Battery pack liquid leakage detection method and device, energy storage system, electronic equipment and storage medium

Abstract

The invention discloses a battery pack liquid leakage detection method and device, an energy storage system, electronic equipment and a storage medium. The method comprises the steps that first parameter information of cells in a battery pack is determined, the first parameter information is used for indicating internal resistance data of the cells in the battery pack, and a plurality of cells are configured in the battery pack; second parameter information of a battery cell in the battery pack is determined, the second parameter information is used for indicating pressure data collected by a pressure sensor arranged on the battery cell in the battery pack, and the pressure sensor is used for responding to pressure generated by electrolyte leaked from the battery cell on the surface of the pressure sensor; and according to the first parameter information and the second parameter information, carrying out liquid leakage detection on the battery cell in the battery pack. According to the scheme of the invention, the leakage battery cell in the battery pack can be accurately positioned, and rapid early warning response can be carried out for the leakage battery cell to ensure the safety and reliability of equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy, and particularly to a method and device for detecting battery pack leakage, an energy storage system, an electronic device, and a storage medium. Background Art

[0002] With the development of electrochemical energy storage technology, lithium-ion batteries are widely used in energy storage power supplies, electric vehicles, and various electronic devices. As a component of lithium-ion battery energy devices, the stability and safety of the electrolyte directly determine the performance and reliability of the devices. However, during battery manufacturing, transportation, use, or aging, the electrolyte may leak due to reasons such as seal failure, mechanical damage, abnormal internal pressure, or internal electrochemical corrosion, which not only leads to a decline in battery performance but may also pose serious safety hazards. Therefore, for the problem of electrolyte leakage in battery packs, a method that can accurately detect the leaking battery cells is needed to ensure the safety and reliability of the devices. Summary of the Invention

[0003] The present invention provides a method and device for detecting battery pack leakage, an energy storage system, an electronic device, and a storage medium to accurately locate the leaking battery cells in the battery pack and quickly give an early warning response to the leaking battery cells to ensure the safety and reliability of the devices.

[0004] According to one aspect of the present invention, a method for detecting battery pack leakage is provided. The method includes:

[0005] Determine the first parameter information of the battery cells in the battery pack, where the first parameter information is used to indicate the internal resistance data of the battery cells in the battery pack, and a plurality of battery cells are configured in the battery pack;

[0006] Determine the second parameter information of the battery cells in the battery pack, where the second parameter information is used to indicate the pressure data collected by the pressure sensors arranged on the battery cells, and the pressure sensors are used to respond to the pressure generated by the leaked electrolyte on the surface of the pressure sensors;

[0007] Detect the leakage of the battery cells in the battery pack according to the first parameter information and the second parameter information.

[0008] According to another aspect of the present invention, a device for detecting battery pack leakage is provided. The device includes:

[0009] A first determination module for determining the first parameter information of the battery cells in the battery pack, where the first parameter information is used to indicate the internal resistance data of the battery cells in the battery pack, and a plurality of battery cells are configured in the battery pack;

[0010] A second determination module, configured to determine second parameter information of the battery cells in the battery pack, where the second parameter information is used to indicate pressure data collected by pressure sensors arranged on the battery cells in the battery pack, and the pressure sensors are configured to respond to the pressure generated by the leaked electrolyte in the battery cells on the surfaces of the pressure sensors;

[0011] A detection module, configured to perform leakage detection on the battery cells in the battery pack according to the first parameter information and the second parameter information.

[0012] According to another aspect of the present invention, there is provided an energy storage system, including: at least one battery module; at least one battery management system, where the at least one battery management system corresponds to the at least one battery module one by one, the battery management system is electrically connected to the corresponding battery module, and the battery management system is configured to execute the battery pack leakage detection method according to any embodiment of the present invention.

[0013] According to another aspect of the present invention, there is provided an electronic device, where the electronic device includes:

[0014] At least one processor; and

[0015] A memory communicatively connected to the at least one processor; where

[0016] The memory stores a computer program executable by the at least one processor, and when the computer program is executed by the at least one processor, the at least one processor is enabled to execute the battery pack leakage detection method according to any embodiment of the present invention.

[0017] According to another aspect of the present invention, there is provided a computer-readable storage medium, where the computer-readable storage medium stores computer instructions, and the computer instructions are used to implement the battery pack leakage detection method according to any embodiment of the present invention when executed by a processor.

[0018] According to another aspect of the present invention, there is provided a computer program product, where the computer program product includes a computer program, and the computer program implements the battery pack leakage detection method according to any embodiment of the present invention when executed by a processor.

[0019] In the technical solution of the embodiment of the present invention, the pressure sensor of the battery cells in the battery pack can directly sense the pressure change caused by the electrolyte leakage to the surface of the pressure sensor. The pressure sensor is sensitive to the pressure generated by the electrolyte on its surface. Even a small amount of electrolyte leakage may cause the response of the pressure sensor. By combining the internal resistance data of the battery cells that can reflect the internal state of the battery cells in the battery pack, the detection ability for small amount of liquid leakage can be improved, and it can quickly sense and analyze and judge when the electrolyte leaks. Once an abnormality is detected, the electrolyte leakage situation can be quickly discovered and responded to, and it can more accurately determine which specific battery cell has leaked liquid, realizing accurate positioning. At the same time, due to the combination of two different types of parameter information, detection and analysis are carried out from two perspectives of the internal state of the battery cells and the external pressure change. The different parameter information can corroborate and complement each other, reducing the possibility of misjudgment caused by special circumstances or interference of a single parameter, improving the accuracy and reliability of the detection result, being able to reduce the influence of the environmental state on the detection result, and improving the accuracy and reliability of the battery cell liquid leakage detection.

[0020] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is a flowchart of a method for detecting battery pack liquid leakage provided according to an embodiment of the present invention;

[0023] Figure 2 is a flowchart of another method for detecting battery pack liquid leakage provided according to an embodiment of the present invention;

[0024] Figure 3 is a schematic diagram of arranging a thin film pressure sensor on a battery cell during the detection of battery pack liquid leakage applicable to an embodiment of the present invention;

[0025] Figure 4 is a flowchart of yet another method for detecting battery pack liquid leakage provided according to an embodiment of the present invention;

[0026] Figure 5 is a schematic structural diagram of a device for detecting battery pack liquid leakage provided according to an embodiment of the present invention;

[0027] Figure 6It is a schematic structural diagram of an electronic device for implementing the battery pack leakage detection method according to an embodiment of the present invention. Detailed implementation manners

[0028] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0030] Figure 1 A flowchart of a battery pack leakage detection method is provided for an embodiment of the present invention. This embodiment is applicable to the situation where the battery cells in the battery pack in the energy storage system leak liquid and can be detected in a timely and accurate manner. This method can be executed by a battery pack leakage detection device, which can be implemented in the form of hardware and / or software, and the battery pack leakage detection can be configured in any electronic device with network communication functions.

[0031] As Figure 1 shown, the battery pack leakage detection method of this embodiment includes the following processes:

[0032] S110. Determine the first parameter information of the battery cells in the battery pack. The first parameter information is used to indicate the internal resistance data of the battery cells in the battery pack, and several battery cells are configured in the battery pack.

[0033] The energy storage system may include at least one battery module and at least one battery management system. The at least one battery management system corresponds to the at least one battery module one by one, and the battery management system is electrically connected to the corresponding battery module. The battery management system can be used to execute, but is not limited to, the battery pack leakage detection method provided in this embodiment.

[0034] The battery pack of the energy storage system may include at least one battery module, and several battery cells may be included in the battery module. The battery module may connect multiple battery cells together in a series, parallel or series-parallel combination manner and be equipped with a corresponding battery management system (BMS). For example, the battery module may be composed of several lithium-ion battery cells, and the battery cells are neatly arranged in a metal or plastic housing, and electrical connection is achieved through connecting components. Among them, the connecting components may include but are not limited to at least one of battery connecting wires and electrode terminals, which are used to achieve electrical connection between battery cells and between the battery pack and external devices. The connecting components have good electrical conductivity and mechanical strength to ensure stable transmission of current and reliability of connection.

[0035] The battery cells in the battery pack are responsible for storing and releasing electrical energy. The battery cells constitute the smallest rechargeable and dischargeable unit of the battery. The internal structure of the battery cells may include a positive electrode, a negative electrode, a separator, and an electrolyte, and the storage and release of electrical energy are achieved through chemical reactions between these components. For example, the types of battery cells may include but are not limited to at least one of the following: lithium-ion batteries, nickel-metal hydride batteries, lead-acid batteries, etc. Different types of battery cells have different performances; for example, different types of battery cells have differences in at least one of the performances of energy density, cycle life, and charge-discharge efficiency.

[0036] The battery pack may further combine multiple battery modules together and integrate components such as a battery management system, a cooling system, an electrical connection system, and a housing to form a complete energy storage device that can be directly used for device power supply. For example, the battery pack of an outdoor energy storage system or an indoor energy storage system may install multiple battery modules in a larger metal housing, and cooling pipes are provided inside to ensure that the battery maintains an appropriate temperature during the charging and discharging process. At the same time, the battery management system will monitor and manage each battery module in real time. Among them, the housing is used to protect the battery cells and other components inside the battery pack and can be made of high-strength, flame-retardant, and insulating materials such as plastics and aluminum alloys. The housing needs to have good sealing performance to prevent dust, moisture, etc. from entering the inside of the battery pack and affecting the battery performance and safety.

[0037] The battery pack realizes the storage and release of electrical energy through chemical reactions inside the battery cells. During the charging process, the electrical energy provided by the external power supply causes chemical substances inside the battery cells to undergo oxidation-reduction reactions, converting the electrical energy into chemical energy and storing it in the battery cells. During the discharging process, the chemical substances inside the battery cells react again, converting the chemical energy into electrical energy and outputting it to external devices through the connecting components.

[0038] The battery pack of this embodiment can be implemented in but not limited to the following configurations: the battery pack is configured in an electric vehicle, the battery pack is configured in an energy storage system, and the battery pack is configured in a portable device. Among them, when the battery pack is configured in an electric vehicle, the battery pack can provide electrical energy for the drive motor of the electric vehicle, determining the driving range and power performance of the electric vehicle. When the battery pack is configured in an energy storage system, the battery pack is used to store the excess electrical energy generated by renewable energy power generation systems such as solar energy and wind energy, and release electrical energy during peak electricity consumption or insufficient energy supply. When the battery pack is configured in a portable device, such as terminal devices like mobile phones, laptops, and tablets, the battery pack provides electrical energy for the terminal device.

[0039] The internal resistance of the battery cell can be the resistance that the battery cell presents to the current in the working state, and the battery cell internal resistance can be used to measure the performance of the battery cell. The battery cell internal resistance is related to at least one of the material characteristics of the battery cell, the battery cell structure, the charge and discharge state, and the temperature. Among them, different electrode materials and electrolytes have different electrical conductivity and electrochemical properties. The structural design of the battery cell, such as the thickness of the electrode, the type and thickness of the separator, and the compaction density of the electrode sheet, will also affect the battery cell internal resistance.

[0040] The battery cell internal resistance can include but not limited to the DC internal resistance and the AC internal resistance. The AC internal resistance is the resistance that the battery cell presents to the alternating current, usually represented in complex form, including a real part and an imaginary part. The real part mainly corresponds to the ohmic resistance, reflecting the resistance characteristics of the conductive materials and electrolytes inside the battery cell, and following Ohm's law. The imaginary part is mainly related to the characteristics of capacitance, inductance, etc. inside the battery cell and the kinetic process of the electrochemical reaction, reflecting the non-ohmic characteristics of the battery cell under alternating current signals and being related to the polarization phenomenon.

[0041] The DC internal resistance can refer to the resistance presented by the battery cell when a direct current passes through the battery cell. The DC internal resistance is the resistance value shown by the resistance of the battery cell to the current inside the battery cell when a direct current passes through. The DC internal resistance not only includes the ohmic resistance inside the battery cell, but also includes the increase in resistance caused by the polarization phenomenon, and is also closely related to factors such as the state of charge, temperature, and charge and discharge rate of the battery cell. The DC internal resistance of the battery is mainly determined by factors such as electrode materials, electrolytes, separators, and the structure of the battery. When a direct current passes through the battery, an electrochemical reaction will occur at the interface between the electrode and the electrolyte, generating a charge transfer resistance; at the same time, the ions in the electrolyte will be subject to resistance during migration, forming an ion conduction resistance.

[0042] The battery cell stores electrolyte internally. The electrolyte contains a large number of mobile ions, which play a key role in charge conduction during the electrochemical reaction of the battery cell. Their conductivity directly affects the efficiency of ion transport inside the battery cell. When the battery cell experiences liquid leakage, it means the loss of electrolyte. As the amount of electrolyte decreases, the number of carriers participating in ion conduction decreases. At the same time, liquid leakage will also cause changes in the chemical environment inside the battery cell, such as introducing impurities, further interfering with the normal conduction of ions. The combined effect of these factors significantly reduces the ionic conductivity of the battery cell.

[0043] The decrease in the ionic conductivity inside the battery cell will directly lead to an increase in the internal resistance of the battery cell. From a microscopic perspective, the ion conduction is blocked, making it more difficult for electrons to move inside the battery cell, which macroscopically manifests as an increase in the internal resistance of the battery cell. The increase in the internal resistance of the battery cell will not only exacerbate the energy loss during the charge and discharge processes of the battery cell, resulting in obvious heating of the battery cell and shortening the service life of the battery cell, but also affect the overall performance consistency of the battery pack. If the internal resistance differences among multiple battery cells in the battery pack continue to expand due to liquid leakage problems, it will cause uneven voltage and current distribution among the battery cells during charge and discharge, and in severe cases, it may even cause individual battery cells to be overcharged or over-discharged, posing a great threat to the safe operation of the battery pack.

[0044] Therefore, in this application solution, considering that the battery pack consists of multiple battery cells working together, and the internal resistance situation of each battery cell affects the overall performance, as well as the change in internal resistance after liquid leakage of the battery cell, it is possible to use the internal resistance of the battery pack battery cells to evaluate whether there is electrolyte leakage in the battery cell. The internal resistance data of the battery cells can be used to evaluate the health status of the battery cells in the battery pack. If the internal resistance value of one battery cell in the battery pack shows an abnormal increase, it means that there is a high probability of electrolyte dry-out inside the battery cell, that is, there is an electrolyte leakage problem, and corresponding measures need to be taken in a timely manner for maintenance or replacement of the battery cell to avoid negative impacts on the performance and safety of the entire battery pack.

[0045] S120. Determine the second parameter information of the battery cells in the battery pack. The second parameter information is used to indicate the pressure data collected by the pressure sensors arranged on the battery cells in the battery pack. The pressure sensors are used to respond to the pressure generated by the leaked electrolyte on the surface of the pressure sensors in the battery cells.

[0046] The pressure sensors arranged on the battery cells are used to detect and measure the pressure generated on the surface of the pressure sensors in the case of electrolyte leakage in the battery cells. Specifically, the external force is received on the surface of the pressure sensors. Since the pressure generated by the leaked electrolyte in the battery cells is essentially a kind of external force, the pressure generated by the leaked electrolyte in the battery cells can be quantified and signal-converted.

[0047] When the pressure generated by the leaked electrolyte in the battery cell acts on the pressure sensor, the sensitive element inside the pressure sensor arranged on the battery cell will undergo physical changes, such as deformation, resistance change, capacitance change, etc. These changes will cause changes in the electrical signal. By measuring and analyzing the electrical signal, the magnitude and / or pressure change trend of the pressure generated by the leaked electrolyte in the battery cell can be known. For this reason, when judging whether there is liquid leakage in the battery cell of the battery pack in this application, the pressure data generated by the leaked electrolyte of the battery cell in the battery pack on the surface of the pressure sensor can also be referred to.

[0048] Optionally, the first parameter information is used to indicate the magnitude of the DC internal resistance of the battery cell in the battery pack and / or the change trend of the DC internal resistance of the battery cell.

[0049] The inside of the battery pack is composed of multiple battery cells closely combined. When the battery cells are working normally, the internal electrolyte is sealed in a specific space and participates in the electrochemical reaction to achieve the storage and release of electrical energy. However, due to various factors, such as manufacturing process defects of the battery cells, aging caused by long-term use, external physical impacts, etc., the battery cells may leak liquid. Once the electrolyte leaks, it will spread on the surface of the battery cells inside the battery pack. When it comes into contact with the pressure sensor pre-arranged on the battery cell, the leaked electrolyte of the battery cell will generate pressure on the surface of the sensor, realizing the perception of subtle changes in the state of the battery cell.

[0050] The pressure sensor has a sensitive pressure sensing element. When the leaked electrolyte in the battery cell contacts the surface of the sensor, the gravity of the electrolyte itself and the impact force generated by the flow, etc., will exert a force on the sensing element of the pressure sensor. This force will cause the sensing element to undergo physical deformation, such as changing its resistance value, capacitance value or generating a piezoelectric effect, etc. The specific form of change depends on the working principle type of the pressure sensor. For example, in a common piezoresistive pressure sensor, the resistance of the sensing element will change due to the pressure, thereby causing changes in the current or voltage in the circuit; the capacitive pressure sensor changes the capacitance value by changing the distance between the capacitor plates due to pressure. The pressure sensor quickly converts this physical quantity change caused by the electrolyte pressure into an electrical signal output.

[0051] The DC internal resistance of the battery cell is an index to measure the performance of the battery cell. When the current passes through the battery cell in the battery pack in the form of direct current, the degree of obstruction of the battery cell to the current is the DC internal resistance. The magnitude of the DC internal resistance of the battery cell involved in the first parameter information intuitively reflects the obstruction status of the internal structure and chemical substance state of the battery cell to current conduction. For example, if the DC internal resistance of a battery cell in the battery pack is greater than the preset threshold, it means that the electrolyte inside the battery cell has leaked, resulting in a decline in the performance of the electrolyte and a weakening of the ion conduction ability, thereby causing an increase in the overall DC internal resistance of the battery cell. The greater the magnitude of the DC internal resistance of the battery cell involved in the first parameter information, the more the electrolyte leakage amount of the battery cell in the battery pack.

[0052] The change trend of the DC internal resistance of the battery cell involved in the first parameter information can reflect the dynamic development trend of the DC internal resistance over a period of time, as the battery cell undergoes multiple charge and discharge cycles, changes in the ambient temperature and other factors. For example, after multiple consecutive charge and discharge cycles, if the first parameter information shows that the DC internal resistance of the battery cell shows a continuous upward trend, it means that the battery cell is gradually moving towards the aging stage. Because during the charge and discharge process, electrolyte leakage may occur inside the battery cell, and as the electrolyte leaks, the internal resistance characteristics of the battery cell will gradually change, causing the DC internal resistance to continue to rise. The change trend of the DC internal resistance of the battery cell through the first parameter information can reflect the resistance change of the battery cell due to the leakage of the electrode liquid. As the leakage of the electrolyte in the battery cell in the battery pack continues to increase, the DC internal resistance of the battery cell continues to increase.

[0053] Optionally, the second parameter information is used to indicate the pressure magnitude and / or pressure change trend collected by a pressure sensor arranged in the battery cells of the battery pack.

[0054] The types of pressure sensors arranged in the battery cells in the battery pack may include at least one of the following: a piezoresistive pressure sensor, a capacitive pressure sensor, a piezoelectric pressure sensor, a strain gauge pressure sensor, and a thin film pressure sensor.

[0055] The pressure data collected by the pressure sensor directly reflects the strength of the force exerted by the leaked electrolyte in the battery cell on the sensor surface at at least one moment. When there is no electrolyte leakage in the battery cell in the battery pack, the pressure sensor will not sense the pressure. However, if there is leakage in the battery cell, the leaked electrolyte in the battery cell will spread on the surface of the battery cell. Once it spreads to the surface of the pressure sensor, the pressure detected by the pressure sensor will change significantly due to its own gravity and the impact force generated during the flow.

[0056] The pressure change trend of the pressure sensor arranged in the battery cell of the battery pack reflects the dynamic change of the pressure collected by the pressure sensor over time after the leaked electrolyte in the battery cell continuously flows to the surface of the pressure sensor within a time span. Through continuous monitoring and in-depth analysis of the pressure change trend, it is possible to gain insight into the changes in the amount of electrolyte leakage generated by the battery cells of the battery pack. For example, if the pressure change trend feedback by the pressure sensor shows a slow but continuous upward trend during the continuous charge and discharge cycle of the battery cell, it indicates that electrolyte leakage is gradually generated inside the battery cell, and the leakage amount is increasing. This change in the pressure change trend can reflect the performance change of the battery cell. If the pressure change trend feedback by the pressure sensor does not show an upward trend during the continuous charge and discharge cycle of the battery cell, it means that the battery cell of the battery pack has leaked but the amount of electrolyte leakage has not continued to increase.

[0057] S130. According to the first parameter information and the second parameter information, perform a leakage detection on the battery cells in the battery pack.

[0058] The internal resistance data of the battery cell contains the health status information of the battery cell. When the battery cell is working normally, the internal chemical reactions in the battery cell achieve the storage and release of electrical energy in an orderly manner, and at this time, the internal resistance of the battery cell will maintain within a relatively stable internal resistance range. When the battery cell leaks liquid, the internal chemical environment of the battery cell is damaged, and the loss of the electrolyte will cause the ion conduction path to be blocked, resulting in a decrease in ion conductivity, and thus causing a significant increase in the internal resistance of the battery cell. By continuously monitoring and accurately collecting the internal resistance data of the battery cell, once an abnormal increase in the internal resistance is detected, it is used as a warning signal for the battery cell to leak liquid.

[0059] At the same time, the pressure sensors arranged on the surface of the battery cell also play an indispensable role in the leakage detection of the battery cell. In the design layout of the battery pack, the pressure sensors are arranged on the surface of the battery cell to continuously sense whether there is a pressure change on the surface of the pressure sensor. Since the electrolyte has a certain mass and fluidity, when the battery cell leaks liquid, the leaked electrolyte will flow and spread on the surface of the battery cells in the battery pack. When the electrolyte contacts the surface of the pressure sensor, it will exert a pressure on the sensor. This pressure source includes the gravity of the electrolyte itself and the impact force generated during its flow. The pressure sensor adopts a highly sensitive pressure sensing technology, which can accurately convert these pressure changes into electrical signal outputs. For example, when there is no electrolyte leakage, the electrical signal output by the pressure sensor corresponds to a stable base value, and once there is electrolyte contact and pressure is generated, the intensity of the output electrical signal will change accordingly. By detecting the change of this electrical signal, the pressure information generated by the leaked electrolyte of the battery cell on the surface of the pressure sensor can be accurately obtained. By integrating the first parameter information and the second parameter information, that is, the internal resistance data of the battery cell and the pressure information detected by the pressure sensor, a comprehensive and reliable leakage detection of the battery cells in the battery pack can be performed.

[0060] When the internal resistance data of one of the battery cells in the battery pack shows an abnormal increase, and at the same time the corresponding pressure sensor detects that the pressure has risen significantly and exceeds the normal fluctuation range, it will be determined that the battery cell is very likely to have a leakage phenomenon according to the preset rules and thresholds. After detecting that a battery cell in the battery pack has a leakage phenomenon, immediately trigger the execution of at least one of the following battery processing operations on the battery pack, so as to maximize the safety and stable operation of the battery pack, extend the service life of the battery pack, and reduce the occurrence probability of equipment failures and safety accidents that may be caused by the leakage of the battery cell. Among them, the above at least one battery processing operation includes sending an alarm to notify relevant operation and maintenance personnel, adjusting the operation strategy of the battery pack and suspending the charging and discharging operations of the battery module where the battery cell is located, and starting the cooling system associated with the battery pack to suppress the potential risks caused by the leakage of the electrolyte in the battery cell.

[0061] Optionally, the battery pack is associated with a chip corresponding to the battery management system board. The pressure sensor is connected to the acquisition board and then connected to the battery management system board, for transmitting the pressure data collected by the pressure sensor to the chip corresponding to the battery management system board for arithmetic processing.

[0062] As the energy storage and output unit of the entire energy storage system, the battery pack integrates numerous battery cells inside. These battery cells work together to provide stable and reliable electrical energy for external devices. The battery pack is associated with a chip corresponding to the battery management system board, which undertakes many key functions such as data processing, instruction decision-making, and system coordination. As a detection component extremely sensitive to pressure changes, the pressure sensor is deployed at key positions on the surface of the battery cells inside the battery pack, for capturing in real time the pressure changes caused by the leaked electrolyte of the battery cells on the surface of the pressure sensor.

[0063] To achieve the effective transmission and subsequent processing of the data collected by the pressure sensor, the pressure sensor is first connected to the acquisition board. The acquisition board is a hardware module dedicated to front-end data acquisition and preprocessing, with multiple data acquisition channels, capable of efficiently and accurately acquiring the electrical signals output by multiple pressure sensors simultaneously. During the acquisition process, the acquisition board will perform preliminary conditioning on these raw electrical signals, such as signal amplification, amplifying the weak pressure electrical signals to an amplitude range suitable for subsequent transmission and processing; signal filtering, removing various types of noise interference mixed in the electrical signals during transmission to ensure the accuracy and stability of the data. The pressure data preprocessed by the acquisition board is connected to the battery management system board through specific electrical connection lines. After the connection is completed, the preprocessed pressure data can be smoothly transmitted to the chip corresponding to the battery management system board. The chip integrates complex and powerful arithmetic logic circuits and algorithm programs configured for the battery management system, for performing leakage detection on the battery cells in the battery pack according to the first parameter information and the second parameter information.

[0064] The technical solution of the embodiment of the present invention can directly sense the pressure change generated by the leakage of the electrolyte to the surface of the pressure sensor through the pressure sensor of the battery cells in the battery pack. The pressure sensor is sensitive to the pressure generated by the electrolyte on its surface. Even a small amount of electrolyte leakage may cause the response of the pressure sensor; combined with the ability to obtain the internal resistance data of the battery cells in the battery pack, which can reflect the internal state of the battery cells, it can improve the detection ability of trace liquid leakage, can quickly sense and analyze and judge when the electrolyte leaks. Once an abnormality is detected, it can quickly respond to the electrolyte leakage situation, more accurately determine which specific battery cell has leaked liquid, and achieve precise positioning. At the same time, due to the combination of two different types of parameter information and the detection and analysis from two perspectives of the internal state of the battery cells and the external pressure change, the different parameter information can corroborate and complement each other, reducing the possibility of misjudgment caused by special circumstances or interference of a single parameter, improving the accuracy and reliability of the detection result, being able to reduce the influence of the environmental state on the detection result, and improving the accuracy and reliability of the battery cell liquid leakage detection.

[0065] Figure 2 FIG. is a schematic flow chart of another battery pack liquid leakage detection method provided by the embodiment of the present invention. The technical solution of this embodiment further optimizes the process of determining the first parameter information of the battery cells in the battery pack based on the technical solution of the foregoing embodiment. This embodiment can be combined with each optional solution in one or more of the foregoing embodiments.

[0066] As Figure 2 shown, the battery pack liquid leakage detection method of this embodiment may include the following processes:

[0067] S210. Determine the first circuit physical quantity of the battery pack. The circuit physical quantity includes the voltage and current of the battery cells in the battery pack. The first circuit physical quantity indicates the measured value of the circuit physical quantity of the battery cells in the battery pack at the first moment. The first moment is the moment before the battery pack performs the first operation. The first operation is that the battery pack performs a discharge operation or the battery pack performs a charge operation.

[0068] The first moment may refer to the instant moment before the battery pack performs the first operation. The voltage and current values of the battery cells measured at the first moment can be used as a reference for the initial state of the battery pack before the upcoming charge or discharge operation. The first operation may refer to two basic working modes of the battery pack, namely, the discharge operation or the charge operation. The discharge operation is a process in which the battery pack converts the stored chemical energy into electrical energy and outputs it externally to supply power to external devices; the charge operation is a process in which the battery pack obtains electrical energy from an external power source and converts it into chemical energy and stores it in the battery cells.

[0069] The voltage and current values measured by the battery pack included in the first circuit physical quantity before discharging are respectively the values obtained by detecting the cell terminal voltage and the current in the circuit of the battery pack before the battery pack is about to perform a charging or discharging operation. Among them, the voltage measurement value can reflect the ability of the chemical energy inside the cells in the battery pack to be converted into electrical energy before the battery pack is about to perform a charging or discharging operation. The current measurement value can be the current in the cell circuit when the battery pack is in a static state before the battery pack is about to perform a charging or discharging operation. Current refers to the amount of electric charge passing through the cross-section of the cell per unit time, which reflects the rate of electrical energy transmission.

[0070] S220. Determine the second circuit physical quantity of the battery pack. The second circuit physical quantity indicates the circuit physical quantity measurement values of the cells in the battery pack at at least one second moment, and the second moment is the moment after the battery pack performs the first operation.

[0071] At least one second moment can refer to one or more time points after the battery pack completes the first operation (discharging or charging). The second moment is the moment after the battery pack performs the first operation. Selecting multiple second moments helps to more comprehensively observe the state evolution of the cells after the operation, because the voltage and current of the cells do not stabilize instantaneously after the operation ends, but will experience a period of dynamic change. The second circuit physical quantity can be used to describe the voltage and current of the cells in the battery pack at one or more time points after the battery pack completes the first operation.

[0072] For a charging or discharging battery pack, set multiple second moments at different time intervals after the battery pack finishes the first operation. For a battery pack with a relatively slow charging or discharging process and a stable state change, the time interval between adjacent second moments among the multiple second moments can be appropriately increased.

[0073] By comparing the second circuit physical quantities at different second moments and comparing them with the circuit physical quantity at the first moment, it is possible to clearly understand the change trend of the voltage and current states of the cells after the first operation, such as the voltage recovery speed, current decay situation, etc., so as to evaluate the performance stability, charge and discharge efficiency of the cells in the battery pack, and whether there are potential failure risks, etc.

[0074] S230. Determine the first parameter information of the cells in the battery pack according to the first circuit physical quantity and the second circuit physical quantity. The first parameter information is used to indicate the internal resistance data of the cells in the battery pack, and there are several cells configured in the battery pack.

[0075] Optionally, determine the first parameter information of the battery cells in the battery pack according to the first circuit physical quantity and the second circuit physical quantity, including: determining the first change quantity and the second change quantity according to the first circuit physical quantity and the second circuit physical quantity, where the first change quantity is the voltage change quantity between the voltage of the battery cell at the second moment in the second circuit physical quantity and the voltage of the battery cell indicated in the first circuit physical quantity at the first moment, and the second change quantity is the current change quantity between the current of the battery cell at the second moment in the second circuit physical quantity and the current of the battery cell indicated in the first circuit physical quantity at the first moment. Then, determine the magnitude of the DC internal resistance of the battery cell indicated by the first parameter information according to the ratio of the first change quantity and the second change quantity, and determine the change trend of the DC internal resistance of the battery cell indicated by the first parameter information according to the ratio of the first change quantity and the second change quantity at different second moments.

[0076] Obtain the voltage and current of the battery cells in the battery pack at the first moment, and record them as the first circuit physical quantity. At least one second moment after the first operation of the battery pack, measure and record the voltage and current of the battery cells at different second moments again to obtain the second circuit physical quantity. For example, at the first moment corresponding to before the charging operation, the voltage of the battery cell is 3.7V and the current is 0A; at the second moment after the charging operation ends, the voltage of the battery cell is 4.1V and the current is 0.1A.

[0077] According to Ohm's law and the related theory of battery internal resistance, use the first circuit physical quantity and the second circuit physical quantity to calculate the internal resistance data of the battery cell. A common method is to estimate the internal resistance using the voltage difference and current difference at different moments. Define the voltage of the battery cell at the first moment as V1 and the current as I1, and the voltage at the second moment as V2 and the current as I2. For a simple DC circuit situation, the internal resistance R of the battery cell can be approximately calculated as R = (V2 - V1) / (I2 - I1). However, in practical applications, due to the complex electrochemical process inside the battery, more complex algorithms and models may be required to accurately calculate the internal resistance, such as considering the polarization effect of the battery and the internal resistance characteristics under different SOC (state of charge).

[0078] S240. Determine the second parameter information of the battery cells in the battery pack. The second parameter information is used to indicate the pressure data collected by the pressure sensors arranged on the battery cells in the battery pack. The pressure sensors are used to respond to the pressure generated by the leaked electrolyte on the surface of the pressure sensors in the battery cells.

[0079] As an optional but non-limiting implementation, the pressure sensors arranged on the battery cells in the battery pack are arranged in a first area on the surface of the battery cells in the battery pack. The possibility that the electrolyte leaked from the battery cells in the battery pack flows to the first area is greater than a first preset value, and the possibility that the electrolyte leaked from the battery cells in the battery pack flows to a second area is less than a second preset value. The first preset value is not less than the second preset value. Both the first area and the second area are position areas on the surface of the battery cells in the battery pack; the pressure sensor is configured to respond to the pressure generated by the electrolyte flowing to the first area on the surface of the battery cells in the battery pack when the electrolyte in the battery cells of the battery pack leaks.

[0080] The first area can be the position area where the pressure sensor is arranged on the surface of the battery cells in the battery pack. The first area is not randomly selected but determined through prior analysis. Because in the case of electrolyte leakage from the battery cells, through research and practice, it is found that the possibility that the electrolyte leaked from the battery cells flows to the first area is greater than the first preset value. The first preset value is a probability value comprehensively determined according to factors such as the structural characteristics of the battery cells, the distribution of the electrolyte inside the battery cells, and the leakage path of the electrolyte. For example, due to the relatively weak sealing structure of the battery cells on one side, or under the influence of gravity and the internal pressure distribution of the electrolyte inside the battery cells, the electrolyte is more likely to flow to a position area on the surface of the battery cells. Therefore, pressure sensors can be deployed to sense the pressure generated by the leaked electrolyte.

[0081] The second area is a position area opposite to the first area, and the position of the second area on the surface of the battery cells is different from that of the first area. In the same scenario of battery cell leakage, the possibility that the electrolyte leaked from the battery cells flows to the second area is less than the second preset value. The second preset value is also a probability value comprehensively determined according to factors such as the structural characteristics of the battery cells, the distribution of the electrolyte inside the battery cells, and the possible leakage path of the electrolyte. It is clear that the first preset value is not less than the second preset value, which means that compared with the first area, the probability of the electrolyte flowing to the second area is much lower. Therefore, no pressure sensor for detecting leakage is arranged in the second area.

[0082] When the battery cells show a leakage condition, the leaked electrolyte will flow on the surface of the battery cells. Since the first area is the area where the electrolyte is likely to flow, when the electrolyte flows to the first area on the surface of the battery cells in the battery pack, it will generate pressure on the pressure sensor arranged in the first area. The pressure sensor uses special sensing technology and can keenly sense this pressure change and convert it into an electrical signal for output. For example, in a common piezoresistive pressure sensor, when it is subjected to the pressure of the electrolyte, the resistance value inside it will change. By measuring the change in the resistance value, the magnitude of the pressure can be known, and then it can be determined whether there is electrolyte leakage to the first area. In this way, through the monitoring and analysis of the signals output by the pressure sensor, the effective detection of whether the battery cells have leaked can be realized.

[0083] As an optional but non-limiting implementation solution, the pressure sensor disposed on the battery cells in the battery pack is a thin-film pressure sensor. The thin-film pressure sensor is disposed in the first region of the battery cells in the battery pack. The possibility that the electrolyte leaked from the battery cells in the battery pack flows to the first position region is greater than the possibility that the electrolyte leaked from the battery cells in the battery pack flows to the second position region. Different types of battery cells have different common liquid leakage parts, so the positions of the disposed pressure sensors are also different.

[0084] When the electrolyte leaked from the battery cells flows onto the surface of the thin-film pressure sensor, the thin-film pressure sensor can sense the external pressure generated by the electrolyte located on the surface of the pressure sensor on the surface of the pressure sensor. Even for a very small liquid droplet, it will generate a certain impact force. The thin-film pressure sensor can accurately detect this tiny pressure change, convert the detected pressure into a corresponding digital or analog signal to quantify the pressure magnitude generated by the liquid droplet of the electrolyte.

[0085] As an optional but non-limiting implementation solution, the pressure sensor disposed on the battery cells in the battery pack is a thin-film pressure sensor. The first region on the surface of the battery cells in the battery pack includes at least one of the following configurations: when the battery cells in the battery pack are soft-pack battery cells, the first region on the surface of the battery cells in the battery pack is the region on the surface of the soft-pack battery cells close to the sealing side of the soft-pack battery cells; when the battery cells in the battery pack are cylindrical battery cells, the first region on the surface of the battery cells in the battery pack is the region on the surface of the cylindrical battery cells close to the cap sealing ring and the cap welding part of the cylindrical battery cells; when the battery cells in the battery pack are square battery cells, the first region on the surface of the battery cells in the battery pack is the region on the surface of the square battery cells close to the cover plate welding edge position and the pole position on the cover plate of the square battery cells.

[0086] The sealing of the soft-pack battery cells is a key process in the production process. Its purpose is to ensure the sealing of the battery cells, prevent the leakage of the electrolyte and the entry of external air, moisture and other impurities, so as to ensure the performance and safety of the battery cells. The commonly used materials for sealing the soft-pack battery cells generally consist of an outer polyester film, a middle aluminum foil layer and an inner heat-sealing layer. The polyester film provides mechanical strength and insulation performance, the aluminum foil layer plays a role in blocking oxygen and water vapor, and the heat-sealing layer is hermetically combined with the battery cell body by heating and pressurization during sealing.

[0087] Taking a pouch cell as an example, the structural characteristics of the pouch cell determine that the sealing part is the area most prone to liquid leakage problems. During the manufacturing process of the pouch cell, although the sealing process is strictly controlled, during long-term use, affected by factors such as internal pressure changes generated by charge and discharge, environmental temperature fluctuations, and mechanical vibrations, the sealing performance of the sealing part may gradually decline. Once the sealing of the pouch cell fails, the electrolyte inside the cell will seep out from here and flow along the surface of the cell. Therefore, the pouch cell is prone to electrolyte leakage at the sealing part of the pouch, and the electrolyte will flow onto the surface of the cell. The thin-film pressure sensor is arranged in the area on the surface of the cell close to the sealing side of the pouch cell. With its characteristics of being thin, flexible, and highly sensitive, the thin-film pressure sensor can closely adhere to the surface of the cell. When electrolyte flows to the position where the sensor is located and generates pressure, the pressure sensor can quickly sense it and convert the pressure change into an electrical signal output, thereby promptly sending a liquid leakage alarm to the battery management system.

[0088] The cap sealing ring of the cylindrical cell is used to ensure the sealing of the cylindrical cell, prevent electrolyte leakage, and at the same time prevent external air, moisture, etc. from entering the cell interior, avoiding the adverse effects of these impurities on the cell performance, such as preventing oxidation, hydrolysis and other reactions inside the cell, thereby prolonging the service life of the cell and ensuring its safety. The cap sealing ring of the cylindrical cell is usually of a ring structure and has certain elasticity and toughness. The cap sealing ring of the cylindrical cell can be made of materials resistant to chemical corrosion, high temperature, and aging, such as fluororubber, silicone rubber, etc. These materials can maintain stable performance under the working environment of the cell and ensure the sealing effect of the sealing ring. The cap welding part of the cylindrical cell can use laser welding.

[0089] The liquid leakage situation of the cylindrical cell is different from that of the pouch cell. The cap part of the cylindrical cell is its weak link. As the usage time increases, the sealing ring of the cap may lose its elasticity due to aging, resulting in poor sealing performance; or the cap welding part is prone to corrosion due to being in a complex electrochemical environment for a long time, which may lead to liquid leakage. When liquid leakage occurs, the electrolyte will spread along the surface of the cap. Based on this liquid leakage characteristic of the cylindrical cell, the thin-film pressure sensor can be cleverly arranged on the surface of the cap. When the sealing ring of the cap of the cylindrical cell ages or the cap welding part corrodes and leaks liquid, the electrolyte of the cell will flow to the surface of the cap. Therefore, the thin-film pressure sensor is arranged on the surface of the cap of the cylindrical cell. In this way, as long as electrolyte leaks onto the cap, the thin-film pressure sensor can quickly sense the pressure change and immediately transmit the liquid leakage information.

[0090] Prismatic cells also have their specific positions prone to liquid leakage, mainly concentrated at the welding edges of the cover plate and the terminal posts on the cover plate. During the production and use of prismatic cells, cracks may occur at the welding edges of the cover plate due to welding process defects or long-term mechanical stress, and electrolyte leakage may also occur at the terminal posts due to poor sealing. Considering that prismatic cells are prone to liquid leakage at the welding edges of the cover plate and the terminal posts on the cover plate, a thin-film pressure sensor is selected to be arranged on the cover plate. Through reasonable layout and installation, the pressure sensor can effectively monitor the pressure change generated by the electrolyte leaking from the welding edge or the terminal post and flowing onto the cover plate, ensuring the detection of the liquid leakage problem of prismatic cells in the first time and providing reliable guarantee for the stable operation of the battery pack.

[0091] Exemplarily, referring to Figure 3 , taking a prismatic cell as an example, before assembling the prismatic cell, a thin-film pressure sensor with the same size as the cover plate is pasted on the cover plate of the prismatic cell. The specific pasting method can be referred to Figure 3 . The hollowed-out area corresponding to the terminal post is not pasted with the thin-film pressure sensor. The pressure sensing wire is connected to the acquisition board and then connected to the battery management system board. It is convenient to conduct the acquired pressure signal to the chip of the battery management system board for operation and processing. Under normal circumstances, the pressure value on the thin-film pressure sensor is close to 0. When the pressure value of the thin-film pressure sensor of one of the cells increases, the pressure signal is conducted to the battery management system, and the battery management system makes a determination by integrating the current internal resistance value.

[0092] S250. Detect the liquid leakage of the cells in the battery pack according to the first parameter information and the second parameter information.

[0093] The technical solution of the embodiment of the present invention can directly sense the pressure change generated by the electrolyte leakage to the surface of the pressure sensor through the pressure sensor of the cells in the battery pack. The pressure sensor is sensitive to the pressure generated by the electrolyte on its surface. Even a small amount of electrolyte leakage may cause the response of the pressure sensor; combined with obtaining the internal resistance data of the cells that can reflect the internal state of the cells in the battery pack can improve the detection ability of small amount of liquid leakage, can quickly sense and analyze and judge when the electrolyte leaks, and once an abnormality is detected, quickly detect the electrolyte leakage situation and respond in time, more accurately determine which specific cell has leaked liquid, and achieve accurate positioning. At the same time, due to combining two different types of parameter information, detecting and analyzing from two angles of the internal state of the cells and the external pressure change, different parameter information can be mutually confirmed and supplemented, reducing the possibility of misjudgment caused by special circumstances or interference of a single parameter, improving the accuracy and credibility of the detection result, being able to reduce the influence of the environmental state on the detection result, and improving the accuracy and reliability of the cell liquid leakage detection.

[0094] Figure 4It is a schematic flowchart of another battery pack leakage detection method provided by an embodiment of the present invention. The technical solution of this embodiment further optimizes the process of detecting the leakage of the battery cells in the battery pack according to the first parameter information and the second parameter information on the basis of the technical solution of the foregoing embodiment. This embodiment can be combined with various optional solutions in one or more of the above embodiments.

[0095] As Figure 4 shown, the battery pack leakage detection method of this embodiment may include the following processes:

[0096] S410. Determine the first parameter information of the battery cells in the battery pack. The first parameter information is used to indicate the internal resistance data of the battery cells in the battery pack, and several battery cells are configured in the battery pack.

[0097] S420. Determine the second parameter information of the battery cells in the battery pack. The second parameter information is used to indicate the pressure data collected by the pressure sensors arranged on the battery cells. The pressure sensors are used to respond to the pressure generated by the leaked electrolyte on the surface of the pressure sensors in the battery cells.

[0098] S430. Determine the first detection result of the battery cells in the battery pack according to the first parameter information. The first detection result is used to indicate whether the battery cells in the battery pack meet the first condition. The first condition is used to indicate that the DC internal resistance characteristics of the battery cells in the battery pack present the DC internal resistance characteristics of the leaking battery cells.

[0099] The first parameter information is used to indicate the DC internal resistance data of the battery cells in the battery pack, including the magnitude of the DC internal resistance and the change trend of the DC internal resistance in the battery cells. When the battery cells are working normally, the DC internal resistance of the battery cells is within a relatively stable range, and its value can be determined by the electrolyte characteristics inside the battery cells. By deeply analyzing the first parameter information to determine whether the battery cells meet the first condition, the DC internal resistance characteristics of the battery cells, such as whether the internal resistance value exceeds the normal range and whether the change trend rises abnormally, can be compared with the known DC internal resistance characteristics of the leaking battery cells indicated by the first condition. Due to reasons such as electrolyte loss and change of the internal chemical environment in the known leaking battery cells, the DC internal resistance usually increases significantly and may show a continuous upward trend. If the DC internal resistance characteristics of the battery cells are consistent with the DC internal resistance characteristics of the leaking battery cells, then the first detection result indicates that the battery cells meet the first condition, that is, the battery cells may have leaked; otherwise, it is considered that the battery cells do not meet the first condition and are in a normal state.

[0100] S440. Determine the second detection result of the battery cells in the battery pack according to the second parameter information. The second detection result is used to indicate whether the battery cells in the battery pack meet the second condition. The second condition is used to indicate that the pressure characteristics sensed by the pressure sensors arranged on the battery cells in the battery pack present the pressure characteristics sensed by the pressure sensors arranged on the leaking battery cells.

[0101] The second parameter information is used to indicate the pressure size and pressure change trend collected by the pressure sensor arranged in the battery cell of the battery pack. The pressure sensor is arranged in the area on the surface of the battery cell that is susceptible to leakage. When the battery cell is normal, the pressure sensed by the pressure sensor is in a stable pressure value range and is only affected by slight environmental factors when the battery cell in the battery pack is operating normally. To determine whether the battery cell meets the second condition through the second parameter information, it is necessary to compare the pressure characteristics sensed by the pressure sensor arranged in the battery cell, such as whether the pressure value suddenly increases, whether the pressure change trend shows abnormal fluctuations, etc., with the pressure characteristics sensed by the pressure sensor arranged in the known leaking battery cell. Once the battery cell leaks, the leaked electrolyte will flow on the surface of the battery cell and act on the pressure sensor, causing the pressure sensed by it to increase significantly and change abnormally. If the pressure characteristics of the battery cell pressure sensor are consistent with the pressure characteristics of the leaking battery cell, the second detection result shows that the battery cell meets the second condition, which means that the battery cell is likely to leak; otherwise, it is determined that the battery cell does not meet the second condition, the battery cell in the battery pack is in a normal state, and no electrolyte leakage occurs.

[0102] By detecting whether the battery cell is leaking from two different dimensions, namely, DC internal resistance and pressure change, the two detection methods confirm and complement each other. When one of the detection methods is misjudged due to some special circumstances (such as interference from short-term current fluctuations during DC internal resistance detection), the other detection method can provide a basis for judgment from different perspectives, thereby effectively reducing the misjudgment that may be caused by a single detection method, greatly improving the accuracy of the battery cell leakage detection results, and more reliably ensuring the safe operation of the battery pack. In addition, it can keenly capture subtle changes in the early stages of battery cell leakage. For example, when the battery cell just starts to leak slightly, the DC internal resistance may have begun to rise slowly, and the pressure sensor may also sense extremely small pressure changes. It can be discovered in time when the leakage problem is still in the initial stage, buying enough time to take maintenance measures.

[0103] As an optional but non-limiting implementation scheme, the first condition includes at least one of the following: the DC internal resistance of the battery cells in the battery pack is greater than the reference internal resistance and the DC internal resistance of the battery cells in the battery pack tends to increase over time, and there is a correlation between the reference internal resistance and the charge state and aging state of the battery cells in the battery pack.

[0104] The pressure change trend collected by the pressure sensor refers to the dynamic trend of the pressure values detected by the pressure sensor over a period of time. The aging state of the battery cell is used to describe the state in which the performance of the battery cell gradually deteriorates due to various physical and chemical processes during use or after a certain period of time, including various manifestations such as capacity attenuation, increased internal resistance, and reduced charge and discharge efficiency. The reference internal resistance is positively correlated with the state of charge of the battery cells in the battery pack, and the reference internal resistance increases as the state of charge of the battery cells in the battery pack increases. The reference internal resistance is positively correlated with the aging state of the battery cells in the battery pack, and the reference internal resistance increases as the aging state of the battery cells in the battery pack increases.

[0105] Exemplarily, the battery management system stores a matrix R' of the 10s charging internal resistance values of the battery cells in different states of charge SOC and different aging states, as shown in Table 1. When the battery pack is in use, it will be charged and discharged. When charging the battery pack, the internal resistance value during charging is calculated by collecting the voltage and current values of the battery cells. For example, for the calculation of the charging internal resistance value in the 10% SOC state, the static voltage before charging is 3.21V and the current is 0A; the voltage value after charging for 10s is 3.25V and the current is 20A. Then the internal resistance value R at the current state of 10% SOC = (3.25 - 3.21) / 20 * 1000 = 2mΩ. The battery management system compares the collected internal resistance value with the internal resistance value under the preset aging state. The internal resistance value under the preset aging state is 1.8mΩ, and the actual internal resistance value is larger than the preset internal resistance value. Table 1 shows the internal resistance values of the battery cells in different aging states and different states of charge SOC.

[0106]

[0107] As an optional but non-limiting implementation solution, the second condition includes at least one of the following: the pressure sensor arranged on the battery cells in the battery pack senses pressure, the pressure sensed by the pressure sensor arranged on the battery cells in the battery pack is greater than the reference pressure, the pressure sensed by the pressure sensor arranged on the battery cells in the battery pack shows an increasing trend over time. The reference pressure is the minimum pressure that the pressure sensor can sense the pressure generated by the electrolyte or the pressure generated on the surface of the pressure sensor when the leaked electrolyte in the battery pack meets the reference leakage condition. The reference leakage condition is that the negative effect of the leaked electrolyte in the battery pack on the performance of the battery cells during the charging or discharging process of the battery pack is greater than the preset value.

[0108] Once the battery cell leaks, the leaked electrolyte will flow on the surface and around the battery cell. The electrolyte has a certain mass and fluidity. When the leaked electrolyte contacts the surface of the pressure sensor, it will exert an additional pressure on the sensor. The pressure sensor uses specific sensitive elements and conversion mechanisms to convert this pressure change into an electrical signal output.

[0109] There are two ways to define the reference pressure. The reference pressure can be the minimum pressure that the pressure sensor can sense the pressure generated by the electrolyte, which is determined based on the sensitivity characteristics of the pressure sensor itself. When the external pressure change is less than this minimum value, the pressure sensor may not be able to accurately sense the pressure change, or the change in the electrical signal it outputs is within the noise range and cannot be effectively recognized as the pressure from the electrolyte. The reference pressure can also be the pressure generated on the surface of the pressure sensor when the electrolyte leaked from the battery cells in the battery pack meets the reference leakage condition. Here, the reference leakage condition means that the electrolyte leaked from the battery cells has a negative effect on the performance of the battery cells during the charging or discharging process of the battery pack that is greater than the preset value. For example, when the amount of electrolyte leakage reaches a certain level, it will affect the ion conduction inside the battery cells, resulting in performance problems such as a decrease in the charging and discharging efficiency of the battery cells and an increase in the internal resistance. At this time, the pressure generated on the surface of the pressure sensor is the reference pressure.

[0110] Comparing the pressure actually sensed by the pressure sensor with the reference pressure can determine whether the current pressure change is caused by the leakage of the electrolyte with an actual impact. If the sensed pressure is greater than the reference pressure, it is very likely that the battery cell has suffered relatively serious leakage, which has posed a potential threat to the battery performance. Continuously track the change of the pressure sensed by the pressure sensors arranged on the battery cells in the battery pack over time. By recording the pressure values output by the pressure sensors at different time points, a curve of pressure change over time is formed. Under normal circumstances, the pressure value should remain relatively stable. Even if there are minor fluctuations, they are within an acceptable range. When the pressure shows an increasing trend, this is an important abnormal signal. Because if it is only a short-term and accidental pressure fluctuation, it may be caused by other interference factors, such as instantaneous air flow changes inside the battery pack, etc. However, a continuous increasing trend of pressure indicates that there may be continuous electrolyte leakage or the leaked electrolyte is accumulating continuously, and the effect on the pressure sensor is continuously enhanced.

[0111] By clarifying a series of steps such as the pressure sensor sensing pressure, comparing with the reference pressure, and monitoring the pressure change trend, a comprehensive and accurate battery cell leakage detection system is constructed. Compared with relying only on a single pressure threshold for judgment, considering multiple factors comprehensively can more accurately identify whether the battery cell has leaked and the severity of the leakage, reduce potential safety hazards caused by misjudgment or missed judgment, and determine the reference pressure with the negative effect on the battery cell performance as the reference leakage condition, so that the detection system can issue a warning before the leakage of the battery cell has a substantial adverse impact on the battery cell performance, which helps the operation and maintenance personnel to discover potential problems in time and take maintenance measures in advance.

[0112] S450. Perform leakage detection on the battery cells in the battery pack according to the first detection result and the second detection result.

[0113] As an optional but non-limiting implementation scheme, according to the first detection result and the second detection result, a leakage detection is performed on the battery cells in the battery pack, including but not limited to the following steps:

[0114] When the first test result indicates that the battery cells in the battery pack meet the first condition, and the second test result indicates that the battery cells in the battery pack meet the second condition, it is determined that the battery cells in the battery pack are leaking cells, and the leaking cells are located based on the pressure sensor identifiers arranged on the battery cells in the battery pack; when the first test result indicates that the battery cells in the battery pack do not meet the first condition or the second test result indicates that the battery cells in the battery pack do not meet the second condition, it is determined that the battery cells in the battery pack are not leaking cells, and leakage detection is continuously performed for the battery cells in the battery pack for a preset time period.

[0115] As an optional but non-limiting implementation scheme, before determining the first detection result of the battery cell in the battery pack according to the first parameter information, the following steps are also included but not limited to:

[0116] Determine the degree of aging and the state of charge of the battery cells in the battery pack; determine the reference internal resistance of the battery cells in the battery pack through the battery internal resistance configuration information according to the degree of aging and the state of charge of the battery cells in the battery pack, and the battery internal resistance configuration information is used to record the internal resistance of the battery cells in the battery pack corresponding to different state of charge levels and different degrees of cell aging.

[0117] The cell aging state may refer to the degree to which the cell performance gradually decreases during use due to multiple charge and discharge cycles, long-term storage or other factors. The cell aging state may be manifested as at least one of capacity attenuation, increased internal resistance and reduced charge and discharge efficiency.

[0118] Optionally, determining the degree of aging of the battery cells in the battery pack includes: fully charging and fully discharging the battery cells, measuring the amount of electricity actually discharged from the battery cells and comparing it with the initial rated capacity of the battery cells, and determining the degree of aging of the battery cells by comparing the results. The rated capacity may be the maximum value of the amount of charge that the battery cells can accommodate and store under given standards or ideal conditions (such as set temperature, charging rate, etc.).

[0119] Optionally, determining the aging degree of the battery cell in the battery pack includes: measuring the DC internal resistance or AC internal resistance of the battery cell in real time, and judging the aging degree of the battery cell by using the DC internal resistance or AC internal resistance of the battery cell measured in real time. As the battery cell ages, the internal resistance will gradually increase.

[0120] Optionally, determining the degree of aging of the battery cells in the battery pack includes: performing cyclic voltammetry tests on the battery cells, analyzing the current responses of the battery cells at different potentials, thereby obtaining information about electrode reaction kinetics and changes in electrode material structure, and judging the degree of aging of the battery cells.

[0121] Optionally, determine the aging degree of the battery cells in the battery pack, including: analyzing the composition, concentration change and the presence of decomposition products of the electrolyte in the battery cells, and judging the aging degree of the battery cells by using the electrolyte analysis results. Among them, the change of the electrolyte will affect the performance and life of the battery cells, and the aging condition of the battery cells can be understood by analyzing the electrolyte.

[0122] The internal resistance of the battery cells under different state of charge (SOC) and different aging states can refer to the internal resistance situation of the battery cells in the battery pack when the battery cells are at different remaining power levels and different degrees of performance degradation. The internal resistance of the battery cells under different SOC and different aging states can reflect the performance change law of the battery cells under various use conditions. For example, as the aging degree of the battery cells deepens, at the same SOC, the internal resistance of the battery cells may gradually increase; and under different SOC, even for the battery cells in the same aging state, their internal resistances may also be different, because the internal chemical reactions and ion transport conditions of the battery cells in the battery pack are different under different state of charge, thus affecting the size of the internal resistance.

[0123] The technical solution of the present invention detects the battery cells in the battery pack from two different dimensions of the DC internal resistance characteristics of the battery cells and the pressure characteristics sensed by the pressure sensor respectively. By comprehensively integrating the two parameter information to judge whether the battery cells are leaking liquid, compared with the single-dimensional detection method, it can more comprehensively and accurately reflect the state of the battery cells, improve the reliability and accuracy of the detection. Moreover, the configured first condition and second condition are set respectively for the DC internal resistance characteristics and pressure characteristics of the leaking battery cells, so that the detection result can specifically indicate which battery cells in the battery pack meet the relevant characteristics of leaking liquid, thereby realizing the precise positioning of the leaking battery cells. Through the real-time detection of the battery cells, it can detect the abnormal changes of their DC internal resistance and pressure before the battery cells show signs of leaking liquid but have not caused serious consequences, so as to issue an early warning in advance, reduce the risk of safety accidents that may be caused by the leaking of the battery cells, and improve the stability and safety of the battery pack system.

[0124] Figure 5 The structure diagram of a battery pack leakage detection device is provided for an embodiment of the present invention. This embodiment is applicable to the situation where the battery cells in the battery pack in the energy storage system leak liquid and can be detected in a timely and accurate manner. The battery pack leakage detection device can be implemented in the form of hardware and / or software, and the battery pack leakage detection can be configured in any electronic device with network communication function.

[0125] As Figure 5 shown, the battery pack leakage detection device of this embodiment includes the following:

[0126] The first determination module 510 is configured to determine first parameter information of the battery cells in the battery pack, where the first parameter information is used to indicate the internal resistance data of the battery cells in the battery pack, and a plurality of battery cells are configured in the battery pack;

[0127] The second determination module 520 is configured to determine second parameter information of the battery cells in the battery pack, where the second parameter information is used to indicate the pressure data collected by the pressure sensors disposed on the battery cells in the battery pack, and the pressure sensors are configured to respond to the pressure generated by the leaked electrolyte in the battery cells on the surface of the pressure sensors;

[0128] The detection module 530 is configured to perform leakage detection on the battery cells in the battery pack according to the first parameter information and the second parameter information.

[0129] Based on the above embodiments, optionally, determining the first parameter information of the battery cells in the battery pack includes:

[0130] Determine the first circuit physical quantity of the battery pack, where the circuit physical quantity includes the voltage and current of the battery cells in the battery pack, and the first circuit physical quantity indicates the measured value of the circuit physical quantity of the battery cells in the battery pack at a first moment, and the first moment is the moment before the battery pack performs a first operation, and the first operation is a discharge operation or a charge operation of the battery pack;

[0131] Determine the second circuit physical quantity of the battery pack, where the second circuit physical quantity indicates the measured value of the circuit physical quantity of the battery cells in the battery pack at at least one second moment, and the second moment is the moment after the battery pack performs the first operation;

[0132] Determine the first parameter information of the battery cells in the battery pack according to the first circuit physical quantity and the second circuit physical quantity.

[0133] Based on the above embodiments, optionally, the first parameter information is used to indicate the magnitude of the DC internal resistance of the battery cells in the battery pack and / or the change trend of the DC internal resistance of the battery cells.

[0134] Based on the above embodiments, optionally, the pressure sensors disposed on the battery cells in the battery pack are disposed in a first area on the surface of the battery cells in the battery pack, the possibility that the leaked electrolyte in the battery cells in the battery pack flows to the first area is greater than a first preset value, the possibility that the leaked electrolyte in the battery cells in the battery pack flows to a second area is less than a second preset value, the first preset value is not less than the second preset value, and both the first area and the second area are position areas on the surface of the battery cells in the battery pack; the pressure sensors are configured to respond to the pressure generated by the electrolyte flowing to the first area on the surface of the battery cells in the battery pack in the case of electrolyte leakage in the battery cells of the battery pack.

[0135] Based on the above embodiments, optionally, the pressure sensor disposed on the battery cells in the battery pack is a thin-film pressure sensor, and the first region on the surface of the battery cells in the battery pack includes at least one of the following configurations:

[0136] When the battery cells in the battery pack are soft-pack battery cells, the first region on the surface of the battery cells in the battery pack is the region on the surface of the soft-pack battery cells close to the sealing side of the soft-pack battery cells;

[0137] When the battery cells in the battery pack are cylindrical battery cells, the first region on the surface of the battery cells in the battery pack is the region on the surface of the cylindrical battery cells close to the cap sealing ring and the cap welding part of the cylindrical battery cells;

[0138] When the battery cells in the battery pack are square battery cells, the first region on the surface of the battery cells in the battery pack is the region on the surface of the square battery cells close to the cover plate welding edge position and the pole position on the cover plate of the square battery cells.

[0139] Based on the above embodiments, optionally, the second parameter information is used to indicate the magnitude of the pressure collected by the pressure sensor disposed on the battery cells in the battery pack and / or the pressure change trend.

[0140] Based on the above embodiments, optionally, the battery pack is associated with a chip corresponding to the battery management system board, the pressure sensor is connected to the acquisition board and connected to the battery management system board, and is used to transmit the pressure data collected by the pressure sensor to the chip corresponding to the battery management system board for arithmetic processing.

[0141] Based on the above embodiments, optionally, performing leakage detection on the battery cells in the battery pack according to the first parameter information and the second parameter information includes:

[0142] Determining a first detection result of the battery cells in the battery pack according to the first parameter information, where the first detection result is used to indicate whether the battery cells in the battery pack meet a first condition, and the first condition is used to indicate that the DC internal resistance characteristic of the battery cells in the battery pack presents the DC internal resistance characteristic of the leaking battery cells;

[0143] Determining a second detection result of the battery cells in the battery pack according to the second parameter information, where the second detection result is used to indicate whether the battery cells in the battery pack meet a second condition, and the second condition is used to indicate that the pressure characteristic sensed by the pressure sensor disposed on the battery cells in the battery pack presents the pressure characteristic sensed by the pressure sensor disposed on the leaking battery cells;

[0144] Performing leakage detection on the battery cells in the battery pack according to the first detection result and the second detection result.

[0145] Based on the above embodiments, optionally, the first condition includes at least one of the following: the DC internal resistance of the battery cells in the battery pack is greater than the reference internal resistance, and the DC internal resistance of the battery cells in the battery pack shows an increasing trend over time. The reference internal resistance is related to the state of charge and aging state of the battery cells in the battery pack;

[0146] The second condition includes at least one of the following: the pressure sensor arranged on the battery cells in the battery pack senses pressure, the pressure sensed by the pressure sensor arranged on the battery cells in the battery pack is greater than the reference pressure, the pressure sensed by the pressure sensor arranged on the battery cells in the battery pack shows an increasing trend over time. The reference pressure is the minimum pressure that the pressure sensor can sense the electrolyte to generate, or the pressure generated on the surface of the pressure sensor when the leaked electrolyte in the battery pack in the battery cells meets the reference leakage condition. The reference leakage condition is that the leaked electrolyte in the battery cells in the battery pack has a negative effect on the battery performance during the charging or discharging process of the battery pack greater than a preset value.

[0147] Based on the above embodiments, optionally, according to the first detection result and the second detection result, performing a leakage detection on the battery cells in the battery pack includes:

[0148] When the first detection result indicates that the battery cells in the battery pack meet the first condition, and the second detection result indicates that the battery cells in the battery pack meet the second condition, it is determined that the battery cells in the battery pack are leaking cells, and the leaking cells are located based on the identification of the pressure sensors arranged on the battery cells in the battery pack;

[0149] When the first detection result indicates that the battery cells in the battery pack do not meet the first condition or the second detection result indicates that the battery cells in the battery pack do not meet the second condition, it is determined that the battery cells in the battery pack are not leaking cells, and the leakage detection is continuously performed on the battery cells in the battery pack for a preset duration.

[0150] Based on the above embodiments, optionally, before determining the first detection result of the battery cells in the battery pack according to the first parameter information, further includes:

[0151] Determining the aging degree and state of charge of the battery cells in the battery pack;

[0152] According to the aging degree and state of charge of the battery cells in the battery pack, determining the reference internal resistance of the battery cells in the battery pack through the cell internal resistance configuration information, where the cell internal resistance configuration information is used to record the internal resistance situation of the battery cells in the battery pack corresponding to different state of charge levels and different cell aging degrees of the battery cells in the battery pack.

[0153] In the technical solution of the embodiment of the present invention, the pressure sensor of the battery cell in the battery pack can directly sense the pressure change caused by the leakage of the electrolyte to the surface of the pressure sensor. The pressure sensor is sensitive to the pressure generated by the electrolyte on its surface. Even a small amount of electrolyte leakage may cause the response of the pressure sensor. By combining the internal resistance data of the battery cell that can reflect the internal state of the battery cell in the battery pack, the detection ability for trace liquid leakage can be improved, and it can quickly sense and analyze and judge when the electrolyte leaks. Once an abnormality is detected, the electrolyte leakage situation can be quickly discovered and responded to, and it can more accurately determine which specific battery cell has leaked liquid, realizing accurate positioning. At the same time, because two different types of parameter information are combined and detected and analyzed from two perspectives of the internal state of the battery cell and the external pressure change, the different parameter information can corroborate and supplement each other, reducing the possibility of misjudgment caused by special circumstances or interference of a single parameter, improving the accuracy and credibility of the detection result, being able to reduce the influence of the environmental state on the detection result, and improving the accuracy and reliability of the battery cell liquid leakage detection.

[0154] The battery pack liquid leakage detection device provided in the embodiment of the present invention can execute the battery pack liquid leakage detection method provided in any embodiment of the present invention above, and has the corresponding functions and beneficial effects for executing the battery pack liquid leakage detection method. For the detailed process, refer to the relevant operations of the battery pack liquid leakage detection method in the foregoing embodiments.

[0155] It should be noted that the various units and modules included in the above device are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of the embodiment of the present invention.

[0156] According to the embodiment of the present invention, the process described above with reference to the flowchart can be applied to an energy storage system. For example, an embodiment of the present invention includes an energy storage system, which includes: at least one battery module; at least one battery management system, where the at least one battery management system corresponds to the at least one battery module one by one, the battery management system is electrically connected to the corresponding battery module, and the battery management system is used to include program codes for executing the battery pack liquid leakage detection method shown in the flowchart.

[0157] In such an embodiment, the energy storage system provided in the present application is applicable to a variety of application scenarios, such as the grid-connected power generation energy storage field, the off-grid photovoltaic energy storage field (for supplying power to electrical equipment in homes, RVs, and yachts), the wind power storage generation field, the electric equipment field, etc. It can be specifically determined according to the actual application scenario and is not limited here. Hereinafter, the off-grid photovoltaic energy storage field will be taken as an example for illustration, and the other application scenarios are basically similar and will not be elaborated.

[0158] In an off-grid photovoltaic and energy storage application scenario, a complete photovoltaic and energy storage system typically includes a photovoltaic power generation system, a power conversion system, an energy storage system, and an electrical load system. The photovoltaic power generation system is composed of a number of solar panels connected in series and parallel, and is used to convert solar energy into electrical energy. The power conversion system injects the electrical energy generated by the photovoltaic power generation system into the energy storage system for storage. The electrical load system then adapts the electrical energy stored in the energy storage system to the power required by the electrical load devices. The aforementioned power conversion system can generally be implemented using, for example, a DC / DC converter with MPPT function. The electrical load system can generally be implemented using a DC / DC converter and a DC / AC converter. Here, the energy storage system will be introduced in detail. The energy storage system is usually composed of multiple battery packs connected to each other. Using battery packs in series can increase the output voltage of the battery bank, and using battery packs in parallel can obtain a larger battery capacity. Therefore, in order to obtain an energy storage system with a target voltage level and capacity, users will connect multiple battery packs in series and parallel with each other to obtain a high-voltage and large-capacity energy storage system for energy storage and power supply. In addition, for the convenience of centralized and unified control, each battery pack in the energy storage system is usually also provided with a communication interface, and the battery packs can communicate with each other through means such as CAN bus, RS485 bus, and RS232 bus. Currently, with the further development of the new energy industry and the extension of application scenarios, higher requirements are put forward for the various performances of the energy storage system, including system stability and consistency, waterproof and dustproof performance, and safety level, etc.

[0159] In an optional but non-limiting implementation manner, the solution of the present application further provides a photovoltaic power generation system, where the photovoltaic power generation system includes: a photovoltaic power generation component, a controller, and the energy storage system according to any one of the above embodiments; the photovoltaic power generation component is used to convert solar energy into direct current electrical energy; the controller is used to store the direct current electrical energy in the energy storage system.

[0160] Figure 6 FIG. shows a schematic structural diagram of an electronic device 10 that can be used to implement the embodiments of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described herein and / or claimed.

[0161] As Figure 6As shown, the electronic device 10 includes at least one processor 11 and a memory communicatively connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc. The memory stores a computer program executable by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0162] Multiple components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disc, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0163] The processor 11 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the battery pack leakage detection method.

[0164] Specifically, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a non-transitory computer-readable medium. The computer program contains program codes for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network via the communication unit 19, or installed from the storage unit 18, or installed from the ROM 12. When the computer program is executed by the processor 11, the above functions defined in the method of the embodiment of the present invention are executed.

[0165] In some embodiments, the battery pack leakage detection method can be implemented as a computer program tangibly embodied in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the battery pack leakage detection method described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the battery pack leakage detection method by any other suitable means (e.g., by means of firmware).

[0166] The various embodiments of the systems and techniques described above in this document can be implemented in digital electronic circuitry, integrated circuit systems, field-programmable gate arrays (FPGA), application specific integrated circuits (ASIC), application specific standard products (ASSP), systems-on-chip (SOC), complex programmable logic devices (CPLD), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include: being implemented in one or more computer programs executable and / or interpretable on a programmable system including at least one programmable processor, which can be a special-purpose or general-purpose programmable processor that receives data and instructions from a storage system, at least one input device, and at least one output device, and transmits the data and instructions to the storage system, the at least one input device, and the at least one output device.

[0167] The computer program for implementing the method of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowchart and / or block diagram are implemented. The computer program can be executed entirely on the machine, partially on the machine, as a stand-alone software package partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0168] In the context of the present invention, a computer-readable storage medium can be a tangible medium that can contain or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, the computer-readable storage medium can be a machine-readable signal medium. More specific examples of the machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0169] In order to provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the electronic device. Other kinds of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, speech input, or tactile input).

[0170] The systems and techniques described herein can be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer having a graphical user interface or a web browser through which the user can interact with an implementation of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local area network (LAN), wide area network (WAN), blockchain network, and the Internet.

[0171] A computing system may include a client and a server. The client and the server are generally far from each other and usually interact via a communication network. The client-server relationship is created by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or a cloud host, which is a host product in the cloud computing service system, and solves the defects of difficult management and weak business scalability existing in traditional physical hosts and VPS services.

[0172] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0173] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A battery pack leakage detection method, characterized in that: The method comprises: Determine first parameter information of a battery cell in a battery pack, where the first parameter information is used to indicate internal resistance data of the battery cell in the battery pack, and the battery pack is configured with a plurality of battery cells; Determine second parameter information of a battery cell in a battery pack, where the second parameter information is used to indicate pressure data collected by a pressure sensor arranged on the battery cell in the battery pack, where the pressure sensor is used to respond to pressure generated on a surface of the pressure sensor by electrolyte leaking from the battery cell; Perform leakage detection on the battery cells in the battery pack according to the first parameter information and the second parameter information.

2. The method according to claim 1, characterized in that: Determine the first parameter information of the battery cell in the battery pack, including: Determine a first circuit physical quantity of the battery pack, the circuit physical quantity including a voltage and a current of a battery cell in the battery pack, the first circuit physical quantity indicating a measured value of the circuit physical quantity of the battery cell in the battery pack at a first moment, the first moment being a moment before the battery pack performs a first operation, the first operation being a discharge operation of the battery pack or a charge operation of the battery pack; Determine a second circuit physical quantity of the battery pack, where the second circuit physical quantity indicates a circuit physical quantity measurement value of a cell in the battery pack at at least one second moment, where the second moment is a moment after the battery pack performs a first operation; First parameter information of a battery cell in a battery pack is determined according to the first circuit physical quantity and the second circuit physical quantity.

3. The method according to claim 1, characterized in that The pressure sensor arranged on the battery cell in the battery pack is arranged in a first area on the surface of the battery cell in the battery pack, the possibility that the electrolyte leaked in the battery cell in the battery pack flows to the first area is greater than a first preset value, and the possibility that the electrolyte leaked in the battery cell in the battery pack flows to the second area is less than a second preset value, the first preset value is not less than the second preset value, and the first area and the second area are both position areas on the surface of the battery cell in the battery pack; the pressure sensor is configured to respond to the pressure generated by the electrolyte flowing to the first area on the surface of the battery cell in the battery pack when the electrolyte leaks in the battery cell of the battery pack.

4. The method according to claim 3, characterized in that The pressure sensor arranged on the battery cell in the battery pack is a thin film pressure sensor, and the first area on the surface of the battery cell in the battery pack includes at least one of the following configurations: In the case where the battery cell of the battery pack is a soft-pack battery cell, the first area on the surface of the battery cell in the battery pack is an area on the surface of the soft-pack battery cell close to a sealing side of the soft-pack battery cell; In the case where the battery cell of the battery pack is a cylindrical battery cell, the first area on the surface of the battery cell in the battery pack is an area on the surface of the cylindrical battery cell close to the cap sealing ring and the cap welding part of the cylindrical battery cell; When the battery cell of the battery pack is a square battery cell, the first area on the surface of the battery cell in the battery pack is an area on the surface of the square battery cell close to the welding edge of the cover plate of the square battery cell and one side of the pole position on the cover plate.

5. The method according to claim 1, characterized in that The first parameter information is used to indicate the magnitude of the DC internal resistance of the battery cell in the battery pack and / or the DC internal resistance change trend of the battery cell; the second parameter information is used to indicate the magnitude of the pressure and / or the pressure change trend collected by the pressure sensor arranged in the battery cell in the battery pack.

6. The method according to claim 1, characterized in that The battery pack is associated with a chip corresponding to a battery management system board. The pressure sensor is connected to an acquisition board and is connected to the battery management system board to transmit pressure data collected by the pressure sensor to a chip corresponding to the battery management system board for calculation and processing.

7. The method according to claim 1, characterized in that Performing leakage detection on the battery cells in the battery pack according to the first parameter information and the second parameter information includes: Determine a first detection result of the battery cell in the battery pack according to the first parameter information, the first detection result is used to indicate whether the battery cell in the battery pack meets a first condition, the first condition is used to indicate that the DC internal resistance characteristics of the battery cell in the battery pack present the DC internal resistance characteristics of the leaking battery cell; Determine a second detection result of the battery cell in the battery pack according to the second parameter information, the second detection result is used to indicate whether the battery cell in the battery pack meets a second condition, the second condition is used to indicate that the pressure characteristics sensed by the pressure sensor arranged in the battery cell in the battery pack present the pressure characteristics sensed by the pressure sensor arranged in the leaking battery cell; According to the first detection result and the second detection result, a leakage detection is performed on the battery cells in the battery pack.

8. The method according to claim 7, characterized in that The first condition includes at least one of the following: the DC internal resistance of the battery cell in the battery pack is greater than the reference internal resistance and the DC internal resistance of the battery cell in the battery pack tends to increase over time, and the reference internal resistance is associated with the charge state and aging state of the battery cell in the battery pack; The second condition includes at least one of the following: the pressure sensor arranged in the battery cells of the battery pack senses pressure, the pressure sensed by the pressure sensor arranged in the battery cells of the battery pack is greater than a reference pressure, and the pressure sensed by the pressure sensor arranged in the battery cells of the battery pack tends to increase over time, the reference pressure is the minimum value of the pressure generated by the electrolyte that the pressure sensor can sense, or the pressure generated on the surface of the pressure sensor when the electrolyte leaked from the battery cells of the battery pack meets the reference leakage condition, and the reference leakage condition is that the electrolyte leaked from the battery cells of the battery pack has a negative effect on the battery performance during charging or discharging of the battery pack that is greater than a preset value.

9. The method according to claim 7, characterized in that: According to the first detection result and the second detection result, a leakage detection is performed on the battery cells in the battery pack, including: When the first detection result indicates that the battery cell in the battery pack meets the first condition, and the second detection result indicates that the battery cell in the battery pack meets the second condition, it is determined that the battery cell in the battery pack is a leaking battery cell, and the leaking battery cell is located based on the pressure sensor identifier arranged on the battery cell in the battery pack; When the first detection result indicates that the battery cells in the battery pack do not meet the first condition or the second detection result indicates that the battery cells in the battery pack do not meet the second condition, it is determined that the battery cells in the battery pack are not leaking cells, and leakage detection is performed on the battery cells in the battery pack for a preset time.

10. The method according to claim 8, characterized in that Before determining a first detection result of the battery cell in the battery pack according to the first parameter information, the method further includes: Determining the aging degree and state of charge of the battery cells in the battery pack; According to the aging degree and the state of charge of the battery cells in the battery pack, the reference internal resistance of the battery cells in the battery pack is determined through the battery cell internal resistance configuration information, and the battery cell internal resistance configuration information is used to record the internal resistance of the battery cells in the battery pack corresponding to different state of charge levels and different degrees of aging of the battery cells.

11. A battery pack leakage detection device, characterized in that: The device comprises: A first determination module, used to determine first parameter information of a battery cell in a battery pack, wherein the first parameter information is used to indicate internal resistance data of the battery cell in the battery pack, and the battery pack is configured with a plurality of battery cells; A second determination module is used to determine second parameter information of a battery cell in a battery pack, wherein the second parameter information is used to indicate pressure data collected by a pressure sensor arranged on the battery cell in the battery pack, and the pressure sensor is used to respond to the pressure generated by the electrolyte leaking from the battery cell on the surface of the pressure sensor; A detection module is used to perform leakage detection on the battery cells in the battery pack according to the first parameter information and the second parameter information.

12. An energy storage system, characterized in that: include: At least one battery module; at least one battery management system, the at least one battery management system corresponds one-to-one to the at least one battery module, the battery management system is electrically connected to the corresponding battery module, and the battery management system is used to execute the battery pack leakage detection method described in any one of claims 1-10.

13. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the battery pack leakage detection method according to any one of claims 1 to 10.

14. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the battery pack leakage detection method according to any one of claims 1 to 10 when executed.

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