Charging methods, electronic devices, processors, and readable storage media

Abstract

This application discloses a charging method, electronic device, processor, and readable storage medium. The charging method includes: stopping charging the battery cell in response to the battery cell's cycle count reaching a preset threshold, and stopping charging the battery cell in response to at least one of features (a), (b), (c), or (d). Wherein, (a) the battery cell's charging voltage reaches a rated voltage, (b) the battery cell's charging voltage reaches the rated voltage and remains there for a preset duration, (c) the battery cell's charging current is less than the current of the battery cell in the CC stage, and (d) the battery cell is charged to a preset capacity. In response to having a value of F(t) less than zero during the first duration, the charging current of the battery cell is reduced. F(t) is the second-order differential function of the battery cell's voltage function V(t). This application is capable of detecting lithium plating.

Description

Technical Field

[0001] This application relates to the field of battery charging and discharging technology, and more specifically to a charging method, electronic device, processor, and readable storage medium. Background Technology

[0002] As the number of cycles (also known as the number of charging cycles) increases, the probability of lithium plating at the anode of the battery cell increases. If the charging current remains constant during charging, lithium plating at the anode is likely to occur, causing the battery cell capacity to decay and increasing the safety risks such as fire. Summary of the Invention

[0003] This application provides a charging method, electronic device, processor, and readable storage medium to improve problems such as lithium plating in battery cells and the resulting capacity decay and fire.

[0004] In a first aspect, this application provides a charging method, comprising the following steps: stopping charging the battery cell in response to the battery cell's cycle number reaching a preset threshold and in response to at least one of features (a)-(d); and reducing the battery cell's charging current in response to a value of F(t) less than zero within a first duration, wherein the battery cell stops charging and supplying power to the load within the first duration. Wherein, (a) the battery cell's charging voltage reaches the rated voltage; (b) the battery cell's charging voltage reaches the rated voltage and remains there for a preset duration; (c) the battery cell's charging current is less than the current of the battery cell during the constant current charging phase; and (d) the battery cell is charged to a preset capacity C1. The F(t) is obtained by: (i) collecting the battery cell's voltage at second-duration intervals within the first duration to obtain a voltage function V(t); and (ii) performing a second-order differential operation on the voltage function V(t) to obtain F(t).

[0005] The beneficial effects of this application's technical solution are as follows: As the number of battery cell cycles increases, by performing a second-order differential operation on the sampled voltage and duration, it is detected whether the current charging current is within the lithium plating window. That is, it detects whether lithium plating occurs when charging with the current charging current. If so, the charging current is reduced to improve lithium plating, thereby mitigating battery capacity decay and reducing safety risks such as fire. Using this application's technical solution, lithium plating detection can be achieved through a voltage function, enabling non-destructive lithium plating detection.

[0006] In addition, the step of stopping charging the cell in response to the cell's cycle count reaching a preset threshold and in response to at least one of features (a)-(d) is to stop charging and sample the cell during the CC phase (constant current charging phase). During the CC phase, if the current charging current is greater than the lithium plating window, the cell will continue to plating lithium, and the amount of lithium plating will gradually increase. The voltage change corresponding to lithium plating is more obvious, which helps to improve the accuracy of lithium plating detection.

[0007] In one embodiment of this application, the actual capacity of the battery cell is C0, and the preset capacity C1 satisfies: C1=x*C0, and 50%≤x≤90%.

[0008] The beneficial effects of the technical solution in this application are: charging the battery cell to the capacity of this threshold helps to reflect the difference in voltage changes when lithium is deposited and when it is not, improves the accuracy of detecting whether lithium is deposited, and further helps to improve the lithium deposited phenomenon through charging control.

[0009] In one embodiment of this application, the preset duration is t0, and t0 satisfies: 0min≤t0≤3min.

[0010] In one embodiment of this application, the first duration is t1, and t1 satisfies: 0.01h≤t1≤2h.

[0011] In one embodiment of this application, the second duration is t2, which satisfies: 0.01ms≤t2≤2s.

[0012] The beneficial effects of the technical solution in this application are: if the preset time is too long, the lithium crystals that have been deposited will be re-intercalated, affecting the detection results of lithium deposition.

[0013] In one embodiment of this application, after the step of reducing the charging current of the battery cell in response to a value of F(t) less than zero within a first time period, the charging method further includes comparing the reduced charging current with a preset current, and stopping charging the battery cell and supplying power to the load in response to the reduced charging current being less than the preset current.

[0014] The beneficial effects of this technical solution are as follows: In response to the reduced charging current being less than a preset current, charging of the battery cell and power supply to the load are stopped. This helps to mitigate the damage to the battery cell caused by insufficient charging power.

[0015] Secondly, another embodiment of this application also provides an electronic device including a processor for performing steps in any of the aforementioned charging methods.

[0016] Thirdly, another embodiment of this application also provides a processor, including: a recording module and a charging control module. The recording module is used to record the number of cycles of the battery cell and determine whether a preset threshold has been reached. The charging control module is used to stop charging the battery cell in response to the recording module determining that the number of cycles of the battery cell has reached the preset threshold, and in response to at least one of features (a)-(d). Wherein, (a) the charging voltage of the battery cell reaches the rated voltage; (b) the charging voltage of the battery cell reaches the rated voltage and continues for a preset time; (c) the charging current of the battery cell is less than the current of the battery cell in the constant current charging stage; (d) the battery cell is charged to a preset capacity C1.

[0017] The charging control module is also used to respond to a value of F(t) that is less than zero during the first time period, reduce the charging current of the battery cell, stop charging the battery cell during the first time period, and supply power to the load. F(t) is obtained by the following methods: (i) during the first time period, the voltage of the battery cell is collected at intervals of the second time period to obtain the voltage function V(t), and (ii) the second-order differential operation is performed on the voltage function V(t) to obtain F(t).

[0018] In one embodiment of this application, the charging control module controls the charging of the battery cell to a preset capacity C1, and the actual capacity of the battery cell is C0, satisfying: C1=x*C0, and 50%≤x≤90%.

[0019] In one embodiment of this application, the charging control module is further configured to stop charging the battery cell and supplying power to the load in response to the reduced charging current being less than a preset current.

[0020] Fourthly, another embodiment of this application also provides a readable storage medium storing a computer program for being executed by a processor to perform the steps in any of the charging methods described above.

[0021] In the charging method, electronic device, processor, and readable storage medium of this application embodiment, as the number of battery cell cycles increases, by performing a second-order differential operation on the sampled voltage and duration, it is detected whether the current charging current is within the lithium plating window. If so, the charging current of the battery cell is reduced to improve the lithium plating phenomenon, thereby helping to improve battery cell capacity decay and reduce safety risks such as fire. Furthermore, this application stops charging and samples the voltage and duration during the CC stage (constant current charging stage). During the CC stage, if the current charging current is greater than the lithium plating window, the battery cell will continue to plating lithium, and the amount of accumulated lithium gradually increases. The voltage change corresponding to lithium plating is more distinct, which helps to improve the accuracy of lithium plating detection. Attached Figure Description

[0022] Figure 1 This is a schematic flowchart of a charging method according to an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the voltage function V(t) according to an embodiment of this application;

[0024] Figure 3 Yes Figure 2 The diagram shows the graph of the voltage function V(t) obtained by performing a first-order differential operation.

[0025] Figure 4 Yes Figure 2 The diagram shows the graph of the voltage function V(t) obtained by performing a second-order differential operation.

[0026] Figure 5 This is a schematic flowchart of a charging method according to another embodiment of this application;

[0027] Figure 6 This is a schematic block diagram of a processor according to an embodiment of this application. Detailed Implementation

[0028] This application proposes a charging method in which, when the number of cycles of a battery cell reaches a preset threshold, it is determined whether the current charging current is within the lithium plating window. If so, the current charging current is still used to charge the battery cell, and the number of cycles of the battery cell is continuously detected to perform the next lithium plating judgment. If not, it indicates that lithium plating has occurred in the battery cell, and the charging current is reduced (less than the current charging current) to improve the lithium plating phenomenon.

[0029] Battery cells include, but are not limited to, all types of primary batteries, secondary batteries, fuel cells, solar cells, and capacitors (e.g., supercapacitors). The battery cell may be a lithium secondary battery, including but not limited to lithium metal secondary batteries, lithium-ion secondary batteries, lithium polymer secondary batteries, and lithium-ion polymer secondary batteries. The battery cells in this application embodiment may exist in the form of a single battery cell, a battery unit, or a battery module.

[0030] The subject executing the charging method or the object embedded in the charging method of this application includes, but is not limited to: various charging devices; or the management system built into the aforementioned various battery cells, such as a battery management system (BMS); or power-consuming devices such as mobile phones and drones.

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly described below in conjunction with the embodiments and accompanying drawings. Obviously, what is described are only some embodiments of this application, and not all embodiments of this application. Based on the embodiments in this application, the following embodiments and their technical features can be combined with each other without conflict.

[0032] An embodiment of this application provides a charging method, including the following steps:

[0033] (1) Charging of the battery cell is stopped when the number of battery cycles reaches a preset threshold and when one of the following characteristics is met:

[0034] (a) The charging voltage of the battery cell reaches the rated voltage;

[0035] (b) The charging voltage of the battery cell reaches the rated voltage and continues for a preset duration;

[0036] (c) The charging current of the battery cell is less than the current of the battery cell in the CC stage;

[0037] (d) Charge the battery cells to the preset capacity.

[0038] (2) In response to a value of F(t) less than zero during the first time period, the charging current of the battery cell is reduced, and the battery cell stops charging and supplying power to the load during the first time period. The F(t) is obtained using the following method:

[0039] (i) Within the first time period, the voltage of the battery cell is collected at second time intervals to obtain the voltage function V(t); and

[0040] (ii) Perform a second-order differential operation on the voltage function V(t) to obtain F(t).

[0041] As the number of battery cell cycles increases, by performing second-order differential operations on the sampled voltage and duration, and based on the value of F(t), it is determined whether the current charging current is within the lithium plating window. If so, the current charging current is reduced to improve the lithium plating phenomenon, which is beneficial for improving the battery cell capacity decay and reducing safety risks such as fire.

[0042] The above (a), (b), (c), and (d) describe the characteristics of the battery cell during the CC stage. For example, towards the end of the CC stage, the charging voltage of the battery cell gradually increases and reaches the rated voltage, while the charging current reaches its peak. Based on at least one of the characteristics (a), (b), (c), and (d), charging of the battery cell is stopped, thus ceasing voltage and duration sampling during the CC stage. During the CC stage, if the current charging current exceeds the lithium plating window, the battery cell will continue to plating lithium, with the accumulated lithium gradually increasing. The voltage change corresponding to lithium plating is more distinct, which helps improve the accuracy of lithium plating detection.

[0043] The embodiments of this application do not sample voltage and duration during the CV stage (constant voltage charging stage) because: during the CV stage, the charging current of the cell gradually decreases, and the lithium plating of the cell will slowly embed into the electrode sheet of materials such as graphite, making it difficult to improve the accuracy of lithium plating detection.

[0044] It should be understood that the preset duration in feature (b) can be adaptively set according to factors such as the cell model. For example, in one embodiment, the preset duration is t0, satisfying: 0min≤t0≤3min. Furthermore, feature (c) can be understood as: 1. The charging current of the cell is less than the current of the cell in the CC stage; 2. The charging current of the cell is less than a preset percentage of the current of the cell in the CC stage, that is, the charging current of the cell is I1, and the current in the CC stage is I0, satisfying: I1=k*I0, and 95%≤k<100%.

[0045] The process and principle of each step in this embodiment will be described in detail below. For example, the description of step (i) can be found in the description of step S2 below; the description of step (ii) can be found in the description of step S3 below.

[0046] Please see Figure 1 As shown, the charging method may include the following steps S1 to S4.

[0047] S1. In response to the cell's cycle count reaching a preset threshold, the cell is charged to a preset capacity, wherein charging of the cell is stopped in response to one of features (a), (b), (c), and (d); wherein (a) the cell's charging voltage reaches the rated voltage; (b) the cell's charging voltage reaches the rated voltage and continues for a preset duration; (c) the cell's charging current is less than the cell's current in the CC stage; and (d) the cell is charged to the preset capacity.

[0048] The cycle count of a battery cell can be understood as follows: when the battery cell's usage reaches 100% of its capacity, it is counted as one cycle. When the count reaches n (n is a positive integer), the cycle count is determined to be n. It should be understood that the value of n can be adapted to the application scenario. In some embodiments, the value of n includes, but is not limited to, 100 ≤ n ≤ 1000; alternatively, 200 ≤ n ≤ 800 or 500 ≤ n ≤ 600. For example, if the battery cell's warranty commitment states that no safety issues will occur if the cell's cycle count is within 300, then the value of n can be 300.

[0049] In some embodiments, the preset capacity can be lower than the actual capacity of the battery cell. For example, the preset capacity is C1, and the actual capacity of the battery cell is C0, satisfying: C1 = x * C0, and 50% ≤ x ≤ 90%. When the battery cell is charged to this threshold capacity (electrical capacity), the difference in voltage change over time is significant for both lithium plating and non-lithium plating phenomena, which can improve the accuracy of lithium plating detection and further facilitate the improvement of lithium plating phenomena through charging control. For example, when x = 100%, C1 = C0, the battery cell is fully charged, the battery cell voltage drops rapidly, and the difference in voltage change corresponding to lithium plating and non-lithium plating is small, making it difficult to accurately determine whether lithium plating has occurred.

[0050] Taking a lithium-ion battery as an example, the actual capacity C0 is obtained as follows: At 25°C, the lithium-ion battery is charged at a constant current of 0.2C until the cell voltage reaches 4.45V. Then, it is charged at a constant voltage of 4.45V until the current reaches 0.025C. Next, it is discharged at a constant current of 0.2C until the cell voltage reaches 3.0V. The actual capacity of the battery at this point is recorded. This process is repeated three times, and the average of the three recorded actual capacities is calculated as the actual capacity C0 of the cell. It should be understood that this application can adopt an appropriate method to obtain the actual capacity C0 of the cell according to the type of cell. Different types of cells may require different parameters when obtaining the actual capacity C0.

[0051] S2. Stop charging the battery cell and supplying power to the load during the first time period, and collect the voltage of the battery cell at the second time interval to obtain the voltage function V(t).

[0052] Although the battery cell does not supply power to the load, a stationary battery cell will still discharge slowly, such as... Figure 2 As shown, the voltage (V) of the battery cell gradually decreases as time (t) changes.

[0053] The first duration is greater than the second duration, and the specific values ​​of both can be determined according to actual needs. In some embodiments, the first duration is t1 and the second duration is t2, satisfying: 0.01h≤t1≤2h, 0.01ms≤t2≤2s.

[0054] The first duration is the sampling duration, and the second duration is the sampling time interval. A longer sampling duration and a shorter sampling time interval improve the accuracy of lithium plating detection. However, excessively long sampling durations or short sampling intervals are detrimental to reflecting the true extent of lithium plating. For example, if the sampling duration is too long, the cell voltage changes less in the latter half of the sampling period; if the sampling time interval is too short, the difference in voltage changes is also small, both affecting the accuracy of lithium plating detection. By using the aforementioned threshold settings, the embodiments of this application enable a clear distinction in cell voltage changes within the sampling period, which is beneficial for improving the accuracy of lithium plating detection.

[0055] S3. Perform a second-order differential operation on the voltage function V(t) to obtain F(t).

[0056] S4. In response to a value of F(t) that is less than zero within the first time period, the charging current of the battery cell is reduced.

[0057] If the current charging current is within the lithium plating window, the cell will exhibit voltage relaxation. The embodiments of this application can detect whether voltage relaxation occurs within the sampling period by performing a second-order differential operation on the voltage. If it does not occur, the value of F(t) will be greater than zero; if it does occur, F(t) will have a value less than zero. Based on this, it can be determined whether the current charging current is within the lithium plating window.

[0058] For example, when the cell reaches 300 cycles, the initial charging current is recorded as 7.5A. Lithium plating detection is performed on the 301st cycle. After the cell is charged to a preset capacity, it is placed in a resting state. For example, if the maximum discharge voltage of the cell at the preset capacity is 4.05V, the resting time is 2 hours. During the resting period, the cell stops charging and supplying power to the load. Voltage sampling is performed on the cell during the resting period at 10ms intervals. The sampled voltage conforms to the following... Figure 2 The curve relationship shown is in Figure 2 In the figure, the horizontal axis represents time (t) and the vertical axis represents voltage (V). This curve represents the relationship between voltage and time, and is denoted as the voltage function V(t).

[0059] Then, using a program embedded in the BMS, the voltage function V(t) is subjected to second-order differentiation, and first-order differentiation is performed using the following relation 1-1, to obtain the following... Figure 3 The curve relationship shown is in Figure 3 In the diagram, the horizontal axis represents the value obtained from the first-order differential operation, and the vertical axis represents time (t). Continuing with the second-order differential operation using the following relation 1-2, we obtain the following... Figure 4 The curve relationship shown is denoted as the second-order differential function F(t). In Figure 4 In the figure, the horizontal axis represents the value obtained from the second-order differential operation, and the vertical axis represents time (t).

[0060]

[0061]

[0062] The value of F(t) during the entire resting period is determined, for example, by combining... Figures 2 to 4 As shown, taking the charging of the battery cell to the preset capacity of 5C (coulombs), 0.3C and 0.2C as examples, curve L11 represents the voltage function V(t) when the battery cell capacity is 5C, curve L21 represents the voltage function V(t) when the battery cell capacity is 0.3C, and curve L31 represents the voltage function V(t) when the battery cell capacity is 0.2C.

[0063] exist Figure 3In the diagram, curve L12 represents the first-order differential function when the cell charge is 5C, curve L22 represents the first-order differential function when the cell charge is 0.3C, and curve L32 represents the first-order differential function when the cell charge is 0.2C. For example... Figure 3 As shown, the battery cell charged at 5C experiences rapid voltage increases and decreases over a period of time, exhibiting voltage relaxation. Figure 4 As shown, after performing the second-order differential operation, the voltage relaxation phenomenon is manifested by F(t) being less than 0, while when the voltage relaxation phenomenon does not occur, the value of F(t) is always greater than 0. Figure 4 In the diagram, curve L13 represents the first-order differential function when the battery cell charge is 5C, curve L23 represents the first-order differential function when the battery cell charge is 0.3C, and curve L33 represents the first-order differential function when the battery cell charge is 0.2C.

[0064] If F(t) is greater than 0 during the resting period, it indicates that no lithium plating has occurred, and the cell can continue to be charged at the initial current of 7.5A. The next lithium plating test will be performed after a certain number of cycles. If F(t) is less than 0 during the resting period, the charging current will be reduced, for example, by 0.2A, and the cells will be cycled at the new current of 7.3A. The next lithium plating test will be performed after a certain number of cycles.

[0065] As can be seen from the above, as the number of battery cell cycles increases, the current charging current is detected to be within the lithium plating window by performing a second-order differential operation on the sampled voltage and duration. If it is, the current charging current is reduced to improve the lithium plating phenomenon, which is beneficial to improve the battery cell capacity decay and reduce safety risks such as fire. If not, the current charging current can be maintained to execute the next cycle and perform the next lithium plating detection. The steps of the next lithium plating detection are the same as the principle and execution process of the aforementioned steps S1 to S4.

[0066] The magnitude of the reduction in charging current can be determined according to actual needs. The aforementioned 0.2A is merely an example. The magnitude of the reduction in charging current is the difference between the current charging current and the new charging current. In some embodiments, this magnitude is greater than 0.01 throughout the entire lifespan of a single cell, and this magnitude can be varied. Optionally, the magnitude can gradually increase as the cell cycle count increases. For example, the magnitude of the first reduction in charging current is 0.2A, and the magnitude of the fifth reduction in charging current is 0.5A.

[0067] It should be understood that as the cell cycle count increases, the preset threshold for triggering the next lithium plating detection can be changed regardless of whether the value of F(t) in the current lithium plating detection stage is greater than 0. For example, the preset threshold for triggering the current lithium plating detection can be denoted as the first cycle count threshold, and the preset threshold for triggering the next lithium plating detection can be denoted as the second cycle count threshold. If the value of F(t) is greater than 0 in the current lithium plating detection stage, it indicates that the cell safety is stable, and the second cycle count threshold can be set higher than the first cycle count threshold. Alternatively, considering that the cell will age as the cell cycle count increases, the second cycle count threshold can be set lower than the first cycle count threshold, which is equivalent to increasing the frequency of lithium plating detection, which is beneficial for timely detection of potential safety hazards. If F(t) is less than 0 in the current lithium plating detection stage, it indicates that the cell safety has decreased, and the second cycle count threshold is set lower than the first cycle count threshold.

[0068] Please see Figure 5 This is a schematic flowchart illustrating a charging method according to another embodiment of this application. Figure 1 Based on the described embodiments, the charging method further includes step S5.

[0069] S5: Compare the reduced charging current (threshold) with the preset current (threshold). That is, determine whether the reduced charging current is greater than the preset current. If not, proceed to step S6. If yes, proceed to steps S1 to S4.

[0070] S6: In response to the reduced charging current being less than the preset current, charging of the battery cell and discharging of the load are stopped, that is, the battery cell is no longer used.

[0071] If the reduced charging current is greater than the preset current, the next lithium plating detection is performed, which can be regarded as continuing to execute steps S1 to S4.

[0072] In some embodiments, the preset current can be the rated charging current or the minimum charging current of the battery cell, which can help mitigate the damage to the battery cell caused by insufficient charging power.

[0073] Embodiments of this application further provide a processor, such as Figure 6 As shown, the processor 60 includes: a recording module 61, a charging control module 62, a data acquisition module 63, and a calculation module 64.

[0074] The recording module 61 is used to record the number of cycles of the battery cell and determine whether a preset threshold has been reached.

[0075] If the recording module 61 determines that the number of battery cell cycles has reached a preset threshold, the charging control module 62 will then control the charging of the battery cell. Specifically, the charging control module 62 will stop charging the battery cell in response to one of the following characteristics:

[0076] (a) The charging voltage of the battery cell reaches the rated voltage;

[0077] (b) The charging voltage of the battery cell reaches the rated voltage and continues for a preset duration;

[0078] (c) The charging current of the battery cell is less than the current of the battery cell during the constant current charging stage.

[0079] (d) Charge the battery cells to the preset capacity.

[0080] The acquisition module 63 is used to acquire the voltage of the battery cell at a second time interval within a first time period. Within the first time period, the charging control module 62 controls the battery cell to stop charging and to supply power to the load.

[0081] The calculation module 64 is used to obtain the voltage function V(t) based on the collected voltage, and to perform a second-order differential operation on the voltage function V(t) to obtain F(t). If the calculation module 64 determines that there is a value of F(t) less than zero within the first time period, the charging control module 62 is also used to reduce the charging current of the battery cell.

[0082] The processor 60 executes the relevant steps of the charging method of any of the foregoing embodiments through embedded programs or software code. For example, the charging control module 62 controls the charging of the battery cell to a preset capacity C1, where the actual capacity of the battery cell is C0, satisfying: C1 = x * C0, and 50% ≤ x ≤ 90%. As another example, the calculation module 64 is further configured to compare the reduced charging current with a preset current, and, if it determines that the reduced charging current is less than the preset current, the charging control module 62 is configured to stop charging the battery cell and supply power to the load.

[0083] It should be understood that the above modules are only a division of logical functions, and in actual implementation, they can be various hardware units of the processor 60. Furthermore, the processor 60 can be a processor of an electronic device such as a mobile phone, for example, a CPU, or a chip of a charging device (such as a charger), such as a BMS chip.

[0084] For example, in other embodiments, the processor 60 may include a recording module 61 and a charging control module 62, but does not include a data acquisition module 63 and a calculation module 64.

[0085] The recording module 61 is used to record the number of cycles of the battery cell and determine whether a preset threshold has been reached.

[0086] The charging control module 62 is used to respond to the recording module 61 determining that the number of cycles of the battery cell has reached a preset threshold, controlling the charging of the battery cell to a preset capacity, and stopping the charging of the battery cell and the supply of power to the load within a first time period after the preset capacity has been reached. The charging control module 62 is also used to respond to a value of F(t) that is less than zero within the first time period, reducing the charging current of the battery cell. F(t) is obtained using the following method:

[0087] (i) Within the first time period, the voltage of the battery cell is collected at second time intervals to obtain the voltage function V(t); and

[0088] (ii) Perform a second-order differential operation on the voltage function V(t) to obtain F(t).

[0089] This application also provides an electronic device that includes the processor 60 of any of the foregoing embodiments, and thus can have the effects corresponding to the processor 60. This electronic device includes, but is not limited to: various charging devices such as chargers and charging piles; various battery cells; or electrical appliances.

[0090] Electrical devices can be considered as loads, and battery cells supply power to these loads. Electrical devices can be implemented in various specific forms, such as drones, electric cleaning tools, motors, energy storage products such as backup power supplies, electric vehicles, electric bicycles, electric navigation tools, and other electronic products.

[0091] This application also provides a readable storage medium storing a program that, when executed by a processor, implements the relevant steps of the charging method in any of the above embodiments.

[0092] The embodiments of the processor, electronic device, and readable storage medium provided in the embodiments of this application include all the technical features of the various embodiments of the above-described charging method. The extended and explanatory content of the specification is the same as that of the various embodiments of the above-described charging method, and will not be repeated here.

[0093] The above-described charging method can be implemented using software and necessary general-purpose hardware platforms, or it can be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a hardware device (such as a chip) to execute the method of each embodiment of this application.

[0094] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made using the content of this specification and drawings are similarly included in the patent protection scope of this application.

[0095] Although this document uses terms such as “first,” “second,” etc., to describe various types of information, this information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. The singular forms “a,” “an,” and “the” used herein are intended to also include the plural forms. The terms “or” and “and / or” are interpreted as inclusive, or meaning either one or any combination thereof. Exceptions to this definition occur only when combinations of elements, functions, steps, or operations are inherently mutually exclusive in some way.

Claims

1. A charging method, characterized in that, The charging method includes: Charging of the battery cell is stopped in response to the battery cell reaching a preset threshold number of cycles and in response to at least one of features (a)-(d): (a) The charging voltage of the battery cell reaches the rated voltage; (b) The charging voltage of the battery cell reaches the rated voltage and continues for a preset duration; (c) The charging current of the battery cell is less than the current of the battery cell during the constant current charging stage; (d) Charge the battery cell to a preset capacity C1; In response to the battery cell reaching a preset threshold number of cycles and having a value of F(t) less than zero within a first duration, the charging current of the battery cell is reduced. During the first duration, the battery cell stops charging and begins supplying power to the load. The F(t) is obtained using the following method: (i) Within the first time period, the voltage of the battery cell is collected at second time intervals to obtain the voltage function V(t); and (ii) Perform a second-order differential operation on the voltage function V(t) to obtain F(t).

2. The charging method according to claim 1, characterized in that, The actual capacity of the battery cell is C0, and the preset capacity C1 satisfies: C1 = x * C0, and 50% ≤ x ≤ 90%.

3. The charging method according to claim 1, characterized in that, The preset duration is t0, and t0 satisfies: 0 min ≤ t0 ≤ 3 min.

4. The charging method according to claim 1, characterized in that, The first duration is t1, and t1 satisfies: 0.01h≤t1≤2h.

5. The charging method according to claim 1 or 4, characterized in that, The second duration is t2, which satisfies: 0.01ms≤t2≤2s.

6. The charging method according to claim 1, characterized in that, After the step of reducing the charging current of the battery cell in response to a value of F(t) that is less than zero during the first time period, the charging method further includes: The reduced charging current is compared with the preset current; and In response to the reduced charging current being less than the preset current, charging of the battery cell is stopped and power supply to the load is started.

7. An electronic device comprising a processor, characterized in that, The processor is used to execute the charging method according to any one of claims 1 to 6.

8. A processor, characterized in that, include: The recording module is used to record the number of cycles of the battery cell and determine whether a preset threshold has been reached. A charging control module is configured to stop charging the battery cell in response to the recording module determining that the number of cycles of the battery cell has reached a preset threshold, and in response to at least one of features (a)-(d): (a) The charging voltage of the battery cell reaches the rated voltage; (b) The charging voltage of the battery cell reaches the rated voltage and continues for a preset duration; (c) The charging current of the battery cell is less than the current of the battery cell during the constant current charging stage; (d) Charge the battery cell to a preset capacity C1; The charging control module is also used to respond to the battery cell's cycle count reaching a preset threshold and to reduce the charging current of the battery cell when it has a value of F(t) less than zero within a first duration. During the first duration, the battery cell stops charging and begins supplying power to the load. The F(t) is obtained using the following method: (i) Within the first time period, the voltage of the battery cell is collected at second time intervals to obtain the voltage function V(t); and (ii) Perform a second-order differential operation on the voltage function V(t) to obtain F(t).

9. The processor according to claim 8, characterized in that, The actual capacity of the battery cell is C0, and the preset capacity C1 satisfies: C1 = x * C0, and 50% ≤ x ≤ 90%.

10. A readable storage medium storing a computer program, characterized in that, The computer program is used to be run by a processor to perform the charging method according to any one of claims 1 to 6.

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