Battery health degree detection method and detection device

Abstract

The invention relates to the technical field of battery health degree detection, in particular to a battery health degree detection method and device, and the device comprises a battery parameter collection module, a battery performance calculation module, a battery health degree analysis module, a differential voltage analysis module and a user feedback module. Potential overheating or internal short circuit hidden dangers can be found in time, so that measures are taken to prevent accidents, and the service life is prolonged; meanwhile, by analyzing the health degree of the battery in combination with differential voltage, the health state of the battery can be evaluated more accurately, optimization of a charging strategy and a use mode is facilitated, excessive charging and discharging are avoided, the service life of the battery is prolonged, and user experience is improved; the positive electrode loss, the negative electrode loss and the lithium loss of the battery can be known based on differential voltage analysis, so that battery accidents caused by lithium separation and serious deterioration of a material structure are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of battery health detection, and particularly to a battery health detection method and a detection device. Background Art

[0002] With the continuous rapid development of China's new energy vehicle industry in recent years, a large number of retired electric vehicles, second-hand electric vehicles, and accident electric vehicles have emerged in the market. The power batteries they are equipped with need to be evaluated for health, and the power batteries with reuse value need to be diagnosed and repaired. By detecting and evaluating the health status of retired batteries and adopting a reasonable repair plan to functionally repair the retired batteries, the batteries can continue to serve and extend their service life, so as to achieve the purpose of improving resource utilization efficiency, alleviating resource shortage, reducing environmental pollution, promoting the development of the new energy vehicle industry, and creating sustainable economic benefits.

[0003] In the foregoing prior art, automotive batteries usually monitor voltage and current to calculate the battery health; however, only analyzing voltage and current without analyzing deep-level data such as the positive and negative electrodes of the battery cells and lithium activity will result in inaccurate calculation of the battery health, and thus it is impossible to provide the best maintenance suggestions for vehicle users. Summary of the Invention

[0004] The purpose of the present invention is to provide a battery health detection method and a detection device, which solve the problem that in the prior art, automotive batteries usually monitor voltage and current to calculate the battery health; however, only analyzing voltage and current without analyzing deep-level data such as the positive and negative electrodes of the battery cells and lithium activity will result in inaccurate calculation of the battery health, and thus it is impossible to provide the best maintenance suggestions for vehicle users.

[0005] To achieve the above purpose, the present invention provides a battery health detection device, including a battery parameter acquisition module, a battery performance calculation module, a battery health analysis module, a differential voltage analysis module, and a user feedback module. The battery parameter acquisition module, the battery performance calculation module, the battery health analysis module, the differential voltage analysis module, and the user feedback module are connected in sequence;

[0006] The battery parameter acquisition module is used to acquire the voltage, temperature, and current of the battery during the charging and discharging process of the battery to obtain acquisition data;

[0007] The battery performance calculation module is used to calculate based on the acquisition data to obtain the current internal resistance of the battery and the current charge and discharge capacity of the battery;

[0008] The battery health analysis module is used to analyze by combining the current internal resistance of the battery and the current charge and discharge capacity of the battery to obtain the battery health;

[0009] The differential voltage analysis module is used to perform differential calculation on the voltage and the current charge and discharge capacity of the battery, and draw a differential voltage curve;

[0010] The user feedback module is used to give different warnings or maintenance suggestions to the user based on the battery health and the results of the differential voltage curve.

[0011] Among them, the battery parameter acquisition module includes a charge and discharge acquisition unit and a data smoothing unit, and the charge and discharge acquisition unit is connected to the data smoothing unit;

[0012] The charge and discharge acquisition unit is used to set voltage, current and temperature sensors on the battery, so as to collect and record data in real time to obtain the acquisition data;

[0013] The data smoothing unit is used to perform data smoothing processing on the acquisition data.

[0014] Among them, the battery performance calculation module includes a load measurement unit, an open-circuit measurement unit, an internal resistance calculation unit, an internal resistance correction unit, a battery capacity calculation unit and a charge and discharge capacity correction unit, and the load measurement unit, the open-circuit measurement unit, the internal resistance calculation unit, the internal resistance correction unit, the battery capacity calculation unit and the charge and discharge capacity correction unit are connected in sequence;

[0015] The load measurement unit is used to record the load voltage and load current of the battery in the charging state;

[0016] The open-circuit measurement unit is used to disconnect the charging and record the open-circuit voltage and open-circuit current of the battery in the open-circuit state;

[0017] The internal resistance calculation unit is used to input the load voltage, load current, open-circuit voltage and open-circuit current into the calculation model to obtain the preliminary internal resistance of the battery;

[0018] The internal resistance correction unit is used to input the temperature into the internal resistance correction model to obtain the current internal resistance of the battery;

[0019] The battery capacity calculation unit is used to directly collect and obtain the current capacity of the battery by relying on sensors, and calculate the current capacity of the battery using the coulomb counting method to obtain the preliminary charge and discharge capacity;

[0020] The charge and discharge capacity correction unit is used to input the temperature into the capacity correction model to correct the preliminary charge and discharge capacity to obtain the current charge and discharge capacity of the battery.

[0021] Among them, the battery health analysis module includes a capacity analysis health unit, an internal resistance analysis health unit, and a combined analysis unit, and the capacity analysis health unit, the internal resistance analysis health unit, and the combined analysis unit are connected in sequence;

[0022] The capacity analysis health unit is used to divide the current charge and discharge capacity of the battery by the initially set capacity of the battery to obtain the capacity health;

[0023] The internal resistance analysis health unit is used to divide the current internal resistance of the battery by the initial internal resistance of the battery to obtain the internal resistance health;

[0024] The combined analysis unit is used to calculate the capacity health and the internal resistance health using the weighted average method to finally obtain the battery health.

[0025] Among them, the differential voltage analysis module includes a differential calculation unit, a curve drawing unit, and a curve analysis unit, and the differential calculation unit, the curve drawing unit, and the curve analysis unit are connected in sequence;

[0026] The differential calculation unit is used to calculate dV / dQ using the forward difference algorithm for the voltage and the current charge and discharge capacity of the battery, where dV is the voltage and dQ is the current charge and discharge capacity of the battery;

[0027] The curve drawing unit is used to plot the relationship between dV / dQ and the voltage V as a curve;

[0028] The curve analysis unit is used to analyze the peak position and peak distance of the dV / dQ curve to judge the attenuation type of the battery.

[0029] Among them, the user feedback module includes a health first-level feedback unit, a health second-level feedback unit, a health third-level feedback unit, a positive electrode peak position feedback unit, a negative electrode peak position feedback unit, a lithium-related peak position feedback unit, and a curve overall feedback unit, and the health first-level feedback unit, the health second-level feedback unit, the health third-level feedback unit, the positive electrode peak position feedback unit, the negative electrode peak position feedback unit, the lithium-related peak position feedback unit, and the curve overall feedback unit are connected in sequence;

[0030] The health first-level feedback unit is used to prompt the user that the battery capacity has decreased and the battery life has shortened when the battery health is less than 85% and greater than 65%, remind the user to pay attention to the battery usage habits to avoid further accelerating aging, and at the same time recommend that the user reduce high-rate charging and discharging;

[0031] The secondary health feedback unit is used to prompt the user that the battery capacity has decreased significantly and the user needs to consider replacing the battery when the battery health is less than 65% and greater than 50%. At the same time, it is recommended that the user avoid using the battery under high load.

[0032] The tertiary health feedback unit is used to strongly prompt the user that the battery is approaching failure and there is a safety hazard when the battery health is less than 50%. It reminds the user to immediately stop using and replace the battery. At the same time, it is recommended that the user contact the relevant technical personnel for replacement or recycling as soon as possible.

[0033] The positive peak position feedback unit is used to prompt the user that the positive electrode material of the battery is aging and the capacity is decaying rapidly after obvious changes such as the shortening of the peak distance or the shift of the peak position of the positive electrode-related peak position in the dV / dQ curve. It is recommended that the user adopt a shallow charge and discharge strategy.

[0034] The negative peak position feedback unit is used to prompt the user that the negative electrode material of the battery is aging and there may be a risk of lithium plating after obvious changes such as the left shift of the peak position or the decrease of the peak height of the negative electrode-related peak position in the dV / dQ curve. It reminds the user to pay attention to the battery heating or swelling phenomenon. At the same time, it is recommended that the user reduce the charging current and use the slow charging mode.

[0035] The lithium-related peak position feedback unit is used to prompt the user that the active lithium of the battery is lost and the capacity and internal resistance increase significantly after obvious changes such as the shift of the peak position or the decrease of the peak height of the lithium-related peak position in the dV / dQ curve. It reminds the user that the battery performance is declining rapidly. At the same time, it is recommended that the user reduce high-rate charge and discharge.

[0036] The overall curve feedback unit is used to prompt the user that the internal material structure of the battery is severely deteriorated and there is a safety hazard after significant changes in multiple peak positions and serious distortion of the curve shape in the dV / dQ curve. It is recommended to immediately stop using and contact a professional for battery recycling or disposal.

[0037] The present invention also provides a method for detecting battery health, which uses the above-mentioned battery health detection device and includes the following steps:

[0038] During the charging and discharging process of the battery, the voltage, temperature, and current of the battery are collected to obtain the collected data.

[0039] Based on the collected data, calculations are performed to obtain the current internal resistance and the current charge and discharge capacity of the battery.

[0040] The current internal resistance and the current charge and discharge capacity of the battery are combined and analyzed to obtain the battery health.

[0041] Differential calculations are performed on the voltage and the current charge and discharge capacity of the battery, and a differential voltage curve is plotted.

[0042] Based on the battery health and the results of the differential voltage curve, different warnings or maintenance suggestions are given to the user.

[0043] A battery health detection method and detection device of the present invention. The battery parameter acquisition module is used to collect the voltage, temperature, and current of the battery during the charging and discharging process of the battery to obtain acquisition data. The battery performance calculation module is used to calculate based on the acquisition data to obtain the current internal resistance of the battery and the current charge and discharge capacity of the battery. The battery health analysis module is used to analyze by combining the current internal resistance of the battery and the current charge and discharge capacity of the battery to obtain the battery health. The differential voltage analysis module is used to perform differential calculation on the voltage and the current charge and discharge capacity of the battery and draw a differential voltage curve. The user feedback module is used to give different warnings or maintenance suggestions to the user based on the battery health and the results of the differential voltage curve.

[0044] By collecting data in real time and monitoring the state of the battery, potential overheating or internal short - circuit hazards can be discovered in time, so as to take measures to prevent accidents from occurring and extend the service life. At the same time, by analyzing the battery health in combination with the differential voltage, the battery health state can be evaluated more accurately, which helps to optimize the charging strategy and usage method, avoid over - charging and over - discharging, thereby extending the service life of the battery and improving the user experience. Based on the differential voltage analysis, the positive electrode loss, negative electrode loss, and lithium loss of the battery can be understood, and then battery accidents caused by lithium deposition and serious deterioration of the material structure can be avoided. Based on the accurate health state assessment, users can obtain more reasonable maintenance suggestions, such as when to replace the battery or perform repairs, improving the convenience and satisfaction of use. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art.

[0046] Figure 1 It is the cell cycle attenuation curve of the present invention.

[0047] Figure 2 It is the cell differential voltage (dv / dq) curve of the present invention.

[0048] Figure 3 It is the schematic diagram of the battery health detection device of the present invention.

[0049] Figure 4 It is the schematic diagram of the battery parameter acquisition module of the present invention.

[0050] Figure 5 It is the schematic diagram of the battery performance calculation module of the present invention.

[0051] Figure 6It is the schematic diagram of the battery health analysis module of the present invention.

[0052] Figure 7 It is the schematic diagram of the differential voltage analysis module of the present invention.

[0053] Figure 8 It is the schematic diagram of the user feedback module of the present invention.

[0054] Figure 9 It is the step flowchart of the battery health detection method of the present invention.

[0055] 1 - Battery parameter acquisition module, 101 - Charge and discharge acquisition unit, 102 - Data smoothing unit, 2 - Battery performance calculation module, 201 - Load measurement unit, 202 - No - load measurement unit, 203 - Internal resistance calculation unit, 204 - Internal resistance correction unit, 205 - Battery capacity calculation unit, 206 - Charge and discharge capacity correction unit, 3 - Battery health analysis module, 301 - Capacity analysis health unit, 302 - Internal resistance analysis health unit, 303 - Combined analysis unit, 4 - Differential voltage analysis module, 401 - Differential calculation unit, 402 - Curve drawing unit, 403 - Curve analysis unit, 5 - User feedback module, 501 - Health first - level feedback unit, 502 - Health second - level feedback unit, 503 - Health third - level feedback unit, 504 - Positive peak position feedback unit, 505 - Negative peak position feedback unit, 506 - Lithium - related peak position feedback unit, 507 - Curve overall feedback unit. Detailed implementation manners

[0056] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0057] Please refer to Figures 1 to 8 , the present invention provides a battery health detection device, specifically including:

[0058] The battery parameter acquisition module 1 is used to acquire the voltage, temperature, and current of the battery during the charge and discharge process of the battery to obtain acquisition data;

[0059] Specifically including:

[0060] The charge and discharge acquisition unit 101 is used to set voltage, current, and temperature sensors on the battery, so as to acquire and record data in real - time to obtain acquisition data;

[0061] The parameters of the battery during charge and discharge are monitored in real - time through the sensors for subsequent calculation use.

[0062] The data smoothing unit 102 is configured to perform data smoothing processing on the acquired data.

[0063] The data is filtered, averaged, etc. by using the moving average method, so that the data is smoother and more stable, the noise of the data is removed or weakened, and the accuracy and reliability of the data are improved.

[0064] The battery performance calculation module 2 is configured to perform calculations based on the acquired data to obtain the current internal resistance of the battery and the current charge and discharge capacity of the battery;

[0065] Specifically, it includes:

[0066] The load measurement unit 201 is configured to record the load voltage and load current of the battery in the charging state;

[0067] The load voltage and load current of the battery are recorded for subsequent calculations.

[0068] The internal resistance calculation unit 203202 is configured to disconnect the charging and record the no-load voltage and no-load current of the battery in the no-load state;

[0069] The no-load voltage and no-load current of the battery are recorded for subsequent calculations

[0070] The internal resistance calculation unit is configured to input the load voltage, load current, no-load voltage and no-load current into a calculation model to obtain a preliminary internal resistance of the battery;

[0071] The calculation model is:

[0072] Where, V 1 is the load voltage, V 2 is the no-load voltage, I 1 is the load current, I 2 is the no-load current, R 1 is the preliminary internal resistance of the battery.

[0073] The internal resistance correction unit 204 is configured to input the temperature into an internal resistance correction model to obtain the current internal resistance of the battery;

[0074] The internal resistance correction model is: R 2 = R 1 × [1 + α(T - T c )]

[0075] Where, R 2 is the current internal resistance of the battery, α is the internal resistance temperature coefficient defaulted by the battery factory, Τ is the current temperature, Τ c is the reference temperature for internal resistance calculation, set at 25 °C.

[0076] The battery capacity calculation unit 205 is configured to directly collect and obtain the current battery capacity through sensors, and calculate the current battery capacity using the Coulomb counting method to obtain the preliminary charge and discharge capacity.

[0077] The charge and discharge capacity correction unit 206 is configured to input the temperature into the capacity correction model to correct the preliminary charge and discharge capacity, thereby obtaining the current charge and discharge capacity of the battery.

[0078] The capacity correction model is: C 2 = C 1 × [1 + β(T - T c )]

[0079] where C 2 is the current charge and discharge capacity of the battery, C 1 is the preliminary charge and discharge capacity, and β is the capacity temperature coefficient default at the time of battery factory shipment.

[0080] The battery health analysis module 3 is configured to analyze by combining the current internal resistance of the battery and the current charge and discharge capacity of the battery to obtain the battery health.

[0081] Specifically, it includes:

[0082] The capacity analysis health unit 301 is configured to divide the current charge and discharge capacity of the battery by the initially set capacity of the battery to obtain the capacity health.

[0083] By dividing the current charge and discharge capacity of the battery by the initially set capacity of the battery, and then multiplying the obtained data by 100, the percentage capacity health can be obtained, which represents the health of the capacity.

[0084] The internal resistance analysis health unit 302 is configured to divide the current internal resistance of the battery by the initial internal resistance of the battery to obtain the internal resistance health.

[0085] By dividing the current internal resistance of the battery by the initial internal resistance of the battery, and then multiplying the obtained data by 100, the percentage internal resistance health can be obtained, which represents the health of the internal resistance.

[0086] The combined analysis unit 303 is configured to calculate the capacity health and the internal resistance health using the weighted average method to finally obtain the battery health.

[0087] The weighted average method calculates the values of the internal resistance health and the capacity health according to different weights. For example, the ratio of the capacity health to the internal resistance health is 7:3, and finally the battery health is calculated, so as to more comprehensively and accurately evaluate the overall performance of the battery.

[0088] The differential voltage analysis module 4 is used to perform differential calculations on the voltage and the current charge and discharge capacity of the battery, and draw a differential voltage curve;

[0089] Specifically, it includes:

[0090] The differential calculation unit 401 is used to calculate the voltage and the current charge and discharge capacity of the battery using the forward difference algorithm to obtain dV / dQ, where dV is the voltage and dQ is the current charge and discharge capacity of the battery;

[0091] By performing forward difference calculations on the battery voltage and the current charge and discharge capacity of the battery, the change rates of the voltage and the current charge and discharge capacity of the battery can be obtained, which reflects the voltage and capacity fluctuations of the battery during the charge and discharge process; for subsequent curve plotting.

[0092] The curve plotting unit 402 is used to plot the relationship between dV / dQ and the voltage V as a curve;

[0093] The curve analysis unit 403 is used to analyze the peak position and peak distance of the dV / dQ curve to judge the attenuation type of the battery.

[0094] For the dV / dQ curve, in the plateau region, the change in dV is very small and approaches 0, while in the slope region, the voltage changes steeply, showing the characteristics of a "peak". Therefore, the dV / dQ peak position represents the material phase change process. Since the test current of the dV / dQ curve is very small, the power loss is ignored, so it usually reflects the loss of active substances (peak distance) related to the thermodynamics of lithium batteries and the loss of active Li (peak position);

[0095] The same conclusion can also be drawn from the dV / dQ curve. It can be seen that as the number of cycles increases, the peak position of the 1# at low SOC shifts significantly to the left, indicating that the negative active substances have been lost. To evaluate the loss of positive active substances and Li, the right endpoint of the dV / dQ curve is translated to the same position. Obviously, it is found that the peak distance of the 2# has no obvious change from 100% SOC, indicating that the positive active substances have hardly been significantly lost, while the peak distance of the 1# shifts significantly to the right from 100% SOC, indicating that there is obvious Li loss. By analyzing the degree of peak shift, the attenuation types of the cell capacity can be effectively classified and sorted.

[0096] The user feedback module 5 is used to give different warnings or maintenance suggestions to the user based on the battery health and the results of the differential voltage curve.

[0097] The first-level health feedback unit 501 is used to prompt the user that the battery capacity has decreased and the battery life has shortened when the battery health is less than 85% and greater than 65%, remind the user to pay attention to the battery usage habits to avoid further accelerating aging, and at the same time suggest that the user reduce high-rate charging and discharging;

[0098] The secondary battery health feedback unit 502 is configured to, when the battery health is less than 65% and greater than 50%, prompt the user that the battery capacity has significantly decreased and it is necessary to consider replacing the battery. At the same time, it is recommended that the user avoid high-load usage;

[0099] The tertiary battery health feedback unit 503 is configured to, when the battery health is less than 50%, strongly prompt the user that the battery is approaching failure and there is a safety hazard. Remind the user to immediately stop using and replace the battery. At the same time, it is recommended that the user contact the relevant technical personnel as soon as possible for replacement or recycling;

[0100] The positive electrode peak position feedback unit 504 is configured to, after obvious changes such as a shortening of the peak distance or a shift of the peak position occur in the positive electrode related peak positions in the dV / dQ curve, prompt the user that the positive electrode material of the battery is aging and the capacity is decaying rapidly. It is recommended that the user adopt a shallow charge and discharge strategy;

[0101] The negative electrode peak position feedback unit 505 is configured to, after obvious changes such as a left shift of the peak position or a decrease in the peak height occur in the negative electrode related peak positions in the dV / dQ curve, prompt the user that the negative electrode material of the battery is aging and there may be a risk of lithium plating. Remind the user to pay attention to the battery heating or swelling phenomenon. At the same time, it is recommended that the user reduce the charging current and use the slow charging mode;

[0102] The lithium related peak position feedback unit 506 is configured to, after obvious changes such as a shift of the peak position or a decrease in the peak height occur in the lithium related peak positions in the dV / dQ curve, prompt the user that the active lithium of the battery is lost, the capacity and internal resistance increase significantly. Remind the user that the battery performance is declining rapidly. At the same time, it is recommended that the user reduce high-rate charge and discharge;

[0103] The overall curve feedback unit 507 is configured to, when significant changes occur in multiple peak positions in the dV / dQ curve and the curve shape is severely distorted, prompt the user that the internal material structure of the battery is severely deteriorated and there is a safety hazard. It is recommended to immediately stop using and contact a professional for battery recycling or disposal.

[0104] Please refer to Figure 9 , the present invention also provides a method for detecting battery health, including the following steps:

[0105] S1: During the charging and discharging process of the battery, collect the voltage, temperature, and current of the battery to obtain the collected data;

[0106] S2: Based on the collected data, perform calculations to obtain the current internal resistance of the battery and the current charge and discharge capacity of the battery;

[0107] S3: Combine and analyze the current internal resistance of the battery and the current charge and discharge capacity of the battery to obtain the battery health;

[0108] S4: Differentiate and calculate the voltage and the current charge-discharge capacity of the battery, and plot to obtain a differential voltage curve;

[0109] S5: Based on the battery health and the results of the differential voltage curve, give different warnings or maintenance suggestions to the user.

[0110] Among them, during the charge-discharge process of the battery, the voltage, temperature, and current of the battery are collected to obtain the collected data; based on the collected data, calculations are performed to obtain the current internal resistance of the battery and the current charge-discharge capacity of the battery; the current internal resistance of the battery and the current charge-discharge capacity of the battery are combined for analysis to obtain the battery health; differentiate and calculate the voltage and the current charge-discharge capacity of the battery, and plot to obtain a differential voltage curve; based on the battery health and the results of the differential voltage curve, give different warnings or maintenance suggestions to the user.

[0111] The above-disclosed are only one or more preferred embodiments of the present application, and the scope of rights of the present application cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and equivalent changes made according to the claims of the present application still fall within the scope covered by the present application.

Claims

1. A battery health detection device, characterized in that: It includes a battery parameter acquisition module, a battery performance calculation module, a battery health analysis module, a differential voltage analysis module and a user feedback module, wherein the battery parameter acquisition module, the battery performance calculation module, the battery health analysis module, the differential voltage analysis module and the user feedback module are connected in sequence; The battery parameter acquisition module is used to collect the voltage, temperature and current of the battery during the battery charging and discharging process to obtain the collected data; The battery performance calculation module is used to calculate based on the collected data to obtain the current internal resistance of the battery and the current charge and discharge capacity of the battery; The battery health analysis module is used to analyze the current internal resistance of the battery and the current charge and discharge capacity of the battery to obtain the battery health; The differential voltage analysis module is used to perform differential calculation on the voltage and the current charge and discharge capacity of the battery, and draw a differential voltage curve; The user feedback module is used to make different warnings or maintenance suggestions to users based on the battery health and differential voltage curve results.

2. The battery health detection device according to claim 1, characterized in that: The battery parameter acquisition module includes a charge and discharge acquisition unit and a data smoothing unit, and the charge and discharge acquisition unit is connected to the data smoothing unit; The charge and discharge acquisition unit is used to set voltage, current and temperature sensors on the battery, so as to collect and record data in real time to obtain collected data; The data smoothing unit is used to perform data smoothing processing on the collected data.

3. The battery health detection device according to claim 2, characterized in that: The battery performance calculation module includes a load measurement unit, a no-load measurement unit, an internal resistance calculation unit, an internal resistance correction unit, a battery capacity calculation unit and a charge-discharge capacity correction unit, wherein the load measurement unit, the no-load measurement unit, the internal resistance calculation unit, the internal resistance correction unit, the battery capacity calculation unit and the charge-discharge capacity correction unit are connected in sequence; The load measurement unit is used to record the load voltage and load current of the battery in a charging state; The no-load measurement unit is used to disconnect charging and record the no-load voltage and no-load current of the battery in a no-load state; The internal resistance calculation unit is used to input the load voltage, load current, no-load voltage and no-load current into the calculation model to obtain the preliminary internal resistance of the battery; The internal resistance correction unit is used to input the temperature into the internal resistance correction model to obtain the current internal resistance of the battery; The battery capacity calculation unit is used to directly collect and obtain the current capacity of the battery by means of a sensor, and calculate the current capacity of the battery by means of a coulomb counting method to obtain a preliminary charge and discharge capacity; The charge and discharge capacity correction unit is used to input the temperature into a capacity correction model, correct the preliminary charge and discharge capacity, and obtain the current charge and discharge capacity of the battery.

4. The battery health detection device according to claim 3, characterized in that: The battery health analysis module includes a capacity analysis health unit, an internal resistance analysis health unit and a combined analysis unit, wherein the capacity analysis health unit, the internal resistance analysis health unit and the combined analysis unit are connected in sequence; The capacity analysis health unit is used to divide the current charge and discharge capacity of the battery by the initially set capacity of the battery to obtain the capacity health; The internal resistance analysis health unit is used to divide the current internal resistance of the battery by the initial internal resistance of the battery to obtain the internal resistance health; The combined analysis unit is used to calculate the capacity health and the internal resistance health using a weighted average method to ultimately obtain the battery health.

5. The battery health detection device according to claim 4, characterized in that: The differential voltage analysis module comprises a differential calculation unit, a curve drawing unit and a curve analysis unit, wherein the differential calculation unit, the curve drawing unit and the curve analysis unit are connected in sequence; The differential calculation unit is used to calculate the voltage and the current charge and discharge capacity of the battery using a forward difference algorithm to obtain dV / dQ, where dV is the voltage and dQ is the current charge and discharge capacity of the battery; The curve drawing unit is used to draw the relationship between dV / dQ and voltage V into a curve; The curve analysis unit is used to analyze the peak position and peak distance of the dV / dQ curve to determine the attenuation type of the battery.

6. The battery health detection device according to claim 5, characterized in that: The user feedback module includes a primary health feedback unit, a secondary health feedback unit, a tertiary health feedback unit, a positive electrode peak position feedback unit, a negative electrode peak position feedback unit, a lithium-related peak position feedback unit and a curve overall feedback unit, wherein the primary health feedback unit, the secondary health feedback unit, the tertiary health feedback unit, the positive electrode peak position feedback unit, the negative electrode peak position feedback unit, the lithium-related peak position feedback unit and the curve overall feedback unit are connected in sequence; The health level feedback unit is used to prompt the user that the battery capacity is reduced and the battery life is shortened when the battery health is less than 85% and greater than 65%, remind the user to pay attention to the battery usage habits to avoid further accelerated aging, and suggest the user to reduce high-rate charging and discharging; The health secondary feedback unit is used to remind the user that the battery capacity has dropped significantly and that the battery needs to be replaced when the battery health is less than 65% and greater than 50%, and to advise the user to avoid high-load use; The health level three feedback unit is used to strongly remind the user that the battery is close to failure and there is a safety hazard when the battery health level is less than 50%, remind the user to stop using the battery immediately and replace the battery, and suggest the user to contact relevant technicians as soon as possible for replacement or recycling; The positive electrode peak position feedback unit is used in the dV / dQ curve. When the positive electrode related peak position has a significant change in peak distance shortening or peak position shift, it prompts the user that the battery positive electrode material is aging and the capacity decays rapidly, and recommends the user to adopt a shallow charge and discharge strategy; The negative electrode peak position feedback unit is used to remind the user that the negative electrode material of the battery is aging and there may be a risk of lithium precipitation after the negative electrode related peak position in the dV / dQ curve shifts to the left or the peak height decreases significantly, reminding the user to pay attention to the heating or expansion of the battery, and at the same time suggesting that the user reduce the charging current and use the slow charging mode; The lithium-related peak position feedback unit is used in the dV / dQ curve. When the lithium-related peak position has obvious changes such as peak position shift or peak height reduction, it prompts the user that the battery has lost active lithium, and the capacity and internal resistance have increased significantly, reminding the user that the battery performance has declined rapidly, and at the same time recommending the user to reduce high-rate charging and discharging; The curve overall feedback unit is used in the dV / dQ curve. Multiple peak positions change significantly and the curve shape is seriously distorted, which prompts the user that the internal material structure of the battery is seriously deteriorated and there is a safety hazard. It is recommended to stop using the battery immediately and contact professionals for battery recycling or disposal.

7. A battery health detection method, using the battery health detection device as claimed in claim 6, characterized in that: The steps include: During the battery charging and discharging process, the voltage, temperature and current of the battery are collected to obtain the collected data; Calculate based on the collected data to obtain the current internal resistance of the battery and the current charge and discharge capacity of the battery; The current internal resistance of the battery and the current charge and discharge capacity of the battery are combined for analysis to obtain the battery health; Perform differential calculation on the voltage and the current charge and discharge capacity of the battery, and draw a differential voltage curve; Based on the battery health and differential voltage curve results, different warnings or maintenance suggestions are given to users.

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