A method and device for detecting the aging of an electric cell

Abstract

An embodiment of the present invention discloses a method and a device for detecting the aging of an electric core. The detection method includes: determining the charge-discharge stage of the electric core to be measured; calculating the first heat and the second heat of the electric core to be measured based on the mass, the comprehensive specific heat capacity, and the temperature of the electric core to be measured respectively; calculating the proportion of reversible heat of the electric core to be measured based on the first heat and the second heat; and determining whether there is an aging problem with the electric core to be measured based on the proportion of reversible heat. By dividing the charge-discharge stage of the electric core to be measured, calculating the proportion of reversible heat using the heat generated by the electric core to be measured in each charge-discharge stage, and finally determining whether there is an aging problem with the electric core to be measured using the proportion of reversible heat, the present application solves the technical problem that there is no detection of the aging problem of the battery using the temperature change characteristics in the prior art, realizes the technical effect of being able to monitor the aging state of the electric core online using the temperature change characteristics of the electric core, simplifies the operation process of the detection, and reduces the detection cost.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of battery detection, and in particular, to a method and a device for detecting the aging of battery cells. Background Art

[0002] Currently, regarding the attenuation and safety applications of batteries, the temperature characteristics of battery cells are mainly used in thermal runaway. However, from the perspective of electrochemical energy conversion and basic principles, the temperature characteristics of batteries are an important indicator of battery life.

[0003] The real-time operating data of the current battery temperature can be collected and stored by mature sensor device technologies, and can be detected by batch high-speed online calculation through a computing power system to obtain the heat change state of the battery. However, there are relatively few methods for characterizing the battery capacity or life attenuation analysis using heat factors, resulting in a lack of using the temperature change characteristics of batteries in the detection of battery operating states. Summary of the Invention

[0004] The embodiments of the present invention provide a method and a device for detecting the aging of battery cells, which solve the technical problem that there is no technology for detecting the aging problem of batteries using temperature change characteristics in the prior art.

[0005] The embodiments of the present invention provide a method for detecting the aging of battery cells, and the detection method includes:

[0006] Determine the charge and discharge stages of the battery cell to be tested;

[0007] Based on the mass, overall specific heat capacity, and temperature of the battery cell to be tested, calculate the first heat and the second heat of the battery cell to be tested respectively, where the first heat is the total heat generated by the battery cell to be tested in each charging stage, and the second heat is the total heat generated by the battery cell to be tested in each discharging stage;

[0008] Calculate the reversible heat ratio of the battery cell to be tested based on the first heat and the second heat;

[0009] Determine whether there is an aging problem with the battery cell to be tested based on the reversible heat ratio.

[0010] Further, calculating the first heat and the second heat of the battery cell to be tested based on the mass, overall specific heat capacity, and temperature of the battery cell to be tested includes:

[0011] Determine the specific heat capacity mass coefficient of the battery cell to be tested based on the mass and overall specific heat capacity of the battery cell to be tested;

[0012] Calculate the heat of each charge and discharge stage respectively using the specific heat capacity mass coefficient and the temperature of the battery cell to be tested;

[0013] Sum up the heat of each charge-discharge stage respectively calculated to obtain the first heat and the second heat.

[0014] Further, determining the specific heat capacity mass coefficient of the battery cell under test based on the mass and the comprehensive specific heat capacity of the battery cell under test includes:

[0015] Based on the mass of the battery cell under test and the comprehensive specific heat capacity, use the first formula:

[0016]

[0017] Determine the specific heat capacity mass coefficient of the battery cell under test;

[0018] where, CM Cell (t) is the specific heat capacity mass coefficient at time t, C j (t) is the comprehensive specific heat capacity at time t, M j (t) is the mass of different materials in the battery cell under test at time t, and j is the number of material types of the battery cell under test.

[0019] Further, calculating the heat of each charge-discharge stage respectively using the specific heat capacity mass coefficient and the temperature of the battery cell under test includes:

[0020] Using the specific heat capacity mass coefficient and the temperature of the battery cell under test, according to the second formula:

[0021]

[0022] Calculate the heat of each charge-discharge stage respectively; where, ΔQ(t n ) is the heat of each charge-discharge stage, CM Cell (t) is the specific heat capacity mass coefficient at time t, ΔT(t n ) is the temperature of the battery cell under test at time t, Δt n is the duration of each charge-discharge stage, and n is the number of time periods divided in one charge stage or one discharge stage.

[0023] Further, summing up the heat of each charge-discharge stage respectively calculated to obtain the first heat and the second heat includes:

[0024] Using the third formula:

[0025]

[0026] Calculate the first heat, where, Q Char is the first heat, ΔQ(t Char-i) is the heat of the cell under test at each charging stage calculated according to the second formula, and Char-i is the number of marked time periods at each charging stage of the cell under test;

[0027] Using the fourth formula:

[0028]

[0029] Calculate the second heat, where Q Dis is the second heat, and ΔQ(t Dis-i ) is the heat of the cell under test at each discharging stage calculated according to the second formula, and Dis-i is the number of marked time periods at each discharging stage of the cell under test.

[0030] Furthermore, calculating the reversible heat ratio of the cell under test based on the first heat and the second heat includes:

[0031] Using the fifth formula: Calculate the reversible heat ratio of the cell under test, where Q Char is the first heat, Q Dis is the second heat, and η rev (t) is the reversible heat ratio of the cell under test.

[0032] Furthermore, determining whether the cell under test has an aging problem based on the reversible heat ratio includes:

[0033] Comparing the reversible heat ratio with a preset empirical heat threshold;

[0034] If the reversible heat ratio is less than the preset empirical heat threshold, the cell under test has an aging problem.

[0035] Furthermore, determining the charging and discharging stages of the cell under test includes:

[0036] Detecting the current direction of the cell under test within a preset time period, and determining the charging and discharging stages of the cell under test within the preset time period based on the detected current direction.

[0037] An embodiment of the present invention also provides a detection device for cell aging, and the detection device includes:

[0038] A stage determination unit for determining the charging and discharging stages of the cell under test;

[0039] The first heat calculation unit is configured to calculate the first heat and the second heat of the battery cell to be measured based on the mass, the comprehensive specific heat capacity, and the temperature of the battery cell to be measured, where the first heat is the total heat generated by the battery cell to be measured in each charging stage, and the second heat is the total heat generated by the battery cell to be measured in each discharging stage;

[0040] The second heat calculation unit is configured to calculate the proportion of reversible heat of the battery cell to be measured based on the first heat and the second heat;

[0041] The battery cell detection unit is configured to determine whether there is an aging problem with the battery cell to be measured based on the proportion of reversible heat.

[0042] Further, the first heat calculation unit includes:

[0043] A coefficient calculation subunit is configured to determine the specific heat capacity mass coefficient of the battery cell to be measured based on the mass and the comprehensive specific heat capacity of the battery cell to be measured;

[0044] The first heat calculation subunit is configured to calculate the heat of each charge and discharge stage by using the specific heat capacity mass coefficient and the temperature of the battery cell to be measured;

[0045] The second heat calculation subunit is configured to add up the calculated heat of each charge and discharge stage to obtain the first heat and the second heat.

[0046] An embodiment of the present invention discloses a method and a device for detecting the aging of a battery cell. The detection method includes: determining the charge and discharge stages of the battery cell to be measured; calculating the first heat and the second heat of the battery cell to be measured based on the mass, the comprehensive specific heat capacity, and the temperature of the battery cell to be measured; calculating the proportion of reversible heat of the battery cell to be measured based on the first heat and the second heat; and determining whether there is an aging problem with the battery cell to be measured based on the proportion of reversible heat. In this application, by dividing the charge and discharge stages of the battery cell to be measured and calculating the proportion of reversible heat by using the heat generated by the battery cell to be measured in each charge and discharge stage, and finally determining whether there is an aging problem with the battery cell to be measured by using the proportion of reversible heat, the technical problem that there is no detection of the aging problem of the battery by using the temperature change characteristics in the prior art is solved, the technical effect of being able to monitor the aging state of the battery cell online by using the temperature change characteristics of the battery cell is achieved, the calculation process of the detection is simplified, and the detection cost is reduced. Description of the Drawings

[0047] Figure 1 is a flowchart of a method for detecting the aging of a battery cell provided by an embodiment of the present invention;

[0048] Figure 2 is a schematic diagram of the division of the charge and discharge stages of a battery cell to be measured provided by an embodiment of the present invention;

[0049] Figure 3 It is a schematic diagram for dividing the charge-discharge energy ratio of the battery cell to be tested provided by an embodiment of the present invention;

[0050] Figure 4 It is a flowchart of another method for detecting the aging of a battery cell provided by an embodiment of the present invention;

[0051] Figure 5 It is a structural diagram of a device for detecting the aging of a battery cell provided by an embodiment of the present invention. Detailed implementation manners

[0052] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of convenience of description, only parts related to the present invention are shown in the drawings rather than all the structures.

[0053] It should be noted that the terms "first", "second", etc. in the specification, claims and drawings of the present invention are used to distinguish different objects, rather than to limit a specific order. Each of the following embodiments of the present invention can be executed independently, and the embodiments can also be combined with each other for execution. The embodiments of the present invention do not make specific limitations in this regard.

[0054] Figure 1 It is a flowchart of a method for detecting the aging of a battery cell provided by an embodiment of the present invention.

[0055] As Figure 1 shown, the method for detecting the aging of the battery cell specifically includes:

[0056] S101, determining the charge-discharge stage of the battery cell to be tested.

[0057] Specifically, during the use of the battery cell to be tested, there may be multiple charging or discharging stages within a period of time. Figure 2 It is a schematic diagram for dividing the charge-discharge stage of a battery cell to be tested provided by an embodiment of the present invention. Assuming that there are multiple charge-discharge processes of the battery cell to be tested within a period of time, as Figure 2 shown, it is divided into six segments in total. The first segment is the discharging stage, the second segment is the charging stage, the third segment is the charging stage, the fourth segment is the discharging stage, the fifth segment is the charging stage, and the sixth segment is the discharging stage.

[0058] Optionally, S101 specifically includes: detecting the current direction of the battery cell to be tested within a preset duration, and determining the charge-discharge stage of the battery cell to be tested within the preset duration based on the detected current direction.

[0059] Specifically, the charging or discharging state of the battery cell to be measured at the current time can be marked by detecting the current direction in the battery cell to be measured. To improve the detection efficiency and reduce the detection operation amount, usually, the charging and discharging process of the battery cell to be measured within a period of time is divided, that is, the current direction of the battery cell to be measured within a preset duration is detected to divide the charging and discharging stages within the preset duration.

[0060] S102, calculate the first heat quantity and the second heat quantity of the battery cell to be measured based on the mass, the comprehensive specific heat capacity, and the temperature of the battery cell to be measured, where the first heat quantity is the total heat quantity generated by the battery cell to be measured in each charging stage, and the second heat quantity is the total heat quantity generated by the battery cell to be measured in each discharging stage.

[0061] Specifically, after dividing the charging and discharging stages of the battery cell to be measured within the preset duration, calculate the total heat quantity generated in each charging stage, that is, the above-mentioned first heat quantity, and the total heat quantity in each discharging stage, that is, the above-mentioned second heat quantity. As Figure 2 shown, taking the charging and discharging stages of the battery cell to be measured in Figure 2 as an example, the first heat quantity is the sum of the heat quantities in the second, third, and fifth segments, and the second heat quantity is the sum of the heat quantities in the first, fourth, and sixth segments.

[0062] S103, calculate the proportion of the reversible heat quantity of the battery cell to be measured based on the first heat quantity and the second heat quantity.

[0063] Optionally, S103 specifically includes:

[0064] Using the fifth formula: calculate the proportion of the reversible heat quantity of the battery cell to be measured, where Q Char is the first heat quantity, Q Dis is the second heat quantity, and η rev (t) is the proportion of the reversible heat quantity of the battery cell to be measured.

[0065] Specifically, the proportion of the reversible heat quantity refers to the proportion of half of the absolute value of the difference between the heat quantities generated during the charging and discharging processes of the battery cell to be measured in the total heat quantity, Figure 3 is the schematic diagram of the proportion division of the charging and discharging energy of the battery cell to be measured provided by the embodiment of the present invention. As Figure 3 shown, the second region above the charging process curve is the heat loss Q Char during the charging process, that is, the first heat quantity, and the third region below the discharging process curve is the heat loss Q Dis during the discharging process, that is, the second heat quantity. The proportion of the reversible heat quantity η rev (t) is

[0066] S104, determine whether there is an aging problem with the battery cell to be measured based on the proportion of the reversible heat quantity.

[0067] Optionally, S104 specifically includes: comparing the proportion of reversible heat with a preset empirical heat threshold; if the proportion of reversible heat is less than the preset empirical heat threshold, there is an aging problem with the battery cell under test.

[0068] Specifically, after calculating the proportion of reversible heat η rev (t), it is only necessary to compare the proportion of reversible heat η rev (t) with the preset empirical heat threshold η rev (t)0. Since a certain reasonable proportion of reversible heat needs to exist, when η rev (t) < η rev (t)0, it indicates that the proportion of reversible heat of the battery cell under test does not reach the required value, and there is an aging problem with the battery cell under test. When η rev (t) ≥ η rev (t)0, that is, when the proportion of reversible heat exceeds the preset empirical heat threshold, it indicates that the battery cell under test is in a normal working state and there is no aging problem.

[0069] Based on the above technical solutions, Figure 4 is a flowchart of another method for detecting the aging of a battery cell provided by an embodiment of the present invention. As Figure 4 shown, S102 specifically includes:

[0070] S401, determining the specific heat capacity mass coefficient of the battery cell under test based on the mass and the comprehensive specific heat capacity of the battery cell under test.

[0071] Specifically, since the battery cell under test is made of multiple materials, the specific heat capacity of each material is different, and the mass used for each material is also different. Therefore, it is necessary to first calculate the specific heat capacity mass coefficient of the battery cell under test according to the mass of different materials used in the battery cell under test and the specific heat capacity of different materials.

[0072] Optionally, S401 specifically includes: based on the mass and the comprehensive specific heat capacity of the battery cell under test, using the first formula:

[0073]

[0074] to determine the specific heat capacity mass coefficient of the battery cell under test; where CM Cell (t) is the specific heat capacity mass coefficient at time t, C j (t) is the comprehensive specific heat capacity at time t, M j (t) is the mass of different materials in the battery cell under test at time t, and j is the number of material types of the battery cell under test.

[0075] Exemplarily, assuming that a certain battery cell under test is made of three materials, the specific heat capacity mass coefficient of the battery cell under test is: CM Cell(t) = C1(t)M1(t) + C2(t)M2(t) + C3(t)M3(t). During the calculation process, as the battery cell under test is used, different degrees of loss will occur. For the accuracy of the calculation, the mass and the comprehensive specific heat capacity used need to be obtained at the same moment. Therefore, the mass and specific heat capacity of each material of the battery cell under test are all obtained at time t.

[0076] S402. Calculate the heat of each charge-discharge stage by using the specific heat capacity mass coefficient and the temperature of the battery cell under test.

[0077] Specifically, for more accurate calculation, calculate the heat of each charge-discharge stage by using the calculated specific heat capacity mass coefficient.

[0078] Optionally, S402 specifically includes: using the specific heat capacity mass coefficient and the temperature of the battery cell under test, according to the second formula:

[0079]

[0080] Calculate the heat of each charge-discharge stage respectively; where, ΔQ(t n ) is the heat of each charge-discharge stage, CM Cell (t) is the specific heat capacity mass coefficient at time t, ΔT(t n ) is the temperature of the battery cell under test at time t, Δt n is the duration of each charge-discharge stage, and n is the number of time periods divided in a charge stage or a discharge stage.

[0081] Specifically, divide a charge stage or a discharge stage into n segments, each segment with a duration of Δt n , and the temperature change within this segment is ΔT(t n ). Then, by using the specific heat capacity mass coefficient CM Cell (t n ), the heat generated within the n time periods in a charge stage or a discharge stage can be calculated, and the sum is the heat ΔQ(t n ) of each charge-discharge stage.

[0082] S403. Add up the calculated heat of each charge-discharge stage respectively to obtain the first heat and the second heat.

[0083] Optionally, S403 specifically includes:

[0084] Use the third formula:

[0085]

[0086] Calculate the first heat, where, Q Char is the first heat, ΔQ(t Char-i) is the heat of the battery cell under test calculated according to the second formula, and Char-i is the number of marked time periods in each charging stage of the battery cell under test;

[0087] Using the fourth formula:

[0088]

[0089] Calculate the second heat, where Q Dis is the second heat, and ΔQ(t Dis-i ) is the heat of the battery cell under test calculated according to the second formula in each discharge stage, and Dis-i is the number of marked time periods in each discharge stage of the battery cell under test.

[0090] Specifically, after calculating the heat of each charge-discharge stage using the second formula, add up the heat of each charging stage to obtain the first heat, that is, the third formula, and add up the heat of each discharge stage to obtain the second heat, that is, the fourth formula.

[0091] Optionally, after determining the charge-discharge stages of the battery cell under test, the method for detecting the aging of the battery cell further includes: calculating the first charge and the second charge of the battery cell under test respectively, where the first charge is the total charge of the battery cell under test in each charging stage, and the second charge is the total charge of the battery cell under test in each discharge stage.

[0092] Optionally, calculating the first charge of the battery cell under test includes:

[0093] Using the sixth formula:

[0094]

[0095] Calculate the first charge of the battery cell under test, where E Char is the first charge, U(t Char-i ) is the voltage of the battery cell under test at time t Char-i , I(t Char-i ) is the current of the battery cell under test at time t Char-i , Δt Char-i is the duration of one charging stage, and Char-i is the number of marked time periods in each charging stage of the battery cell under test.

[0096] Optionally, calculating the second charge of the battery cell under test includes:

[0097] Using the seventh formula:

[0098]

[0099] Calculate the second charge of the battery cell under test, where E Dis is the second charge, U(t Dis-i ) is the voltage of the battery cell under test at time tDis-i The voltage at a moment, I(t Dis-i ) is the current of the battery cell to be measured at t Dis-i moment, Δt Dis-i is the duration of a charging stage, and Dis-i is the number of marked time periods for each discharge stage of the battery cell to be measured.

[0100] Optionally, after obtaining the first battery capacity and the second battery capacity of the battery cell to be measured, the proportion of heat consumption of the battery cell to be measured is determined by using the first battery capacity, the second battery capacity, the first heat, and the second heat: where η heat (t) is the proportion of heat consumption of the battery cell to be measured.

[0101] Specifically, as Figure 3 shown, the first region between the charging process curve and the discharging process curve reflects the energy difference E Char -E Dis . It should be noted that the preset empirical heat threshold is determined according to the proportion of heat consumption η heat (t). Since heat consumption and the proportion of power consumption involve hidden variables such as battery type and non-heat characterization attenuation, there will be time points at different aging degrees with the same proportion of reversible heat. Therefore, the preset empirical heat threshold set under the selected proportion of heat and power is more accurate.

[0102] Figure 5 is the structural diagram of a battery cell aging detection device provided by an embodiment of the present invention. As Figure 5 shown, the battery cell aging detection device specifically includes:

[0103] A stage determination unit 51, configured to determine the charging and discharging stages of the battery cell to be measured;

[0104] A first heat calculation unit 52, configured to calculate the first heat and the second heat of the battery cell to be measured based on the mass, comprehensive specific heat capacity, and temperature of the battery cell to be measured, where the first heat is the total heat generated by the battery cell to be measured in each charging stage, and the second heat is the total heat generated by the battery cell to be measured in each discharging stage;

[0105] A second heat calculation unit 53, configured to calculate the proportion of reversible heat of the battery cell to be measured based on the first heat and the second heat;

[0106] A battery cell detection unit 54, configured to determine whether there is an aging problem with the battery cell to be measured based on the proportion of reversible heat.

[0107] Optionally, the first heat calculation unit 52 includes:

[0108] A coefficient calculation subunit, configured to determine a specific heat capacity mass coefficient of a battery cell under test based on the mass and the comprehensive specific heat capacity of the battery cell under test;

[0109] A first heat calculation subunit, configured to calculate the heat of each charge and discharge stage respectively by using the specific heat capacity mass coefficient and the temperature of the battery cell under test;

[0110] A second heat calculation subunit, configured to add up the heat of each calculated charge and discharge stage respectively to obtain a first heat and a second heat.

[0111] Optionally, the coefficient calculation subunit is specifically configured to:

[0112] Based on the mass and the comprehensive specific heat capacity of the battery cell under test, use the first formula:

[0113]

[0114] Determine the specific heat capacity mass coefficient of the battery cell under test;

[0115] Wherein, CM Cell (t) is the specific heat capacity mass coefficient at time t, C j (t) is the comprehensive specific heat capacity at time t, M j (t) is the mass of different materials in the battery cell under test at time t, and j is the number of material types of the battery cell under test.

[0116] Optionally, the first heat calculation subunit is specifically configured to:

[0117] Use the specific heat capacity mass coefficient and the temperature of the battery cell under test, and according to the second formula:

[0118]

[0119] Calculate the heat of each charge and discharge stage respectively; wherein, ΔQ(t n ) is the heat of each charge and discharge stage, CM Cell (t) is the specific heat capacity mass coefficient at time t, ΔT(t n ) is the temperature of the battery cell under test at time t, Δt n is the duration of each charge and discharge stage, and n is the number of time periods divided in a charge stage or a discharge stage.

[0120] Optionally, the second heat calculation subunit is specifically configured to:

[0121] Use the third formula:

[0122]

[0123] Calculate the first heat, wherein, Q Char is the first heat, ΔQ(t Char-i) is the heat of the battery cell under test calculated according to the second formula, and Char-i is the number of marked time periods in each charging stage of the battery cell under test;

[0124] Using the fourth formula:

[0125]

[0126] Calculate the second heat, where Q Dis is the second heat, and ΔQ(t Dis-i ) is the heat of the battery cell under test calculated according to the second formula in each discharge stage, and Dis-i is the number of marked time periods in each discharge stage of the battery cell under test.

[0127] Optionally, the second heat calculation unit 53 is specifically configured to:

[0128] Using the fifth formula: Calculate the proportion of the reversible heat of the battery cell under test, where Q Char is the first heat, Q Dis is the second heat, and η rev (t) is the proportion of the reversible heat of the battery cell under test.

[0129] Optionally, the battery cell detection unit 54 is specifically configured to:

[0130] Compare the proportion of the reversible heat with a preset empirical heat threshold;

[0131] If the proportion of the reversible heat is less than the preset empirical heat threshold, there is an aging problem with the battery cell under test.

[0132] Optionally, the stage determination unit 51 is specifically configured to:

[0133] Detect the current direction of the battery cell under test within a preset time period, and determine the charge and discharge stages of the battery cell under test within the preset time period based on the detected current direction.

[0134] The battery cell aging detection device provided by the embodiments of the present invention can execute the battery cell aging detection method provided by any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method.

[0135] In the description of the embodiments of the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0136] Finally, it should be noted that the above are only the preferred embodiments of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for detecting the aging of an electric core, characterized in that, The detection method includes: Determining the charge and discharge stages of the battery cell under test during use; Calculating the first heat and the second heat of the battery cell under test based on the mass, overall specific heat capacity, and temperature of the battery cell under test, where the first heat is the total heat generated by the battery cell under test during each charging stage, and the second heat is the total heat generated by the battery cell under test during each discharging stage; Calculating the reversible heat ratio of the battery cell under test based on the first heat and the second heat; Determining whether there is an aging problem with the battery cell under test based on the reversible heat ratio; Determining whether there is an aging problem with the battery cell under test based on the reversible heat ratio includes: Comparing the reversible heat ratio with a preset empirical heat threshold; If the reversible heat ratio is less than the preset empirical heat threshold, there is an aging problem with the battery cell under test; After determining the charge and discharge stages of the battery cell under test, the detection method further includes: calculating the first charge and the second charge of the battery cell under test respectively, where the first charge is the total charge of the battery cell under test during each charging stage, and the second charge is the total charge of the battery cell under test during each discharging stage; After obtaining the first power and the second power of the battery cell to be measured, determine the heat consumption ratio of the battery cell to be measured by using the first power, the second power, the first heat, and the second heat: where η heat (t) is the heat consumption ratio of the battery cell to be measured, and the preset empirical heat threshold is determined according to the heat consumption ratio η heat (t), Q Char is the first heat, Q Dis is the second heat, E Char is the first power, E Dis is the second power.

2. The detection method for the aging of the battery cell according to claim 1, wherein, Calculating the first heat and the second heat of the battery cell under test based on the mass, overall specific heat capacity, and temperature of the battery cell under test includes: Determining the specific heat capacity-mass coefficient of the battery cell under test based on the mass and overall specific heat capacity of the battery cell under test; Calculating the heat of each charge and discharge stage respectively using the specific heat capacity-mass coefficient and the temperature of the battery cell under test; Adding up the calculated heat of each charge and discharge stage respectively to obtain the first heat and the second heat.

3. The detection method for the aging of the battery cell according to claim 2, wherein Determining the specific heat capacity-mass coefficient of the battery cell under test based on the mass and overall specific heat capacity of the battery cell under test includes: Based on the mass and the overall specific heat capacity of the battery cell under test, using the first formula: Determining the specific heat capacity-mass coefficient of the battery cell under test; Among them, CM Cell (t) is the specific heat capacity mass coefficient at time t, C j (t) is the comprehensive specific heat capacity at time t, M j (t) is the mass of different materials in the battery cell under test at time t, and j is the number of material types of the battery cell under test.

4. The method for detecting the aging of an electric core according to claim 2, wherein Calculating the heat of each charge and discharge stage respectively using the specific heat capacity-mass coefficient and the temperature of the battery cell under test includes: Using the specific heat capacity-mass coefficient and the temperature of the battery cell under test, according to the second formula: ΔQ(t n ) = ∑ n CM Cell (t n ) * ΔT(t n ) * Δt n ; Calculate the heat of each charge-discharge stage respectively; where, △Q(t n ) is the heat of each charge-discharge stage, CM Cell (t) is the specific heat capacity mass coefficient at time t, △T(t n ) is the temperature of the battery cell under test at time t, △t n is the duration of each charge-discharge stage, and n is the number of time periods divided in one charge stage or one discharge stage.

5. The method for detecting the aging of an electric cell according to claim 4, wherein Adding up the calculated heat of each charge and discharge stage respectively to obtain the first heat and the second heat includes: Using the third formula: Q Char = ∑ Char-i ΔQ(t Char-i ); Calculate the first heat, where Q Char is the first heat, and △Q(t Char-i ) is the heat of the battery cell under test at each charging stage calculated according to the second formula, and Char-i is the number of marked time periods at each charging stage of the battery cell under test; Using the fourth formula: Q Dis = ∑ Dis-i ΔQ(t Dis-i ); Calculate the second heat, where Q Dis is the second heat, △Q(t Dis-i ) is the heat of the battery cell under test calculated according to the second formula in each discharge stage, and Dis-i is the number of marked time periods in each discharge stage of the battery cell under test.

6. The detection method for the aging of the battery cell according to claim 1, wherein, Calculating the reversible heat ratio of the battery cell under test based on the first heat and the second heat includes: Using the fifth formula: Calculate the reversible heat ratio of the cell under test, where Q Char is the first heat, Q Dis is the second heat, and η rev (t) is the reversible heat ratio of the cell under test.

7. The method for detecting the aging of an electric cell according to claim 1, wherein Determining the charge and discharge stages of the battery cell under test includes: Detecting the current direction of the battery cell under test within a preset time period, and determining the charge and discharge stages of the battery cell under test within the preset time period based on the detected current direction.

8. A detection device for cell aging, characterized in that, The detection device includes: A stage determination unit for determining the charge and discharge stages of the battery cell under test during use; A first heat calculation unit for calculating the first heat and the second heat of the battery cell under test based on the mass, overall specific heat capacity, and temperature of the battery cell under test, where the first heat is the total heat generated by the battery cell under test during each charging stage, and the second heat is the total heat generated by the battery cell under test during each discharging stage; A second heat calculation unit, configured to calculate a reversible heat ratio of the battery cell under test based on the first heat and the second heat; A battery cell detection unit, configured to determine whether there is an aging problem with the battery cell under test based on the reversible heat ratio; Specifically, the battery cell detection unit is configured to: Compare the reversible heat ratio with a preset empirical heat threshold; If the reversible heat ratio is less than the preset empirical heat threshold, there is an aging problem with the battery cell under test; After the stage determination unit determines the charge and discharge stages of the battery cell under test, the detection device is further configured to: calculate a first battery charge and a second battery charge of the battery cell under test respectively, where the first battery charge is the sum of the battery charges of the battery cell under test in each charging stage, and the second battery charge is the sum of the battery charges of the battery cell under test in each discharging stage; After obtaining the first battery level and the second battery level of the battery cell to be measured, determine the heat consumption ratio of the battery cell to be measured by using the first battery level, the second battery level, the first heat quantity, and the second heat quantity: where η heat (t) is the heat consumption ratio of the battery cell to be measured, and the preset empirical heat threshold is determined according to the heat consumption ratio η heat (t), Q Char is the first heat quantity, Q Dis is the second heat quantity, E Char is the first battery level, E Dis is the second battery level.

9. The detection device for aging of the battery cell according to claim 8, wherein The first heat calculation unit includes: A coefficient calculation subunit, configured to determine a specific heat capacity mass coefficient of the battery cell under test based on the mass and the comprehensive specific heat capacity of the battery cell under test; A first heat calculation subunit, configured to calculate the heat of each charge and discharge stage respectively by using the specific heat capacity mass coefficient and the temperature of the battery cell under test; A second heat calculation subunit, configured to add up the calculated heat of each charge and discharge stage respectively to obtain the first heat and the second heat.

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