Energy storage battery health assessment method, device, medium and equipment

Abstract

The embodiment of the present invention discloses a method for evaluating the health of an energy storage battery. The recoverable loss resistance health SOH is determined based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health. a and permanent loss resistance health SOH b ; Based on the SOH a and SOH b , establish a health formula for energy storage batteries to evaluate the health of the energy storage batteries, effectively improve the inaccurate health evaluation situation of the existing technology, and be able to promptly reflect the health status of the lithium battery and the reasons for its health deterioration.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of energy storage batteries, and in particular to a method, apparatus, medium, and equipment for evaluating the health of an energy storage battery. Background Art

[0002] Lithium batteries are currently widely used in new energy vehicles, power tools, and various energy storage applications due to their high energy density, environmental friendliness, and long lifespan. To ensure safe battery use, real-time assessment, prediction, and monitoring of lithium battery health are essential. This allows for the timely identification of deteriorating batteries, prompting alerts or removal to prevent potential safety incidents.

[0003] There are currently multiple methods for assessing the state of health (SOH), the most commonly used being the internal resistance method and the remaining capacity method. The internal resistance method measures the battery's current internal resistance by comparing it to its initial internal resistance, using the increase in internal resistance to assess the battery's health. The remaining capacity method measures the battery's current remaining capacity by comparing it to its initial capacity, using the capacity loss to assess the battery's health.

[0004] Existing technical solutions, whether it is the internal resistance method or the capacity method, or the error compensation, neural network method or big data method derived from these two basic methods, all have their limitations. The internal resistance method requires the ability to accurately and instantly measure the internal resistance of the lithium battery. However, the internal resistance of a lithium battery is a combination of multiple internal resistances, making it difficult to measure. Therefore, the accuracy of the internal resistance method is low. The accuracy of the residual capacity method also depends on the measurement of capacity. The capacity of a lithium battery is affected by many factors, such as charge and discharge rate, temperature, current SOH, etc., and the capacity of the lithium battery itself also has a certain degree of randomness, which can easily cause large random deviations and produce false alarms and judgments. Summary of the Invention

[0005] Embodiments of the present invention provide a method, apparatus, medium, and device for evaluating the health of a storage battery, which can promptly reflect the health status of a lithium battery and the reasons for its deterioration, and provide more timely and accurate risk prediction.

[0006] In a first aspect, an embodiment of the present invention provides a method for evaluating the health of an energy storage battery, the method comprising:

[0007] According to the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health, the recoverable loss resistance health SOH is determined a and permanent loss resistance health SOH b ;

[0008] Based on the SOH a and SOH b, establish a health formula for the energy storage battery to evaluate the health of the energy storage battery, wherein the health formula for the energy storage battery is:

[0009] SOH=μ1SOH a +μ2SOH b (1);

[0010] Among them, μ1 and μ2 are proportional coefficients.

[0011] Optionally, the SOH is determined based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health. a and SOH b The calculation formula is:

[0012] SOH b =R 永久损失(n) / R 永久损失(EOL) (2);

[0013] SOH a =R 可恢复损失(n) / R 可恢复损失(EOL) (3);

[0014] Among them, R 永久损失(n) is the internal resistance of the nth capacity loss, R 永久损失(EOL) is the internal resistance of permanent loss at termination, R 可恢复损失(EOL) is the internal resistance that can recover the capacity loss at termination, R 可恢复损失(n) is the internal resistance for the nth recoverable capacity loss.

[0015] Optional, R 永久损失(n) and R 可恢复损失(n) The charge and discharge cycle is n times, calculated based on the data results of the DC internal resistance test and the AC impedance test and the following formula:

[0016] △R DC =R 永久损失 +R 可恢复损失 (4);

[0017] R 永久损失 =(△R s +α△R ct ) / (△R s +△R ct +△R w )*△R DC (5);

[0018] R 可恢复损失 =(△R w +β△R ct ) / (△R s +△R ct +△R w)*△R DC (6);

[0019] Among them, △R DC The increase in DC internal resistance DCR, △R s is the added value of the ohmic internal resistance, △R ct is the added value of electrochemical internal resistance, and △R w is the increase in diffusion resistance, where α+β=1, α and β are △R ct Distribution coefficient between permanent loss of internal resistance and recoverable loss of internal resistance.

[0020] Optionally, the data result processing process of the DC internal resistance test is as follows: obtaining DC resistance DCR data of different states of charge SOC under charge and discharge conditions, and constructing a DCR-SOC fitting curve; obtaining DCR data according to the DCR-SOC fitting curve and normalizing it as the initial DCR value; obtaining DCR cycle values of different SOCs under n cycles of charge and discharge conditions, and determining ΔR based on the initial DCR value. DC .

[0021] Optionally, the data result processing process of the AC impedance test is: under the charge and discharge state, the ohmic internal resistance R of different SOC is obtained by AC impedance method (such as EIS test method). s , electrochemical internal resistance R ct And the diffusion resistance R w The fitting curve is obtained and the corresponding R s Initial value, R ct Initial value and R w Initial value; obtain R of different SOC under n cycles of charge and discharge s Cycle value, R ct Cycle value and R w cycle value, and determine △R based on its corresponding initial value s , △R ct and △R w .

[0022] Optionally, the method further includes: re-charging and discharging the energy storage battery according to a preset cycle to correct the DCR value under different SOC conditions.

[0023] Optionally, the re-charging and discharging operations on the energy storage battery to correct the DCR value under different SOC conditions include: charging and discharging the energy storage battery to different SOCs according to a preset rate; after standing for a preset time, calculating the DCR value under the current SOC condition and using it as the SOC correction value.

[0024] In a second aspect, an embodiment of the present invention provides a device for evaluating the health of an energy storage battery, the device comprising:

[0025] The loss resistance health determination module is used to determine the recoverable loss resistance health SOH based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health a and permanent loss resistance health SOH b ;

[0026] Health assessment module for a and SOH b , establish a health formula for the energy storage battery to evaluate the health of the energy storage battery, wherein the health formula for the energy storage battery is:

[0027] SOH=μ1SOH a +μ2SOH b (1);

[0028] Among them, μ1 and μ2 are proportional coefficients.

[0029] Optionally, in the loss resistor health determination module, determine SOH a and SOH b The calculation formula is:

[0030] SOH b =R 永久损失(n) / R 永久损失(EOL) (2);

[0031] SOH a =R 可恢复损失(n) / R 可恢复损失(EOL) (3);

[0032] Among them, R 永久损失(n) is the internal resistance of the nth capacity loss, R 永久损失(EOL) is the internal resistance of permanent loss at termination, R 可恢复损失(EOL) is the internal resistance that can recover the capacity loss at termination, R 可恢复损失(n) is the internal resistance for the nth recoverable capacity loss.

[0033] Optional, R 永久损失(n) and R 可恢复损失(n) The charge and discharge cycle is n times, calculated based on the data results of the DC internal resistance test and the AC impedance test and the following formula:

[0034] △R DC =R 永久损失 +R 可恢复损失 (4);

[0035] R 永久损失 =(△R s+α△R ct ) / (△R s +△R ct +△R w )*△R DC (5);

[0036] R 可恢复损失 =(△R w +β△R ct ) / (△R s +△R ct +△R w )*△R DC (6);

[0037] Among them, △R DC The increase in DC internal resistance DCR, △R s is the added value of the ohmic internal resistance, △R ct is the added value of electrochemical internal resistance, and △R w is the increase in diffusion resistance, where α+β=1, α and β are △R ct Distribution coefficient between permanent loss of internal resistance and recoverable loss of internal resistance.

[0038] Optionally, the data result processing process of the DC internal resistance test in the loss resistance health determination module is as follows: obtaining DC resistance DCR data of different states of charge SOC under charge and discharge conditions, and constructing a DCR-SOC fitting curve; obtaining DCR data according to the DCR-SOC fitting curve and normalizing it as the DCR initial value; obtaining DCR cycle values of different SOCs under n cycles of charge and discharge conditions, and determining ΔR based on the DCR initial value. DC .

[0039] Optionally, the data processing process of the AC impedance test in the loss resistance health determination module is as follows: Under the charge and discharge states, the ohmic internal resistance R of different SOCs is obtained by the AC impedance method. s , electrochemical internal resistance R ct And the diffusion resistance R w The fitting curve is obtained and the corresponding R s Initial value, R ct Initial value and R w Initial value; obtain R of different SOC under n cycles of charge and discharge s Cycle value, R ct Cycle value and R w cycle value, and determine △R based on its corresponding initial value s , △R ct and △R w .

[0040] Optionally, the device further includes:

[0041] The correction module is used to re-charge and discharge the energy storage battery according to a preset cycle to correct the DCR value under different SOC conditions.

[0042] Optionally, the correction module is specifically configured to:

[0043] The energy storage battery is charged and discharged to different SOCs according to a preset rate; after standing for a preset time, the DCR value under the current SOC is calculated and used as the SOC correction value.

[0044] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for evaluating the health of an energy storage battery.

[0045] In a fourth aspect, an embodiment of the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the energy storage battery health assessment method as described above when executing the computer program.

[0046] The embodiment of the present invention determines the recoverable loss resistance health SOH based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health. a and permanent loss resistance health SOH b ; Based on the SOH a and SOH b , establish a health formula for energy storage batteries to evaluate the health of the energy storage batteries, effectively improve the inaccurate health evaluation situation of the existing technology, and be able to promptly reflect the health status of the lithium battery and the reasons for its health deterioration. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flow chart of a method for evaluating the health of an energy storage battery provided in Example 1 of the present invention;

[0048] Figure 2 This is a schematic diagram of a DCR-SOC fitting curve obtained by using an interpolation method in a method for evaluating the health of an energy storage battery provided in the second embodiment of the present invention;

[0049] Figure 3 This is a schematic structural diagram of a device for evaluating the health of an energy storage battery provided in a third embodiment of the present invention;

[0050] Figure 4 This is a structural diagram of an electronic device provided in Example 5 of the present invention. DETAILED DESCRIPTION

[0051] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0052] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the steps as sequential processes, many of the steps can be implemented in parallel, concurrently, or simultaneously. In addition, the order of the steps can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0053] First of all, the implementation of this solution can be based on the following premises:

[0054] The network module distinguishes between the server and the client.

[0055] The application is divided into server and client. However, unlike most applications that need to distinguish between server and client, this product does not want to set up a separate computer as a server for reasons such as cost control, freedom of program startup, and convenience.

[0056] Therefore, after the program is started, it will first parse the information recorded in the configuration file through the network module to determine whether it is a server. If it is a server, it is both a server and a client, and other computers are clients.

[0057] Determine the network transmission communication protocol.

[0058] Based on the network environment in which this program operates, UDP is selected as the underlying network transmission communication protocol. However, considering that UDP is an unreliable protocol, that is, network data packet loss and unreliable ordering may occur, the UDP+KCP solution is selected to achieve reliable UDP transmission. In addition, during the user login preparation phase, TCP is used as the network transmission communication protocol to ensure the reliability of user login.

[0059] Specifies parameter settings in the synchronization logic.

[0060] Specifies the parameters required in the synchronization logic so that these pre-set parameters can be easily used in the synchronization algorithm process. Specifically, they include: server IP address, server network port, local client IP address, server frame interval, heartbeat packet frame interval, the time it takes for the server to determine that the client has timed out and disconnected, the time it takes for the client to determine that the server has timed out and disconnected, and the client frame rate multiplier.

[0061] Specifies the synchronous message data protocol.

[0062] First, you need to specify the message type, including: synchronization preparation, synchronization start, tracking data, synchronization exit, heartbeat packet, and custom message. Next, you need to specify the message data, including: message type, source player ID, target player ID, tracking data, ping value timestamp, and custom message. Finally, you need to specify the upstream protocol for data sent by the client to the server, and the downstream protocol for data sent by the server to the client. The upstream protocol includes: session ID and message list, and the downstream protocol includes: frame ID and message list.

[0063] Example 1

[0064] Figure 1 This is a flow chart of a method for evaluating the health of an energy storage battery provided in Example 1 of the present invention. This method can be performed by the energy storage battery health evaluation device provided in an embodiment of the present invention, which can be implemented in software and / or hardware. The method specifically includes:

[0065] S110, determine the recoverable loss resistance health SOH based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health a and permanent loss resistance health SOH b .

[0066] Specifically, this embodiment divides battery capacity loss into two parts: recoverable capacity loss and permanent capacity loss (irrecoverable capacity loss). Permanent capacity loss is primarily caused by changes in material structure, growth of the SEI film, side reactions, and a decrease in material vacancies. Recoverable capacity loss is primarily caused by polarization and reversible lithium.

[0067] Therefore, this embodiment establishes a recoverable loss resistance health SOH a and the recoverable loss resistance R 可恢复损失(n) , and permanent loss resistance health SOH b With R 永久损失(n) The function relationship of the recoverable loss resistor health SOH is used to determine the recoverable loss resistor health SOH a and permanent loss resistance health SOH b .

[0068] S120, based on the SOH a and SOH b , establish a health formula for the energy storage battery to evaluate the health of the energy storage battery.

[0069] The health formula of the energy storage battery is:

[0070] SOH=μ1SOH a +μ2SOH b (1); where μ1 and μ2 are proportional coefficients.

[0071] Therefore, in the embodiment of the present invention, when the energy storage battery is stopped at any SOC during use, the current SOH can be obtained. a and SOH b The proportional coefficient, SOH represents the health of the battery, the highest is 100%, the lower the health, the less healthy.

[0072] In this embodiment, the SOH is determined based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health. a and SOH b The calculation formula is:

[0073] SOH b =R 永久损失(n) / R 永久损失(EOL) (2);

[0074] SOH a =R 可恢复损失(n) / R 可恢复损失(EOL) (3);

[0075] Among them, R 永久损失(n) is the internal resistance of the nth capacity loss, R 永久损失(EOL) is the internal resistance of permanent loss at termination, R 可恢复损失(EOL) is the internal resistance that can recover the capacity loss at termination, R 可恢复损失(n) is the internal resistance for the nth recoverable capacity loss.

[0076] Among them, R (EOL) It refers to the internal resistance at the end of life, which can be obtained according to the current definition of SOH. The definition formula is: SOH=(R (EOL) -R n ) / (R (EOL) -R new )(7), where R n is the resistance in the current charge and discharge state; R new is the initial resistance.

[0077] In the embodiment of the present invention, R 永久损失(n) and R 可恢复损失(n) The charge and discharge cycle is n times, calculated based on the data results of the DC internal resistance test and the AC impedance test and the following formula:

[0078] △R DC =R 永久损失 +R 可恢复损失 (4);

[0079] R 永久损失 =(△R s +α△R ct ) / (△R s +△R ct +△R w )*△R DC (5);

[0080] R 可恢复损失 =(△R w +β△R ct ) / (△R s +△R ct +△R w )*△R DC (6);

[0081] Among them, △R DC The increase in DC internal resistance DCR, △R s is the added value of the ohmic internal resistance, △R ct is the added value of electrochemical internal resistance, and △R w is the increase in diffusion resistance, where α+β=1, α and β are △R ct Distribution coefficient between permanent loss of internal resistance and recoverable loss of internal resistance.

[0082] Therefore, this embodiment divides the total DCR increase into two parts: permanent R loss and recoverable R loss. The proportion of permanent R loss and recoverable R loss to capacity loss is established based on the DC internal resistance and AC impedance measurement results.

[0083] In an embodiment of the present invention, the data result processing process of the DC internal resistance test is as follows: obtaining DC resistance DCR data of different states of charge SOC under charge and discharge conditions, and constructing a DCR-SOC fitting curve; obtaining DCR data according to the DCR-SOC fitting curve and normalizing it as the DCR initial value; obtaining DCR cycle values of different SOCs under n cycles of charge and discharge conditions, and determining ΔR based on the DCR initial value. DC .

[0084] Specifically, this embodiment tests the DCR (DC internal resistance) of lithium batteries at different SOCs (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%) at 25±3°C according to the HPPC test method, and then uses the interpolation method to obtain the adjacent DCR-SOC fitting curves. The obtained fitting curve data is then stored and called in the evaluation device, and the DCR of the charging state and the discharge state are normalized as the initial DCR value. Finally, after a certain number of charge and discharge cycles, the DCR cycle values at the above-mentioned different SOCs (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%) are measured respectively, and the DCR increase value △R is determined based on the DCR initial value. DC .

[0085] In the embodiment of the present invention, the data result processing process of the AC impedance test is as follows: Under the charge and discharge states, the ohmic internal resistance R of different SOC is obtained by the AC impedance method. s , electrochemical internal resistance R ct And the diffusion resistance R w The fitting curve is obtained and the corresponding R s Initial value, R ct Initial value and R w Initial value; obtain R of different SOC under n cycles of charge and discharge s Cycle value, R ct Cycle value and R w cycle value, and determine △R based on its corresponding initial value s , △R ct and △R w .

[0086] Specifically, this embodiment adopts the AC impedance method, first determining the fitting under SOC of 0% and 100%, then obtaining the internal resistance under the remaining SOC (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%), and fitting to obtain the ohmic internal resistance R s Initial value, electrochemical internal resistance R ct Initial value and diffusion resistance R w Initial value. Then, obtain R of different SOC in n cycles of charge and discharge. s Cycle value, R ct Cycle value and R w cycle value, and determine △R based on its corresponding initial value s , △R ct and △R w .

[0087] In an embodiment of the present invention, the method further includes: re-charging and discharging the energy storage battery according to a preset cycle to correct the DCR value under different SOC conditions.

[0088] The preset period may be a value set by the staff according to actual conditions, so that corrections will be made after each period of use to improve the accuracy of the data.

[0089] In an embodiment of the present invention, re-charging and discharging the energy storage battery to correct the DCR value under different SOC conditions includes: charging and discharging the energy storage battery to different SOCs according to a preset rate; and after standing for a preset time, calculating the DCR value under the current SOC condition and using it as the SOC correction value.

[0090] Among them, the preset ratio and preset time are also values set by the staff according to actual conditions.

[0091] Specifically, after a period of use, the lithium battery enters the capacity correction process. Two processes are used: charging and discharging. The charging process:

[0092] 1. Discharge the lithium battery capacity to below 5%, then charge it to 10% SOC at a specific rate, and then let it stand for more than 30 minutes. Calculate the DCR at this time c (10% SOC);

[0093] 2. Then charge it from 10% SOC to 20% SOC at a specific rate, then let it sit for more than 30 minutes and calculate the DCR at this time c (20% SOC);

[0094] 3. Continue in this way until the battery is charged to 90% SOC and calculate the DCR c (90% SOC) ended.

[0095] Discharge procedure:

[0096] 1. Charge the lithium battery to more than 90% capacity, then discharge it to 90% SOC at a specific rate, and then let it stand for more than 30 minutes to calculate the DCR d (90% SOC);

[0097] 2. Then discharge it from 90% SOC to 80% SOC at a specific rate, then let it rest for more than 30 minutes to calculate the DCR d (80% SOC);

[0098] 3. Continue in this way until the battery is discharged to 10% SOC and the DCR is calculated. d (10% SOC).

[0099] The embodiment of the present invention determines the recoverable loss resistance health SOH based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health. a and permanent loss resistance health SOH b ; Based on the SOH a and SOH b , establish a health formula for energy storage batteries to evaluate the health of the energy storage batteries, effectively improve the inaccurate health evaluation situation of the existing technology, and be able to promptly reflect the health status of the lithium battery and the reasons for its health deterioration.

[0100] Example 2

[0101] For example, the battery used in this embodiment is a lithium iron phosphate square aluminum shell battery. Figure 2 This is a schematic diagram of a DCR-SOC fitting curve obtained by using an interpolation method in a method for evaluating the health of an energy storage battery provided in the second embodiment of the present invention.

[0102] 1) First, the DCR (direct current internal resistance) of lithium batteries at different charge and discharge states (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%) was measured at 25±3°C according to the HPPC test method. Interpolation was then used to obtain fitting curves between adjacent DCR and SOC values.

[0103] 2) The internal resistance at SOC of 0% and 100% is obtained by fitting using the AC impedance method.

[0104] 3) Then use the AC impedance method to obtain the internal resistance at other SOCs (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%), and fit to obtain the ohmic internal resistance R s , electrochemical internal resistance R ct And the diffusion resistance R w .

[0105] 4) The obtained data is stored in an evaluation device, and the DCR of the charging state and the discharging state are normalized.

[0106] 5) After 10 cycles, the DCR increase values at different SOCs (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%) and the ohmic internal resistance R are measured. s , electrochemical internal resistance R ct And the diffusion resistance R w The increase in value is recorded as △R DC , △R s , △R ct , △Rw .

[0107] 6) Divide the total DCR increase into two parts: R permanent loss and R recoverable loss. Based on the DC internal resistance and AC impedance results, establish the proportion of R permanent loss and R recoverable loss to capacity loss respectively. The formula is as follows: △R DC =R 永久损失 +R 可恢复损失

[0108] R 永久损失 =(△Rs+α△Rct) / (△Rs+△Rct+△Rw)*△R DC

[0109] R 可恢复损失 =(△Rw+β△Rct) / (△Rs+△Rct+△Rw)*△R DC

[0110] Among them, α+β=1, α=0.45, β=0.55,

[0111] Among them, the values of α and β are set according to the test value analysis of the battery used, and different batteries may have different

[0112] 7) The evaluation of lithium battery health status is divided into two parts: SOH a =R 永久损失(n) / R 永久损失(EOL) ,SOH b =R 可恢复损失(n) / R 可恢复损失(EOL) , where R 永久损失(EOL) is the internal resistance of permanent loss at termination, R 永久损失(n) is the internal resistance of the nth capacity loss, and similarly R 可恢复损失(EOL) is the internal resistance that can recover the capacity loss at termination, R 永久损失(n) is the internal resistance for the nth recoverable capacity loss.

[0113] 8) Therefore, the health status of the lithium battery is expressed as SOH = μ1SOH a +μ2SOH b

[0114] In the lithium-ion battery sector, health status assessment is becoming increasingly important, enabling early prediction of potential risks, early warning, and the implementation of response strategies. However, both internal resistance and capacity loss methods are difficult to accurately assess, are affected by the battery's health status, and exhibit a lag, significantly reducing the effectiveness of early warnings.

[0115] A lithium battery health status assessment method and device, as provided by embodiments of the present invention, can effectively address the aforementioned issues. This method splits the lost capacity into recoverable and permanent capacity, each corresponding to a different portion or stage of the lithium battery's internal resistance. The health status is then represented as a combined function of the recoverable and permanent capacity internal resistance portions. This avoids the impact of inaccurate internal resistance measurement or randomness of capacity loss on the accuracy of the health status, and can promptly reflect the health status of the lithium battery and the causes of its deterioration, providing more accurate and timely risk prediction.

[0116] Example 3

[0117] Figure 3 : This is a schematic diagram of a device for evaluating the health of an energy storage battery provided by an embodiment of the present invention. The device specifically includes:

[0118] The loss resistor health determination module 310 is used to determine the recoverable loss resistor health SOH based on the functional relationship between the recoverable loss resistor and the permanent loss resistor and their corresponding loss health. a and permanent loss resistance health SOH b ;

[0119] Health evaluation module 320 is used to evaluate the health of a and SOH b , establish a health formula for the energy storage battery to evaluate the health of the energy storage battery, wherein the health formula for the energy storage battery is:

[0120] SOH=μ1SOH a +μ2SOH b (1);

[0121] Among them, μ1 and μ2 are proportional coefficients.

[0122] Optionally, in the loss resistor health determination module 310, the SOH is determined a and SOH b The calculation formula is:

[0123] SOH b =R 永久损失(n) / R 永久损失(EOL) (2);

[0124] SOH a =R 可恢复损失(n) / R 可恢复损失(EOL) (3);

[0125] Among them, R 永久损失(n) is the internal resistance of the nth capacity loss, R 永久损失(EOL) is the internal resistance of permanent loss at termination, R 可恢复损失(EOL)is the internal resistance that can recover the capacity loss at termination, R 可恢复损失(n) is the internal resistance for the nth recoverable capacity loss.

[0126] Optional, R 永久损失(n) and R 可恢复损失(n) The charge and discharge cycle is n times, calculated based on the data results of the DC internal resistance test and the AC impedance test and the following formula:

[0127] △R DC =R 永久损失 +R 可恢复损失 (4);

[0128] R 永久损失 =(△R s +α△R ct ) / (△R s +△R ct +△R w )*△R DC (5);

[0129] R 可恢复损失 =(△R w +β△R ct ) / (△R s +△R ct +△R w )*△R DC (6);

[0130] Among them, △R DC The increase in DC internal resistance DCR, △R s is the added value of the ohmic internal resistance, △R ct is the added value of electrochemical internal resistance, and △R w Add value for diffusion resistance.

[0131] Optionally, the data result processing process of the DC internal resistance test in the loss resistor health determination module 310 is as follows:

[0132] Under the charge and discharge conditions, the DC resistance (DCR) data of different states of charge (SOC) are obtained, and the DCR-SOC fitting curve is constructed.

[0133] According to the DCR-SOC fitting curve, DCR data is obtained and normalized as the initial DCR value;

[0134] Obtain the DCR cycle value of different SOC under n cycles of charge and discharge, and determine ΔR based on the initial DCR value. DC .

[0135] Optionally, the data result processing process of the AC impedance test in the loss resistance health determination module 310 is as follows:

[0136] Under the charge and discharge states, the ohmic internal resistance R of different SOC is obtained by AC impedance method. s , electrochemical internal resistance R ct And the diffusion resistance R w The fitting curve is obtained and the corresponding R s Initial value, R ct Initial value and R w Initial value;

[0137] Obtain R at different SOC under n cycles of charge and discharge s Cycle value, R ct Cycle value and R w cycle value, and determine △R based on its corresponding initial value s , △R ct and △R w .

[0138] Optionally, the device further includes:

[0139] The correction module is used to re-charge and discharge the energy storage battery according to a preset cycle to correct the DCR value under different SOC conditions.

[0140] Optionally, the correction module is specifically configured to:

[0141] The energy storage battery is charged and discharged to different SOCs according to a preset rate; after standing for a preset time, the DCR value under the current SOC is calculated and used as the SOC correction value.

[0142] Example 4

[0143] The present application also provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform:

[0144] According to the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health, the recoverable loss resistance health SOH is determined a and permanent loss resistance health SOH b ;

[0145] Based on the SOH a and SOH b , establish a health formula for the energy storage battery to evaluate the health of the energy storage battery.

[0146] Storage medium - any of various types of memory devices or storage devices. The term "storage medium" is intended to include: installation media, such as CD-ROMs, floppy disks, or tape drives; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory, such as flash memory, magnetic media (such as hard disks or optical storage); registers or other similar types of memory elements, etc. Storage media may also include other types of memory or combinations thereof. In addition, the storage medium may be located in the computer system in which the program is executed, or may be located in a different second computer system that is connected to the computer system via a network (such as the Internet). The second computer system may provide program instructions to the computer for execution. The term "storage medium" may include two or more storage media that may reside in different locations (e.g., in different computer systems connected via a network). The storage medium may store program instructions (e.g., embodied as a computer program) that can be executed by one or more processors.

[0147] Of course, the storage medium containing computer-executable instructions provided in an embodiment of the present application is not limited to the energy storage battery health assessment operation described above, and can also execute related operations in the energy storage battery health assessment method provided in any embodiment of the present application.

[0148] Example 5

[0149] An embodiment of the present application provides an electronic device, into which the energy storage battery health assessment device provided in the embodiment of the present application can be integrated. Figure 4 This is a schematic diagram of the structure of an electronic device provided in Example 5 of this application. Figure 4 As shown, this embodiment provides an electronic device 400, which includes: one or more processors 420; a storage device 410 for storing one or more programs. When the one or more programs are executed by the one or more processors 420, the one or more processors 420 implement:

[0150] According to the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health, the recoverable loss resistance health SOH is determined a and permanent loss resistance health SOH b ;

[0151] Based on the SOH a and SOH b , establish a health formula for the energy storage battery to evaluate the health of the energy storage battery.

[0152] like Figure 4As shown, the electronic device 400 includes a processor 420, a storage device 410, an input device 430, and an output device 440; the number of processors 420 in the electronic device can be one or more. Figure 4 In the figure, a processor 420 is used as an example; the processor 420, the storage device 410, the input device 430 and the output device 440 in the electronic device can be connected via a bus or other means. Figure 4 The connection via bus 450 is taken as an example.

[0153] The storage device 410 is a computer-readable storage medium that can be used to store software programs, computer-executable programs, and module units, such as program instructions corresponding to the energy storage battery health assessment method in the embodiment of the present application.

[0154] The storage device 410 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function; the data storage area may store data created based on the use of the terminal, etc. Furthermore, the storage device 410 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state memory device. In some instances, the storage device 410 may further include a memory remotely located relative to the processor 420, and such remote memory may be connected via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0155] The input device 430 may be used to receive input numbers, character information or voice information, and generate key signal input related to user settings and function control of the electronic device. The output device 440 may include a display screen, a speaker and other devices.

[0156] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for evaluating the health of an energy storage battery, characterized in that: include: According to the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health, the recoverable loss resistance health SOH is determined a and permanent loss resistance health SOH b ; Based on the SOH a and SOH b , establish a health formula for the energy storage battery to evaluate the health of the energy storage battery, wherein the health formula for the energy storage battery is: SOH=μ1SOH a +μ2SOH b (1); Among them, μ1 and μ2 are proportional coefficients; Determine SOH based on the functional relationship between recoverable loss resistance and permanent loss resistance and their corresponding loss health a and SOH b The calculation formula is: SOH b =R 永久损失(n) / R 永久损失(EOL) (2); SOH a =R 可恢复损失(n) / R 可恢复损失(EOL) (3); Among them, R 永久损失(n) is the internal resistance of the nth capacity loss, R 永久损失(EOL) is the internal resistance of permanent loss at termination, R 可恢复损失(EOL) is the internal resistance that can recover the capacity loss at termination, R 可恢复损失(n) is the internal resistance of the nth recoverable capacity loss; Among them, R 永久损失(n) and R 可恢复损失(n) The charge and discharge cycle is n times, calculated based on the data results of the DC internal resistance test and the AC impedance test and the following formula: △R DC =R 永久损失 +R 可恢复损失 (4); R 永久损失 =(△R s +α△R ct ) / (△R s +△R ct +△R w )*△R DC (5); R 可恢复损失 =(△R w +β△R ct ) / (△R s +△R ct +△R w )*△R DC (6); Among them, △R DC The increase in DC internal resistance DCR, △R s is the added value of the ohmic internal resistance, △R ct is the added value of electrochemical internal resistance, and △R w is the increase in diffusion resistance, where α+β=1, α and β are △R ct Distribution coefficient between permanent loss of internal resistance and recoverable loss of internal resistance.

2. The method according to claim 1, characterized in that The data result processing process of the DC internal resistance test is as follows: Under the charge and discharge conditions, the DC resistance (DCR) data of different states of charge (SOC) are obtained, and the DCR-SOC fitting curve is constructed. According to the DCR-SOC fitting curve, DCR data is obtained and normalized as the initial DCR value; Obtain the DCR cycle value of different SOC under n cycles of charge and discharge, and determine △R based on the initial DCR value DC .

3. The method according to claim 2, characterized in that The data result processing process of the AC impedance test is as follows: Under the charge and discharge states, the ohmic internal resistance R of different SOC is obtained by AC impedance method. s , electrochemical internal resistance R ct And the diffusion resistance R w The fitting curve is obtained and the corresponding R s Initial value, R ct Initial value and R w Initial value; Obtain R at different SOC under n cycles of charge and discharge s Cycle value, R ct Cycle value and R w cycle value, and determine △R based on its corresponding initial value s , △R ct and △R w .

4. The method according to claim 3, characterized in that Also includes: The energy storage battery is recharged and discharged according to a preset cycle to correct the DCR value under different SOC conditions.

5. The method according to claim 4, characterized in that The re-charging and discharging operation of the energy storage battery to correct the DCR value under different SOC conditions includes: Charging and discharging the energy storage battery to different SOCs according to a preset rate; After standing for a preset time, the DCR value under the current SOC condition is calculated and used as the SOC correction value.

6. A device for evaluating the health of an energy storage battery, characterized in that: include: The loss resistance health determination module is used to determine the recoverable loss resistance health SOH based on the functional relationship between the recoverable loss resistance and the permanent loss resistance and their corresponding loss health a and permanent loss resistance health SOH b ; Health assessment module for a and SOH b , establish a health formula for the energy storage battery to evaluate the health of the energy storage battery, wherein the health formula for the energy storage battery is: SOH=μ1SOH a +μ2SOH b (1); Among them, μ1 and μ2 are proportional coefficients; Determine SOH based on the functional relationship between recoverable loss resistance and permanent loss resistance and their corresponding loss health a and SOH b The calculation formula is: SOH b =R 永久损失(n) / R 永久损失(EOL) (2); SOH a =R 可恢复损失(n) / R 可恢复损失(EOL) (3); Among them, R 永久损失(n) is the internal resistance of the nth capacity loss, R 永久损失(EOL) is the internal resistance of permanent loss at termination, R 可恢复损失(EOL) is the internal resistance that can recover the capacity loss at termination, R 可恢复损失(n) is the internal resistance of the nth recoverable capacity loss; Among them, R 永久损失(n) and R 可恢复损失(n) The charge and discharge cycle is n times, calculated based on the data results of the DC internal resistance test and the AC impedance test and the following formula: △R DC =R 永久损失 +R 可恢复损失 (4); R 永久损失 =(△R s +α△R ct ) / (△R s +△R ct +△R w )*△R DC (5); R 可恢复损失 =(△R w +β△R ct ) / (△R s +△R ct +△R w )*△R DC (6); Among them, △R DC The increase in DC internal resistance DCR, △R s is the added value of the ohmic internal resistance, △R ct is the added value of electrochemical internal resistance, and △R w is the increase in diffusion resistance, where α+β=1, α and β are △R ct Distribution coefficient between permanent loss of internal resistance and recoverable loss of internal resistance.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the energy storage battery health assessment method according to any one of claims 1 to 5 is implemented.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein: When the processor executes the computer program, the energy storage battery health assessment method according to any one of claims 1 to 5 is implemented.

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