Electrochemical device management method, charging device, electrochemical device, and electric device

Abstract

The embodiment of the present application provides a kind of electrochemical device management method, charging device, electrochemical device and electric equipment, comprising: in response to the temperature of electrochemical device reaches first temperature, the intermittent charging operation is carried out to electrochemical device, the data related to electrochemical device is obtained in intermittent charging operation, the lithium precipitation SOC of electrochemical device is determined based on the data related to electrochemical device;In response to lithium precipitation SOC less than or equal to first SOC threshold value, first charge-discharge cycle is carried out to electrochemical device at first temperature;In response to lithium precipitation SOC greater than first SOC threshold value, the temperature of electrochemical device is controlled to reduce to second temperature, second charge-discharge cycle is carried out to electrochemical device at second temperature.The embodiment of the present application can improve the safety of electrochemical device, prolong the service life of electrochemical device.

Description

Technical Field

[0001] This application relates to the field of electrochemical technology, and in particular to an electrochemical device management method, a charging device, an electrochemical device, and an electrical device. Background Technology

[0002] Lithium-ion batteries have many advantages, such as high energy density, long cycle life, high nominal voltage, low self-discharge rate, small size, and light weight, and are widely used in the consumer electronics field.

[0003] As the lithium-ion battery cycling or storage window gradually narrows—for example, lithium-ion batteries do not plaque lithium when charged with the rated current at the beginning of the cycle, but as the cycle progresses, continuing to charge with the rated current will cause lithium plaque to appear—it is necessary to reduce the charging current in a timely manner to ensure battery safety when a risk of lithium plaque is detected.

[0004] In related technologies, blind shaving is usually used when reducing the charging current, that is, reducing the current by a predetermined current value. However, this current reduction method is prone to under-shaving, and the electrochemical device still has the risk of lithium plating, which affects the safety of the electrochemical device and the user experience. Summary of the Invention

[0005] The purpose of this application is to provide a management method, charging device, electrochemical device, and electrical equipment for electrochemical devices, so as to reduce the risk of lithium plating during use and improve the safety of electrochemical devices. The specific technical solution is as follows:

[0006] A first aspect of this application provides an electrochemical device management method, comprising: in response to the temperature of the electrochemical device reaching a first temperature, performing an intermittent charging operation on the electrochemical device; acquiring data related to the electrochemical device during the intermittent charging operation; determining the lithium plating state-of-the-art (SOC) of the electrochemical device based on the data related to the electrochemical device; performing a first charge-discharge cycle on the electrochemical device at a first temperature in response to the lithium plating SOC being less than or equal to a first SOC threshold; or controlling the temperature of the electrochemical device to decrease to a second temperature in response to the lithium plating SOC being greater than the first SOC threshold, and performing a second charge-discharge cycle on the electrochemical device at the second temperature, wherein the second temperature is lower than the first temperature.

[0007] The beneficial effects of the embodiments of this application are as follows: By performing a first charge-discharge cycle on the electrochemical device at a first temperature, since the first temperature is higher than the second temperature, lithium plating during charging of the electrochemical device can be mitigated, the risk of lithium plating of the electrochemical device can be reduced, and the safety of the electrochemical device can be improved; by controlling the temperature of the electrochemical device to decrease to the second temperature and performing a second charge-discharge cycle on the electrochemical device at the second temperature, since the second temperature is lower than the first temperature, the risk of the electrochemical device in a high-temperature environment can be reduced, and the safety of the electrochemical device can be improved.

[0008] In one embodiment of this application, the step of performing a first charge-discharge cycle on the electrochemical device at a first temperature in response to the lithium plating SOC being less than or equal to a first SOC threshold includes: performing a first charge-discharge cycle on the electrochemical device at a first temperature in response to the lithium plating SOC being less than or equal to the first SOC threshold and the lithium plating SOC being greater than a second SOC threshold, which can slow down lithium plating in the electrochemical device and improve the service life of the electrochemical device.

[0009] In one embodiment of this application, the method further includes: controlling the electrochemical device to stop working in response to the lithium plating SOC being less than or equal to the second SOC threshold, wherein the second SOC threshold is less than the first SOC threshold; generating a prompt message to remind the user to replace the electrochemical device, thereby improving the user experience.

[0010] In one embodiment of this application, the method further includes reducing at least one of the charging voltage or charging current of the electrochemical device in response to the lithium plating SOC being less than or equal to a second SOC threshold and the lithium plating SOC being greater than a third SOC threshold. Embodiments of this application reduce the risk of lithium plating occurring in the electrochemical device due to continued operation at the current voltage and / or current, thereby improving the safety of the electrochemical device.

[0011] In one embodiment of this application, the step of reducing at least one of the charging voltage or charging current of the electrochemical device includes: i-1 reducing the current charging voltage of the electrochemical device to a first charging voltage at the first temperature by a first reduction rate, wherein the first charging voltage is the updated current charging voltage; and / or, i-2 reducing the current charging current of the electrochemical device to a first charging current at the first temperature by a second reduction rate, wherein the first charging current is the updated current charging current. Embodiments of this application reduce the risk of lithium plating occurring in the electrochemical device due to continued operation at the current voltage and / or current, thereby improving the safety of the electrochemical device.

[0012] In one embodiment of this application, the method further includes: ii-1 reducing the second SOC threshold and the third SOC threshold by a third reduction rate to obtain updated second SOC threshold and updated third SOC threshold; iii-1 responding to the electrochemical device completing a third charge-discharge cycle at the first temperature, performing an intermittent charging operation on the electrochemical device again, acquiring data related to the electrochemical device during the intermittent charging operation, determining the lithium plating SOC of the electrochemical device based on the data related to the electrochemical device, and determining the magnitude relationship between the lithium plating SOC and the updated second SOC threshold and the updated third SOC threshold; iv-1 when the lithium plating SOC is greater than the updated third SOC threshold and less than the updated second SOC threshold, repeating steps i-1 to iii-1 until the difference between the current charging voltage and the initial charging voltage of the electrochemical device is greater than a voltage difference threshold, generating a prompt message. This embodiment of the application can extend the service life of the electrochemical device and improve the user experience.

[0013] In one embodiment of this application, the method further includes: ii-2 In response to the electrochemical device completing a third charge-discharge cycle at the first temperature, performing an intermittent charging operation on the electrochemical device again, acquiring data related to the electrochemical device during the intermittent charging operation, determining the lithium plating SOC of the electrochemical device based on the data related to the electrochemical device, and determining the magnitude relationship between the lithium plating SOC and the second SOC threshold and the third SOC threshold; iii-2 When the lithium plating SOC is greater than the third SOC threshold and less than the second SOC threshold, repeating steps i-2 to ii-2 until the difference between the current charging current and the initial charging current of the electrochemical device is greater than the current difference threshold, generating a prompt message. This embodiment of the application can extend the service life of the electrochemical device and improve the user experience.

[0014] In one embodiment of this application, the data related to the electrochemical device includes the state of charge (SOC) and internal resistance of the electrochemical device. The intermittent charging operation includes multiple charging periods and multiple interrupted periods. The step of acquiring the data related to the electrochemical device during the intermittent charging operation and determining the lithium plating SOC of the electrochemical device based on the data related to the electrochemical device includes: during the intermittent charging operation, for each of the multiple interrupted periods, acquiring the SOC and internal resistance of the electrochemical device during the interrupted period; obtaining a first curve based on the acquired multiple SOCs of the electrochemical device and the multiple internal resistances of the electrochemical device corresponding to the multiple SOCs, wherein the first curve is a mapping curve corresponding to the SOC and internal resistance of the electrochemical device; and determining the lithium plating SOC of the electrochemical device based on the first curve.

[0015] In one embodiment of this application, the step of determining the lithium plating SOC of the electrochemical device based on the first curve includes at least one of method 1 or method 2, wherein: method 1 includes performing a first derivative on the first curve to obtain a second curve; and determining the SOC corresponding to the first point on the second curve where the slope is negative as the lithium plating SOC; method 2 includes performing a first derivative on the first curve to obtain a second curve; performing a second derivative on the second curve to obtain a third curve; and determining the SOC corresponding to the first point on the third curve where the ordinate is less than zero as the lithium plating SOC.

[0016] In one embodiment of this application, the intermittent charging operation includes multiple charging cycles, each charging cycle including a charging period and an intermittent period, during which the SOC of the electrochemical device increases by a unit magnitude. This embodiment of the application can perform intermittent charging operations on the electrochemical device in a timely manner to determine the lithium plating SOC of the electrochemical device, thereby reducing the risk of lithium plating.

[0017] In one embodiment of this application, the electrochemical device includes at least one of a lithium iron phosphate system electrochemical device, a lithium nickel cobalt manganese oxide system electrochemical device, or a lithium cobalt oxide system electrochemical device. Specifically, the electrochemical device is a lithium iron phosphate system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 15 seconds; the electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds; and the electrochemical device is a lithium cobalt oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds. This embodiment of the application more specifically performs intermittent charging operations on electrochemical devices of different systems, enabling more accurate determination of the lithium plating state of charge (SOC) for each system.

[0018] In one embodiment of this application, the method satisfies any one of conditions a) to c): a) the electrochemical device is a lithium iron phosphate system electrochemical device, the electrochemical device is at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds; b) the electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the electrochemical device is at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds; c) the electrochemical device is a lithium cobalt oxide system electrochemical device, the electrochemical device is at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds. This application embodiment more specifically performs intermittent charging operations on electrochemical devices in different temperature environments, and can more accurately obtain the lithium plating SOC of electrochemical devices of different systems.

[0019] In one embodiment of this application, before performing intermittent charging of the electrochemical device in response to the device reaching a first temperature, the method further includes heating the electrochemical device to the first temperature, wherein the first temperature is 30°C to 55°C. By heating the electrochemical device to the first temperature, embodiments of this application can improve the detection sensitivity of lithium plating SOC.

[0020] A second aspect of this application provides a charging device including a processor and a machine-readable storage medium storing machine-executable instructions that can be executed by the processor, wherein when the processor executes the machine-executable instructions, it implements the steps of the method described in the first aspect above.

[0021] A third aspect of this application provides an electrochemical device, including at least one heating element, a management unit, and a cooling device. The heating element heats the electrochemical device to a first temperature. The management unit performs intermittent charging operations on the electrochemical device when the temperature reaches the first temperature, acquires data related to the electrochemical device during the intermittent charging operations, determines the lithium plating state of charge (SOC) of the electrochemical device based on the data, and performs a first charge-discharge cycle on the electrochemical device at the first temperature in response to the lithium plating SOC being less than or equal to a first SOC threshold; or, in response to the lithium plating SOC being greater than the first SOC threshold, the cooling device lowers the temperature of the electrochemical device to a second temperature, and performs a second charge-discharge cycle on the electrochemical device at the second temperature, wherein the second temperature is lower than the first temperature. Embodiments of this application can reduce the risk of lithium plating in electrochemical devices and the risk in high-temperature environments, thereby improving the safety of the electrochemical device.

[0022] In one embodiment of this application, the management unit is specifically configured to perform a first charge-discharge cycle on the electrochemical device at a first temperature, wherein the lithium plating SOC is less than or equal to a first SOC threshold and the lithium plating SOC is greater than a second SOC threshold, the first temperature range being 30°C to 55°C. This embodiment of the application can slow down lithium plating in the electrochemical device and improve its service life.

[0023] In one embodiment of this application, the management unit is further configured to control the electrochemical device to stop working in response to the lithium plating SOC of the electrochemical device being less than or equal to the second SOC threshold, wherein the second SOC threshold is less than the first SOC threshold; and to generate a prompt message to remind the user to replace the electrochemical device, thereby improving the user experience.

[0024] In one embodiment of this application, the management unit is further configured to reduce at least one of the charging voltage or charging current of the electrochemical device in response to the lithium plating SOC being less than or equal to a second SOC threshold and the lithium plating SOC being greater than a third SOC threshold. Embodiments of this application reduce the risk of lithium plating occurring in the electrochemical device due to continued operation at the current voltage and / or current, thereby improving the safety of the electrochemical device.

[0025] In one embodiment of this application, the data related to the electrochemical device includes the state of charge (SOC) and internal resistance of the electrochemical device. The intermittent charging operation includes multiple charging periods and multiple interrupted periods. The management unit is specifically configured to: during the intermittent charging operation, for each of the multiple interrupted periods, acquire the SOC and internal resistance of the electrochemical device during the interrupted period; based on the acquired multiple SOCs of the electrochemical device and the multiple internal resistances of the electrochemical device corresponding to the multiple SOCs, obtain a first curve, the first curve being a mapping curve corresponding to the SOC and internal resistance of the electrochemical device; and based on the first curve, determine the lithium plating SOC of the electrochemical device.

[0026] In one embodiment of this application, the management unit is specifically used to perform a first-order derivative on the first curve to obtain a second curve; and to determine the SOC corresponding to the first point on the second curve where the slope is negative as the lithium plating SOC; or, to perform a first-order derivative on the first curve to obtain a second curve; to perform a second-order derivative on the second curve to obtain a third curve; and to determine the SOC corresponding to the first point on the third curve where the ordinate is less than zero as the lithium plating SOC.

[0027] In one embodiment of this application, the intermittent charging operation includes multiple charging cycles, each charging cycle including a charging period and an intermittent period, during which the SOC of the electrochemical device increases by a unit magnitude. This embodiment of the application can perform intermittent charging operations on the electrochemical device in a timely manner to determine the lithium plating SOC of the electrochemical device, thereby reducing the risk of lithium plating.

[0028] In one embodiment of this application, the electrochemical device includes at least one of a lithium iron phosphate system electrochemical device, a lithium nickel cobalt manganese oxide system electrochemical device, or a lithium cobalt oxide system electrochemical device. Specifically, the management unit is used for: when the electrochemical device is a lithium iron phosphate system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 15 seconds; when the electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds; when the electrochemical device is a lithium cobalt oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds. This embodiment of the application more specifically performs intermittent charging operations on electrochemical devices of different systems, enabling more accurate determination of the lithium plating state of charge (SOC) for different electrochemical devices.

[0029] In one embodiment of this application, the management unit is specifically used for at least one of the following a) to c): a) the electrochemical device is a lithium iron phosphate system electrochemical device, the electrochemical device is located at an ambient temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds; b) the electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the electrochemical device is located at an ambient temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds; c) the electrochemical device is a lithium cobalt oxide system electrochemical device, the electrochemical device is located at an ambient temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds. This embodiment of the application more specifically performs intermittent charging operations on electrochemical devices in different temperature environments, and can more accurately obtain the lithium plating SOC of electrochemical devices of different systems.

[0030] In one embodiment of this application, the heating element is made of at least one of nickel, nickel-aluminum alloy, copper, polyimide, silicone, or a positive temperature coefficient material.

[0031] The fourth aspect of this application provides an electrical device, including the electrochemical device provided in the third aspect above.

[0032] This application provides a method for managing an electrochemical device, a charging device, an electrochemical device, and an electrical device. Based on data related to the electrochemical device obtained during intermittent charging operations, the lithium plating state of the electrochemical device is determined. In response to the electrochemical device's lithium plating state of being less than or equal to a first state of being thresholded (SOC), indicating a slight risk of lithium plating, a first charge-discharge cycle is performed on the electrochemical device at a first temperature. Since the first temperature is higher than a second temperature, lithium plating during charging can be mitigated, reducing the risk of lithium plating and improving the safety of the electrochemical device. In response to the electrochemical device's lithium plating state of being greater than the first SOC threshold, indicating no risk of lithium plating, the temperature of the electrochemical device is controlled to decrease to a second temperature, and a second charge-discharge cycle is performed on the electrochemical device at the second temperature. Since the second temperature is lower than the first temperature, the risk of the electrochemical device operating in high-temperature environments can be reduced, improving the safety of the electrochemical device. Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above simultaneously. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of this application and the prior art, the accompanying drawings used in the embodiments and the prior art are briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0034] Figure 1 This is a flowchart illustrating an electrochemical device management method according to one embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the first curve of one embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the second curve according to one embodiment of this application;

[0037] Figure 4 This is a schematic diagram of the structure of an electrochemical device according to one embodiment of this application. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. All other technical solutions obtained by those skilled in the art based on the embodiments of this application fall within the scope of protection of this application.

[0039] It should be noted that, in the specific embodiments of this application, lithium-ion batteries are used as an example of electrochemical devices to explain this application, but the electrochemical devices of this application are not limited to lithium-ion batteries.

[0040] This application provides a method for managing an electrochemical device, such as... Figure 1 As shown, the method includes the following steps:

[0041] S101: In response to the temperature of the electrochemical device reaching a first temperature, perform intermittent charging operation on the electrochemical device, acquire data related to the electrochemical device during the intermittent charging operation, and determine the lithium plating SOC (State of Charge) of the electrochemical device based on the data related to the electrochemical device.

[0042] The implementing entity in this application embodiment can be a battery management system (BMS). During the operation of the electrochemical device, the battery management system can manage the electrochemical device, such as managing the charging and discharging processes of the electrochemical device. The battery management system can be integrated into the electrochemical device, or it can be independent of the electrochemical device but communicate with it.

[0043] In this embodiment, intermittent charging operation can refer to the process of intermittently charging the electrochemical device. Lithium plating state of charge (SOC) can refer to the SOC related to the lithium plating state of the electrochemical device. The management unit can perform intermittent charging operation on the electrochemical device; the management unit can be, for example, a microcontroller unit (MCU) in a battery management system.

[0044] In this embodiment, the battery management system can perform intermittent charging operations on the electrochemical device. In one example, during the operation of the electrochemical device, when the temperature of the electrochemical device reaches a first temperature, the management unit in the battery management system performs intermittent charging operations on the electrochemical device and performs lithium plating detection and analysis during the intermittent charging operation. Data related to the electrochemical device is acquired during the intermittent charging operation, and the state of charge (SOC) of the lithium plating of the electrochemical device is determined based on the data. The above-described process is for illustrative purposes only.

[0045] Data related to electrochemical devices can refer to data that reflects the state of the electrochemical device, including but not limited to data such as charging voltage, charging current, internal resistance, and state of charge (SOC).

[0046] This application does not impose any particular restrictions on the charging method in the intermittent charging operation. As long as the purpose of this application embodiment can be achieved, it can be constant voltage charging, constant current charging, constant current and constant voltage charging, or segmented constant current charging.

[0047] This application does not impose any particular limitation on the first temperature; the first temperature can be pre-set and is typically higher than room temperature. For example, the first temperature can be any temperature between 40°C and 50°C, such as 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, or 50°C. By performing intermittent charging of the electrochemical device at the first temperature, the detection sensitivity of lithium plating SOC can be improved.

[0048] The electrochemical device of this application embodiment may include at least one lithium-ion battery. When multiple lithium-ion batteries are included, these lithium-ion batteries may exist in the electrochemical device in series and / or parallel.

[0049] S102: In response to the lithium plating SOC being less than or equal to a first SOC threshold, the electrochemical device is subjected to a first charge-discharge cycle at a first temperature;

[0050] In this embodiment of the application, after the management unit in the battery management system performs intermittent charging operation on the electrochemical device, if the lithium plating state occupancy (SOC) of the electrochemical device is less than or equal to a first SOC threshold, the management unit, in response to this situation, performs a first charge-discharge cycle on the electrochemical device at a first temperature. The charge-discharge cycle in this embodiment of the application can refer to the process of the electrochemical device performing a charge-discharge-charge cycle during operation.

[0051] In the first charge-discharge cycle, the electrochemical device can be charged with a first charging current during the charging phase of the electrochemical device. This first charging current can be pre-set. Furthermore, the discharge current in the first charge-discharge cycle can be adapted to the electrical equipment; this application embodiment does not impose any limitation on this. The first charging current in this application embodiment is not particularly limited; for example, it can be any current between 0.1A and 3A, such as 0.1A, 0.2A, 0.3A, 0.5A, 0.7A, 1A, 1.5A, 2A, 2.5A, or 3A.

[0052] S103: In response to the lithium plating SOC being greater than the first SOC threshold, the temperature of the electrochemical device is controlled to decrease to a second temperature, and a second charge-discharge cycle is performed on the electrochemical device at the second temperature.

[0053] In this embodiment of the application, after the management unit in the battery management system performs intermittent charging of the electrochemical device, if the lithium plating state of the electrochemical device (SOC) exceeds a first SOC threshold, the management unit, in response to this situation, controls the temperature of the electrochemical device to decrease to a second temperature, and then performs a second charge-discharge cycle on the electrochemical device at the second temperature. For example, the second temperature can be any temperature between 25°C and 40°C, such as 25°C, 27°C, 29°C, 30°C, 31°C, 32°C, 33°C, 35°C, 37°C, 39°C, or 40°C. It is understood that the second temperature only needs to be lower than the first temperature. The temperature of the electrochemical device can be reduced using a cooling device; in one example, the electrochemical device can be cooled by controlling a cooling fan.

[0054] In the second charge-discharge cycle, the electrochemical device can be charged using a second charging current during the charging phase. This second charging current can be pre-set. Furthermore, the discharge current in the second charge-discharge cycle can be adapted to the electrical equipment; this application embodiment does not impose any limitation on this. The second charging current in this application embodiment is not particularly limited; for example, it can be any current between 0.1A and 3A, such as 0.1A, 0.2A, 0.3A, 0.5A, 0.7A, 1A, 1.5A, 2A, 2.5A, or 3A.

[0055] In one embodiment of this application, step S102 specifically involves: in response to the lithium plating SOC being less than or equal to a first SOC threshold and the lithium plating SOC being greater than a second SOC threshold, performing a first charge-discharge cycle on the electrochemical device at a first temperature.

[0056] In this embodiment, a first SOC threshold and a second SOC threshold can be set, wherein the first SOC threshold is greater than the second SOC threshold. Thus, after the management unit performs intermittent charging operations on the electrochemical device, when the lithium plating SOC of the electrochemical device meets the above conditions, performing a first charge-discharge cycle on the electrochemical device at a first temperature can slow down lithium plating and improve the lifespan of the electrochemical device.

[0057] In one embodiment of this application, the electrochemical device management method further includes: controlling the electrochemical device to stop operating in response to a lithium plating SOC being less than or equal to a second SOC threshold; and generating a prompt message. The second SOC threshold is less than a first SOC threshold.

[0058] When the lithium plating SOC is less than or equal to the second SOC threshold, it indicates that the lithium plating SOC of the electrochemical device has become very small, and the performance of the electrochemical device has degraded significantly. Therefore, the electrochemical device can be stopped and the user can be prompted to replace it or scrap it. This allows the user to be promptly informed that the electrochemical device can no longer be used normally due to performance degradation, thus improving the user experience.

[0059] In one embodiment of this application, the electrochemical device management method further includes: in response to a lithium plating SOC being less than or equal to a second SOC threshold and a lithium plating SOC being greater than a third SOC threshold, reducing at least one of the charging voltage or charging current of the electrochemical device.

[0060] This application embodiment can set a second SOC threshold and a third SOC threshold, wherein the second SOC threshold is greater than the third SOC threshold. Thus, after the management unit performs intermittent charging of the electrochemical device, when the lithium plating SOC of the electrochemical device meets the above conditions, it reduces the charging voltage of the electrochemical device, or reduces the charging current of the electrochemical device, or simultaneously reduces both the charging voltage and charging current of the electrochemical device. This reduces the risk of lithium plating occurring due to continued operation of the electrochemical device at the current voltage and / or current, and improves the safety of the electrochemical device.

[0061] The aforementioned SOC threshold can be a pre-set threshold. The SOC threshold can be stored in advance in a storage medium connected to the electrochemical device. The SOC threshold is generally set based on the SOC of an electrochemical device sample from the same system when lithium plating occurs. For example, the SOC threshold can be set to the SOC corresponding to the occurrence of lithium plating in an electrochemical device sample. Different SOC thresholds are typically set for electrochemical devices with different systems. For the same electrochemical device sample, the measured SOC corresponding to the occurrence of lithium plating will also differ at different charging rates and / or ambient temperatures.

[0062] In one embodiment, the step of reducing at least one of the charging voltage or charging current of the electrochemical device includes:

[0063] Step i-1 reduces the current charging voltage of the electrochemical device to a first charging voltage at a first temperature by a first reduction rate, the first charging voltage being the updated current charging voltage; and / or,

[0064] Step i-2 reduces the current charging current of the electrochemical device to a first charging current at a second reduction rate at a first temperature, where the first charging current is the updated current charging current.

[0065] Embodiments of this application can reduce the charging voltage and / or charging current of an electrochemical device. In one example, when reducing the charging voltage of the electrochemical device, the current charging voltage can be reduced by a first decrease at a first temperature to obtain a first voltage, which is the updated current charging voltage. The first decrease can be from 0.01V to 1V, for example, 0.01V, 0.025V, 0.05V, 0.1V, or 1V.

[0066] In another example, when reducing the charging current of the electrochemical device, the current charging current can be reduced by a second reduction at a first temperature to obtain an updated current charging current. The second reduction can be the product of the battery's rated capacity and a first coefficient, which is between 0.05 and 0.15, for example, 0.05, 0.08, 0.1, 0.12, or 0.15. Of course, both the charging voltage and charging current of the electrochemical device can also be reduced simultaneously.

[0067] In one embodiment, the electrochemical device management method of this application may further include:

[0068] Step ii-1 reduces the second SOC threshold and the third SOC threshold by the third reduction rate respectively, to obtain the updated second SOC threshold and the updated third SOC threshold;

[0069] Step iii-1 In response to the completion of the third charge-discharge cycle of the electrochemical device at the first temperature, the electrochemical device is subjected to intermittent charging operation again. During the intermittent charging operation, data related to the electrochemical device is acquired. Based on the data related to the electrochemical device, the lithium plating SOC of the electrochemical device is determined, and the relationship between the lithium plating SOC and the updated second SOC threshold and the updated third SOC threshold is determined.

[0070] Step iv-1: When the lithium plating SOC is greater than the updated third SOC threshold and less than the updated second SOC threshold, repeat steps i-1 to iii-1 until the difference between the current charging voltage and the initial charging voltage of the electrochemical device is greater than the voltage difference threshold, and generate a prompt message. In this embodiment, steps i-1 to iii-1 include: step i-1, step ii-1, and step iii-1.

[0071] In this embodiment, after reducing the charging voltage, the second and third SOC thresholds can be reduced by a third reduction rate to obtain updated second and third SOC thresholds. Thus, as the electrochemical device is used, after completing the third charge-discharge cycle at the first temperature, it triggers intermittent charging again and performs lithium plating detection. When the lithium plating SOC of the electrochemical device is greater than the updated third SOC threshold but less than the updated second SOC threshold, the current charging voltage is reduced again by the first reduction rate, and so on, thereby extending the lifespan of the electrochemical device. The third reduction rate can be 1% to 10%, for example, 1%, 2.5%, 5%, or 10%.

[0072] In the third charge-discharge cycle, the electrochemical device can be charged using a third charging current during the charging phase. This third charging current can be pre-set. Furthermore, the discharge current in the third charge-discharge cycle can be adapted to the electrical equipment; this application embodiment does not impose any limitations on this. The third charging current in this application embodiment is not particularly limited; for example, it can be any current between 0.1A and 3A, such as 0.1A, 0.2A, 0.3A, 0.5A, 0.7A, 1A, 1.5A, 2A, 2.5A, or 3A.

[0073] As the charging voltage decreases, when the difference between the current charging voltage and the initial charging voltage of the electrochemical device exceeds a voltage difference threshold, it indicates significant performance degradation of the electrochemical device. This prompts the user to replace the device or even scrap it, allowing them to be promptly informed that the device is no longer usable due to performance degradation, thus improving the user experience. The aforementioned voltage difference threshold can be between 0.01V and 1V, for example, 0.01V, 0.1V, 0.5V, or 1V. The initial charging voltage can be the initial full charge voltage, i.e., the voltage at 100% SOC of the electrochemical device.

[0074] In one embodiment, the electrochemical device management method of this application may further include:

[0075] In step ii-2, in response to the completion of the third charge-discharge cycle of the electrochemical device at the first temperature, the electrochemical device is subjected to intermittent charging operation again. During the intermittent charging operation, data related to the electrochemical device is acquired. Based on the data related to the electrochemical device, the lithium plating SOC of the electrochemical device is determined, and the relationship between the lithium plating SOC and the second SOC threshold and the third SOC threshold is determined.

[0076] Step iii-2: When the lithium plating SOC is greater than the third SOC threshold and less than the second SOC threshold, repeat steps i-2 to ii-2 until the difference between the current charging current and the initial charging current of the electrochemical device is greater than the current difference threshold. A prompt message is generated to remind the user to replace the electrochemical device or to scrap it. This allows the user to be promptly informed that the electrochemical device is no longer usable due to performance degradation, improving the user experience. In this embodiment, steps i-2 to ii-2 include: step i-2 and step ii-2.

[0077] In this embodiment of the application, after reducing the charging current, as the electrochemical device is used, after the electrochemical device completes the second charge-discharge cycle at the first temperature, it triggers intermittent charging operation again and performs lithium plating detection. When the lithium plating SOC of the electrochemical device is greater than the third SOC threshold and less than the second SOC threshold, the current charging current is reduced again by the second reduction rate, and so on, thereby extending the service life of the electrochemical device.

[0078] As the charging current decreases, when the difference between the current charging current and the initial charging current of the electrochemical device exceeds a current difference threshold, it indicates significant performance degradation of the electrochemical device. This prompts the user to replace the electrochemical device or to scrap it. This allows users to be promptly informed that the electrochemical device is no longer usable due to performance degradation, improving the user experience. The aforementioned current difference threshold is the product of a second coefficient and the battery's rated capacity, where the second coefficient ranges from 0.1 to 0.5, for example, 0.1, 0.2, 0.25, 0.4, or 0.5.

[0079] In one embodiment of this application, the data associated with the electrochemical device include the state of charge (SOC) and internal resistance of the electrochemical device, and the intermittent charging operation includes multiple charging periods and multiple interruption periods.

[0080] Intermittent charging operation can refer to the process of intermittently charging an electrochemical device. Data related to the electrochemical device can refer to data that reflects the state of the electrochemical device. The state of charge (SOC) of lithium plating in the electrochemical device is determined in the following way:

[0081] Step A: During the intermittent charging operation, for each of the multiple intermittent periods, obtain the SOC and internal resistance of the electrochemical device during that intermittent period;

[0082] In intermittent charging operations, the internal resistance of the electrochemical device can be determined based on the detected charging voltage and charging current. A voltage-SOC relationship table can be pre-stored in the BMS, recording the SOC of the electrochemical device corresponding to different charging voltages; for example, 4.2V corresponds to 85% SOC, and 4.3V corresponds to 90% SOC. Therefore, the SOC of the electrochemical device can be determined based on the charging voltage and the voltage-SOC relationship table.

[0083] Step B: Based on the multiple SOCs of the obtained electrochemical device and the multiple internal resistances of the electrochemical device corresponding to the multiple SOCs, the first curve is obtained;

[0084] In this embodiment of the application, after obtaining the SOC and internal resistance during multiple intermittent periods of the electrochemical device, multiple data pairs consisting of SOC and internal resistance can be obtained, which can be referenced. Figure 2 We can use the SOC of the electrochemical device as the abscissa and the internal resistance of the electrochemical device as the ordinate, fill the points represented by these data pairs into the coordinate system, and obtain the first curve after fitting. The first curve represents the mapping curve between the SOC and the internal resistance of the electrochemical device.

[0085] It is understandable that the more intensive the acquisition of SOC and internal resistance data for the electrochemical device, the more data pairs are obtained, resulting in a more detailed first curve. In this embodiment, it is not necessarily required to acquire SOC and internal resistance data for all interruptions. That is, "each interruption" can refer to any interruption during which SOC and internal resistance data have already been acquired, rather than requiring the acquisition of SOC and internal resistance data for all interruptions. As long as a sufficient number of SOC and internal resistance data points are acquired to obtain the first curve, it is acceptable. The process of curve fitting using data is well known to those skilled in the art, and the comparison of embodiments in this application does not impose specific limitations.

[0086] Step C: Based on the first curve, determine the state of lithium plating (SOC) of the electrochemical device.

[0087] The first curve represents the mapping relationship between the SOC and internal resistance of the electrochemical device. The lithium plating SOC of the electrochemical device can be determined based on the first curve.

[0088] The aforementioned lithium plating SOC may not be measured in real time, but rather obtained from the charging voltage obtained during intermittent charging operations and a voltage-SOC relationship table, which can be pre-stored in the storage medium of the battery management system.

[0089] In one embodiment, the process of determining the lithium plating state of the electrochemical device based on the first curve can be method 1, which includes:

[0090] i: Take the first derivative of the first curve to obtain the second curve;

[0091] like Figure 3 As shown, the second curve is obtained by taking the first derivative of the first curve. This second curve represents the rate of change of the internal resistance of the electrochemical device with SOC.

[0092] ii: Determine the SOC corresponding to the point where the slope of the second curve first appears negative as the lithium plating SOC.

[0093] The second curve represents the rate of change of internal resistance with SOC. When the rate of change does not show an abnormal decrease in the flat region of the curve, it indicates that no active lithium has been deposited. When the rate of change shows an abnormal decrease in the flat region of the curve, it is because active lithium has been deposited on the surface of the negative electrode and is in contact with the negative electrode. This is equivalent to a lithium metal device being connected in parallel with the graphite part of the negative electrode, which reduces the impedance of the entire negative electrode. Therefore, the impedance of the electrochemical device shows an abnormal decrease when active lithium is deposited, and correspondingly, the flat region of the second curve shows an abnormal decrease. (Reference) Figure 3Point B marks the first time the slope of the second curve becomes negative. This means that the flat area of ​​the second curve at point B shows an abnormal decrease for the first time, indicating that the electrochemical device is showing a tendency to or has already undergone lithium plating at point B. Therefore, the State of Charge (SOC) corresponding to point B can be determined as the lithium plating SOC. Based on the relationship between the lithium plating SOC and the SOC threshold, timely protection measures can be taken for the electrochemical device, improving its operational safety. Steps A to C above are only used to illustrate the order of the steps, not to limit their execution.

[0094] In one implementation, the process of determining the lithium plating state of the electrochemical device based on the first curve can be method 2, which includes:

[0095] i': Take the first derivative of the first curve to obtain the second curve;

[0096] This step is the same as step i in method 1, and will not be repeated here.

[0097] ii': Taking the second derivative of the second curve yields the third curve;

[0098] The second curve can also be differentiated by its second order to obtain the third curve. It can be understood that the third curve is the second-order differential curve of the second curve.

[0099] iii': Determine the SOC corresponding to the point where the ordinate of the third curve first appears to be less than zero as the lithium plating SOC.

[0100] If the ordinate of the third curve is less than zero, the SOC corresponding to the first point where the ordinate of the third curve is less than zero is determined as the lithium plating SOC. In this embodiment, the ordinate of the third curve is the second-order differential internal resistance, and the abscissa of the third curve is the state of charge.

[0101] Intermittent charging operation can refer to the process of intermittently charging an electrochemical device. In one embodiment, intermittent charging operation may include multiple charging cycles, each charging cycle comprising a charging period and an intermittent period, during which the state of charge (SOC) of the electrochemical device increases by a unit increment. That is, the SOC of the electrochemical device is increased by a certain increment during each charging period, for example, by 0.5%, 1%, 5%, or 10% of the SOC during each charging period.

[0102] The intermittent charging operation of this application embodiment includes multiple charging cycles, each charging cycle including a charging period and an interruption period. Exemplarily, a first charging period and a first interruption period form a first charging cycle, a second charging period and a second interruption period form a second charging cycle, a third charging period and a third interruption period form a third charging cycle, and so on. It is understood that a charging cycle is a continuous time period.

[0103] In one implementation, the intermittent charging operation can be specifically described as follows: For any one of multiple charging cycles, the electrochemical device is charged at a first moment until the State of Charge (SOC) of the electrochemical device increases by a unit magnitude, at which point charging stops, until a third moment. The moment at which charging stops is the second moment, and the time interval between the third moment and the second moment is the duration of the intermittent period. During the intermittent period, the electrochemical device can be in a state of neither charging nor discharging, i.e., a static state.

[0104] For example, if the electrochemical device is charged at time T1 until the state of charge (SOC) of the electrochemical device increases by a unit magnitude, and then the charging stops, the time when the charging stops is time T2; starting from time T2, the electrochemical device is left to stand, and the time when the standing ends is time T3.

[0105] This application embodiment, by performing intermittent charging operation on the electrochemical device, can obtain data related to the electrochemical device during the intermittent charging operation. Based on this data, the lithium plating state occupancy (SOC) of the electrochemical device can be determined, which makes it easier to take protective measures for the electrochemical device in the future.

[0106] The electrochemical device in this application includes at least one of a lithium iron phosphate system, a lithium nickel cobalt manganese oxide system, or a lithium cobalt oxide system. Generally, in intermittent charging operations, different electrochemical systems correspond to different unit amplitudes and different intermittent periods. Based on this:

[0107] In one embodiment, the electrochemical device is a lithium iron phosphate system electrochemical device, with a unit amplitude ranging from 0.5% to 10% and an intermittent period duration ranging from 1 second to 15 seconds.

[0108] In one embodiment, the electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, with a unit amplitude ranging from 0.5% to 10% and an intermittent period duration ranging from 1 second to 30 seconds.

[0109] In one embodiment, the electrochemical device is a lithium cobalt oxide system electrochemical device, with a unit amplitude ranging from 0.5% to 10% and an intermittent period duration ranging from 1 second to 30 seconds.

[0110] This application embodiment sets different unit amplitudes and intermittent periods for different electrochemical devices, enabling more targeted intermittent charging operations for different electrochemical devices, and thus more accurately obtaining the lithium plating SOC of different electrochemical devices.

[0111] Generally speaking, in intermittent charging operations, for the same electrochemical device system, different temperature conditions will correspond to different unit amplitudes and different durations of interruptions. Based on this:

[0112] In one embodiment, the electrochemical device is a lithium iron phosphate system electrochemical device, the electrochemical device is operated at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds.

[0113] In the embodiments of this application, the positive electrode of the lithium iron phosphate system electrochemical device may also include other positive electrode active materials, but lithium iron phosphate is the main material. For example, lithium iron phosphate accounts for any one of 51%, 60%, 70%, 80%, 90%, or 98% of the total mass of the positive electrode active material.

[0114] In one embodiment, the electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the electrochemical device is operated at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds.

[0115] In the embodiments of this application, the positive electrode of the lithium nickel cobalt manganese oxide system electrochemical device may also include other positive electrode active materials, but lithium nickel cobalt manganese oxide is the main material. For example, lithium nickel cobalt manganese oxide accounts for any of the following values ​​of the total mass of the positive electrode active material: 51%, 60%, 70%, 80%, 90%, and 98%.

[0116] In one embodiment, the electrochemical device is a lithium cobalt oxide system electrochemical device, the electrochemical device is operated at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds.

[0117] In the embodiments of this application, the positive electrode of the lithium cobalt oxide system electrochemical device may also include other positive electrode active materials, but lithium cobalt oxide is the main material. For example, lithium cobalt oxide accounts for any of the following values ​​of the total mass of the positive electrode active material: 51%, 60%, 70%, 80%, 90%, and 98%.

[0118] This application embodiment sets different unit amplitudes and intermittent durations for electrochemical devices in the same system at different temperatures, enabling more targeted intermittent charging operations for electrochemical devices in different temperature environments, and thus more accurately obtaining the lithium plating SOC of electrochemical devices in different systems.

[0119] In one implementation, the step of generating the first curve includes:

[0120] Step a: Obtain the first voltage, first current, and first SOC of the electrochemical device at a second time point, and the second voltage and second current of the electrochemical device at a third time point;

[0121] The second moment is the moment when charging stops. The voltage, current, and state of charge (SOC) of the electrochemical device at the second moment can be obtained, namely the first voltage, the first current, and the first SOC, denoted as V1, I1, and SOC1, respectively. Similarly, the voltage and current of the electrochemical device at the third moment can be obtained, namely the second voltage and the second current, denoted as V2 and I2, respectively.

[0122] Step b: Calculate the voltage and current changes of the electrochemical device during the intermittent period.

[0123] The duration of the interruption is the time interval between the third moment and the second moment. The voltage change of the electrochemical device during the interruption is ΔV, where ΔV = V2 - V1. The current change of the electrochemical device during the interruption is ΔI, where ΔI = I2 - I1.

[0124] Step c: Calculate the first internal resistance of the electrochemical device during the intermittent period based on the voltage change value and the current change value, and use the first internal resistance and the first SOC as one of the data pairs of the first curve, wherein the data pair is the correspondence between internal resistance and SOC.

[0125] The first internal resistance of the electrochemical device during the intermittent period is R1, where R1 = ΔV / ΔI. R1 and SOC1 are used as one data pair for the first curve.

[0126] Multiple data pairs can be obtained by using the same method described above.

[0127] Step d: Generate the first curve based on the calculated data pairs.

[0128] Using the state of charge (SOC) of the electrochemical device as the abscissa and the internal resistance of the electrochemical device as the ordinate, the points represented by these data pairs are filled into a coordinate system, and a first curve is obtained after fitting. In this embodiment of the application, after obtaining the first curve, the lithium plating SOC of the electrochemical device can be determined through the first curve, allowing for timely diversion and heating of the electrochemical device, thereby improving its service life.

[0129] This application provides an electrochemical device management method that, based on data related to the electrochemical device obtained during intermittent charging operations, determines the lithium plating state of the electrochemical device (SOC). If the SOC is less than or equal to a first SOC threshold, indicating a slight risk of lithium plating, a first charge-discharge cycle is performed on the electrochemical device at a first temperature. Since the first temperature is higher than a second temperature, lithium plating during charging can be mitigated, reducing the risk of lithium plating and improving the safety of the electrochemical device. If the SOC is greater than the first SOC threshold, indicating no risk of lithium plating, the temperature of the electrochemical device is controlled to decrease to a second temperature, and a second charge-discharge cycle is performed on the electrochemical device at the second temperature. Since the second temperature is lower than the first temperature, the risk of lithium plating in high-temperature environments can be reduced, improving the safety of the electrochemical device.

[0130] This application also provides a charging device, including a processor and a machine-readable storage medium. The machine-readable storage medium stores machine-executable instructions that can be executed by the processor. When the processor executes the machine-executable instructions, it implements the electrochemical device management method described in any of the above embodiments.

[0131] In one example, reference Figure 4 The charging device includes a housing 1 and a heating element 2 (as shown by the slanted fill in the figure). The housing 1 can accommodate a lithium-ion battery 3, and the heating element 2 is positioned between the housing 1 and the lithium-ion battery 3. Specifically, the heating element 2 can be located on the inner wall of the housing 1 to increase the heating and heat dissipation areas. An opening is located at the top of the housing 1, and a cooling device 4, such as a fan, is installed at the opening. The heating element 2 can also be equipped with a temperature control switch. When the temperature drops below a first temperature, the temperature control switch closes, energizing the heating element 2 and initiating heating, thus raising the temperature of the lithium-ion battery. Alternatively, the charging device can also be equipped with a temperature sensor. When the temperature sensor detects that the temperature is below the first temperature, it sends a signal to the management unit of the charging device. Upon receiving the signal, the management unit controls the heating element 2 to begin heating. During cooling, the management unit controls the heating element 1 to de-energize, and simultaneously activates the cooling device 4 to dissipate heat from the lithium-ion battery, thereby cooling the lithium-ion battery. In this case, the heating element 1 also serves a heat dissipation function.

[0132] This application also provides an electrochemical device, including at least one heating element, a management unit, and a cooling device. The heating element is used to heat the electrochemical device to a first temperature; the management unit is used to perform intermittent charging operation on the electrochemical device when the temperature of the electrochemical device reaches the first temperature, acquire data related to the electrochemical device during the intermittent charging operation, determine the lithium plating state of the electrochemical device based on the data related to the electrochemical device; and, in response to the lithium plating state of the electrochemical device being less than or equal to a first state of the ...

[0133] In one example, reference Figure 4 The electrochemical device includes a housing 1 and a lithium-ion battery 3, which is disposed inside the housing 1. A heating element 2 is positioned between the housing 1 and the lithium-ion battery 3. Specifically, the heating element 2 can be located on the inner wall of the housing 1 to increase the heating and heat dissipation areas. Furthermore, the electrochemical device is equipped with a heat dissipation management system (BMS). An opening is located at the top of the housing 1, and a cooling device 4, such as a fan, is installed at the opening. The heating element 2 can also be equipped with a temperature control switch. When the temperature drops below a first temperature, the temperature control switch closes, energizing the heating element 2 and initiating heating, thus raising the temperature of the electrochemical device. Alternatively, the electrochemical device can also be equipped with a temperature sensor. When the temperature sensor detects that the temperature is below the first temperature, it sends a signal to the management unit of the BMS. Upon receiving the signal, the management unit controls the heating element 2 to begin heating. During cooling, the management unit de-energizes the heating element 1 and simultaneously activates the cooling device 4 to dissipate heat from the inside of the electrochemical device, thereby cooling the device. In this case, the heating element 1 also serves a heat dissipation function.

[0134] In one implementation, the management unit is specifically used for:

[0135] In response to a lithium plating SOC being less than or equal to a first SOC threshold and a lithium plating SOC being greater than a second SOC threshold, the electrochemical device is subjected to a first charge-discharge cycle at a first temperature, the first temperature range being 30°C to 55°C.

[0136] In one embodiment, the management unit is further configured to: control the electrochemical device to stop operating in response to the lithium plating SOC of the electrochemical device being less than or equal to a second SOC threshold, wherein the second SOC threshold is less than a first SOC threshold; and generate a prompt message.

[0137] In one embodiment, the management unit is further configured to: reduce at least one of the charging voltage or charging current of the electrochemical device in response to the lithium plating SOC being less than or equal to a second SOC threshold and the lithium plating SOC being greater than a third SOC threshold.

[0138] In one embodiment, data related to the electrochemical device includes the state of charge (SOC) and internal resistance of the electrochemical device. The intermittent charging operation includes multiple charging periods and multiple interruptions. The management unit is specifically used for:

[0139] During intermittent charging operation, for each of the multiple intermittent periods, the SOC and internal resistance of the electrochemical device during the intermittent period are obtained. Based on the multiple SOCs of the electrochemical device and the multiple internal resistances of the electrochemical device corresponding to the multiple SOCs, a first curve is obtained. The first curve is a mapping curve corresponding to the SOC and internal resistance of the electrochemical device. Based on the first curve, the lithium plating SOC of the electrochemical device is determined.

[0140] In one implementation, the management unit is specifically used to: perform a first-order derivative on the first curve to obtain a second curve; and determine the SOC corresponding to the first point on the second curve where the slope is negative as the lithium plating SOC; or, perform a first-order derivative on the first curve to obtain a second curve; perform a second-order derivative on the second curve to obtain a third curve; and determine the SOC corresponding to the first point on the third curve where the ordinate is less than zero as the lithium plating SOC.

[0141] In one embodiment, the intermittent charging operation includes multiple charging cycles, each charging cycle including a charging period and an intermittent period, during which the SOC of the electrochemical device increases by a unit magnitude.

[0142] In one embodiment, the electrochemical device includes at least one of a lithium iron phosphate system electrochemical device, a nickel-cobalt-manganese oxide system electrochemical device, or a lithium cobalt oxide system electrochemical device, wherein the management unit is specifically used for:

[0143] The electrochemical device is a lithium iron phosphate system electrochemical device, with a unit amplitude ranging from 0.5% to 10% and an intermittent duration ranging from 1 second to 15 seconds;

[0144] The electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, with a unit amplitude ranging from 0.5% to 10% and an intermittent duration ranging from 1 second to 30 seconds;

[0145] The electrochemical device is a lithium cobalt oxide system electrochemical device with a unit amplitude ranging from 0.5% to 10% and an intermittent duration ranging from 1 second to 30 seconds.

[0146] In one implementation, the management unit is specifically used for at least one of the following a) to c):

[0147] a) The electrochemical device is a lithium iron phosphate system electrochemical device, the electrochemical device is in an ambient temperature of 30°C to 55°C, the unit amplitude range is 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds;

[0148] b) The electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device. The electrochemical device is in an ambient temperature of 30°C to 55°C, the unit amplitude range is 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds.

[0149] c) The electrochemical device is a lithium cobalt oxide system electrochemical device, the electrochemical device is in an ambient temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds.

[0150] In one embodiment, the heating element is made of at least one of nickel, nickel-aluminum alloy, copper, polyimide (PI), silicone, or PTC (Positive Temperature Coefficient) material.

[0151] This application also provides an electrical device, including the electrochemical device of the above-described embodiments.

[0152] Machine-readable storage media may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0153] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0154] For the embodiments of electrochemical devices / electrical equipment, since they are basically similar to the method embodiments, the description is relatively simple, and relevant parts can be found in the description of the method embodiments.

[0155] Preparation Example 1

[0156] Preparation of lithium-ion batteries based on nickel-cobalt-manganese oxide system :

[0157] Preparation of the positive electrode sheet: Lithium nickel cobalt manganese oxide (LCM), acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 94:3:3. N-methylpyrrolidone (NMP) was then added as a solvent to prepare a slurry with a solid content of 75 wt%, and the mixture was stirred evenly. The slurry was uniformly coated onto one surface of a 12 μm thick aluminum foil, dried at 90°C, and cold-pressed to obtain a positive electrode sheet with a 100 μm thick positive active material layer. The above steps were repeated on the other surface of the same positive electrode sheet to obtain a positive electrode sheet with positive active material layers coated on both sides. The positive electrode sheet was cut to a size of 74 mm × 867 mm and tabs were welded on for later use.

[0158] Preparation of the negative electrode sheet: Artificial graphite, acetylene black, styrene-butadiene rubber, and sodium carboxymethyl cellulose (NCM) were mixed in a mass ratio of 96:1:1.5:1.5. Deionized water was then added as a solvent to prepare a slurry with a solid content of 70 wt%, and the mixture was stirred evenly. The slurry was uniformly coated onto one surface of an 8 μm thick copper foil, dried at 110°C, and cold-pressed to obtain a single-sided negative electrode sheet with a 150 μm thick negative active material layer. The coating process was repeated on the other surface of the same negative electrode sheet to obtain a double-sided negative electrode sheet. The negative electrode sheet was cut to a size of 74 mm × 867 mm and tabs were welded on for later use.

[0159] Preparation of the separator: A porous polyethylene (PE) film with a thickness of 15 μm was used as the separator.

[0160] Preparation of electrolyte: In an environment with a water content of less than 10 ppm, non-aqueous organic solvents ethylene carbonate (EC), propylene carbonate (PC), and diethyl carbonate (DEC) were mixed in a mass ratio of 1:1:1. Then, lithium hexafluorophosphate (LiPF6) was added to the non-aqueous organic solvents, dissolved, and mixed evenly to obtain the electrolyte, wherein the concentration of LiPF6 was 1.15 mol / L.

[0161] Preparation of lithium-ion batteries: The positive electrode, separator, and negative electrode prepared above are stacked in sequence, with the separator positioned between the positive and negative electrode to provide isolation. The electrode assembly is then wound to obtain the electrode assembly. The electrode assembly is placed in an aluminum-plastic film packaging bag and dehydrated at 80°C. A prepared electrolyte is then injected, and the battery undergoes vacuum sealing, settling, formation, and shaping processes to obtain a lithium-ion battery with a rated capacity of 5Ah.

[0162] Example 1

[0163] <Detection of Lithium Plating SOC>

[0164] Take the lithium-ion battery prepared in Preparation Example 1 and place it in the following container. Figure 4 In the charging device shown, the heating element is activated to heat the lithium-ion battery. When the surface temperature of the lithium-ion battery reaches the first temperature of 45°C, the electrochemical device is intermittently charged. After lithium plating detection, the lithium plating state of charge (SOC) is obtained.

[0165] <Lithium-ion battery protection operation>

[0166] If the lithium plating SOC is greater than the first SOC threshold, the measured lithium plating SOC is recorded as the first critical lithium plating SOC. The cooling device is started. When the temperature of the lithium-ion battery surface reaches below 25°C, the lithium-ion battery can be used normally, and the current cycle number of the lithium-ion battery is recorded.

[0167] If the second SOC threshold < lithium plating SOC ≤ the first SOC threshold, the measured lithium plating SOC is recorded as the second critical lithium plating SOC. The heating state is maintained, the lithium-ion battery continues to be used, and the current cycle number of the lithium-ion battery is recorded.

[0168] If the SOC of lithium plating is less than or equal to the second SOC threshold, the lithium-ion battery will immediately stop working, and the user will be prompted to replace the lithium-ion battery. The first SOC threshold is 30%, and the second SOC threshold is 25%.

[0169] Example 2

[0170] The detection of lithium plating SOC is the same as in Example 1.

[0171] <Lithium-ion battery protection operation>

[0172] If the lithium plating SOC is greater than the first SOC threshold, the measured lithium plating SOC is recorded as the first critical lithium plating SOC. The cooling device is started. When the temperature of the lithium-ion battery surface reaches below 25°C, the lithium-ion battery can be used normally, and the current cycle number of the lithium-ion battery is recorded.

[0173] If the second SOC threshold < lithium plating SOC ≤ the first SOC threshold, the measured lithium plating SOC is recorded as the second critical lithium plating SOC. The heating state is maintained, the lithium-ion battery continues to be used, and the current cycle number of the lithium-ion battery is recorded.

[0174] If the SOC of lithium plating is less than or equal to the third SOC threshold, the lithium-ion battery will immediately stop working and the user will be prompted to replace the lithium-ion battery.

[0175] If the third SOC threshold < lithium plating SOC ≤ second SOC threshold, maintain the first temperature, reduce the current charging voltage by 0.025V, and during the next lithium plating detection, reduce both the second and third SOC thresholds by 2.5% respectively. Again, determine the relationship between the lithium plating SOC and the second and third SOC thresholds, and so on. When the difference between the current charging voltage and the initial charging voltage of the lithium-ion battery exceeds the voltage difference threshold, record the measured lithium plating SOC as the final lithium plating SOC, immediately stop the lithium-ion battery from operating, prompt the user to replace the lithium-ion battery, and record the current cycle count of the lithium-ion battery. The third SOC threshold is 10%, and the voltage difference threshold is 0.1V.

[0176] Example 3

[0177] The detection of lithium plating SOC is the same as in Example 1.

[0178] <Lithium-ion battery protection operation>

[0179] If the lithium plating SOC is greater than the first SOC threshold, the measured lithium plating SOC is recorded as the first critical lithium plating SOC. The cooling device is started. When the temperature of the lithium-ion battery surface reaches below 25°C, the lithium-ion battery can be used normally, and the current cycle number of the lithium-ion battery is recorded.

[0180] If the second SOC threshold < lithium plating SOC ≤ the first SOC threshold, the measured lithium plating SOC is recorded as the second critical lithium plating SOC. The heating state is maintained, the lithium-ion battery continues to be used, and the current cycle number of the lithium-ion battery is recorded.

[0181] If the SOC of lithium plating is less than or equal to the third SOC threshold, the lithium-ion battery will immediately stop working and the user will be prompted to replace the lithium-ion battery.

[0182] If the third SOC threshold < lithium plating SOC ≤ second SOC threshold, maintain the first temperature, reduce the current charging voltage by 0.5A, and during the next lithium plating detection, again determine the relationship between the lithium plating SOC and the second and third SOC thresholds, and so on. When the difference between the current charging current and the initial charging current of the lithium-ion battery is greater than the current difference threshold, record the measured lithium plating SOC as the final lithium plating SOC, immediately stop the lithium-ion battery from working, prompt the user to replace the lithium-ion battery, and record the current cycle number of the lithium-ion battery. The current difference threshold is calculated as: second coefficient × battery rated capacity. In this embodiment, the second coefficient is 0.25, and the rated capacity of the lithium-ion battery is 5Ah, so the current difference threshold is 0.25 × 5 = 1.25.

[0183] Comparative Example 1

[0184] <Detection of Lithium Plating SOC>

[0185] The lithium-ion battery prepared in Preparation Example 1 was subjected to charge-discharge cycle operation at room temperature (25°C): it was charged with a constant current of 5A to 4.4V, charged with a constant voltage until the current dropped to 250mA, left to stand for 15min, and then discharged with a constant current of 5A to 2.8V, left to stand for 15min. The above charge-discharge cycle operation was repeated, and lithium plating was detected during each charge.

[0186] <Lithium-ion battery protection operation>

[0187] If the lithium plating SOC is greater than the first SOC threshold, the measured lithium plating SOC is recorded as the first critical lithium plating SOC. The lithium-ion battery continues to undergo charge-discharge cycles, and lithium plating is detected during each charge until the lithium plating SOC is less than or equal to the first SOC threshold. At this point, the battery stops charging and discharging, and the current cycle number of the lithium-ion battery is recorded. The first SOC threshold is 40%.

[0188] If the lithium plating SOC is less than or equal to the first SOC threshold, the lithium-ion battery will stop charging and discharging cycle operations.

[0189] Comparative Example 2

[0190] Except for the <Lithium-ion Battery Protection Operation>, which differs from Comparative Example 1, everything else is the same as Comparative Example 1.

[0191] If the lithium plating SOC is greater than the first SOC threshold, the measured lithium plating SOC is recorded as the first critical lithium plating SOC. The lithium-ion battery continues to perform charge-discharge cycle operations, and lithium plating is detected during each charge until the second SOC threshold is less than the lithium plating SOC and less than the first SOC threshold. The current cycle number of the lithium-ion battery is then recorded.

[0192] If the lithium plating SOC is less than or equal to the second SOC threshold, the lithium-ion battery will stop charging and discharging cycles; where the first SOC threshold is 30%.

[0193] If the second SOC threshold < lithium plating SOC ≤ first SOC threshold, the current charging voltage is reduced by 0.025V. In the next lithium plating detection, the first SOC threshold and the second SOC threshold are reduced by 2.5% respectively. The relationship between the lithium plating SOC and the first SOC threshold and the second SOC threshold is continued to be judged. This process is repeated until the lithium plating SOC ≤ second SOC threshold. The measured lithium plating SOC is recorded as the final lithium plating SOC. The lithium-ion battery stops charging and discharging cycle operation and the current cycle number of the lithium-ion battery is recorded.

[0194] Comparative Example 3

[0195] Except for the <Lithium-ion Battery Protection Operation>, which differs from Comparative Example 1, everything else is the same as Comparative Example 1.

[0196] If the lithium plating SOC is greater than the first SOC threshold, the measured lithium plating SOC is recorded as the first critical lithium plating SOC. The lithium-ion battery continues to perform charge-discharge cycle operations, and lithium plating is detected during each charge until the second SOC threshold is less than the lithium plating SOC and less than the first SOC threshold. The current cycle number of the lithium-ion battery is then recorded.

[0197] If the lithium plating SOC is less than or equal to the second SOC threshold, the lithium-ion battery will stop charging and discharging cycle operations.

[0198] If the second SOC threshold < lithium plating SOC ≤ first SOC threshold, the current charging current is reduced by 0.5A. During the next lithium plating detection, the relationship between the lithium plating SOC and the first and second SOC thresholds is determined again. This process continues until the lithium plating SOC ≤ second SOC threshold. The measured lithium plating SOC is recorded as the final lithium plating SOC, and the lithium-ion battery stops charging and discharging cycles. The current cycle number of the lithium-ion battery is recorded.

[0199] The performance data for Example 1 and Comparative Example 1 are shown in Table 1:

[0200] Table 1

[0201] Example 1 29.8％ 580 21.3％ 903 Comparative Example 1 29.9％ 622 \ \

[0202] In Table 1, “\” indicates that the result was not measured.

[0203] As can be seen from Example 1 and Comparative Example 1, when the same lithium plating SOC was detected, Example 1 detected it 42 cycles earlier, improving detection sensitivity and reducing the risk of lithium-ion battery failure. Example 1, through the auxiliary heating of a heating element, extended the charge-discharge cycle life of the lithium-ion battery by approximately 300 cycles compared to Comparative Example 1, thus extending the battery's lifespan and improving user experience.

[0204] The performance data for Example 2 and Comparative Example 2 are shown in Table 2:

[0205] Table 2

[0206]

[0207] In Table 2, “\” indicates that the result was not measured.

[0208] As can be seen from Example 2 and Comparative Example 2, when the same lithium plating SOC was detected, Example 2 detected it 42 cycles earlier, improving detection sensitivity and reducing the risk of lithium-ion battery failure. Example 2, through auxiliary heating with a heating element, extended the number of charge-discharge cycles of the lithium-ion battery in the normal voltage region by approximately 300 cycles and the final number of charge-discharge cycles by approximately 500 cycles, significantly extending the lifespan of the lithium-ion battery and improving user experience.

[0209] The performance data for Example 3 and Comparative Example 3 are shown in Table 3:

[0210] Table 3

[0211]

[0212]

[0213] In Table 3, “\” indicates that the result was not measured.

[0214] As can be seen from Example 3 and Comparative Example 3, when the same lithium plating SOC was detected, Example 3 detected it 42 cycles earlier, improving detection sensitivity and reducing the risk of lithium-ion battery failure. Example 3, through auxiliary heating with a heating element, extended the number of charge-discharge cycles of the lithium-ion battery in the normal voltage region by approximately 300 cycles and the final number of charge-discharge cycles by approximately 600 cycles, significantly extending the lifespan of the lithium-ion battery and improving user experience.

[0215] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0216] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0217] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for managing an electrochemical device, characterized in that, The method includes: In response to the temperature of the electrochemical device reaching a first temperature, an intermittent charging operation is performed on the electrochemical device, during which data related to the electrochemical device is acquired, and the lithium plating state-of-the-art (SOC) of the electrochemical device is determined based on the data related to the electrochemical device. In response to the lithium plating SOC being less than or equal to a first SOC threshold, the electrochemical device is subjected to a first charge-discharge cycle at the first temperature; or In response to the lithium plating state of charge (SOC) exceeding the first SOC threshold, the temperature of the electrochemical device is controlled to decrease to a second temperature, and a second charge-discharge cycle is performed on the electrochemical device at the second temperature, wherein the second temperature is lower than the first temperature. The data related to the electrochemical device includes the state of charge (SOC) and internal resistance of the electrochemical device. The intermittent charging operation includes multiple charging periods and multiple interruptions. The step of acquiring the data related to the electrochemical device during the intermittent charging operation and determining the lithium plating SOC of the electrochemical device based on the data related to the electrochemical device includes: During the intermittent charging operation, for each of the plurality of intermittent periods, the SOC and internal resistance of the electrochemical device during the intermittent period are obtained. Based on the plurality of SOCs of the electrochemical device and the plurality of internal resistances of the electrochemical device corresponding to the plurality of SOCs, a first curve is obtained. The first curve is a mapping curve corresponding to the SOC and internal resistance of the electrochemical device. Based on the first curve, the state of lithium deposition (SOC) of the electrochemical device is determined.

2. The electrochemical device management method according to claim 1, characterized in that, The step of performing a first charge-discharge cycle on the electrochemical device at the first temperature in response to the lithium plating SOC being less than or equal to a first SOC threshold includes: In response to the lithium plating SOC being less than or equal to the first SOC threshold and the lithium plating SOC being greater than the second SOC threshold, the electrochemical device is subjected to the first charge-discharge cycle at the first temperature.

3. The electrochemical device management method according to claim 2, characterized in that, The method further includes: In response to the lithium plating SOC being less than or equal to the second SOC threshold, the electrochemical device is controlled to stop operating, wherein the second SOC threshold is less than the first SOC threshold; Generate a prompt message.

4. The electrochemical device management method according to claim 2, characterized in that, The method further includes: In response to the lithium plating SOC being less than or equal to the second SOC threshold and the lithium plating SOC being greater than the third SOC threshold, at least one of the charging voltage or charging current of the electrochemical device is reduced.

5. The electrochemical device management method according to claim 4, characterized in that, The step of reducing at least one of the charging voltage or charging current of the electrochemical device includes: i-1 At the first temperature, the current charging voltage of the electrochemical device is reduced to a first charging voltage by a first reduction rate, wherein the first charging voltage is the updated current charging voltage; And / or, i-2 reduces the current charging current of the electrochemical device to a first charging current at the first temperature by a second reduction, the first charging current being the updated current charging current.

6. The electrochemical device management method according to claim 5, characterized in that, The method further includes: ii-1 Reduce the second SOC threshold and the third SOC threshold by the third reduction rate respectively to obtain the updated second SOC threshold and the updated third SOC threshold; iii-1 In response to the electrochemical device completing a third charge-discharge cycle at the first temperature, the electrochemical device is subjected to intermittent charging operation again. During the intermittent charging operation, data related to the electrochemical device is acquired. Based on the data related to the electrochemical device, the lithium plating SOC of the electrochemical device is determined, and the relationship between the lithium plating SOC and the updated second SOC threshold and the updated third SOC threshold is determined. iv-1 When the lithium plating SOC is greater than the updated third SOC threshold and less than the updated second SOC threshold, repeat steps i-1 to iii-1 until the difference between the current charging voltage and the initial charging voltage of the electrochemical device is greater than the voltage difference threshold, and generate a prompt message. Steps i-1 to iii-1 include: step i-1, step ii-1, and step iii-1.

7. The electrochemical device management method according to claim 5, characterized in that, The method further includes: ii-2 In response to the electrochemical device completing a third charge-discharge cycle at the first temperature, the electrochemical device is subjected to intermittent charging operation again. During the intermittent charging operation, data related to the electrochemical device is acquired. Based on the data related to the electrochemical device, the lithium plating SOC of the electrochemical device is determined, and the relationship between the lithium plating SOC and the second SOC threshold and the third SOC threshold is determined. iii-2 When the lithium plating SOC is greater than the third SOC threshold and less than the second SOC threshold, repeat steps i-2 to ii-2 until the difference between the current charging current and the initial charging current of the electrochemical device is greater than the current difference threshold, and generate a prompt message to prompt the user to replace the electrochemical device. Steps i-2 to ii-2 include: step i-2 and step ii-2.

8. The electrochemical device management method according to claim 1, characterized in that, The step of determining the lithium plating state of the electrochemical device based on the first curve includes at least one of method 1 or method 2, wherein: Method 1 includes: Taking the first derivative of the first curve yields the second curve; and The SOC corresponding to the first point on the second curve with a negative slope is determined as the SOC for lithium plating. Method 2 includes: The second curve is obtained by taking the first derivative of the first curve; Taking the second derivative of the second curve yields the third curve; and The SOC corresponding to the point where the ordinate of the third curve first appears to be less than zero is determined as the lithium plating SOC.

9. The electrochemical device management method according to claim 1, characterized in that, The intermittent charging operation includes multiple charging cycles, each charging cycle including a charging period and an intermittent period, during which the SOC of the electrochemical device increases by a unit magnitude.

10. The electrochemical device management method according to claim 9, characterized in that, The electrochemical device includes at least one of a lithium iron phosphate system electrochemical device, a nickel-cobalt-manganese oxide system electrochemical device, or a lithium cobalt oxide system electrochemical device, wherein... The electrochemical device is a lithium iron phosphate system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 15 seconds; The electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds; The electrochemical device is a lithium cobalt oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds.

11. The electrochemical device management method according to claim 10, characterized in that, The method satisfies any one of conditions a) to c): a) The electrochemical device is a lithium iron phosphate system electrochemical device, the electrochemical device is operated at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds; b) The electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the electrochemical device is at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds. c) The electrochemical device is a lithium cobalt oxide system electrochemical device, the electrochemical device is at a temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds.

12. The electrochemical device management method according to claim 1, characterized in that, Before performing intermittent charging operation on the electrochemical device in response to the temperature of the electrochemical device reaching a first temperature, the method further includes: The electrochemical device is heated to a first temperature, which is between 30°C and 55°C.

13. A charging device, characterized in that, The method includes a processor and a machine-readable storage medium storing machine-executable instructions that can be executed by the processor, wherein when the processor executes the machine-executable instructions, it implements the method according to any one of claims 1-12.

14. An electrochemical device, characterized in that, include: At least one heating element, a management unit, and a cooling device. The heating element is used to heat the electrochemical device to a first temperature; The management unit is used to perform intermittent charging operation on the electrochemical device when the temperature of the electrochemical device reaches a first temperature, acquire data related to the electrochemical device during the intermittent charging operation, and determine the lithium plating state occupancy (SOC) of the electrochemical device based on the data related to the electrochemical device. And, in response to the lithium plating SOC being less than or equal to a first SOC threshold, the electrochemical device is subjected to a first charge-discharge cycle at the first temperature; or In response to the lithium plating SOC being greater than the first SOC threshold, the cooling device is controlled to lower the temperature of the electrochemical device to a second temperature, and a second charge-discharge cycle is performed on the electrochemical device at the second temperature, wherein the second temperature is lower than the first temperature; The data related to the electrochemical device includes the state of charge (SOC) and internal resistance of the electrochemical device. The intermittent charging operation includes multiple charging periods and multiple interruptions. The management unit is specifically used for: During the intermittent charging operation, for each of the plurality of intermittent periods, the SOC and internal resistance of the electrochemical device during the intermittent period are obtained. Based on the plurality of SOCs of the electrochemical device and the plurality of internal resistances of the electrochemical device corresponding to the plurality of SOCs, a first curve is obtained. The first curve is a mapping curve corresponding to the SOC and internal resistance of the electrochemical device. Based on the first curve, the state of lithium deposition (SOC) of the electrochemical device is determined.

15. The electrochemical device according to claim 14, characterized in that, The management unit is specifically used for: In response to the lithium plating SOC being less than or equal to the first SOC threshold and the lithium plating SOC being greater than the second SOC threshold, the electrochemical device is subjected to a first charge-discharge cycle at the first temperature, the first temperature range being 30°C to 55°C.

16. The electrochemical device according to claim 15, characterized in that, The management unit is also used for: In response to the lithium plating SOC of the electrochemical device being less than or equal to the second SOC threshold, the electrochemical device is controlled to stop operating, wherein the second SOC threshold is less than the first SOC threshold; Generate a prompt message.

17. The electrochemical device according to claim 15, characterized in that, The management unit is also used for: In response to the lithium plating SOC being less than or equal to a second SOC threshold and the lithium plating SOC being greater than a third SOC threshold, at least one of the charging voltage or charging current of the electrochemical device is reduced.

18. The electrochemical device according to claim 14, characterized in that, The management unit is specifically used for: Taking the first derivative of the first curve yields the second curve; and The SOC corresponding to the first point on the second curve with a negative slope is determined as the lithium plating SOC; or The second curve is obtained by taking the first derivative of the first curve; Taking the second derivative of the second curve yields the third curve; and The SOC corresponding to the point where the ordinate of the third curve first appears to be less than zero is determined as the lithium plating SOC.

19. The electrochemical device according to claim 14, characterized in that, The intermittent charging operation includes multiple charging cycles, each charging cycle including a charging period and an intermittent period, during which the SOC of the electrochemical device increases by a unit magnitude.

20. The electrochemical device according to claim 19, characterized in that, The electrochemical device includes at least one of a lithium iron phosphate system electrochemical device, a nickel-cobalt-manganese oxide system electrochemical device, or a lithium cobalt oxide system electrochemical device, wherein the management unit is specifically used for: The electrochemical device is a lithium iron phosphate system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 15 seconds; The electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds; The electrochemical device is a lithium cobalt oxide system electrochemical device, the unit amplitude ranges from 0.5% to 10%, and the duration of the intermittent period ranges from 1 second to 30 seconds.

21. The electrochemical device according to claim 20, characterized in that, The management unit is specifically used for at least one of the following a) to c): a) The electrochemical device is a lithium iron phosphate system electrochemical device, the electrochemical device is in an ambient temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds; b) The electrochemical device is a lithium nickel cobalt manganese oxide system electrochemical device, the electrochemical device is in an ambient temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds; c) The electrochemical device is a lithium cobalt oxide system electrochemical device, the electrochemical device is in an ambient temperature of 30°C to 55°C, the unit amplitude ranges from 0.5% to 3%, and the duration of the intermittent period ranges from 1 second to 10 seconds.

22. The electrochemical device according to claim 14, characterized in that, The heating element is made of at least one of nickel, nickel-aluminum alloy, copper, polyimide, silicone, or a positive temperature coefficient material.

23. An electrical appliance, characterized in that, Includes the electrochemical device according to any one of claims 14-22.

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