Electrochemical device control method, electronic device, and storage medium

Abstract

Embodiments of the present application provide an electrochemical device control method, an electronic device and a storage medium. The electrochemical device control method is used for controlling charging and discharging of a single battery cell. The electrochemical device control method comprises: obtaining a battery cell temperature parameter, the battery cell temperature parameter comprising at least one of an initial discharging temperature, a maximum discharging temperature, an initial charging temperature and a maximum charging temperature of the battery cell; if the battery cell temperature parameter satisfies a first condition, configuring the battery cell to perform at least one of reducing a charging upper limit voltage, reducing a charging current, reducing a discharging current or increasing a discharging lower limit voltage; and if the battery cell temperature parameter satisfies a second condition, issuing warning information for indicating that the battery cell is limited to be used. The present scheme can realize reasonable control of the charging and discharging process of the electrochemical device at a lower cost.

Description

Technical Field

[0001] This application relates to the field of electrical engineering technology, and in particular to an electrochemical device control method, electronic device, and storage medium. Background Technology

[0002] Lithium-ion batteries, as electrochemical devices, are widely used in consumer electronics, drones, and electric vehicles due to their advantages such as high energy density, long cycle life, high nominal voltage, low self-discharge rate, small size, and light weight. As the number of cycles increases, the state of health of lithium-ion batteries changes accordingly. Therefore, it is necessary to predict the state of health of lithium-ion batteries in order to more effectively manage their charge and discharge.

[0003] Currently, during the charging and discharging process of lithium-ion batteries, state signals such as current, voltage, and impedance of the lithium-ion battery are detected. Based on the detected state signals, the health status of the lithium-ion battery is predicted, and then the charging and discharging process of the lithium-ion battery is controlled based on the predicted health status.

[0004] However, detecting the current, voltage, impedance and other state signals of lithium-ion batteries requires the use of high-precision detection components, which are expensive. In order to predict the health status of lithium-ion batteries and then control charging and discharging based on the health status of lithium-ion batteries, detection components need to be set in each battery, which leads to the high cost of lithium-ion batteries. Summary of the Invention

[0005] In view of this, embodiments of this application provide an electrochemical device control method, electronic device, and storage medium, which can achieve reasonable control of the charging and discharging process of an electrochemical device at a lower cost.

[0006] According to a first aspect of the embodiments of this application, an electrochemical device control method is provided for controlling the charge and discharge of a single battery cell. The electrochemical device control method includes: acquiring battery cell temperature parameters, the battery cell temperature parameters including at least one of the initial discharge temperature, maximum discharge temperature, initial charging temperature, and maximum charging temperature of the battery cell; if the battery cell temperature parameters meet a first condition, configuring the battery cell to perform at least one of reducing the upper limit charging voltage, reducing the charging current, reducing the discharge current, or increasing the lower limit discharge voltage; if the battery cell temperature parameters meet a second condition, issuing a warning message to indicate a restriction on the use of the battery cell. Since the battery cell temperature parameters are related to the battery cell's capacity retention rate, and the battery cell's capacity retention rate can characterize the battery cell's health status, the charge and discharge of the battery cell can be controlled based on the battery cell temperature parameters to improve the battery cell's cycle performance, reduce safety risks, and achieve reasonable control of the battery cell's charge and discharge process. Controlling the charge and discharge process of the battery cell based on the battery cell temperature parameters only requires detecting the battery cell's temperature, eliminating the need for high-precision detection components in the battery cell, thereby enabling reasonable control of the battery cell's charge and discharge process at a lower cost.

[0007] In one possible implementation, the first condition includes: the discharge temperature growth rate of the battery cell is greater than a preset first threshold and less than a preset second threshold, and / or, the charging temperature growth rate of the battery cell is greater than a preset third threshold and less than a preset fourth threshold, wherein the first threshold is less than the second threshold and the third threshold is less than the fourth threshold; the second condition includes: the discharge temperature growth rate of the battery cell is greater than the second threshold, and / or, the charging temperature growth rate of the battery cell is greater than the fourth threshold. Since the charging temperature growth rate and discharge temperature growth rate of the battery cell are correlated with the capacity retention rate, and the capacity retention rate of the battery cell can characterize the health status of the battery cell, controlling the charging and discharging of the battery cell based on the charging temperature growth rate and discharge temperature growth rate can achieve corresponding charging and discharging strategies for the battery cell in response to different health states, thereby improving the cycle performance of the battery cell, reducing the safety risks of the battery cell, and achieving reasonable control of the charging and discharging process of the battery cell. Determining the charging temperature growth rate and discharge temperature growth rate of the battery cell only requires detecting the temperature during the charging and discharging process of the battery cell, without the need to install high-precision detection components in the battery cell, thus enabling reasonable control of the charging and discharging process of the battery cell at a lower cost.

[0008] In one possible implementation, the first condition includes: the maximum discharge temperature growth rate of the battery cell is greater than a preset fifth threshold and less than a preset sixth threshold, and / or, the maximum charging temperature growth rate of the battery cell is greater than a preset seventh threshold and less than a preset eighth threshold, wherein the fifth threshold is less than the sixth threshold and the seventh threshold is less than the eighth threshold; the second condition includes: the maximum discharge temperature growth rate of the battery cell is greater than the sixth threshold, and / or, the maximum charging temperature growth rate of the battery cell is greater than the eighth threshold. Since the battery cell capacity retention rate, the maximum discharge temperature growth rate, and the maximum charging temperature growth rate are all related to the battery cell's internal resistance, there is a correlation between the maximum discharge temperature growth rate and the maximum charging temperature growth rate and the battery cell capacity retention rate. The battery cell capacity retention rate can characterize the battery cell's health status. Therefore, by controlling the charging and discharging of the battery cell based on its maximum discharge temperature growth rate and maximum charging temperature growth rate, corresponding charging and discharging strategies can be adopted for the battery cell in response to different health states, thereby improving the battery cell's cycle performance, reducing safety risks, and achieving reasonable control of the battery cell's charging and discharging process. Determining the maximum discharge temperature growth rate and the maximum charging temperature growth rate of a battery cell only requires detecting the temperature during the charging and discharging process of the cell, without the need to install high-precision detection components in the cell. Therefore, it is possible to achieve reasonable control of the charging and discharging process of the battery cell at a lower cost.

[0009] According to a second aspect of the embodiments of this application, an electrochemical device control method is provided for controlling the charge and discharge of a single battery cell. The electrochemical device control method includes: acquiring battery cell temperature parameters, the battery cell temperature parameters including at least one of the initial discharge temperature, maximum discharge temperature, initial charging temperature, and maximum charging temperature of the battery cell; determining a battery cell health level corresponding to the battery cell temperature parameters according to a predetermined first correspondence, the battery cell health level indicating the health status of the battery cell; if the battery cell health level is less than a preset first health level threshold and greater than a preset second health level threshold, configuring the battery cell to perform at least one of reducing the upper limit charging voltage, reducing the charging current, reducing the discharge current, or increasing the lower limit discharging voltage, wherein the second health level threshold is less than the first health level threshold; if the battery cell health level is less than the second health level threshold, issuing a warning message indicating a restriction on the use of the battery cell. Since there is a correspondence between the battery cell temperature parameters and the battery cell health level, the battery cell health level can be determined based on the battery cell temperature parameters, and then the charge and discharge of the battery cell can be controlled based on the battery cell health level, improving the cycle performance of the battery cell, reducing safety risks, and achieving reasonable control of the battery cell charge and discharge process. The health of the battery cell is determined based on its temperature parameters, and then the charging and discharging process of the battery cell is controlled according to the health of the battery cell. Only the temperature of the battery cell needs to be detected, without the need to set up high-precision detection components in the battery cell, so that the reasonable control of the charging and discharging process of the battery cell can be achieved at a lower cost.

[0010] According to a third aspect of the embodiments of this application, an electrochemical device control method is provided for charging and discharging control of a battery pack including multiple cells. The electrochemical device control method includes: acquiring battery pack temperature parameters, the battery pack temperature parameters including at least one of the initial discharge temperature, maximum discharge temperature, initial charging temperature, and maximum charging temperature of at least two cells in the battery pack; if the battery pack temperature parameters meet a third condition, configuring at least one cell in the battery pack to perform at least one of reducing the upper limit charging voltage, reducing the charging current, reducing the discharge current, or increasing the lower limit discharging voltage; if the battery pack temperature parameters meet a fourth condition, issuing a warning message to indicate that the battery pack should be stopped. As the capacity retention rate of battery cells decreases, the cell impedance increases. Increased cell impedance leads to increased heat generation during charging and discharging, thus affecting the cell temperature. Since a battery pack consists of multiple cells, the battery pack temperature parameters will change accordingly as the capacity retention rate decreases. There is a correlation between battery pack temperature parameters and capacity retention rate, which characterizes the health of the cells. Therefore, the charging and discharging process of the battery pack can be controlled based on its temperature parameters to improve cycle performance, reduce safety risks, and achieve reasonable control. Controlling the charging and discharging process based on battery pack temperature parameters only requires detecting the temperature of the cells within the battery pack, eliminating the need for high-precision detection components. This allows for reasonable control of the charging and discharging process at a lower cost.

[0011] In one possible implementation, the third condition includes: the maximum discharge temperature of the first cell in the battery pack is greater than a preset ninth threshold and less than a preset tenth threshold, and / or the maximum temperature difference of the battery pack is greater than a preset eleventh threshold and less than a preset twelfth threshold, wherein the first cell is the cell in the battery pack with the highest maximum discharge temperature determined based on the battery pack temperature parameters, the second cell is the cell in the battery pack with the lowest maximum discharge temperature determined based on the battery pack temperature parameters, the maximum temperature difference is equal to the difference between the maximum discharge temperatures of the first cell and the second cell, the ninth threshold is less than the tenth threshold, and the eleventh threshold is less than the twelfth threshold; the fourth condition includes: the maximum discharge temperature of the first cell is greater than the tenth threshold, and / or the maximum temperature difference is greater than the twelfth threshold. Since the capacity retention rate of the battery pack is correlated with the maximum discharge temperature and the maximum temperature difference, and the capacity retention rate of the battery pack can characterize the health status of the battery pack, the charging and discharging of the battery pack can be controlled according to the maximum discharge temperature and the maximum temperature difference of the battery pack, thereby improving the cycle performance of the battery pack, reducing the safety risks of the battery pack, and achieving reasonable control of the charging and discharging process of the battery pack. By controlling the charging and discharging process of the battery pack based on its maximum discharge temperature and maximum temperature difference, it is only necessary to detect the temperature of the cells during the discharge process. There is no need to install high-precision detection components in the battery pack, thus enabling reasonable control of the charging and discharging process of the battery pack at a lower cost.

[0012] In one possible implementation, configuring at least one cell in the battery pack to perform at least one of reducing the upper limit charging voltage, reducing the charging current, reducing the discharging current, or increasing the lower limit discharging voltage includes: configuring the first cell to reduce the upper limit charging voltage, reduce the charging current, reduce the discharging current, or increase the lower limit discharging voltage. Since the first cell has the highest maximum discharge temperature in the battery pack, its capacity retention rate decays faster than other cells, and its expansion rate increases more rapidly. By reducing the upper limit charging voltage and charging current of the first cell, and increasing its lower limit discharging voltage, the impact on the battery pack's range can be reduced while extending the battery pack's lifespan, thereby ensuring a better user experience.

[0013] According to a fourth aspect of the present application, an electrochemical device control method is provided for charging and discharging control of a battery pack including multiple cells. The electrochemical device control method includes: acquiring battery pack temperature parameters, the battery pack temperature parameters including at least one of the initial discharge temperature, maximum discharge temperature, initial charging temperature, and maximum charging temperature of at least two cells in the battery pack; determining a battery pack health level corresponding to the battery pack temperature parameters according to a predetermined second correspondence, the battery pack health level indicating the health status of the battery pack; if the battery pack health level is less than a preset third health level threshold and greater than a preset fourth health level threshold, configuring at least one cell in the battery pack to perform at least one of reducing the upper limit charging voltage, reducing the charging current, reducing the discharge current, or increasing the lower limit discharging voltage, wherein the fourth health level threshold is less than the third health level threshold; if the battery pack health level is less than the fourth health level threshold, issuing a warning message indicating to stop using the battery pack. Since there is a correlation between battery pack temperature parameters and battery pack health, the battery pack health can be determined based on these parameters. This allows for control of the battery pack's charging and discharging processes based on its health status, improving cycle performance, reducing safety risks, and achieving rational control of the charging and discharging process. Determining battery pack health based on temperature parameters and then controlling the charging and discharging process accordingly only requires monitoring the temperature of the individual battery cells, eliminating the need for high-precision detection components within the battery pack. This allows for rational control of the charging and discharging process at a lower cost.

[0014] According to a fifth aspect of the embodiments of this application, an electronic device is provided, including: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other through the communication bus; the memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the electrochemical device control method described in any of the above aspects.

[0015] According to a sixth aspect of the embodiments of this application, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the electrochemical device control method as described in any of the preceding aspects.

[0016] According to a seventh aspect of the present application, a computer program product is provided, which is stored on a computer-readable medium and includes computer-executable instructions that, when executed, cause at least one processor to perform the electrochemical device control method of any of the foregoing embodiments.

[0017] As can be seen from the above technical solution, since there is a correlation between the cell temperature parameter and the cell capacity retention rate, and the cell capacity retention rate can characterize the cell's health status, the charging and discharging of the cell can be controlled based on the cell temperature parameter. This improves the cell's cycle performance, reduces safety risks, and achieves reasonable control of the cell's charging and discharging process. Controlling the cell's charging and discharging process based on the cell temperature parameter only requires detecting the cell temperature, eliminating the need for high-precision detection components within the cell. Therefore, reasonable control of the cell's charging and discharging process can be achieved at a lower cost. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a flowchart of an electrochemical device control method according to an embodiment of this application;

[0020] Figure 2 This is a graph showing the changes in cell impedance and capacity retention rate with the number of cycles according to an embodiment of this application;

[0021] Figure 3 This is a graph showing the change in the maximum discharge temperature of a battery cell according to one embodiment of this application as a function of the number of cycles.

[0022] Figure 4 This is a temperature change curve of the battery cell during the charging and discharging process according to an embodiment of this application;

[0023] Figure 5 This is a schematic diagram illustrating the change in cell cycle performance according to one embodiment of this application;

[0024] Figure 6 This is a flowchart of an electrochemical device control method according to another embodiment of this application;

[0025] Figure 7 This is a flowchart of an electrochemical device control method according to another embodiment of this application;

[0026] Figure 8 This is a graph showing the change in battery pack capacity retention and maximum discharge temperature with the number of cycles according to one embodiment of this application.

[0027] Figure 9 This is a curve showing the change in capacity retention and maximum temperature difference of a battery pack according to one embodiment of this application as a function of the number of cycles;

[0028] Figure 10This is a flowchart of an electrochemical device control method according to another embodiment of this application;

[0029] Figure 11 This is a schematic diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0031] The specific implementation of the embodiments of this application is described below with reference to the accompanying drawings. It should be noted that, in the embodiments of this application, the electrochemical device may be a lithium-ion battery, but the electrochemical device of this application is not limited to lithium-ion batteries.

[0032] Electrochemical device control methods

[0033] This application will use a single battery cell and a battery pack containing multiple battery cells as the objects of charge and discharge control, and will describe the charge and discharge control methods for a single battery cell and a battery pack respectively. Specifically, the charge and discharge control method for a single battery cell will be described through Embodiment 1 and Embodiment 2, and the charge and discharge control method for a battery pack will be described through Embodiment 3 and Embodiment 4.

[0034] Example 1

[0035] Figure 1 This is a flowchart of an electrochemical device control method provided in Embodiment 1 of this application, which is used for charge and discharge control of a single battery cell. Figure 1 As shown, the control method for this electrochemical device includes the following steps:

[0036] Step 101: Obtain cell temperature parameters.

[0037] Cell temperature parameters are used to indicate the temperature information of the controlled cell, and may specifically include any one or more of the cell's initial discharge temperature, maximum discharge temperature, initial charging temperature, and maximum charging temperature.

[0038] Initial discharge temperature refers to the temperature of the battery cell when it begins to discharge in each charge-discharge cycle. Maximum discharge temperature refers to the highest temperature the battery cell can reach during discharge. Initial charge temperature refers to the temperature of the battery cell when it begins to charge in each charge-discharge cycle. Maximum charge temperature refers to the highest temperature the battery cell can reach during charging.

[0039] The initial discharge temperature, maximum discharge temperature, initial charging temperature, and maximum charging temperature of the battery cell can be the surface temperature of the cell, detected by a temperature sensor installed on the cell surface. The temperature sensor can be located at the intersection of the diagonals of the cell surface, and the temperature sensor can be a temperature sensing wire.

[0040] Step 102: Determine whether the cell temperature parameters meet the first and second conditions.

[0041] The first and second conditions are used to determine the health status of the battery cell based on its temperature parameters. The inputs to the first and second conditions can be the battery cell temperature detected by a temperature sensor, or other relevant data obtained based on the battery cell temperature.

[0042] Step 103: If the cell temperature parameters meet the first condition, then configure the cell to perform at least one of the following: reduce the upper limit of charging voltage, reduce the charging current, reduce the discharging current, or increase the lower limit of discharging voltage.

[0043] If the cell temperature parameters meet the first condition, it means that the cell's capacity retention rate has decreased to a certain extent. At this time, reducing the upper limit voltage or reducing the charging current during the charging process and increasing the lower limit voltage during the discharging process can improve the cell's cycle performance and extend its service life.

[0044] Step 104: If the cell temperature parameter meets the second condition, a warning message is issued to indicate that the cell should be stopped.

[0045] If the cell temperature parameters meet the second condition, it indicates that the cell's capacity retention rate has significantly decreased, and the cell's range and power performance have obviously declined, affecting the user experience. For lithium-ion batteries, there may also be interface problems such as lithium plating and purple spots due to insufficient electrolyte, which can easily lead to thermal runaway and safety risks. Therefore, a warning message is issued to remind users to stop using the cell.

[0046] Figure 2 One embodiment of this application provides a graph showing the variation of cell impedance and capacity retention rate with the number of cycles. Figure 3 This is a graph showing the change in the maximum discharge temperature of a battery cell as a function of the number of cycles, according to one embodiment of this application. Figure 2 In the diagram, curve 201 shows the change in cell capacity retention with the number of cycles, and curve 202 shows the change in cell impedance with the number of cycles. Figure 2 It is known that the decay of cell capacity retention is accompanied by an increase in cell impedance. Increased cell impedance leads to increased heat generation during charging and discharging, which in turn increases the maximum discharge and maximum charging temperatures of the cell. For example... Figure 3 As shown, with the increase of the number of battery cell cycles, the capacity retention rate of the battery cell decreases, the battery cell impedance increases, and the maximum discharge temperature of the battery cell gradually increases.

[0047] Depend on Figure 2 and Figure 3 It is known that as the cell capacity retention rate decreases, the cell impedance increases. The increased cell impedance will increase the heat generated during the cell charging and discharging process, which in turn affects the cell temperature during the charging and discharging process. Therefore, there is a correlation between the cell capacity retention rate and the cell temperature. Thus, the charging and discharging of the cell can be controlled based on the cell temperature parameter, so that the charging and discharging process of the cell can be reasonably controlled according to the health status of the cell.

[0048] In this embodiment, since there is a correlation between cell temperature parameters and cell capacity retention, and cell capacity retention can characterize the cell's health status, the charging and discharging of the cell can be controlled based on the cell temperature parameters. This improves the cell's cycle performance, reduces safety risks, and achieves reasonable control of the cell's charging and discharging process. Controlling the cell's charging and discharging process based on cell temperature parameters only requires detecting the cell's temperature, eliminating the need for high-precision detection components within the cell. This allows for reasonable control of the cell's charging and discharging process at a lower cost.

[0049] In one possible implementation, the first and second conditions can be defined based on the maximum charging temperature or the maximum discharging temperature. The first and second conditions based on the maximum charging temperature or the maximum discharging temperature are explained below.

[0050] When defining the first and second conditions based on the maximum charging temperature, the first condition is that the maximum charging temperature of the battery cell is greater than a first temperature threshold and less than a second temperature threshold, and the second condition is that the maximum charging temperature of the battery cell is greater than or equal to the second temperature threshold. When defining the first and second conditions based on the maximum discharging temperature, the first condition is that the maximum discharging temperature of the battery cell is greater than the first temperature threshold and less than the second temperature threshold, and the second condition is that the maximum discharging temperature of the battery cell is greater than or equal to the second temperature threshold. Wherein, the first temperature threshold is less than the second temperature threshold.

[0051] As the cell's capacity retention rate decreases and its impedance increases, the heat generated during charging and discharging increases, leading to higher maximum charging and discharging temperatures. When the maximum charging or discharging temperature exceeds a first temperature threshold but falls below a second temperature threshold, significant irreversible capacity decay occurs. In this case, reducing the upper charging voltage and current, and increasing the lower discharging voltage, can improve the cell's cycle performance. When the maximum charging or discharging temperature exceeds the second temperature threshold, even greater irreversible capacity decay occurs, resulting in decreased battery life and power performance. This leads to a poor user experience and increases the risk of thermal runaway, posing a safety hazard. Therefore, warning messages are displayed to prompt users to stop using the cell.

[0052] In one example, the first temperature threshold ranges from 50 to 60°C, and the second temperature threshold ranges from 60 to 80°C. For instance, the first temperature threshold could be 50°C, 55°C, or 60°C, and the second temperature threshold could be 62°C, 65°C, 70°C, 75°C, or 80°C. The first and second temperature thresholds within their respective ranges can be arbitrarily combined.

[0053] In one possible implementation, the first and second conditions can be defined based on the discharge temperature growth rate and / or charging temperature growth rate of the battery cell. The first and second conditions based on the discharge temperature growth rate and / or charging temperature growth rate are explained below, where the discharge temperature growth rate = (maximum discharge temperature - initial discharge temperature) / discharge time, and the charging temperature growth rate = (maximum charging temperature - initial charging temperature) / charging time.

[0054] When defining the first and second conditions based on the discharge temperature growth rate, the first condition is that the discharge temperature growth rate of the battery cell is greater than a first threshold and less than a second threshold, and the second condition is that the discharge temperature growth rate of the battery cell is greater than or equal to the second threshold. When defining the first and second conditions based on the charging temperature growth rate, the first condition is that the charging temperature growth rate of the battery cell is greater than a third threshold and less than a fourth threshold, and the second condition is that the charging temperature growth rate of the battery cell is greater than or equal to the fourth threshold. Wherein, the first threshold is less than the second threshold, and the third threshold is less than the fourth threshold.

[0055] Figure 4 This is a temperature change curve of the battery cell during charging and discharging, provided in one embodiment of this application. Figure 4As shown, curve 41 represents the temperature change curve of the battery cell during the first cycle, and curve 42 represents the temperature curve of the battery cell during the 300th cycle. The portion of curve 41 within the dashed box 411 represents the temperature change curve of the battery cell during the charging process of the first cycle, and the portion within the dashed box 412 represents the temperature change curve of the battery cell during the discharging process of the first cycle. The portion of curve 42 within the dashed box 421 represents the temperature change curve of the battery cell during the charging process of the 300th cycle, and the portion within the dashed box 422 represents the temperature change curve of the battery cell during the discharging process of the 300th cycle.

[0056] like Figure 4 As shown, the slope of curve 41 within dashed box 411 is less than the slope of curve 42 within dashed box 421, and the slope of curve 41 within dashed box 412 is less than the slope of curve 42 within dashed box 422. This means that in the 300th cycle compared to the 1st cycle, both the charging temperature growth rate and the discharging temperature growth rate of the battery cell increase. This is because as the number of cycles increases, the capacity retention rate of the battery cell decreases, and this decrease is accompanied by an increase in cell impedance. Increased cell impedance leads to increased heat generation and heating rate during charging and discharging, which in turn increases the charging temperature growth rate and the discharging temperature growth rate. Therefore, there is a correlation between the charging temperature growth rate and the discharging temperature growth rate of the battery cell and the capacity retention rate. Since the capacity retention rate characterizes the health of the battery cell, charging and discharging control can be performed based on the charging temperature growth rate and the discharging temperature growth rate of the battery cell, achieving reasonable control of the charging and discharging process according to the health status of the battery cell.

[0057] As the cell's capacity retention rate decreases, its impedance increases, leading to increased heat generation and rate of heating during charging and discharging. This results in a faster rate of increase in both charging and discharging temperatures. When the cell's discharge temperature growth rate exceeds a first threshold but is less than a second threshold, and / or the cell's charging temperature growth rate exceeds a third threshold but is less than a fourth threshold, significant irreversible capacity decay occurs. In this case, reducing the upper charging voltage and charging current, and increasing the lower discharging voltage, can improve the cell's cycle life. When the cell's discharge temperature growth rate is greater than or equal to the second threshold, and / or the cell's charging temperature growth rate is greater than or equal to the fourth threshold, even greater irreversible capacity decay occurs. This reduces the cell's range and power performance, leading to a poor user experience and increasing the risk of thermal runaway and safety hazards. Therefore, warning messages are used to prompt users to stop using the cell.

[0058] In one example, the first threshold ranges from 2 to 5 °C / min, and the second threshold ranges from 5 to 10 °C / min. For instance, the first threshold can be 2 °C / min, 2.5 °C / min, 3 °C / min, 4 °C / min, or 5 °C / min, and the second threshold can be 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min, or 10 °C / min. The values ​​of the first and second thresholds within their respective ranges can be arbitrarily combined.

[0059] In one example, the third threshold ranges from 2 to 5 °C / min, and the fourth threshold ranges from 5 to 10 °C / min. For instance, the third threshold can be 2 °C / min, 2.5 °C / min, 3 °C / min, 4 °C / min, or 5 °C / min, and the fourth threshold can be 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min, or 10 °C / min. The values ​​of the third and fourth thresholds within their respective ranges can be arbitrarily combined.

[0060] In this embodiment, since the charging temperature growth rate and discharging temperature growth rate of the battery cell are correlated with the capacity retention rate, and the capacity retention rate can characterize the health status of the battery cell, controlling the charging and discharging of the battery cell based on the charging temperature growth rate and discharging temperature growth rate allows for the adoption of corresponding charging and discharging strategies in response to different health states of the battery cell. This improves the cycle performance of the battery cell, reduces safety risks, and achieves reasonable control of the charging and discharging process. Determining the charging temperature growth rate and discharging temperature growth rate only requires detecting the temperature during the charging and discharging process, eliminating the need for high-precision detection components within the battery cell. Therefore, reasonable control of the charging and discharging process can be achieved at a lower cost.

[0061] In one possible implementation, the first and second conditions can be defined based on the cell's maximum discharge temperature growth rate and / or maximum charge temperature growth rate. The first and second conditions defined based on the maximum discharge temperature growth rate and / or maximum charge temperature growth rate are explained below.

[0062] The maximum discharge temperature growth rate indicates the rate at which the maximum discharge temperature of a battery cell increases with the number of battery cell cycles. The maximum discharge temperature growth rate of a battery cell can be defined by the following formula (1):

[0063] K n =(T n -T n-1 ) / (T n-1 -T n-2 )#(1)

[0064] K nT is used to characterize the slope of the maximum discharge temperature increase. n T is used to characterize the maximum discharge temperature of the battery cell during the nth charge-discharge cycle. n-1 T is used to characterize the maximum discharge temperature of the battery cell during the (n-1)th charge-discharge cycle. n-1 The maximum discharge temperature of the cell is used to characterize the (n-2)th charge-discharge cycle, where the nth charge-discharge cycle is the current charge-discharge cycle of the cell, and n≥3.

[0065] The maximum charging temperature growth rate indicates the rate at which the maximum charging temperature of a battery cell increases with the number of battery cell cycles. The maximum charging temperature growth rate of a battery cell can be defined by the following formula (2):

[0066] K m =(T m -T m-1 ) / (T m-1 -T m-2 )#(2)

[0067] K m T is used to characterize the slope of the maximum charging temperature increase. m T is used to characterize the maximum charging temperature of the battery cell during the m-th charge-discharge cycle. m-1 T is used to characterize the maximum charging temperature of the battery cell during the (m-1)th charge-discharge cycle. m-1 The maximum charging temperature of the cell during the (m-2)th charge-discharge cycle is used to characterize the cell's current charge-discharge cycle, where m ≥ 3.

[0068] When defining the first and second conditions based on the maximum discharge temperature growth rate, the first condition is that the maximum discharge temperature growth rate is greater than the fifth threshold and less than the sixth threshold, and the second condition is that the maximum discharge temperature growth rate is greater than or equal to the sixth threshold. When defining the first and second conditions based on the maximum charging temperature growth rate, the first condition is that the maximum charging temperature growth rate is greater than the seventh threshold and less than the eighth threshold, and the second condition is that the maximum charging temperature growth rate is greater than or equal to the eighth threshold. Wherein, the fifth threshold is less than the sixth threshold, and the seventh threshold is less than the eighth threshold.

[0069] As the cell capacity retention rate decreases, the cell impedance increases, leading to increased heat generation during charging and discharging, and consequently, increased maximum discharge and maximum charging temperatures. Furthermore, the rate of increase in maximum discharge and maximum charging temperatures increases with the number of cell cycles. When the rate of increase in maximum discharge temperature exceeds the fifth threshold but is less than the sixth threshold, and / or when the rate of increase in maximum charging temperature exceeds the seventh threshold but is less than the eighth threshold, significant irreversible capacity decay occurs. In this case, reducing the upper limit charging voltage and charging current, and increasing the lower limit discharge voltage, can improve the cell's cycle performance. When the rate of increase in maximum discharge temperature is greater than or equal to the sixth threshold, and / or when the rate of increase in maximum charging temperature is greater than the eighth threshold, even greater irreversible capacity decay occurs, resulting in decreased battery life and power performance. This leads to a poor user experience and increases the risk of thermal runaway, posing a safety hazard. Therefore, warning messages are used to prompt users to stop using the cell.

[0070] In one example, the fifth threshold ranges from 1.2 to 2, and the sixth threshold ranges from 2 to 5. For instance, the fifth threshold can be 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2, and the sixth threshold can be 2, 3, 4, or 5. The values ​​of the fifth and sixth thresholds within their respective ranges can be combined arbitrarily.

[0071] In one example, the seventh threshold ranges from 1.2 to 2, and the eighth threshold ranges from 2 to 5. For instance, the seventh threshold can be 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2, and the eighth threshold can be 2, 3, 4, or 5. The values ​​of the seventh and eighth thresholds within their respective ranges can be combined arbitrarily.

[0072] In this embodiment, since the cell capacity retention rate, maximum discharge temperature growth rate, and maximum charge temperature growth rate are all related to the cell's internal resistance, there is a correlation between the cell's maximum discharge temperature growth rate and maximum charge temperature growth rate and the cell capacity retention rate. Since the cell capacity retention rate characterizes the cell's health status, controlling the cell's charge and discharge based on its maximum discharge temperature growth rate and maximum charge temperature growth rate allows for the adoption of corresponding charge and discharge strategies in response to different cell health states. This improves the cell's cycle performance, reduces safety risks, and achieves reasonable control of the cell's charge and discharge process. Determining the cell's maximum discharge temperature growth rate and maximum charge temperature growth rate only requires detecting the temperature during the cell's charge and discharge process, eliminating the need for high-precision detection components within the cell. Therefore, reasonable control of the cell's charge and discharge process can be achieved at a lower cost.

[0073] It should be noted that when the cell temperature parameters meet the first condition, configuring the cell to reduce the upper limit of charging voltage, reduce the charging current, reduce the discharging current, or increase the lower limit of discharging voltage can improve the cell's cycle performance, slow down the decay rate of cell capacity retention and the increase rate of cell expansion, thereby extending the cell's service life and improving cell safety.

[0074] Figure 5 This is a schematic diagram illustrating the change in cell cycle performance according to one embodiment of this application. Figure 5 As shown, curve 501 shows the change in capacity retention rate of the cell during normal cycling as the number of cycles increases; curve 502 shows the change in capacity retention rate of the cell during buck cycling as the number of cycles increases; curve 503 shows the change in cell expansion rate of the cell during normal cycling as the number of cycles increases; and curve 504 shows the change in cell expansion rate of the cell during buck cycling as the number of cycles increases.

[0075] In this embodiment, a regular battery cell cycle refers to constant current and constant voltage charging of the battery cell from the first cycle to the last cycle, with a charging upper limit voltage of 4.20V. A buck battery cell cycle refers to constant current and constant voltage charging of the battery cell from the 1st to the 198th cycle, with a charging upper limit voltage of 4.20V; constant current and constant voltage charging of the battery cell from the 199th to the 298th cycle, with a charging upper limit voltage of 4.15V; and constant current and voltage charging of the battery cell from the 299th to the last cycle, with a charging upper limit voltage of 4.10V. The capacity retention rate for the first to 198th cycles of the buck battery cell cycle is 95%-100%, and the capacity retention rate for the 199th to 298th cycles of the buck battery cell cycle is 92%-95%.

[0076] like Figure 5 As shown in curves 501 and 502, in the early stage of cell cycling (from the 1st to the 440th cycle), the capacity retention rate of the conventional cycle is greater than that of the buck cycle. In the later stage of cell cycling (from the 440th to the last cycle), the capacity retention rate of the conventional cycle is less than that of the buck cycle. Therefore, the advantage of the buck cycle will be reflected in the later stage of cell cycling, slowing down the decay rate of the capacity retention rate in the later stage of cell cycling and extending the service life of the cell.

[0077] like Figure 5As shown in curves 503 and 504, in the early stage of cell cycling (from the 1st to the 400th cycle), the cell expansion rate of the conventional cycle is basically the same as that of the buck cycle. However, in the later stage of cell cycling (from the 400th to the last cycle), the cell expansion rate of the conventional cycle is greater than that of the buck cycle, and the rate of increase of the cell expansion rate of the conventional cycle is greater than that of the buck cycle. Therefore, the advantage of the buck cycle will be reflected in the later stage of cell cycling, slowing down the rate of increase of the cell expansion rate in the later stage of cell cycling, so as to extend the cell life.

[0078] Example 2

[0079] Figure 6 This is a flowchart of an electrochemical device control method provided in Embodiment 2 of this application, which is used for charge and discharge control of a single battery cell. Figure 6 As shown, the control method for this electrochemical device includes the following steps:

[0080] Step 601: Obtain cell temperature parameters.

[0081] For details on obtaining the cell temperature parameters, please refer to the description in step 101 of the aforementioned embodiment, which will not be repeated here.

[0082] Step 602: Determine the cell health corresponding to the cell temperature parameters based on the predetermined first correspondence.

[0083] As the cell capacity retention rate decreases, the cell impedance increases. Increased cell impedance leads to increased heat generation during cell charging and discharging, which in turn affects the cell temperature during charging and discharging. Therefore, there is a correlation between the cell capacity retention rate and the cell temperature. The cell capacity retention rate can characterize the cell's health status. Thus, there is a specific correspondence between the cell temperature parameter and the cell health. Based on this correspondence, the cell health corresponding to the cell temperature parameter can be determined.

[0084] Cell health can indicate the health status of a cell; for example, cell health can be expressed as the cell's capacity retention rate.

[0085] The first correspondence can be a table that includes the correspondence between cell temperature parameters and cell health, or it can be a data processing model that determines cell health based on cell temperature parameters. This application does not limit this.

[0086] Step 603: Determine the relationship between the cell health status and the first and second health status thresholds.

[0087] The first health threshold and the second health threshold are preset health thresholds, with the first health threshold being greater than the second health threshold. When the cell's health is less than the first health threshold but greater than the second health threshold, the cell's overall health decreases, its capacity retention rate declines, and the cell expands. When the cell's health is less than the second health threshold, the cell's health declines significantly, resulting in a noticeable degradation in its range and power performance, leading to a poor customer experience.

[0088] In one example, cell health refers to the cell's capacity retention rate. The first health threshold ranges from 80% to 95%, preferably 90% to 95%, and can be 90%, 92%, or 95%, etc. The second health threshold ranges from 30% to 80%, preferably 60% to 80%, and can be 60% or 80%. For example, the first health threshold is 80%, and the second health threshold is 60%, because when the cell's capacity retention rate drops below 80%, the cell's range and power performance significantly decrease, resulting in a poor user experience. When the cell's capacity retention rate drops below 60%, the cell may experience interface problems such as lithium plating and purple spots due to insufficient electrolyte, which can easily lead to thermal runaway and safety risks.

[0089] Step 604: If the cell health is less than the first health threshold and greater than the second health threshold, then configure the cell to perform at least one of the following actions: reduce the upper limit of charging voltage, reduce the charging current, reduce the discharging current, or increase the lower limit of discharging voltage.

[0090] If the cell health status is less than the first health status threshold but greater than the second health status threshold, it indicates that the cell's health status has deteriorated to a certain extent. In this case, reducing the upper limit voltage and / or charging current during the charging process and increasing the lower limit voltage during the discharging process can improve the cell's cycle performance and extend its service life.

[0091] Step 605: If the cell health is less than the second health threshold, issue a warning message to indicate that the cell should be stopped.

[0092] If the cell health status is less than or equal to the second health status threshold, it indicates that the cell's health status has seriously deteriorated, the cell's capacity retention rate has decreased significantly, the cell has shown significant expansion, and the cell's range and power performance have decreased significantly, affecting the user experience. For lithium-ion batteries, there may also be interface problems such as lithium plating and purple spots due to insufficient electrolyte, which can easily lead to thermal runaway and safety risks. Therefore, a warning message is issued to remind users to stop using the cell.

[0093] In this embodiment, since there is a correlation between cell temperature parameters and cell health, the cell health can be determined based on the cell temperature parameters. Therefore, the charging and discharging of the cell can be controlled based on the cell health, improving the cell's cycle performance, reducing safety risks, and achieving reasonable control of the cell's charging and discharging process. Determining the cell health based on cell temperature parameters and then controlling the charging and discharging process based on that health only requires detecting the cell temperature, eliminating the need for high-precision detection components within the cell. This allows for reasonable control of the cell's charging and discharging process at a lower cost.

[0094] In one possible implementation, multiple first health thresholds can be preset, each of which is greater than a second health threshold. When the cell's health degrades to a certain first health threshold, a corresponding strategy is used to control the cell's charging and discharging process. For example, as the cell's health degrades, the charging voltage of the cell is gradually reduced in multiple stages. For instance, when the cell is charged and discharged according to the buck cycle in the aforementioned embodiment, when the cell's capacity retention rate degrades to 95%, the charging voltage is reduced by 20mV; when the cell's capacity retention rate degrades to 92%, the charging voltage is further reduced by 30mV; and when the cell's capacity retention rate degrades to 90%, the charging voltage is further reduced by 50mV.

[0095] In this embodiment, multiple first health thresholds are preset, and different first health thresholds correspond to different charging and discharging strategies. The charging and discharging strategies can be to reduce the charging voltage and charging current of the battery cell, or to increase the lower limit voltage of the battery cell's discharge. Thus, when the battery cell's health decays to different first health thresholds, a strategy corresponding to the corresponding first health threshold is adopted to control the charging and discharging process of the battery cell. This can improve the cycling and expansion problems in the later stages of battery cell cycling, reduce the impact on the capacity retention rate in the early stages of battery cell cycling, and thereby improve the user experience.

[0096] Example 3

[0097] Figure 7 This is a flowchart of an electrochemical device control method provided in Embodiment 3 of this application. This method is used for charging and discharging control of a battery pack comprising multiple cells. Figure 7 As shown, the control method for this electrochemical device includes the following steps:

[0098] Step 701: Obtain battery pack temperature parameters.

[0099] Battery pack temperature parameters are used to indicate the temperature information of the controlled battery pack, and may specifically include at least one of the initial discharge temperature, maximum discharge temperature, initial charging temperature and maximum charging temperature of at least two cells in the battery pack.

[0100] The battery pack includes at least two cells connected in series and / or in parallel.

[0101] Temperature sensors are installed on the surface of the battery cells in the battery pack. These sensors detect the temperature of the cells during charging and discharging, thus obtaining the battery pack's temperature parameters. Temperature sensors can be placed on the surface of each cell in the battery pack to detect the temperature of all cells and use this as the overall battery pack temperature parameter. Alternatively, temperature sensors can be placed on the surfaces of only some cells in the battery pack, such as the innermost and outermost cells, to control the cost of the battery pack.

[0102] Step 702: Determine whether the battery pack temperature parameters meet the third and fourth conditions.

[0103] The third and fourth conditions are used to determine the health status of the battery pack based on its temperature parameters. The inputs to the third and fourth conditions can be the cell temperature detected by the temperature sensor, or other relevant data obtained based on the cell temperature.

[0104] Step 703: If the battery pack temperature parameters meet the third condition, then configure at least one cell in the battery pack to perform at least one of the following: reduce the upper limit of charging voltage, reduce the charging current, reduce the discharging current, or increase the lower limit of discharging voltage.

[0105] If the battery pack temperature parameters meet the first condition, it indicates that the battery pack's capacity retention rate has already decreased to a certain extent. At this time, reducing the upper limit voltage of some or all cells during the charging and discharging process, or reducing the charging current, and increasing the lower limit voltage of some or all cells during the discharging process, can improve the cycle performance of the battery pack and extend its service life.

[0106] Step 704: If the battery pack temperature parameters meet the fourth condition, issue a warning message to indicate that the battery pack should be stopped.

[0107] If the battery pack temperature parameters meet the fourth condition, it indicates that the battery pack's capacity retention rate has significantly decreased, and the battery pack's range and power performance have obviously declined, affecting the user experience. For lithium-ion battery packs, there may also be interface problems such as lithium plating and purple spots due to insufficient electrolyte, which can easily lead to thermal runaway and safety risks. Therefore, a warning message is issued to remind the user to stop using the battery pack.

[0108] In this embodiment, as the cell capacity retention rate decreases, the cell impedance increases. This increased impedance leads to increased heat generation during charging and discharging, affecting the cell temperature. Since a battery pack comprises multiple cells, the battery pack temperature parameters will change accordingly as the battery pack capacity retention rate decreases. There is a correlation between battery pack temperature parameters and battery pack capacity retention rate, which characterizes the health of the cells. Therefore, the charging and discharging of the battery pack can be controlled based on the battery pack temperature parameters to improve cycle performance, reduce safety risks, and achieve reasonable control of the charging and discharging process. Controlling the charging and discharging process based on battery pack temperature parameters only requires detecting the temperature of the cells within the battery pack, eliminating the need for high-precision detection components. This allows for reasonable control of the charging and discharging process at a lower cost.

[0109] In one possible implementation, the third and fourth conditions can be defined based on the maximum discharge temperature of the cells in the battery pack and / or the maximum temperature difference of the battery pack. The second and third conditions based on the maximum discharge temperature and / or maximum temperature difference are explained below.

[0110] When defining the third and fourth conditions based on the maximum discharge temperature, the third condition is that the maximum discharge temperature of the first battery cell is greater than the ninth threshold and less than the tenth threshold, and the fourth condition is that the maximum discharge temperature of the first battery cell is greater than the tenth threshold. When defining the third and fourth conditions based on the maximum temperature difference, the third condition is that the maximum temperature difference of the battery pack is greater than the eleventh threshold and less than the twelfth threshold, and the fourth condition is that the maximum temperature difference of the battery pack is greater than the twelfth threshold. Here, the first battery cell is the cell in the battery pack with the highest maximum discharge temperature determined based on the battery pack temperature parameters, the second battery cell is the cell in the battery pack with the lowest maximum discharge temperature determined based on the battery pack temperature parameters, the maximum temperature difference is equal to the difference between the maximum discharge temperatures of the first and second battery cells, the ninth threshold is less than the tenth threshold, and the eleventh threshold is less than the twelfth threshold.

[0111] Because the battery cells in a battery pack are of standard models, the temperature of the inner cells is higher than that of the outer cells. Therefore, the first cell is usually the inner cell of the battery pack, and the second cell is usually the outer cell. For example, in a battery pack containing five cells connected in series, with cells 1 to 5 arranged sequentially, cell 3 is the inner cell (first cell) of the battery pack, and cell 1 or cell 5 is the outer cell (second cell).

[0112] Figure 8 This is a graph showing the change in battery pack capacity retention and maximum discharge temperature with the number of cycles, according to one embodiment of this application. Figure 8In the diagram, curve 801 shows the battery pack's capacity retention rate as a function of cycle number, and curve 802 shows the battery pack's maximum discharge temperature as a function of cycle number. For example... Figure 8 As shown, with the increase of the number of battery cycles, the capacity retention rate of the battery pack gradually decreases, while the maximum discharge temperature of the battery pack gradually increases. This is because the decrease in the capacity retention rate is accompanied by an increase in cell impedance. The increased cell impedance in the battery pack will increase the heat generated during the discharge process, which will lead to a corresponding increase in the maximum discharge temperature of the battery pack. Therefore, there is a correlation between the capacity retention rate and the maximum discharge temperature of the battery pack. The capacity retention rate can characterize the health status of the battery pack, and the charging and discharging process of the battery pack can be controlled based on the maximum discharge temperature of the battery pack to extend the service life of the battery pack and ensure the safety of battery pack use.

[0113] Figure 9 This is a curve showing the change in capacity retention and maximum temperature difference of a battery pack as a function of cycle number, according to one embodiment of this application. Figure 9 As shown, curve 901 represents the change in battery pack capacity retention rate with the number of cycles, and curve 902 represents the change in the maximum temperature difference of the battery pack with the number of cycles. Figure 9 As shown, with the increase of the number of battery cycles, the capacity retention rate of the battery pack gradually decreases, while the maximum temperature difference of the battery pack gradually increases. This is because the decrease in the capacity retention rate is accompanied by an increase in cell impedance. The increase in cell impedance in the battery pack will increase the heat generation of each cell in the battery pack. However, since the heat dissipation rate of the outer cells is greater than that of the inner cells, the difference in the maximum discharge temperature between the inner and outer cells increases, that is, the maximum temperature difference of the battery pack increases. Therefore, there is a correlation between the capacity retention rate and the maximum temperature difference of the battery pack. The capacity retention rate of the battery pack can characterize the health status of the battery pack. Therefore, the charging and discharging process of the battery pack can be controlled based on the maximum temperature difference of the battery pack to improve the cycle performance and expansion problem of the battery pack.

[0114] In this embodiment, since the capacity retention rate of the battery pack is related to the maximum discharge temperature and the maximum temperature difference, and the capacity retention rate can characterize the health status of the battery pack, the charging and discharging of the battery pack can be controlled based on the maximum discharge temperature and the maximum temperature difference. This improves the cycle performance of the battery pack, reduces safety risks, and achieves reasonable control of the charging and discharging process. Controlling the charging and discharging process based on the maximum discharge temperature and the maximum temperature difference only requires detecting the temperature of the cells during discharge, eliminating the need for high-precision detection components within the battery pack. This allows for reasonable control of the charging and discharging process at a lower cost.

[0115] In one possible implementation, after the battery pack temperature parameters meet the third condition, the first cell in the battery pack can be configured to reduce the upper limit voltage of charging, reduce the charging current, reduce the discharging current, or increase the lower limit voltage of discharging.

[0116] In this embodiment, since the first cell has the highest maximum discharge temperature in the battery pack, its capacity retention rate decays faster and its expansion rate increases faster than other cells. By reducing the upper limit voltage and charging current of the first cell and increasing the lower limit voltage of the first cell, the impact on the battery pack's range can be reduced while extending the battery pack's lifespan, thereby ensuring the user's experience.

[0117] Example 4

[0118] Figure 10 This is a flowchart of an electrochemical device control method provided in Embodiment 4 of this application. This method is used for charging and discharging control of a battery pack comprising multiple cells. Figure 10 As shown, the control method for this electrochemical device includes the following steps:

[0119] Step 1001: Obtain battery pack temperature parameters.

[0120] For details on obtaining battery pack temperature parameters, please refer to the description in step 701 of the aforementioned embodiment, which will not be repeated here.

[0121] Step 1002: Determine the battery pack health status corresponding to the battery pack temperature parameters according to the predetermined second correspondence.

[0122] As the battery pack capacity retention rate decreases, the impedance of the cells in the battery pack increases. The increased cell impedance will increase the heat generated during the charging and discharging process of the battery pack, which will affect the battery pack temperature parameters. Therefore, there is a correlation between the battery pack capacity retention rate and the battery pack temperature parameters. The battery pack capacity retention rate can characterize the health status of the battery pack. Thus, there is a specific correspondence between the battery pack temperature parameters and the battery pack health. Based on this correspondence, the battery pack health corresponding to the battery pack temperature parameters can be determined.

[0123] Battery pack health can indicate the health status of the battery pack, such as the battery pack's capacity retention rate.

[0124] The second correspondence can be a table that includes the correspondence between battery pack temperature parameters and battery pack health, or it can be a data processing model that determines battery pack health based on battery pack temperature parameters. This application does not limit this.

[0125] Step 1003: Determine the relationship between the battery pack health status and the third and fourth health status thresholds.

[0126] The third and fourth health thresholds are pre-set health thresholds, with the third threshold being higher than the fourth. When the battery pack's health is lower than the third threshold but higher than the fourth threshold, the overall health of the battery pack decreases, its capacity retention rate declines, and the battery pack expands. When the battery pack's health is lower than the fourth threshold, the health decline is significant, resulting in a noticeable degradation in the battery pack's range and power performance, leading to a poor customer experience.

[0127] Step 1004: If the battery pack health is less than the third health threshold and greater than the fourth health threshold, then configure at least one cell in the battery pack to perform at least one of the following: reduce the upper limit of charging voltage, reduce the charging current, reduce the discharging current, or increase the lower limit of discharging voltage.

[0128] If the battery pack health is less than the third health threshold but greater than the fourth health threshold, it indicates that the battery pack's health has deteriorated to a certain extent. In this case, reducing the upper limit voltage and / or charging current during the charging process and increasing the lower limit voltage during the discharging process can improve the battery pack's cycle performance and extend the lifespan of the cells.

[0129] Step 1005: If the battery pack health is less than the fourth health threshold, issue a warning message to indicate that the battery pack should be stopped.

[0130] If the battery pack health level is lower than the fourth health level threshold, it indicates that the battery pack's health has suffered significant degradation. The battery pack's capacity retention rate has decreased significantly, the battery pack has swelled noticeably, and the battery pack's range and functionality have declined significantly, affecting the user experience.

[0131] In this embodiment, since there is a correlation between battery pack temperature parameters and battery pack health, the battery pack health can be determined based on the battery pack temperature parameters. Therefore, the charging and discharging of the battery pack can be controlled based on the battery pack health, improving the battery pack's cycle performance, reducing safety risks, and achieving reasonable control of the battery pack's charging and discharging process. Determining battery pack health based on temperature parameters and then controlling the charging and discharging process based on that health only requires detecting the temperature of the battery cells within the battery pack, eliminating the need for high-precision detection components within the battery pack. This allows for reasonable control of the battery pack's charging and discharging process at a lower cost.

[0132] It should be noted that the methods for controlling the battery pack provided in Embodiments 3 and 4 above can refer to the methods for controlling the battery cells in Embodiments 1 and 2. The threshold range, threshold setting method, etc. can refer to the description in Embodiments 1 and 2, and will not be repeated here.

[0133] electronic devices

[0134] Figure 11 This is a schematic block diagram of an electronic device provided in an embodiment of this application. Specific embodiments of this application do not limit the specific implementation of the electronic device. Figure 11 As shown, the electronic device may include: a processor 1102, a communications interface 1104, a memory 1106, and a communication bus 1108. Wherein:

[0135] The processor 1102, communication interface 1104, and memory 1106 communicate with each other via communication bus 1108.

[0136] Communication interface 1104 is used to communicate with other electronic devices or servers.

[0137] The processor 1102 is used to execute program 1110, which can specifically execute the relevant steps in any of the aforementioned electrochemical device control method embodiments.

[0138] Specifically, program 1110 may include program code that includes computer operation instructions.

[0139] The processor 1102 may be a CPU, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application. The smart device may include one or more processors of the same type, such as one or more CPUs; or it may include processors of different types, such as one or more CPUs and one or more ASICs.

[0140] Memory 1106 is used to store program 1110. Memory 1106 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0141] Specifically, program 1110 can be used to cause processor 1102 to execute the electrochemical device control method in any of the foregoing embodiments.

[0142] The specific implementation of each step in procedure 1110 can be found in the corresponding steps and units described in any of the foregoing embodiments of the electrochemical device control method, and will not be repeated here. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the devices and modules described above can be referred to the corresponding process descriptions in the foregoing method embodiments, and will not be repeated here.

[0143] The electronic device of this application embodiment, because there is a correlation between the cell temperature parameters (battery pack temperature parameters) and the capacity retention rate of the cell (battery pack), and the capacity retention rate of the cell (battery pack) can characterize the health status of the cell (battery pack), can control the charging and discharging of the cell (battery pack) based on the cell temperature parameters (battery pack temperature parameters), thereby improving the cycle performance of the cell (battery pack), reducing safety risks, and achieving reasonable control of the charging and discharging process of the cell (battery pack). Controlling the charging and discharging process of the cell (battery pack) based on the cell temperature parameters (battery pack temperature parameters) only requires detecting the temperature of the cell, eliminating the need for high-precision detection components in the cell (battery pack), thus enabling reasonable control of the charging and discharging process of the cell (battery pack) at a lower cost.

[0144] Computer-readable storage media

[0145] This application also provides a computer-readable storage medium storing instructions for causing a machine to perform the electrochemical device control method of any of the above embodiments. Specifically, a system or apparatus equipped with a storage medium storing software program code that implements the functions of any of the above embodiments can be provided, and the computer (or CPU or MPU) of the system or apparatus can read and execute the program code stored in the storage medium.

[0146] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of this application.

[0147] Examples of storage media used to provide program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.

[0148] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0149] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0150] Computer program products

[0151] This application also provides a computer program product stored on a computer-readable medium and including computer-executable instructions, which, when executed, cause at least one processor to perform the electrochemical device control method of any of the above embodiments. It should be understood that the solutions in this embodiment have the corresponding technical effects in the above method embodiments, and will not be repeated here.

[0152] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0153] Furthermore, although the steps of the method in this application are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0154] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, mobile terminal, or network device, etc.) to execute the method according to the embodiments of this disclosure.

[0155] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the appended claims.

Claims

1. An electrochemical device control method for charging and discharging control of a single battery cell, the electrochemical device control method comprising: obtaining a battery cell temperature parameter, the battery cell temperature parameter comprising at least one of an initial discharging temperature, a maximum discharging temperature, an initial charging temperature, and a maximum charging temperature of the battery cell; configuring the battery cell to perform at least one of reducing a charging upper limit voltage, reducing a charging current, reducing a discharging current, or increasing a discharging lower limit voltage, if the battery cell temperature parameter satisfies a first condition; issuing warning information for indicating to limit use of the battery cell, if the battery cell temperature parameter satisfies a second condition; the first condition and the second condition being used to determine a health state of the battery cell according to the battery cell temperature parameter; the first condition comprising that a maximum discharging temperature growth rate of the battery cell is greater than a preset fifth threshold value and less than a preset sixth threshold value, and / or a maximum charging temperature growth rate of the battery cell is greater than a preset seventh threshold value and less than a preset eighth threshold value, wherein the fifth threshold value is less than the sixth threshold value, and the seventh threshold value is less than the eighth threshold value; the second condition comprising that the maximum discharging temperature growth rate of the battery cell is greater than the sixth threshold value, and / or the maximum charging temperature growth rate of the battery cell is greater than the eighth threshold value; the maximum discharging temperature growth rate being used to indicate a growth speed of a maximum discharging temperature of the battery cell with an increase in a cycle number of the battery cell, and the maximum charging temperature growth rate being used to indicate a growth speed of a maximum charging temperature of the battery cell with the increase in the cycle number of the battery cell. 2.The electrochemical device control method of claim 1, wherein the first condition comprises that a discharging temperature growth rate of the battery cell is greater than a preset first threshold value and less than a preset second threshold value, and / or a charging temperature growth rate of the battery cell is greater than a preset third threshold value and less than a preset fourth threshold value, wherein the first threshold value is less than the second threshold value, and the third threshold value is less than the fourth threshold value; and the second condition comprises that the discharging temperature growth rate of the battery cell is greater than the second threshold value, and / or the charging temperature growth rate of the battery cell is greater than the fourth threshold value. 3.An electrochemical device control method for charging and discharging control of a single battery cell, the electrochemical device control method comprising: obtaining a battery cell temperature parameter, the battery cell temperature parameter comprising at least one of an initial discharging temperature, a maximum discharging temperature, an initial charging temperature, and a maximum charging temperature of the battery cell; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ determining, according to a predetermined first correspondence relationship, a battery cell health degree corresponding to the battery cell temperature parameter, the battery cell health degree being used to indicate a health condition of the battery cell, the first correspondence relationship at least including a maximum discharge temperature growth rate of the battery cell and / or a maximum charge temperature growth rate of the battery cell and a capacity retention rate of the battery cell, the capacity retention rate being used to represent a health state of the battery cell, the maximum discharge temperature growth rate being used to indicate a growth speed of a maximum discharge temperature of the battery cell with an increase of a cycle number of the battery cell, and the maximum charge temperature growth rate being used to indicate a growth speed of a maximum charge temperature of the battery cell with the increase of the cycle number of the battery cell; if the battery cell health degree is less than a preset first health degree threshold and greater than a preset second health degree threshold, configuring the battery cell to perform at least one of reducing a charge upper limit voltage, reducing a charge current, reducing a discharge current, or increasing a discharge lower limit voltage, wherein the second health degree threshold is less than the first health degree threshold; if the battery cell health degree is less than the second health degree threshold, issuing warning information indicating to limit use of the battery cell.

4. An electrochemical device control method for performing charge and discharge control on a battery pack including a plurality of battery cells, the electrochemical device control method comprising: obtaining a battery pack temperature parameter including at least one of an initial discharge temperature, a maximum discharge temperature, an initial charge temperature, and a maximum charge temperature of at least two battery cells in the battery pack; if the battery pack temperature parameter satisfies a third condition, configuring at least one battery cell in the battery pack to perform at least one of reducing a charge upper limit voltage, reducing a charge current, reducing a discharge current, or increasing a discharge lower limit voltage; if the battery pack temperature parameter satisfies a fourth condition, issuing warning information indicating to stop use of the battery pack; the third condition and the fourth condition are used to determine a health state of the battery pack according to the battery pack temperature parameter; the third condition includes that a maximum discharge temperature of a first battery cell in the battery pack is greater than a preset ninth threshold and less than a preset tenth threshold, and / or a maximum temperature difference of the battery pack is greater than a preset eleventh threshold and less than a preset twelfth threshold, wherein the first battery cell is a battery cell with a maximum maximum discharge temperature in the battery pack determined based on the battery pack temperature parameter, a second battery cell is a battery cell with a minimum maximum discharge temperature in the battery pack determined based on the battery pack temperature parameter, the maximum temperature difference is equal to a difference between the maximum discharge temperatures of the first battery cell and the second battery cell, the ninth threshold is less than the tenth threshold, and the eleventh threshold is less than the twelfth threshold; the fourth condition includes that the maximum discharge temperature of the first battery cell is greater than the tenth threshold, and / or the maximum temperature difference is greater than the twelfth threshold.

5. The electrochemical device control method according to claim 4, wherein the configuring at least one battery cell in the battery pack to perform at least one of reducing a charge upper limit voltage, reducing a charge current, reducing a discharge current, or increasing a discharge lower limit voltage includes: The first battery cell is configured to reduce a charging upper limit voltage, reduce a charging current, reduce a discharging current, or increase a discharging lower limit voltage. 6.An electrochemical device control method for charging and discharging control of a battery pack including a plurality of battery cells, the electrochemical device control method comprising: obtaining a battery pack temperature parameter, the battery pack temperature parameter including at least one of an initial discharging temperature, a maximum discharging temperature, an initial charging temperature, and a maximum charging temperature of at least two battery cells in the battery pack; determining a battery pack health degree corresponding to the battery pack temperature parameter according to a predetermined second correspondence relationship, the battery pack health degree being used to indicate a health condition of the battery pack, the second correspondence relationship including at least a correspondence relationship between a maximum temperature difference of the battery pack and a capacity retention rate of the battery pack, the capacity retention rate being used to represent a health state of the battery pack, wherein the maximum temperature difference is equal to a difference between a maximum discharging temperature of a first battery cell and a maximum discharging temperature of a second battery cell, the first battery cell being a battery cell having a maximum maximum discharging temperature in the battery pack determined based on the battery pack temperature parameter, and the second battery cell being a battery cell having a minimum maximum discharging temperature in the battery pack determined based on the battery pack temperature parameter; if the battery pack health degree is less than a third preset health degree threshold and greater than a fourth preset health degree threshold, configuring at least one battery cell in the battery pack to perform at least one of reducing a charging upper limit voltage, reducing a charging current, reducing a discharging current, or increasing a discharging lower limit voltage, wherein the fourth health degree threshold is less than the third health degree threshold; if the battery pack health degree is less than the fourth health degree threshold, issuing warning information indicating to stop using the battery pack.

7. An electronic device comprising: a processor, a memory, a communication interface, and a communication bus, the processor, the memory, and the communication interface being in communication with each other through the communication bus; the memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform operations corresponding to the electrochemical device control method in any one of claims 1-6. 8.A computer readable storage medium, the computer readable storage medium storing a computer program, the computer program being executed by a processor to implement the electrochemical device control method in any one of claims 1-6.

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