Battery charging control method and device, electronic equipment and storage medium

Abstract

The application provides a battery charging control method and device, electronic equipment and a storage medium. The method comprises: obtaining at least the proportion of the initial charge capacity of a lithium ion battery to the rated capacity; when the proportion is less than or equal to a preset proportion, determining the charging current of the lithium ion battery during second stage charging according to the rated capacity, the capacity value and the ambient temperature; determining the charging current of the lithium ion battery during first stage charging according to the charging current during the second stage charging and a preset current relationship; determining the charging duration of the lithium ion battery during the first stage charging; performing first stage charging of the lithium ion battery, and performing second stage charging of the lithium ion battery until a charging end condition is reached, and then ending the charging. The method of the application can solve the problem of how to ensure efficient charging of a lithium ion battery containing a silicon-based material in the negative electrode sheet while maintaining good cycle performance.

Description

Technical Field

[0001] This application relates to battery charging control technology, and more particularly to a battery charging control method, device, electronic device, and storage medium. Background Technology

[0002] Currently, the materials used in commercially available lithium-ion batteries are generally carbon-based materials such as graphite and silicon-based materials. Compared to carbon-based materials like graphite, silicon-based materials can store more lithium ions per unit mass or unit volume. Therefore, negative electrode sheets containing silicon-based materials are lighter and thinner. Correspondingly, lithium-ion batteries containing this negative electrode sheet can have higher energy density and faster charging speeds.

[0003] However, for lithium-ion batteries with silicon-based negative electrodes, efficient charging remains difficult to control effectively. On one hand, charging lithium-ion batteries with high current and for extended periods can easily cause the silicon-based material structure to crack, making it difficult to achieve good cycle performance. On the other hand, reducing the charging current slows down the charging speed and prolongs the charging time.

[0004] Therefore, for lithium-ion batteries with silicon-based negative electrodes, ensuring good cycle performance while charging efficiently remains a challenge. Summary of the Invention

[0005] This application provides a battery charging control method, device, electronic device, and storage medium to solve the problem of how to ensure good cycle performance of lithium-ion batteries with silicon-based negative electrode materials while charging efficiently.

[0006] On one hand, this application provides a battery charging control method, including:

[0007] At least the rated capacity of the lithium-ion battery, the capacity ratio of silicon-based materials in the lithium-ion battery, the ambient temperature, the capacity value corresponding to the unit electrode area, and the ratio of the initial charge of the lithium-ion battery to the rated capacity should be obtained.

[0008] When the ratio is less than or equal to a preset ratio, the charging current of the lithium-ion battery during the second stage of charging is determined based on the rated capacity, the capacity value, and the ambient temperature; and the charging current of the lithium-ion battery during the first stage of charging is determined based on the charging current during the second stage of charging and the preset current relationship; and the charging time of the lithium-ion battery during the first stage of charging is determined based on the rated capacity, the capacity ratio, and the charging current during the first stage of charging.

[0009] The lithium-ion battery is charged in the first stage based on the charging current and charging time during the first stage of charging, and in the second stage based on the charging current during the second stage of charging, until the charging end condition is met, at which point the charging ends.

[0010] In one embodiment, determining the charging current of the lithium-ion battery during the second stage of charging based on the rated capacity, the capacity value, and the ambient temperature includes:

[0011] Based on the capacity value and the ambient temperature, the comparison parameters are determined, and based on the comparison parameters and a preset first value, the first parameter and the second parameter are determined.

[0012] A first limit is determined based on the first parameter and the rated capacity, and a second limit is determined based on the second parameter and the rated capacity.

[0013] Based on the first limit and the second limit, the charging current during the second stage of charging is determined to be within the charging range.

[0014] Within the charging range of the charging current during the second stage of charging, any charging current is selected as the charging current during the second stage of charging.

[0015] In one embodiment, determining the charging current of the lithium-ion battery during the first stage of charging based on the charging current during the second stage of charging and a preset current relationship includes:

[0016] The third limit is determined based on the preset second value in the preset current relationship and the charging current during the second stage of charging;

[0017] The fourth limit is determined based on the preset third value in the preset current relationship and the charging current during the second stage of charging.

[0018] The charging range of the lithium-ion battery during the first stage of charging is determined based on the third and fourth limits.

[0019] Within the charging range of the charging current during the first stage of charging, any charging current is selected as the charging current during the first stage of charging.

[0020] In one embodiment, determining the charging duration of the lithium-ion battery during the first stage of charging based on the rated capacity, the capacity percentage, and the charging current during the first stage of charging includes:

[0021] Obtain the preset fourth value and the preset fifth value, and obtain the coefficient of the capacity ratio;

[0022] A fifth limit is determined based on the capacity ratio coefficient, the preset fourth value, the rated capacity, and the charging current during the first stage of charging; and a sixth limit is determined based on the capacity ratio coefficient, the preset fifth value, the rated capacity, and the charging current during the first stage of charging.

[0023] Based on the fifth and sixth limits, the charging time range of the lithium-ion battery during the first stage of charging is determined, and any duration within the range is selected as the charging time of the lithium-ion battery during the first stage of charging.

[0024] In one embodiment, determining the fifth limit value based on the capacity ratio coefficient, the preset fourth value, the rated capacity, and the charging current during the first stage of charging includes:

[0025] The first denominator value is determined based on the capacity ratio coefficient, the preset fourth value, and the rated capacity. The fifth limit value is determined using the charging current of the ion battery during the first stage of charging as the numerator value.

[0026] The determination of the sixth limit value based on the capacity ratio coefficient, the preset fifth value, the rated capacity, and the charging current during the first stage of charging includes:

[0027] The second denominator value is determined based on the capacity ratio coefficient, the preset fifth value, and the rated capacity. The sixth limit value is determined using the charging current of the ion battery during the first stage of charging as the numerator value.

[0028] In one embodiment, the charging current of the lithium-ion battery during the first stage of charging is greater than the charging current of the lithium-ion battery during the second stage of charging.

[0029] The capacity ratio is greater than or equal to 0.1 and less than or equal to 0.5;

[0030] The capacity value is greater than or equal to 1.5 mA per square centimeter and less than or equal to 3.5 mA per square centimeter;

[0031] The ambient temperature is greater than or equal to 5 degrees Celsius and less than or equal to 50 degrees Celsius.

[0032] In one embodiment, obtaining the initial charge capacity of the lithium-ion battery relative to its rated capacity includes:

[0033] Obtain the initial charging voltage of the lithium-ion battery;

[0034] Based on the initial charging voltage and the correspondence between charge and voltage, the proportion of the initial charge to the rated capacity of the lithium-ion battery is determined.

[0035] In one embodiment, the preset ratio is determined based on the capacity ratio.

[0036] In one embodiment, ending charging when the charging end condition is met includes:

[0037] When the cutoff voltage is reached, the lithium-ion battery is controlled to be charged at a constant voltage until the cutoff current is reached, at which point the charging end condition is met and the charging ends. The cutoff current is less than the charging current during the second stage of charging.

[0038] After the charging process ends, the method further includes:

[0039] After a first preset time of rest, the lithium-ion battery is discharged at a preset current until the discharge cutoff voltage is reached, and then it is rested for a second preset time.

[0040] On the other hand, this application provides a battery charging control device, including:

[0041] The acquisition module is used to acquire at least the rated capacity of the lithium-ion battery, the capacity ratio of silicon-based materials in the lithium-ion battery, the ambient temperature, the capacity value corresponding to the unit electrode area, and the ratio of the initial charge of the lithium-ion battery to the rated capacity.

[0042] The processing module is configured to: determine the charging current of the lithium-ion battery during the second stage of charging based on the rated capacity, the capacity value, and the ambient temperature when the ratio is less than or equal to a preset ratio; determine the charging current of the lithium-ion battery during the first stage of charging based on the charging current during the second stage of charging and a preset current relationship; and determine the charging duration of the lithium-ion battery during the first stage of charging based on the rated capacity, the capacity ratio, and the charging current during the first stage of charging.

[0043] The charging control module is used to perform the first stage charging of the lithium-ion battery based on the charging current and charging time during the first stage charging, and to perform the second stage charging of the lithium-ion battery based on the charging current during the second stage charging, until the charging end condition is met, and then the charging ends.

[0044] On the other hand, this application provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0045] The memory stores computer-executed instructions;

[0046] The processor executes computer execution instructions stored in the memory to implement the battery charging control method as described in the first aspect.

[0047] On the other hand, this application provides a computer-readable storage medium storing computer-executable instructions that, when executed, cause a computer to perform the battery charging control method as described in the first aspect.

[0048] On the other hand, this application provides a computer program product, including a computer program that, when executed by a processor, implements the battery charging control method as described in the first aspect.

[0049] The battery charging control method provided in the embodiments of this application acquires a series of characteristic parameters of the lithium-ion battery itself, such as the rated capacity, the capacity ratio of silicon-based material in the lithium-ion battery, the ambient temperature, the capacity value corresponding to a unit electrode area, and the ratio of the initial charge of the lithium-ion battery to its rated capacity, as well as environmental parameters. Then, based on the characteristic parameters of the battery itself, a constant current for the battery during the second stage of charging is determined, and based on the constant current during the second stage of charging, a constant current and charging duration for the first stage of charging are determined.

[0050] When charging lithium-ion batteries, this method takes into account the battery's inherent characteristics and environmental conditions, rather than simply pre-setting the current based on voltage and the battery's remaining state of charge (SOC). This improves charging speed and efficiency. Experimental results show that, while maintaining similar charging times, the method provided in this application achieves higher capacity retention and lower thickness expansion, significantly improving the cycle performance of lithium-ion batteries with silicon-based negative electrodes. Therefore, the method provided in this application addresses the challenge of ensuring good cycle performance while efficiently charging lithium-ion batteries with silicon-based negative electrodes. Attached Figure Description

[0051] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0052] Figure 1 A schematic diagram illustrating an application scenario of the battery charging control method provided in this application;

[0053] Figure 2 A schematic flowchart of a battery charging control method provided in one embodiment of this application;

[0054] Figure 3 A schematic diagram of a battery charging control device provided in one embodiment of this application;

[0055] Figure 4A schematic diagram of an electronic device provided for one embodiment of this application.

[0056] The accompanying drawings have illustrated specific embodiments of this disclosure, 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 concepts of this disclosure to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0057] 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 numerals 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 disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0058] 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.

[0059] Currently, the materials used in commercially available lithium-ion batteries are generally carbon-based materials such as graphite and silicon-based materials. Compared to carbon-based materials like graphite, silicon-based materials can store more lithium ions per unit mass or unit volume. Therefore, negative electrode sheets containing silicon-based materials are lighter and thinner. Correspondingly, lithium-ion batteries containing this negative electrode sheet can have higher energy density and faster charging speeds.

[0060] However, for lithium-ion batteries with silicon-based negative electrodes, efficient charging remains difficult to control effectively. On one hand, charging lithium-ion batteries with high current and for extended periods can easily cause the silicon-based material structure to crack, making it difficult to achieve good cycle performance. On the other hand, reducing the charging current slows down the charging speed and prolongs the charging time.

[0061] Existing methods for controlling battery charging typically preset the charging current based on voltage or the battery's remaining state of charge (SOC) range, without fully considering the impact of factors such as ambient temperature, battery areal density, and silicon capacity ratio on the charging rate and time. Furthermore, the charging time at high rates is significantly affected by the initial SOC, failing to fully improve the battery's charging speed.

[0062] Therefore, for lithium-ion batteries with silicon-based negative electrodes, ensuring good cycle performance while charging efficiently remains a challenge.

[0063] Based on this, this application provides a battery charging control method, apparatus, electronic device, and storage medium. The battery charging control method includes: acquiring at least the rated capacity of a lithium-ion battery, the capacity ratio of silicon-based material in the lithium-ion battery, the ambient temperature, the capacity value corresponding to a unit electrode area, and the ratio of the initial charge of the lithium-ion battery to its rated capacity; when the ratio is less than or equal to a preset ratio, determining the charging current of the lithium-ion battery during a second stage of charging based on the rated capacity, the capacity value, and the ambient temperature; determining the charging current of the lithium-ion battery during a first stage of charging based on the charging current during the second stage of charging and a preset current relationship; determining the charging duration of the lithium-ion battery during the first stage of charging based on the rated capacity, the capacity ratio, and the charging current during the first stage of charging; performing a first stage of charging of the lithium-ion battery based on the charging current and charging duration during the first stage of charging; and performing a second stage of charging of the lithium-ion battery based on the charging current during the second stage of charging, until the cutoff voltage and cutoff current are reached, at which point charging ends.

[0064] When charging lithium-ion batteries, this method takes into account the battery's inherent characteristics and environmental conditions, rather than simply pre-setting the current based on voltage and the battery's state of charge (SOC) range. This improves charging speed and charging efficiency. Experimental verification shows that, while maintaining similar charging times, the method provided in this application achieves higher capacity retention and lower thickness expansion, significantly improving the cycle performance of lithium-ion batteries with silicon-based negative electrodes. Therefore, the method provided in this application addresses the challenge of ensuring good cycle performance while maintaining efficient charging for lithium-ion batteries with silicon-based negative electrodes.

[0065] The battery charging control 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 1This is a schematic diagram illustrating the application of the battery charging control method provided in this application. In the diagram, the electronic device acquires at least the rated capacity of the lithium-ion battery, the capacity ratio of silicon-based material in the lithium-ion battery, the ambient temperature, the capacity value corresponding to a unit electrode area, and the initial charge of the lithium-ion battery relative to its rated capacity. Then, based on the rated capacity, the capacity value, and the ambient temperature, it determines the charging current for the lithium-ion battery during the second stage of charging. Based on the charging current during the second stage of charging and a preset current relationship, it determines the charging current for the lithium-ion battery during the first stage of charging. Based on the rated capacity, the capacity ratio, and the charging current during the first stage of charging, it determines the charging duration for the lithium-ion battery during the first stage of charging. Finally, it performs the first stage of charging of the lithium-ion battery based on the charging current and charging duration during the first stage of charging, and performs the second stage of charging of the lithium-ion battery based on the charging current during the second stage of charging, until the charging termination condition is met, at which point charging ends.

[0066] Please see Figure 2 One embodiment of this application provides a battery charging control method, the method comprising:

[0067] S210, at least obtain the rated capacity of the lithium-ion battery, the capacity ratio of silicon-based materials in the lithium-ion battery, the ambient temperature, the capacity value corresponding to the unit electrode area, and the ratio of the initial charge of the lithium-ion battery to the rated capacity.

[0068] In one optional embodiment, the lithium-ion battery includes a negative electrode, a positive electrode, a separator, an electrolyte, and a casing. The separator is located between the negative electrode and the positive electrode. The negative electrode has a negative electrode coating comprising a negative electrode active material. The negative electrode active material comprises a silicon-based material. The silicon-based material includes at least one of silicon-oxygen composite materials, lithium-doped silicon-oxygen composite materials, magnesium-doped silicon-oxygen composite materials, and silicon-carbon composite materials.

[0069] The positive electrode consists of aluminum foil (positive current collector) and a positive electrode coating on its surface. The coating comprises lithium cobalt oxide, carbon black, carbon nanotubes, and polyvinylidene fluoride. The mass percentages of lithium cobalt oxide are 97.0%, carbon black 1.0%, carbon nanotubes 0.4%, and polyvinylidene fluoride 1.6%. The areal density of the positive electrode coating is 17.0 mg / cm³. 2 The total area of ​​the positive electrode coating is 1405.5 cm². 2 .

[0070] The negative electrode consists of copper foil (negative electrode current collector) and a negative electrode coating on its surface. The negative electrode coating comprises graphite, lithium-doped silicon-oxygen composite material, carbon black, carbon nanotubes, lithium carboxymethyl cellulose, and styrene-butadiene rubber. The mass percentages are: graphite 89.3%, lithium-doped silicon-oxygen composite material 6.7%, carbon black 0.8%, carbon nanotubes 0.1%, lithium carboxymethyl cellulose 1.0%, and styrene-butadiene rubber 2.1%. The areal density of the negative electrode coating is 7.0 mg / cm³. 2 .

[0071] The lithium-ion battery has a wound structure with an initial thickness of 50% charge. The battery is 80mm long, 65mm wide, and 3.7mm thick.

[0072] When obtaining the rated capacity Q (in Ah) of a lithium-ion battery, the operating voltage range of the battery is determined to be 3V to 4.48V. First, the lithium-ion battery is charged at a constant current of 800mA until the voltage is ≥4.48V. Then, it is charged at a constant voltage of 4.48V until the current is ≤400mA. Finally, it is discharged at a constant current of 800mA until the voltage is ≤3V, resulting in a rated capacity Q of 4000mAh.

[0073] Dividing the rated capacity Q by the total area of ​​the positive electrode coating yields a capacity value ρ per unit electrode area of ​​2.846 mAh / cm². 2 .

[0074] The capacity ratio η of silicon-based materials can be obtained as follows: The lithium-ion battery is charged at a constant current of 800mA until the voltage is ≥4.48V, then charged at a constant voltage of 4.48V until the current is ≤400mA. Subsequently, the lithium-ion battery is discharged at a constant current of 200mA until the voltage is ≤3V. This yields a curve of discharge voltage y versus depth of discharge x (where x is the ratio of cumulative discharge capacity to rated capacity). The first derivative of y with respect to x is taken, yielding the curve of dy / dx with respect to x. Let xmax be the x corresponding to the maximum value of dy / dx. Using xmax as the starting point, and the x corresponding to the first minimum value of dy / dx along the direction of increasing x as xmin, we obtain η = 1 - xmin. The capacity ratio η of silicon-based materials in this lithium-ion battery is 0.206.

[0075] The initial charge capacity ratio S0 of a lithium-ion battery can be determined by obtaining the initial charging voltage U0 of the lithium-ion battery. Then, based on the initial charging voltage U0 and the correspondence between charge capacity and voltage, the initial charge capacity ratio S0 of the lithium-ion battery can be determined.

[0076] In an optional embodiment, the capacity percentage η is greater than or equal to 0.1 and less than or equal to 0.5. The capacity value ρ is greater than or equal to 1.5 mA per square centimeter (mAh / cm²). 2 ), and less than or equal to 3.5 mAh / cm 2 The ambient temperature T is greater than or equal to 5 degrees Celsius (°C) and less than or equal to 50 degrees Celsius (°C).

[0077] S220, when the ratio is less than or equal to a preset ratio, the charging current of the lithium-ion battery during the second stage of charging is determined based on the rated capacity, the capacity value, and the ambient temperature; and the charging current of the lithium-ion battery during the first stage of charging is determined based on the charging current during the second stage of charging and the preset current relationship; and the charging time of the lithium-ion battery during the first stage of charging is determined based on the rated capacity, the capacity ratio, and the charging current during the first stage of charging.

[0078] The preset ratio is determined based on the capacity ratio η, where S0 ≤ 0.12η + 0.49. When η = 0.206, the initial charge ratio S0 to the rated capacity must satisfy S0 ≤ 51.5%.

[0079] When the ratio S0 determined based on the initial charging voltage is less than or equal to the preset ratio, the charging current of the lithium-ion battery during the second stage of charging is determined based on the rated capacity, the capacity value, and the ambient temperature.

[0080] Specifically, based on the capacity value and the ambient temperature, the comparison parameter α is determined. α = (0.0007T + 0.0179) × (T + 273)ρ -3 +0.0027T, where T represents the ambient temperature and ρ represents the capacity value. Then, based on this comparison parameter and a preset first value, a first parameter and a second parameter are determined. For example, the preset first value is 0.2, the first parameter is α-0.2, and the second parameter is α+0.2. Then, based on the first parameter and the rated capacity, a first limit is determined, and based on the second parameter and the rated capacity, a second limit is determined. The first limit is (α-0.2)×Q, and the second limit is (α+0.2)×Q.

[0081] Based on the first and second limits, the charging current range for the second stage of charging is determined. That is, (α-0.2)×Q≤I2≤(α+0.2)×Q. Within the charging range of the charging current for the second stage of charging, any charging current is selected as the charging current I2 for the second stage of charging.

[0082] After confirming the charging current I2 during the second stage of charging, the charging current I1 during the first stage of charging is determined based on the relationship between the charging current during the second stage and the preset current. Optionally, the charging current I1 during the first stage of charging is greater than the charging current I2 during the second stage of charging. Controlling battery charging in a manner that reduces current from high to low can improve battery charging efficiency.

[0083] Specifically, a third limit is determined based on a preset second value in the preset current relationship and the charging current I2 during the second stage of charging. A fourth limit is determined based on a preset third value in the preset current relationship and the charging current I2 during the second stage of charging. Optionally, the preset second value in the preset current relationship is 1.5, the preset third value in the preset current relationship is 3, the third limit is 1.5I2, and the fourth limit is 3I2.

[0084] The charging range of the lithium-ion battery's charging current during the first stage of charging is determined based on the third and fourth limits. 1.5I2≤I1≤3I2. Within this charging range, any charging current is selected as the charging current I1 for the first stage of charging.

[0085] After determining the charging current I1 during the first stage of charging, the charging time of the lithium-ion battery during the first stage of charging is determined based on the rated capacity, the capacity ratio, and the charging current during the first stage of charging.

[0086] Specifically, the system obtains a preset fourth value and a preset fifth value, as well as a coefficient for the capacity percentage. Optionally, the preset fourth value is 0.08, the preset fifth value is 0.13, and the coefficient for the capacity percentage is 0.13.

[0087] The fifth limit is determined based on the capacity ratio coefficient, the preset fourth value, the rated capacity, and the charging current during the first stage of charging. Specifically, the first denominator is determined based on the capacity ratio coefficient, the preset fourth value, and the rated capacity, and the fifth limit is determined using the charging current of the ion battery during the first stage of charging as the numerator. The fifth limit is (0.13η+0.08)Q / I1.

[0088] Furthermore, a sixth limit is determined based on the capacity ratio coefficient, the preset fifth value, the rated capacity, and the charging current during the first stage of charging. Specifically, a second denominator value is determined based on the capacity ratio coefficient, the preset fifth value, and the rated capacity, and the sixth limit is determined using the charging current during the first stage of charging of the ion battery as the numerator value. The sixth limit is (0.13η+0.13)Q / I1.

[0089] Based on the fifth and sixth limits, the charging time range of the lithium-ion battery during the first stage of charging is determined. (0.13η+0.08)Q / I1≤t1≤(0.13η+0.13)Q / I1. Any duration within this range is selected as the charging time of the lithium-ion battery during the first stage of charging.

[0090] S230 performs a first-stage charging of the lithium-ion battery based on the charging current and charging time during the first stage of charging, and performs a second-stage charging of the lithium-ion battery based on the charging current during the second stage of charging, until the charging end condition is met, and then ends the charging process.

[0091] The charging process for lithium-ion batteries is divided into two stages: a first-stage charging and a second-stage charging. In the first stage, the lithium-ion battery is charged based on the charging current and duration of the first-stage charging. In the second stage, the lithium-ion battery is charged based on the charging current of the second-stage charging. When the cutoff voltage is reached, the lithium-ion battery is charged at a constant voltage until the cutoff current is reached, thus ending the charging process.

[0092] The duration of the second-stage charging is not calculated in advance; it ends when the cutoff voltage and cutoff current are reached. The cutoff voltage is a constant voltage U2, and the cutoff current is I3, which is less than the charging current during the second-stage charging, i.e., I3 < I2. Optionally, the cutoff current I3 = 2A.

[0093] The electronic device includes a first monitoring module, a second monitoring module, a calculation module, a first control module, a second control module, and a third control module. The first monitoring module obtains the ambient temperature T at the initial charging stage. The second monitoring module obtains the initial charging voltage U0 and, according to a predetermined S0-U0 correspondence, obtains the initial charge-to-rated capacity ratio S0. The calculation module determines the specific values ​​of I2, I1, and t1 according to the calculation methods provided above.

[0094] The first control module is used to control the charging device to charge the lithium-ion battery according to the first constant current charging step. The first constant current charging step controls the charging by using the charging current I1 and the charging time t1 during the first stage of charging.

[0095] The second control module is used to control the charging device to charge the lithium-ion battery according to the second constant current charging step. The second constant current charging step is to control the charging with the charging current I2 during the second stage of charging.

[0096] The third control module controls the charging equipment to charge the lithium-ion battery according to a constant voltage charging procedure. This constant voltage charging procedure is based on a constant voltage U2 = 4.48V. Charging ends when the cutoff current I3 is reached.

[0097] In an optional embodiment, after charging ends when the cutoff voltage and cutoff current are reached, the battery is left to stand for a first preset time, then discharged at a preset current until the discharge cutoff voltage is reached, and then left to stand for a second preset time. Optionally, the first preset time is 0.25 hours (h), the preset current is 4A, the discharge cutoff voltage is 3V, and the second preset time is 0.25h. The third control module is used to control battery charging according to a constant voltage U2 = 4.48V. When the cutoff current I3 is reached, the battery is left to stand for 0.25h, then discharged at a preset current of 4A. When the discharge cutoff voltage 3V is reached, the battery is left to stand for 0.25h.

[0098] The following is an example of a charge-discharge cycle test performed according to a battery charging control method.

[0099] First, charging is performed using a first constant current charging step, where the charging current during the first stage is I1 = 2.3I2 = 12.1A, and the charging time is t1 = 0.527 / I1 = 0.044h. Then, charging is performed using a second constant current charging step, where the charging current during the second stage is I2 = 5.24A, and the cutoff voltage is U2 = 4.48V. Next, charging is performed using a constant voltage charging step, where the constant voltage is U2 = 4.48V, and the cutoff current is I3 = 2A, followed by a resting period of 0.25h. Finally, discharging is performed using a preset current of 4A, with a cutoff voltage of 3V, followed by a resting period of 0.25h.

[0100] Taking this example, multiple instances can be obtained by changing the values ​​of different parameters.

[0101] Table 1 below shows several examples.

[0102] Table 1:

[0103] T(℃) S0 <![CDATA[I1(A)]]> <![CDATA[t1(h)]]> <![CDATA[I2(A)]]> Example 1 25 0 12.1 0.044 5.24 Example 2 25 0 9.06 0.047 6.04 Example 3 25 0 18.1 0.035 6.04 Example 4 25 0 6.66 0.064 4.44 Example 5 25 0 13.3 0.047 4.44 Example 6 25 45％ 12.1 0.044 5.24 Example 7 25 40％ 9.06 0.047 6.04 Example 8 25 40％ 18.1 0.035 6.04 Example 9 25 50％ 6.66 0.064 4.44 Example 10 25 50％ 13.3 0.047 4.44 Example 11 45 0 18 0.029 7.81 Example 12 45 0 12.9 0.033 8.61 Example 13 45 0 25.8 0.024 8.61 Example 14 45 0 10.5 0.041 7.01 Example 15 45 0 21 0.030 7.01 Example 16 45 45％ 18 0.029 7.81 Example 17 45 40％ 12.9 0.033 8.61 Example 18 45 40％ 25.8 0.024 8.61 Example 19 45 50％ 10.5 0.041 7.01 Example 20 45 50％ 21 0.030 7.01

[0104] Table 2 shows several comparisons of charging methods using traditional charging control techniques.

[0105] Table 2:

[0106] T(℃) S0 I, (A) Comparative Example 1 25 0 5.74 Comparative Example 2 25 0 6.30 Comparative Example 3 25 0 6.89 Comparative Example 4 25 0 4.63 Comparative Example 5 25 0 5.05 Comparative Example 6 25 45％ 6.42 Comparative Example 7 25 40％ 6.56 Comparative Example 8 25 40％ 7.89 Comparative Example 9 25 50％ 4.91 Comparative Example 10 25 50％ 6.24 Comparative Example 11 45 0 8.51 Comparative Example 12 45 0 8.96 Comparative Example 13 45 0 9.75 Comparative Example 14 45 0 7.29 Comparative Example 15 45 0 7.93 Comparative Example 16 45 45％ 9.37 Comparative Example 17 45 40％ 9.27 Comparative Example 18 45 40％ 10.92 Comparative Example 19 45 50％ 7.69 Comparative Example 20 45 50％ 9.50

[0107] Table 3 presents the cycle performance of the lithium-ion batteries for each example. The cycle performance includes total charging time, capacity retention after 800 cycles (charged according to the methods of each example), and thickness expansion rate. The thickness expansion rate refers to the increase in the thickness of the lithium-ion battery at full charge relative to its initial thickness.

[0108] Table 3:

[0109] Example Total charging time (h) Capacity retention Thickness expansion rate Example 1 0.849 85.7％ 10.6％ Example 2 0.796 84.1％ 11.1％ Example 3 0.750 83.9％ 11.6％ Example 4 0.993 88.4％ 9.9％ Example 5 0.931 87.4％ 10.3％ Example 6 0.506 95.1％ 9.0％ Example 7 0.531 94.3％ 9.1％ Example 8 0.485 93.9％ 9.2％ Example 9 0.543 96.0％ 8.9％ Example 10 0.480 95.5％ 9.1％ Example 11 0.593 82.3％ 11.9％ Example 12 0.572 81.8％ 12.2％ Example 13 0.540 80.1％ 12.6％ Example 14 0.664 83.6％ 11.4％ Example 15 0.625 82.4％ 11.7％ Example 16 0.363 90.5％ 10.1％ Example 17 0.387 89.9％ 10.6％ Example 18 0.354 89.4％ 11.6％ Example 19 0.379 91.1％ 9.8％ Example 20 0.339 90.8％ 10.1％

[0110] Table 4 shows the cycle performance of lithium-ion batteries for each comparative example. The cycle performance includes total charging time, capacity retention and thickness expansion rate after 800 cycles (charged according to the method of each comparative example).

[0111] Table 4:

[0112] Comparative Example Total charging time (h) Capacity retention Thickness expansion rate Comparative Example 1 0.849 81.1％ 12.6％ Comparative Example 2 0.796 79.4％ 14.8％ Comparative Example 3 0.750 78.7％ 16.3％ Comparative Example 4 0.993 83.8％ 12.1％ Comparative Example 5 0.931 83.0％ 12.4％ Comparative Example 6 0.506 92.2％ 9.7％ Comparative Example 7 0.531 91.6％ 9.9％ Comparative Example 8 0.485 90.6％ 9.6％ Comparative Example 9 0.543 93.3％ 9.5％ Comparative Example 10 0.481 92.8％ 9.6％ Comparative Example 11 0.594 70.4％ 17.6％ Comparative Example 12 0.573 66.3％ 19.3％ Comparative Example 13 0.540 61.9％ 21.8％ Comparative Example 14 0.665 72.9％ 16.3％ Comparative Example 15 0.625 71.5％ 17.1％ Comparative Example 16 0.363 82.7％ 13.2％ Comparative Example 17 0.387 81.4％ 14.8％ Comparative Example 18 0.355 80.1％ 16.2％ Comparative Example 19 0.379 83.1％ 11.9％ Comparative Example 20 0.339 83.0％ 12.3％

[0113] A comparison of Tables 3 and 4 shows that, under the condition of ensuring similar charging time, the battery charging control method provided in this embodiment can achieve a higher capacity retention rate and a smaller thickness expansion rate, which significantly improves the cycle performance of lithium-ion batteries with silicon-based materials in the negative electrode.

[0114] In summary, this embodiment provides a battery charging control method. This method acquires a series of characteristic parameters of the lithium-ion battery, including its rated capacity, the capacity ratio of silicon-based materials in the lithium-ion battery, ambient temperature, capacity value per unit electrode area, and the ratio of the initial charge of the lithium-ion battery to its rated capacity, as well as environmental parameters. Then, based on the battery's characteristic parameters, a constant current is determined for the battery during the second stage of charging. Based on this constant current during the second stage of charging, the constant current and charging duration for the first stage of charging are determined.

[0115] When charging lithium-ion batteries, this method takes into account the battery's inherent characteristics and environmental conditions, rather than simply pre-setting the current based on voltage and the battery's state of charge (SOC) range. This improves charging speed and charging efficiency. Experimental verification shows that, while maintaining similar charging times, the method provided in this application achieves higher capacity retention and lower thickness expansion, significantly improving the cycle performance of lithium-ion batteries with silicon-based negative electrodes. Therefore, the method provided in this application addresses the challenge of ensuring good cycle performance while maintaining efficient charging for lithium-ion batteries with silicon-based negative electrodes.

[0116] Please see Figure 3An embodiment of this application also provides a battery charging control device 10, comprising:

[0117] The acquisition module 11 is used to acquire at least the rated capacity of the lithium-ion battery, the capacity ratio of silicon-based materials in the lithium-ion battery, the ambient temperature, the capacity value corresponding to the unit electrode area, and the ratio of the initial charge of the lithium-ion battery to the rated capacity.

[0118] The processing module 12 is configured to determine the charging current of the lithium-ion battery during the second stage of charging based on the rated capacity, the capacity value, and the ambient temperature when the ratio is less than or equal to a preset ratio; and to determine the charging current of the lithium-ion battery during the first stage of charging based on the charging current during the second stage of charging and a preset current relationship; and to determine the charging time of the lithium-ion battery during the first stage of charging based on the rated capacity, the capacity ratio, and the charging current during the first stage of charging.

[0119] The charging control module 13 is used to perform the first stage charging of the lithium-ion battery according to the charging current and charging time during the first stage charging, and to perform the second stage charging of the lithium-ion battery according to the charging current during the second stage charging, until the charging end condition is met, and then end the charging.

[0120] The processing module 12 is specifically used to determine comparison parameters based on the capacity value and the ambient temperature, and to determine a first parameter and a second parameter based on the comparison parameters and a preset first value; to determine a first limit value based on the first parameter and the rated capacity, and to determine a second limit value based on the second parameter and the rated capacity; to obtain the charging range to which the charging current belongs during the second stage of charging based on the first limit value and the second limit value; and to select any charging current as the charging current during the second stage of charging within the charging range to which the charging current belongs.

[0121] The processing module 12 is specifically used to determine a third limit value based on the preset second value in the preset current relationship and the charging current during the second stage of charging; determine a fourth limit value based on the preset third value in the preset current relationship and the charging current during the second stage of charging; determine the charging range to which the charging current of the lithium-ion battery during the first stage of charging belongs based on the third limit value and the fourth limit value; and select any charging current as the charging current during the first stage of charging within the charging range to which the charging current of the first stage of charging belongs.

[0122] The processing module 12 is specifically used to obtain a preset fourth value and a preset fifth value, and to obtain a coefficient of the capacity ratio; to determine a fifth limit value based on the coefficient of the capacity ratio, the preset fourth value, the rated capacity and the charging current during the first stage of charging; and to determine a sixth limit value based on the coefficient of the capacity ratio, the preset fifth value, the rated capacity and the charging current during the first stage of charging; and to determine the time range to which the charging time of the lithium-ion battery during the first stage of charging belongs based on the fifth limit and the sixth limit, and to select any time within the time range as the charging time of the lithium-ion battery during the first stage of charging.

[0123] The processing module 12 is specifically used to determine the first denominator value based on the capacity ratio coefficient, the preset fourth value and the rated capacity, and to determine the fifth limit value using the charging current of the ion battery during the first stage of charging as the numerator value; and to determine the second denominator value based on the capacity ratio coefficient, the preset fifth value and the rated capacity, and to determine the sixth limit value using the charging current of the ion battery during the first stage of charging as the numerator value.

[0124] The charging current of the lithium-ion battery during the first stage of charging is greater than the charging current of the lithium-ion battery during the second stage of charging; the cutoff current is less than the charging current during the second stage of charging; the capacity ratio is greater than or equal to 0.1 and less than or equal to 0.5; the capacity value is greater than or equal to 1.5 mA per square centimeter and less than or equal to 3.5 mA per square centimeter; the ambient temperature is greater than or equal to 5 degrees Celsius and less than or equal to 50 degrees Celsius.

[0125] The acquisition module 11 is specifically used to acquire the initial charging voltage of the lithium-ion battery; and to determine the ratio of the initial charge of the lithium-ion battery to its rated capacity based on the initial charging voltage, the correspondence between charge and voltage.

[0126] The preset ratio is determined based on this capacity percentage.

[0127] The charging control module 13 is specifically used to control the lithium-ion battery to charge at a constant voltage when the cutoff voltage is reached, until the cutoff current is reached, thus meeting the charging end condition and ending the charging; the charging control module 13 is also used to discharge the lithium-ion battery with a preset current after resting for a first preset time, until the discharge cutoff voltage is reached, and then rest for a second preset time.

[0128] Please see Figure 4 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 to implement the battery charging control method provided in any of the above embodiments.

[0129] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed, cause the computer-executable instructions to be executed by a processor to implement the battery charging control method provided in any of the preceding embodiments.

[0130] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the battery charging control method as provided in any of the preceding embodiments.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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 battery charging control method, characterized in that, include: At least the rated capacity of the lithium-ion battery, the capacity ratio of silicon-based materials in the lithium-ion battery, the ambient temperature, the capacity value corresponding to the unit electrode area, and the ratio of the initial charge of the lithium-ion battery to the rated capacity should be obtained. When the ratio is less than or equal to a preset ratio, a comparison parameter is determined based on the capacity value and the ambient temperature, and a first parameter and a second parameter are determined based on the comparison parameter and a preset first value; a first limit is determined based on the first parameter and the rated capacity, and a second limit is determined based on the second parameter and the rated capacity. Based on the first limit and the second limit, the charging current range during the second stage of charging is obtained; Within the charging range of the charging current during the second stage of charging, any charging current is selected as the charging current during the second stage of charging. Furthermore, based on the relationship between the charging current during the second stage of charging and the preset current, the charging current of the lithium-ion battery during the first stage of charging is determined. And, based on the rated capacity, the capacity ratio and the charging current during the first stage of charging, the charging time of the lithium-ion battery during the first stage of charging is determined. The lithium-ion battery is charged in the first stage based on the charging current and charging time during the first stage of charging, and in the second stage based on the charging current during the second stage of charging, until the charging end condition is met, at which point the charging ends.

2. The method according to claim 1, characterized in that, The step of determining the charging current of the lithium-ion battery during the first stage of charging based on the charging current during the second stage of charging and the preset current relationship includes: The third limit is determined based on the preset second value in the preset current relationship and the charging current during the second stage of charging; The fourth limit is determined based on the preset third value in the preset current relationship and the charging current during the second stage of charging. The charging range of the lithium-ion battery during the first stage of charging is determined based on the third and fourth limits. Within the charging range of the charging current during the first stage of charging, any charging current is selected as the charging current during the first stage of charging.

3. The method according to claim 2, characterized in that, The step of determining the charging duration of the lithium-ion battery during the first stage of charging based on the rated capacity, the capacity percentage, and the charging current during the first stage of charging includes: Obtain the preset fourth value and the preset fifth value, and obtain the coefficient of the capacity ratio; A fifth limit is determined based on the capacity ratio coefficient, the preset fourth value, the rated capacity, and the charging current during the first stage of charging; and a sixth limit is determined based on the capacity ratio coefficient, the preset fifth value, the rated capacity, and the charging current during the first stage of charging. Based on the fifth and sixth limits, the charging time range of the lithium-ion battery during the first stage of charging is determined, and any duration within the range is selected as the charging time of the lithium-ion battery during the first stage of charging.

4. The method according to claim 3, characterized in that, The step of determining the fifth limit value based on the capacity ratio coefficient, the preset fourth value, the rated capacity, and the charging current during the first stage of charging includes: The first denominator value is determined based on the capacity ratio coefficient, the preset fourth value, and the rated capacity. The fifth limit value is determined using the charging current of the ion battery during the first stage of charging as the numerator value. The determination of the sixth limit value based on the capacity ratio coefficient, the preset fifth value, the rated capacity, and the charging current during the first stage of charging includes: The second denominator value is determined based on the capacity ratio coefficient, the preset fifth value, and the rated capacity. The sixth limit value is determined using the charging current of the ion battery during the first stage of charging as the numerator value.

5. The method according to claim 1, characterized in that, The charging current of a lithium-ion battery during the first stage of charging is greater than that during the second stage of charging. The capacity ratio is greater than or equal to 0.1 and less than or equal to 0.5; The capacity value is greater than or equal to 1.5 mA per square centimeter and less than or equal to 3.5 mA per square centimeter; The ambient temperature is greater than or equal to 5 degrees Celsius and less than or equal to 50 degrees Celsius.

6. The method according to claim 1, characterized in that, The ratio of the initial charge capacity of the lithium-ion battery to its rated capacity includes: Obtain the initial charging voltage of the lithium-ion battery; Based on the initial charging voltage and the correspondence between charge and voltage, the proportion of the initial charge to the rated capacity of the lithium-ion battery is determined.

7. The method according to claim 1, characterized in that, The preset ratio is determined based on the capacity ratio.

8. The method according to claim 1, characterized in that, When the charging termination condition is met, ending the charging process includes: When the cutoff voltage is reached, the lithium-ion battery is controlled to be charged at a constant voltage until the cutoff current is reached, at which point the charging end condition is met and the charging ends. The cutoff current is less than the charging current during the second stage of charging. After the charging process ends, the method further includes: After a first preset time of rest, the lithium-ion battery is discharged at a preset current until the discharge cutoff voltage is reached, and then it is rested for a second preset time.

9. A battery charging control device, characterized in that, include: The acquisition module is used to acquire at least the rated capacity of the lithium-ion battery, the capacity ratio of silicon-based materials in the lithium-ion battery, the ambient temperature, the capacity value corresponding to the unit electrode area, and the ratio of the initial charge of the lithium-ion battery to the rated capacity. The processing module is configured to, when the ratio is less than or equal to a preset ratio, determine comparison parameters based on the capacity value and the ambient temperature, and determine a first parameter and a second parameter based on the comparison parameters and a preset first value; determine a first limit based on the first parameter and the rated capacity, and determine a second limit based on the second parameter and the rated capacity; Based on the first limit and the second limit, the charging current range during the second stage of charging is obtained; Within the charging range of the charging current during the second stage of charging, any charging current is selected as the charging current during the second stage of charging. Furthermore, based on the relationship between the charging current during the second stage of charging and the preset current, the charging current of the lithium-ion battery during the first stage of charging is determined. And, based on the rated capacity, the capacity ratio and the charging current during the first stage of charging, the charging time of the lithium-ion battery during the first stage of charging is determined. The charging control module is used to perform the first stage charging of the lithium-ion battery based on the charging current and charging time during the first stage charging, and to perform the second stage charging of the lithium-ion battery based on the charging current during the second stage charging, until the charging end condition is met, and then the charging ends.

10. An electronic device, characterized in that, include: 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 battery charging control method as described in any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions that, when executed, cause the computer to perform the battery charging control method as described in any one of claims 1 to 8.

Images