Charging control method and device and electronic equipment

Abstract

The invention provides a charging control method and device and electronic equipment, and is applied to the technical field of electronics. The charging control method is applied to the electronic equipment, the electronic equipment and a charger form a charging system, the electronic equipment comprises a charging circuit, and the charging circuit is used for charging a battery of the electronic equipment. The charging control method comprises the following steps: in an under-voltage state of a battery, controlling a charging circuit to continuously output a first current to the battery from a first moment; in the under-voltage state of the battery, the charging circuit is controlled to continuously output a second current to the battery from a second moment; the second moment is after the first moment, and the second current is greater than the first current. In the under-voltage state, the battery is charged with the higher second current from the second moment, so that the charging speed can be improved, and the charging duration can be shortened.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic technology, and in particular to a charging control method, device and electronic equipment. Background Art

[0002] Lithium-ion batteries are widely used in electronic products, such as mobile phones, laptops, bracelets, watches, smart robots and other electronic devices.

[0003] Usually, if the battery is exhausted and not recharged in time, the battery voltage will gradually decrease and enter an undervoltage state, and the battery voltage may even drop below 1.5V. In order to protect the battery, the charging management chip usually strictly limits the charging rate (= current / rated capacity) when charging again. At present, when the battery is in an undervoltage state, a constant current low current charging strategy is usually implemented, such as using 0.01C to charge to 2.6V. When the battery voltage reaches 2.6V, the normal fast charging process is enabled to continue charging.

[0004] In this way, since constant current and low current charging are used in the under-voltage state, the charging speed is very slow, which will cause the entire charging cycle to be very long, seriously affecting the user experience. Summary of the invention

[0005] The embodiments of the present application provide a charging control method, device and electronic device, which can increase the charging speed and reduce the charging time.

[0006] In the first aspect, a charging control method is provided, which is applied to an electronic device, wherein the electronic device and a charger form a charging system, and the electronic device includes a charging circuit, and the charging circuit is used to charge the battery of the electronic device. The method comprises the following steps: in the undervoltage state of the battery, the charging circuit is controlled to continuously output a first current to the battery from a first moment; in the undervoltage state of the battery, the charging circuit is controlled to continuously output a second current to the battery from a second moment; the second moment is located after the first moment, and the second current is greater than the first current. Different from the current charging strategy, the charging control method provided in the embodiment of the present application uses a second current greater than the first current to perform constant current charging on the battery after the battery is in an undervoltage state. Therefore, compared with the current charging strategy, when the same charging capacity is completed, the charging control method provided in the embodiment of the present application can increase the charging speed and reduce the charging time.

[0007] In a possible implementation, the method further includes: in the undervoltage state of the battery, controlling the charging circuit to continuously output a third voltage to the battery from a third moment. Usually, at the third moment, when the voltage of the battery reaches the third voltage U0, the battery can be charged by a constant voltage charging method at the third voltage U0, so that since a section of constant voltage charging of the battery is added in the undervoltage state, the polarization voltage of the battery can be eliminated, and the side reaction of the interface between the lithium-ion battery electrode and the electrolyte is effectively reduced, thereby reducing the impact on the battery life.

[0008] In a possible implementation, the method further includes: at the second moment, it is determined that the voltage of the battery is the second voltage, then the charging circuit is controlled to output a second current to the battery, the second voltage is greater than the first voltage, and the first voltage is the voltage of the battery at the first moment. Specifically, the second moment may be after the battery is charged to the second voltage U01 with the first current I0 at the first moment. In the above example, the first voltage may be less than or equal to the second voltage U01, and the second voltage U01 is less than or equal to the third voltage U0. Of course, the first voltage is not fixed. When the battery enters the undervoltage state, as long as the battery is not charged by the charger, it can be considered that the battery voltage will continue to decrease; when the battery voltage is the second voltage U01, the second moment is entered, and the battery is charged with a constant current through the larger second current I01.

[0009] In a possible implementation, the difference between the second voltage and the first voltage is less than or equal to 200mv. In order to reduce the charging time, the constant current charging time of the battery with the first current needs to be as short as possible, and the difference between the second voltage and the first voltage needs to be as small as possible. For example, the battery can be charged with the first current, and when the battery voltage is increased by 200mv, the battery is started to be charged with the second current at a constant current. Preferably, the battery can be charged with the second current at a constant current after the battery voltage is increased by 50mv.

[0010] In a possible implementation, the method further includes: at a third moment, determining that the voltage of the battery is a third voltage, controlling the charging circuit to output the third voltage to the battery, the third voltage being greater than the second voltage, and the second voltage being the voltage of the battery at the second moment.

[0011] In a possible implementation, the method further includes: starting from the third moment, when the current output by the charging circuit to the battery is equal to the first current, normal charging is started. As the time of constant voltage charging of the battery by the third current continues, the charging current gradually decreases until the charging current reaches the initial first current I0 and then exits the undervoltage state, and normal charging is started to fast charge the battery in the normal voltage range.

[0012] In a possible implementation, the method further includes: obtaining characteristic parameters of the battery, the characteristic parameters including at least one or more of the following: temperature, number of cycles; obtaining a first current according to the characteristic parameters and a parameter table, the parameter table containing a correspondence between the characteristic parameters and the first current.

[0013] In a possible implementation, the method further includes: obtaining characteristic parameters of the battery, the characteristic parameters including at least one or more of the following: temperature, number of cycles; obtaining the second current according to the characteristic parameters and a parameter table, the parameter table containing a correspondence between the characteristic parameters and the second current.

[0014] In a possible implementation, the method further includes: obtaining characteristic parameters of the battery, the characteristic parameters including at least one or more of the following: temperature, number of cycles; obtaining the second voltage according to the characteristic parameters and a parameter table, the parameter table containing a correspondence between the characteristic parameters and the second current.

[0015] In a possible implementation, the method further includes: obtaining characteristic parameters of the battery, the characteristic parameters including at least one or more of the following: temperature, number of cycles; obtaining a third voltage according to the characteristic parameters and a parameter table, the parameter table containing a correspondence between the characteristic parameters and the second current.

[0016] Generally, in the undervoltage state of the entire battery, it must be ensured that there is no lithium dendrite precipitation at the negative electrode of the battery, so as to avoid affecting the battery life; therefore, the first current I 0, the second current I 01, the second voltage U01 and the third voltage U0 can adopt fixed values; of course, in order to further optimize the service life of the battery, the first current I 0, the second current I 01, the second voltage U01 and the third voltage U0 can also be adjusted dynamically in real time. Specifically, it can be based on the characteristic parameters of the battery, such as temperature, number of cycles, etc., and obtain one or more of the first current I 0, the second current I 01, the second voltage U01 and the third voltage U0 corresponding to different temperatures and / or number of cycles by looking up the parameter table. Of course, the dynamically adjusted first current I 0, the second current I 01, the second voltage U01 and the third voltage U0 can be obtained based on the calibration of the charging strategy for the undervoltage state of the battery throughout its life cycle, or obtained through machine learning training.

[0017] In a possible implementation, the method further includes: starting timing from the first moment, and when it is determined that the cumulative duration exceeds the time threshold, controlling the charging circuit to stop charging. The charging control method adopted in this scheme needs to ensure the safety of the battery while increasing the first current I 0 to the second current I 01 when performing constant current charging on the battery. Therefore, the battery health status diagnosis can also be performed after charging starts in the undervoltage state. Specifically, timing can be started from the first moment, and when it is determined that the cumulative duration exceeds the time threshold, the charging circuit is controlled to stop charging. Since the charging time in the undervoltage state will be significantly longer than that of a normal battery when there is an internal short circuit in the battery, the time threshold of the cumulative charging time can be set as a judgment threshold according to the difference in the charging time in the undervoltage state between the battery internal short circuit sample and the normal battery sample. Once the cumulative charging time exceeds the time threshold, the charging is controlled to stop to avoid causing battery safety problems.

[0018] In a possible implementation, in the undervoltage state, the voltage of the battery is less than or equal to 3.0 V. For different battery models, in the undervoltage state, the voltage of the battery may also be less than or equal to 2.6 V or 2.8 V.

[0019] In a possible implementation, in the undervoltage state, the battery power is less than or equal to a predetermined power level, which may be a power level displayed by the electronic device as 0% or close to 0%.

[0020] In a second aspect, a charging control device is provided, which is applied to an electronic device, and may be the electronic device itself or a chip or chip system provided in the electronic device. The charging control device is used to execute the charging control method as described in the first aspect and possible implementations thereof.

[0021] In a third aspect, a chip is provided, comprising the charging control device according to the second aspect.

[0022] In a fourth aspect, an electronic device is provided, comprising a battery and a charging circuit, wherein the charging circuit is connected to the battery; and further comprising: a charging control device as described in the second aspect, wherein the charging control device is connected to the charging circuit.

[0023] Among them, the technical problems solved by the second to fourth aspects and their possible implementation methods and the technical effects achieved can be referred to the description in the first aspect and its possible implementation methods, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a charging system provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0026] Figure 3 A schematic diagram of the structure of an interface provided in an embodiment of the present application;

[0027] Figure 4 A schematic diagram of the structure of an electronic device provided in another embodiment of the present application;

[0028] Figure 5 A schematic flow chart of a charging control method provided in an embodiment of the present application;

[0029] Figure 6 A schematic diagram of a curve of charging voltage and charging rate provided in an embodiment of the present application;

[0030] Figure 7 A schematic flow chart of a charging control method provided in another embodiment of the present application;

[0031] Figure 8 A schematic diagram of a curve of a positive electrode voltage and a negative electrode voltage of a battery provided in an embodiment of the present application;

[0032] Fig. 9 A schematic flow chart of a charging control method provided for another embodiment of the present application;

[0033] Fig.10 A schematic diagram of a charging voltage change process provided in an embodiment of the present application;

[0034] Fig.11 A schematic diagram of a cycle capacity change process provided in an embodiment of the present application;

[0035] Fig.12 A schematic flow chart of a charging control method provided for another embodiment of the present application;

[0036] Fig.13 A schematic diagram of a charging voltage and a charging current variation process of a charging control method provided in yet another embodiment of the present application;

[0037] Fig.14 A schematic diagram of a cycle capacity change process provided for another embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions in some embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0039] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "multiple" means two or more. Unless otherwise clearly specified and limited, the term "connected" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium.

[0040] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0041] The charging control method provided in the embodiment of the present application can be applied to electronic devices such as mobile phones, tablet computers, laptops, ultra-mobile personal computers (UMPCs), handheld computers, netbooks, personal digital assistants (PDAs), wearable electronic devices, and virtual reality devices.

[0042] Combination Figure 1 As shown, an embodiment of the present application provides a charging system consisting of an electronic device 10 and a charger 20. Generally, the charger 20 includes a housing, a power conversion circuit installed in the housing, wherein the input side of the power conversion circuit is usually connected to the mains (for example, it can be a 220V AC mains) through a plug provided on the housing, and the output side of the power conversion circuit is connected to the electronic device 10 through a plug 200. In addition, the power conversion circuit can usually be soldered on a printed circuit board PCB in the housing. In some examples, the charger 20 is also called a power adapter.

[0043] For example, Figure 2 A schematic structural diagram of an electronic device 10 is shown.

[0044] like Figure 2As shown, the electronic device 10 may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging circuit 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc.

[0045] It is to be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the electronic device 10. In other embodiments of the present application, the electronic device 10 may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0046] Processor 110 may include one or more processing units.

[0047] For example, the processor 110 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors.

[0048] In some embodiments, the electronic device 10 may also include one or more processors 110. The processor 110 may be the nerve center and command center of the electronic device 10. The processor 110 may generate an operation control signal according to the instruction operation code and the timing signal to complete the control of fetching and executing instructions.

[0049] The processor 110 may also be provided with a memory for storing instructions and data.

[0050] In some embodiments, the memory in the processor 110 is a cache memory. The memory can store instructions or data that the processor 110 has just used or cyclically used. If the processor 110 needs to use the instruction or data again, it can be directly called from the memory. This avoids repeated access, reduces the waiting time of the processor 110, and thus improves the efficiency of the electronic device 10 system.

[0051] In some embodiments, the processor 110 may include one or more interfaces. The interface may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0052] The USB interface 130 is an interface that complies with USB standard specifications, and specifically can be a Mini USB interface, a MicroUSB interface, a USB Type C interface, etc. The USB interface 130 can be used to connect the power adapter 20 to charge the electronic device 10, can also be used to transmit data between the electronic device 10 and peripheral devices, and can also be used to connect headphones to play audio through the headphones.

[0053] It is understandable that the interface connection relationship between the modules illustrated in the embodiment of the present invention is only a schematic illustration and does not constitute a structural limitation on the electronic device 10. In other embodiments of the present application, the electronic device 10 may also adopt different interface connection methods in the above embodiments, or a combination of multiple interface connection methods.

[0054] The charging circuit 140 is used to receive a charging input from a charger. While charging the battery 142 , the charging circuit 140 can also supply power to the electronic device 10 through the power management module 141 .

[0055] In some embodiments, the charging circuit 140 may receive a charging input (eg, a charging current or a charging voltage) from a charger through the USB interface 130 .

[0056] The power management module 141 is used to connect the battery 142, the charging circuit 140 and the processor 110. The power management module 141 receives input from the battery 142 and / or the charging circuit 140, and supplies power to the processor 110, the internal memory 121, the display screen 194, the camera 193, and the wireless communication module 160. The power management module 141 can also be used to monitor parameters such as battery capacity, battery cycle number, battery health status (leakage, impedance, cumulative charging time, etc.), battery temperature (specifically, it can be monitored by a temperature sensor set on the battery), etc.

[0057] In some embodiments, the power management module 141 may also be disposed in the processor 110. In other embodiments, the power management module 141 and the charging circuit 140 may also be disposed in the same device.

[0058] In addition, combined Figure 1 As shown, in order to enable the electronic device 10 to be coupled to the charger 20, the charger 20 may include a plug 200 plugged into the USB interface 130 of the electronic device. Figure 3 As shown, the above plug may be a Type-C interface. The Type-C interface may include Figure 3 The CC pin shown. The type of external device coupled to the Type-C interface can be identified through the CC pin. Figure 3 As shown, both the A side and the B side of the Type-C interface include two symmetrically arranged VBUS pins (used to provide USB voltage, pins 4 and 9, which are used as voltage output terminals in the embodiment of the present application), a CC pin (pin 5), a D+ pin (pin 6 on the A side and pin 7 on the B side), a D- pin (pin 7 on the A side and pin 6 on the B side)), and an SBU pin (pin 8 is a spare pin, where the A side is marked as SBU1 and the B side is marked as SBU2). In addition, the plug may also have other pins for grounding, idleness, etc., wherein when the plug 200 of the switching power supply 20 is inserted into the USB interface 130 of the electronic device 10, the electronic device 10 can be charged or powered.

[0059] To charge the battery, refer to Figure 4As shown, the power supply end of the charging circuit 140 is connected to the VBUS pin of the USB interface 130, and the charging end Vbat of the charging circuit 140 is connected to the battery 142. The processor 110 or the charging management module 141 can control the charging circuit 140 according to the charging protocol, and then the voltage of the power supply end is converted into a voltage Vbat near the battery voltage (for example, about 5V) through the charging circuit 140, and then the voltage Vbat is used to charge the battery 142. In addition, referring to Figure 4 As shown, it also includes a protection circuit 145 arranged between the USB interface 130 and the charging circuit 140, wherein the protection circuit 145 is provided with a protection threshold. When the electrical parameter of the power signal output by the charger exceeds the protection threshold, the protection circuit 145 can be triggered to disconnect, thereby disconnecting the path between the USB interface 130 and the charging circuit 140, stopping charging, and ensuring the safety and stability of the system.

[0060] It should be noted that in order to enable the above-mentioned electronic device to be coupled with an external device (such as a charger, an analog headset, a digital headset, a mobile storage device, a mobile terminal and other devices) through the USB interface 130. Usually, the power supply end of the charging circuit 140 is coupled to the VBUS pin. When an external charger is connected through the USB interface 130, the electronic device can negotiate the charging voltage with the charger through the charging protocol based on the CC pin, the D+ pin and the D- pin. For example, for a charger that supports the power delivery (PD) charging protocol, the charging parameters are negotiated through the CC pin; for a charger that supports the supercharger protocol (SCP), the charging parameters are negotiated through the D+ pin and the D- pin.

[0061] For electronic devices using lithium batteries, usually, if the battery is exhausted and not charged in time, the battery voltage will gradually decrease and enter an undervoltage state, and the battery voltage may even drop below 1.5V. In order to protect the battery, the charging management chip usually strictly limits the charging rate (= current / rated capacity) when charging again. At present, when the battery is in an undervoltage state, a constant current low current charging strategy is usually implemented, such as charging to 2.6V with 0.01C (usually ≤0.02C), and when the battery voltage reaches 2.6V, the normal fast charging process is enabled to continue charging. Among them, the undervoltage state is usually a state in which the voltage of the electronic device is lower than the rated charging voltage after the electronic device automatically shuts down or stands by when the power is 0% or close to 0%. Usually, for different models of batteries and different electronic devices, the voltage value entering the undervoltage state may be different. Usually, for a battery with a rated charging voltage of 4.3V, it usually enters the undervoltage state when the battery voltage is lower than 2.6V; in other scenarios of different models of batteries, the battery voltage can also enter the undervoltage state when it is lower than 3.0V or 2.8V.

[0062] Reference Figure 5 As shown in Table 1, a battery charging strategy is provided. Figure 6 As shown, in the undervoltage state, the battery is first charged with a constant current (CC) using a current I0. When the battery voltage reaches U0, the undervoltage state is exited and the normal voltage interval charging strategy is started to fast charge the battery in the normal voltage interval. In the normal voltage interval, the battery is first charged with a constant current at a higher charging rate I1 to a voltage of U1, and then the battery is charged alternately by constant current charging and constant voltage charging (CC). Usually, the charging rate is gradually reduced in the order of I1>I2>I3>I4>I5>I6>I7, and the charging voltage is gradually increased in the order of U1<U2<U3<U4<U5<U6, so that fast charging is achieved while ensuring battery safety and life. However, in order to ensure the safety of the battery in the undervoltage state, the battery is usually charged with a constant current at a smaller current I0 (usually set to ≤0.02C) in the undervoltage state, wherein the charging voltage U in the undervoltage state is gradually increased (U≤U0, U0 is between 0-2.6V) until the undervoltage state is exited.

[0063]

[0064] Table 1

[0065] Reference Figure 6 As shown, in the undervoltage state, that is, before the moment T1, the battery is charged with a small current I0=0.02C (wherein, in the embodiment of the present application, the charging current is expressed by the charging rate), and the charging voltage U is gradually increased to U0=2.6V to exit the constant current charging, and then the battery is charged according to the normal voltage range shown in Table 1 until the battery charging is terminated at the moment T2; it can be seen that in the above charging process, the charging time in the undervoltage state before T1 occupies a large proportion of the entire charging stage. That is, when the battery is in an undervoltage state, it takes too long to use a very small current constant current charging; in this way, when the battery is shut down due to undervoltage, it will affect the boot time, and sometimes even cause misdiagnosis of battery failure, which has a greater impact on the user experience; in addition, in the undervoltage state, simply using constant current charging is not conducive to the management of battery voltage polarization and will accelerate battery aging.

[0066] To solve the above problems, refer to Figure 7 As shown, an embodiment of the present application provides a charging control method, which is applied to a charging circuit, and the charging circuit is used to charge a battery of an electronic device. The method includes the following steps:

[0067] S101 . In an undervoltage state of a battery, controlling a charging circuit to continuously output a first current to the battery starting from a first moment.

[0068] Among them, from the first moment, the charging circuit is controlled to charge the battery with a first current in a constant current charging manner. For example, referring to Table 2, starting from the first moment, the battery is charged with a constant current by a first current I0 (for example, I0=0.01C, usually I0≤0.02C). The first moment can be the moment when the battery of the electronic device is turned off or on standby after the battery is consumed to a power level less than or equal to a predetermined value (for example, a predetermined value can be designed for different manufacturers to indicate that the power level is 0% or close to 0%), and the charger is inserted again for charging.

[0069]

[0070] Table 2

[0071] S102, the battery is in an undervoltage state, and the charging circuit is controlled to continuously output a second current to the battery from a second moment; the second moment is after the first moment, and the second current is greater than the first current.

[0072] Specifically, when it is determined that the voltage of the battery is a second voltage at the second moment, the charging circuit is controlled to output a second current to the battery, the second voltage is greater than the first voltage, and the first voltage is the voltage of the battery at the first moment.

[0073] For example, still referring to Table 2, at the second moment, the first current I0 of the constant current charging in the undervoltage state of the battery can be increased to I01 (for example, I01=0.2C, usually, I01≈0.025-1.0C), so as to improve the charging speed of the battery in the undervoltage state. Specifically, the second moment can be after the battery is charged with the first current I0 to the second voltage U01 at the first moment. In the above example, the first voltage can be less than or equal to the second voltage U01, and the second voltage U01 is less than or equal to the above U0 (≈0-2.6V). Of course, the first voltage is not fixed. When the battery enters the undervoltage state, as long as the battery is not charged by the charger, it can be considered that the battery voltage will continue to decrease; when the battery is charged with the first current I0, the battery voltage gradually increases. When the battery voltage is the second voltage U01, the second moment is entered, and the battery is charged with the larger current I01=0.2C. The difference between the second voltage and the first voltage is less than or equal to 200mv. In order to reduce the charging time, the constant current charging time of the battery with the first current needs to be as short as possible, and the difference between the second voltage and the first voltage needs to be as small as possible. For example, the battery can be charged with the first current, and when the battery voltage increases by 200mv, the battery can be charged with the second current at a constant current. Preferably, the battery can be charged with the second current at a constant current after the battery voltage increases by 50mv.

[0074] Different from the charging strategy shown in Table 1, as shown in Table 2, the charging control method provided in the embodiment of the present application has a charging current I 01 (I 01 ≈ 0.025-1.0C) when the battery is in an undervoltage state, which is higher than the charging current I 0 (usually ≤ 0.02C) provided by the charging strategy provided in Table 1. Therefore, when completing the same charging capacity, the charging time of the charging strategy provided in Table 2 is significantly shorter than the charging time of the charging strategy provided in Table 1.

[0075] Furthermore, in the charging strategy provided in Table 1, when the battery is under voltage, the charging process is all done with constant current charging, which is not conducive to timely eliminating the polarization voltage of the battery. The long-term uneven distribution of electrode potential will trigger the side reaction between the electrode and the electrolyte interface, thereby accelerating battery aging. In order to eliminate the polarization voltage of the battery, a constant voltage charging step can be added under the under voltage state. For details, refer to Figure 7 As shown, after step S102, the following steps are also included:

[0076] S103 . In an undervoltage state of the battery, controlling the charging circuit to continuously output a third voltage to the battery starting from a third moment, where the third moment is after the second moment.

[0077] At the third moment, it is determined that the voltage of the battery is the third voltage, and the charging circuit is controlled to output the third voltage to the battery, the third voltage is greater than the second voltage, and the second voltage is the voltage of the battery at the second moment. And, starting from the third moment, when the current output by the charging circuit to the battery is equal to the first current, normal charging is started and the undervoltage state is exited.

[0078] For example, still referring to Table 2, at the third moment, in the battery under-voltage state, when the battery voltage reaches the third voltage U0, the battery can be charged by constant voltage charging at the third voltage U0. In this way, since a section of constant voltage charging of the battery is added, the polarization voltage of the battery can be eliminated, and the side reaction between the lithium-ion battery electrode and the electrolyte interface can be effectively reduced, thereby reducing the impact on the battery life. In addition, as the constant voltage charging time continues, the charging current will gradually decrease until the charging current reaches the initial first current I 0 and then exits the under-voltage state, and normal charging is started to fast charge the battery in the normal voltage range. Specifically, referring to Table 2, the charging strategy for the normal voltage range can be the same as that in Table 1, which will not be repeated here.

[0079] In addition, in the undervoltage state, after the battery is charged with a constant current by the first current I0 until the battery voltage reaches U01, the battery can also be charged alternately by adding multiple constant current charging and constant voltage charging (CC) modes until the battery voltage and current meet the requirements to exit the undervoltage state. In this way, since multiple constant voltage charging stages are added, it is more conducive to eliminating the polarization voltage of the battery, effectively reducing the side reactions at the interface between the lithium-ion battery electrode and the electrolyte, thereby reducing the impact on the battery life.

[0080] In addition, the charging control method adopted in this scheme needs to ensure the safety of the battery while increasing the first current I0 to the second current I01 when charging the battery with a constant current. Therefore, the battery health status diagnosis can also be performed after charging starts in the undervoltage state, for example: Figure 7 As shown, the timing can be started from the first moment, and when it is determined that the accumulated time exceeds the time threshold, the charging circuit is controlled to stop charging. Since when there is an internal short circuit in the battery, the charging time in the undervoltage state will be significantly longer than that of a normal battery, the time threshold of the accumulated charging time can be set as a judgment threshold according to the difference in the undervoltage charging time of the battery internal short circuit sample and the normal battery sample. Once the accumulated charging time exceeds the time threshold, the charging is controlled to stop, avoiding battery safety issues.

[0081] In some examples, the charging control method adopted in this solution must ensure that there is no lithium dendrite precipitation at the negative electrode of the battery in the undervoltage state of the entire battery to avoid affecting the battery life. In the charging strategy shown in Table 2, the first current I 0, the second current I 01, the second voltage U01 and the third voltage U0 can use fixed values; of course, in order to further optimize the service life of the battery, the first current I 0, the second current I 01, the second voltage U01 and the third voltage U0 can also be adjusted dynamically in real time.

[0082] Reference Figure 7 As shown, the specific adjustment method is: obtaining characteristic parameters of the battery, the characteristic parameters including at least one or more of the following: temperature, number of cycles; obtaining one or more of the first current, the second current, the second voltage and the third voltage according to the characteristic parameters and the parameter table, wherein the parameter table contains one or more of the corresponding relationship between the characteristic parameter and the first current, the corresponding relationship between the characteristic parameter and the second current, the corresponding relationship between the characteristic parameter and the second current, and the corresponding relationship between the characteristic parameter and the second current.

[0083] Specifically, referring to Table 3, a charging solution library for the undervoltage state during the battery life cycle is provided, which is constructed by the corresponding relationship between the battery temperature, the number of cycles, and the first current I0, the second current I01, the second voltage U01 and the third voltage U0.

[0084]

[0085] Table 3

[0086] Taking the temperature T0-T1 and the cycle number cycle-0-cycle-1 in Table 3 as an example, the value of the first current I0 is I a1 , the value of the second current I01 is I a2 The value of the second voltage U01 is U a1 And the value of the third voltage U0 is U a2 When the detected temperature and the number of cycles meet the temperature T2 to T3 and the number of cycles cycle-1 to cycle-2 in Table 3, the value of the first current I0 is adjusted to I b1 , the value of the second current I01 is adjusted to I b2 , the value of the second voltage U01 is adjusted to U b1 And the value of the third voltage U0 is adjusted to U b2 . The temperature interval and cycle number interval set in Table 3 are for reference only. The temperature interval and cycle number interval can be reset according to battery performance and product requirements, and the number of alternating constant current charging and constant voltage charging can be increased. In this way, by dynamically adjusting the first current I0, the second current I01, the second voltage U01 and the third voltage U0 according to the two influencing factors of the real-time temperature and the number of cycles of the battery, it is beneficial to optimize the battery life; of course, more battery parameters can also be combined when constructing Table 3, for example, the real-time battery full charge capacity can also be used as an influencing factor to screen the charging strategy.

[0087] Of course, the above Table 3 needs to be obtained by calibrating the charging strategy of the undervoltage state of the battery throughout its life cycle, or by machine learning training. A three-electrode battery can be made by pre-embedded lithium reference electrode inside the battery, such as Figure 8 As shown, according to theoretical calculations and experimental test results, when the negative electrode voltage is greater than 0V during the entire charging process, that is, there is no dendrite precipitation, the battery is charged using the scheme provided by the embodiment of the present application (i.e., the charging strategy provided in Table 2) and the scheme provided in Table 1 to measure the positive and negative voltage curves of the battery. Based on the calibration results of the negative electrode voltage curve during the charging process, on the premise of meeting the charging time requirements, the smaller value of the maximum charging rate I01 in the undervoltage state (the battery power is less than 0%) is taken as the corresponding scheme, and a charging scheme library for the undervoltage state during the life cycle is established as shown in Table 3.

[0088] Specifically, two examples are provided below, respectively, combining a 4.0Ah-4.3V voltage system lithium-ion battery as a sample and a 3.0Ah-4.3V voltage system lithium-ion battery as a sample charging control method:

[0089] Example 1: Take a 4.0Ah-4.3V lithium-ion battery as a sample. When the charging rate is 1.0C, the current is 4.0A and the rated charging voltage is 4.3V. The current temperature is 25℃ and the cycle is 100 cycles.

[0090] refer to Figure 8 The method shown in the figure is to make a three-electrode battery by pre-burying a lithium reference electrode inside the battery. According to theoretical calculations and experimental test results, the negative electrode voltage is greater than 0V during the entire charging process, that is, there is no dendrite precipitation at the negative electrode, and the charging strategy shown in Table 2 is used for charging control. Based on the calibration results of the negative electrode voltage curve during the charging process, and on the premise of meeting the charging time requirements, a charging scheme library under the undervoltage state within the life cycle of the battery is established as shown in Table 4.

[0091]

[0092] Table 4

[0093] Thus, referring to the charging strategy shown in Table 5 and Fig. 9 The charging control process is described as follows: the battery temperature is detected to be 25°C and the battery cycle number is 100 cycles. The dynamic charging strategy for the battery undervoltage state can be matched in the solution library of Table 4, that is, Table 5, where I0=0.01C, U01=1.29V; I01=0.2C, U0=2.59V.

[0094]

[0095] Table 5

[0096] Combination Fig. 9 and Fig.10As shown, a charging control method provided by an embodiment of the present application is: the charging process in the undervoltage state includes: 1) 0.01C constant current charging to 1.29V; 2) 0.2C constant current charging to 2.59V, 2.59V constant voltage charging to 0.01C. The charging process in the normal voltage range includes: 1) 3.63C constant current charging to 4.09V; 2) 3.5C constant current charging to 4.09V, 4.09V constant voltage charging to 2.5C; 3) 2.5C constant current charging to 4.14V, 4.14V constant voltage charging to 2.0C; 4) 2.0C constant current charging to 4.24V, 4.24V constant voltage charging to 1.5C; 5) 1.5C constant current charging to 4.29V, 4.29V constant voltage charging to 1.2C; 6) 1.2C constant current charging to 4.30V, 4.30V constant voltage charging to 0.193C, and the charging is completed. Of course, the charging process under the above-mentioned normal voltage range is only an example. It can be understood that the charging strategy in the above-mentioned normal voltage range is only an example. When it is necessary to further reduce the charging time, other charging strategies can also be adopted. The embodiments of the present application mainly improve the charging under the undervoltage state, and are not limited to the charging strategy in the normal voltage range.

[0097] Relative to the charging strategy provided in Table 1, when applied to a 4.0Ah-4.3V voltage system lithium-ion battery, the specific current and voltage at each stage are shown in Table 6:

[0098]

[0099] Table 6

[0100] Among them, combined Fig.10 As shown, the charging process in the undervoltage state includes: 0.01C constant current charging to 2.59V. The charging process in the normal voltage range includes: 1) 3.63C constant current charging to 4.09V; 2) 3.5C constant current charging to 4.09V, 4.09V constant voltage charging to 2.5C; 3) 2.5C constant current charging to 4.14V, 4.14V constant voltage charging to 2.0C; 4) 2.0C constant current charging to 4.24V, 4.24V constant voltage charging to 1.5C; 5) 1.5C constant current charging to 4.29V, 4.29V constant voltage charging to 1.2C; 6) 1.2C constant current charging to 4.30V, 4.30V constant voltage charging to 0.193C, and the charging is completed.

[0101] Table 5, Table 6 and Fig.10The comparison results of the measured charging data show that the full charging time corresponding to the scheme provided in Table 5 at a temperature of 25°C is 56 minutes, and the full charging time corresponding to the scheme provided in Table 5 is 73 minutes. Obviously, the charging speed of the charging method provided by the scheme provided in Table 5 has been greatly improved. The reason is that the scheme provided in Table 5 increases the charging rate when the battery is in an undervoltage state, and the charging time in the undervoltage state (7 minutes) is greatly reduced, thereby improving the user experience. At the same time, the scheme provided in Table 5 increases constant voltage charging (2.59V constant voltage charging to 0.01C) under the undervoltage state, which can eliminate the influence of voltage polarization in time. Therefore, the scheme provided in Table 5, on the basis of greatly improving the charging speed, also greatly reduces the voltage polarization effect, effectively inhibits the side reactions at the interface between the positive electrode and the electrolyte, thereby reducing the impact on the life of the lithium-ion battery. Fig.11 As shown, the effects of the charging strategies provided in Table 5 and Table 6 on the battery cycle capacity are tested at the same time. It can be seen that the solution provided in Table 5 does not affect the battery cycle life after increasing the charging rate in the undervoltage state.

[0102] Example 2: Take a 3.0Ah-4.3V voltage system lithium-ion battery as a sample, when the charging rate is 1.0C, the current is 3.0A, and the rated charging voltage is 4.3V. The current battery ambient temperature is 25℃, and the cycle period is 180 cycles.

[0103] refer to Figure 8 The method shown in the figure is to make a three-electrode battery by pre-burying a lithium reference electrode inside the battery. According to theoretical calculations and experimental test results, the negative electrode voltage is greater than 0V during the entire charging process, that is, there is no dendrite precipitation at the negative electrode, and the charging strategy shown in Table 2 is used for charging control. Based on the calibration results of the negative electrode voltage curve during the charging process, and on the premise of meeting the charging time requirements, a charging scheme library under the undervoltage state within the life cycle of the battery is established as shown in Table 7.

[0104]

[0105] Table 7

[0106] Thus, referring to the charging strategy shown in Table 8 and Fig.12 The charging control process is described as follows: the battery temperature is detected to be 25°C and the battery cycle number is 180 cycles. The dynamic charging strategy for the battery undervoltage state can be matched in the solution library in Table 7, that is, Table 8, where I0=0.015C, U01=1.29V; I01=0.2C, U0=2.59V.

[0107]

[0108] Table 8

[0109] Combination Fig.12 and Fig.13As shown, a charging control method provided by an embodiment of the present application is: the charging process in the undervoltage state includes: 0.015C CC to 2.59V. The charging process in the normal voltage range includes: 1) 3.63C constant current charging to 4.09V; 2) 3.5C constant current charging to 4.09V, 4.09V constant voltage charging to 2.5C; 3) 2.5C constant current charging to 4.14V, 4.14V constant voltage charging to 2.0C; 4) 2.0C constant current charging to 4.24V, 4.24V constant voltage charging to 1.5C; 5) 1.5C constant current charging to 4.29V, 4.29V constant voltage charging to 1.2C; 6) 1.2C constant current charging to 4.30V, 4.30V constant voltage charging to 0.193C, and charging is completed.

[0110] Relative to the charging strategy provided in Table 1, when applied to a 3.0Ah-4.3V voltage system lithium-ion battery, the specific current and voltage at each stage are shown in Table 9:

[0111]

[0112] Table 9

[0113] Among them, combined Fig.13 As shown, the charging process in the undervoltage state includes: 1) 0.015C constant current charging to 1.29V; 2) 0.2C constant current charging to 2.59V, 2.59V constant voltage charging to 0.015C. The charging process in the normal voltage range includes: 1) 3.63C constant current charging to 4.09V; 2) 3.5C constant current charging to 4.09V, 4.09V constant voltage charging to 2.5C; 3) 2.5C constant current charging to 4.14V, 4.14V constant voltage charging to 2.0C; 4) 2.0C constant current charging to 4.24V, 4.24V constant voltage charging to 1.5C; 5) 1.5C constant current charging to 4.29V, 4.29V constant voltage charging to 1.2C; 6) 1.2C constant current charging to 4.30V, 4.30V constant voltage charging to 0.193C, and the charging is completed.

[0114] Table 8, Table 9 and Fig.13The comparison results of the measured charging data show that at a temperature of 25°C, the full charging time corresponding to the scheme provided in Table 8 is 49 minutes, and the full charging time corresponding to the scheme provided in Table 9 is 68 minutes. Obviously, the charging speed of the charging method provided by the scheme provided in Table 8 has been greatly improved. The reason is that the scheme provided in Table 8 increases the charging rate when the battery is in an undervoltage state, and the charging time (4 minutes) in the undervoltage state is greatly reduced, thereby improving the user experience. At the same time, the scheme provided in Table 8 increases constant voltage charging (2.59V constant voltage charging to 0.01C) under the undervoltage state, which can eliminate the influence of voltage polarization in time. Therefore, the scheme provided in Table 8, on the basis of greatly improving the charging speed, also greatly reduces the voltage polarization effect, effectively inhibits the side reactions at the interface between the positive electrode and the electrolyte, thereby reducing the impact on the life of the lithium-ion battery. Fig.14 As shown, the effects of the charging strategies provided in Tables 8 and 9 on the battery cycle capacity are tested at the same time. It can be seen that the scheme provided in Table 8 does not affect the battery cycle life after increasing the charging rate in the undervoltage state. The difference between Example 2 and Example 1 is that the cut-off current (rate) of the constant voltage charging step in the undervoltage state is increased from 0.01C to 0.015C.

[0115] It is understandable that in order to implement the above-mentioned charging control method, a charging control device is provided, which includes a hardware structure and / or software module corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm operations of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0116] The embodiment of the present application can divide the functional modules of the charging control device according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0117] For example, when the functional modules are divided in an integrated manner, the charging control device can be the electronic device itself or a chip or system on chip in the electronic device, or other combined devices, components, etc. that can realize the functions of the above-mentioned charging control device. The charging control device can be used to perform the functions involved in the above-mentioned embodiments.

[0118] As a possible implementation manner, the charging control device may include: a first processing module, used to execute step S101; a second processing module, used to execute step S102; and a third processing module, used to execute step S105.

[0119] Among them, all relevant contents of each operation involved in the above method embodiment can be referred to the functional description of the corresponding functional module, and will not be repeated here.

[0120] In this embodiment, the electronic device can be presented in the form of various functional modules divided in an integrated manner. The "module" here can refer to a specific ASIC, circuit, processor and memory that executes one or more software or firmware programs, integrated logic circuit, and / or other devices that can provide the above functions. In a simple embodiment, a person skilled in the art can imagine that the electronic device can be presented in the form of various functional modules divided in an integrated manner. Figure 2 The electronic device is shown in the form of an electronic device.

[0121] for example, Figure 2 The processor 110 in the electronic device can call the computer execution instructions stored in the internal memory 121 to enable the electronic device to execute the charging control method in the above method embodiment.

[0122] For example, the charging control device may be Figure 2 The processor 110, power management module 141 or charging management chip shown in the figure, the function / implementation process of the charging control device can be Figure 2 The processor 110 in the embodiment calls the computer execution instructions stored in the internal memory 121 to implement it.

[0123] Since the charging control device provided in this embodiment can execute the above-mentioned charging control method, the technical effects that can be obtained can refer to the above-mentioned method embodiment, which will not be repeated here.

[0124] Optionally, an embodiment of the present application further provides a charging control device (for example, the charging control device may be a chip or a chip system). When the charging control device is a chip system, it may be composed of chips, or may include chips and other discrete devices. The embodiment of the present application does not specifically limit this.

[0125] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or may contain one or more servers, data centers and other data storage devices that can be integrated with the medium. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)), etc. In the embodiment of the present application, the computer may include the aforementioned device.

[0126] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in a claim. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0127] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A charging control method, applied to a charging circuit, wherein the charging circuit is used to charge a battery of an electronic device, characterized in that: The method includes: In an undervoltage state of the battery, controlling the charging circuit to continuously output a first current to the battery starting from a first moment; When the battery is in an undervoltage state, the charging circuit is controlled to continuously output a second current to the battery starting from a second moment; the second moment is located after the first moment, and the second current is greater than the first current.

2. The charging control method according to claim 1, characterized in that: The method further includes: in an undervoltage state of the battery, controlling the charging circuit to continuously output a third voltage to the battery starting from a third moment, the third moment being after the second moment.

3. The charging control method according to claim 1 or 2, characterized in that: The method further includes: at the second moment, determining that the voltage of the battery is a second voltage, controlling the charging circuit to output the second current to the battery, the second voltage being greater than the first voltage, and the first voltage being the voltage of the battery at the first moment.

4. The charging control method according to claim 3, characterized in that: A difference between the second voltage and the first voltage is less than or equal to 200 mv.

5. The charging control method according to claim 3, characterized in that: The method also includes: at the third moment, determining that the voltage of the battery is a third voltage, controlling the charging circuit to output the third voltage to the battery, the third voltage being greater than the second voltage, and the second voltage being the voltage of the battery at the second moment.

6. The charging control method according to claim 2, characterized in that: The method further includes: starting from the third moment, when the current output by the charging circuit to the battery is equal to the first current, starting normal charging.

7. The charging control method according to any one of claims 1 to 6, characterized in that: The method further comprises: Acquire characteristic parameters of the battery, wherein the characteristic parameters include at least one or more of the following: temperature and cycle number; The first current is acquired according to the characteristic parameter and a parameter table, wherein the parameter table includes a corresponding relationship between the characteristic parameter and the first current.

8. The charging control method according to any one of claims 1 to 6, characterized in that: The method further comprises: Acquire characteristic parameters of the battery, wherein the characteristic parameters include at least one or more of the following: temperature and cycle number; The second current is acquired according to the characteristic parameter and a parameter table, wherein the parameter table includes a corresponding relationship between the characteristic parameter and the second current.

9. The charging control method according to claim 3, characterized in that: The method further comprises: Acquire characteristic parameters of the battery, wherein the characteristic parameters include at least one or more of the following: temperature and cycle number; The second voltage is acquired according to the characteristic parameter and a parameter table, wherein the parameter table includes a corresponding relationship between the characteristic parameter and the second current.

10. The charging control method according to claim 5, characterized in that: The method further comprises: Acquire characteristic parameters of the battery, wherein the characteristic parameters include at least one or more of the following: temperature and cycle number; The third voltage is acquired according to the characteristic parameter and a parameter table, wherein the parameter table includes a corresponding relationship between the characteristic parameter and the second current.

11. The charging control method according to any one of claims 1 to 10, characterized in that: The method further includes: starting timing from the first moment, and when it is determined that the accumulated time exceeds a time threshold, controlling the charging circuit to stop charging.

12. The charging control method according to any one of claims 1 to 11, characterized in that: In the undervoltage state, the voltage of the battery is less than or equal to 3.0V.

13. The charging control method according to any one of claims 1 to 12, characterized in that: In the undervoltage state, the power level of the battery is less than or equal to a predetermined power level.

14. A charging control device, applied to electronic equipment, characterized in that: Used to execute the charging control method as described in any one of claims 1-13.

15. A chip, characterized in that: Comprising the charging control device as claimed in claim 14.

16. An electronic device, characterized in that: It includes a battery and a charging circuit, wherein the charging circuit is connected to the battery; and further includes: the charging control device as claimed in claim 14, wherein the charging control device is connected to the charging circuit.

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