CN114174844B

CN114174844B - Charging control method and device, charging test method and system and electronic equipment

Info

Publication number: CN114174844B
Application number: CN201980098772.4A
Authority: CN
Inventors: 谢红斌; 林尚波
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2023-12-22
Anticipated expiration: 2039-08-30
Also published as: WO2021035736A1; CN114174844A

Abstract

The invention provides a charging control method and device, a charging test method and system and electronic equipment. The charging control method comprises the following steps: acquiring the charging state of a battery cell, and charging the battery cell by using the charging current corresponding to the charging state according to the corresponding relation between the pre-stored charging state and the charging current; the corresponding relation between the pre-stored charging state and the charging current is that the test charging current of the battery cell is adjusted according to the monitored lithium precipitation state of the battery cell cathode, the corresponding test charging state is recorded, and the generated corresponding relation between the test charging state and the test charging current is used as the corresponding relation between the pre-stored charging state and the charging current. The invention realizes the quick charging of the battery core and ensures the charging safety of the battery core.

Description

Charging control method and device, charging test method and system and electronic equipment

Technical Field

The present invention relates to the field of electronic devices, and in particular, to a charging control method and apparatus, a charging test method and system, and an electronic device.

Background

The current charging method commonly used in lithium batteries is a constant voltage charging method at a certain potential after continuously charging to the certain potential by a preset constant current. This charging method causes the anode potential to drop continuously, and lithium ions are reduced to lithium metal on the anode surface and precipitated. The lithium dendrites generated at this time accumulate on the electrode surface, thereby greatly threatening the safety performance of the battery.

Disclosure of Invention

The invention aims to ensure the charging safety of the battery cell while rapidly charging the battery cell.

According to one aspect of the present disclosure, there is provided a charge control method including:

acquiring a charging state of a battery cell, wherein the charging state is a battery cell voltage or a battery cell charging state;

charging the battery cell with the charging current corresponding to the charging state according to the pre-stored corresponding relation between the charging state and the charging current; the method for acquiring the corresponding relation between the pre-stored charging state and the charging current comprises the following steps: and adjusting the test charging current of the battery cell according to the monitored lithium precipitation state of the negative electrode of the battery cell, recording the corresponding test charging state, and taking the corresponding relation between the generated test charging state and the test charging current as the corresponding relation between the pre-stored charging state and the charging current.

According to another aspect of the present disclosure, there is provided a charge control device including:

the device comprises an acquisition unit, a control unit and a control unit, wherein the acquisition unit is used for acquiring the charging state of the battery cell, wherein the charging state is the battery cell voltage or the charging state of the battery cell;

the adjusting unit is used for charging the battery cell according to the corresponding relation between the pre-stored charging state and the charging current corresponding to the charging state;

The method for acquiring the corresponding relation between the pre-stored charging state and the charging current comprises the following steps: and adjusting the test charging current of the battery cell according to the monitored lithium precipitation state of the negative electrode of the battery cell, recording the corresponding test charging state, and taking the corresponding relation between the generated test charging state and the test charging current as the corresponding relation between the pre-stored charging state and the charging current.

According to another aspect of the present disclosure, an electronic device is provided, including a battery cell, a charging circuit, a storage unit, and a processing unit;

the storage unit is used for storing a charging control program;

and the processing unit is used for running a charging control program, and when the charging control program is executed, the charging control method is run so as to control the charging circuit to charge the battery cell.

According to another aspect of the present disclosure, a charge test system for performing a charge test on a cell having a positive electrode, a negative electrode, and a reference electrode is presented, the charge test system comprising:

the voltage detection device is provided with two input ends and an output end, the two input ends of the voltage detection device are respectively connected with the negative electrode of the battery cell and the reference electrode, the potential of the reference electrode is the ground potential of the voltage detection device, and the output end of the voltage detection device is used for outputting the voltage of the negative electrode of the battery cell;

The charging device is provided with a signal receiving end and a charging end, the signal receiving end is connected with the output end of the voltage detection device, the charging end is connected with the anode and the cathode of the battery cell, and the potential of the voltage of the cathode is the ground potential of the charging device; and the charging device adjusts the test charging current of the battery cell according to the negative electrode voltage detected by the voltage detection device.

According to another aspect of the present disclosure, there is provided a method of testing charging, the method comprising:

acquiring the negative voltage of the battery cell and a reference electrode every third preset time period, and confirming the lithium precipitation state of the battery cell according to the negative voltage of the battery cell;

in each third preset time period, according to the lithium precipitation state of the negative electrode of the battery cell, adjusting the test charging current of the battery cell, and recording the test charging state of the battery cell corresponding to the test charging current;

and generating a corresponding relation between the test charging current and the battery cell test charging state.

According to another aspect of the present disclosure, there is provided a readable storage medium comprising:

a memory storing a charge control program;

and the processor runs a charging control program, and when the charging control program is executed, the charging control method is run.

a memory storing a charge test program;

and the processor runs a charging control program, and when the charging control program is executed, the charging test method is run.

In the embodiment, in the process of testing the corresponding relation between the pre-stored charging state and the charging current, the test charging current of the battery cell is adjusted according to the monitored lithium precipitation state of the battery cell cathode, and the lithium precipitation state of the battery cell cathode is monitored to maximize the charging current on the premise of ensuring the charging safety of the battery cell, so that the lithium precipitation phenomenon of the battery cell cathode can be prevented or reduced. Therefore, the embodiment can give consideration to the safety performance and the charging speed of the battery cell.

Drawings

FIG. 1 is a schematic diagram of an embodiment of an electronic device of the present disclosure;

FIG. 2 is a block diagram of a circuit configuration of an embodiment of an electronic device of the present disclosure;

FIG. 3 is a flow chart of an embodiment of a charge control method of the present disclosure;

FIG. 4 is a test flow chart for testing a pre-stored state of charge versus charge current;

FIG. 5 is a graph illustrating a pre-stored charge voltage versus charge current;

FIG. 6 is a graph showing the correspondence between pre-stored charging voltages and charging currents corresponding to two different charging times;

FIG. 7 is a system architecture diagram of an electronic device of the present disclosure;

fig. 8 is a block diagram of the structure of the charge control device of the present disclosure;

FIG. 9 is a schematic diagram of the structure of the charge test system of the present disclosure;

fig. 10 is a flow chart of an embodiment of a charge test method of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus a repetitive description thereof will be omitted.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the present disclosure. One skilled in the relevant art will recognize, however, that the aspects of the disclosure may be practiced without one or more of the specific details, or with other methods, components, devices, steps, etc. In other instances, well-known structures, methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure.

In the present disclosure, unless explicitly specified and limited otherwise, the terms "coupled," "connected," and the like are to be construed broadly, and may be fixedly attached, detachably attached, or integrally formed, for example; can be electrically connected or communicated with each other; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in this disclosure will be understood by those of ordinary skill in the art as the case may be.

Furthermore, in the description of the present disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless specifically defined otherwise. "and/or" describes an association relationship of an associated object, meaning that there may be three relationships, e.g., a and/or B, and that there may be a alone, B alone, and both a and B. The symbol "/" generally indicates that the context-dependent object is an "or" relationship. The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

The present disclosure proposes an electronic device, which may be an intelligent terminal or a communication terminal. The terminal or communication terminal includes, but is not limited to, a device configured to receive/transmit communication signals via a wireline connection, such as via a public-switched telephone network (public switched telephonenetwork, PSTN), a digital subscriber line (digital subscriber line, DSL), a digital cable, a direct cable connection, and/or another data connection/network and/or via a wireless interface, for example, for a cellular network, a wireless local area network (wireless local area network, WLAN), a digital television network such as a digital video broadcasting-handheld digital video broadcasting handheld, DVB-H, network, a satellite network, an amplitude modulation-frequency modulation (amplitude modulation-frequency modulation, AM-FM) broadcast transmitter, and/or another communication terminal. A communication terminal configured to communicate via a wireless interface may be referred to as a "wireless communication terminal," wireless terminal, "and/or" smart terminal. Examples of smart terminals include, but are not limited to, satellites or cellular telephones; a personal communications system (personal communication system, PCS) terminal that may combine a cellular radiotelephone with data processing, facsimile and data communications capabilities; a personal digital assistant (Personal Digital Assistant, PDA) that may include a radiotelephone, pager, internet/intranet access, web browser, organizer, calendar, and/or a global positioning system (global positioning system GPS) receiver; and conventional laptop and/or palmtop receivers or other electronic devices that include a radiotelephone transceiver. In addition, the terminal can further comprise, but is not limited to, chargeable electronic devices with charging functions, such as electronic book readers, intelligent wearable devices, mobile power sources (such as charger, travel charger), electronic cigarettes, wireless mice, wireless keyboards, wireless headphones, bluetooth sound boxes and the like. In the following embodiments, an electronic device is described as a mobile phone.

A related adapter for charging an electronic device in the related art is described below.

In the related art, the adapter may operate in a constant voltage mode, and the output voltage thereof is maintained substantially constant, such as 5V, 9V, 12V, 20V, or the like. The output current can be a pulsating direct current (direction is unchanged, amplitude value changes with time), an alternating current (both direction and amplitude value change with time) or a constant direct current (both direction and amplitude value do not change with time). The voltage output by the associated adapter is not suitable for direct loading to the two ends of the battery, but is required to be converted by a conversion circuit in the electronic device to obtain the charging voltage and/or the charging current expected by the battery in the electronic device.

The adapter may also operate in a voltage-following manner. The adapter and the electronic equipment to be charged are in bidirectional communication, and the adapter adjusts the voltage and the current output by the adapter according to the charging voltage and the charging current required by the feedback of the electronic equipment, so that the output voltage and the output current can be directly loaded on a battery of the electronic equipment to charge the battery, and the electronic equipment does not need to readjust the charging voltage and the charging current again.

The conversion circuit may control the charging voltage and/or the charging current of the battery at different charging phases. For example, during a constant current charging phase, the conversion circuit may utilize a current feedback loop such that the magnitude of the current into the battery meets the magnitude of the first charging current expected by the battery. In the constant voltage charging phase, the conversion circuit may utilize a voltage feedback loop so that the magnitude of the voltage applied across the battery meets the magnitude of the charging voltage expected by the battery. During the trickle charge phase, the conversion circuit may utilize a current feedback loop such that the magnitude of the current into the battery meets the magnitude of a second charging current (the second charging current is less than the first charging current) expected for the battery.

For example, when the voltage output by the relevant adapter is greater than the expected charging voltage of the battery, the conversion circuit is configured to perform a step-down conversion process on the voltage output by the relevant adapter, so that the magnitude of the charging voltage obtained after the step-down conversion meets the magnitude of the expected charging voltage of the battery.

The battery of the electronic device is charged in a "normal charging mode" or a "quick charging mode". The normal charging mode refers to the adapter outputting a relatively small current value (typically less than 2.5A) or charging a battery in a device to be charged with relatively small power (typically less than 15W). In the normal charging mode, it is often necessary to take several hours to fully charge a larger capacity battery (e.g., a 3000 milliamp capacity battery). The fast charge mode refers to the adapter being able to output a relatively large current (typically greater than 2.5A, such as 4.5A,5A or even higher) or to charge a battery in a device to be charged with a relatively large power (typically 15W or more). Compared with the common charging mode, the charging speed of the adapter in the quick charging mode is higher, and the charging time required for completely filling the batteries with the same capacity can be obviously shortened.

The wireless charging system and the wired charging system in the related art are described below, respectively.

In the wireless charging process, a power supply device (such as an adapter) is generally connected to a wireless charging device (such as a wireless charging base), and the output power of the power supply device is transmitted to an electronic device in a wireless manner (such as electromagnetic signals or electromagnetic waves) through the wireless charging device, so as to perform wireless charging on the electronic device.

According to the different wireless charging principles, the wireless charging modes mainly include three modes of magnetic coupling (or electromagnetic induction), magnetic resonance and radio waves. Currently, the mainstream wireless charging standards include QI standard, power entity alliance (Power Matters Alliance, PMA) standard, wireless power alliance (Alliance for Wireless Power, A4 WP). The QI standard and the PMA standard are both wirelessly charged by adopting a magnetic coupling mode. The A4WP standard uses magnetic resonance for wireless charging.

In the wired charging process, a power supply device (such as an adapter) is generally connected to an electronic device through a cable, and electric energy provided by the power supply device is transmitted to the electronic device through the cable to charge the electronic device.

The following describes the currently prevailing Constant Current Constant Voltage (CCCV) charging mode, which is applicable to both wired and wireless charging.

The charging process of the battery may include: a trickle charge phase (or mode), a constant current charge phase (or mode), a constant voltage charge phase (or mode), and a supplemental charge phase (or mode).

In the trickle charge phase, the fully discharged battery is pre-charged (i.e., restorative charge), the trickle charge current is typically one tenth of the constant current charge current, and when the battery voltage rises above the trickle charge voltage threshold, the charge current is increased to enter the constant current charge phase.

In the constant current charging stage, the battery is charged with a constant current, the charging voltage rises rapidly, and when the charging voltage reaches the charging voltage threshold expected by the battery, the constant voltage charging stage is shifted. The constant current is typically a nominal charge rate current, such as a high rate 3C current, where C is the battery capacity. Assuming that the battery capacity is 1700mAh, the constant current is 3×1700ma=5.1a.

In the constant voltage charging phase, the battery is charged at a constant voltage, the charging current gradually decreases, and when the charging current decreases to a set current threshold, the battery is fully charged. In CCCV charging mode, the current threshold is typically set to 0.01C, where C is the battery capacity. Still assuming a battery capacity of 1700mAh, the current threshold is 0.01 x 1700ma=17ma.

When the battery is fully charged, partial current loss occurs due to the self-discharge effect of the battery, and the charging stage is switched to the supplementary charging stage. During the recharge phase, the charge current is small, simply to ensure that the battery is in a full charge state.

It should be noted that the constant current charging phase does not require the charging current to be kept completely constant, and may, for example, refer to that the peak value or the average value of the charging current remains constant over a period of time. In practice, the constant current charging stage may employ a segmented constant current charging (Multi-stage constant current charging) approach.

The segmented constant current charging may have M constant current phases (M is an integer not less than 2), the segmented constant current charging starts the first phase charging with a predetermined charging current, the M constant current phases of the segmented constant current charging are sequentially executed from the first phase to the mth phase, and when a previous one of the constant current phases is shifted to a next constant current phase, the current magnitude may become small; when the battery voltage reaches the charge termination voltage threshold, the previous constant current stage of the constant current stages is shifted to the next constant current stage. The current conversion process between two adjacent constant current stages can be gradual, or can be stepwise jump.

For electronic devices that include a single battery, the heating phenomenon of the electronic device is severe when the single battery is charged with a large charging current. In order to ensure the charging speed of the electronic equipment and relieve the heating phenomenon of the electronic equipment in the charging process, the battery structure can be modified, a plurality of battery cells which are mutually connected in series are used, and the plurality of battery cells are directly charged, namely, the voltage output by the adapter is directly loaded to the two ends of a battery unit comprising the plurality of battery cells. Compared with a single-cell scheme (namely, the capacity of a single cell before improvement is considered to be the same as the total capacity of a plurality of cells connected in series after improvement), if the same charging speed is to be achieved, the charging current required by the multiple-section cells is about 1/N of the charging current required by the single cell (N is the number of the cells connected in series), in other words, the magnitude of the charging current can be greatly reduced by connecting the multiple-section cells in series on the premise of ensuring the same charging speed, so that the heating value of the electronic equipment in the charging process is further reduced.

Please refer to fig. 1 and 2. The electronic device may include a rear housing 11, a display screen 12, a circuit board, a battery. Note that the electronic device is not limited to include the above. Wherein the rear housing 11 may form an outer contour of the electronic device. In some embodiments, the rear housing 11 may be a metal rear housing, such as a metal of magnesium alloy, stainless steel, or the like. It should be noted that the material of the rear case 11 in the embodiment of the present application is not limited thereto, and other manners may be adopted, for example: the rear case 11 may be a plastic rear case, a ceramic rear case, a glass rear case, or the like.

Wherein the display screen 12 is mounted in the rear housing 11. The display screen 12 is electrically connected to the circuit board to form a display surface of the electronic device. In some embodiments, the display surface of the electronic device may be provided with a non-display area, such as: the top and/or bottom of the electronic device may form a non-display area, that is, the electronic device forms a non-display area on the upper portion and/or the lower portion of the display screen 12, and the electronic device may mount a camera, a receiver, or the like on the non-display area. It should be noted that the display surface of the electronic device may not be provided with a non-display area, that is, the display screen 12 may be a full screen. The display screen can be paved on the whole display surface of the electronic equipment, so that the display screen can be displayed on the display surface of the electronic equipment in a full screen mode.

The display 12 may be one or a combination of several of a liquid crystal display, an organic light emitting diode display, an electronic ink display, a plasma display, and a display using other display technologies. The display 12 may include an array of touch sensors (i.e., the display 12 may be a touch-sensitive display). The touch sensor may be a capacitive touch sensor formed of an array of transparent touch sensor electrodes, such as Indium Tin Oxide (ITO) electrodes, or may be a touch sensor formed using other touch technologies, such as acoustic wave touch, pressure sensitive touch, resistive touch, optical touch, etc., as embodiments of the present application are not limited.

It should be noted that, in some embodiments, a cover plate may be disposed on the display screen 12, and the cover plate may cover the display screen 12 to protect the display screen 12. The cover may be a transparent glass cover so that the display 12 displays through the cover. In some embodiments, the cover plate may be a glass cover plate made of a material such as sapphire. In some embodiments, after the display screen 12 is mounted on the rear case 11, a receiving space is formed between the rear case 11 and the display screen 12, and the receiving space may receive components of the electronic apparatus, such as a circuit board, a battery, and the like. The circuit board is mounted in the rear housing 11, and may be a main board of the electronic device, and one, two or more of a motor, a microphone, a speaker, an earphone interface, a universal serial bus interface, a camera, a distance sensor, an ambient light sensor, a receiver, a processing unit, and other functional devices may be integrated on the circuit board.

In some embodiments, the circuit board may be secured within the rear housing 11. Specifically, the circuit board may be screwed to the rear case 11 by a screw, or may be snap-fitted to the rear case 11 by a snap-fit method. It should be noted that the manner in which the circuit board is specifically fixed to the rear case 11 in the embodiment of the present application is not limited thereto, and may be other manners, such as a manner of being fixed together by a buckle and a screw. Wherein a battery is mounted in the rear case 11, and the battery 11 is electrically connected with the circuit board to supply power to the electronic device. The rear case 11 may serve as a battery cover of the battery. The rear case 11 covers the battery to protect the battery, reducing damage to the battery due to collision, drop, etc. of the electronic device.

Referring to fig. 2, fig. 2 is a block diagram of an electronic device according to an embodiment of the present application. The electronic device may comprise a storage and processing circuit 131, the storage and processing circuit 131 may be integrated on a circuit board. The storage and processing circuit 131 may include storage units such as hard disk drive storage units, non-volatile storage units (e.g., flash memory or other electronically programmable read-only memory units used to form solid state drives, etc.), volatile storage units (e.g., static or dynamic random access memory units, etc.), and the like, as embodiments of the present application are not limited. Processing circuitry in the storage and processing circuitry 131 may be used to control the operation of the electronic device. The processing circuitry may be implemented based on one or more micro-processing units, microcontrollers, digital signal processing units, baseband processing units, power management units, audio codec chips, application specific integrated circuits, display driver integrated circuits, and the like.

The storage and processing circuitry 131 may be used to run software in the electronic device such as internet browsing applications, voice over internet protocol (Voice over Internet Protocol, VOIP) telephone call applications, email applications, media playing applications, operating system functions, and the like.

The electronic device may include an input-output circuit 132, and the input-output circuit 132 may be disposed on a circuit board. The input-output circuit 132 is operable to cause the electronic device to effect input and output of data, i.e., to allow the electronic device to receive data from the external device and also to allow the electronic device to output data from the electronic device to the external device. The input-output circuit 132 may further include a sensor 1321. The sensors 1321 may include ambient light sensors, light and capacitance based proximity sensors, touch sensors (e.g., light based touch sensors and/or capacitive touch sensors, where the touch sensors may be part of a touch display or may be used independently as a touch sensor structure), acceleration sensors, temperature sensors, and other sensors, etc.

The electronic device may include power management circuitry and other input-output units 1322. The input-output units may include buttons, levers, click wheels, scroll wheels, touch pads, keypads, keyboards, cameras, light emitting diodes, and other status indicators, etc.

A user may control the operation of the electronic device by inputting commands through the input-output circuit 132, and may use the output data of the input-output circuit 132 to effect receipt of status information and other outputs from the electronic device.

The electronic device further comprises a charging circuit 133. The charging circuit 133 may charge the battery cells 14 of the electronic device. The charging circuit 133 may be used to further adjust the charging voltage and/or charging current input from the adapter to meet the charging requirements of the battery.

The electronic device is configured with a charging interface, which charging interface 123 may be, for example, a USB 2.0 interface, a Micro USB interface or a USB TYPE-C interface. In some embodiments, the charging interface may also be a lighting interface, or any other type of parallel or serial port that can be used for charging. The charging interface 400 is connected with an adapter through a data line, the adapter obtains electric energy from commercial power, and the electric energy is transmitted to a charging circuit through the data line transmission and the charging interface 400 after voltage conversion, so that the electric energy can be charged into a battery core to be charged through the charging circuit.

The following are embodiments of the disclosed method, corresponding to details not disclosed in the embodiments of the disclosed method, please refer to the embodiments of the disclosed apparatus. The battery in the following examples is a lithium ion battery.

Fig. 3 is a flowchart illustrating a charge control method according to an exemplary embodiment. The charging control method disclosed by the disclosure comprises the following steps:

step S20, acquiring the charging state of the battery cell, wherein the charging state is the battery cell voltage or the charging state of the battery cell;

Step S21, charging the battery core with the charging current corresponding to the charging state according to the pre-stored corresponding relation between the charging state and the charging current; the method for acquiring the corresponding relation between the pre-stored charging state and the charging current comprises the following steps: and adjusting the test charging current of the battery cell according to the monitored lithium precipitation state of the battery cell cathode, recording the corresponding test charging state, and taking the generated corresponding relation between the test charging state and the test charging current as the pre-stored corresponding relation between the charging state and the charging current.

In the charging process of the user in the using stage, the charging state can be detected at equal time intervals, and the charging state can also be detected randomly. Specifically, the step of acquiring the charging state of the battery cell in this embodiment includes:

acquiring the charging state of the battery cell at intervals of a first preset time length;

according to the pre-stored corresponding relation between the charging state and the charging current, charging the battery core with the charging current corresponding to the charging state comprises the following steps:

and in each first preset time period, charging the battery core with the charging current corresponding to the last acquired charging state of the battery core according to the corresponding relation between the pre-stored charging state and the charging current.

The first preset time period is not limited herein, and may be 1 second or 5 seconds. The method can be determined according to the working frequency of a charging circuit for charging the battery cells and actual requirements.

Taking the first preset time length as 1 second as an example, at the beginning time of the first 1 second when charging begins, the current charging state of the battery cell is obtained, and according to the corresponding relation between the pre-stored charging state and the charging current, the charging current corresponding to the current charging state is 4000mA, and then the battery cell is charged with 4000mA in 1 second. At the second 1 second starting time, the current charging state of the battery cell is obtained again, and at this time, the charging current corresponding to the current charging state is 4100mA, then the battery cell is charged with a constant current of 4100mA in the second 1 second, and at the third 1 second starting time.

In the charging process of the battery cell, the voltage of the battery cell increases along with the progress of charging, and the state of charge (the ratio of the remaining capacity to the capacity of the full charge state, SOC) of the battery cell also increases gradually. In this embodiment, the charging state may be a voltage of the battery cell or a charging state of the battery cell.

The memory unit of the electronic equipment is provided with a pre-stored corresponding relation between the charging state and the charging current. It can be understood that when the charging state of the battery cell is the battery cell voltage, the corresponding relationship between the pre-stored charging state and the charging current is the corresponding relationship between the pre-stored battery cell voltage and the charging current; when the charging state of the battery core is the charging state of the battery core, the corresponding relation between the pre-stored charging state and the charging current is correspondingly the corresponding relation between the pre-stored charging state of the battery core and the charging current.

In this embodiment, the corresponding relationship between the pre-stored battery cell voltage and the pre-stored charging current is obtained by performing the charging test on the battery cell in the laboratory stage, and the battery cell can be independent of the electronic device at this time, and the charging test system is used for performing the charging test independently. It should be noted that, since the mass-produced cells have substantially the same performance, it is not required that the cells used for the test in the laboratory be the same cells as those to be mounted in the electronic device, so long as both are the same specification, the same model, or the same lot of cells. The corresponding relation between the pre-stored battery cell voltage and the charging current can be represented in a curve form (as shown in fig. 5) or in a table form.

In the charging test of the battery cell, the test charging current of the battery cell is adjusted according to the monitored lithium precipitation state of the negative electrode of the battery cell, and the corresponding test charging state is recorded. This is because lithium ions are continuously intercalated from the positive electrode to the negative electrode of the battery cell during the charging process, but once the lithium ion intercalation rate at the surface of the negative electrode exceeds the bearing capacity of the negative electrode, lithium ions remain at the surface of the negative electrode and cannot be intercalated into the negative electrode. Along with the progress of charging, the electric potential on the surface of the negative electrode of the battery cell can be continuously reduced, and when the electric potential reaches the electric potential generated by lithium metal, a lithium metal simple substance can be generated, and the generated lithium metal simple substance can threaten the safety of the battery.

In an embodiment, the lithium-precipitating state of the negative electrode of the battery cell is monitored on line on the electronic device to guide the charging current, but this method is affected by the space in the electronic device and other internal components, and the detected lithium-precipitating state of the negative electrode has poor accuracy and stability, so that the charging current cannot be effectively guided. In this embodiment, the test charging current is adjusted on line in the laboratory according to the lithium-separating state of the negative electrode of the battery cell, so that sufficient resources can be provided to ensure the accuracy and stability of detection of the lithium-separating state of the negative electrode of the battery cell, and thus the charging current is effectively and accurately adjusted, and the on-line test is performed to obtain a better corresponding relation between the pre-stored charging state and the charging current.

In this embodiment, when the battery cell is subjected to the charging test in the laboratory stage, the charging current is guided by the lithium precipitation state of the negative electrode of the battery cell. Referring to fig. 4, specifically, the correspondence between the pre-stored charging state and the charging current is determined by the following steps:

step S30, acquiring a lithium precipitation state of the battery cell cathode every a second preset time period in the charging test process;

step S31, in each second preset time period, according to the lithium precipitation state of the negative electrode of the battery cell, the test charging current of the battery cell is adjusted, and the test charging state of the battery cell corresponding to the test charging current is recorded;

and step S32, generating and storing the corresponding relation between the test charging current and the battery cell test charging state.

The smaller the second preset duration is, the higher the acquisition frequency of the lithium-precipitating state of the battery cell cathode is, so that the timeliness and accuracy of monitoring the lithium-precipitating state of the battery cell cathode can be improved, the test charging current can be adjusted in time according to the lithium-precipitating state of the battery, and the optimal corresponding relation between the test charging current and the test charging state of the battery cell is obtained on the premise of ensuring the safety of the battery cell cathode. The second duration may be 0.5 seconds, 1 second, 2 seconds, etc.

And in the first second preset time period of the charging test, the test charging current is smaller than or equal to the rated charging current of the battery cell. For example, the capacity of the battery cell is 3000mAh, the rated multiplying power is 1.5C, namely the rated charging current is 4500mA, and at the moment, the battery cell can be charged with 4000mA in a constant current within a first second preset time period. This avoids some of the safety issues that may be caused by starting to charge the cells with a larger rated charge current when the performance of the battery is unknown.

In the process of the charging test, the lithium-separating state of the battery can be roughly divided into three states, namely a lithium-separating state, a non-lithium-separating state and a lithium-separating critical state, so that the test charging current can correspondingly have different adjustment schemes according to the three lithium-separating states. The method comprises the following steps:

aiming at the non-lithium-precipitation state, in each second preset time period, according to the lithium-precipitation state of the negative electrode of the battery cell, adjusting the test charging current of the battery cell comprises:

and in each second preset time period, when the lithium is not separated from the negative electrode of the battery cell, increasing the test charging current.

The test charging current increases in amplitude, which is equal to the first preset test charging current amplitude. For example, the first preset amplitude may be 100mA.

In another embodiment, the increase of the test charging current is correspondingly different according to the degree of non-lithium precipitation, and the greater the degree of non-lithium precipitation is, the greater the increase of the test charging current is, and the smaller the degree of non-lithium precipitation is, the closer the critical state of lithium precipitation is.

Aiming at the lithium precipitation state, in each second preset time period, according to the lithium precipitation state of the negative electrode of the battery cell, adjusting the test charging current of the battery cell comprises:

and in each second preset time period, when lithium is separated from the cathode of the battery cell, reducing the test charging current.

And when lithium precipitation does not occur at the negative electrode of the battery cell, the reduced amplitude of the test charging current is the second preset test charging current amplitude. The second preset amplitude value can be larger than or equal to the first preset amplitude value, so that when lithium precipitation occurs to the negative electrode of the battery cell, the charging current can be rapidly reduced, the lithium precipitation degree is prevented from being further increased, and the safety of the battery cell is ensured. For example, the second preset amplitude may be 100mA.

In another embodiment, according to different lithium precipitation degrees, the reduction amplitude of the test charging current is correspondingly different, the larger the lithium precipitation degree is, the larger the reduction amplitude of the test charging current is correspondingly, and the reduction amplitude of the test charging current is gradually reduced along with the fact that the lithium precipitation degree is closer to a lithium precipitation critical state, so that the influence on the charging speed caused by excessive reduction of the test charging current is avoided.

Aiming at the lithium precipitation critical state, in each second preset time period, according to the lithium precipitation state of the negative electrode of the battery cell, adjusting the test charging current of the battery cell comprises:

and in each second preset time period, when the negative electrode of the battery cell is in a critical state of lithium precipitation, maintaining the test charging current.

When the lithium ion battery is in a lithium ion battery critical state, the current test charging current can be kept unchanged, and the balance of the charging speed and the lithium ion battery state is achieved.

As illustrated herein, the cell lithium out state is detected once every second during the charge test. In the first second, the battery cell is charged with 4000mA in a constant current manner, when the second is started, the battery cell is charged with 100mA in an amplified manner, namely 4100mA in the second, when the third second is started, the battery cell is charged with 4200mA in a constant current manner, and when the third second is started, the battery cell is charged with 100mA in an amplified manner; when the fourth second starts, detecting that a lithium precipitation critical state occurs, and keeping the current 4200mA to charge the battery cell at constant current in the fourth second; at the beginning of the fifth second, the occurrence of the lithium-out state is detected, and the cell is charged … … with a constant current for the fifth second at 100mA in a step-down manner, that is, at 4100 mA.

In addition, unlike on-line monitoring of the lithium-out state of the battery cell negative electrode on the electronic device, the pre-stored correspondence between the charging state and the charging current is measured on line in a laboratory, so that sufficient resources can be provided to ensure the detection accuracy and stability of the lithium-out state of the battery cell negative electrode, a better pre-stored correspondence between the charging state and the charging current can be obtained, the subsequent charging process is guided according to the correspondence, and the purposes of taking the battery cell charging safety into consideration, preventing the occurrence of lithium-out of the negative electrode, ensuring the use safety of the battery cell, slowing down the aging speed of the negative electrode and the like can be achieved.

Therefore, the embodiment can reliably realize the quick charging of the battery cell and ensure the charging safety of the battery cell.

Referring to fig. 6, in this embodiment, further consideration is given to the fact that the battery cells age with the increase of the charging times, so that the corresponding relationship between the charging state and the charging current, which are pre-stored in the prior art, cannot well guide the charging of the battery cells with changed performance. Therefore, in this embodiment, the following steps are executed at least once before the step of charging the battery cell with the charging current corresponding to the charging state according to the pre-stored correspondence between the charging state and the charging current:

Acquiring stored charged times of the battery cell, and updating the stored charged times of the battery cell;

determining a corresponding relation between a first pre-stored charging state and charging current, which is matched with the charged times of the battery cell, from the corresponding relation between a plurality of pre-stored charging states and charging currents;

according to the pre-stored corresponding relation between the charging state and the charging current, the step of charging the battery core by the charging current corresponding to the charging state is as follows:

and charging the battery core with the charging current corresponding to the charging state according to the corresponding relation between the first pre-stored charging state and the charging current.

Correspondingly, in the laboratory stage, according to the gradual increase of the charging times of the battery cell, the corresponding relation between the test charging state and the test charging current is tested. The following steps are executed at least once before the step of acquiring the lithium-separating state of the negative electrode of the battery cell at intervals of a second preset time length:

the generation and storage of the corresponding relation between the test charging current and the battery cell test charging state comprises the following steps:

when the charged times of the battery cell reach the preset charged times, generating a corresponding relation between the test charging current and the test charging state of the battery cell, and storing the corresponding relation between the charged times of the battery cell and the test charging state of the battery cell in a correlated way.

In this embodiment, in the laboratory stage, when the battery cell is subjected to the charging test in advance, consideration of the number of times of charging is added. Each charging is performed by adjusting the test charging current of the battery cell according to the lithium precipitation state of the negative electrode of the battery cell in the embodiment; and determining whether to generate and store the corresponding relation between the test charging current and the test charging state of the battery cell according to the preset charged times of the battery cell.

For example, only the correspondence between the test charge state and the test charge current measured at the 1 st, 300 rd, and 600 th times (of course, not limited thereto) is generated and stored, and this correspondence is correlated with the number of times of charging. Referring to fig. 5, the dashed line is a corresponding relationship curve between the test charging state and the test charging current measured 300 times, and the solid line is a corresponding relationship curve between the test charging state and the test charging current measured for the first time. It can be seen that as the number of times of battery charging increases, the performance of the battery cell changes, and the corresponding relationship between the test charging state and the test charging current measured at 300 times and 1 st time is different.

And in the using stage of the user, recording the charged times of the battery cell. Specifically, when each charging is started, the charged times of the battery cell can be obtained first, and the charged times are added with 1 to be used as the current charged times of the battery cell. And then, according to the current charged times of the battery cell, calling the corresponding relation between the adaptive pre-stored charging state and the charging current.

For example, when the number of times the battery cell has been charged is 150, the corresponding relationship between the test charging state measured at the 1 st time in the laboratory stage and the test charging current is called; when the charged times of the battery cell are 360 times, the corresponding relation between the test charging state measured at the 300 th time in the laboratory stage and the test charging current is called at the moment; when the number of times the battery cell has been charged is 700, the corresponding relationship … … between the test charging state measured at the 600 th time in the laboratory stage and the test charging current is called.

In another embodiment, in order to make the correspondence between the charging current and the invoked pre-stored charging state and the charging current have a higher matching property in the user use stage, the correspondence between the test charging state and the test charging current may be densely tested in the laboratory stage for the number of times the battery cell has been charged. Specifically, in the charging test process, the following steps are executed at least once before the step of obtaining the lithium precipitation state of the negative electrode of the battery cell every second preset time interval:

the generating of the corresponding relation between the test charging current and the battery cell test charging state comprises the following steps:

And generating a corresponding relation between the test charging current and the test charging state of the battery cell, and storing the corresponding relation between the charged times of the battery cell and the test charging state of the battery cell in a correlation way.

In this embodiment, after each charge in the laboratory phase, a correspondence of the test charge current to the test state of charge of the cell is generated.

The embodiment further considers that the battery core is aged along with the increase of the charging times, so that the corresponding relation between the original pre-stored charging state and the charging current cannot well guide the charging of the battery core with changed performance. Therefore, the corresponding relation between the charged times of the battery cells and the test charging current and the test charging state of the battery cells is stored in a correlation manner in a laboratory stage, and in a user use stage, the corresponding relation between the pre-stored charging state and the charging current which are adapted can be called according to the charged times of the battery cells, so that the effects of quick charging and charging safety of the battery cells are ensured.

In this embodiment, a method for accurately determining a lithium precipitation state of a negative electrode of a battery cell is provided, where the lithium precipitation state of the negative electrode of the battery cell is determined by:

preparing a reference electrode 141 on the cell;

Acquiring a difference value between the voltage of the reference electrode 141 and the voltage of the negative electrode of the battery cell;

comparing the difference between the voltage of the reference electrode 141 and the voltage of the negative electrode of the battery cell with a first preset voltage difference;

when the difference between the voltage of the reference electrode 141 and the voltage of the negative electrode of the battery cell is larger than the first preset voltage difference, lithium is separated from the corresponding negative electrode of the battery cell; when the difference between the voltage of the reference electrode 141 and the voltage of the negative electrode of the battery cell is smaller than the first preset voltage difference, no lithium precipitation occurs to the corresponding negative electrode of the battery cell; when the difference between the voltage of the reference electrode 141 and the voltage of the negative electrode of the battery cell is equal to the first preset voltage difference, the corresponding negative electrode of the battery cell is in a lithium separation critical state.

The reference electrode 141 may be a metal lithium electrode, a lithium-plated copper wire electrode (which may be a copper wire built-in and then plated with lithium), a lithium metal alloy electrode, a lithium titanate electrode, or the like.

A stable reference electrode 141 is embedded in the cell; in the charging process of the laboratory test stage, the potential change of the cell negative electrode relative to the reference electrode 141 is monitored, and the lithium precipitation state of the cell negative electrode can be judged. The first preset voltage difference may be 0V, and may be higher, for example, 10mV, in consideration of polarization of the battery cells. Generally, the first preset voltage difference is 0V to 20mV.

The lithium precipitation state of the negative electrode is detected by disassembling the battery cell, so that the environment requirement is high, and the charging current of the battery cell cannot be controlled in real time on line. And the lithium precipitation state of the negative electrode is judged by the change of the static voltage after the charging is finished, and only the lithium precipitation state corresponding to a certain voltage point can be judged. Judging whether the lithium-precipitating state of the negative electrode is not excluded from the aging condition of the battery or even erroneous judgment is possible by the value of dQ/dV (the ratio of the rate of change of the electric quantity to the voltage). In the scheme of judging the lithium precipitation state of the negative electrode in a model calculation mode, calculation about the model is very complex, feedback is not timely, and in addition, the error of the model calculation is not guaranteed.

Therefore, the technical scheme of the embodiment is to monitor the difference between the voltage of the reference electrode 141 and the voltage of the negative electrode of the battery cell in the laboratory stage to determine the lithium precipitation state of the negative electrode of the battery cell, and to adjust the charging current of the battery cell on line in real time according to the fed back lithium precipitation state of the negative electrode of the battery cell, so as to reduce the occurrence of lithium precipitation phenomenon of the negative electrode of the battery cell, and to maximize the charging current to ensure the charging speed on the premise of ensuring the charging safety of the battery cell.

Referring to fig. 8, the present disclosure further provides a charging control device 50, including: an obtaining unit 51, configured to obtain a charging state of the battery cell, where the charging state is a battery cell voltage or a charging state of the battery cell; the adjusting unit 52 is configured to charge the battery cell with a charging current corresponding to the charging state according to a pre-stored correspondence between the charging state and the charging current; the pre-stored corresponding relation between the charging state and the charging current is that the test charging current of the battery cell is adjusted according to the monitored lithium precipitation state of the negative electrode of the battery cell, and the corresponding test charging state is recorded so as to generate the corresponding relation between the test charging state and the test charging current.

In an embodiment, the obtaining unit 51 is configured to obtain a charging state of the battery cell every a first preset duration;

the adjusting unit 52 is configured to charge the battery cell with a charging current corresponding to the last acquired charging state of the battery cell according to a pre-stored correspondence between the charging state and the charging current within each first preset period.

The obtaining unit 51 is further configured to obtain the stored number of times the battery cell has been charged, and update the stored number of times the battery cell has been charged;

the matching unit is used for determining the corresponding relation between the first pre-stored charging state and the charging current, which is matched with the charged times of the battery cell, from the corresponding relation between the plurality of pre-stored charging states and the charging current;

Reference may be made to the above-described method item embodiments for specific embodiments of the charge control device 50 of the present disclosure.

The electronic equipment provided by the disclosure comprises a battery cell, a charging circuit, a storage unit and a processing unit; the storage unit is used for storing a charging control program; the processing unit is used for running a charging control program, and when the charging control program is executed, the charging control method is operated so as to control the charging circuit to charge the battery cell.

Referring to fig. 7, the electronic device is in the form of a general purpose computing device. Components of an electronic device may include, but are not limited to: the at least one processing unit 42, the at least one memory unit 41, and the bus 43 connecting the different system components (including the memory unit 420 and the processing unit 410), wherein the memory unit 41 stores program code that can be executed by the processing unit 42 such that the processing unit 42 performs the steps described in the above-described examples section of the present disclosure according to various exemplary embodiments of the present disclosure.

The storage unit 41 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 411 and/or a cache memory unit 412, and may further include a read only memory unit (ROM) 413.

The storage unit 41 may also include a program/utility 414 having a set (at least one) of program modules 415, such program modules 415 including, but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of which may include an implementation of a network environment.

The bus 43 may be one or more of several types of bus structures including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

The electronic device 4 may also communicate with one or more external devices 50 (e.g., keyboard, pointing device, bluetooth device, etc.), one or more devices that enable a user to interact with the electronic device 4, and/or any device (e.g., router, modem, display unit 44, etc.) that enables the electronic device 4 of the robot to communicate with one or more other computing devices. Such communication may be through an input/output (I/O) interface 45. And, the electronic device 4 of the robot may also communicate with one or more networks, such as a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network, such as the internet, through a network adapter 46. As shown in fig. 7, the network adapter 46 communicates with other modules of the electronic device 4 of the robot via the bus 43. It should be appreciated that although not shown in fig. 7, other hardware and/or software modules may be used in connection with the electronic device 4 of the robot, including, but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, data backup storage systems, and the like.

From the above description of embodiments, those skilled in the art will readily appreciate that the example embodiments described herein may be implemented in software, or may be implemented in software in combination with the necessary hardware. Thus, the technical solution according to the embodiments of the present disclosure may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (may be a CD-ROM, a U-disk, a mobile hard disk, etc.) or on a network, including several instructions to cause a computing device (may be a personal computer, a server, a terminal device, or a network device, etc.) to perform the method according to the embodiments of the present disclosure.

In an exemplary embodiment of the present disclosure, a computer-readable storage medium having stored thereon a program product capable of implementing the method described above in the present specification is also provided. In some possible implementations, various aspects of the disclosure may also be implemented in the form of a program product comprising program code for causing a terminal device to carry out the steps according to the various exemplary embodiments of the disclosure as described in the foregoing examples section of this specification, when the program product is run on the terminal device.

The disclosure further provides a charging test system for performing a charging test on the battery cell in a laboratory stage to generate the pre-stored correspondence between the charging state and the charging current. Referring to fig. 9, the battery cell has a positive electrode, a negative electrode and a reference electrode 141, and the charging test system includes a voltage detection device 62 and a charging device 61. The voltage detection device 62 has two input ends and an output end, the two input ends of the voltage detection device 62 are respectively connected with the cathode of the power core and the reference electrode 141, the potential of the reference electrode 141 is the ground potential of the voltage detection device 62, and the output end of the voltage detection device 62 is used for outputting the cathode voltage of the power core; the charging device 61 has a signal receiving end and a charging end, the signal receiving end is connected with the output end of the voltage detecting device 62, the charging end is connected with the positive pole and the negative pole of the battery cell, and the potential of the negative pole voltage is the ground potential of the charging device 61; the charging device 61 adjusts the test charging current to the battery cell according to the negative electrode voltage detected by the voltage detecting device 62.

In another embodiment, in order to improve the accuracy of the voltage of the negative electrode of the battery cell measured by the voltage detection device 62, a positive electrode of the battery cell is also connected to the voltage detection device 62.

In this embodiment, since the ground potential of the voltage detection device 62 is different from the ground potential of the charging device 61, specifically, the ground potential of the voltage detection device 62 is the negative potential of the reference electrode 141, and the ground potential of the charging device 61 is the negative potential of the battery cell, the voltage signal output from the voltage detection device 62 to the charging device 61 is the difference between the negative potential of the battery cell and the reference potential.

In one embodiment, when the voltage value obtained by the charging device 61 is 0, that is, the difference between the potential of the negative electrode of the battery cell and the reference potential is 0V, the negative electrode of the battery cell is in a lithium separation critical state; when the voltage value obtained by the charging device 61 is greater than 0V, that is, the difference between the potential of the negative electrode of the battery cell and the reference potential is greater than 0, the negative electrode of the battery cell is in a state of not precipitating lithium; when the voltage value obtained by the charging device 61 is smaller than 0, that is, the difference between the potential of the negative electrode of the battery cell and the reference potential is smaller than 0V, the negative electrode of the battery cell is in a lithium precipitation state.

It will be appreciated that by setting a value higher than 0V instead of 0V in the above embodiment, the lithium-out state limit of the cell negative electrode is set.

In the present embodiment, the signal receiving end of the charging device 61 and the output end of the voltage detecting device 62 pass through I ² The C bus or the system management bus is in communication connection.

In one embodiment, the voltage detecting device 62 includes a sampling circuit and an analog-to-digital conversion circuit that are connected, where the sampling circuit is used to collect the negative voltage of the current core and transmit the negative voltage to the analog-to-digital conversion circuit, and the negative voltage is output to the charging device 61 after passing through the analog-to-digital conversion circuit; the ground of the sampling circuit and the ground of the analog-to-digital conversion circuit are both connected to the reference electrode 141. The sampling circuit can be built by a sampling resistor and a reference power supply. The analog-to-digital conversion circuit may be an analog-to-digital conversion chip.

In another embodiment, the voltage detecting device 62 includes a sampling circuit and a controller, the sampling circuit is used for sampling the negative voltage of the current core and transmitting the negative voltage to the controller, and the controller transmits a digital signal corresponding to the negative voltage to the charging device 61; the ground of the sampling circuit and the ground of the controller are both connected to a reference electrode 141. The controller can be a control chip with digital logic processing function such as MCU, CPU, etc.

The charging device 61 has a charging circuit, a memory, and a controller; the memory stores a stored charging test program; and the processor runs a charging control program and a charging test method which runs when the charging test program is executed.

According to the charging test system, the voltage detection device 62 is in communication connection with the charging device 61, so that the lithium-precipitation state of the negative electrode of the battery cell is fed back to the voltage detection device 62, the voltage detection device 62 is used for adjusting the charging current, closed-loop control of the charging current is formed, the corresponding relation between the test charging state generated by the test and the test charging current reflects the corresponding relation between the charging state and the charging current on the premise of considering the charging safety of the battery cell and preventing the lithium-precipitation of the negative electrode, and therefore the subsequent charging process is guided according to the corresponding relation, and the purposes of considering the charging safety of the battery cell, preventing the lithium-precipitation of the negative electrode and guaranteeing the use safety of the battery cell can be achieved.

The present disclosure further provides a charging test method, referring to fig. 10, the method includes:

step S70, acquiring the negative voltage of the battery cell and the reference electrode 141 every third preset time period, and confirming the lithium precipitation state of the battery cell according to the negative voltage of the battery cell;

step S71, in each third preset time period, according to the lithium precipitation state of the negative electrode of the battery cell, adjusting the test charging current of the battery cell, and recording the test charging state of the battery cell corresponding to the test charging current;

And step S72, generating a corresponding relation between the test charging current and the battery cell test charging state.

The smaller the third preset duration is, the higher the acquisition frequency of the lithium-out state of the battery cell negative electrode is, so that the timeliness and the accuracy of monitoring the lithium-out state of the battery cell negative electrode can be improved, the test charging current can be adjusted in time according to the lithium-out state of the battery, and the optimal corresponding relation between the test charging current and the test charging state of the battery cell is obtained on the premise of ensuring the safety of the battery cell negative electrode. The second duration may be 0.5 seconds, 1 second, 2 seconds, etc.

And in the first third preset time period of the charging test, the test charging current is smaller than or equal to the rated charging current of the battery cell. For example, the capacity of the battery cell is 3000mAh, the rated multiplying power is 1.5C, namely the rated charging current is 4500mA, and at the moment, the battery cell can be charged with 4000mA in a constant current within a first third preset time period. This avoids some of the safety issues that may be caused by starting to charge the cells with a larger rated charge current when the performance of the battery is unknown.

Aiming at the state of non-lithium precipitation, in each third preset time period, according to the state of lithium precipitation of the negative electrode of the battery cell, adjusting the test charging current of the battery cell comprises:

and in each third preset time period, when the lithium is not separated from the negative electrode of the battery cell, increasing the test charging current.

and in each third preset time period, when lithium is separated from the negative electrode of the battery cell, reducing the test charging current.

And when lithium precipitation does not occur at the negative electrode of the battery cell, the reduced amplitude of the test charging current is a third preset test charging current amplitude. The third preset amplitude value can be larger than or equal to the first preset amplitude value, so that when lithium precipitation occurs to the negative electrode of the battery cell, the charging current can be rapidly reduced, the lithium precipitation degree is prevented from being further increased, and the safety of the battery cell is ensured. For example, the third preset amplitude may be 100mA.

Aiming at the lithium precipitation critical state, in each third preset time period, according to the lithium precipitation state of the negative electrode of the battery cell, adjusting the test charging current of the battery cell comprises:

and in each third preset time period, when the negative electrode of the battery cell is in a critical state of lithium precipitation, maintaining the test charging current.

The embodiment further considers that the battery core is aged along with the increase of the charging times, so that the corresponding relation between the original pre-stored charging state and the charging current cannot well guide the charging of the battery core with changed performance. Therefore, in this embodiment, the following steps are executed at least once before the step of charging the battery cell with the charging current corresponding to the charging state according to the pre-stored correspondence between the charging state and the charging current:

Correspondingly, in the laboratory stage, according to the gradual increase of the charging times of the battery cell, the corresponding relation between the test charging state and the test charging current is tested. The following steps are executed at least once before the step of acquiring the lithium-separating state of the negative electrode of the battery cell at intervals of a third preset time length:

For example, only the correspondence between the test charge state and the test charge current measured at the 1 st, 300 rd, and 600 th times (of course, not limited thereto) is generated and stored, and this correspondence is correlated with the number of times of charging. Referring to the figure, it can be seen that, as the number of times of charging the battery increases, the performance of the battery cell changes, and the corresponding relationship between the test charging state and the test charging current measured at 300 times and 1 st time is different.

While the invention has been described with reference to several exemplary embodiments, it is to be understood that the terminology used is intended to be in the nature of words of description and of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

1. A charging control method, characterized by comprising:

charging the battery cell with the charging current corresponding to the charging state according to the pre-stored corresponding relation between the charging state and the charging current;

the method for acquiring the corresponding relation between the pre-stored charging state and the charging current comprises the following steps: adjusting the test charging current of the battery cell according to the monitored lithium precipitation state of the battery cell cathode, recording the corresponding test charging state, taking the corresponding relation between the generated test charging state and the test charging current as the corresponding relation between the pre-stored charging state and the charging current, and

The lithium precipitation state of the battery cell cathode is determined by the following steps:

preparing a reference electrode on the cell;

obtaining a difference value between the voltage of the reference electrode and the voltage of the negative electrode of the battery cell;

comparing the difference value between the voltage of the reference electrode and the voltage of the negative electrode of the battery cell with a first preset voltage difference value;

when the difference between the voltage of the reference electrode and the voltage of the negative electrode of the battery cell is larger than the first preset voltage difference, lithium is separated from the corresponding negative electrode of the battery cell; when the difference value between the voltage of the reference electrode and the voltage of the negative electrode of the battery cell is smaller than the first preset voltage difference value, no lithium precipitation occurs to the corresponding negative electrode of the battery cell; when the difference value between the voltage of the reference electrode and the voltage of the negative electrode of the battery cell is equal to the first preset voltage difference value, the corresponding negative electrode of the battery cell is in a lithium precipitation critical state,

wherein, the adjustment of the test charging current of the battery cell comprises at least one of the following:

when lithium is not separated from the negative electrode of the battery cell, increasing the test charging current;

when lithium is separated from the negative electrode of the battery cell, the test charging current is reduced;

and when the battery cell cathode is in a critical state of lithium precipitation, maintaining the test charging current.

2. The charge control method according to claim 1, wherein the step of acquiring the state of charge of the battery cell includes:

according to the corresponding relation between the pre-stored charging state and the charging current, the charging the battery cell with the charging current corresponding to the charging state comprises:

and in each first preset time period, charging the battery cell with the charging current corresponding to the last acquired charging state of the battery cell according to the corresponding relation between the pre-stored charging state and the charging current.

3. The charge control method according to claim 1, wherein the step of charging the battery cell with the charging current corresponding to the charging state is performed at least once before the step of charging the battery cell with the charging current corresponding to the charging state according to a pre-stored correspondence relation between the charging state and the charging current:

determining the corresponding relation between the first pre-stored charging state and the charging current, which is matched with the charged times of the battery cell, from the corresponding relation between the plurality of pre-stored charging states and the charging current;

the step of charging the battery cell with the charging current corresponding to the charging state according to the corresponding relation between the pre-stored charging state and the charging current comprises the following steps:

And charging the battery cell with the charging current corresponding to the charging state according to the corresponding relation between the first pre-stored charging state and the charging current.

4. The charge control method according to claim 1, wherein the step of acquiring the correspondence between the pre-stored charge state and the charge current is:

in the charging test process, acquiring the lithium precipitation state of the negative electrode of the battery cell every second preset time period;

in each second preset time period, according to the lithium precipitation state of the negative electrode of the battery cell, adjusting the test charging current of the battery cell, and recording the test charging state of the battery cell corresponding to the test charging current;

and generating and storing the corresponding relation between the test charging current and the battery cell test charging state.

5. The method of claim 4, wherein the test charging current is less than or equal to the rated charging current of the battery cell for a first second predetermined duration of a charging test.

6. The method according to claim 4, wherein said adjusting the test charging current of the battery cell according to the lithium precipitation state of the negative electrode of the battery cell within each of the second preset time periods comprises:

7. The charge control method of claim 6, wherein the magnitude of the increase in the test charging current is the first predetermined test charging current magnitude when no lithium precipitation occurs at the cell negative electrode.

8. The method according to claim 4, wherein said adjusting the test charging current of the battery cell according to the lithium precipitation state of the battery cell negative electrode in each second preset time period comprises:

and in each second preset time period, when lithium is separated from the negative electrode of the battery cell, reducing the test charging current.

9. The charge control method of claim 8, wherein the magnitude of the test charge current decrease is a second predetermined test charge current magnitude when no lithium precipitation occurs at the cell negative electrode.

10. The method according to claim 4, wherein said adjusting the test charging current of the battery cell according to the lithium precipitation state of the negative electrode of the battery cell within each of the second preset time periods comprises:

And in each second preset time period, when the battery cell negative electrode is in a critical state of lithium precipitation, maintaining the test charging current.

11. The method according to claim 4, wherein the step of obtaining the lithium-out state of the negative electrode of the battery cell every second preset time period during the charging test is performed at least once, by the following steps:

the generating and storing the corresponding relation between the test charging current and the battery cell test charging state comprises the following steps:

12. The charge control method according to claim 4, wherein the step of obtaining the lithium-out state of the cell negative electrode every second preset time period during the charge test is performed at least once before the step of obtaining the lithium-out state of the cell negative electrode every second preset time period:

The corresponding relation between the generated test charging current and the battery cell test charging state comprises the following steps:

and generating a corresponding relation between the test charging current and the test charging state of the battery cell, and storing the corresponding relation between the charged times of the battery cell and the test charging state of the battery cell in a correlated way.

13. The charge control method according to claim 1, wherein the first preset voltage difference is 0V to 20mV.

14. A charge control device, characterized by comprising:

preparing a reference electrode on the cell;

15. An electronic device is characterized by comprising a battery cell, a charging circuit, a storage unit and a processing unit;

the storage unit is used for storing a charging control program;

the processing unit is configured to execute a charging control program, and when the charging control program is executed, the charging control method according to any one of claims 1 to 13 is executed to control the charging circuit to charge the battery cell.

16. A charge test system for performing a charge test on a cell having a positive electrode, a negative electrode, and a reference electrode, the charge test system comprising:

the charging device is provided with a signal receiving end and a charging end, the signal receiving end is connected with the output end of the voltage detection device, the charging end is connected with the anode and the cathode of the battery cell, and the potential of the voltage of the cathode is the ground potential of the charging device; the charging device confirms the lithium precipitation state of the battery cell according to the difference value of the negative electrode voltage and the reference electrode voltage detected by the voltage detection device so as to adjust the test charging current of the battery cell,

preparing a reference electrode on the cell;

17. The charge test system of claim 16, wherein the signal receiving end of the charging device and the output end of the voltage detection device pass through I ² The C bus or the system management bus is in communication connection.

18. The charging test system according to claim 16, wherein the voltage detection device comprises a sampling circuit and an analog-to-digital conversion circuit which are connected, the sampling circuit is used for collecting a negative voltage of the battery cell and transmitting the negative voltage to the analog-to-digital conversion circuit, and the negative voltage is output to the charging device after passing through the analog-to-digital conversion circuit;

the grounding end of the sampling circuit and the grounding end of the analog-to-digital conversion circuit are both connected with the reference electrode.

19. The charge test system of claim 16, wherein the voltage detection device comprises a sampling circuit and a controller, the sampling circuit is used for collecting a negative voltage of the battery cell and transmitting the negative voltage to the controller, and the controller transmits a digital signal corresponding to the negative voltage to the charging device;

and the grounding end of the sampling circuit and the grounding end of the controller are both connected with the reference electrode.

20. A method of charging testing, the method comprising:

Obtaining the difference value between the negative electrode voltage and the reference electrode voltage of the battery cell every third preset time period to confirm the lithium precipitation state of the battery cell;

generating a corresponding relation between the test charging current and the battery cell test charging state,

preparing a reference electrode on the cell;

21. The method of claim 20, wherein the test charging current is less than or equal to the rated charging current of the battery cell for a first third predetermined duration of the charging test.

22. The method according to claim 20, wherein adjusting the test charging current of the battery cell according to the lithium precipitation state of the negative electrode of the battery cell in each of the third preset time periods comprises:

23. The method according to claim 20, wherein adjusting the test charging current of the battery cell according to the lithium precipitation state of the negative electrode of the battery cell in each of the third preset time periods comprises:

24. The method according to claim 20, wherein adjusting the test charging current of the battery cell according to the lithium precipitation state of the negative electrode of the battery cell in each of the third preset time periods comprises:

and in each third preset time period, when the battery cell negative electrode is in a critical state of lithium precipitation, maintaining the test charging current.

25. The method according to claim 20, wherein the step of obtaining the lithium-out state of the negative electrode of the battery cell at intervals of a third preset time period during the charging process is performed at least once, by:

26. The method according to claim 20, wherein the step of obtaining the lithium-out state of the negative electrode of the battery cell at intervals of a third preset time period during the charging process is performed at least once, by:

27. A readable storage medium, comprising:

a memory storing a charge control program;

a processor that executes a charge control program that, when executed, executes the charge control method according to any one of claims 1 to 13.

28. A readable storage medium, comprising:

a memory storing a charge test program;

a processor running a charge control program which, when executed, runs a charge test method as claimed in any one of claims 20 to 26.