Battery charging and discharging method, electronic device and storage medium

Abstract

The present application provides a battery charging and discharging method, an electronic device and a storage medium. The method comprises: during each charging and discharging process, determining whether the first capacity ratio of the battery is within a preset interval x; when the first capacity ratio of the battery is within the preset interval x or greater than the preset interval x, charging and discharging the battery with a charging cut-off voltage of bV and a discharging cut-off voltage of aV; when the first capacity ratio of the battery is less than the preset interval x, respectively reducing the charging cut-off voltage of the battery to (b‑d1)V and the discharging cut-off voltage of the battery to (a‑c1)V, and then charging and discharging the battery until the first capacity ratio is greater than the preset interval x. The technical solution of the present application can simultaneously obtain a high discharge capacity of the battery and improve its high temperature performance.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery charging and discharging method, an electronic device, and a storage medium. Background Art

[0002] At present, with the intelligence and multifunctionality of electronic devices, the energy density of lithium-ion batteries needs to be further improved. The development of anode materials for lithium-ion batteries has changed from graphite systems to silicon (Si) systems, which has become a technical trend. Given that the Si system has a higher potential for lithium (Li) than the graphite system. Therefore, in lithium-ion batteries, the voltage platform of the Si system is lower at the end of discharge, and the lower voltage platform will affect the low-temperature performance of lithium-ion batteries. At the same time, during the cyclic charge and discharge process, the polarization will increase, resulting in a part of the polarization capacity loss problem. The current method for this problem is to reduce the polarization of the entire battery cell from the system design on the one hand; on the other hand, it is improved by reducing the cut-off voltage design, but the initial reduction in the cut-off voltage will deteriorate the electrochemical performance of the Si system. Summary of the invention

[0003] In view of this, it is necessary to provide a battery charging and discharging method, an electronic device and a storage medium to improve the performance of the battery.

[0004] An embodiment of the present application provides a battery charging and discharging method, the method comprising: in each charging and discharging process, determining whether a first capacity ratio of the battery is within a preset interval x; when the first capacity ratio of the battery is within the preset interval x or greater than the preset interval x, charging and discharging the battery with a charging cut-off voltage of bV and a discharging cut-off voltage of aV; when the first capacity ratio of the battery is less than the preset interval x, respectively reducing the charging cut-off voltage of the battery to (b-d1)V and the discharging cut-off voltage of the battery to (a-c1)V, and then charging and discharging the battery until the first capacity ratio is greater than the preset interval x.

[0005] According to some embodiments of the present application, 2.5V≤a≤3.4V, 4.0V≤b≤4.6V.

[0006] According to some embodiments of the present application, the first capacity ratio is the ratio of the discharge capacity of the battery during discharge from bV to 3.4V to the discharge capacity of the battery during discharge from bV to aV when the temperature T of the battery is 25°C.

[0007] According to some embodiments of the present application, 80%<x<95%.

[0008] According to some embodiments of the present application, the values ​​of c1 and d1 are related to the temperature T of the battery, and the relationship between c1, d1 and T satisfies: when T<30℃, c1=0, d1=0; when 30℃≤T<40℃, 0.05≤c1≤0.20, 0.01≤d1≤0.20; and when 40℃≤T<55℃, 0.10≤c1≤0.30, 0.05≤d1≤0.30.

[0009] According to some embodiments of the present application, the method also includes: during the continued use of the battery, determining whether the second capacity ratio of the battery is within the preset interval x; when the second capacity ratio of the battery is within the preset interval x or greater than the preset interval x, charging and discharging the battery with a charging cut-off voltage of (b-d1)V and a discharging cut-off voltage of (a-c1)V; when the second capacity ratio of the battery is less than the preset interval x, respectively reducing the charging cut-off voltage of the battery to (b-d1-d2)V and the discharging cut-off voltage of the battery to (a-c1-c2)V, and then charging and discharging the battery until the second capacity ratio is greater than the preset interval x.

[0010] According to some embodiments of the present application, the second capacity ratio is the ratio of the discharge capacity of the battery during discharge from (b-d1)V to (3.4-c1)V to the discharge capacity of the battery during discharge from (b-d1)V to (a-c1)V when the temperature T of the battery is 25°C.

[0011] According to some embodiments of the present application, 0.15≤c2≤0.30, 0.04≤d2≤0.10.

[0012] According to some embodiments of the present application, the method further includes: when the battery meets a cut-off condition, stopping reducing the charging cut-off voltage and the discharging cut-off voltage of the battery, the cut-off condition including: the minimum value of the discharging cut-off voltage reaches 2.00V; or the minimum value of the charging cut-off voltage reaches 3.70V; or the capacity of the battery is reduced to 80% of the rated capacity.

[0013] Another embodiment of the present application provides an electronic device, which includes: a battery and a processor, wherein the processor is used to execute the charging and discharging method as described above to charge and discharge the battery.

[0014] Another embodiment of the present application provides a storage medium on which at least one computer instruction is stored. The computer instruction is loaded by a processor and used to execute the charging and discharging method as described above.

[0015] The embodiment of the present application provides a battery charging and discharging method, which gradually reduces the charging cut-off voltage and the discharging cut-off voltage of the battery by monitoring the temperature and the discharge capacity ratio during the battery charging and discharging process to reach a preset condition. The present application can enable the battery to obtain capacity compensation, and simultaneously reduce the risk of side reactions of the battery at high temperature and high voltage, and solve the problem of polarization risk caused by the low discharge platform of Si system batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of an electronic device according to an embodiment of the present application.

[0017] Figure 2 The figure is a flow chart of a battery charging and discharging method according to an embodiment of the present application.

[0018] Figure 3 A schematic diagram of the discharge capacity obtained by using a graphite system battery charging and discharging method and a silicon system battery charging and discharging method provided in an embodiment of the present application when the battery temperature is 45°C.

[0019] Figure 4 This is a schematic diagram of a discharge curve obtained using the charge and discharge method provided in one embodiment of the present application.

[0020] Main component symbols

[0021] Electronic device 100

[0022] Memory 11

[0023] Processor 12

[0024] Battery 13

[0025] Collection device 14

[0026] The following specific implementation methods will further illustrate the present application in detail in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0028] See also Figure 1 , Figure 1 The electronic device 100 includes, but is not limited to, a memory 11, at least one processor 12, a battery 13, and a collection device 14, and the above components can be connected via a bus or directly.

[0029] It should be noted that Figure 1 The electronic device 100 is merely an example. In other embodiments, the electronic device 100 may include more or fewer components, or have a different component configuration. The electronic device 100 may be a mobile phone, a tablet computer, a digital assistant, a personal computer, or any other suitable consumer rechargeable electronic product.

[0030] In one embodiment, the battery 13 is a rechargeable battery for providing electrical energy to the electronic device 100. For example, the battery 13 may be a lithium-ion battery, a lithium polymer battery, a lithium iron phosphate battery, etc. The battery 13 is logically connected to the processor 12 through a battery management system (Battery Management System, BMS), so that the battery management system can realize functions such as charging and discharging. The battery management system can be connected to a power storage inverter (Power Conversion System, PCS) via CAN or RS485. The battery 13 includes one or more battery cells and an adapter board. In one embodiment, the acquisition device 14 is arranged at the welding position of the pole ear on the adapter board, and is used to measure the temperature of the adapter board during the charging or discharging process of the battery 13. In one embodiment, the acquisition device 14 may be a negative temperature system (Negative Temperature Coefficient, NTC) thermistor.

[0031] In one embodiment, the battery 13 includes three or four cells connected in series and in parallel. The battery 13 can be repeatedly charged in a cyclic and rechargeable manner.

[0032] In this embodiment, the battery 13 includes an anode electrode sheet, a cathode electrode sheet, a separator and an electrolyte. The anode electrode sheet includes an anode current collector and an anode active material layer coated on the anode current collector. The anode active material layer includes silicon (Si) or carbon (C). The form of silicon includes but is not limited to single substance Si, silicon oxide (SiO x ), silicon carbon (Si-C), etc. Carbon (C) includes but is not limited to one or more mixed substances such as graphite, hard carbon, soft carbon, etc. In one embodiment, the ratio of silicon to carbon in the anode active material layer is 5% to 80%. The cathode active material in the cathode electrode includes, but is not limited to, lithium cobalt oxide (LiCoO2), lithium iron phosphate (LiFePO4), lithium nickel cobalt manganese oxide (LiNi x Co y Mn 1-x-y O2), lithium nickel cobalt aluminum oxide (LiNi x Co y Al 1-x-yO2)(0≤x, y≤1) and one or more mixed substances thereof.

[0033] See also Figure 2 , Figure 2 This is a flow chart of a battery charging and discharging method according to an embodiment of the present application. The battery charging and discharging method is applied to a battery of an electronic device. The battery charging and discharging method comprises the following steps:

[0034] Step S20: During each charge and discharge process, determining whether the first capacity ratio of the battery is within a preset interval x.

[0035] In order to solve the problem of low anode discharge voltage platform and polarization of silicon-based batteries, the embodiment of the present application can adjust the charge and discharge interval of the battery according to the capacity ratio of the battery during the charging process or the discharging process, so as to maintain the battery swelling while utilizing the capacity of the silicon-based battery.

[0036] Balanced with performance.

[0037] During each charge and discharge process, it is first determined whether the first capacity ratio of the battery is within a preset interval x. If the first capacity ratio is within or greater than the preset interval x, step S21 is executed; if the first capacity ratio is less than the preset interval x, step S22 is executed.

[0038] In the embodiment provided in the present application, the charge and discharge interval of the battery at the time of leaving the factory is (aV~bV), that is, the discharge cut-off voltage of the battery is aV, and the charge cut-off voltage is bV. The range of a is 2.5≤a≤3.4, and the range of b is 4.0≤b≤4.6.

[0039] In one embodiment, the charging and discharging voltage range of the battery is (3.2V-4.45V).

[0040] In the embodiment provided in the present application, the first capacity ratio x is the ratio of the discharge capacity of the battery during discharge from bV to 3.4V to the discharge capacity of the battery during discharge from bV to aV when the temperature T of the battery is 25°C. In this implementation, the discharge capacity of the battery during discharge from bV to 3.4V and the discharge capacity of the battery during discharge from bV to aV can be calculated by the fuel gauge.

[0041] Step S21: when the first capacity ratio of the battery is within the preset interval x or greater than the preset interval x, the battery is charged and discharged with a charge cut-off voltage of bV and a discharge cut-off voltage of aV.

[0042] In the embodiment provided in the present application, if the first capacity ratio of the battery is within or greater than the preset interval x, there is no need to change the charge and discharge interval of the battery, that is, there is no need to change the charge cut-off voltage and / or the discharge cut-off voltage, that is, the battery is charged and discharged with the initial charge cut-off voltage bV and the discharge cut-off voltage aV.

[0043] Step S22: When the first capacity ratio of the battery is less than the preset interval x, the charging cut-off voltage of the battery is reduced to (b-d1)V and the discharging cut-off voltage of the battery is reduced to (a-c1)V, and then the battery is charged and discharged until the first capacity ratio is greater than the preset interval x.

[0044] In the embodiment provided in the present application, if the first capacity ratio of the battery is less than the preset interval x, the charge and discharge interval of the battery needs to be changed. Specifically, the charge cut-off voltage of the battery is reduced to (b-d1)V and the discharge cut-off voltage of the battery is reduced to (a-c1)V, and the battery is charged and discharged using the reduced charge cut-off voltage and discharge cut-off voltage until the first capacity ratio is greater than the preset interval x, that is, the first capacity ratio of the battery needs to be maintained greater than x. In some embodiments, 80%<x<95%.

[0045] It should be noted that the values ​​of c1 and d1 are related to the temperature T of the battery (which may refer to the ambient temperature), and the relationship between c1, d1 and T satisfies: when T<30℃, c1=0, d1=0; when 30℃≤T<40℃, 0.05≤c1≤0.20, 0.01≤d1≤0.20; and when T≥40℃, 0.10≤c1≤0.30, 0.05≤d1≤0.30.

[0046] In some other embodiments, when 40°C≤T<55°C, 0.1≤c1≤0.50, 0.05≤d1≤0.50; and when T≥55°C, charging of the battery is prohibited.

[0047] In one embodiment, if the temperature T of the battery is less than 30°C, the charge and discharge interval of the battery is not adjusted, that is, c1=0, d1=0, and the charge and discharge interval of the battery is kept consistent with the charge and discharge interval (aV~bV) at the time of leaving the factory. The value range of a is 2.5≤a≤3.4, the value range of b is 4.0≤b≤4.6, and the capacity of the battery is maintained at C. It should be noted that the capacity of the battery can be the charging capacity of the battery or the discharging capacity of the battery.

[0048] In one embodiment, if the battery temperature T is greater than or equal to 30° C. and less than 40° C., the battery charge cut-off voltage and the battery discharge cut-off voltage need to be reduced. At this time, the range of c1 is 0.05≤c1≤0.20, and the range of d1 is 0.05≤d1≤0.20.

[0049] In one embodiment, if the battery temperature T is greater than or equal to 40° C. and less than 55° C., the battery charge cut-off voltage and the battery discharge cut-off voltage also need to be reduced. At this time, the range of c1 is 0.10≤c1≤0.30, and the range of d1 is 0.05≤d1≤0.30.

[0050] It should be noted that the temperature of the battery 13 can be the temperature of the battery cell or the temperature of the adapter board in the battery. When the temperature T of the battery changes, it is necessary to change the charge and discharge interval of the battery, and ensure that the capacity C of the battery in the changed charge and discharge interval remains unchanged, that is, the charge capacity or discharge capacity C of the battery between the reduced charge cut-off voltage (b-d1)V and the discharge cut-off voltage (a-c1)V is equal to the charge capacity or discharge capacity C between the initial charge cut-off voltage (b-d1)V and the discharge cut-off voltage (a-c1)V.

[0051] It should be noted that the charging cut-off voltage describes the full charging cut-off voltage when the battery 13 reaches a fully charged state. The fully charged state describes the battery system reaching the charging limit voltage and the preset charging cut-off current during charging. The charging limit voltage and the charging cut-off current may be fixed voltages and currents related to the battery system, or voltages and currents set according to customer needs.

[0052] Step S23: during the continued use of the battery, determining whether the second capacity ratio of the battery is within the preset interval x.

[0053] In this embodiment, during the use process after reducing the charge cut-off voltage and discharge cut-off voltage of the battery, the capacity ratio of the battery will change. It is necessary to determine whether the second capacity ratio of the battery is within the preset interval x. If the second capacity ratio is within the preset interval or greater than the preset interval, step S24 is executed; if the second capacity ratio is less than the preset interval, step S25 is executed. The second capacity ratio is the ratio of the discharge capacity of the battery during the discharge from (b-d1)V to (3.4-c1)V to the discharge capacity of the battery during the discharge from (b-d1)V to (a-c1)V when the temperature T of the battery is 25°C.

[0054] Step S24: When the second capacity ratio of the battery is within the preset interval x or greater than the preset interval x, the battery is charged and discharged with a charging cut-off voltage of (b-d1)V and a discharging cut-off voltage of (a-c1)V.

[0055] In the embodiment provided in the present application, if the second capacity ratio of the battery is within the preset interval x or greater than the preset interval x, there is no need to change the charge and discharge interval of the battery, that is, there is no need to change the charge cut-off voltage and / or the discharge cut-off voltage. The battery is charged and discharged with a charge cut-off voltage of (b-d1)V and a discharge cut-off voltage of (a-c1)V.

[0056] Step S25: When the second capacity ratio of the battery is less than the preset interval x, the charging cut-off voltage of the battery is reduced to (b-d1-d2)V and the discharging cut-off voltage of the battery is reduced to (a-c1-c2)V, and then the battery is charged and discharged until the second capacity ratio is greater than the preset interval x.

[0057] In the embodiment provided in the present application, if the second capacity ratio of the battery is less than the preset interval x, the charge and discharge interval of the battery needs to be changed. Specifically, the charge cut-off voltage of the battery is reduced to (b-d1-d2)V and the discharge cut-off voltage of the battery is reduced to (a-c1-c2)V, and the battery is charged and discharged using the reduced charge cut-off voltage and discharge cut-off voltage until the second capacity ratio is greater than the preset interval x, that is, the second capacity ratio of the battery needs to be maintained greater than the preset interval x. In some embodiments, 80%<x<95%. Among them, 0.15≤c2≤0.30, 0.04≤d2≤0.10.

[0058] Step S26: If the battery meets the cut-off condition, stop reducing the charge cut-off voltage and the discharge cut-off voltage of the battery.

[0059] It is understandable that the charging cut-off voltage and the discharging cut-off voltage of the battery 13 are not always reduced during the continuous use of the battery 13. If the battery 13 meets the cut-off condition, the charging cut-off voltage and the discharging cut-off voltage of the battery 13 are stopped from being reduced.

[0060] Specifically, the cut-off conditions include: the minimum value of the discharge cut-off voltage reaches 2.00V; or the minimum value of the charge cut-off voltage reaches 3.70V; or the capacity of the battery is reduced to 80% of the rated capacity. As long as one of the cut-off conditions is met, the charge cut-off voltage and the discharge cut-off voltage of the battery 13 will no longer be reduced.

[0061] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the battery charging and discharging method of the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0062] When preparing the battery, the cathode electrode sheet, the separator and the anode electrode sheet are sequentially stacked and wound or stacked according to production requirements. The separator is used to separate the cathode electrode sheet and the anode electrode sheet. The wound electrode assembly is wrapped with an aluminum plastic film on the outside, and then the electrolyte is injected. After vacuum baking and formation, the finished battery cell monomer can be obtained. After several battery cell monomers are connected in series and parallel, the battery can be obtained.

[0063] In one embodiment, under different battery temperature conditions, the charge and discharge range of the graphite system battery is shown in Table 1. When the battery temperature T < 30 ° C, the charge and discharge range of the graphite system battery is 3.20V ~ 4.45V; when the battery temperature satisfies 30 ° C ≤ T < 40 ° C, the charge and discharge range of the graphite system battery is 3.20V ~ 4.43V; when the battery temperature satisfies 40 ° C ≤ T < 55 ° C, the charge and discharge range of the graphite system battery is 3.20V ~ 4.15V; when the temperature is T ≥ 55 ° C, charging of the battery is prohibited.

[0064] Table 1 Relationship between charge and discharge voltage range and temperature of graphite system battery

[0065] Battery temperature T(℃) Charge and discharge voltage range (V) T＜30℃ 3.20V~4.45V 30℃≤T＜40℃ 3.20V~4.43V 40℃≤T＜55℃ 3.20V~4.15V T≥55℃ Charging is prohibited

[0066] The charge and discharge voltage range design of the graphite system battery and the adjustment of the charge and discharge voltage range during the cycle use are shown in Table 2. When the battery temperature T<30℃, the charge and discharge voltage range is kept unchanged throughout the life cycle; when the battery temperature satisfies 30℃≤T<40℃, the charge and discharge voltage range of the battery remains unchanged before the graphite system battery undergoes 200 charge and discharge cycles; after 200 charge and discharge cycles, the voltage is reduced once, and after a certain number of cycles (greater than 200 times), the charge cut-off voltage is reduced to (b-0.05)V, and the discharge voltage is reduced to (b-0.05)V. The charge cut-off voltage remains unchanged; when the temperature of the battery satisfies 40°C≤T<55°C, before the graphite system battery undergoes 100 charge and discharge cycles, the charge and discharge voltage range of the battery remains unchanged; a voltage reduction is performed between 100 and 200 charge and discharge cycles, the charge cut-off voltage is reduced to (b-0.03)V, and the discharge cut-off voltage remains unchanged; a voltage reduction is performed again between 100 and 200 charge and discharge cycles, the charge cut-off voltage is reduced to (b-0.06)V, and the discharge cut-off voltage remains unchanged; in this way, the charge cut-off voltage reduction operation is performed according to the number of charge and discharge cycles;

[0067] Table 2 Adjustment of the charging and discharging voltage range of graphite system batteries during use

[0068]

[0069] According to the design of the charge and discharge voltage range adjustment of the graphite system battery in use in Table 2, under different temperature conditions, only the charge cut-off voltage of the graphite system battery is adjusted, and the discharge cut-off voltage is not changed. For example, when the battery temperature T is less than 30°C, the charge and discharge range of the lithium cobalt oxide / graphite system is 3.2V~4.45V, and the discharge capacity of the battery is defined as 100% at this time; when the battery temperature meets 30°C≤T<40°C, the charge and discharge range of battery 13 will be reduced to 3.2V~4.43V, and the discharge capacity of the battery is 97%, sacrificing only 3% of the capacity; when the battery temperature meets 40°C≤T<55°C, the charge and discharge range of battery 13 will be reduced to 3.2V~4.15V, and the discharge capacity of the battery is 91%, sacrificing only 9% of the capacity; when the temperature is T≥55°C, charging of the battery is prohibited. It can be seen that in order to reduce the risk of side reactions of graphite system batteries at high temperature and high voltage, the charge cut-off voltage of the graphite system batteries is lowered, sacrificing the capacity of the graphite system batteries.

[0070] In another embodiment, for the charge and discharge voltage range design of the Si-based battery, the charge cut-off voltage and the discharge cut-off voltage need to be adjusted under different battery temperature conditions. As shown in Example 1 in Table 3, when the battery temperature T is less than 30°C, the charge and discharge range of the lithium cobalt oxide / silicon system battery is 3.2V~4.45V, and the discharge capacity of the battery is defined as 100% at this time; when the battery temperature satisfies 30°C≤T<40°C, the charge and discharge range of battery 13 will be reduced to 3.1V~4.43V, and the discharge capacity of the battery will remain at 100% without sacrificing capacity; when the battery temperature satisfies 40°C≤T<55°C, the charge and discharge range of battery 13 will be reduced to 2.8V~4.15V, and the discharge capacity of the battery is 97%, sacrificing only 3% of the capacity; when the temperature is T≥55°C, charging of the battery is prohibited. Figure 3 In the figure, the discharge capacity curve of the battery after 300 charge and discharge cycles at 45°C using the method provided in Example 1 is compared with the discharge capacity curve of the battery after 300 charge and discharge cycles using the charge and discharge method used for the graphite system battery. It can be seen that Example 1 can achieve about 6% capacity compensation for the battery by reducing the discharge cut-off voltage. The method provided in Example 1 of the present application can achieve capacity compensation for the battery by reducing the discharge cut-off voltage, and simultaneously reduces the risk of side reactions under high temperature and high voltage, solving the problem of polarization risk caused by the low discharge platform of the Si system battery.

[0071] As shown in Example 2 in Table 3, when the battery temperature T is less than 30°C, the charge and discharge range of the lithium cobalt oxide / silicon system battery is 3.2V to 4.45V, and the discharge capacity of the battery is defined as 100% at this time; when the battery temperature satisfies 30°C ≤ T < 40°C, the charge and discharge range of battery 13 will be reduced to 3.00V to 4.40V, and the discharge capacity of the battery will remain at 100% without sacrificing capacity; when the battery temperature satisfies 40°C ≤ T < 55°C, the charge and discharge range of battery 13 will be reduced to 2.75V to 4.10V, and the discharge capacity of the battery will be 96%, sacrificing only 4% of the capacity; when the temperature is T ≥ 55°C, charging of the battery is prohibited. Figure 3 In the figure, the discharge capacity curve of the battery after 300 charge and discharge cycles at 45°C using the method provided in Example 2 is compared with the discharge capacity curve of the battery after 300 charge and discharge cycles using the method provided in Example 1. It can be seen that Example 2 further reduces the discharge cut-off voltage and the full charge cut-off voltage, and the capacity difference with Example 1 is 1%, and there is a more obvious improvement in the later stage of the cycle, thereby reducing the side reactions at high temperature. By further reducing the discharge cut-off voltage and the charge cut-off voltage, the risk of side reactions at high temperature and high voltage is further reduced while ensuring the capacity compensation conditions similar to those of Example 1.

[0072] Table 3 Adjustment of the charge and discharge voltage range of Example 1-2 corresponding to the Si system battery

[0073]

[0074]

[0075] Considering that the discharge voltage platform of Si system batteries is low, there are factors affecting polarization. The embodiment of the present application simultaneously reduces the charge cut-off voltage and the discharge cut-off voltage. On the one hand, it satisfies the problem of capacity sacrifice caused by reducing the charge cut-off voltage, and on the other hand, it reduces the problem of low discharge capacity at low voltage caused by polarization. Specifically, the charge and discharge interval of the Si system battery is initially defined as 3.20V to 4.45V. After 235 charge and discharge cycles, the discharge capacity of the battery when the voltage is discharged from 4.45V to 3.40V is detected and calculated by the fuel gauge. When the first capacity ratio of the discharge capacity of the battery when the voltage is discharged from 4.45V to 3.20V is ≤90%, the first charge and discharge voltage interval adjustment is started, that is, the discharge cut-off voltage is reduced to 3.0V, and the charge cut-off voltage is reduced to 4.30V simultaneously. After the voltage is reduced, the first capacity ratio of the discharge capacity of the battery when the voltage is discharged from 4.3V to 3.20V and the discharge capacity of the battery when the voltage is discharged from 4.30V to 3.00V is greater than 90%. After the first adjustment of the charge and discharge voltage range of the battery 13, after using the battery for 570 charge and discharge cycles according to the adjusted charge and discharge voltage range, it is detected that the second capacity ratio is <90%, and the second charge and discharge voltage range adjustment is initiated, that is, the discharge cut-off voltage is lowered to 2.75V, and the charge cut-off voltage is simultaneously lowered to 4.20V. The second capacity ratio of the discharge capacity of the battery when the voltage is discharged from 4.20V to 3.00V after the voltage reduction and the discharge capacity of the battery when the voltage is discharged from 4.20V to 2.75V is greater than 90%. According to this logic, when the discharge cut-off voltage of the battery 13 reaches 2.00V, or the charge cut-off voltage reaches 3.70V, or the capacity of the battery is reduced to 80% of the rated capacity, the charge cut-off voltage and discharge cut-off voltage of the battery are stopped from being reduced. Figure 4 As shown, the battery can obtain capacity compensation by gradually reducing the charge cut-off voltage and the discharge cut-off voltage of the battery, and the risk of side reactions of the battery at high temperature and high voltage is also reduced simultaneously.

[0076] The embodiment provided in the present application can gradually reduce the charge cut-off voltage and the discharge cut-off voltage of the battery by monitoring the temperature during the battery charge and discharge process and when the discharge capacity ratio reaches a preset condition, so that the battery capacity can be compensated and the performance balance can be ensured.

[0077] Please continue reading Figure 1 In this embodiment, the memory 11 may be an internal memory of the electronic device 100, that is, a memory built into the electronic device 100. In other embodiments, the memory 11 may also be an external memory of the electronic device 100, that is, a memory externally connected to the electronic device 100.

[0078] In some embodiments, the memory 11 is used to store program codes and various data, and to achieve high-speed and automatic access to programs or data during the operation of the electronic device 100 .

[0079] The memory 11 may include a random access memory and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0080] In one embodiment, the processor 12 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any other conventional processor, etc.

[0081] If the program code and various data in the memory 11 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, such as implementing the steps in the battery charging and discharging method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), etc.

[0082] It is understandable that the module division described above is a logical function division, and there may be other division methods in actual implementation. In addition, the functional modules in each embodiment of the present application may be integrated in the same processing unit, or each module may exist physically separately, or two or more modules may be integrated in the same unit. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application has been described in detail with reference to the preferred embodiments, a person of ordinary skill in the art should understand that the technical solution of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A battery charging and discharging method, characterized in that: The method comprises: During each charge and discharge process, determining whether a first capacity ratio of the battery is within a preset interval x, wherein the first capacity ratio is a ratio of a discharge capacity of the battery during discharge from bV to 3.4V to a discharge capacity of the battery during discharge from bV to aV when the temperature T of the battery is 25° C.; When the first capacity ratio of the battery is within the preset interval x or greater than the preset interval x, the battery is charged and discharged with a charge cut-off voltage of bV and a discharge cut-off voltage of aV, 2.5V≤a≤3.4V, 4.0V≤b≤4.6V; When the first capacity ratio of the battery is less than the preset interval x, the battery is charged and discharged after the charge cut-off voltage of the battery is reduced to (b-d1)V and the discharge cut-off voltage of the battery is reduced to (a-c1)V respectively until the first capacity ratio is greater than the preset interval x, and the values ​​of c1 and d1 are related to the temperature T of the battery.

2. The charge and discharge method according to claim 1, characterized in that: 80％＜x＜95％。 3. The charge and discharge method according to any one of claims 1 to 2, characterized in that: The relationship between the values ​​of c1 and d1 and the temperature T of the battery satisfies: When T<30℃, c1=0, d1=0; When 30℃≤T<40℃, 0.05≤c1≤0.20, 0.01≤d1≤0.20; and When 40℃≤T<55℃, 0.10≤c1≤0.30, 0.05≤d1≤0.

30.

4. The charge and discharge method according to claim 3, characterized in that: The method further comprises: During continued use of the battery, determining whether the second capacity ratio of the battery is within the preset interval x; When the second capacity ratio of the battery is within the preset interval x or greater than the preset interval x, the battery is charged and discharged with a charge cut-off voltage of (b-d1)V and a discharge cut-off voltage of (a-c1)V; When the second capacity ratio of the battery is less than the preset interval x, the charging cut-off voltage of the battery is reduced to (b-d1-d2)V and the discharging cut-off voltage of the battery is reduced to (a-c1-c2)V, and then the battery is charged and discharged until the second capacity ratio is greater than the preset interval x.

5. The charge and discharge method according to claim 4, characterized in that: The second capacity ratio is the ratio of the discharge capacity of the battery during discharge from (b-d1)V to (3.4-c1)V to the discharge capacity of the battery during discharge from (b-d1)V to (a-c1)V when the temperature T of the battery is 25°C.

6. The charge and discharge method according to claim 4, characterized in that: 0.15≤c2≤0.30, 0.04≤d2≤0.

10.

7. The charge and discharge method according to claim 4, characterized in that: The method further includes: when the battery meets a cut-off condition, stopping reducing a charge cut-off voltage and a discharge cut-off voltage of the battery, wherein the cut-off condition includes: The minimum value of the discharge cut-off voltage reaches 2.00V; or The minimum value of the charging cut-off voltage reaches 3.70V; or The capacity of the battery dropped to 80% of the rated capacity.

8. An electronic device, characterized in that: The electronic device comprises: Batteries; and A processor, configured to execute the charging and discharging method according to any one of claims 1 to 7 to charge and discharge the battery.

9. A storage medium having at least one computer instruction stored thereon, characterized in that: The instructions are loaded by a processor and used to execute the charging and discharging method according to any one of claims 1 to 7.

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