CN114801872A

CN114801872A - Battery charging method and device, battery management system and battery

Info

Publication number: CN114801872A
Application number: CN202210273031.9A
Authority: CN
Inventors: 沈海杰
Original assignee: Dongguan Amperex Technology Ltd
Current assignee: Dongguan Amperex Technology Ltd
Priority date: 2022-03-18
Filing date: 2022-03-18
Publication date: 2022-07-29

Abstract

The application discloses a battery charging method and device, a battery management system and a battery, wherein the charging method comprises n stages of charging and discharging cycles, and n is an integer not less than 3. And in the charge-discharge cycle process of each stage within the (n-1) th stage, the charge cut-off current of the battery in the constant-voltage charge stage in the charge-discharge cycle of the corresponding stage is reduced in sequence. And during the charge and discharge cycle of the nth stage, adjusting the nth charge cut-off current of the battery in the constant voltage charge stage in the charge and discharge cycle of the nth stage to be a first current, wherein the first current is not less than the 1 st charge cut-off current of the battery in the 1 st stage. Through the mode, the endurance time and the cycle life of the battery can be prolonged.

Description

Battery charging method and device, battery management system and battery

Technical Field

The present disclosure relates to the field of battery technologies, and in particular, to a battery charging method and apparatus, a battery management system, and a battery.

Background

The endurance time and the service life of the battery are the core experience of a mobile phone user, so that the improvement of the cycle life of the battery has great significance for improving the user experience. And because the battery charging scheme has important influence on the endurance time and the cycle life of the battery, the endurance time and the cycle life of the battery can be effectively prolonged by selecting a proper charging scheme.

Disclosure of Invention

In the process of implementing the present application, the inventors of the present application found that: at present, a constant charge cut-off current is generally adopted to charge a battery, no adjustment is made in the use process of the battery, and the original charging strategy is kept. However, since the off-current of the charging is kept constant, the capacity of the lithium ion battery is continuously reduced in the using process, and the endurance and the service life of the battery are shortened.

The application aims to provide a battery charging method and device, a battery management system and a battery, which can prolong the endurance time and the cycle life of the battery.

In order to achieve the above object, in a first aspect, embodiments of the present application provide a method for charging a battery, which includes n stages of charge and discharge cycles, where n is an integer greater than or equal to 3. The charging method comprises the following steps: and determining the charge-discharge cycle of the battery in n stages, wherein n is an integer more than or equal to 3. And in the charge-discharge cycle process of each stage within the (n-1) th stage, the charge cut-off current of the battery in the constant-voltage charge stage in the charge-discharge cycle of the corresponding stage is reduced in sequence. And during the charge and discharge cycle of the nth stage, adjusting the nth charge cut-off current of the battery in the constant voltage charge stage in the charge and discharge cycle of the nth stage to be a first current, wherein the first current is not less than the 1 st charge cut-off current of the battery in the 1 st stage.

In an optional manner, the charging method further includes: and acquiring characteristic parameters of the battery in each charge and discharge cycle process. And determining the charge-discharge cycles of the battery in n stages according to the characteristic parameters.

In an alternative mode, the n-stage charge-discharge cycle of the battery is determined according to the characteristic parameters, and the method comprises the following steps: when it is at the (A) th place ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameter of the charge-discharge cycle process satisfies the followingUnder the condition that m is more than or equal to 1 and less than n-1, the (A) th layer ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) A charge-discharge cycle and the (A) th cycle ₁ +A ₂ +A ₃ …+A _m ) The charge-discharge cycle between the charge-discharge cycles is determined as the charge-discharge cycle of the m-th stage. If m is n-1, the second one (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) A charge-discharge cycle and the (A) th cycle ₁ +A ₂ +A ₃ …+A _m ) Determining the charge-discharge cycle between the charge-discharge cycles as the m-stage charge-discharge cycle, and determining the (A) -th stage ₀ +A ₁ +A ₂ +A ₃ … +A _m ) The charge and discharge cycles and thereafter are determined as the charge and discharge cycles of the m +1 th stage to determine the charge and discharge cycles of the n stages of the battery. Wherein A is ₁ 、A ₂ 、A ₃ …A _m Are all integers greater than 0, and A ₀ ＝1。

In an alternative mode, the characteristic parameter includes a charge temperature variation amount, a discharge temperature variation amount, a charge time, or a discharge time of the battery during a charge-discharge cycle. The first (A) ₀ +A ₁ +A ₂ +A ₃ … +A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameters of the charge-discharge cycle process meet a first condition, which comprises the following steps: the first (A) ₁ +A ₂ +A ₃ …+A _m ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) The difference of the characteristic parameters in the charging and discharging cycle process is not less than a first difference threshold.

In an alternative form, the characteristic parameter includes a charge capacity or a discharge capacity of the battery during charge and discharge cycles. The first (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during a charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameters of the charge-discharge cycle process meet a first condition, which comprises the following steps: the first (A) ₁ +A ₂ +A ₃ …+A _m ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₀ +A ₁ +A ₂ +A ₃ … +A _m-1 ) The ratio of the characteristic parameters of the charge-discharge cycle process is not more than a first ratio threshold.

In an alternative mode, the n-stage charge-discharge cycle of the battery is determined according to the characteristic parameters, and the method comprises the following steps: when it is in (B) ₁ +B ₂ +B ₃ …+B _k ) When the characteristic parameter of the charge-discharge cycle process meets a second condition, if k is more than or equal to 1 and less than n-1, determining that the (B) th cycle process is carried out ₀ +B ₁ +B ₂ +B ₃ …+B _k-1 ) A charge-discharge cycle and the (B) th cycle ₁ +B ₂ +B ₃ …+B _k ) The charge-discharge cycle between the charge-discharge cycles is determined as the charge-discharge cycle of the kth stage. If k is n-1, the second (B) is ₀ +B ₁ +B ₂ +B ₃ …+B _k-1 ) A charge-discharge cycle and the (B) th cycle ₁ +B ₂ +B ₃ … +B _k ) Determining a charge-discharge cycle between charge-discharge cycles as a charge-discharge cycle of the kth stage, and determining the (B) th stage ₀ +B ₁ +B ₂ +B ₃ …+B _k ) The charge and discharge cycles and the following charge and discharge cycles are determined as the charge and discharge cycles of the k +1 th stage so as to determine the charge and discharge cycles of the n stages of the battery. Wherein, B ₁ 、B ₂ 、 B ₃ …B _k Are all integers greater than 0, and B ₀ ＝1。

In an alternative form, the characteristic parameter includes a charge current, a discharge current or an ambient temperature sensed by the battery during a charge-discharge cycle. The first (A) ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameters of the charge-discharge cycle process meet a second condition, which comprises the following steps: the first (A) ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameter of each charge-discharge cycle process is within a first variation range threshold.

In an alternative mode, during the charge-discharge cycle of each stage within the (n-1) th stage, the method for sequentially reducing the charge cutoff current of the battery in the constant-voltage charge stage of the charge-discharge cycle of the corresponding stage includes: and in the charge-discharge cycle process of each stage within the (n-2) th stage, setting n-2 adjustment quantities, wherein each stage corresponds to one adjustment quantity. And calculating the difference between the t-th charging cut-off current in the t-th stage and the adjustment amount corresponding to the t-th stage, and taking the difference as the t + 1-th charging cut-off current in the t + 1-th stage to sequentially reduce the charging cut-off current when the battery is in the constant voltage charging stage in the charging and discharging cycle of the corresponding stage, wherein t is more than or equal to 1 and less than or equal to n-2.

In a second aspect, another embodiment of the present application provides a charging apparatus for a battery, including a first determining module, a first adjusting module, and a second adjusting module. The first determination module is used for determining charge-discharge cycles of n stages of the battery, wherein n is an integer larger than or equal to 3. The first adjusting module is used for sequentially reducing the charging cut-off current of the battery in the constant-voltage charging stage in the charging and discharging cycle process of each stage within the (n-1) th stage. The second adjusting module is used for adjusting the nth charging cut-off current of the battery in the constant voltage charging stage in the charging and discharging cycle of the nth stage to be a first current in the charging and discharging cycle of the nth stage, wherein the first current is not less than the 1 st charging cut-off current of the battery in the 1 st stage.

In a third aspect, the present application provides a charging device for a battery, comprising: at least one processor and a memory communicatively connected to the at least one processor, the memory storing instructions executable by the at least one processor, the instructions being executable by the at least one processor to enable the at least one processor to perform a method of charging a battery as in the first aspect.

In a fourth aspect, another embodiment of the present application provides a battery management system, which includes the charging device for the battery in the third aspect.

In a fifth aspect, another embodiment of the present application provides a battery, which includes a battery core and the battery management system in the fourth aspect.

In a sixth aspect, another embodiment of the present application provides an electric device, which includes a load and the battery in the fifth aspect. Wherein the battery is used to power the load.

In a seventh aspect, another embodiment of the present application provides a non-transitory computer-readable storage medium storing computer-executable instructions that, when executed by a charging apparatus for a battery, cause the charging apparatus for the battery to perform the method for charging the battery in the first aspect.

The application has the following beneficial effects: the method for charging a battery provided by the application comprises n stages of charge-discharge cycles. And then, in the charging and discharging circulation process of each stage within the (n-1) th stage, the charging cut-off current of the battery in the constant voltage charging stage in the charging and discharging circulation of the corresponding stage is sequentially reduced, so that the charging and discharging capacity is improved, and the battery duration is prolonged. Meanwhile, in the charging and discharging circulation process of the nth stage, the nth charging cut-off current of the battery in the constant voltage charging stage in the charging and discharging circulation of the nth stage is adjusted to be the first current so as to reduce the charging and discharging capacity of the battery and reduce the capacity saturation of the battery, thereby reducing the risk of side reaction of the battery and being beneficial to prolonging the circulation life of the battery.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

Fig. 1 is a schematic diagram of an application scenario provided in an embodiment of the present application;

fig. 2 is a flowchart of a charging method for a battery according to an embodiment of the present disclosure;

fig. 3 is a flowchart for determining n phases of charge and discharge cycles according to an embodiment of the present disclosure;

fig. 4 is a flowchart of a charging method for a battery according to another embodiment of the present disclosure;

fig. 5 is a flowchart of a charging method for a battery according to another embodiment of the present disclosure;

fig. 6 is a flowchart of a method for charging a battery according to another embodiment of the present disclosure;

fig. 7 is a schematic structural diagram of a charging device for a battery according to an embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a battery charging apparatus according to another embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments.

For the convenience of understanding, an application scenario applicable to the present application is first described, and as shown in fig. 1, the application scenario includes an electric vehicle 11 and a charging pile 12. A battery 111 is provided in the electric vehicle 11, and the battery 111 can be used to supply power to a load of the electric vehicle 11. The battery pack 11 includes at least one cell 1111 and a battery management system 1112. The battery cell 1111 and the battery management system 1112 may be connected by a wire harness, where the wire harness includes a data acquisition wire harness and a power wire harness. The battery cell 1111 is used for charging or discharging, and may be repeatedly charged in a manner of being rechargeable cyclically. In an embodiment, the battery cell 1111 mainly includes a positive electrode plate, a negative electrode plate, a separator, an electrolyte, and a packaging bag.

A Battery Management System (BMS) 1112 can execute the charging method of the Battery in any of the embodiments of the present application. The battery management system 1112 includes a set of control systems for protecting the safety of the battery cells 1111, so as to monitor the usage status of the battery 111. For example, the battery management system 1111 can read the variation of the voltage, current, temperature, and other parameters of the battery 111 during the charging or discharging process of the battery 111, and then can control the charging or discharging process of the battery 111 in real time according to the parameters.

The battery management system 1112 and the charging pile 12 may be connected by a bus or directly, so that the battery management system 1112 and the charging pile 12 can communicate and transmit data. For example, during the charging process, the battery management system 1112 may send the charging cutoff current during the constant voltage charging phase to the charging post 12, so that the charging post 12 stops outputting the charging current when the charging current output by the charging post reaches the charging cutoff current.

It should be noted that, in this embodiment, the electric device is taken as an electric vehicle, and in other embodiments, the electric device may also be an electric motorcycle, an electric bicycle, an electric tool, an unmanned aerial vehicle, a mobile phone, a tablet computer, a personal digital assistant, a personal computer, an energy storage product, or any other suitable device.

Next, fig. 1 is merely an example of the battery 111. In other embodiments, the battery 111 may include more or less elements, or have a different configuration of elements, which is not limited by the embodiments of the present application.

Meanwhile, the battery in the embodiment of the present application may be a lithium ion battery, a lithium metal battery, a lead-acid battery, a nickel cadmium battery, a nickel hydrogen battery, a lithium sulfur battery, a lithium air battery, a sodium ion battery, or the like, which is not limited herein. In terms of scale, the battery in the embodiment of the present application may be a single battery cell, or may be a battery module or a battery pack, which is not limited herein. From the application scene, the battery can be applied to power devices such as automobiles and ships. For example, the present invention may be applied to a power automobile to supply power to a motor of the power automobile as a power source of an electric vehicle. The battery can also supply power for other electric appliances in the electric vehicle, such as an air conditioner in the vehicle, a vehicle-mounted player and the like.

Referring to fig. 2, fig. 2 is a flowchart of a battery charging method according to an embodiment of the present disclosure. The charging method of the battery comprises n stages of charge-discharge cycles, wherein n is an integer more than or equal to 3.

In the embodiment of the present application, the process from full charge to full charge is referred to as a charge-discharge cycle. The charging and discharging cycles in multiple stages are divided in the using process of the battery, so that the charging condition can be optimized according to the actual using working condition of the battery, the charging and discharging capacity is improved, the circulating capacity retention rate is further improved, and the endurance time of the battery is prolonged. Wherein each of the n stages includes at least one charge-discharge cycle.

The battery charging method comprises the following steps:

step 201: and in the charge-discharge cycle process of each stage within the (n-1) th stage, the charge cut-off current of the battery in the constant-voltage charge stage in the charge-discharge cycle of the corresponding stage is reduced in sequence.

In the embodiments of the present application, the charging process of the battery in the charging and discharging cycle of the battery includes a constant voltage charging phase, and whether to include other charging phases is not particularly limited. Meanwhile, in the constant voltage charging stage, constant voltage charging is carried out at any time, the electric quantity of the battery is higher and higher until the charging current reaches the set minimum current value, and the battery is considered to be charged completely. The minimum current value of the constant voltage charging is the charge cut-off current.

For example, in one embodiment, the charging process of the battery includes a constant current charging phase and a constant voltage charging phase. Specifically, when the battery is charged to a specified upper limit voltage in the constant current charging stage, the charging capacity of the battery does not reach the full charging capacity, continuous charging is required, and at the moment, the constant voltage charging stage is started, and charging is stopped until the charging current reaches the charging cutoff current.

In this embodiment, after dividing the charge-discharge cycle into n stages, the charge cutoff current may be sequentially reduced according to the divided n-1 stages. The n-1 phases include the 1 st phase, the 2 nd phase, the 3 rd phase … n-1 th phase, and the 1 st charge cutoff current IE of the 1 st phase ₁ 2 nd charge cutoff current IE larger than 2 nd stage ₂ 2 nd charge cutoff current IE of the 2 nd stage ₂ Off-current IE for charging 3 rd more than 3 rd stage ₃ … n-2 charge cut-off current IE at the n-2 stage _n-2 N-1 charging cutoff current IE larger than n-1 stage _n-1 . That is, the charge cutoff current of n-1 stages satisfies: IE ₁ ＞IE ₂ ＞IE ₃ …＞IE _n-1 。

In an embodiment, step 201 may be implemented by the following method: first, charge and discharge are performed in each of the n-1 th stagesIn the circulation process, n-2 adjustment quantities are set. Wherein each stage corresponds to an adjustment amount. I.e. the 1 st adjustment X is set in the 1 st stage ₁ Setting the 2 nd adjustment quantity X in the 2 nd stage ₂ … step n-2 setting the n-2 adjustment X _n-2 .1 st adjustment amount X ₁ 2 nd adjustment quantity X ₂ … n-2 adjustment X _n-2 All the above embodiments can be set according to practical application conditions, and the embodiments of the present application do not specifically limit this. And, the 1 st adjustment amount X ₁ 2 nd adjustment quantity X ₂ … n-2 adjustment X _n-2 May be the same or different, for example, in one embodiment, the 1 st adjustment amount X is adjusted ₁ 2 nd adjustment quantity X ₂ … n-2 adjustment X _n-2 Are all set to the same value for ease of calculation.

And then, calculating a difference value between the t-th charging cut-off current in the t-th stage and the adjustment amount corresponding to the t-th stage, and taking the difference value as the t + 1-th charging cut-off current in the t + 1-th stage so as to sequentially reduce the charging cut-off current when the battery is in a constant voltage charging stage in the charging and discharging cycle of the corresponding stage, wherein t is more than or equal to 1 and less than or equal to n-2. In combination with the foregoing, the charge cutoff current in each stage within the (n-1) th stage (including the (n-1) th stage) is: IE ₁ -X ₁ ＝IE ₂ ， IE ₂ -X ₂ ＝IE ₃ …IE _n-2 -X _n-2 ＝IE _n-1 。

In the embodiment, the charging cut-off current is gradually reduced according to the characteristic parameters of the battery in the use process of the battery so as to improve the charging and discharging capacity, and compared with a scheme of adopting the constant charging cut-off current in the related art, the cyclic capacity retention rate is higher and the endurance time is longer.

In one embodiment, if the charge cut-off current of the (n-1) th stage is less than the first current threshold (denoted as I) _min ) Setting the (n-1) th charge cut-off current to the first current threshold I _min To reduce the risk that the battery may be damaged due to excessive capacity saturation.

The first current threshold may be set according to an actual application, and this is not particularly limited in the embodiment of the present application. For example, in one embodiment, the first current threshold sets a minimum charge cutoff current for the battery, which is the charge cutoff current for which the battery is rated. Generally, the charging cut-off current is set to be larger than or equal to the minimum charging cut-off current in the use process of the battery, so that the risk of damaging the battery is reduced, and the service life of the battery is prolonged.

As described above, the n-1 st charge off current satisfies IE _n-2 -X _n-2 ＝IE _n-1 In this embodiment, the n-1 th charge cutoff current should also satisfy IE _n-1 ≥I _min . In general, if IE _n-1 ≥I _min Setting the n-1 th charge cutoff current to IE _n-1 (ii) a If IE _n-1 ＜I _min Then can be adjusted by X _n-2 So that IE _n-1 ＝I _min At this time, the charge cut-off current of the n-1 th charge is I _min 。

Step 202: and during the charge-discharge cycle of the nth stage, adjusting the nth charge cutoff current of the battery in the constant voltage charge stage in the charge-discharge cycle of the nth stage to the first current.

Wherein the first current is not less than the 1 st charge cut-off current (IE) of the battery in the 1 st stage _n ) Greater than or equal to the 1 st charge cut-off current. The charge cut-off current of n stages can be satisfied by combining the above embodiments: IE _n ≥IE ₁ ＞IE ₂ ＞IE ₃ …＞IE _n-1 。

Therefore, in this embodiment, during the charging and discharging cycle of the nth stage, the nth charging cut-off current is adjusted to the first current to reduce the charging and discharging capacity of the battery, so that the capacity saturation of the battery can be reduced, the risk of side reaction of the battery can be reduced, and the cycle life of the battery can be prolonged.

In summary, in the embodiment of the present application, n stages of charge and discharge cycles are determined first. And then, the charging cut-off current is sequentially reduced in the first n-1 stages to improve the charging and discharging capacity, so that the endurance time of the battery is prolonged. And finally, directly adjusting the nth stage to be more than or equal to the 1 st charging cut-off current of the 1 st stage so as to reduce the charge and discharge capacity of the battery and reduce the risk of side reaction of the battery, thereby prolonging the cycle life of the battery.

In one embodiment, the method for charging a battery further comprises the process of determining n stages of charge and discharge cycles of the battery. As shown in fig. 3, the method further comprises the steps of:

step 301: and acquiring characteristic parameters of the battery in each charge and discharge cycle process.

Step 302: and determining the charge-discharge cycles of the battery in n stages according to the characteristic parameters.

The characteristic parameters are parameters which can reflect the actual use working conditions of the battery in the charging or discharging process of the battery, such as the voltage, the current or the temperature of the battery. Then, after the characteristic parameters are obtained, charge and discharge cycles of n stages can be divided according to the characteristic parameters.

In an embodiment, the specific implementation process of determining the charge and discharge cycles of the n stages of the battery according to the characteristic parameters in step 302 is as follows: when it is in (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) When the characteristic parameter of the charge-discharge cycle process meets a first condition, if m is more than or equal to 1 and less than n-1, the (A) th cycle is started ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) A charge-discharge cycle and the (A) th cycle ₁ +A ₂ +A ₃ …+A _m ) Determining a charge-discharge cycle between the charge-discharge cycles as a charge-discharge cycle of the mth stage; if m is n-1, the second one (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) A charge-discharge cycle and the (A) th cycle ₁ +A ₂ +A ₃ … +A _m ) Determining the charge-discharge cycle between the charge-discharge cycles as the m-stage charge-discharge cycle, and determining the (A) -th stage ₀ +A ₁ +A ₂ +A ₃ …+A _m ) The charge and discharge cycles and thereafter are determined as the charge and discharge cycles of the m +1 th stage to determine the charge and discharge cycles of the n stages of the battery.

Wherein m is more than or equal to 1 and less than or equal to n-1, A ₁ 、A ₂ 、A ₃ …A _m Are all integers greater than 0, and A ₀ ＝1。A ₁ 、 A ₂ 、A ₃ …A _m The values in (a) may be the same or different, and this is not particularly limited in the embodiment of the present application.

In one embodiment, a is 3 or n ₀ ＝1，A ₁ ＝100，A ₂ For example, 200. If m is 1, in which case 1. ltoreq. m < n-1, then when A is ₀ Characteristic parameters and A in the course of each charge-discharge cycle ₁ When the characteristic parameter of each charge-discharge cycle process meets a first condition, the A < th > is set ₀ Charge and discharge cycles with respect to item A ₁ The charge-discharge cycle between the charge-discharge cycles was determined as the charge-discharge cycle of the 1 st stage. At this time, the charge and discharge cycle of the 1 st stage includes a total of 100 charge and discharge cycles between the 1 st charge and discharge cycle and the 100 th charge and discharge cycle.

When m is 2, in which case m is n-1, then the (a) th group ₀ +A ₁ ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ ) When the characteristic parameter of each charge-discharge cycle process satisfies the first condition, firstly, the first step (A) ₀ +A ₁ ) A charge-discharge cycle and the (A) th cycle ₁ +A ₂ ) The charge-discharge cycle between the charge-discharge cycles is determined as the charge-discharge cycle of the 2 nd stage. At this time, the charge and discharge cycle of the 2 nd stage includes a total of 200 charge and discharge cycles between the 101 st charge and discharge cycle to the 300 th charge and discharge cycle.

Then, the first step (A) is added ₀ +A ₁ +A ₂ ) A charge-discharge cycle and the following (A) ₀ +A ₁ +A ₂ ) The charge-discharge cycle after the charge-discharge cycle was determined as the charge-discharge cycle of the 3 rd stage. In this case, the charge/discharge cycle at the 3 rd stage includes the 301 rd charge/discharge cycle and the following charge/discharge cycles, that is, the 301 rd charge/discharge cycle and the 302 th charge/discharge cycle …, and the charge/discharge cycle at the 3 rd stage is performed until the end of the life of the battery.

In summary, in this embodiment, the usage process of the battery includes 3 phases of charge and discharge cycles, where the charge and discharge cycle in phase 1 includes the 1 st charge and discharge cycle to the 100 th charge and discharge cycle, the charge and discharge cycle in phase 2 includes the 101 st charge and discharge cycle to the 300 th charge and discharge cycle, and the charge and discharge cycle in phase 3 includes the 301 rd charge and discharge cycle and the following charge and discharge cycle.

In this embodiment, the 1 st charge-discharge cycle is the first charge-discharge cycle of the battery charged by the charging method provided in the embodiments of the present application. The first charge-discharge cycle may be a charge-discharge cycle when the battery is used for the first time, or may be a first charge-discharge cycle when the battery that has undergone multiple charge-discharge cycles starts to be charged by using the charging method provided in the embodiment of the present application, which is not limited in the embodiment of the present application.

Meanwhile, the first condition may be set according to an actual situation, which is not specifically limited in the embodiment of the present application, for example, in an embodiment, the first condition may be set according to a magnitude relationship between the characteristic parameters.

In one embodiment, the characteristic parameter includes a charge temperature change amount of the battery during a charge/discharge cycle, a discharge temperature change amount of the battery during a charge/discharge cycle, a charge time of the battery during a charge/discharge cycle, or a discharge time of the battery during a charge/discharge cycle, and the second parameter is (a) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) The first condition that the characteristic parameters of the charge-discharge cycle process meet is as follows: the first (A) ₁ +A ₂ +A ₃ …+A _m ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) The difference value of the characteristic parameters in the charge and discharge cycle process is not less than a first difference threshold value.

The first difference threshold may be a preset value, or a value automatically generated according to the characteristic parameter, and may specifically be set according to an actual application situation, which is not specifically limited in the embodiment of the present application. For example, in an embodiment where the characteristic parameter is the amount of change in the charging temperature of the battery during a charge-discharge cycle, the first difference threshold may be set to 2 ℃. As another example, in another embodiment, where the characteristic parameter is a charge time of the battery during a charge-discharge cycle, the first difference threshold may be set to 2 minutes.

In this embodiment, the charging temperature variation amount of the battery during the charge and discharge cycle is a difference between the maximum temperature of the battery during the charge of the battery in one charge and discharge cycle and an initial temperature, wherein the initial temperature is a temperature of the battery at the time of starting the charge. The discharge temperature variation of the battery in the charge and discharge cycle process is the difference between the maximum temperature of the battery and the initial temperature in the discharge process of one charge and discharge cycle of the battery, wherein the initial temperature is the temperature of the battery at the beginning of discharge. The charging time of the battery in the charging and discharging cycle process is the time length from the state that the electric quantity of the battery is exhausted to the state that the battery is fully charged in the charging process of one charging and discharging cycle of the battery. The discharge time of the battery in the charge-discharge cycle process is the time length from a fully charged state to a state in which the electric quantity is exhausted in the discharge process of the battery in one charge-discharge cycle.

In one embodiment, a is still equal to 3, n ₀ ＝1，A ₁ ＝100，A ₂ The description will be given with reference to 200 as an example. Meanwhile, taking the characteristic parameter as the charging temperature variation of the battery in the charging and discharging cycle process as an example, and the specific implementation process of the discharging temperature variation, the charging time or the discharging time is similar to the charging temperature variation, which is within the range easily understood by those skilled in the art and will not be described herein again.

In this embodiment, when the characteristic parameter is the amount of change in the charging temperature of the battery during the charge-discharge cycle, the amount of change in the charging temperature during the 1 st charge-discharge cycle (denoted as T) ₁ ) And the amount of change in charging temperature during the 100 th charge-discharge cycle (denoted as T) ₁₀₀ ) Is not less than a first difference threshold (denoted as D) ₁ ) (ii) a Change in charging temperature during the 101 th charge-discharge cycle (denoted as T) ₁₀₁ ) And the amount of change in charging temperature during the 300 th charge-discharge cycle (denoted as T) ₃₀₀ ) Is not less than a first difference threshold (denoted as D) ₁ )。

Specifically, if T ₁₀₀ -T ₁ ≥D ₁ Determining the charge-discharge cycle from the 1 st charge-discharge cycle to the 100 th charge-discharge cycle as the charge-discharge cycle of the 1 st stage; if T ₃₀₀ -T ₁₀₁ ≥D ₁ Then, the charge and discharge cycle between the 101 st charge and discharge cycle to the 300 th charge and discharge cycle is determined as the charge and discharge cycle of the 2 nd stage, and the 301 st charge and discharge cycle and the charge and discharge cycle after the 301 st charge and discharge cycle are determined as the charge and discharge cycle of the 3 rd stage.

Note that, in this embodiment, the difference values (including T) are used ₁₀₀ -T ₁ 、T ₃₀₀ -T ₁₀₁ Two differences) are both greater than the first difference threshold. In other embodiments, a corresponding difference threshold may be set according to each difference, for example, in an embodiment, the first condition to be satisfied is set as T ₁₀₀ -T ₁ ≥D ₁₁ And T ₃₀₀ -T ₁₀₁ ≥D ₁₂ Wherein D is ₁₁ And D ₁₂ Are different threshold values of different sizes.

In another embodiment, the characteristic parameter comprises a charge capacity or a discharge capacity of the battery during charge and discharge cycles, then (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) The first condition that the characteristic parameters of the charge-discharge cycle process meet is as follows: the first (A) ₁ +A ₂ +A ₃ …+A _m ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₀ +A ₁ +A ₂ +A ₃ … +A _m-1 ) The ratio of the characteristic parameters of the charge-discharge cycle process is not more than a first ratio threshold.

The first ratio threshold may be a preset value, or a value automatically generated according to the characteristic parameter, and may specifically be set according to an actual application situation, which is not specifically limited in the embodiment of the present application. For example, in one embodiment, where the characteristic parameter is the charge capacity of the battery during a charge-discharge cycle, the first ratio threshold may be set to 98%.

In this embodiment, the charge capacity of the battery during a charge-discharge cycle is the amount of charge that the battery charges from a depleted state to a fully charged state during a charge-discharge cycle of the battery. The discharge capacity of the battery in the process of charge and discharge cycles is the electric quantity output by the battery from a fully charged state to a state in which the electric quantity is exhausted in the discharge process of one charge and discharge cycle.

In one embodiment, a is still equal to 3, n ₀ ＝1，A ₁ ＝100，A ₂ The description will be given with reference to 200 as an example. Meanwhile, taking the characteristic parameter as the charging capacity of the battery in the charging and discharging cycle process as an example, the specific implementation process of the discharging capacity is similar to the charging capacity, which is within the range easily understood by those skilled in the art, and is not described herein again.

In this example, when the characteristic parameter is the charge capacity of the battery during a charge-discharge cycle, the charge capacity during the 1 st charge-discharge cycle (denoted as C) ₁ ) And the amount of change in charging temperature during the 100 th charge-discharge cycle (denoted as C) ₁₀₀ ) Is not greater than a first ratio threshold (denoted as R) ₁ ) (ii) a Charge capacity during the 101 th charge-discharge cycle (denoted as C) ₁₀₁ ) And the charge capacity during the 300 th charge-discharge cycle (denoted as C) ₃₀₀ ) Is not greater than a first ratio threshold (denoted as R) ₁ )。

Specifically, if C ₁₀₀ /C ₁ ≤R ₁ Determining the charge-discharge cycle from the 1 st charge-discharge cycle to the 100 th charge-discharge cycle as the charge-discharge cycle of the 1 st stage; if C ₃₀₀ /C ₁₀₁ ≤R ₁ Then, the charge and discharge cycle from the 101 st charge and discharge cycle to the 300 th charge and discharge cycle is determined as the charge and discharge cycle of the 2 nd phase, and the 301 st charge and discharge cycle and the charge and discharge cycle after the 301 st charge and discharge cycle are determined as the charge and discharge cycle of the 3 rd phase.

It should be noted that, in this embodiment, the ratios (including C) are used ₁₀₀ /C ₁ 、C ₃₀₀ /C ₁₀₁ Two ratios) are both greater than the first ratio threshold. In other embodiments, a corresponding ratio threshold may be set according to each ratio, for example, in one embodiment, the first condition to be satisfied is set as C ₁₀₀ /C ₁ ≤R ₁₁ And C ₃₀₀ /C ₁₀₁ ≤R ₁₂ Wherein R is ₁₁ And R ₁₂ Are ratio thresholds of different sizes.

In another embodiment, the specific implementation process of determining the charge and discharge cycles of the n stages of the battery according to the characteristic parameters in step 302 is as follows: when it is in (B) ₁ +B ₂ +B ₃ …+B _k ) When the characteristic parameter of the charge-discharge cycle process meets a second condition, if k is more than or equal to 1 and less than n-1, the (B) th cycle is carried out ₀ +B ₁ +B ₂ +B ₃ … +B _k-1 ) A charge-discharge cycle and the (B) th cycle ₁ +B ₂ +B ₃ …+B _k ) Determining the charge-discharge cycle among the charge-discharge cycles as the charge-discharge cycle of the kth stage; if k is n-1, the (B) th group is substituted ₀ +B ₁ +B ₂ +B ₃ …+B _k-1 ) A charge-discharge cycle and the (B) th cycle ₁ +B ₂ +B ₃ …+B _k ) Determining a charge-discharge cycle between charge-discharge cycles as a charge-discharge cycle of the kth stage, and determining the (B) th stage ₀ +B ₁ +B ₂ +B ₃ …+B _k ) The charge and discharge cycles and the following charge and discharge cycles are determined as the charge and discharge cycles of the k +1 th stage so as to determine the charge and discharge cycles of the n stages of the battery.

Wherein k is more than or equal to 1 and less than or equal to n-1, B ₁ 、B ₂ 、B ₃ …B _k Are all integers greater than 0, and B ₀ ＝1。B ₁ 、 B ₂ 、B ₃ …B _k The values in (b) may be the same or different, and this is not particularly limited in this embodiment of the present application.

In one embodiment, n is 3, and B is ₀ ＝1，B ₁ ＝B ₂ For example 100. If k is 1, in which case 1. ltoreq. k < n-1, then the B-th radical ₁ When the characteristic parameter in the charge-discharge cycle process meets a second condition, the B th ₀ Charging and dischargingCirculation and B ₁ The charge-discharge cycle between the charge-discharge cycles was determined as the charge-discharge cycle of the 1 st stage. At this time, the charge and discharge cycle of the 1 st stage includes a total of 100 charge and discharge cycles between the 1 st charge and discharge cycle and the 100 th charge and discharge cycle.

When k is 2, in which case k is n-1, the (B) th group ₁ +B ₂ ) When the characteristic parameter of each charge-discharge cycle process satisfies the second condition, firstly, the second condition (B) ₀ +B ₁ ) A charge-discharge cycle and the (B) th cycle ₁ +B ₂ ) The charge-discharge cycle between the charge-discharge cycles is determined as the charge-discharge cycle of the 2 nd stage. At this time, the charge and discharge cycle of the 2 nd stage includes a total of 100 charge and discharge cycles between the 101 st charge and discharge cycle to the 200 th charge and discharge cycle.

Then, the second step (B) ₀ +B ₁ +B ₂ ) A charge-discharge cycle and the (B) th cycle ₀ +B ₁ +B ₂ ) The charge-discharge cycle after the charge-discharge cycle was determined as the charge-discharge cycle of the 3 rd stage. In this case, the charge/discharge cycle at the 3 rd stage includes the 201 st charge/discharge cycle and the following charge/discharge cycles, that is, the 201 st charge/discharge cycle and the 202 nd charge/discharge cycle …, and the charge/discharge cycle at the 3 rd stage is performed until the end of the life of the battery.

In summary, in this embodiment, the usage process of the battery includes 3 phases of charge and discharge cycles, where the charge and discharge cycle in phase 1 includes the 1 st charge and discharge cycle to the 100 th charge and discharge cycle, the charge and discharge cycle in phase 2 includes the 101 st charge and discharge cycle to the 200 th charge and discharge cycle, and the charge and discharge cycle in phase 3 includes the 201 st charge and discharge cycle and the following charge and discharge cycles.

Similarly, in this example, the 1 st charge-discharge cycle is the first charge-discharge cycle of the battery that is charged using the charging method provided in the examples of the present application. The first charge-discharge cycle may be a charge-discharge cycle when the battery is used for the first time, or may be a first charge-discharge cycle when the battery that has undergone multiple charge-discharge cycles starts to be charged by using the charging method provided in the embodiment of the present application, which is not limited in the embodiment of the present application.

In addition, the second condition may be set according to actual situations, which is not specifically limited in the embodiments of the present application, for example, in an embodiment, the second condition may be set according to the size of the characteristic parameter.

In one embodiment, the characteristic parameter includes a charging current of the battery during a charge-discharge cycle, a discharging current of the battery during a charge-discharge cycle, or an ambient temperature detected by the battery during a charge-discharge cycle, and (B) th ₁ +B ₂ +B ₃ …+B _k ) The second condition that the characteristic parameters of the charge-discharge cycle process meet is as follows: the (B) th ₁ +B ₂ +B ₃ …+B _k ) The characteristic parameter during each charge-discharge cycle is within a first variation range threshold.

The first variation range threshold may be a preset value, or may also be a value automatically generated according to the characteristic parameter, and specifically may be set according to an actual application situation, which is not specifically limited in the embodiment of the present application. For example, in one embodiment, the characteristic parameter is a charging current of the battery during a charge-discharge cycle, and the first variation range threshold is set to [0.001A, a rated current of the battery ]. As another example, in another embodiment, the characteristic parameter is an ambient temperature detected by the battery during a charge-discharge cycle, and the first variation range threshold is set to [0, 25 ℃).

In this embodiment, the charging current of the battery during the charge-discharge cycle is the current charged by the battery during the charge process of one charge-discharge cycle from a state in which the battery is depleted to a state in which the battery is fully charged. The discharge current of the battery in the process of charge and discharge cycles is the current output by the battery in the process from a fully charged state to a state of exhausted electric quantity in the discharge process of one charge and discharge cycle. The ambient temperature detected by the battery in the charging and discharging cycle process is the ambient temperature detected by the testing equipment arranged in the battery in one charging and discharging cycle.

In one embodiment, B is still equal to 3 as n ₀ ＝1，B ₁ ＝B ₂ The description will be given by way of example with 100. Meanwhile, charging the battery by using the characteristic parametersThe charging current of the discharging cycle process is taken as an example, and the specific implementation process of the discharging current or the ambient temperature detected by the battery is similar to the charging current, which is within the scope easily understood by those skilled in the art and will not be described herein.

In this embodiment, when the characteristic parameter is the charging current of the battery during a charge-discharge cycle, the charging current during the 100 th charge-discharge cycle (denoted as charging current I) ₁₀₀ ) Is always in the first variation range threshold (marked as [ R ] _min ，R _max ]) Internal; charging current during the 200 th charging and discharging cycle (denoted as charging current I) ₂₀₀ ) Is always in the first variation range threshold (marked as [ R ] _min ，R _max ]) And (4) the following steps.

Specifically, if the charging current I ₁₀₀ Is not more than R _max And a charging current I ₁₀₀ Is not less than R _min Determining the charge-discharge cycle from the 1 st charge-discharge cycle to the 100 th charge-discharge cycle as the charge-discharge cycle of the 1 st stage; if the charging current I ₂₀₀ Is not more than R _max And a charging current I ₂₀₀ Is not less than R _min Then, the charge/discharge cycle between the 101 st charge/discharge cycle and the 200 th charge/discharge cycle is determined as the charge/discharge cycle of the 2 nd stage, and the 201 st charge/discharge cycle and the charge/discharge cycle after the 201 st charge/discharge cycle are determined as the charge/discharge cycle of the 3 rd stage.

In this embodiment, each charging current (including the charging current I) is used ₁₀₀ Charging current I ₂₀₀ Two charging currents) are both within the first variation range threshold. In other embodiments, a corresponding variation range threshold may be set according to each charging current, for example, in an embodiment, the second condition to be satisfied is set as the charging current I respectively ₁₀₀ At [ R ] _min1 ，R _max1 ]Internal and charging current I ₂₀₀ At [ R ] _min2 ，R _max2 ]Wherein [ R ] _min1 ， R _max1 ]And [ R _min2 ，R _max2 ]The range threshold is different in size.

In the above embodiments, only a single characteristic parameter is used to determine the charge and discharge cycles of the n stages of the battery. In other embodiments, at least two characteristic parameters in the above embodiments may be combined to determine the charge and discharge cycles of the battery in n stages, so as to reduce the probability of misjudgment and improve the accuracy. For example, in one embodiment, the charge-discharge cycle of n stages of the battery is determined by combining two characteristic parameters, namely the charge temperature variation and the charge time of the battery during the charge-discharge cycle.

In one embodiment, as shown in fig. 4, the characteristic parameter is a charging temperature variation of the battery during a charging and discharging cycle, and the usage of the battery is divided into 4 stages of charging and discharging cycles according to the charging temperature variation. The specific process is as follows:

firstly, a charge-discharge cycle of the 1 st stage is started, and the charge temperature variation T in the 1 st charge-discharge cycle is obtained ₁ With charge cutoff current IE 1 ₁ . Continuing to perform charge-discharge cycle, and at A ₁ A is detected during each charge-discharge cycle ₁ Charging temperature variation during each charging and discharging cycle

And T ₁ The difference between the first and second threshold values is not less than a first difference threshold value D ₁ Then, the charge-discharge cycle in stage 1 is ended.

Then, in A ₁ Decreasing the charge cut-off current to the 2 nd charge cut-off current IE during +1 charge-discharge cycles ₂ And entering the charge-discharge cycle of the 2 nd stage, and the charge cutoff current of the charge-discharge cycle of the 2 nd stage is maintained at IE ₂ . Wherein, IE ₂ According to IE ₁ And 1 st adjustment amount X ₁ The difference between them is determined. Continuing to perform charge-discharge cycle, and at A ₁ +A ₂ A is detected during each charge-discharge cycle ₁ +A ₂ Charging temperature variation during each charging and discharging cycle

And

the difference between the first and second threshold values is not less than a first difference threshold value D ₁ Then, the charge-discharge cycle in the 2 nd stage is ended.

Then, at the A ₁ +A ₂ Decreasing the charge cut-off current to the 3 rd charge cut-off current IE during +1 charge-discharge cycles ₃ And entering into charge-discharge cycle of 3 rd stage, and keeping off-charge current of charge-discharge cycle of 3 rd stage at IE ₃ . Wherein, IE ₃ According to IE ₂ And 2 nd adjustment amount X ₂ The difference between them is determined. Continuing to perform charge-discharge cycle, and at A ₁ +A ₂ +A ₃ A is detected during each charge-discharge cycle ₁ +A ₂ +A ₃ Charging temperature variation during each charging and discharging cycle

And

when the difference between the first and second phases is not less than the first difference threshold D1, the charge/discharge cycle of the 3 rd phase is ended.

Finally, in the A ₁ +A ₂ +A ₃ In the +1 charge/discharge cycles, the charge cutoff current is adjusted to the first current, and the charge/discharge cycle is advanced to the 4 th stage and is maintained as the charge/discharge cycle of the 4 th stage. A (A) of ₁ +A ₂ +A ₃ The 4 th charge cut-off current IE is the charge cut-off current reduced in +1 charge-discharge cycles ₄ And IE ₄ ≥IE ₁ The charge cutoff current of the charge-discharge cycle in the 4 th stage is kept to IE ₄ 。

It should be noted that, in other embodiments, the specific implementation process of the discharge temperature variation, the charge time, or the discharge time is similar to the charge temperature variation, which is within the range easily understood by those skilled in the art, and is not described herein again.

In one embodiment, as shown in fig. 5, the characteristic parameter is the charge capacity of the battery during the charge and discharge cycle, and the usage of the battery is divided into 4 stages of charge and discharge cycles according to the charge capacity. The specific process is as follows:

firstly, a charge-discharge cycle of the 1 st stage is started, and the charge capacity C in the 1 st charge-discharge cycle process is obtained ₁ With charge cutoff current IE 1 ₁ . Continuing to execute charge-discharge cycle, and detecting A ₁ Charge capacity during a charge-discharge cycle

And C ₁ Is not greater than a first ratio threshold R ₁ Then, the charge-discharge cycle in stage 1 is ended.

And with

The difference between the two is not more than a first ratio threshold value R ₁ Then, the charge-discharge cycle in the 2 nd stage is ended.

Then, at the A ₁ +A ₂ Decreasing the charge cut-off current to the 3 rd charge cut-off current IE during +1 charge-discharge cycles ₃ And entering into charge-discharge cycle of 3 rd stage, and keeping off-charge current of charge-discharge cycle of 3 rd stage at IE ₃ . Wherein, IE ₃ According to IE ₂ And 2 nd adjustment amount X ₂ The difference between them is determined. Continue to perform charge-discharge cycle and atA (A) of ₁ +A ₂ +A ₃ A is detected during each charge-discharge cycle ₁ +A ₂ +A ₃ Charging temperature variation during each charging and discharging cycle

And

the difference between the two is not more than a first ratio threshold value R ₁ Then, the charge-discharge cycle in the 3 rd stage is ended.

It should be noted that, in other embodiments, the specific implementation process of the discharge capacity is similar to the charge capacity, which is within the range easily understood by those skilled in the art, and is not described herein again.

In one embodiment, as shown in fig. 6, the characteristic parameter is a charging current of the battery during a charging and discharging cycle, and the using process of the battery is divided into 4 stages of charging and discharging cycles according to the charging current. The specific process is as follows:

first, a charge-discharge cycle of the 1 st stage is started to obtain the 1 st charge cut-off current IE ₁ . Continuously executing charge-discharge cycle, and detecting A ₁ Charging current I during each charging and discharging cycle _A1 Is always in the first variation range R _min ，R _max ]In this step, the charge-discharge cycle in the 1 st stage is completed.

Then, in A ₁ Decreasing the charge cut-off current to the 2 nd charge cut-off current IE during +1 charge-discharge cycles ₂ And entering into charge-discharge cycle of stage 2 and in stage 2The charge cutoff current of the 2-stage charge-discharge cycle is kept to IE ₂ . Wherein, IE ₂ According to IE ₁ And 1 st adjustment amount X ₁ The difference between them is determined. Continuing to perform charge-discharge cycle, and at A ₁ +A ₂ A is detected during each charge-discharge cycle ₁ +A ₂ Charging current during a charging and discharging cycle

And always in the first variation range [ R ] _min ，R _max ]And (4) finishing the charge-discharge cycle in the 2 nd stage.

Then, at the A ₁ +A ₂ Decreasing the charge cut-off current to the 3 rd charge cut-off current IE at +1 charge-discharge cycles ₃ And entering into charge-discharge cycle of 3 rd stage, and keeping off-charge current of charge-discharge cycle of 3 rd stage at IE ₃ . Wherein, IE ₃ According to IE ₂ And 2 nd adjustment amount X ₂ The difference between them is determined. Continuing to perform charge-discharge cycle, and at A ₁ +A ₂ +A ₃ A is detected during each charge-discharge cycle ₁ +A ₂ +A ₃ Charging current during a charging and discharging cycle

Is always in the first variation range R _min ，R _max ]And (4) finishing the charge-discharge cycle in the 3 rd stage.

It should be noted that, in other embodiments, the specific implementation process of the discharging current or the ambient temperature detected by the battery is similar to the charging current, which is within the scope easily understood by those skilled in the art and is not described herein again.

In one embodiment, the charge-discharge cycle of the battery can be tested to determine that the charging method provided by the application can improve the capacity retention rate. And the characteristic parameter includes a charging temperature variation of the battery in the charging and discharging processes is taken as an example. The specific implementation process is as follows:

in the first step, the cell is left to stand for 5 minutes, i.e. the cell is kept neither charged nor discharged for 5 minutes. In the second step, the cell was discharged to 3V at a current of 0.5C. Third, the cell was allowed to stand for 5 minutes. Fourthly, charging the battery to 4.2V by 3C current, then charging the battery to 4.3V by 2C current, then charging the battery to 1.5C by constant voltage, and finally charging the battery to 0.2C by constant voltage. And step five, standing the battery for 5 minutes. And sixthly, discharging the battery to 3V at the current of 0.5C. At this time, one charge and discharge cycle is completed every time the third step to the sixth step are performed, and the charge cut-off current is 0.2C. And continuously and repeatedly executing the third step to the sixth step. And in the 300 th charge-discharge cycle, the difference value between the charge temperature variation in the 1 st charge-discharge cycle and the charge temperature variation in the 300 th charge-discharge cycle is not less than a first difference threshold value. At this time, the execution of the third step to the sixth step is ended, and the execution of the seventh step is started.

Seventh, the cell was allowed to stand for 5 minutes. And step eight, charging the battery to 4.2V by using a current of 3C, then charging the battery to 4.3V by using a current of 2C, then charging the battery to 1.5C by using a constant voltage, and finally charging the battery to 0.1C by using a constant voltage. Ninth, the cell was allowed to stand for 5 minutes. In the tenth step, the battery is discharged to 3V with a current of 0.5C. At this time, one charge and discharge cycle is completed every time the seventh step to the tenth step are performed, and the charge cut-off current is 0.1C, i.e., the charge cut-off current is reduced. And continuously and repeatedly executing the seventh step to the tenth step. In the 501 th charge-discharge cycle (including the 300 charge-discharge cycles described above), the difference between the charge temperature variation during the 501 th charge-discharge cycle and the charge temperature variation during the 700 th charge-discharge cycle is not less than the first difference threshold. At this time, execution of the seventh step to the tenth step is ended, and execution of the eleventh step is started.

In the tenth step, the cell was allowed to stand for 5 minutes. The twelfth step, the battery is charged to 4.2V with 3C current, then to 4.3V with 2C current, then to 1.5C with constant voltage, and finally to 0.05C with constant voltage. In the thirteenth step, the cell was left to stand for 5 minutes. In the fourteenth step, the battery is discharged to 3V at a current of 0.5C. At this time, one charge and discharge cycle is completed every time the tenth to fourteenth steps are performed, and the charge cut-off current is 0.05C, i.e., the charge cut-off current is lowered. And continuously and repeatedly executing the eleventh step to the fourteenth step. And in the 701 th charge and discharge cycle, the difference value between the charge temperature variation in the 701 th charge and discharge cycle and the charge temperature variation in the 900 th charge and discharge cycle is not less than a first difference threshold value. At this time, execution of the eleventh to fourteenth steps is ended, and execution of the fifteenth step is started.

Fifteenth, the cell was left to stand for 5 minutes. Sixthly, the battery is charged to 4.2V by 3C current, then the battery is charged to 4.3V by 2C current, then the battery is charged to 1.5C by constant voltage, and finally the battery is charged to 0.2C by constant voltage. Seventeenth, the battery was left standing for 5 minutes. Eighteenth step, the battery was discharged to 3V with a current of 0.5C. At this time, one charge and discharge cycle is completed every time the tenth to fourteenth steps are performed, and the charge cut-off current is 0.2C, i.e., the charge cut-off current is adjusted to be equal to the charge cut-off current at the time of performing the fourth step. And continuously and repeatedly executing the fifteenth step to the eighteenth step. Meanwhile, the capacity retention rate of the battery is tested in real time in the testing process.

In this embodiment, the charge and discharge cycle includes 4 stages in total, wherein the 1 st stage corresponds to the third step to the sixth step being repeatedly performed, the 2 nd stage corresponds to the seventh step to the tenth step being repeatedly performed, the 3 rd stage corresponds to the eleventh step to the fourteenth step being repeatedly performed, and the 4 th stage corresponds to the fifteenth step to the eighteenth step being repeatedly performed. By testing the capacity retention rate of the battery in real time in the testing process and comparing the capacity retention rate with a scheme for keeping the charge cut-off current in the related technology, on one hand, the capacity retention rate after 500-plus 700 charge-discharge cycles can be improved by 5-10% by adopting the charging method provided by the application; on the other hand, if the capacity retention rate of the battery is reduced to 70% after a plurality of charge-discharge cycles, the charge-discharge cycles can be increased by 200-500 times by adopting the charging method provided by the application. Therefore, the charging method provided by the embodiment of the application can improve the charging and discharging capacity so as to improve the capacity retention rate, and further prolong the endurance time of the battery.

Referring to fig. 7, which shows a schematic structural diagram of a charging device for a battery according to an embodiment of the present application, a charging device 700 for a battery includes: a first adjusting module 701 and a second adjusting module 702.

The first adjusting module 701 is configured to sequentially reduce a charge cutoff current of the battery at a constant voltage charging stage in a charge-discharge cycle of the corresponding stage in a charge-discharge cycle process of each stage within the (n-1) th stage.

The second adjusting module 702 is configured to adjust an nth charging cutoff current of the battery in a constant voltage charging stage in the charging and discharging cycle of the nth stage to a first current during the charging and discharging cycle of the nth stage, where the first current is not less than a 1 st charging cutoff current of the battery in the 1 st stage.

The product can execute the method provided by the embodiment of the application shown in fig. 2, and has corresponding functional modules and beneficial effects of the execution method. For technical details that are not described in detail in this embodiment, reference may be made to the methods provided in the embodiments of the present application.

Fig. 8 is a schematic structural diagram of a charging device for a battery according to another embodiment of the present disclosure. The charging device 800 for a battery includes: at least one processor 801; and a memory 802 communicatively coupled to at least one of the processors 801, as exemplified by one of the processors 701 in FIG. 8.

The memory 802 stores instructions executable by the at least one processor 701 to cause the at least one processor 801 to perform the method of charging a battery as described above with reference to fig. 2. The processor 801 and the memory 802 may be connected by a bus or other means, such as by a bus in fig. 8.

The memory 802, which is a non-volatile computer-readable storage medium, may be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as program instructions/modules corresponding to the charging method of the battery in the embodiment of the present application, for example, the respective modules shown in fig. 7. The processor 801 executes various functional applications of the server and data processing, i.e., a charging method of a battery implementing the above-described method embodiments, by running nonvolatile software programs, instructions, and modules stored in the memory 802.

The memory 802 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to use of the data transmission apparatus, and the like. Further, the memory 802 may include high speed random access memory and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, the memory 802 optionally includes memory located remotely from the processor 801, which may be connected to a data transmission device via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

One or more modules are stored in the memory 802, and when executed by the one or more processors 801, perform the method of charging the battery in any of the method embodiments described above, e.g., perform the method steps of fig. 2 described above, implementing the functionality of the modules in fig. 7.

The product can execute the method provided by the embodiment of the application, and has the corresponding functional modules and beneficial effects of the execution method. For technical details that are not described in detail in this embodiment, reference may be made to the methods provided in the embodiments of the present application.

In other embodiments, the means for charging the battery may comprise only at least one processor. Wherein, at least one processor executes corresponding instructions to execute the above-mentioned battery charging method shown in fig. 2 and realize the functions of the modules in fig. 7.

The embodiment of the application also provides a battery management system which comprises the charging device of the battery in any embodiment of the application.

The embodiment of the application also provides a battery, which comprises a battery core and the battery management system in any embodiment of the application.

The embodiment of the application also provides electric equipment, which comprises a load and the battery in any embodiment of the application, wherein the battery is used for supplying power to the load.

Embodiments of the present application also provide a non-transitory computer-readable storage medium storing computer-executable instructions that are executed by one or more processors, for example, to perform the method steps of fig. 2 described above, to implement the functions of the modules in fig. 7.

Embodiments of the present application further provide a computer program product comprising a computer program stored on a non-volatile computer-readable storage medium, the computer program comprising program instructions that, when executed by a computer, cause the computer to perform the method for charging a battery in any of the above-described method embodiments, for example, to perform the method steps of fig. 2 described above, to implement the functions of the modules in fig. 7.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; within the context of the present application, where technical features in the above embodiments or in different embodiments may also be combined, the steps may be implemented in any order and there are many other variations of the different aspects of the present application described above which are not provided in detail for the sake of brevity; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A charging method of a battery comprises n stages of charge-discharge cycles, wherein n is an integer more than or equal to 3, and the charging method comprises the following steps:

in the charge-discharge cycle process of each stage within the (n-1) th stage, the charge cut-off current of the battery at the constant voltage charge stage in the charge-discharge cycle of the corresponding stage is reduced in sequence;

and during the charging and discharging circulation of the nth stage, adjusting the nth charging cut-off current of the battery in the constant voltage charging stage in the charging and discharging circulation of the nth stage to be a first current, wherein the first current is not less than the 1 st charging cut-off current of the battery in the 1 st stage.

2. The method of claim 1, further comprising:

acquiring characteristic parameters of the battery in each charge and discharge cycle process;

and determining the charge-discharge cycles of the battery in n stages according to the characteristic parameters.

3. The method according to claim 2, wherein said determining n-stage charge-discharge cycles of said battery according to said characteristic parameter comprises:

when it is in (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) When the characteristic parameter of the charge-discharge cycle process meets the first condition,

if m is more than or equal to 1 and less than n-1, the (A) th layer is added ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) A charge-discharge cycle and the (A) th cycle ₁ +A ₂ +A ₃ …+A _m ) Determining a charge-discharge cycle between the charge-discharge cycles as a charge-discharge cycle of the mth stage;

if m is n-1, the (A) th group is substituted ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) A charge-discharge cycle and the (A) th cycle ₁ +A ₂ +A ₃ …+A _m ) Determining the charge-discharge cycle between charge-discharge cycles as the m-th stage charge-discharge cycle, and determining the (A) -th stage ₀ +A ₁ +A ₂ +A ₃ …+A _m ) Determining the charge-discharge cycle of the m +1 th stage to determine the charge-discharge cycle of the n stages of the battery;

wherein A is ₁ 、A ₂ 、A ₃ …A _m Are all integers greater than 0, and A ₀ ＝1。

4. The method of claim 3, wherein the characteristic parameters comprise: the charging temperature variation, the discharging temperature variation, the charging time or the discharging time of the battery in the charging and discharging cycle process;

the first (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameters of the charge-discharge cycle process meet a first condition, which comprises the following steps:

the first (A) ₁ +A ₂ +A ₃ …+A _m ) Characteristic parameters during each charge-discharge cycle and the (A) th ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) The difference value of the characteristic parameters in the charge and discharge cycle process is not less than a first difference threshold value.

5. The method of claim 3, wherein the characteristic parameters comprise: the charge capacity or discharge capacity of the battery during charge-discharge cycles;

the first (A) ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) Characteristic parameters and the (A) th parameter during each charge-discharge cycle ₁ +A ₂ +A ₃ …+A _m ) During a charge-discharge cycleThe characteristic parameters satisfy a first condition, including:

the first (A) ₁ +A ₂ +A ₃ …+A _m ) Characteristic parameters during each charge-discharge cycle and the (A) th ₀ +A ₁ +A ₂ +A ₃ …+A _m-1 ) The ratio of the characteristic parameters of the charge-discharge cycle process is not more than a first ratio threshold.

6. The method of claim 2, wherein said determining n phases of charge and discharge cycles of said battery based on said characteristic parameter comprises:

when it is in (B) ₁ +B ₂ +B ₃ …+B _k ) When the characteristic parameter of the charge-discharge cycle process meets the second condition,

if k is more than or equal to 1 and less than n-1, the (B) th step is performed ₀ +B ₁ +B ₂ +B ₃ …+B _k-1 ) A charge-discharge cycle and the (B) th cycle ₁ +B ₂ +B ₃ …+B _k ) Determining the charge-discharge cycle among the charge-discharge cycles as the charge-discharge cycle of the kth stage;

if k is n-1, the (B) th group is substituted ₀ +B ₁ +B ₂ +B ₃ …+B _k-1 ) A charge-discharge cycle and the (B) th cycle ₁ +B ₂ +B ₃ …+B _k ) Determining a charge-discharge cycle between charge-discharge cycles as a charge-discharge cycle of the kth stage, and determining the (B) th stage ₀ +B ₁ +B ₂ +B ₃ …+B _k ) Determining the charge-discharge cycle of the k +1 stage to determine the charge-discharge cycle of n stages of the battery;

wherein, B ₁ 、B ₂ 、B ₃ …B _k Are all integers greater than 0, and B ₀ ＝1。

7. The method of claim 6, wherein the characteristic parameters comprise: the charging current, the discharging current or the ambient temperature detected by the battery during the charging and discharging cycle of the battery;

the first mentioned(A ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameters of the charge-discharge cycle process meet a second condition, which comprises the following steps:

the first mentioned ₁ +A ₂ +A ₃ …+A _m ) The characteristic parameter of each charge-discharge cycle process is within a first variation range threshold.

8. The method according to claim 1, wherein the sequentially decreasing the charge cutoff current when the battery is in a constant voltage charging stage in a charge and discharge cycle of a corresponding stage during the charge and discharge cycle of each stage within the n-1 th stage comprises:

setting n-2 adjustment quantities in the charge-discharge cycle process of each stage within the (n-2) th stage, wherein each stage corresponds to one adjustment quantity;

and calculating a difference value between the t-th charging cut-off current in the t-th stage and the adjustment amount corresponding to the t-th stage, and taking the difference value as the t + 1-th charging cut-off current in the t + 1-th stage so as to sequentially reduce the charging cut-off current of the battery in the constant-voltage charging stage in the charging and discharging cycle of the corresponding stage, wherein t is more than or equal to 1 and less than or equal to n-2.

9. A battery charging apparatus for managing n-stage charge-discharge cycles of said battery, comprising:

the first adjusting module is used for sequentially reducing the charge cut-off current of the battery in the constant-voltage charging stage in the charge-discharge cycle of the corresponding stage in the charge-discharge cycle process of each stage within the (n-1) th stage, wherein n is an integer more than or equal to 3;

the second adjusting module is used for adjusting the nth charging cut-off current of the battery in the constant voltage charging stage in the charging and discharging cycle of the nth stage to be a first current in the charging and discharging cycle of the nth stage, wherein the first current is not less than the 1 st charging cut-off current of the battery in the 1 st stage.

10. A battery charging apparatus, comprising:

at least one processor and a memory communicatively coupled to the at least one processor, the memory storing instructions executable by the at least one processor to enable the at least one processor to perform the charging method of any of claims 1-8.

11. A battery management system, characterized by comprising a charging device for the battery according to claim 10.

12. A battery comprising a cell and the battery management system of claim 11.

13. An electrical consumer, comprising a load and the battery of claim 12, the battery being configured to power the load.

14. A non-transitory computer-readable storage medium storing computer-executable instructions that, when executed by a charging device for a battery, cause the battery charging device to perform the charging method of any one of claims 1-8.