Battery charging method, device, system, and medium

Abstract

This application provides a battery charging method, device, system, and medium. The battery charging method includes: acquiring the charging current corresponding to each constant current charging stage in a plurality of constant current charging stages of the battery; determining the charging duration corresponding to each constant current charging stage based on the charging current corresponding to the constant current charging stage and the rate of change of the solid electrolyte interfacial film thickness growth point of the battery, wherein the rate of change of ...

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery charging method, device, system and medium. Background Technology

[0002] Liquid batteries are widely used in electronic products, including smartphones, laptops, wearable devices, and electric vehicles, due to their high energy density and thinness.

[0003] Liquid batteries often require fast charging in practical applications, and high-rate charging can effectively shorten charging time. During high-rate charging, the battery control system first uses a high current to charge the battery at a constant current until a certain voltage is reached, then uses the battery's standard voltage to charge at a constant voltage until the standard voltage is reached. However, the high charging current at high rates has a significant impact on the solid electrolyte interface (SEI) film, which maintains the battery's charge-discharge cycle stability. High-rate charging causes significant changes in the SEI film, resulting in an excessively thick SEI film, which consumes too much electrolyte, leading to an excessively high rate of increase in internal resistance. This has a very negative impact on the battery's cycle performance and ultimately affects its lifespan.

[0004] Therefore, a battery charging solution is needed that can reduce the rate of increase in battery internal resistance, thereby improving battery life. Summary of the Invention

[0005] This application provides a battery charging method, device, system, and medium to solve the technical problem that existing charging processes increase battery internal resistance, thereby affecting battery lifespan.

[0006] In a first aspect, this application provides a battery charging method, comprising:

[0007] Obtain the charging current corresponding to each constant current charging stage in the multiple constant current charging stages of the battery;

[0008] For each constant current charging stage, the charging duration corresponding to the constant current charging stage is determined based on the charging current corresponding to the constant current charging stage and the rate of change of the solid electrolyte interface film thickness growth of the battery. The rate of change is obtained by monitoring the battery charging when the charging current corresponding to the constant current charging stage is controlled, and the rate of increase of the solid electrolyte interface film thickness corresponding to the rate of change exceeds a preset rate.

[0009] Based on the charging current and charging duration corresponding to each constant current charging stage, the battery is controlled to perform constant current charging until the charging termination condition is met, at which point the charging ends.

[0010] In one embodiment, determining the charging duration corresponding to the constant current charging stage based on the charging current corresponding to the constant current charging stage and the rate of change of the solid electrolyte interface film thickness of the battery includes:

[0011] Determine the correspondence between the charging duration and the rate of change of the solid electrolyte interface film thickness of the battery when the battery is charged at a constant current with the charging current corresponding to the constant current charging stage.

[0012] Based on the correspondence between the charging time and the rate of change of the solid electrolyte interface film thickness growth of the battery, the charging time when the solid electrolyte interface film thickness growth rate is less than the preset thickness growth rate is determined, which is the charging time corresponding to the constant current charging stage.

[0013] In one embodiment, the plurality of constant current charging stages include at least a first constant current charging stage, a second constant current charging stage, and a third constant current charging stage, wherein the first charging current corresponding to the first constant current charging stage is greater than the second charging current corresponding to the second constant current charging stage, and the second charging current is greater than the third charging current corresponding to the third constant current charging stage.

[0014] In one embodiment, controlling the battery to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage includes:

[0015] Based on the first charging current and the first charging duration corresponding to the first constant current charging stage, the battery is controlled to perform constant current charging.

[0016] Based on the second charging current and the second charging duration corresponding to the second constant current charging stage, the battery is controlled to perform constant current charging.

[0017] The battery is controlled to perform constant current charging based on the third charging current and the third charging duration corresponding to the third constant current charging stage.

[0018] In one embodiment, the first charging current ranges from 3C to 4C, the second charging current ranges from 1C to 1.5C, and the third charging current ranges from 0.5C to 0.7C.

[0019] In one embodiment, controlling the battery to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage, until the charging termination condition is met, and then ending the charging process includes:

[0020] Based on the charging current and charging duration corresponding to each constant current charging stage, the battery is controlled to perform constant current charging until the cutoff voltage is reached, at which point the battery is controlled to perform constant voltage charging.

[0021] During the constant voltage charging process of the battery, when the cutoff current is reached, the charging termination condition is met, and the charging ends.

[0022] On the other hand, this application provides a battery control system, including:

[0023] The acquisition module is used to acquire the charging current corresponding to each constant current charging stage in the multiple constant current charging stages of the battery.

[0024] The processing module is used to determine the charging duration corresponding to each constant current charging stage based on the charging current corresponding to the constant current charging stage and the rate of change of the solid electrolyte interface film thickness growth of the battery. The rate of change is obtained by monitoring the charging of the battery when the charging current corresponding to the constant current charging stage is controlled, and the rate of increase of the solid electrolyte interface film thickness corresponding to the rate of change exceeds a preset rate.

[0025] The control module is used to control the battery to perform constant current charging according to the charging current and charging duration corresponding to each constant current charging stage, until the charging termination condition is reached and the charging ends.

[0026] In one embodiment, the processing module is specifically used for:

[0027] Determine the correspondence between the charging duration and the rate of change of the solid electrolyte interface film thickness of the battery when the battery is charged at a constant current with the charging current corresponding to the constant current charging stage.

[0028] Based on the correspondence between the charging time and the rate of change of the solid electrolyte interface film thickness growth of the battery, the charging time when the solid electrolyte interface film thickness growth rate is less than the preset thickness growth rate is determined, which is the charging time corresponding to the constant current charging stage.

[0029] On the other hand, this application provides an electronic device, including a processor and a memory communicatively connected to the processor;

[0030] The memory stores computer-executed instructions;

[0031] The processor executes computer execution instructions stored in the memory to implement the method as described in the first aspect.

[0032] On the other hand, this application provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, are used to implement the method described in the first aspect.

[0033] On the other hand, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.

[0034] The battery charging method provided in the embodiments of this application includes: acquiring the charging current corresponding to each constant current charging stage in a plurality of constant current charging stages of the battery; for each constant current charging stage, determining the charging duration corresponding to the constant current charging stage based on the charging current corresponding to the constant current charging stage and the rate of change of the solid electrolyte interface film thickness growth of the battery, wherein the rate of change is monitored when the battery is charged by controlling the charging current corresponding to the constant current charging stage, and the rate of increase of the solid electrolyte interface film thickness corresponding to the rate of change exceeds a preset rate; controlling the battery to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage until the charging termination condition is reached, and ending the charging.

[0035] Understandably, as battery charging progresses, the SEI (Sediment Injection) of the battery noticeably thickens. Initially, the SEI thickens slowly, but this rate increases significantly with charging time. There is a point of inflection in the SEI thickening rate; before this point, the SEI thickness increases at a relatively low rate, while after this point, the rate of increase abruptly increases. That is, the SEI thickness increase rate at this point exceeds a preset rate. For any constant-current charging stage, using this point of inflection as a dividing point, the charging time before this point is set as the constant-current charging time for that stage. This effectively suppresses excessive SEI growth. Therefore, the method provided in this application can maintain a reasonable residual electrolyte level inside the battery, reducing the rate of increase in internal resistance, maintaining a low internal resistance value, and avoiding adverse effects on the battery's cycle performance, thereby improving battery lifespan. Furthermore, it can significantly shorten the battery charging time. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] Figure 1 A graph showing the relationship between charge, current, and SEI thickness as a function of charging time during the charging process of a battery in the prior art.

[0038] Figure 2 A schematic diagram illustrating the application scenario of the battery charging method provided in this application;

[0039] Figure 3 A schematic flowchart of a battery charging method provided in one embodiment of this application;

[0040] Figure 4 A graph showing the change in the thickness of the solid electrolyte interphase (SEI) film of a battery with charging time during constant current charging at a certain charging current, provided as an embodiment of this application;

[0041] Figure 5 A schematic diagram illustrating the change in charging current during battery charging in a battery charging method provided in an embodiment of this application;

[0042] Figure 6 A graph showing the relationship between the rate of change of battery internal resistance and the number of cycles for different battery charging methods.

[0043] Figure 7 A schematic diagram of a battery control system provided for one embodiment of this application;

[0044] Figure 8 A schematic diagram of an electronic device provided for one embodiment of this application.

[0045] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0046] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0047] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0048] First, let me explain the terms used in this application:

[0049] A solid electrolyte interface (SEI) is a passivation layer formed on the surface of a liquid lithium-ion battery during the initial charge and discharge process, where the electrode material and electrolyte react at the solid-liquid interface. Lithium ions can freely intercalate and deintercalate through this passivation layer, exhibiting characteristics of a solid electrolyte. However, this passivation layer effectively prevents the passage of solvent molecules, avoiding damage to the electrode material caused by solvent molecule co-intercalation. Therefore, the presence of a solid electrolyte interface significantly improves the battery's cycle performance and lifespan.

[0050] The battery charging method, device, system, and medium of this application can be used in applications involving liquid battery charging. The liquid battery can be a non-aqueous lithium-ion secondary battery, i.e., a non-aqueous lithium-ion battery that can be cyclically recharged.

[0051] In practical applications, liquid batteries often require fast charging, and high-rate charging can effectively shorten charging time. During high-rate charging, the battery control system first uses a high current to charge the battery at a constant current. After reaching a certain voltage, it then uses the battery's standard voltage to charge the battery at a constant voltage until it reaches the standard battery voltage.

[0052] However, when using high-rate charging, the higher charging current has a significant impact on the solid electrolyte interface (SEI) film that maintains the battery's charge-discharge cycle stability. High-rate charging causes significant changes in the SEI film, resulting in an excessively thick SEI film, which consumes too much electrolyte, leads to an excessively high rate of increase in battery internal resistance, and has a very adverse effect on the battery's cycle performance, thereby affecting battery life.

[0053] Figure 1 This graph illustrates the relationship between charge, current, and SEI thickness as a function of charging time for a battery in the prior art. Figure 1 As shown, the first charging stage CC is a constant current charging stage, charging with a relatively large current. The second charging stage CV is a constant voltage charging stage, continuing until charging is complete. Figure 1 As shown, when charging with a large current, the SEI thickness does not change significantly in the Ta stage as the charging time increases, but changes significantly after the Ta stage. This results in an excessively large SEI thickness after charging, which consumes too much electrolyte and leads to an excessively high rate of increase in battery internal resistance.

[0054] Based on this technical problem, the inventive concept of this application is: how to provide a battery charging method that can reduce the rate of increase of battery internal resistance, thereby improving battery life.

[0055] The battery charging method provided in this application aims to solve the above-mentioned technical problems of the prior art. The method includes: acquiring the charging current corresponding to each constant current charging stage in a plurality of constant current charging stages of the battery; for each constant current charging stage, determining the charging duration corresponding to that constant current charging stage based on the charging current corresponding to that constant current charging stage and the rate of change of the solid electrolyte interface film thickness growth point of the battery, wherein the rate of change of ...

[0056] Understandably, as battery charging progresses, the SEI (Sediment Injection) of the battery noticeably thickens. Initially, the SEI thickens slowly, but this rate increases significantly with charging time. There is a point of inflection in the SEI thickening rate; before this point, the SEI thickness increases at a relatively low rate, while after this point, the rate of increase abruptly increases. That is, the SEI thickness increase rate at this point exceeds a preset rate. For any constant-current charging stage, using this point of inflection as a dividing point, the charging time before this point is set as the constant-current charging time for that stage. This effectively suppresses excessive SEI growth. Therefore, the method provided in this application can maintain a reasonable residual electrolyte level inside the battery, reducing the rate of increase in internal resistance, maintaining a low internal resistance value, and avoiding adverse effects on the battery's cycle performance, thereby improving battery lifespan. Furthermore, it can significantly shorten the battery charging time.

[0057] The battery charging method provided in this application is applied to electronic devices, such as controllers installed in terminal devices, controllers for remotely controlling terminal devices, etc., and the terminal devices contain lithium-ion batteries. Figure 2 This is a schematic diagram illustrating the application of the battery charging method provided in this application. In the diagram, the electronic device acquires the charging current corresponding to each constant current charging stage in multiple constant current charging stages of the battery. Figure 2(Taking the example of obtaining the charging current corresponding to a constant current charging stage as an illustration), the battery is then charged using the charging current corresponding to that constant current charging stage, and the rate change points are monitored. Based on the charging current corresponding to that constant current charging stage and the rate change points of the solid electrolyte interface film thickness increase of the battery, the charging duration corresponding to that constant current charging stage is determined. After obtaining the charging duration corresponding to each constant current charging stage, the battery is controlled to perform constant current charging according to the charging current and charging duration corresponding to each constant current charging stage until the charging termination condition is reached, at which point charging ends.

[0058] Please see Figure 3 One embodiment of this application provides a battery charging method, including:

[0059] S310: Obtain the charging current corresponding to each constant current charging stage in the multiple constant current charging stages of the battery.

[0060] The charging current corresponding to each constant current charging stage is preset, and multiple constant current charging stages include at least two of these constant current charging stages.

[0061] In an optional embodiment, the plurality of constant current charging stages include at least a first constant current charging stage, a second constant current charging stage, and a third constant current charging stage. The first charging current (I1) corresponding to the first constant current charging stage is greater than the second charging current (I2) corresponding to the second constant current charging stage, and the second charging current (I2) is greater than the third charging current (I3) corresponding to the third constant current charging stage. That is, I1 > I2 > I3. Optionally, the value range of the first charging current (I1) is 3C to 4C, the value range of the second charging current (I2) is 1C to 1.5C, and the value range of the third charging current (I3) is 0.5C to 0.7C.

[0062] When controlling constant current charging of the battery, the charging is controlled in sequence from high current to low current to improve battery charging efficiency.

[0063] In this embodiment, the battery can be a non-aqueous lithium-ion battery, and the lithium-ion battery can include a positive electrode, a negative electrode, a separator, an electrolyte, and a casing.

[0064] The positive electrode sheet includes a positive current collector and a positive electrode coating, the positive electrode coating including the positive electrode material. The positive current collector is aluminum foil, and / or aluminum foil containing doped elements, and / or aluminum foil containing a surface coating. Doped elements include one or more of copper, silicon, magnesium, zinc, manganese, nickel, iron, titanium, chromium, and lithium. The surface coating includes one or more of amorphous carbon, silver, and gold. The positive electrode material is selected from lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate, lithium iron silicate, lithium cobalt oxide, nickel-cobalt-manganese ternary materials, nickel-manganese / cobalt-manganese / nickel-cobalt binary materials, lithium manganese oxide, and lithium-rich manganese-based materials, and more.

[0065] The diaphragm is a substrate diaphragm and / or a coated diaphragm. The substrate diaphragm includes polyethylene, polypropylene, or multilayer composite films thereof. The coated diaphragm includes a substrate diaphragm and a coating layer, wherein the coating layer is one or more of polyvinylidene fluoride, alumina, and boehmite.

[0066] The electrolyte comprises a solvent and a lithium salt. The solvent is selected from one or more of ethylene carbonate (EC), propylene carbonate (PC), propyl propionate (PP), diethyl carbonate (DEC), fluoroethylene carbonate (FEC), 1,3-propanesulfonate lactone (PS), dimethyl carbonate (DMC), and methyl ethyl carbonate (EMC). The lithium salt is selected from one or more of LiPF6, LiBF4, LiSbF6, LiClO4, LiCF3SO3, LiAlO4, LiAlCl4, Li(CF3SO2)2N, LiBOB, and LiDFOB.

[0067] The shell is selected from one or more of aluminum-plastic film, aluminum shell, and steel shell.

[0068] S320, for each constant current charging stage, the charging duration corresponding to the constant current charging stage is determined based on the charging current corresponding to the constant current charging stage and the rate of change of the solid electrolyte interface film thickness of the battery. The rate of change is obtained by monitoring the battery charging when the charging current corresponding to the constant current charging stage is controlled, and the rate of increase of the solid electrolyte interface film thickness corresponding to the rate of change exceeds the preset rate.

[0069] As the battery charges, a noticeable increase in the SEI (Sediment Integrated Layer) thickness can be observed. Initially, the SEI thickens slowly, but the rate of thickening increases significantly with charging time. There is a point of inflection in the SEI thickening rate. Before this point, the SEI thickness increases relatively slowly, while after this point, the rate of increase suddenly accelerates. In other words, the SEI thickness increase rate at this point of inflection exceeds a preset rate.

[0070] To prevent variations in the rate of SEI thickness growth, the charging duration of the constant-current charging phase needs to be controlled before a sudden increase in the SEI thickness growth rate. Therefore, the battery charging is controlled by the charging current corresponding to this constant-current charging phase, and the rate of growth is monitored during charging to determine the corresponding charging duration for each constant-current charging phase. Optionally, during battery charging, the SEI thickness is monitored in real-time using in-situ atomic force microscopy (AFM). The electronic device can synchronously generate the SEI thickness growth rate based on the real-time monitored SEI thickness and charging duration, and plot a diagram of the rate of growth based on this synchronously generated rate and charging duration. The rate of growth point can be determined from the diagram.

[0071] For example, Figure 4 This graph shows the change in the thickness of the solid electrolyte interphase (SEI) film of a battery over charging time when it is charged at a constant current with a certain charging current. Figure 4 As shown, the thickness of the solid electrolyte interfacial film in the battery does not change significantly within 0-14 minutes, but increases significantly after 14 minutes. Therefore, 14 minutes can be taken as the charging time corresponding to the constant current charging stage of constant current charging with this charging current. As long as the constant current charging stage is completed within the charging time, the thickness of the solid electrolyte interfacial film in the battery will not increase significantly.

[0072] In an optional embodiment, when determining the charging duration corresponding to the constant current charging stage, firstly, the correspondence between the charging duration and the rate of change of the solid electrolyte interface film thickness of the battery when the battery is controlled by the charging current corresponding to the constant current charging stage is determined. Then, based on the correspondence between the charging duration and the rate of change of the solid electrolyte interface film thickness, the charging duration when the rate of increase of the solid electrolyte interface film thickness is less than a preset thickness increase rate is determined, which is the charging duration corresponding to the constant current charging stage.

[0073] Assuming the charging time corresponding to the rate change point is Ta, and the charging time is ts, the correspondence between the charging time and the rate change point of the solid electrolyte interfacial film thickness increase in this battery can be understood as the relationship between the charging time ts and the charging time Ta corresponding to the rate change point. The charging time Ta corresponding to the rate change point refers to the charging time of the battery from the start of charging to the time corresponding to the rate change point.

[0074] For example, as described above, the multiple constant current charging stages include at least a first constant current charging stage, a second constant current charging stage, and a third constant current charging stage. For the first constant current charging stage (CC1 charging), the correspondence between the charging time and the rate of change of the solid electrolyte interface film thickness in the battery can be 0.8Ta1≤t s1 ≤Ta1, where t s1 Ta1 represents the charging time corresponding to the first constant current charging stage, and Ta2 represents the charging time corresponding to the rate change point monitored when the battery is charged with the first charging current (I1). For the second constant current charging stage (CC2 charging), the correspondence between the charging time and the rate change point of the solid electrolyte interface film thickness increase of the battery can be 0.8Ta2≤t s2 ≤Ta2, where t s2 Ta2 represents the charging time corresponding to the second constant current charging stage, and Ta3 represents the charging time corresponding to the rate change point monitored when the battery is charged with the second charging current (I2). For the third constant current charging stage (CC3 charging), the correspondence between the charging time and the rate change point of the solid electrolyte interface film thickness increase of the battery can be 0.8Ta3≤t. s3 ≤Ta3, where t s3 Ta3 represents the charging time corresponding to the third constant current charging stage, and Ta3 represents the charging time corresponding to the point of rate change monitored when the battery is charged with the third charging current (I3). In an optional embodiment, when I1 > I2 > I3, t s3 >t s1 , and t s3 >t s2 .

[0075] S330 controls the battery to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage, until the charging termination condition is met, at which point the charging ends.

[0076] In step S310, multiple constant current charging stages of the battery are obtained. For each constant current charging stage, the charging time corresponding to the constant current charging stage can be determined in step S320. Thus, the charging time corresponding to each constant current charging stage in the multiple constant current charging stages of the battery is finally obtained.

[0077] The charging current corresponding to each constant current charging stage has already been obtained. When controlling the battery to perform constant current charging, the battery is controlled to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage. During the constant current charging process, when the cutoff voltage is reached, the battery is controlled to perform constant voltage charging. During the constant voltage charging process, the charging current continuously decreases. When the cutoff current is reached, the charging termination condition is met, and charging ends. The cutoff voltage and cutoff current can be set according to actual needs, and this embodiment does not limit them.

[0078] Please see Figure 5 The diagram shown illustrates the current flow during battery charging, including multiple constant current charging stages (such as...). Figure 5 The CC charging shown includes a first constant current charging stage (CC1 charging), a second constant current charging stage (CC2 charging), and a third constant current charging stage (CC3 charging) as described above. Therefore, when controlling the battery, the first charging current (I1) and the first charging duration (t) corresponding to the first constant current charging stage are first determined. s1 The battery is controlled to undergo constant current charging. At the end of the first constant current charging phase, the second charging current (I2) and the corresponding second charging duration (t) are used to control the battery to perform constant current charging. s2 The battery is controlled to undergo constant current charging. At the end of the second constant current charging stage, the third charging current (I3) and the corresponding third charging duration (t) are used to control the battery to undergo constant current charging. s3 The battery is controlled to undergo constant current charging. If the cutoff voltage is reached during the third constant current charging stage (e.g., ...), the battery is controlled to undergo constant current charging. Figure 5 Chinese cv If the voltage at a given time is reached, the battery is controlled to undergo constant voltage charging (CV charging). During constant voltage charging, when the cutoff current (e.g., ...) is reached... Figure 5 Chinese f When the current at a given moment is reached, charging ends.

[0079] For example, Figure 6 The graph shows the relationship between the rate of change of battery internal resistance and the number of battery cycles for different charging methods, as shown below. Figure 6 As shown, curve 1 represents the relationship between the rate of change of battery internal resistance and the number of cycles when charging using the battery charging method provided in this application embodiment. Curve 2 represents the relationship between the rate of change of battery internal resistance and the number of cycles when a high-current charging stage is performed first, followed by a low-current charging stage, and the actual charging time of the high-current charging stage exceeds the total charging time. Curve 3 represents the relationship between the rate of change of battery internal resistance and the number of cycles when charging in stages, and the actual charging time of the high-current charging stage exceeds the total charging time. Figure 6As shown, curves 2 and 3 show a significant increase in the rate of change of battery internal resistance as the number of cycles increases due to the presence of charging stages where the actual charging time exceeds the charging time. In contrast, curve 1 shows no significant change in the rate of change of battery internal resistance because the actual charging time in each charging stage does not exceed the charging time. This improves the cycle performance of the battery and thus extends its lifespan.

[0080] In summary, the battery charging method provided in this embodiment includes: acquiring the charging current corresponding to each constant current charging stage in a plurality of constant current charging stages of the battery; for each constant current charging stage, determining the charging duration corresponding to the constant current charging stage based on the charging current corresponding to the constant current charging stage and the rate of change of the thickness of the solid electrolyte interface film of the battery, wherein the rate of change is monitored when the battery is charged by controlling the charging current corresponding to the constant current charging stage, and the thickness growth rate of the solid electrolyte interface film corresponding to the rate of change exceeds a preset rate; controlling the battery to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage until the charging termination condition is reached, and then ending the charging.

[0081] Understandably, as battery charging progresses, the SEI (Sediment Injection) of the battery noticeably thickens. Initially, the SEI thickens slowly, but this rate increases significantly with charging time. There is a point of inflection in the SEI thickening rate; before this point, the SEI thickness increases at a relatively low rate, while after this point, the rate of increase abruptly increases. That is, the SEI thickness increase rate at this point exceeds a preset rate. For any constant-current charging stage, using this point of inflection as a dividing point, the charging time before this point is set as the constant-current charging time for that stage. This effectively suppresses excessive SEI growth. Therefore, the method provided in this application can maintain a reasonable residual electrolyte level inside the battery, reducing the rate of increase in internal resistance, maintaining a low internal resistance value, and avoiding adverse effects on the battery's cycle performance, thereby improving battery lifespan. Furthermore, it can significantly shorten the battery charging time.

[0082] Please see Figure 7 One embodiment of this application provides a battery control system 10, including:

[0083] The acquisition module 11 is used to acquire the charging current corresponding to each constant current charging stage in the multiple constant current charging stages of the battery.

[0084] The processing module 12 is used to determine the charging time corresponding to each constant current charging stage based on the charging current corresponding to the constant current charging stage and the rate of change of the solid electrolyte interface film thickness of the battery. The rate of change is obtained by monitoring the charging of the battery when the charging current corresponding to the constant current charging stage is controlled, and the rate of increase of the solid electrolyte interface film thickness corresponding to the rate of change exceeds a preset rate.

[0085] The control module 13 is used to control the battery to perform constant current charging according to the charging current and charging time corresponding to each constant current charging stage, until the charging termination condition is reached and the charging ends.

[0086] The processing module 12 is specifically used to determine the correspondence between the charging time and the rate of change of the solid electrolyte interface film thickness of the battery when the battery is charged at a constant current with the charging current corresponding to the constant current charging stage; based on the correspondence between the charging time and the rate of change of the solid electrolyte interface film thickness, the charging time when the rate of increase of the solid electrolyte interface film thickness is less than the preset thickness increase rate is determined as the charging time corresponding to the constant current charging stage.

[0087] The multiple constant current charging stages include at least a first constant current charging stage, a second constant current charging stage, and a third constant current charging stage. The first charging current corresponding to the first constant current charging stage is greater than the second charging current corresponding to the second constant current charging stage, and the second charging current is greater than the third charging current corresponding to the third constant current charging stage.

[0088] The control module 13 is specifically used to control the battery to perform constant current charging according to the first charging current and the first charging duration corresponding to the first constant current charging stage; to control the battery to perform constant current charging according to the second charging current and the second charging duration corresponding to the second constant current charging stage; and to control the battery to perform constant current charging according to the third charging current and the third charging duration corresponding to the third constant current charging stage.

[0089] The first charging current ranges from 3C to 4C, the second charging current ranges from 1C to 1.5C, and the third charging current ranges from 0.5C to 0.7C.

[0090] The control module 13 is specifically used to control the battery to perform constant current charging according to the charging current and charging time corresponding to each constant current charging stage, until the cutoff voltage is reached, and then control the battery to perform constant voltage charging; during the process of controlling the battery to perform constant voltage charging, when the cutoff current is reached, the charging termination condition is met, and the charging ends.

[0091] Please see Figure 8One embodiment of this application also provides an electronic device 20, including a processor 21 and a memory 22 communicatively connected to the processor 21. The memory 22 stores computer-executable instructions, and the processor 21 executes the computer-executable instructions stored in the memory 22 to implement the battery charging method as provided in any of the above embodiments.

[0092] An embodiment of this application also provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, are used to implement the battery charging method provided in any of the preceding embodiments.

[0093] An embodiment of this application also provides a computer program product, including a computer program that, when executed by a processor, implements the battery charging method as provided in any of the preceding embodiments.

[0094] It should be noted that the aforementioned computer-readable storage media can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM), etc. It can also be various electronic devices that include one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc.

[0095] It should be noted that, in this document, 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 a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0096] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0097] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, 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) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0098] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0099] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0100] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0101] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method of charging a battery, characterized by, include: Obtain the charging current corresponding to each constant current charging stage in the multiple constant current charging stages of the battery; For each constant current charging stage, a correspondence is determined between the charging duration and the rate of change of the solid electrolyte interfacial film thickness when the battery is charged at a constant current with the charging current corresponding to that stage. Based on this correspondence, the charging duration when the rate of increase of the solid electrolyte interfacial film thickness is less than a preset rate of increase is determined as the charging duration corresponding to the constant current charging stage. The rate of change is monitored when the battery is charged with the charging current corresponding to that stage, and the rate of increase of the solid electrolyte interfacial film thickness at the rate of change exceeds the preset rate. The rate of change indicates that the rate of increase of the solid electrolyte interfacial film thickness gradually decreases. The critical point for the transition from a slow growth phase to a rapid growth phase is defined. Before this critical point, the growth rate of the solid electrolyte interface film thickness is less than a preset rate. At and after this critical point, the growth rate of the solid electrolyte interface film thickness exceeds the preset rate. The multiple constant current charging phases include at least a first constant current charging phase, a second constant current charging phase, and a third constant current charging phase. The first charging current corresponding to the first constant current charging phase is greater than the second charging current corresponding to the second constant current charging phase, and the second charging current is greater than the third charging current corresponding to the third constant current charging phase. The first charging current ranges from 3C to 4C, the second charging current ranges from 1C to 1.5C, and the third charging current ranges from 0.5C to 0.7C. Based on the charging current and charging duration corresponding to each constant current charging stage, the battery is controlled to perform constant current charging until the charging termination condition is met, at which point the charging ends.

2. The method of claim 1, wherein, The step of controlling the battery to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage includes: Based on the first charging current and the first charging duration corresponding to the first constant current charging stage, the battery is controlled to perform constant current charging. Based on the second charging current and the second charging duration corresponding to the second constant current charging stage, the battery is controlled to perform constant current charging. The battery is controlled to perform constant current charging based on the third charging current and the third charging duration corresponding to the third constant current charging stage.

3. The method of claim 1, wherein, The step of controlling the battery to perform constant current charging based on the charging current and charging duration corresponding to each constant current charging stage, until the charging termination condition is met, and then ending the charging process includes: Based on the charging current and charging duration corresponding to each constant current charging stage, the battery is controlled to perform constant current charging until the cutoff voltage is reached, at which point the battery is controlled to perform constant voltage charging. During the constant voltage charging process of the battery, when the cutoff current is reached, the charging termination condition is met, and the charging ends.

4. A battery control system characterized by comprising: include: The acquisition module is used to acquire the charging current corresponding to each constant current charging stage in the multiple constant current charging stages of the battery. The processing module is configured to, for each constant current charging stage, determine the correspondence between the charging duration and the rate of change of the solid electrolyte interfacial film thickness growth when the battery is controlled by the charging current corresponding to the constant current charging stage; based on the correspondence between the charging duration and the rate of change of the solid electrolyte interfacial film thickness growth, determine the charging duration when the rate of increase of the solid electrolyte interfacial film thickness is less than a preset rate of increase, which is the charging duration corresponding to the constant current charging stage. The rate of change is obtained by monitoring when the battery is charged by the charging current corresponding to the constant current charging stage, and the rate of increase of the solid electrolyte interfacial film thickness at the rate of change exceeds the preset rate; the rate of change characterizes the rate of increase of the solid electrolyte interfacial film thickness. The thickness of the solid electrolyte interface film increases at a critical point, transitioning from a slow growth phase to a rapid growth phase. Before this critical point, the growth rate of the solid electrolyte interface film thickness is less than a preset rate; at and after this critical point, the growth rate of the solid electrolyte interface film thickness exceeds the preset rate. The multiple constant current charging phases include at least a first constant current charging phase, a second constant current charging phase, and a third constant current charging phase. The first charging current corresponding to the first constant current charging phase is greater than the second charging current corresponding to the second constant current charging phase, and the second charging current is greater than the third charging current corresponding to the third constant current charging phase. The first charging current ranges from 3C to 4C, the second charging current ranges from 1C to 1.5C, and the third charging current ranges from 0.5C to 0.7C. The control module is used to control the battery to perform constant current charging according to the charging current and charging duration corresponding to each constant current charging stage, until the charging termination condition is reached and the charging ends.

5. An electronic device, comprising: Includes a processor and a memory communicatively connected to the processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory to implement the method as described in any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1 to 3.

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