A lithium ion battery safety management system and method

Abstract

The application belongs to the technical field of lithium batteries, and particularly relates to a lithium ion battery safety management system and method. The system comprises a charger control console and a main control disconnecting module, and further comprises a thermal runaway information acquisition module and / or a battery information storage module. The application sets the main control disconnecting module in the lithium battery charging circuit, so as to lock the lithium battery when it is determined that the lithium battery is a non-original battery or the battery is aging, cut off the possibility of self-ignition caused by recharging, and ensure the safety of the lithium battery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium batteries, and particularly relates to a lithium ion battery safety management system and method. BACKGROUND

[0002] The definition of battery thermal runaway is that, when a battery is charged, the increase of charging current caused by the increase of battery temperature, and the further increase of battery temperature caused by the decomposition of electrolyte are a positive feedback enhancement process, which can cause rapid damage of the battery, and even serious bulging and deformation of the shell. The mechanism of thermal runaway of the storage battery is that the internal chemical electromotive force and the resistance of the electrolyte of all secondary batteries decrease with the increase of temperature, so once the heat generated by the plate accumulates and causes the temperature to rise, the resistance of the storage battery to the charger will decrease, which will further cause the charging current to rise, and more significant thermal effects will be produced. In an actual operating environment, if the new thermal equilibrium temperature exceeds the bearing capacity of the battery structure itself, the storage battery will be damaged in a relatively fast temperature rising process, and in severe cases, internal short circuit and even explosion (lithium battery) may occur due to rupture of the separator.

[0003] However, in the long-term use process, as the most commonly used and relatively mature battery type, the safety performance of the lithium ion battery (hereinafter referred to as lithium battery) needs to be further optimized. In the prior art, a circuit breaking control module is generally provided in the charger, which cooperates with the data detection in the lithium battery to automatically disconnect, but the lithium battery itself does not have a corresponding adjusting and disconnecting device. In the long-term use process of the lithium battery, once the detection data appears certain abnormality, the possibility of overall spontaneous combustion is still high, and as the user is reluctant to replace the battery, when it is found that the battery cannot be normally charged, the user generally chooses to replace the charger without circuit breaking function instead of replacing the lithium battery, so as to more easily increase the fire safety hazard and cause the fire problem. SUMMARY

[0004] The application provides a lithium ion battery safety management system and method, which solves the problem of high safety hazard of the lithium battery caused by the fact that the user generally chooses to replace the charger without circuit breaking function instead of replacing the lithium battery in the prior art.

[0005] To solve the above technical problems, the technical solutions and the beneficial effects corresponding to the technical solutions are as follows:

[0006] The application provides a lithium ion battery safety management system, which comprises a charger control console and a master control disconnecting module, and further comprises a thermal runaway information acquisition module and / or a battery information storage module.

[0007] The master control disconnecting module is an electric control switch, which is used for disconnecting the lithium battery charging circuit under the control of the charger control console.

[0008] The thermal runaway information acquisition module is connected with the charger control console, and is used for acquiring the information related to thermal runaway and sending the information to the charger control console.

[0009] The battery information storage module is connected with the charger control console, and is used for transmitting the stored lithium battery identification code to the charger control console.

[0010] The charger control console is used for judging whether the lithium battery is an original battery according to the lithium battery identification code and / or judging whether the lithium battery is aged according to the information related to thermal runaway, and making the main control disconnecting module act to lock the lithium battery when it is determined that the lithium battery is not an original battery or the lithium battery is aged.

[0011] The technical scheme has the beneficial effects that: the safety management system of the present application is provided with the main control disconnecting module for disconnecting the lithium battery charging circuit, and further includes the thermal runaway information acquisition module and / or the battery information storage module, so that the charger control console can judge the safety of the battery from two aspects, one is whether the battery is an original battery, and the other is whether the battery is aged, and the main control disconnecting module is actively controlled to be disconnected in case of any problem, so as to completely disconnect the charging function and cut off the possibility of self-ignition caused by recharging, thereby ensuring the safety of the lithium battery.

[0012] Further, in order to further ensure the safety of the lithium battery, the safety management system further includes an auxiliary disconnecting module, the auxiliary disconnecting module includes a temperature control switch and / or a fuse, and is arranged on the lithium battery charging circuit.

[0013] Further, in order to obtain environmental temperature information to comprehensively judge whether the lithium battery is aged in combination with the environmental temperature information, the thermal runaway information acquisition module includes an external environmental information acquisition unit, and the external environmental information acquisition unit includes an environmental temperature sensor.

[0014] Further, in order to comprehensively obtain the thermal runaway information of the lithium battery to accurately judge whether the lithium battery is aged, the thermal runaway information acquisition module includes a battery internal information acquisition unit, and the battery internal information acquisition unit includes a CAN information acquisition unit, a battery temperature sensor and a battery voltage sensor; the CAN information acquisition unit is connected with the BMS to obtain the charging and discharging information of the battery from the BMS, and the charging and discharging information includes the charging time length; the battery temperature sensor is used for acquiring the temperature of the battery; and the battery voltage sensor is used for acquiring the voltage of the battery.

[0015] Further, in order to accurately judge whether the lithium battery is aged, the charger control console uses the following method to judge whether the lithium battery is aged:

[0016] According to the charging and discharging information of each time, the total charging time of the lithium battery is determined;

[0017] According to the charging and discharging information of each time, the total charging times of the lithium battery and the number of times of abnormal charging are determined, and the ratio of the number of times of abnormal charging to the total charging times is calculated;

[0018] If the total charging time is greater than the set total time threshold and the ratio is greater than the set ratio threshold, it is determined that the lithium battery has aged.

[0019] Further, the abnormal charging condition includes that the charging time is greater than the set charging time threshold.

[0020] Further, in order to accurately determine whether the lithium battery is an original battery, the battery information storage module includes a first storage unit arranged at the lithium battery and a second storage unit arranged on the vehicle, and the first storage unit and the second storage unit both store the lithium battery identification code; the charger control console determines whether it is an original battery by the following method: if the lithium battery identification code stored in the first storage unit is consistent with the lithium battery identification code stored in the second storage unit, the lithium battery is an original battery.

[0021] Further, in order to share the data processing pressure of the charger controller, the safety management system further includes a lithium battery charging control unit, which is in communication connection with the charger control console and controls the disconnection of the main control module, and is used to receive the control command of the charger control console and execute the control command to control the main control module to act to disconnect the lithium battery charging circuit.

[0022] Further, in order to facilitate and quickly obtain the lithium battery identification code stored in the first storage unit, the first storage unit is arranged in an SD card, the SD card is arranged in the inner cavity of the lithium battery, and the safety management system further includes an SD card data reader for reading the lithium battery identification code stored in the first storage unit, and is connected with the charger control console to transmit the read lithium battery identification code to the charger control console.

[0023] The application also provides a lithium ion battery safety management method, which comprises the following steps:

[0024] Obtaining the lithium battery identification code to determine whether the lithium battery is an original battery and / or the information related to thermal runaway to determine whether the lithium battery has aged;

[0025] If the lithium battery is not an original battery or the lithium battery has aged, the lithium battery charging circuit is controlled to be disconnected.

[0026] The beneficial effects of the above technical solutions are that the lithium battery safety management system actively judges whether the lithium battery is an original battery and whether the lithium battery is aging, controls to disconnect the lithium battery charging circuit when it is determined that the lithium battery is not an original battery or the lithium battery is aging, thereby completely disconnecting the charging function, cutting off the possibility of self-ignition caused by recharging, and ensuring the safety of the lithium battery. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Fig. 1 is a schematic diagram of a charger console, a lithium battery to be charged, and a lithium battery charging control unit connection structure of the present application;

[0028] In the figure, 1 is a charger console, 2 is a lithium battery to be charged, and 3 is a lithium battery charging control unit.

[0029] Figure 2 Fig. 2 is a principle block diagram of a lithium ion battery safety management system of the present application;

[0030] Figure 3 Fig. 3 is a flow chart of a lithium ion battery safety management method of the present application. DETAILED DESCRIPTION

[0031] System embodiment:

[0032] A lithium ion battery safety management system of the present application is used for real-time detection and safety management of a lithium battery to be charged 2 (hereinafter referred to as a battery). Figure 2 As shown in the figure, the management system includes a charger console 1, a lithium battery charging control unit 3, a thermal runaway information acquisition module, a battery information storage module, and a main control disconnecting module and an auxiliary disconnecting module.

[0033] The charger console 1 is a processor for overall operation and management control of the entire lithium ion battery safety management system, which can be an MCU, a PLC, etc. Figure 1 As shown in the figure, the lithium battery charging control unit 3 is connected to the outer wall thereof, and the charger console 1 and the lithium battery charging control unit 3 are in communication connection, for example, CAN communication.

[0034] The thermal runaway information acquisition module includes a battery internal information acquisition unit and an external environment information acquisition unit. The battery internal information acquisition unit mainly acquires some information inside the battery, including a CAN information acquisition unit, a battery temperature sensor, and a battery voltage sensor. The CAN information acquisition unit is connected with the BMS to acquire the battery's previous charging and discharging information from the BMS, including the charging start time, the charging end time, and the like; the battery temperature sensor is used to acquire the battery temperature; and the battery voltage sensor is used to acquire the battery voltage, including the total voltage of the battery and the voltage of each single battery. The external environment information acquisition unit mainly acquires the external environment information of the battery, including an environment temperature sensor used to acquire the temperature of the environment where the battery is located. The acquired information is all sent to the charger console for data processing, comparison, and the like to determine whether the battery is aging.

[0035] The battery information storage module includes a first storage unit and a second storage unit. The first storage unit is arranged at the lithium battery, and the lithium battery identification code is stored in the first storage unit. The lithium battery identification code is a number for distinguishing the lithium battery according to the factory date, model specification, product brand, and production sequence of the same production line. The first storage unit is arranged in the SD card, which is integrated and installed in the inner cavity of the battery. Moreover, the SD card data reader is also integrated and installed in the inner cavity of the battery. The charger console 1 is provided with a data connector matched with the SD card data reader, so that the charger console 1 can acquire the lithium battery information read by the SD card for identification. The second storage unit is arranged on the vehicle and also stores the lithium battery identification code, which is consistent with the lithium battery identification code stored in the first storage unit, for identification by the charger console 1. After the two lithium battery identification codes are identified by the charger console 1, comparison is performed. If the comparison result is consistent, it indicates that the battery is a factory battery (or it can be said that there is a legitimate factory record). Moreover, the battery identification code has read-only permission and contains a certain anti-tampering and information protection program, which reduces the possibility of rising safety hazards caused by tampering with the code to charge new batteries with old ones. This method can be used to combat pirated lithium batteries in business, improve the safety of original matching, and especially solve the phenomenon of unsafe third-party lithium batteries used by repair shops, which causes spontaneous combustion, low service life, or poor use endurance. Through the identification code of the storage battery and the factory record of the manufacturer, corresponding subsequent quality protection and maintenance can be provided, which is convenient for vehicle manufacturers to manage.

[0036] The main control disconnecting module is an electrically controlled switch, which is arranged in series in the charging circuit of the battery. Disconnecting the main control disconnecting module can achieve the purpose of preventing the battery from being charged and locking the battery. In the embodiment, the main control disconnecting module is connected to the lithium battery charging control unit and the charger control console. When the charger control console determines that the battery needs to be locked, it sends a control instruction to the lithium battery charging control unit, and the lithium battery charging control unit controls the main control disconnecting module to be disconnected, thereby sharing the task and pressure of the charger control console and ensuring the safe and reliable operation of the entire lithium ion battery safety management system.

[0037] The auxiliary disconnecting module includes a high-temperature automatic fuse (the melting point of the fuse is greater than 200℃, or a material with a corresponding melting point is used according to the temperature threshold of lithium battery combustion to achieve power-off at high temperature) and a temperature control switch. The fuse and the temperature control switch are also arranged in the charging circuit of the battery, and can achieve the purpose of disconnecting the charging circuit of the battery. The fuse is used for melting at high temperature, which is a physical control means. The temperature control switch is a conventional temperature control switch, which directly disconnects the charging circuit of the battery when the temperature of the battery is high (for example, when an external charging fault or combustion occurs), so as to prevent damage to the battery caused by high temperature. The temperature control switch can solve the problem that the combustion of the electric vehicle is too sudden and the combustion speed is too fast. The battery combustion phenomenon has a certain burstiness, and the burst fault has a large amount of temperature. In the design, a single fuse can be used for normal disconnection, but in the working process, the fuse has too low a use value for dealing with the combustion problem, and the melting point is low. For example, in the environment of direct sunlight, the temperature in the cavity of the vehicle is uncertain, and during driving, the heat dissipation efficiency of other components is not uniform, so the fuse cannot accurately and timely control. Therefore, the fuse is more used for disconnecting after combustion during charging.

[0038] After the main control disconnecting module or the auxiliary disconnecting module disconnects the charging circuit of the battery, a technician needs to carry out maintenance, and the battery can be restored only after the maintenance is qualified, thereby reducing the possibility of forced charging leading to combustion.

[0039] Based on the above lithium ion battery safety management system, a lithium ion battery safety management method of the present application can be realized (the entire method is realized by the charger control console), as shown in Figure 3 The method will be described in detail below.

[0040] In step one, the charger control console obtains the lithium battery identification codes from the first storage unit and the second storage unit, respectively. If the two lithium battery identification codes are consistent, it can be determined that the lithium battery is an original battery (i.e., there is a legitimate factory record). If it is not an original battery or does not have a legitimate factory record, a control instruction is sent to the lithium battery charging control unit, and the lithium battery charging control unit controls the main control disconnecting module to be disconnected, thereby achieving the purpose of locking the battery.

[0041] Step two, monitor the charging data of lithium ion battery. CAN information acquisition unit, battery temperature sensor and battery voltage sensor detect the battery in real time and send the collected data to the charger console to complete the routine monitoring of the charging information of the lithium battery. The charger console 1 controls the charging of the lithium battery according to the monitoring information to complete the routine charging. Moreover, the external environment information acquisition unit also detects the ambient temperature of the battery in real time and sends it to the charger console 1.

[0042] Step three, monitor the fault data of lithium battery. The charger console judges and processes the data detected in step two to determine the charging time of each charging and selects the abnormal charging data to determine the number of abnormal charging conditions.

[0043] Step four, determine the use of lithium battery. According to the data obtained from the CAN information acquisition module, the charger console can determine the charging time of each charging and calculate the total charging time from the factory to the present. The charger console can also count the number of abnormal charging conditions according to the charging and discharging information of each time, that is, when the charging time is greater than the set charging time threshold, the count is increased by one, and according to the charging time, the number of overcharging, the number of normal charging and the number of mild charging are divided to estimate the probability of battery aging according to the number of overcharging (the set charging time threshold in this embodiment is used to distinguish whether overcharging) and the total charging number to lock the lithium battery. The specific operation is: the charger console determines the total charging number of the lithium battery and the number of abnormal charging conditions (the condition that the charging time is greater than the set charging time threshold) according to the charging and discharging information of each time, and calculates the ratio of the number of abnormal charging and the total charging number. Moreover, the time of abnormal charging condition can also be counted to determine the time frequency of abnormal charging condition and calculate the overall distribution of abnormal charging condition to facilitate the judgment of battery aging and failure.

[0044] Step five, estimate the sudden accident or battery aging. According to the detection data in steps one and two and the calculation data in steps three and four, whether the battery is aging is judged: if the total charging time of the battery is long and the charging abnormal condition occurs frequently during charging, it can be estimated that the battery is aging; or the external environment of each charging is relatively harsh, which can also be estimated as aging. Both of these two conditions greatly increase the possibility of spontaneous combustion, which needs to be repaired or paid more attention.

[0045] Step six, the lithium battery is disconnected. In the case of battery aging, the charger console controls the main control module to disconnect the charging circuit of the lithium battery on the circuit board, cutting off the possibility of recharging and causing a fire. At this time, the lithium battery needs to be repaired or replaced by technical personnel after specific maintenance and judgment, reducing the possibility of fire.

[0046] The lithium battery disconnection operation in this embodiment includes two cases: the first is to directly disconnect the operation when it is determined that the battery is not an original battery, and the second is to disconnect the operation when the battery is an original battery but has aged. As other embodiments, only the lithium battery can be determined whether it is an original battery, and the lithium battery is disconnected when it is determined that it is not an original battery. Of course, only the battery can be determined whether it has aged, and the lithium battery is disconnected when it is determined that the battery has aged.

[0047] Method embodiment:

[0048] The lithium ion battery safety management method of the present application obtains the lithium battery identification code to determine whether the lithium battery is an original battery, and obtains the information related to thermal runaway to determine whether the lithium battery has aged. If the lithium battery is not an original battery or the lithium battery has aged, the lithium battery charging circuit is controlled to be disconnected.

[0049] As other embodiments, only the lithium battery identification code can be obtained to determine whether the lithium battery is an original battery, and the lithium battery charging circuit is controlled to be disconnected when it is determined that the lithium battery is not an original battery.

[0050] As other embodiments, only the information related to thermal runaway can be obtained to determine whether the lithium battery has aged, and the lithium battery charging circuit is controlled to be disconnected when it is determined that the lithium battery has aged.

[0051] The specific lithium battery identification code storage place, how to obtain the information related to thermal runaway, how to determine whether the lithium battery is an original battery, and how to determine whether the lithium battery has aged are described in detail in the system embodiment, and will not be repeated here.

Claims

1. A lithium-ion battery safety management system, characterized in that, It includes a charger control console, a lithium battery charging control unit, and a main control disconnect module, as well as a thermal runaway information acquisition module and / or a battery information storage module; The main control disconnect module is an electronically controlled switch used to disconnect the lithium battery charging circuit under the control of the charger control console; The thermal runaway information acquisition module is connected to the charger control console and is used to collect information related to thermal runaway and send it to the charging control console. The lithium battery charging control unit is communicatively connected to the charger console and controls the connection to the main control disconnect module. It is used to receive control commands from the charger console and execute the control commands to control the main control disconnect module to disconnect the lithium battery charging circuit. Both the charger console and the lithium battery charging control unit are located outside the lithium battery. The battery information storage module is connected to the charger control console and is used to transmit the stored lithium battery identification code to the charger control console. The lithium battery identification code is a number that distinguishes lithium batteries based on the manufacturing date, model specifications, product brand, and production sequence information of the same production line. The battery information storage module includes a first storage unit located at the lithium battery and a second storage unit located on the vehicle. Both the first and second storage units store lithium battery identification codes. The charger control console is used to determine whether the lithium battery is an original battery based on the lithium battery identification code stored in the first storage unit and the second storage unit and / or to determine whether the lithium battery is aging based on information related to thermal runaway. When it is determined that the lithium battery is not an original battery or that the lithium battery is aging, the main control disconnect module is activated to lock the lithium battery.

2. The lithium-ion battery safety management system according to claim 1, characterized in that, The safety management system also includes an auxiliary disconnection module, which includes a temperature control switch and / or a fuse, and is installed on the lithium battery charging circuit.

3. The lithium-ion battery safety management system according to claim 1, characterized in that, The thermal runaway information acquisition module includes an external environment information acquisition unit, which includes an ambient temperature sensor.

4. The lithium-ion battery safety management system according to claim 1, characterized in that, The thermal runaway information acquisition module includes an internal battery information acquisition unit, which comprises a CAN information acquisition unit, a battery temperature sensor, and a battery voltage sensor. The CAN information acquisition unit is used to connect to the BMS to obtain the battery's charging and discharging information from the BMS, including the charging duration. The battery temperature sensor is used to acquire the battery temperature, and the battery voltage sensor is used to acquire the battery voltage.

5. The lithium-ion battery safety management system according to claim 1, characterized in that, The charger control panel uses the following method to determine whether the lithium battery is aging: Based on the charging and discharging information from each charge / discharge cycle, determine the total charging time for the lithium battery. Based on the charging and discharging information from each cycle, determine the total number of charging cycles and the number of times charging anomalies occurred, and calculate the ratio of the number of charging anomalies to the total number of charging cycles. If the total charging time exceeds a set total time threshold and the ratio is greater than a set ratio threshold, then the lithium battery is determined to be aging.

6. The lithium-ion battery safety management system according to claim 5, characterized in that, The abnormal charging conditions include charging time exceeding the set charging time threshold.

7. The lithium-ion battery safety management system according to claim 1, characterized in that, The charger control panel uses the following method to determine whether the battery is original: if the lithium battery identification code stored in the first storage unit is the same as the lithium battery identification code stored in the second storage unit, then the lithium battery is original.

8. The lithium-ion battery safety management system according to claim 7, characterized in that, The first storage unit is located in an SD card, which is located inside the lithium battery cavity. The safety management system also includes an SD card data reader for reading the lithium battery identification code stored in the first storage unit and is connected to the charger control console to transmit the read lithium battery identification code to the charger control console.

9. A method for safety management of lithium-ion batteries, characterized in that, This method, applied to a lithium-ion battery safety management system as described in claim 1, includes the following steps: Obtain the lithium battery identification code to determine whether the lithium battery is an original battery and / or information related to thermal runaway to determine whether the lithium battery is aging; If the lithium battery is not an original battery or the lithium battery is aging, the lithium battery charging circuit will be disconnected.

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