaway phenomena, in some embodiments, the battery manager is configured to determine whether the battery pack is in a thermal runaway state based on a first air pressure value and a first air pressure change rate detected by the air pressure detector.

[0091] That is, whether thermal runaway occurs can be determined by combining the first air pressure value and the first air pressure change rate, thereby further shortening the thermal runaway determination time and improving safety.

[0092] To eliminate detection errors and prevent misjudgment, in some embodiments, the battery manager is used to:

[0093] When the first air pressure value is greater than the first pressure threshold and the duration is greater than the first time threshold; and / or

[0094] When the first air pressure change rate is greater than a first change rate threshold and the duration is greater than a second time threshold;

[0095] Determine if the battery pack is in thermal runaway.

[0096] That is, whether thermal runaway occurs can be determined by the first air pressure value and the first air pressure change rate, thereby effectively shortening the determination time and improving the accuracy of the determination.

[0097] In order to effectively determine the occurrence of thermal runaway, in some embodiments, the first air pressure change rate includes a change rate per unit time and / or a change rate per N unit time, where N is an integer and N>1.

[0098] That is, the first air pressure change rate can be 2kpa / s to 4kpa / s, or 3kpa / 10s to 5kpa / 10s. For the case where the battery pack has a low state of charge, the occurrence of thermal runaway can be effectively judged by the change rate of N unit times, thereby preventing the occurrence of missed reports and effectively improving the accuracy and timeliness of thermal runaway alarms.

[0099] In order to reduce energy consumption and monitor thermal runaway in a timely and accurate manner, in some embodiments, the air pressure detector includes: a first processor, and the first processor is used to wake up the battery manager according to the air pressure detected by the air pressure detector.

[0100] That is, the air pressure detector can determine whether it is necessary to wake up the battery manager according to the detected air pressure to further determine whether thermal runaway occurs.

[0101] To facilitate control, in some embodiments, the first processor is configured to wake up the battery manager according to a second air pressure value and / or a second air pressure change rate detected by the air pressure detector.

[0102] That is, the first processor may wake up the battery manager according to the second air pressure value and / or the second air pressure change rate, thereby being able to simply and directly determine whether the battery manager needs to be woken up.

[0103] To eliminate detection errors and prevent misjudgment, in some embodiments, the first processor is configured to:

[0104] When the second air pressure value is greater than the second pressure threshold; and / or

[0105] When the second air pressure change rate is greater than a second change rate threshold;

[0106] Wake up the battery manager.

[0107] Those skilled in the art can set appropriate second pressure thresholds and second change rate thresholds to improve the accuracy of wake-up determination. The second pressure threshold can have various suitable pressure values, such as 108kPa to 114kPa; the second change rate threshold can have various suitable change rate values, such as 1kPa / s to 1.5kPa / s, thereby eliminating errors and effectively shortening the determination time.

[0108] To reduce power consumption, in some embodiments, the air pressure detector is configured to detect air pressure at a first detection frequency when the battery manager is in sleep mode; and / or

[0109] The air pressure detector is used to detect the air pressure at a second detection frequency when the battery manager is working or awakened;

[0110] The second detection frequency is higher than the first detection frequency.

[0111] That is, in different states, the air pressure detector can perform detection at different frequencies, thereby effectively reducing power consumption and, at the same time, ensuring the timeliness of detection.

[0112] To facilitate control, in some embodiments, the battery manager is configured to control the air pressure detector to detect the air pressure at a second detection frequency.

[0113] That is, the detection frequency of the air pressure detector can be controlled by the battery manager to adapt to different working states.

[0114] To facilitate control, in some embodiments, the battery manager is configured to control the air pressure detector to detect air pressure at a second detection frequency when awakened by the air pressure detector.

[0115] That is, when the air pressure detector wakes up the battery manager, the battery manager can control the detector to detect the air pressure at the second detection frequency, so that the occurrence of thermal runaway can be detected in time, thereby improving safety.

[0116] To facilitate operation, in some embodiments, the air pressure detector is powered by the circuit board of the battery manager. That is, the air pressure detector can be powered by the battery manager, thereby eliminating the need for a separate power supply, simplifying the structure, and reducing costs.

[0117] To facilitate connection, in some embodiments, the air pressure detector is connected to the battery manager via a power supply harness and a communication harness.

[0118] When the air pressure detector is set in the detection channel, the air pressure detector is connected to the battery manager through the power supply harness and the communication harness, thereby facilitating operation.

[0119] The air pressure detector may be any suitable air pressure detection device, such as a capacitive pressure sensor. To facilitate detection of the air pressure of the battery pack, in some embodiments, the air pressure detector includes:

[0120] Air inlet: The air inlet is used for gas to enter the battery pack;

[0121] A protective colloid, which is used to move under the action of the gas entering the air inlet;

[0122] A capacitor, comprising an upper plate and a lower plate, wherein the upper plate is connected to the protective colloid; and

[0123] The integrated circuit board is fixed with the lower plate of the capacitor on the integrated circuit board. The integrated circuit is used to convert the capacitance signal of the capacitor into an air pressure signal and output it.

[0124] When thermal runaway occurs in the battery cell, the gas in the battery pack (including the original gas in the battery pack and the gas generated by thermal runaway) can drive the protective colloid to move, thereby changing the capacitance signal and realizing the detection of air pressure. The structure is simple and direct.

[0125] To improve safety, in some embodiments, the battery manager is further configured to issue an alarm signal when it determines that the battery pack is in a thermal runaway state.

[0126] That is, when thermal runaway is determined to have occurred, an alarm signal can be issued in a timely manner, thereby reminding the user to stay away in time and improve safety.

[0127] The battery pack provided by the embodiment of the present disclosure installs the air pressure detector outside the battery cavity or on the side wall of the battery cavity, so that it can be far away from the battery cell. When the battery cell thermal runaway occurs, it will not be damaged before the thermal runaway alarm is triggered, thereby increasing the success rate of the thermal runaway alarm and improving safety.

[0128] In some embodiments, the present disclosure provides a battery pack, such as Figure 1 As shown, it includes: a battery cavity 11 and a power distribution cavity 12, and a BMC (Battery Management Controller) control board 2 is placed in the power distribution cavity 12;

[0129] In some embodiments, as Figure 1 As shown, the air pressure sensor chip is integrated into the BMC control board 2. Figure 2As shown, the air pressure sensor chip includes a pressure injection port 211, a protective colloid 212, a vacuum cavity 213 and an ASIC circuit (Application Specific Integrated Circuit) 214. When the air pressure increases, the air pressure squeezes the protective colloid 212 through the pressure injection port 211 to make it move downward. The vacuum cavity 213 can be equivalent to a capacitor plate. The upper plate of the capacitor is connected to the protective colloid 212, and the lower plate of the capacitor is fixed. When the protective colloid 212 moves downward, it drives the upper plate of the capacitor in the vacuum cavity 213 to move downward. Therefore, the distance between the upper and lower plates of the capacitor decreases, and the capacitance value increases. Then, the capacitance signal is converted into an air pressure signal and output through the ASIC circuit 214. When the air pressure decreases, similarly, the protective colloid 212 drives the upper plate of the capacitor in the vacuum cavity 213 to move upward. Therefore, the distance between the upper and lower plates of the capacitor increases, and the capacitance value decreases. Then, the capacitance signal is converted into an air pressure signal and output through the ASIC circuit 214.

[0130] like Figure 3 As shown, the pressure sensor chip is powered by the SBC power chip (System Basis Chip) on the BMC control board 2, which is generally 3.3V or 5V. The pressure sensor chip can communicate with the MCU (Microcontroller Unit) on the BMC control board 2 via I2C or SPI. When the BMC is dormant, the pressure sensor chip will enter a low-power mode, the pressure sampling frequency will be reduced, and the collected pressure data will not be sent to the MCU. However, the pressure sensor chip can also be integrated with an MCU to support reverse wake-up of the MCU. When the detected pressure value or pressure change exceeds a certain threshold, the MCU can be woken up through a hard line or a specific communication protocol. After the MCU is woken up, the pressure sensor chip will immediately enter the working mode, increase the pressure sampling frequency, and send the pressure value to the MCU in real time to determine whether a thermal runaway alarm has occurred. The duration can be 10 minutes. If no battery cell thermal runaway signal is detected within 10 minutes, the MCU will continue to enter the dormant state and the pressure sensor chip will also enter the low-power mode.

[0131] In some embodiments, considering that the battery cavity and the distribution cavity in some battery packs have achieved thermal and electrical isolation and good sealing effect, under this battery pack structure, when the battery cell thermal runaway occurs, the air pressure in the battery cavity rises sharply. When the air pressure reaches the opening pressure of the explosion-proof valve, the air pressure will be released. Since the sealing between the battery cavity and the distribution cavity is good, the air pressure change in the distribution cavity is not obvious at this time, and the thermal runaway alarm cannot be realized. Therefore, this solution needs to be optimized. Figure 4As shown, a through hole can be opened between the battery cavity and the power distribution cavity. The air pressure sensor chip can be made into a small plate fixed on a connector 21 with good sealing performance. The connector is placed in the through hole. At this time, the air pressure sensor is located in the battery cavity and can sense the air pressure changes in the battery cavity in real time. The air pressure sensor small board 21 is connected to the BMC control board 2 through a connector and a wiring harness 22. The wiring harness 22 includes a power supply line for the air pressure sensor chip and a communication line with the MCU.

[0132] like Figure 5 As shown, the thermal runaway alarm strategy process provided by the present disclosure is as follows: when the BMC is in sleep state, the MCU sends a specific communication protocol to control the air pressure sensor chip to enter low power consumption mode. In this mode, the frequency of the air pressure sensor chip collecting air pressure is reduced, and it can be collected once per second. The collected air pressure data is not sent to the MCU, and the MCU built into the air pressure sensor chip determines whether the conditions for reversely waking up the MCU are met.

[0133] In low power mode, when the pressure sensor chip detects that the current air pressure value is greater than or equal to the range of 108kPa to 114kPa, and / or the air pressure change rate is greater than or equal to the range of 1kPa / s to 1.5kPa / s, the pressure sensor chip will reversely wake up the BMC by hard-wiring or using a specific communication protocol.

[0134] When the BMC wakes up, it immediately sends a command to the air pressure sensor chip to enter high power mode. The sampling frequency of the air pressure sensor chip in high power mode is increased to collect air pressure every 100ms and transmit the data to the MCU in real time. The MCU uses the collected air pressure data to determine whether thermal runaway of the battery cell has occurred.

[0135] When the MCU performs thermal runaway judgment, it can use two modes: absolute value of air pressure and rate of change of air pressure.

[0136] In the absolute value judgment mode of air pressure, when the air pressure value received by the MCU is greater than the range of 115kPa to 120kPa, the duration is recorded. When the duration is 1s, considering that the air pressure sensor chip may have occasional sampling abnormalities, the fault bit is judged to be 0. When it lasts for 2s, the fault bit accumulates to 1. When it lasts for 3s, the fault bit accumulates to 2. At this time, the MCU sends an alarm signal and transmits the signal to the vehicle VCU. The alarm signal is displayed on the instrument or on-board display to inform the driver to immediately stay away from the vehicle.

[0137] In the air pressure change rate judgment mode, when the air pressure change rate received by the MCU is greater than the range of 2kPa / s to 4kPa / s, and the duration is 1s, the fault bit is 1, and the duration is 2s, the fault bit is 2, and the MCU issues an alarm signal; when the air pressure change rate received by the MCU is greater than the range of 3kPa / 10s to 5kPa / 10s, and the duration is 1s, the fault bit is 0, the duration is 2s, and the duration is 3s, the fault bit is 2, and the MCU issues an alarm signal;

[0138] When the MCU is making a thermal runaway determination, the absolute value of the air pressure and the air pressure change rate determination can be performed simultaneously. When the fault bit is 1, if the fault bit does not increase for more than 5 seconds, the MCU will reset the fault bit to zero.

[0139] like Figure 6 As shown, the air pressure changes during thermal runaway of four different battery packs collected by the disclosed solution are basically consistent. The rate of change of the air pressure is high in the first second of the rise, and then it rises steadily. If another battery cell continues to thermally runaway, there will be a stage of rapid pressure rise for one or two seconds, and then the air pressure continues to rise steadily.

[0140] As shown in Table 1 below, Figure 6 According to the actual data of the medium pressure curve and the thermal runaway alarm strategy provided by the present invention, the four thermal runaway battery packs can reach the alarm condition within 1 minute of the occurrence of thermal runaway. The scheme and strategy proposed in the present invention can achieve a rapid response to the thermal runaway of the battery cell, and do not need to rely on conditions such as battery cell temperature and voltage to coordinate the alarm.

[0141] Time(s) 1#(kpa) 2#(kpa) 3#(kpa) 4#(kpa) 1 100.3 97.4 103 100.3 2 105.1 103.6 105.7 104.6 3 105.3 104.2 106.5 104.4 4 105.5 105.7 107.5 104.6 5 105.9 107.1 108.4 105.5 6 107.5 108.6 109.4 106.5 7 109.2 110 110.4 107.7 8 110 111.9 111.4 108.6 9 111 113.7 112.5 109.6 10 111.2 117.6 113.3 110.6 11 111.7 120.1 114.3 111.4 12 112.1 121.7 115.2 112.7 13 112.5 123.2 115.6 113.9 14 112.7 123.6 116 114.9 15 113.1 124 116.4 116.2 16 113.7 124.6 116.7 117.2 17 114.1 125.2 117 118

[0142] Table 1: Data table of gas pressure of four battery packs with thermal runaway in the embodiments of the present disclosure. The present disclosure also provides a vehicle, which includes: a battery pack as provided in any of the above embodiments.

[0143] The vehicle has the same structure and beneficial effects as any of the above embodiments, which will not be described again here.

[0144] The embodiments of the present disclosure are described above in conjunction with the accompanying drawings, but the present disclosure is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present disclosure, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present disclosure and the claims, all of which are protected by the present disclosure.

Claims

1. A battery pack, characterized in that: include: A battery cavity, wherein the battery cavity is used to install the battery cell; as well as An air pressure detector is installed outside the battery cavity or on a side wall of the battery cavity, and is used to detect the air pressure of the battery pack.

2. The battery pack according to claim 1, wherein: The battery pack further includes a battery manager, and the air pressure detector is connected to the battery manager.

3. The battery pack according to claim 2, wherein: The battery manager includes a circuit board, and the air pressure detector is mounted on the circuit board.

4. The battery pack according to claim 2, wherein: The battery pack further includes: a power distribution cavity, in which the air pressure detector and the battery manager are both installed.

5. The battery pack according to claim 2, wherein: The side wall is provided with a detection channel for communicating with the battery cavity, and the air inlet of the air pressure detector is communicated with the detection channel.

6. The battery pack according to claim 5, characterized in that: The air pressure detector is installed in the detection channel.

7. The battery pack according to claim 6, characterized in that: The air pressure detector is sealed and connected to the detection channel.

8. The battery pack according to claim 2, wherein: The battery manager is used to determine whether the battery pack is in a thermal runaway state according to the air pressure detected by the air pressure detector.

9. The battery pack according to claim 8, characterized in that: The battery manager is configured to determine that the battery pack is in a thermal runaway state according to a first air pressure value detected by the air pressure detector.

10. The battery pack according to claim 9, characterized in that: The battery manager is configured to determine that the battery pack is in a thermal runaway state when a first air pressure value is greater than a first pressure threshold and the duration is greater than a first time threshold.

11. The battery pack according to claim 8, characterized in that: The battery manager is configured to determine that the battery pack is in a thermal runaway state according to a first air pressure change rate of the air pressure detected by the air pressure detector.

12. The battery pack according to claim 11, wherein: The battery manager is configured to determine that the battery pack is in a thermal runaway state when a first air pressure change rate is greater than a first change rate threshold and a duration is greater than a second time threshold.

13. The battery pack according to claim 8, wherein: The battery manager is configured to determine that the battery pack is in a thermal runaway state based on a first air pressure value and a first air pressure change rate detected by the air pressure detector.

14. The battery pack according to claim 13, wherein: The battery manager is used to: When the first air pressure value is greater than the first pressure threshold and the duration is greater than the first time threshold; and / or When the first air pressure change rate is greater than a first change rate threshold and the duration is greater than a second time threshold; Determine if the battery pack is in thermal runaway.

15. The battery pack according to claim 12 or 14, characterized in that: The first air pressure change rate includes a change rate per unit time and / or a change rate per N unit time, where N is an integer and N>1.

16. The battery pack according to claim 2, wherein: The air pressure detector includes a first processor, and the first processor is configured to wake up the battery manager according to the air pressure detected by the air pressure detector.

17. The battery pack according to claim 16, wherein: The first processor is configured to wake up the battery manager according to a second air pressure value and / or a second air pressure change rate detected by the air pressure detector.

18. The battery pack according to claim 17, characterized in that: The first processor is configured to: When the second air pressure value is greater than the second pressure threshold; and / or When the second air pressure change rate is greater than a second change rate threshold; Wake up the battery manager.

19. The battery pack according to claim 2, wherein: The air pressure detector is used to detect the air pressure at a first detection frequency when the battery manager is dormant; and / or The air pressure detector is used to detect the air pressure at a second detection frequency when the battery manager is working or awakened; The second detection frequency is higher than the first detection frequency.

20. The battery pack according to claim 19, wherein: The battery manager is used to control the air pressure detector to detect the air pressure at a second detection frequency.

21. The battery pack according to claim 19, wherein: The battery manager is configured to control the air pressure detector to detect air pressure at a second detection frequency when awakened by the air pressure detector.

22. The battery pack according to claim 3, characterized in that: The air pressure detector is powered by a circuit board of the battery manager.

23. The battery pack according to claim 5, characterized in that: The air pressure detector is connected to the battery manager via a power supply harness and a communication harness.

24. The battery pack according to claim 1, wherein: The air pressure detector comprises: An air inlet, the air inlet being used for gas to enter the battery pack; a protective colloid configured to move under the action of the gas entering the gas inlet; A capacitor, comprising an upper capacitor plate and a lower capacitor plate, wherein the upper capacitor plate is connected to the protective colloid; and An integrated circuit board is provided on which the lower electrode plate of the capacitor is fixed. The integrated circuit is used to convert the capacitance signal of the capacitor into an air pressure signal and output the air pressure signal.

25. The battery pack according to claim 8, characterized in that: The battery manager is further configured to send an alarm signal when determining that the battery pack is in a thermal runaway state.

26. A vehicle, characterized in that: A battery pack comprising any one of claims 1-25.

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