Battery safety detection method and device and battery management system

Abstract

The application provides a battery safety detection method, device and battery management system. The battery safety detection method is used for detecting at least one battery monomer in a battery pack, comprising: acquiring the temperature of any battery monomer; determining the cumulative duration that any battery monomer is higher than a preset temperature according to the temperature of any battery monomer; calculating the integral of the temperature of any battery monomer in the time period corresponding to the cumulative duration as the damage degree of the packaging layer of any battery monomer; and determining the running condition of any battery monomer according to the damage degree of the packaging layer and the damage degree threshold of the packaging layer. In this way, the running condition of the battery monomer is determined according to the damage degree of the packaging layer, avoiding the safety accidents such as liquid leakage and explosion of the battery pack in the running process due to the aging of the packaging layer, and effectively improving the accuracy of battery safety detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery, in particular to a battery safety detection method and device and a battery management system. BACKGROUND

[0002] A battery is the power source of a mobile terminal, and provides long-time stable power supply for the mobile terminal. A lithium ion battery has many advantages, such as high energy density, fast charging and discharging rate, etc. However, the lithium ion battery also has some safety problems. For example, when a short circuit is caused by internal damage of the battery, heat is generated in the battery, and as the heat continuously accumulates, the battery may catch fire or burst, etc. Therefore, it is necessary to detect the safety of the battery to prevent accidents.

[0003] The existing battery safety detection method usually detects the temperature inside the battery, judges whether the temperature of the battery exceeds a preset temperature, and if so, performs a warning. However, only detecting the temperature of the battery has the problem of misjudgment, resulting in low accuracy of battery safety detection. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a battery safety detection method, device and battery management system to detect the safety of the battery and improve the accuracy of battery safety detection.

[0005] In a first aspect, the present application provides a battery safety detection method for detecting at least one battery cell in a battery pack, the method comprising: acquiring the temperature of any battery cell; determining the cumulative duration that the temperature of the any battery cell is higher than a preset temperature according to the temperature of the any battery cell; calculating the integral of the temperature of the any battery cell over a time period corresponding to the cumulative duration as the damage degree of the packaging layer of the any battery cell; and determining the running condition of the any battery cell according to the damage degree of the packaging layer and a damage degree threshold of the packaging layer.

[0006] In the above scheme, the temperature of the battery cell is first acquired in real time, when the current temperature of the battery cell is higher than the preset temperature, the integral of the current temperature of the battery cell over time is calculated, which is taken as the damage degree of the packaging layer of the battery cell, and finally the running condition of the battery cell is determined according to the damage degree of the packaging layer and the preset damage degree threshold of the packaging layer. In the time period corresponding to the cumulative duration that the current temperature of the battery cell is higher than the preset temperature, the integral of the current temperature of the battery cell over time is taken as the damage degree of the packaging layer of the battery cell, and the running condition of the battery cell is determined according to the damage degree of the packaging layer, which avoids the safety accidents such as liquid leakage and explosion of the battery pack during the running process caused by the aging of the packaging layer, and effectively improves the accuracy of battery safety detection.

[0007] In an optional implementation, the determining the operation condition of the any battery cell according to the packaging layer damage degree and the packaging layer damage degree threshold value comprises: determining a first ratio between the packaging layer damage degree of the any battery cell and the packaging layer damage degree threshold value; when the first ratio is greater than a first preset threshold value, determining that the any battery cell has a safety risk; and when the first ratio is less than the first preset threshold value, determining that the any battery cell does not have a safety risk.

[0008] In an optional implementation, the packaging layer damage degree threshold value is determined according to the packaging layer damage temperature and the standard service time under working conditions of the any battery cell.

[0009] In the above scheme, the packaging layer damage degree threshold value is determined according to the packaging layer damage temperature and the standard service time under working conditions, and the standard service time under working conditions is determined according to an existing lithium ion battery standard, so that the packaging layer damage degree threshold value conforms to the lithium ion battery standard, and the accuracy of battery safety detection is improved.

[0010] In an optional implementation, the method further comprises: for a batch of battery cells that do not constitute a battery pack, obtaining an effective sealing width of the batch of battery cells; determining a second ratio between the effective sealing width of the batch of battery cells and a sealing width under working conditions; when the second ratio is greater than a second preset threshold value, determining that the batch of battery cells does not have a safety risk; and when the second ratio is less than the second preset threshold value, determining that the batch of battery cells has a safety risk.

[0011] In the above scheme, the effective sealing width of each batch of battery cells is first obtained, and the effective sealing width of each batch of battery cells is compared with the sealing width under working conditions, so as to determine whether the batch of battery cells has a safety risk. Through the above manner, before the battery cells are selected to constitute a battery pack, it is determined whether the effective sealing width of each batch of battery cells meets the requirements, and the battery cells without a safety risk are used to constitute a battery pack in the subsequent use, so that the safety accidents such as liquid leakage and explosion of the battery pack in the running process caused by poor packaging are avoided.

[0012] In an optional implementation, the method comprises: determining the operation condition of the battery pack according to the operation condition of each battery cell in the battery pack; and when any battery cell has a safety risk, it is determined that the battery pack has a safety risk.

[0013] In the above scheme, each battery cell in the battery pack is subjected to safety detection, and it is determined whether each battery cell has a safety risk. When any battery cell in the battery pack has a safety risk, it is determined that the battery pack has a safety risk. Through the above manner, the operation condition of each battery cell in the battery pack is detected, and the accuracy of safety detection of the battery pack is improved.

[0014] In an optional embodiment, if the battery pack has a safety hazard, the method further comprises: issuing a battery cell lock instruction, the battery cell lock instruction being used to prohibit the battery cell with a safety hazard from charging or discharging.

[0015] In the above scheme, when the battery management system determines that a certain battery cell in the battery pack has a safety hazard, the battery management system issues a battery cell lock instruction, which prohibits the battery cell with a safety hazard from charging or discharging, thereby avoiding a safety accident of the battery pack.

[0016] In a second aspect, the present application provides a battery safety detection device for detecting at least one battery cell in a battery pack, the device comprising: a first acquisition module for acquiring the temperature of any battery cell; a first determination module for determining the cumulative duration for which the temperature of the any battery cell is higher than a preset temperature according to the temperature of the any battery cell; calculating the integral of the temperature of the any battery cell over the time period corresponding to the cumulative duration as the damage degree of the packaging layer of the any battery cell; and determining the operating condition of the any battery cell according to the damage degree of the packaging layer and a damage degree threshold of the packaging layer.

[0017] In an optional embodiment, the first determination module is specifically configured to determine a first ratio between the damage degree of the packaging layer of the any battery cell and the damage degree threshold of the packaging layer; when the first ratio is greater than a first preset threshold, it is determined that the any battery cell has a safety hazard; and when the first ratio is less than the first preset threshold, it is determined that the any battery cell does not have a safety hazard.

[0018] In an optional embodiment, the damage degree threshold of the packaging layer is determined according to the damage temperature of the packaging layer of the any battery cell and the standard service time under working conditions.

[0019] In an optional embodiment, the device further comprises a second acquisition module for acquiring the effective sealing width of a batch of battery cells that do not constitute a battery pack; and a second determination module for determining a second ratio between the effective sealing width of the batch of battery cells and the sealing width under working conditions; when the second ratio is greater than a second preset threshold, it is determined that the batch of battery cells does not have a safety hazard; and when the second ratio is less than the second preset threshold, it is determined that the batch of battery cells has a safety hazard.

[0020] In an optional embodiment, the device further comprises a third determination module for determining the operating condition of the battery pack according to the operating condition of each battery cell in the battery pack; wherein when any battery cell has a safety hazard, it is indicated that the battery pack has a safety hazard.

[0021] In an optional embodiment, if the battery pack has a safety hazard, the device further comprises an instruction sending module configured to send a battery cell locking instruction, the battery cell locking instruction being configured to prohibit charging or discharging of the battery cell having the safety hazard.

[0022] In a third aspect, the present application provides a battery management system, comprising: a collection module and a controller, the collection module and the controller being connected; the collection module is configured to collect the temperature of each battery cell in the battery; and the controller is configured to execute the method according to any one of the preceding embodiments.

[0023] In a fourth aspect, the present application provides a computer readable storage medium, the computer readable storage medium storing computer program instructions, the computer program instructions being read and executed by a computer to execute the method according to any one of the preceding embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0025] Figure 1 A structural schematic diagram of a battery management system provided by the embodiments of the present application;

[0026] Figure 2 A flowchart of a battery safety detection method provided by the embodiments of the present application;

[0027] Figure 3 A structural block diagram of a battery safety detection device provided by the embodiments of the present application. DETAILED DESCRIPTION

[0028] The technical solutions of the embodiments of the present application will be described below in combination with the drawings in the embodiments of the present application.

[0029] In order to monitor the safety of the battery and improve the accuracy of the battery safety detection, a battery safety detection method is provided in the embodiments of the present application. The present inventors have made research and exploration and proposed the following embodiments to solve the above problems.

[0030] Please refer to Figure 1A structural schematic diagram of a battery management system 100 applying a battery safety detection method is provided in the embodiments of the present application. The battery management system 100 can be installed on an electric vehicle, a drone or the like. In terms of structure, the battery management system 100 can include a collection module 101 and a controller 102.

[0031] The collection module 101 and the controller 102 are directly or indirectly electrically connected to realize data transmission or interaction. For example, the elements can be electrically connected to each other through one or more communication buses or signal lines. The above method includes at least one software or firmware (Firmware) form solidified in the controller 102.

[0032] The controller 102 can be an integrated circuit chip with signal processing capability. The controller 102 can also be a general-purpose processor, for example, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a discrete gate or transistor logic device, a discrete hardware component, which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application. In addition, the general-purpose processor can be a microprocessor or any conventional processor.

[0033] It should be noted that Figure 1 The structure shown is only schematic, and the battery management system 100 provided in the embodiments of the present application can also have fewer or more components, or have a different configuration from that shown. Figure 1 More components, or have a different configuration from that shown. Figure 1

[0034] Please refer to Figure 2 , Figure 2 A flowchart of a battery safety detection method provided in the embodiments of the present application is shown. The method includes the following steps.

[0035] Step S201: Obtain the temperature of any battery monomer.

[0036] Step S202: Determine the cumulative duration that any battery monomer is higher than the preset temperature according to the temperature of any battery monomer.

[0037] Step S203: Calculate the integral of the temperature of any battery monomer in the time period corresponding to the cumulative duration as the damage degree of the packaging layer of any battery monomer.

[0038] Step S204: Determine the running condition of any battery monomer according to the damage degree of the packaging layer and the damage degree threshold of the packaging layer.

[0039] ​In summary, in the embodiment of the present application, firstly, the temperature of the battery monomer is acquired in real time, when the current temperature of the battery monomer is higher than the preset temperature, the integral of the current temperature of the battery monomer in time is calculated, the integral is taken as the damage degree of the packaging layer of the battery monomer, and finally the running condition of the battery monomer is determined according to the damage degree of the packaging layer and the preset damage degree threshold of the packaging layer. In the time period corresponding to the cumulative time length when the current temperature of the battery monomer is higher than the preset temperature, the integral of the current temperature of the battery monomer in time is taken as the damage degree of the packaging layer of the battery monomer, and the running condition of the battery monomer is determined according to the damage degree of the packaging layer, so as to avoid the safety accidents such as liquid leakage and explosion of the battery pack in the running process due to the aging of the packaging layer, and effectively improve the accuracy of battery safety detection.

[0040] The complete process of the above battery safety detection method will be described below in combination with specific examples.

[0041] Step S201: acquire the temperature of any battery monomer.

[0042] It should be noted that a battery pack is composed of a plurality of battery monomers. The battery safety detection method provided in the embodiment of the present application can detect the safety of each battery monomer in the battery pack, and the battery safety detection method will be described below taking one battery monomer as an example.

[0043] Each battery monomer is connected with a battery management system. One or more temperature sensors (i.e. the acquisition module of the battery management system) are arranged on the surface of each battery monomer. The number of temperature sensors arranged on the battery monomer is related to the risk degree of each battery monomer in the battery pack. The higher the risk degree of the battery monomer, the more temperature sensors are arranged.

[0044] For example, a battery pack is composed of 9 battery monomers arranged from left to right, and the 9 battery monomers are numbered 1-9 from left to right for convenience. The risk degrees of the battery monomers numbered 4, 5 and 6 are defined as high risk degrees, and the risk degrees of the remaining battery monomers are defined as low risk degrees. Three temperature sensors are arranged on the battery monomers with high risk degrees, and two temperature sensors are arranged on the battery monomers with low risk degrees.

[0045] It can be understood that the above example is only one setting mode of the temperature sensor provided in the embodiment of the present application, and the present application is not limited thereto, and the setting mode of the temperature sensor can be flexibly determined by the person skilled in the art according to the actual situation.

[0046] During the working of the battery pack, the temperature sensor collects temperature every preset time interval and sends the temperature to the controller of the battery management system. The preset time interval can be 0.1-1s, which is not limited in the present application. If only one temperature sensor is arranged on the battery monomer, the temperature collected by the temperature sensor is the temperature of the battery monomer. If multiple temperature sensors are arranged on the battery monomer, the average value of the temperatures collected by the multiple temperature sensors is taken as the temperature of the battery monomer.

[0047] Step S202: determining the cumulative duration that any battery monomer is higher than the preset temperature according to the temperature of any battery monomer.

[0048] Step S203: calculating the integral of the temperature of any battery monomer in the time period corresponding to the cumulative duration as the damage degree of the packaging layer of any battery monomer.

[0049] In the embodiments of the present application, after the temperature of the battery monomer is acquired in real time, the temperature of the battery monomer is compared with the preset temperature to determine the cumulative duration that the battery monomer is higher than the preset temperature. The preset temperature is the aging and damage temperature of the packaging layer of the battery monomer. When the temperature of the battery monomer is higher than the preset temperature for a long time, the battery monomer will leak or explode. The preset temperature is determined according to the material of the battery monomer. For example, when the battery monomer is a soft-pack battery, the preset temperature is 35℃; when the battery monomer is a cylindrical battery or a square shell battery, the preset temperature is 65℃.

[0050] After the cumulative duration that the battery monomer is higher than the preset temperature is determined, the integral of the temperature of the battery monomer in the time period corresponding to the cumulative duration is calculated, which is the damage degree of the packaging layer of the battery monomer.

[0051] It can be understood that when the temperature of the battery monomer is higher than the preset temperature (the aging and damage temperature of the packaging layer of the battery monomer), the packaging layer of the battery monomer will be damaged to a certain extent. The longer the time that the temperature of the battery monomer is higher than the preset temperature, the greater the damage degree of the packaging layer of the battery monomer. In the embodiments of the present application, the integral of the temperature of the battery monomer in the time period corresponding to the cumulative duration is calculated to determine the damage degree of the packaging layer of the battery monomer.

[0052] The damage degree of the packaging layer of the battery monomer is determined by the following formula:

[0053]

[0054] In the formula, Y is the damage degree of the packaging layer, T(t) is the temperature-time curve of the battery monomer, the ordinate of T(t) is the temperature of the battery monomer when the battery monomer is higher than the preset temperature, and the abscissa is the time corresponding to the temperature of the battery monomer when the battery monomer is higher than the preset temperature, a n is the starting time point of the nth time that the battery monomer is higher than the preset temperature, and bn the end time point of the n th time that the battery cell is higher than the preset temperature.

[0055] It can be understood that the battery management system acquires the temperature of the battery cell in real time, and compares the temperature of the battery cell with the preset temperature. When the temperature of the battery cell is higher than the preset temperature for the first time (the time point at this time is a1), the temperature-time curve of the battery cell is drawn; when the temperature of the battery cell is lower than the preset temperature (the time point at this time is b1), the drawing of the curve is ended. Wherein, a1 corresponds to the 0th moment, and b1 corresponds to the duration of the first time that the battery cell is higher than the preset temperature.

[0056] When the temperature of the battery cell is higher than the preset temperature for the second time (the time point at this time is a2), the temperature-time curve of the battery cell is drawn again; when the temperature of the battery cell is lower than the preset temperature (the time point at this time is b2), the drawing of the curve is ended. Wherein, a2 corresponds to the 0th moment, and b2 corresponds to the duration of the second time that the battery cell is higher than the preset temperature.

[0057] It can be seen that each time the temperature of the battery cell is higher than the preset temperature, a temperature-time curve of the battery cell is determined. The temperature-time curves of each battery cell are integrated, and the integrals of the curves are accumulated to determine the damage degree of the packaging layer of the battery cell.

[0058] Step S204: determining the running condition of any battery cell according to the damage degree of the packaging layer and the damage degree threshold of the packaging layer.

[0059] In the embodiment of the application, after the damage degree of the packaging layer of the battery cell is determined, the controller of the battery management system is preset with a damage degree threshold of the packaging layer, and the running condition of the battery cell is determined by comparing the damage degree of the packaging layer with the damage degree threshold of the packaging layer.

[0060] According to the foregoing damage degree of the packaging layer, the damage degree of the packaging layer represents the damage degree of the packaging layer of the battery cell. When the damage degree of the packaging layer reaches the damage degree threshold of the packaging layer, it means that the packaging layer of the battery cell has been seriously damaged, and there will be safety hazards such as liquid leakage and fire. Therefore, in the embodiment of the application, the controller of the battery management system determines the running condition of the battery cell by comparing the damage degree of the packaging layer with the damage degree threshold of the packaging layer.

[0061] As an optional implementation, the above step S204 can include the following contents:

[0062] determining whether the damage degree of the packaging layer of any battery cell is greater than the damage degree threshold of the packaging layer;

[0063] if greater, determining that any battery cell has a safety hazard;

[0064] If less, it is determined that any battery monomer does not exist security risks.

[0065] It can be understood that, in the embodiments of the present application, whether the battery monomer exists security risks is determined by judging the size relationship between the packaging layer damage degree of the battery monomer and the packaging layer damage degree threshold.

[0066] As another optional implementation, the above step S204 can include the following contents:

[0067] Determine the first ratio between the packaging layer damage degree of any battery monomer and the packaging layer damage degree threshold;

[0068] When the first ratio is greater than the first preset threshold, it is determined that any battery monomer exists security risks;

[0069] When the first ratio is less than the first preset threshold, it is determined that any battery monomer does not exist security risks.

[0070] Specifically, the first ratio between the packaging layer damage degree of the battery monomer and the packaging layer damage degree threshold is determined, if the first ratio is greater than the first preset threshold, it is determined that the battery monomer exists security risks; if the first ratio is less than the first preset threshold, it is determined that the battery monomer does not exist security risks.

[0071] It should be noted that there are many ways to determine the packaging layer damage degree threshold.

[0072] Optionally, the plurality of battery monomers are subjected to charge-discharge cycle test in advance, and in the charge-discharge cycle test process, the packaging layer damage degree of each battery monomer is calculated by using the foregoing steps S101-S103, and the packaging layer damage degree when the packaging layer of each battery monomer is damaged is recorded. The packaging layer damage degrees when the packaging layers of the battery monomers are damaged are averaged to determine the packaging layer damage degree threshold.

[0073] Optionally, the packaging layer damage degree threshold is determined according to the packaging layer damage temperature of the battery monomer and the standard service time of the working condition. It should be noted that the packaging layer damage temperature of the battery monomer is the aforementioned packaging layer aging damage temperature, that is, when the temperature of the battery monomer is higher than the packaging layer aging damage temperature for a long time, the battery monomer will leak or explode. For example, when the battery monomer is a soft package battery, the packaging layer damage temperature is 35°C.

[0074] The standard service time of the working condition is determined according to the existing lithium ion battery standard, for example, for the battery monomer applied to electric bicycles, according to the content specified in GB36972-2018, the standard service time of the working condition is 3000 hours; for the battery monomer applied to the field of electronic energy storage, according to the content specified in GB36276-2018, the standard service time of the working condition is 5000 hours.

[0075] The encapsulation layer damage degree threshold value is determined by the following formula:

[0076] X = T1*t1

[0077] Wherein, X is the encapsulation layer damage degree threshold value, T1 is the encapsulation layer damage temperature of the battery monomer, and t1 is the service standard time of the battery monomer under working conditions.

[0078] Further, after determining the encapsulation layer damage degree threshold value by the above formula, whether the battery monomer has a safety hazard can be determined based on the following formula:

[0079]

[0080] If W>1, it indicates that the battery monomer has a safety hazard; if W<1, it indicates that the battery monomer does not have a safety hazard.

[0081] It can be understood that in the above formula, W is the first ratio between the encapsulation layer damage degree of the battery monomer and the encapsulation layer damage degree threshold value, and 1 is the first preset threshold value. It should be noted that the first preset threshold value of 1 is only one case provided by the embodiments of the present application. In other embodiments, the first preset threshold value can also be 0.9, 0.8, etc. The present application does not make specific limitations on this.

[0082] Further, the battery safety detection method provided by the embodiments of the present application further includes the following content:

[0083] For a batch of battery monomers that do not constitute a battery pack, the effective sealing width of the batch of battery monomers is obtained;

[0084] A second ratio between the effective sealing width of the batch of battery monomers and the service sealing width under working conditions is determined;

[0085] When the second ratio is greater than a second preset threshold value, it is determined that the batch of battery monomers does not have a safety hazard;

[0086] When the second ratio is less than the second preset threshold value, it is determined that the batch of battery monomers has a safety hazard.

[0087] It should be noted that the battery pack is composed of a plurality of battery monomers. If the effective sealing width of the battery monomers constituting the battery pack is small, liquid leakage or explosion may also occur during the working process of the battery pack. Therefore, the effective sealing width of each battery monomer is detected before the battery monomers constitute the battery pack.

[0088] In the embodiments of the present application, the battery monomer is a soft package battery.

[0089] Specifically, when the effective sealing width of the battery cell is obtained, the top sealing edge of the battery cell is torn off by a tensile testing machine, and then the residual sealing width of the battery cell is measured by a microscope, and the residual sealing width is the effective sealing width of the battery cell. It can be understood that the specific measurement process of the effective sealing width of the battery cell can refer to the prior art, and the specific details are not described here.

[0090] Since determining the effective sealing width of the battery cell will cause damage to the battery cell, so that the measured battery cell cannot be used continuously. The embodiments of the application consider that the effective sealing widths of the battery cells in the same batch are basically the same, and a plurality of battery cells are taken from the same batch of battery cells, and the effective sealing width of each selected battery cell is determined in the above manner. When the effective sealing widths of the battery cells satisfy the normal distribution, the average value of the effective sealing widths of the battery cells is taken as the effective sealing width of the battery cells in the batch.

[0091] The working condition service sealing width is used to represent the effective sealing width of the battery cell meeting the standard. If the effective sealing width of a batch of battery cells is greater than the working condition service sealing width, it is considered that the batch of battery cells meets the use standard and can form a battery pack. If the effective sealing width of the batch of battery cells is less than the working condition service sealing width, it is considered that the batch of battery cells does not meet the use standard and has a safety hazard.

[0092] The working condition service sealing width is determined according to the existing lithium ion battery standard. For example, for the battery cell applied to the electric bicycle, according to the content specified in GB36972-2018, the working condition service sealing width is 3.5 mm; for the battery cell applied to the electronic energy storage field, according to the content specified in GB36276-2018, the working condition service sealing width is 6 mm.

[0093] Specifically, whether a batch of battery cells has a safety hazard is determined by the following formula:

[0094]

[0095] If Z>1, it indicates that the batch of battery cells has no safety hazard; if Z<1, it indicates that the batch of battery cells has a safety hazard.

[0096] Wherein, L represents the effective sealing width of the batch of battery cells, and L1 represents the working condition service sealing width of the batch of battery cells.

[0097] It can be understood that, in the above formula, Z is the second ratio, and 1 is the second preset threshold. It should be noted that the first preset threshold of 1 is only one case provided by the embodiment of the present application. In other embodiments, the first preset threshold can also be 1.1, 1.2, etc. The present application does not make specific limitations on this.

[0098] In the above scheme, the effective sealing width of each batch of battery monomers is first obtained, and the effective sealing width of each batch of battery monomers is compared with the working condition service sealing width, so as to determine whether the batch of battery monomers has a safety hazard. Through the above-mentioned manner, before selecting the battery monomers to form the battery pack, it is determined whether the effective sealing width of each batch of battery monomers meets the requirements, and the battery monomers without safety hazards are used to form the battery pack in the subsequent use, so as to avoid the safety accidents such as liquid leakage and explosion of the battery pack in the running process due to poor packaging.

[0099] In addition, the battery safety detection method provided by the embodiment of the present application further includes the following contents:

[0100] According to the running condition of each battery monomer in the battery pack, the running condition of the battery pack is determined.

[0101] When any battery monomer has a safety hazard, it is indicated that the battery pack has a safety hazard.

[0102] It can be understood that, in the embodiment of the present application, the battery management system performs safety detection on each battery monomer in the battery pack, and determines whether each battery monomer has a safety hazard. When any one of the battery monomers in the battery pack has a safety hazard, it is determined that the battery pack has a safety hazard.

[0103] Further, if the battery pack has a safety hazard, the battery safety detection method provided by the embodiment of the present application further includes the following contents:

[0104] The battery monomer locking instruction is issued, and the battery monomer locking instruction is used to prohibit the battery monomer with a safety hazard from charging or discharging.

[0105] In the embodiment of the present application, when the battery management system determines that a certain battery monomer in the battery pack has a safety hazard, in order to avoid the risk of fire or explosion of the battery monomer in the charging and discharging process, the battery management system issues a battery monomer locking instruction, and prohibits the battery monomer with a safety hazard from charging or discharging through the battery monomer locking instruction, so as to avoid safety accidents of the battery pack.

[0106] Based on the same inventive concept, the embodiment of the present application also provides a battery safety detection device. Please refer to Figure 3 , Figure 3A structural block diagram of a battery safety detection device is provided for an embodiment of the present application. The battery safety detection device 300 is used to detect at least one battery cell in a battery pack. The battery safety detection device 300 can include:

[0107] A first acquisition module 301 is configured to acquire the temperature of any battery cell.

[0108] A first determination module 302 is configured to determine the cumulative duration for which the temperature of the any battery cell is higher than a preset temperature according to the temperature of the any battery cell; calculate the integral of the temperature of the any battery cell over a time period corresponding to the cumulative duration as a packaging layer damage degree of the any battery cell; and determine the operation condition of the any battery cell according to the packaging layer damage degree and a packaging layer damage degree threshold.

[0109] In an optional embodiment, the first determination module 302 is specifically configured to determine a first ratio between the packaging layer damage degree of the any battery cell and the packaging layer damage degree threshold; when the first ratio is greater than a first preset threshold, determine that the any battery cell has a safety risk; and when the first ratio is less than the first preset threshold, determine that the any battery cell does not have a safety risk.

[0110] In an optional embodiment, the packaging layer damage degree threshold is determined according to the packaging layer damage temperature of the any battery cell and a standard service time under working conditions.

[0111] In an optional embodiment, the device further includes a second acquisition module 303 configured to acquire an effective sealing width of a batch of battery cells that do not constitute a battery pack; and a second determination module 304 configured to determine a second ratio between the effective sealing width of the batch of battery cells and a working condition service sealing width; when the second ratio is greater than a second preset threshold, determine that the batch of battery cells does not have a safety risk; and when the second ratio is less than the second preset threshold, determine that the batch of battery cells has a safety risk.

[0112] In an optional embodiment, the device further includes a third determination module 305 configured to determine the operation condition of the battery pack according to the operation condition of each battery cell in the battery pack; and when any battery cell has a safety risk, the battery pack is characterized by having a safety risk.

[0113] In an optional embodiment, if the battery pack has a safety risk, the device further includes an instruction sending module 306 configured to send a battery cell lock instruction, the battery cell lock instruction being used to prohibit the battery cell having a safety risk from being charged or discharged.

[0114] It should be noted that, since those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

[0115] In addition, the embodiment of the present application further provides a computer readable storage medium, the computer readable storage medium has computer program instructions stored thereon, when the computer program instructions are read and run by a computer, the battery safety detection method is executed as in the foregoing embodiment.

[0116] The storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)), etc.

[0117] In the embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some communication interface, and can be electrical, mechanical or other forms.

[0118] In addition, the units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. According to actual needs, some or all of the units can be selected to achieve the purpose of the embodiment.

[0119] Furthermore, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0120] It should be noted that, if the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product in essence or in the form of a part or the technical solutions of the present application that make contributions to the prior art. The computer software product is stored in a storage medium, includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0121] In this document, relational terms such as first and second and the like can merely be used to distinguish one entity or action from another, without necessarily requiring or implying any such actual relationship or order between or among the entities or actions.

[0122] The above only describes the embodiments of the present application and is not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery safety detection method, characterized in that: For detecting at least one battery cell in a battery pack, the method comprises: Get the temperature of any battery cell; determining, based on the temperature of any battery cell, a cumulative time during which the temperature of any battery cell is higher than a preset temperature; Calculating the integral of the temperature of any battery cell over the time period corresponding to the accumulated time as the damage degree of the packaging layer of any battery cell; The operating condition of any one of the battery cells is determined based on the encapsulation layer damage degree and the encapsulation layer damage degree threshold, wherein the encapsulation layer damage degree threshold is determined based on the encapsulation layer damage temperature and the standard service time under working conditions of any one of the battery cells, and is positively correlated with the encapsulation layer damage temperature or the standard service time under working conditions.

2. The method according to claim 1, characterized in that The determining the operating condition of any one of the battery cells according to the damage degree of the encapsulation layer and the damage threshold of the encapsulation layer includes: determining a first ratio between a damage degree of the encapsulation layer of any one of the battery cells and a damage degree threshold of the encapsulation layer; When the first ratio is greater than a first preset threshold, determining that any of the battery cells has a safety hazard; When the first ratio is less than a first preset threshold, it is determined that there is no safety hazard in any of the battery cells.

3. The method according to claim 1, characterized in that The method further comprises: For a batch of battery cells that are not formed into a battery pack, obtaining an effective seal width of the batch of battery cells; Determining a second ratio between the effective seal width and the service seal width of the battery cells of the batch; When the second ratio is greater than a second preset threshold, it is determined that there is no safety hazard in the batch of battery cells; When the second ratio is less than a second preset threshold, it is determined that there is a safety hazard in the batch of battery cells.

4. The method according to claim 1, wherein The method comprises: determining an operating condition of the battery pack according to an operating condition of each battery cell in the battery pack; Wherein, when any battery cell has a safety hazard, it indicates that the battery pack has a safety hazard.

5. The method according to claim 4, characterized in that If the battery pack has a safety hazard, the method further includes: A battery cell locking instruction is issued, wherein the battery cell locking instruction is used to prohibit the battery cell with potential safety hazards from charging or discharging.

6. A battery safety detection device, characterized in that: For detecting at least one battery cell in a battery pack, the device comprises: A first acquisition module is used to acquire the temperature of any battery cell; The first determination module is used to determine the cumulative time that any battery cell is above a preset temperature based on the temperature of any battery cell; calculate the integral of the temperature of any battery cell over a time period corresponding to the cumulative time as the degree of damage to the packaging layer of any battery cell; and determine the operating condition of any battery cell based on the degree of damage to the packaging layer and a threshold value for the degree of damage to the packaging layer, wherein the threshold value for the degree of damage to the packaging layer is determined based on the damage temperature of the packaging layer and the standard service time under working conditions of any battery cell, and is positively correlated with the damage temperature of the packaging layer or the standard service time under working conditions.

7. The device according to claim 6, characterized in that The first determining module is specifically configured to determine a first ratio between a damage degree of the encapsulation layer of the any battery cell and the encapsulation layer damage threshold; when the first ratio is greater than a first preset threshold, determining that the any battery cell has a safety hazard; When the first ratio is less than a first preset threshold, it is determined that there is no safety hazard in any of the battery cells.

8. A battery management system, characterized in that: include: A collection module and a controller, the collection module and the controller are connected; the collection module is used to collect the temperature of each battery cell in the battery; The controller is configured to execute the method according to any one of claims 1 to 5.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, and when the computer program instructions are read and executed by a computer, the method according to any one of claims 1 to 5 is executed.

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