WO2021189319A1

WO2021189319A1 - Charging method, electronic device, and storage medium

Info

Publication number: WO2021189319A1
Application number: PCT/CN2020/081186
Authority: WO
Inventors: 张涵翔
Original assignee: 宁德新能源科技有限公司
Priority date: 2020-03-25
Filing date: 2020-03-25
Publication date: 2021-09-30
Also published as: CN113316878A

Abstract

Provided in the present application are a method for charging a battery. The method comprises: in a first phase, charging a battery per a first charging scheme or a second charging scheme to a first-phase voltage; in a second phase, charging the battery per a third charging scheme to a second-phase voltage, the second-phase voltage being greater than the first-phase voltage, where the third charging scheme employs the first charging scheme or the second charging scheme. Also provided in the present application are an electronic device and a storage medium. The charging speed in the process of charging the battery can be increased per the charging method provided in the present application, thus reducing the total charging time.

Description

Charging method, electronic device and storage medium

Technical field

This application relates to the field of battery technology, and in particular to a method for charging a battery, an electronic device, and a storage medium.

Background technique

The charging method commonly used now is the constant current and constant voltage charging method, that is, constant current charging to the charging limit voltage, and then constant voltage charging at the charging limit voltage, where the charging limit voltage refers to the conversion of the battery from constant current charging to constant voltage charging The maximum voltage value at the time, or the limit voltage written on the battery product package. The constant current and constant voltage charging method is used because the battery is polarized during the charging process, and the greater the current, the more obvious the polarization. When the constant current charging reaches the charging limit voltage, the battery cell is not fully charged due to polarization, so it is necessary to continue constant voltage charging. In the constant current phase, the charging current window is different because the battery is in different states of charge. In the existing charging method, basically one step is constant current charging to the cut-off voltage, and then constant voltage charging, which fails to effectively utilize the current windows of different states of charge in the constant current stage. And when the charging current of the battery is too large in the constant current charging process, there will be a risk of lithium evolution, and when the charging current is too small, the charging speed is too slow.

Summary of the invention

In view of this, it is necessary to provide a charging method, an electronic device and a storage medium, which can not only ensure the cycle life of the battery, but also shorten the total charging time of the battery.

An embodiment of the present application provides a battery charging method. The charging method includes a first stage and a second stage. In the first stage, the battery is charged to the first stage voltage in the first charging mode or the second charging mode. The first charging mode includes N charging sub-phases in sequence, where N is an integer greater than or equal to 2. The N charging sub-phases are defined as the i-th charging sub-phases, i=2, 3,..., N In the i-th charging sub-phase, charge the battery with one of the i-th current, the i-th voltage and the i-th power; in the i+1-th charging sub-phase, use the i+1-th current , One of the i+1th voltage and the i+1th power charges the battery; wherein the charging current of the battery in the i+1th charging sub-phase is less than or equal to The charging current during the charging sub-phase. The second charging method includes M charging sub-phases in sequence, M is an integer greater than or equal to 2, the M charging sub-phases are defined as the j-th charging sub-phase, j = 1, 2, ..., M , And each of the j-th charging sub-stage includes a j-th pre-charge sub-stage and a j-th post-charge sub-stage; in one of the j-th pre-charge sub-stage and the j-th post-charge sub-stage, The battery is not charged or is charged or discharged with the j-th pre-charge sub-current for Tj1; in the other of the j-th pre-charge sub-stage and the j-th post-charge sub-stage, the battery is The j-th post-charger current is charged for a duration of Tj2; wherein the absolute value of the j-th pre-charger current is smaller than the absolute value of the j-th post-charger current. In the second stage, the battery is charged to the second stage voltage in a third charging mode, and the second stage voltage is greater than the first stage voltage, and the third charging method adopts the first charging method or the The second charging method.

According to some embodiments of the present application, when the third charging method adopts the first charging method, the number of charging sub-stages N between the two is the same.

According to some embodiments of the present application, when the third charging method adopts the second charging method, the number of charging sub-stages M between the two is the same.

According to some embodiments of the present application, the (i+1)th voltage is greater than or equal to the (i)th voltage.

According to some implementation manners of the present application, the (i+1)th power is less than or equal to the (i)th power.

According to some embodiments of the present application, the average value of the charging current of the j+1th charging substage is less than or equal to the charging current of the jth substage, and when the third charging method adopts the second charging method , The average value of the charging current in the jth charging substage is smaller than the charging current in the first charging mode or the second charging mode.

According to some embodiments of the present application, the first stage voltage is equal to the charge limit voltage of the battery, and the second stage voltage is less than the oxidative decomposition voltage of the electrolyte in the battery.

According to some embodiments of the present application, the second stage voltage is less than or equal to the first stage voltage plus 500 millivolts.

According to some embodiments of the present application, the method further includes: in the third stage, performing constant voltage charging on the battery with the second stage voltage.

According to some embodiments of the present application, the charging current in the third charging mode is less than or equal to the charging current in the first charging mode or the second charging mode.

An embodiment of the present application provides an electronic device. The electronic device includes a battery and a processor, and the processor is configured to execute the charging method described above.

An embodiment of the present application provides a storage medium on which at least one computer instruction is stored, and the computer instruction is loaded by a processor and used to execute the battery charging method described above.

The embodiment of the present application is charged to the first stage voltage by at least one of constant current, constant voltage or constant power in the first stage; and in the second stage with constant current, constant voltage or constant power. At least one way to charge. Alternatively, the charging method of pulse charging or pulse charging and discharging may also be used in the first stage and the second stage. The charging method of the present application can optimize the early stage (first stage) of battery charging to reduce the conventional charging time in the early stage, reduce the risk of lithium evolution, shorten the cathode high potential time, thereby improving the cycle life of the battery cell and increasing the charging speed. In addition, the charging limit voltage of the battery is increased from the first stage voltage to the second stage voltage, so that the charging speed of the battery during the charging process can be increased, and the total charging time can be shortened.

Description of the drawings

FIG. 1 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Fig. 2 is a flowchart of a battery charging method according to an embodiment of the present application.

Fig. 3 is a diagram of the corresponding relationship between voltage and current during charging of a battery according to an embodiment of the present application.

FIG. 4 is a schematic diagram of the current and voltage changes with time during the charging process of the battery according to the first embodiment of the present application.

FIG. 5 is a schematic diagram of the current and voltage changes with time during the charging process of the battery according to the second embodiment of the present application.

Fig. 6 is a schematic diagram of power and voltage changes with time in the first stage, and current and voltage changes with time in the second stage according to an embodiment of the present application.

FIG. 7 is a schematic diagram of the current and voltage changes with time during the charging process of the battery according to the third embodiment of the present application.

FIG. 8 is a schematic diagram of the current and voltage changes with time during the charging process of the battery according to the fourth embodiment of the present application.

Fig. 9 is a block diagram of a charging system according to an embodiment of the present application.

Symbol description of main components

Electronic device 1

Charging system 10

Processor 11

Battery 12

The first charging module 101

Second charging module 102

The third charging module 103

The following specific embodiments will further describe this application in detail in conjunction with the above-mentioned drawings.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of them.

Based on the implementation manners in this application, all other implementation manners obtained by those of ordinary skill in the art without creative work fall within the protection scope of this application.

Please refer to FIG. 1, the charging system 10 runs in the electronic device 1. The electronic device 1 includes, but is not limited to, at least one processor 11 and a battery 12. The above-mentioned components may be connected via a bus or directly.

It should be noted that FIG. 1 is only an example of the electronic device 1. In other embodiments, the electronic device 1 may also include more or fewer elements, or have different element configurations. The electronic device 1 may be an electric motorcycle, an electric bicycle, an electric car, a mobile phone, a tablet computer, a digital assistant, a personal computer, or any other suitable rechargeable equipment.

In one embodiment, the battery 12 is a rechargeable battery for providing electrical energy to the electronic device 1. For example, the battery 12 may be a lithium ion battery, a lithium polymer battery, a lithium iron phosphate battery, or the like. The battery 12 includes at least one battery cell, and the battery 12 can be recharged repeatedly in a rechargeable manner.

Although not shown, the electronic device 1 may also include other components such as a wireless fidelity (Wireless Fidelity, WiFi) unit, a Bluetooth unit, a speaker, etc., which will not be repeated here.

Please refer to FIG. 2, which is a flowchart of a battery charging method according to an embodiment of the present application. The battery charging method may include the following steps:

Step S21: In the first stage, the battery is charged to the first stage voltage in the first charging mode or the second charging mode.

In this embodiment, the first charging mode includes N charging sub-phases in sequence, where N is an integer greater than or equal to 2, and the N charging sub-phases are respectively defined as the i-th charging sub-phase, i=2 , 3, ..., N. In the i-th charging sub-phase, the battery is charged with one of the i-th current, the i-th voltage, and the i-th power. In the i+1th charging sub-phase, the battery is charged with one of the i+1th current, the i+1th voltage, and the i+1th power. The charging current of the battery in the (i+1)th charging sub-phase is less than or equal to the charging current in the i-th charging sub-phase.

In this embodiment, the (i+1)th voltage is greater than or equal to the ith voltage, and the (i+1)th power is less than or equal to the ith power.

The second charging method includes M charging sub-phases in sequence, M is an integer greater than or equal to 2, the M charging sub-phases are defined as the j-th charging sub-phase, j = 1, 2, ..., M , And each of the j-th charging sub-stage includes a j-th pre-charge sub-stage and a j-th post-charge sub-stage; in one of the j-th pre-charge sub-stage and the j-th post-charge sub-stage, The battery is not charged or is charged or discharged with the j-th pre-charge sub-current for Tj1; in the other of the j-th pre-charge sub-stage and the j-th post-charge sub-stage, the battery is After the jth charger sub-current is charged for Tj2 time. Wherein, the absolute value of the j-th front charger current is smaller than the absolute value of the j-th rear charger current.

In this embodiment, the average value of the charging current of the j+1th charging substage is less than or equal to the charging current of the jth substage, and when the third charging method adopts the second charging method, the The average value of the charging current in the j charging sub-phase is smaller than the charging current in the first charging mode or the second charging mode.

It should be noted that the first stage voltage is equal to the charging limit voltage of the battery 12 (which can be understood as the charging limit voltage described in the background art).

Step S22: In the second stage, the battery is charged to the second stage voltage in a third charging mode, the second stage voltage is greater than the first stage voltage, and the third charging method adopts the first charging method Or the second charging method.

It should be noted that, when the first charging mode is adopted in the third charging mode, the number of charging sub-phases in the third charging mode N is equal to the number of charging sub-phases in the first charging mode. The number N may be the same or different. That is to say, when the third charging method adopts the first charging method, the number N of charging sub-phases in the second phase and the number N of charging sub-phases in the first phase may be The same or different.

When the third charging mode adopts the second charging mode, the number M of charging sub-phases in the third charging mode may be the same as the number M of charging sub-phases in the second charging mode. It can also be different. That is to say, when the third charging method adopts the second charging method, the number M of charging sub-phases in the second phase and the number M of charging sub-phases in the first phase may be The same or different.

In this embodiment, the charging current in the third charging mode is less than or equal to the charging current in the first charging mode or the second charging mode.

In one embodiment, when the battery 12 is charged in the first charging mode in the first stage, the first stage includes N charging sub-stages in sequence, where N is a positive integer, and the N charging The electronic phase is defined as the i-th charging sub-phase, i=2,...,N. In the i-th charging sub-phase, the battery 12 is charged with one of a constant i-th current, a constant i-th voltage, and a constant i-th power. When the battery 12 is charged in the first charging mode in the second stage, the second stage includes N charging sub-stages in sequence, where N is a positive integer, and the N charging sub-stages are defined respectively Is the i-th charging sub-stage, i=2,...,N. In the i-th charging sub-phase, the battery 12 is charged with one of a constant i-th current, a constant i-th voltage, and a constant i-th power. It can be understood that the number N of charging sub-stages in the first stage and the number N of charging sub-stages in the second stage may be the same or different.

In one embodiment, when the battery 12 is charged in the second charging mode in the first stage, the first stage includes M charging sub-stages in sequence, and M is an integer greater than or equal to 2, so The M charging sub-stages are respectively defined as the j-th charging sub-stage, j=1, 2, ..., M, and each of the j-th charging sub-stages includes the j-th pre-charging sub-stage and the j-th post-charging sub-stage; In one of the j-th pre-charge sub-phase and the j-th post-charge sub-phase, the battery is not charged or is charged or discharged with the j-th pre-charger current for Tj1; The other one of the pre-charge sub-phase and the j-th post-charge sub-phase charges the battery with the j-th post-charger current for a duration of Tj2. When the battery 12 is charged in the second charging mode in the second stage, the second stage includes M charging sub-stages in sequence, where M is an integer greater than or equal to 2, and the M charging The electronic phases are respectively defined as the j-th charging sub-phase, j = 1, 2, ..., M, and each of the j-th charging sub-phases includes the j-th pre-charge sub-phase and the j-th post-charge sub-phase; One of the j-th pre-charge sub-phase and the j-th post-charge sub-phase, the battery is not charged or is charged or discharged with the j-th pre-charge sub-current for Tj1; in the j-th pre-charge sub-phase And the other one of the j-th post-charge sub-phase, charging the battery with the j-th post-charge sub-current for Tj2. It is understandable that the number M of charging sub-stages in the first stage and the number M of charging sub-stages in the second stage may be the same or different.

In one embodiment, when the battery 12 is charged in the first charging mode in the first stage, the first stage includes N charging sub-stages in sequence, where N is a positive integer, and the N charging The electronic phase is defined as the i-th charging sub-phase, i=2,...,N. In the i-th charging sub-phase, the battery 12 is charged with one of a constant i-th current, a constant i-th voltage, and a constant i-th power. When the battery 12 is charged in the second charging mode in the second stage, the second stage includes M charging sub-stages in sequence, where M is an integer greater than or equal to 2, and the M charging The electronic phases are respectively defined as the j-th charging sub-phase, j = 1, 2, ..., M, and each of the j-th charging sub-phases includes the j-th pre-charge sub-phase and the j-th post-charge sub-phase; One of the j-th pre-charge sub-phase and the j-th post-charge sub-phase, the battery is not charged or is charged or discharged with the j-th pre-charge sub-current for Tj1; in the j-th pre-charge sub-phase And the other one of the j-th post-charge sub-phase, charging the battery with the j-th post-charge sub-current for Tj2.

In one embodiment, when the battery 12 is charged in the second charging mode in the first stage, the first stage includes M charging sub-stages in sequence, and M is an integer greater than or equal to 2, so The M charging sub-stages are respectively defined as the j-th charging sub-stage, j=1, 2, ..., M, and each of the j-th charging sub-stages includes the j-th pre-charging sub-stage and the j-th post-charging sub-stage; In one of the j-th pre-charge sub-phase and the j-th post-charge sub-phase, the battery is not charged or is charged or discharged with the j-th pre-charger current for Tj1; The other one of the pre-charge sub-phase and the j-th post-charge sub-phase charges the battery with the j-th post-charger current for a duration of Tj2. When the battery 12 is charged in the first charging mode in the second stage, the second stage includes N charging sub-stages in sequence, where N is a positive integer, and the N charging sub-stages are defined respectively Is the i-th charging sub-stage, i=2,...,N. In the i-th charging sub-phase, the battery 12 is charged with one of a constant i-th current, a constant i-th voltage, and a constant i-th power.

Since the charging current in the first charging sub-phase of the second phase is smaller than the current in the first phase, and the charging current in the i+1th charging sub-phase is less than or equal to the charging current in the i-th charging sub-phase , So that the anode potential of the battery 12 is not lower than a lithium evolution potential. Lithium evolution potential can be obtained by testing in the following ways. For the battery 12 in this embodiment, another three-electrode battery with the same specifications is fabricated. Compared with the battery 12 in this embodiment, the three-electrode battery has one more electrode, that is, it contains three electrodes, respectively. It is the anode, cathode and reference electrode. The material of the reference electrode is lithium, and the three-electrode battery is used for testing to obtain the lithium evolution potential of the anode of the battery 12 of this embodiment.

The specific test method for the lithium evolution potential of the anode is as follows: make a plurality of three-electrode batteries, and charge and discharge the three-electrode battery with charging currents of different magnifications (for example, 1C, 2C, 3C), and cycle multiple times ( For example, 10 times), and detect the potential difference between the anode and the reference electrode during the charge and discharge process. Then, the three-electrode battery was fully charged and disassembled, and the anodes of the three-electrode batteries charged with different rates were observed whether lithium evolution occurred (that is, whether lithium metal was deposited on the surface of the anode). To determine the maximum rate corresponding to the three-electrode battery without lithium evolution, the minimum potential difference between the anode and the reference electrode during the charge and discharge process at the rate is used as the anode lithium evolution potential. In addition, it should be noted that the charging current of lithium batteries is generally referred to by C, which is the value corresponding to the capacity of the lithium battery. Lithium battery capacity is generally expressed in Ah and mAh. For example, when the battery capacity is 1200mAh, the corresponding 1C is 1200mA, and 0.2C is equal to 240mA.

For another example, charge and discharge multiple three-electrode batteries with charging currents of 1C, 2C, and 3C, respectively, and cycle 10 times. Through dismantling the three-electrode battery, it is found that the anode does not undergo lithium evolution when using 1C and 2C charging and discharging, and the anode occurs when using 3C charging and discharging. Then, the minimum value of the potential difference between the anode and the reference electrode at the 2C rate is the anode lithium evolution potential. In addition, the lithium evolution potential of the cathode can also be tested in a similar manner, which will not be repeated here. The anode potential and cathode potential of the battery 12 can be further understood through the above-mentioned test process of the anode lithium evolution potential as follows: the anode potential is the potential difference between the anode and the reference electrode, that is, the anode versus lithium potential, and the cathode potential is the cathode and The potential difference of the reference electrode, that is, the potential of the cathode to lithium.

The second stage voltage is less than the oxidative decomposition voltage of the electrolyte in the battery 12. The oxidative decomposition voltage of the electrolyte in the battery can be understood as follows: when the potential of the battery exceeds a certain potential threshold, the solvent molecules, additive molecules, and even impurity molecules in the electrolyte will irreversibly reduce at the interface between the electrode and the electrolyte. Or oxidative decomposition reaction, this phenomenon is called electrolyte decomposition. The potential threshold is the reduction decomposition voltage and the oxidation decomposition voltage of the electrolyte in the battery.

The oxidative decomposition voltage of the electrolyte can be obtained by testing in the following way. For example, a symmetric battery (such as a button battery using Pt electrodes) is made, and the corresponding electrolyte is injected into the symmetric battery, that is, the same electrolyte as the electrolyte of the battery 12 in this embodiment. Referring again to FIG. 3, FIG. 3 illustrates that a gradually increasing voltage is applied to the symmetrical battery, and the voltage-to-current scanning is performed with the instrument to obtain the corresponding relationship between the voltage and the current. The horizontal axis is the voltage and the vertical axis is the current. In more detail, after the voltage is applied, the current value of the second voltage point sampled by the instrument is used as an initial current value (corresponding to the position P1 in Figure 3). Then, as the voltage gradually increases, when the instrument is installed When the sampled current value is equal to 100 times the initial current value, the corresponding voltage at this time is the oxidative decomposition voltage of the electrolyte. In the example of FIG. 3, it is the voltage corresponding to the position P2 of 6.2 volts. . In this embodiment, the second stage voltage is also less than or equal to the first stage voltage plus 500 millivolts.

During the Nth charging substage or the Mth charging substage of the second stage, the battery 12 is charged to the second stage voltage. At this time, the cut-off condition for charging the battery 12 Is a cut-off voltage, a cut-off current, or a cut-off capacity. More specifically, in the Nth charging substage or the Mth charging substage, when the charging current of the battery 12 is equal to the cut-off current, the generated charging voltage is equal to the cut-off voltage, or the battery 12 is detected When the state of charge (SOC) is equal to the cut-off capacity, the battery 12 is stopped from charging, that is, the charging is cut off. For the batteries 12 of different specifications, the cut-off current, the cut-off voltage, and the cut-off capacity can be obtained by using the aforementioned three-electrode battery test method and observing that the cathode of the three-electrode battery does not undergo excessive delithiation. In order to ensure that the electric capacity of the battery 12 is equivalent to the electric capacity of the conventional charging method in the prior art, and to ensure that the cathode of the battery 12 does not undergo excessive delithiation.

In addition, it should be supplemented that in this embodiment, the first-stage current, the first-stage voltage, the i-th current of the i-th sub-stage of the second stage, and the The value of the i voltage, one of the i-th power, the second stage voltage, and the cut-off condition may be pre-stored in the battery 12 or the processor 11, and the processor 11 Read the pre-stored value to correctly control the charging system 10 for charging.

Refer to Figure 4, where the horizontal axis is time and the vertical axis is current. In the first stage, at times t1, t2,..., t(i-2), t(i-1), ti,...tN, the voltages of the battery 12 are U1, U2,..., U( i-1), Ui,..., Ucl. In the second stage, at time t1', t2', t3', t4', t5',..., t(i-1)', ti', t(i+1)',...tN', all The voltages of the battery 12 are Ucl, U1', U2',..., Ui', U(i+1)',..., Um, respectively. It should be noted that the tN and t1' are the same time.

In the first stage, from time 0 to t1, the battery 12 is charged to the voltage U1 with a constant current I1; from time t1 to t2, the battery 12 is charged to the voltage U2 with a constant current I2; at time t(i-2) To t(i-1), charge with constant current I(i-1) to voltage U(i-1); from time ti-1 to ti, charge with constant current Ii to voltage Ui; at time t( Between N-1) and tN, charge to the voltage Ucl with a constant current Icl. Between time t2 and t(i-2), and between time ti and t(N-1), similar charging is performed, but it is omitted and not shown in the figure.

In the second stage, from time t1' to t2', the battery is charged with a constant current I1' to the voltage U1'; from time t2' to t3', the battery is charged with a constant voltage U1', the corresponding charging current for this period of time Decrease from I1' to current I2'; from time t3' to t4', charge the battery with a constant current I2' to voltage U2'; from time t4' to t5', charge the battery with a constant voltage U2'; Between time t(i-1)' and ti', charge the battery with a constant current Ii' to the voltage Ui'; between time ti' and t(i+1)', charge the battery with a constant voltage Ui', this period The charging current corresponding to time drops from I1' to the current I(i+1)'; between time t(N-2)' and t(N-1)', the charging current is charged to the voltage Um with a constant current Im; at time t From (N-1)' to tN', the battery is charged with a constant voltage Um, and the corresponding charging current during this period of time drops from Im to current Im'. From time t5' to t(i-1)', and from time t(i+1)' to t(N-1)', similar charging is performed, but it is omitted in the figure and not shown.

It should be noted that, in each of the N charging sub-stages of the first stage, the battery 12 is charged with a constant charging current, and I1≧I2≧…≧Icl, U1≦U2≦ …≦Ucl; In each of the N charging sub-phases of the second stage, the battery 12 is charged alternately with a constant charging current and a constant voltage, Icl≧I1'≧I2'≧…≧ Im', Ucl≦U1'≦U2'≦…≦Um.

Refer to Figure 5, where the horizontal axis is time and the vertical axis is current. In the first stage, at times t1, t2,...,ti,...tN, the voltages of the battery 12 are U1, U2,..., Ui,..., Ucl, respectively. In the second stage, at times t1', t2',...,ti', t(i+1)',...tN', the voltages of the battery 12 are U1', U2',..., Ui', U(i+1)',..., Um. It should be noted that the tN and t1' are the same time.

In the first stage, between time 0 and t1, the battery 12 is charged with a constant voltage U1 until the current is I1; between time t1 and t2, the battery 12 is charged with a constant voltage U2 until the current is I2; at time t(i- 1) Between ti, charge with a constant voltage Ui until the current is Ii; between time t(N-1) and tN, charge with a constant voltage Ucl until the current is Icl. Similar charging is performed between time t2 and t(i-1) and between time ti and t(N-1), but is omitted in the figure and not shown.

In the second stage, from time t1' to t2', the battery is charged with a constant current I1' to the voltage U1'; from time t2' to t3', the battery is charged with a constant voltage U1', the corresponding charging current for this period of time Decrease from I1' to current I2'; from time t3' to t4', charge the battery with a constant current I2' to voltage U2'; from time t4' to t5', charge the battery with a constant voltage U2'; Between time t(i-1)' and ti', charge the battery with a constant current Ii' to the voltage Ui'; between time ti' and t(i+1)', charge the battery with a constant voltage Ui', this period The charging current corresponding to time drops from Ii' to the current I(i+1)'; between time t(N-2)' and t(N-1)', the charging current is charged to the voltage Um with a constant current Im; at time t From (N-1)' to tN', the battery is charged with a constant voltage Um, and the corresponding charging current during this period of time drops from Im to current Im'. From time t5' to t(i-1)', and from time t(i+1)' to t(N-2)', similar charging is performed, but it is omitted in the figure and not shown.

It should be noted that, in each of the N charging sub-stages of the first stage, the battery 12 is charged with a constant charging voltage, and U1≦U2≦...≦Ucl, I1≧I2≧ …≧Icl. In each of the N charging sub-stages of the second stage, the battery 12 is charged alternately with a constant charging current and a constant charging voltage, and Ucl≦U1'≦U2'≦...≦Um , Icl≧I1'≧I2'≧…≧Im'.

Refer to Figure 6, where the horizontal axis is time, the left vertical axis is the power level, and the right vertical axis is the current level. In the first stage, at times t1, t2,..., t(i-1), ti,...tN, the voltages of the battery 12 are U1, U2,..., U(i-1), Ui,... , Ucl. In the second stage, at times t2', t4',...,ti',...,t(N-1)', the voltages of the battery 12 are U1', U2',..., Ui',..., Um. It should be noted that the tN and t1' are the same time.

In the first stage, from time 0 to t1, the battery 12 is charged with a constant power P1 to the voltage U1; from time t1 to t2, the battery 12 is charged with a constant power P2 to the voltage U2; at time t(i-2 Between) and t(i-1), charge with constant power P(i-1) to voltage U(i-1); between time t(i-1) and ti, charge with constant power Pi to voltage Ui; Between time t(N-1) and tN, the constant power Pcl is charged to the voltage Ucl. Between time t2 and t(i-2), and between time ti and t(N-1), similar charging is performed, but it is omitted and not shown in the figure.

In the second stage, from time t1' to t2', the battery is charged with a constant current I1' to the voltage U1'; from time t2' to t3', the battery is charged with a constant voltage U1', the corresponding charging current for this period of time Decrease from I1' to current I2'; from time t3' to t4', charge the battery with a constant current I2' to voltage U2'; from time t4' to t5', charge the battery with a constant voltage U2'; Between time t(i-1)' and ti', charge the battery with a constant current Ii' to the voltage Ui'; between time ti' and t(i+1)', charge the battery with a constant voltage Ui', this period The charging current corresponding to time drops from I1' to the current I(i+1)'; between time t(N-2)' and t(N-1)', the charging current is charged to the voltage Um with a constant current Im; at time t From (N-1)' to tN', the battery is charged with a constant voltage Um, and the corresponding charging current during this period of time drops from Im to current Im'. From time t5' to t(i-1)', and from time t(i+1)' to t(N-2)', similar charging is performed, but it is omitted in the figure and not shown.

It should be noted that, in each of the N charging sub-stages of the first stage, the battery 12 is charged with a constant power, and P1≧P2≧…≧Pcl, U1≦U2≦… ≦Ucl. In each of the N charging sub-stages of the second stage, the battery 12 is charged alternately with a constant charging current and a constant charging voltage, and Ucl≦U1'≦U2'≦...≦Um , Icl≧I1'≧I2'≧…≧Im'.

Refer to Figure 7, where the horizontal axis is time and the vertical axis is current. In the first stage, at times t1, t2,..., t(i-2), t(i-1), ti,...tN, the voltages of the battery 12 are U1, U2,..., U(i -1), Ui,..., Ucl. In the second stage, at times t2', t4',..., t(i-1)', ti',..., t(N-1)', the voltage of the battery 12 is U1', U2', respectively ,..., Ui',..., Um. It should be noted that the tN and t1' are the same time.

In the first stage, from time 0 to t1, the battery 12 is charged with a constant current I1 to the voltage U1; from time t1 to t2, the battery is charged with a constant voltage U1, and the corresponding charging current during this period is changed from I1 Decrease to current I2; between time t2 and t3, charge the battery with constant current I2 to voltage U2; between time t3 and t4, charge the battery with constant voltage U2, the corresponding charging current for this period of time decreases from I2 to current I3; From time t(i-2) to t(i-1), charge the battery with a constant current Ii to the voltage Ui; from time t(i-1) to ti, charge the battery with a constant voltage Ui; at time t( From N-2) to t(N-1), charge the battery with a constant current Icl to the voltage Ucl; from time t(N-1) to tN, charge the battery with a constant voltage Ucl, the corresponding charging current for this period of time is from Icl drops to the current I1'. Between time t4 and t(i-2), and between time ti and t(N-2), similar charging is performed, but it is omitted and not shown in the figure.

In the second stage, from time t1' to t2', the battery is charged with a constant current I1' to the voltage U1'; from time t2' to t3', the battery is charged with a constant voltage U1', the corresponding charging current for this period of time Decrease from I1' to current I2'; from time t3' to t4', charge the battery with a constant current I2' to voltage U2'; from time t4' to t5', charge the battery with a constant voltage U2'; Between time t(i-1)' and ti', charge the battery with a constant current Ii' to the voltage Ui'; between time ti' and t(i+1)', charge the battery with a constant voltage Ui', this period The charging current corresponding to time drops from I1' to the current I(i+1)'; between time t(N-2)' and t(N-1)', the charging current is charged to the voltage Um with a constant current Im; at time t From (N-1)' to tN', the battery is charged with a constant voltage Um, and the corresponding charging current during this period of time drops from Im to current Im'. Between time t5' and t(i-1)' and between time t(i+1)' and t(N-2)', similar charging is performed, but it is omitted in the figure and not shown.

It should be noted that, in each of the N charging sub-stages of the first stage, a constant charging current and a constant charging voltage alternately charge the battery 12, and I1≧I2≧…≧Icl, U1 ≦U2≦…≦Ucl. In each of the N charging sub-stages of the second stage, the battery 12 is also alternately charged with a constant charging current and a constant charging voltage, and I1'≧I2'≧…≧Im' , U1'≦U2'≦...≦Um, and Icl≧I1', Ucl≦U1'.

When the second charging method is used to charge the battery 12, the first stage includes M charging sub-stages in sequence, where M is an integer greater than or equal to 2, and the M charging sub-stages are respectively defined as the jth charger Stages, j=1, 2,..., M, each of the j-th charging sub-stages includes the j-th pre-charging sub-stage and the j-th post-charging sub-stage. The second stage also includes sequential M charging substages, M is an integer greater than or equal to 2, and the M charging substages are respectively defined as the jth charging substage, j=1, 2,..., M, each of the j-th charging sub-stages includes a j-th pre-charging sub-stage and a j-th post-charging sub-stage. It should be noted that the number M of charging sub-stages in the first stage and M in the second stage may be the same or different.

In one of the j-th pre-charge sub-phase and the j-th post-charge sub-phase, the processor 11 controls the charging system 10 not to charge the battery 12 or uses a j-th pre-charge sub-current Charge or discharge for Tj1 time. In the other of the j-th pre-charge sub-phase and the j-th post-charge sub-phase, the processor 11 controls the charging system 10 to charge the battery 12 with a j-th post-charge sub-current Up to Tj2 time. The absolute value of the j-th front charger current is smaller than the absolute value of the j-th rear charger current.

That is to say, in each of the jth charging substages, the battery 12 is charged in a pulse charging or pulse charging and discharging manner, and the average charging current of the j+1 charging substages is The value is less than or equal to the charging current of the jth charging sub-stage, for example, (the first front charger current×T11+the first rear charger current×T12)/(T11+T12) is greater than or equal to (the second front charger current×T12) Current×T21+second rear charger current×T22)/(T21+T22), (second front charger current×T21+second rear charger current×T22)/(T21+T22) is greater than or equal to (third front Charger current×T31+third post-charger current×T32)/(T31+T32) and so on. The sum of the duration of each Tj1 and the duration of Tj2 is the charging period or the charging and discharging period of the pulse charging or the pulse charging and discharging in the jth charging sub-phase.

In addition, it should be noted that in this embodiment, in the j-th pre-charge sub-stage, the j-th pre-charge sub-current is used to charge or discharge for Tj1 time, and in the j-th post-charge sub-stage The charging is performed with the j-th post-charger current for a duration of Tj2. In other embodiments, the j-th post-charger current may be used for charging for Tj2 in the j-th pre-charge sub-stage, and the j-th pre-charge sub-stage may be charged with the j-th pre-charge sub-stage. The charger current is charged or discharged for a duration of Tj1. In other embodiments, it is also possible to not charge or stand still (that is, the charging current at this time is 0) for Tj1 in the j-th pre-charge sub-phase, and in the j-th post-charge sub-phase, use the After the jth sub-current is charged or discharged for Tj2 time.

Refer to Figure 8, where the horizontal axis is time and the vertical axis is current. In the first stage, between time 0 and t1, the processor 11 controls the charging system 10 to charge the battery 12 to the voltage U1 with a current I1. During time t1 to t1000, that is, in each charging sub-phase from the first charging sub-phase to the 1000th charging sub-phase of the first phase, the processor 11 controls the charging system 10 The battery 12 is charged with the current I2 first, and then the battery 12 is charged with the current I3. Between time tx and t1000, similar charging is performed, but it is omitted and not shown in the figure.

Between time t1000 and t2000, that is, in each sub-charging stage from the 1001th charging sub-stage to the 2000th charging sub-stage of the first stage, the processor 11 controls the charging system 10 The battery 12 is first charged with the current I10011, and then the battery 12 is allowed to stand still (that is, neither charging nor discharging). Between time ty and t2000, similar charging is performed, but it is omitted and not shown in the figure. Between time t2000 and tM, that is, in each charging sub-stage from the 2001th charging sub-stage to the M-th charging sub-stage of the first stage, the processor 11 controls the charging system 10 The battery 12 is charged with the current I20011 first, and then the battery 12 is discharged with the current I20012 until the voltage of the battery 12 is equal to the voltage Ucl (ie, cut-off voltage). Between time t2002 and t(M-1), similar charging is performed, but it is omitted and not shown in the figure.

That is, in the M charging sub-phases of the first phase, the battery 12 is charged in three different pulse charging or pulse charging and discharging methods. In addition, it should be noted that: the pulse charging or pulse charging and discharging charging cycle or charging and discharging cycle of each of the M charging sub-phases is the same, that is, t1=(t1001-t1000)=(t2001-t2000), and in the other In the embodiment, the charging period or the charging and discharging period of different pulse charging or pulse charging and discharging may also be different.

In the second stage, from time t1' to t2', the battery is charged with a constant current I1' to the voltage U1'; from time t2' to t3', the battery is charged with a constant voltage U1', the corresponding charging current for this period of time Decrease from I1' to current I2'; from time t3' to t4', charge the battery with a constant current I2' to voltage U2'; from time t4' to t5', charge the battery with a constant voltage U2'; Between time ti' and t(i+1)', charge with constant current Ii' to voltage Ui'; between time t(i+1)' and t(i+2)', use constant voltage Ui' to For battery charging, the charging current corresponding to this period of time drops from I1' to current I(i+1)'; between time t(M-2)' to t(M-1)', charge to voltage with constant current Im Um; between time t(M-1)' and tM', the battery is charged with a constant voltage Um, and the corresponding charging current during this period of time drops from Im to current Im'. From time t5' to ti', and from time t(i+2)' to t(M-2)', similar charging is performed, but it is omitted in the figure and not shown.

Step S23: In the third stage, charge the battery at a constant voltage with the second stage voltage.

In this embodiment, in the third stage, the battery is charged at a constant voltage with the second stage voltage until the battery reaches a fully charged state, thereby completing the entire charging process.

In summary, the charging method uses at least one of constant current, constant voltage, or constant power to charge the battery to the first stage voltage in the first stage, that is, it can charge the battery to the first stage voltage in the first stage. Is one or more of them and performs one or more times of charging; and in the second stage, at least one of constant current, constant voltage or constant power is charged to charge the battery to the second stage voltage, also That is, in the second stage, one or more of them can be charged one or more times. Alternatively, the charging method of pulse charging or pulse charging and discharging may also be used in the first stage and the second stage. Through the charging method of the present application, the early stage (first stage) of battery charging can be optimized to greatly reduce the conventional charging time in the early stage, reduce the risk of lithium evolution, shorten the cathode high potential time, thereby improving the cycle life of the battery cell and increasing the charging speed. And the charging voltage of the battery is increased from the first stage voltage (that is, the charging limit voltage described in the background art) to the second stage voltage, so that the charging speed of the battery during the charging process can be increased, and the total Charging time.

In order to make the invention objectives, technical solutions, and technical effects of the present application clearer, the following further describes the present application in detail with reference to the accompanying drawings and embodiments. The battery system used in each comparative example and each embodiment of this application uses LiCoO ₂ as the cathode, graphite as the anode, plus a diaphragm, electrolyte and packaging shell, through mixing, coating, assembling, forming and aging processes production. Part of the battery cell is wound with a reference electrode between the cathode and anode pole pieces to make a three-electrode battery to test the difference between the cathode potential and the anode potential of the battery during the charging process.

The charging limit voltage Ucl of the battery of each comparative example and each embodiment of this application is 4.4V. It is explained here that the charging method of this application can be applied to batteries of various voltage systems, and is not limited to the 4.4V system. By comparing the charging method in the prior art (constant current and constant voltage charging) used in the comparative example with the charging method of the present application used in the examples, the charging speed and the capacity retention rate after 500 cycles are compared.

The comparative example 1 stated below uses the charging method in the prior art to charge the battery, and the comparative example 2 uses the charging method in the prior art to increase the voltage of the constant voltage charging process to charge the battery.

Comparative example 1

Ambient temperature: 45°C.

Charging and discharging process:

Step 1: Use a constant current of 0.7C to charge the battery until the battery voltage reaches the cut-off voltage of 4.4V (which can be understood as the charging limit voltage);

Step 2: Continue to charge the battery with a constant voltage of 4.4V until the battery current reaches the cut-off current 0.05C;

Step 3: Let the battery stand for 5 minutes;

Step 4: Use a constant current of 0.5C to discharge the battery until the battery voltage is 3.0V;

Step 5: Let the battery stand for 5 minutes;

Step 6: Repeat the above steps 1 to 5 for 500 cycles.

Comparative example 2

The ambient temperature is 45°C.

Charging and discharging process:

Step 1: Use a constant current of 0.7C to charge the battery until the battery voltage reaches 4.4V;

Step 2: Continue to charge the battery with a constant current of 0.5C until the battery voltage reaches the cut-off voltage of 4.45V (which can be understood as the charging limit voltage);

Step 3: Use a constant voltage of 4.45V to charge the battery until the battery current reaches the cut-off current 0.13C;

Step 4: Let the battery stand for 5 minutes;

Step 5: Use a constant current of 0.5C to discharge the battery until the battery voltage is 3.0U

Step 6: Let the battery stand for 5 minutes;

Step 7: Repeat the above steps 1 to 6 for 500 cycles.

Example 1

The ambient temperature is 45°C.

Charging and discharging process:

Step 1: Use a constant current of 1C to charge the battery until the battery voltage reaches 4.2V;

Step 2: Use a constant current of 0.8C to charge the battery until the battery voltage reaches the cut-off voltage of 4.3V;

Step 3: Use a constant current of 0.6C to charge the battery until the battery voltage reaches 4.4V;

Step 4: Use a constant voltage of 4.4V to charge the battery until the battery current reaches 0.4C;

Step 5: Use a constant current of 0.4C to charge the battery until the battery voltage reaches the cut-off voltage of 4.45V;

Step 6: Continue to charge the battery with a constant voltage of 4.45V until the battery current reaches the cut-off current 0.13C;

Step 7: Let the battery stand for 5 minutes;

Step 8: Use a constant current of 0.5C to discharge the battery until the battery voltage is 3.0U;

Step 9: Let the battery stand for 5 minutes;

Step 10: Repeat the above steps 1 to 9 for 500 cycles.

Example 2

The ambient temperature is 45°C.

Charging and discharging process:

Step 1: Use a constant voltage of 4V to charge the battery until the battery current reaches 0.9C;

Step 2: Use a constant voltage of 4.2V to charge the battery until the battery current reaches 0.7C;

Step 3: Use a constant voltage of 4.35V to charge the battery until the battery current reaches 0.5C;

Step 4: Use a constant current of 0.5C to charge the battery until the battery voltage reaches 4.4V;

Step 5: Use a constant voltage of 4.4V to charge the battery until the battery current reaches 0.3C;

Step 6: Use a constant current of 0.3C to charge the battery until the battery voltage reaches the cut-off voltage of 4.45V;

Step 7: Continue to charge the battery with a constant voltage of 4.45V until the battery current reaches the cut-off current 0.13C;

Step 8: Let the battery stand for 5 minutes;

Step 9: Use a constant current of 0.5C to discharge the battery until the battery voltage is 3.0U;

Step 10: Let the battery stand for 5 minutes;

Step 11: Repeat the above steps 1 to 10 for 500 cycles.

Example 3

The ambient temperature is 45°C.

Charging and discharging process:

Step 1: Use a constant current of 0.7C to charge the battery until the battery voltage reaches 4.3V;

Step 2: Use a constant voltage of 4.3V to charge the battery until the battery current reaches the cut-off current 0.5C;

Step 3: Use a constant current of 0.5C to charge the battery until the battery voltage reaches 4.4V;

Step 4: Use a constant voltage of 4.4V to charge the battery until the battery current reaches the cut-off current 0.3C;

Step 5: Use a constant current of 0.3C to charge the battery until the battery voltage reaches the cut-off voltage of 4.45V;

Step 7: Let the battery stand for 5 minutes;

Step 9: Let the battery stand for 5 minutes;

Step 10: Repeat the above steps 1 to 9 for 500 cycles.

Example 4

The ambient temperature is 45°C.

Charging and discharging process:

Step 1: Use a constant power of 8W to charge the battery until the battery voltage reaches 4.3V;

Step 2: Use a constant power of 6.5W to charge the battery until the battery voltage reaches 4.4V;

Step 3: Use a constant voltage of 4.4V to charge the battery until the battery current reaches 0.5C;

Step 5: Use a constant current of 0.5C to charge the battery until the battery voltage reaches the cut-off voltage of 4.45V;

Step 7: Let the battery stand for 5 minutes;

Step 9: Let the battery stand for 5 minutes;

Step 10: Repeat the above steps 1 to 8 for 500 cycles.

Example 5

The ambient temperature is 45°C.

Charging and discharging process:

Step 1: Leave the battery for 0.9s;

Step 2: Use a constant current of 0.7C to charge the battery for 9.1s. When the battery voltage is greater than or equal to 4.4V, skip to step 4;

Step 3: Repeat the above steps 1 to 3 for 100,000 cycles;

Step 4: Use a constant current of 0.05C to discharge the battery for 1s;

Step 5: Use a constant voltage of 4.4V to charge the battery until the battery current reaches 0.5C;

Step 6: Use a constant current of 0.5C to charge the battery until the battery voltage reaches the cut-off voltage of 4.45V;

Step 8: Let the battery stand for 5 minutes;

Step 9: Repeat the above steps 1 to 8 for 500 cycles.

The batteries of Examples 1-5 and Comparative Examples 1-2 were tested for capacity retention and full charge time, and the test results are recorded in Table 1 below. The capacity retention rate is tested by the following method: when the ambient temperature is 45°C, the batteries of the comparative example and the examples are cycled for 500 cycles using the corresponding charging process, and then the discharge capacity of the battery after 500 cycles is divided by the first cycle of the cycle The discharge capacity at the time to obtain the capacity retention rate.

Table 1 Test results of Examples 1-5 and Comparative Examples 1-2

It can be seen from Table 1 that by comparing Examples 1 to 5 with Comparative Example 1, it can be known that the charging method provided by the embodiment of the present application is compared with the constant current and constant voltage charging method in the prior art (ie, against Proportion 1) enables the battery to maintain a higher capacity retention rate during the cycle of use, and can greatly shorten the time required for the battery to reach full charge. Comparing Example 1 to Example 5 with Comparative Example 2, it can be seen that the charging method provided by the embodiment of the present application is compared with the charging method in the prior art for increasing the voltage during the constant voltage charging process (ie Comparative Example 2). It can also make the battery maintain a higher capacity retention rate during the cycle of use, and can also greatly shorten the time required for the battery to reach full charge.

Therefore, the present application charges the battery to the first stage voltage by at least one of constant current, constant voltage or constant power in the first stage; and uses constant current, constant voltage or constant power in the second stage. At least one of the ways to charge the battery to the second stage voltage. Alternatively, the charging method of pulse charging or pulse charging and discharging may also be used in the first stage and the second stage. The charging method of the present application can optimize the initial stage (first stage) of battery charging to reduce the regular initial charging time, reduce the risk of lithium evolution, shorten the cathode high potential time, thereby improve the cycle life of the battery cell and increase the charging speed. In addition, the charging voltage of the battery is increased from the first stage voltage (that is, the charging limit voltage) to the second stage voltage, so that the charging speed of the battery during the charging process can be increased, and the total charging time can be shortened.

Referring to FIG. 9, in this embodiment, the charging system 10 may be divided into one or more modules, and the one or more modules may be stored in the processor 11 and used by the processor 11 Perform the charging method of the embodiment of the present application. The one or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the charging system 10 in the electronic device 1. For example, the charging system 10 may be divided into the first charging module 101, the second charging module 102, and the third charging module 103 in FIG. 9.

The first charging module 101 is used to charge the battery to the first-phase voltage in the first charging mode or the second charging mode in the first stage; the second charging module 102 is used to charge the battery to the first-stage voltage in the second stage The three charging methods charge the battery to the second stage voltage, the second stage voltage is greater than the first stage voltage, wherein the third charging method adopts the first charging method or the second charging method; The third charging module 103 is used to charge the battery with a constant voltage at the second stage voltage in the third stage.

Through the charging system 10, the battery 12 can be charged and managed to improve the charging efficiency of the battery and improve the high-temperature cycle life of the cells in the battery. For specific content, please refer to the embodiment of the above battery charging method, which will not be described in detail here.

In an embodiment, the processor 11 may be a central processing unit (Central Processing Unit, CPU), or other general-purpose processors, digital signal processors (Digital Signal Processors, DSPs), and application specific integrated circuits (Application Specific Integrated Circuits). Integrated Circuit, ASIC), Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the processor 11 may also be any other conventional processor or the like.

If the modules in the charging system 10 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, this application implements all or part of the processes in the above-mentioned embodiments and methods, and can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the foregoing method embodiments. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file, or some intermediate forms. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory) , Random Access Memory (RAM, Random Access Memory), electrical carrier signal, telecommunications signal, and software distribution media, etc. It should be noted that the content contained in the computer-readable medium can be appropriately added or deleted according to the requirements of the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to the legislation and patent practice, the computer-readable medium Does not include electrical carrier signals and telecommunication signals.

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

In another embodiment, the electronic device 1 may further include a memory (not shown), and the one or more modules may also be stored in the memory and executed by the processor 11. The memory may be an internal memory of the electronic device 1, that is, a memory built in the electronic device 1. In other embodiments, the memory may also be an external memory of the electronic device 1, that is, a memory external to the electronic device 1.

In some embodiments, the memory is used to store program codes and various data, for example, to store the program codes of the charging system 10 installed in the electronic device 1, and realize high-speed, high-speed, Automatically complete the access of programs or data.

The memory may include random access memory, and may also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, Flash Card, at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device.

For those skilled in the art, it is obvious that the present application is not limited to the details of the foregoing exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the application. Therefore, no matter from which point of view, the above-mentioned embodiments of this application should be regarded as exemplary and non-restrictive. The scope of this application is defined by the appended claims rather than the above description, so it is intended that All changes falling within the meaning and scope of equivalent elements of the claims are included in this application.

Claims

A method for charging a battery, characterized in that it comprises:

In the first stage, the battery is charged to the first stage voltage by the first charging method or the second charging method, wherein the first charging method includes N charging sub-stages in sequence, and N is an integer greater than or equal to 2 , The N charging sub-stages are respectively defined as the i-th charging sub-stage, i=2, 3,..., N; in the i-th charging sub-stage, the i-th current, the i-th voltage and the i-th power are One of them charges the battery; in the i+1th charging sub-stage, the battery is charged with one of the i+1th current, the i+1th voltage, and the i+1th power; wherein , The charging current of the battery in the (i+1)th charging sub-phase is less than or equal to the charging current in the i-th charging sub-phase;

The second charging method includes M charging sub-phases in sequence, M is an integer greater than or equal to 2, the M charging sub-phases are defined as the j-th charging sub-phase, j = 1, 2, ..., M , And each of the j-th charging sub-stage includes a j-th pre-charge sub-stage and a j-th post-charge sub-stage; in one of the j-th pre-charge sub-stage and the j-th post-charge sub-stage, The battery is not charged or is charged or discharged with the j-th pre-charge sub-current for Tj1; in the other of the j-th pre-charge sub-stage and the j-th post-charge sub-stage, the battery is The j-th post-charger current is charged for a duration of Tj2; wherein the absolute value of the j-th pre-charger current is less than the absolute value of the j-th post-charger current; and

In the second stage, the battery is charged to the second stage voltage in a third charging mode, and the second stage voltage is greater than the first stage voltage, and the third charging method adopts the first charging method or the The second charging method.
The charging method according to claim 1, wherein when the third charging method adopts the first charging method, the number of charging sub-stages N between the two is the same.
The charging method according to claim 1, wherein when the third charging method adopts the second charging method, the number of charging sub-stages M between the two is the same.
8. The charging method of claim 1, wherein the i+1th voltage is greater than or equal to the ith voltage.
The charging method according to claim 1, wherein the (i+1)th power is less than or equal to the (i)th power.
The charging method of claim 1, wherein the average value of the charging current of the j+1 charging sub-phase is less than or equal to the charging current of the j-th sub-phase, and when the third charging method adopts all the charging currents. In the second charging mode, the average value of the charging current in the jth charging substage is smaller than the charging current in the first charging mode or the second charging mode.
3. The charging method of claim 1, wherein the first stage voltage is equal to the charge limit voltage of the battery, and the second stage voltage is less than the oxidative decomposition voltage of the electrolyte in the battery.
The charging method of claim 1, wherein the second stage voltage is less than or equal to the first stage voltage plus 500 millivolts.
The charging method according to claim 1, wherein the method further comprises:

In the third stage, the battery is charged at a constant voltage with the second stage voltage.
The charging method according to claim 1, wherein the charging current in the third charging mode is less than or equal to the charging current in the first charging mode or the second charging mode.
An electronic device, characterized in that the electronic device comprises:

Battery; and

The processor is configured to execute the charging method according to any one of claims 1 to 10 to charge the battery.
A storage medium having at least one computer instruction stored thereon, wherein the instruction is loaded by a processor and used to execute the charging method according to any one of claims 1 to 10.