CN117117358A

CN117117358A - Battery processing method and battery

Info

Publication number: CN117117358A
Application number: CN202310206385.6A
Authority: CN
Inventors: 李帅; 梁家华; 李文文; 卢轮; 朱华
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2023-02-25
Filing date: 2023-02-25
Publication date: 2023-11-24
Anticipated expiration: 2043-02-25
Also published as: CN117117358B

Abstract

The embodiment of the application provides a battery processing method and a battery. In this method, after formation of the battery, the battery is reprocessed before capacity division: a new protective film (also an SEI film) which is more resistant to oxidation is obtained based on the original SEI film obtained in the formation process. Wherein, the process of reprocessing the battery comprises: and performing at least one deep discharge on the formed battery to decompose components with poor oxidation resistance in the original SEI film and generate other components. By implementing the technical scheme provided by the application, a protective film with higher oxidation resistance can be formed on the surface of the battery cathode, and the electrolyte is prevented from contacting the cathode to react and produce gas when the battery is excessively discharged, so that the safety and reliability of the battery are improved.

Description

Battery processing method and battery

Technical Field

The application relates to the field of battery manufacturing, in particular to a battery processing method and a battery.

Background

After the battery (such as a lithium battery) is subjected to formation, capacity division, encapsulation and other treatments, a finished battery can be obtained, and the use modes of the finished battery can include: is placed in an electronic device for powering the electronic device, etc.

During formation of the battery, a solid electrolyte interface film (solid electrolyte interface, SEI), abbreviated as SEI film, is formed on the negative electrode by first charging the battery. The SEI film is generated because: during the first charge, the electrolyte in the battery undergoes a reduction reaction at the negative electrode. For example, some of the components in the electrolyte undergo a reduction reaction at the graphite anode. In the subsequent use process of the finished battery, the SEI film can prevent the electrolyte from reacting with the negative electrode, so that the loss of active lithium can be reduced, and the service life of the finished battery is prolonged. The stability of the SEI film also has a great influence on the first coulombic efficiency, cycle life, reliability and safety of the battery. The more stable the stability of the SEI film, the higher the first coulombic efficiency, cycle life, reliability and safety of the battery. Among them, the stability of the SEI film may be determined by the quality, composition, strength, thickness, etc. of the SEI film.

Stability includes oxidation resistance, reduction resistance, and the like. However, the SEI film generated during the formation is inferior in oxidation resistance, and how to generate a SEI film of more oxidation resistance is worth discussing.

Disclosure of Invention

The application provides a battery processing method and a battery, which can enable the negative electrode of the battery to have a protective film with higher oxidation resistance, prevent the reaction of electrolyte and the negative electrode, and improve the safety and reliability of the battery.

In a first aspect, the present application provides a battery processing method, the method comprising: charging the battery injected with the electrolyte for the first time to perform formation to obtain a formed battery; the anode of the battery after the formation is provided with a first protective film, and the first protective film is generated by the reduction reaction of the electrolyte on the anode in the formation process; discharging the formed battery for N times, so that the voltage corresponding to the battery after each discharge is over-discharge voltage, and obtaining the battery after N times of discharge; the negative electrode in the battery after the N times of discharging is provided with a second protective film; the second protective film is obtained after the electrolyte and the negative electrode are in contact reaction to generate other components after part or all of the components in the first protective film are decomposed in the N discharging processes; the overdischarge voltage is smaller than the shutdown voltage of the battery in the using process; n is an integer greater than or equal to 1; charging the battery after the N times of discharging with a first current, so that the voltage corresponding to the charged battery is a capacity-divided voltage; the capacity-variable voltage is larger than the overdischarge voltage and smaller than the full-charge voltage; the full-charge voltage is the corresponding voltage when the charged battery continues to be fully charged.

In the above embodiment, after the battery is formed, the battery is reprocessed before capacity division: a new protective film (also an SEI film) which is more resistant to oxidation is obtained based on the original SEI film obtained in the formation process. Wherein, the process of reprocessing the battery comprises: and performing at least one deep discharge on the formed battery to decompose the components with poor oxidation resistance in the original SEI film and generate other components. By implementing the technical scheme provided by the application, a protective film with higher oxidation resistance can be formed on the surface of the battery cathode, and the electrolyte is prevented from contacting the cathode to react and produce gas when the battery is excessively discharged, so that the safety and reliability of the battery are improved.

With reference to the first aspect, in some embodiments, after charging the battery after N times of discharging with the first current, so that a voltage corresponding to the charged battery is a capacity-separable voltage, the method further includes: continuously charging the charged battery to be fully charged by a second current to obtain a fully charged battery; the second current is greater than the first current; discharging the fully charged battery, and recording the total discharged electric quantity as the capacity of the battery;

after the capacity of the battery meets the requirement, packaging the battery with the capacity meeting the requirement to obtain the target battery.

In the above embodiment, the first current is a smaller current. The battery is not suitable for charging using the current (e.g., 10A) involved in normal charging under an overdischarge condition, and may cause damage to the battery. It is therefore necessary to charge the battery in the overdischarged state to a volumetric voltage based on a smaller current (first current), the purpose of which is to activate the battery. The battery is then charged based on the current (second current) involved in normal charging to perform the capacity-dividing operation.

With reference to the first aspect, in some embodiments, discharging the formed battery N times specifically includes: the process of discharging the formed battery for N times comprises T different stages, wherein the current output by the different stages in the T stages is different when the battery is discharged, and the current output by the battery in each stage in the T stages is the same.

In the above embodiment, the N times of discharging are performed in stages, so that the battery is discharged more thoroughly, which is beneficial to the generation of the second protective film.

With reference to the first aspect, in some embodiments, discharging the formed battery N times specifically includes: each of the N discharges was performed on the battery after the formation to discharge the battery to an overdischarge voltage with the same current.

In the above embodiment, the process of discharging the battery to the overdischarge voltage to achieve the second protective film based on the first protective film can be regarded as a simulation of the decomposition of the first protective film when the battery is in the overdischarge state during use.

With reference to the first aspect, in some embodiments, charging the battery after the N times of discharging with the first current specifically includes: the process of charging the battery after the N times of discharging comprises D stages, wherein the first current used when the battery after the N times of discharging is charged in different stages in the D stages is different; the same phase of the D phases is used for charging the battery after the N times of discharging, and the first current used by the same phase is the same; the D is an integer of 2 or more.

In the above embodiments, the current levels involved in different discharge phases may be different, which increases the flexibility of the scheme.

With reference to the first aspect, in some embodiments, charging the battery after the N times of discharging with the first current specifically includes: the battery after the N times of discharge is charged with the same first current.

In the above embodiment, the battery in the over-discharge state is charged to the capacity-separable voltage based on the smaller current (first current), which is aimed at activating the battery.

In combination with the first aspect, in some embodiments, the process of discharging the formed battery N times is divided into T different phases, and the currents output by the different phases in the T phases when discharging the battery are different, and the currents output by the same phase in the T phases when discharging the battery each time are the same, which specifically includes: dividing the process of discharging the battery after formation into 2 different stages; in a first stage, discharging the formed battery to a voltage of 2.2V by a current of 0.1C to obtain a discharged battery, and then performing a first operation cycle 99 times, the first operation comprising: after 5 minutes, the battery after the last discharge is discharged again to a voltage of 2.2V by continuing to pass through 0.1C current; a second stage of performing a second operation loop 50 times, the second operation including: after 5 minutes, the battery after the last discharge was discharged again to a voltage of 1.8V by a current of 0.01C; then, a battery after 150 discharges was obtained; wherein C indicates the capacity value of the battery.

In the above embodiments, the current levels involved in different charging phases may be different, which increases the flexibility of the scheme.

With reference to the first aspect, in some embodiments, each of N discharges performed on the formed battery discharges the battery to an overdischarge voltage with a same current, and specifically includes: discharging the formed battery to a voltage of 2.2V by a current of 0.1C to obtain a battery after one discharge, and then performing a first operation cycle 99 times, the first operation comprising: after 5 minutes, the battery after the last discharge is discharged again to a voltage of 2.2V by continuing to pass through 0.1C current; then, a battery after 100 discharges was obtained; wherein C indicates the capacity value of the battery.

With reference to the first aspect, in some embodiments, each of N discharges performed on the formed battery discharges the battery to an overdischarge voltage with a same current, and specifically includes: discharging the formed battery to a voltage of 2.2V by a current of 0.1C to obtain a battery after one discharge, and then performing a first operation cycle 49 times, the first operation comprising: after 5 minutes, the battery after the last discharge is discharged again to a voltage of 2.2V by continuing to pass through 0.1C current; then, a battery after 50 discharges was obtained; wherein C indicates the capacity value of the battery.

With reference to the first aspect, in some embodiments, the battery is a battery with a full voltage equal to 4.0V-4.6V; the first current is 0.001C-5C.

In a second aspect, the present application provides a battery comprising an electrolyte and a negative electrode, wherein the battery is formed by charging the battery injected with the electrolyte for the first time to form a formed battery; the anode in the battery after the formation is provided with a first protective film; the battery after formation is subjected to N times of discharging, so that the voltage corresponding to the battery after each time of discharging is over-discharge voltage, and the battery after N times of discharging is obtained; after the decomposition of some or all of the components in the first protective film of the negative electrode in the battery after the N times of discharging, the electrolyte and the negative electrode are in contact reaction to generate other components, and then the second protective film is obtained.

In the second aspect, after the battery is formed, the battery is reprocessed before capacity division: a new protective film (also an SEI film) which is more resistant to oxidation is obtained based on the original SEI film obtained in the formation process. Wherein, the process of reprocessing the battery comprises: and performing at least one deep discharge on the formed battery to decompose the components with poor oxidation resistance in the original SEI film and generate other components. By implementing the technical scheme provided by the application, a protective film with higher oxidation resistance can be formed on the surface of the battery cathode, and the electrolyte is prevented from contacting the cathode to react and produce gas when the battery is excessively discharged, so that the safety and reliability of the battery are improved.

In a third aspect, the present application provides an electronic device, including a battery, where the battery is a battery described in the foregoing first aspect or any one of the embodiments of the first aspect.

Drawings

FIG. 1 illustrates an exemplary flow chart for obtaining a finished battery in one approach;

FIG. 2 illustrates an exemplary flow chart involved in a battery processing method in an embodiment of the application;

fig. 3 shows a schematic view of the negative electrode formation protective film 1 in the battery after formation;

FIG. 4 shows a schematic diagram of a target cell obtained under group 1 parameters;

FIG. 5 illustrates an exemplary flow chart involved in deep discharging a battery;

FIG. 6 shows a schematic diagram of a target cell obtained under group 2 parameters;

FIG. 7 shows a schematic diagram of a target cell obtained under group 3 parameters;

fig. 8 is a schematic view of a battery processing apparatus according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The terminology used in the following embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of the present application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates to the contrary. It should also be understood that the term "and/or" as used in this disclosure refers to and encompasses any or all possible combinations of one or more of the listed items.

The terms "first," "second," and the like, are used below for descriptive purposes only and are not to be construed as implying or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature, and in the description of embodiments of the application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In one embodiment of the application, the battery is subjected to formation, capacity division, packaging and other treatments to obtain a finished battery.

Fig. 1 shows an exemplary flow chart for obtaining a finished battery in one version.

For details concerning this process, reference is made to the following description of step S11 to step S13.

S11, performing formation on the battery to obtain a formed battery.

The battery formation includes: the battery injected with the electrolyte is charged for the first time to form a solid electrolyte interface film (solid electrolyte interface, SEI), abbreviated as SEI film.

It should be understood here that the voltages reached by the different batteries at the time of first charging are different. For example, when the battery is a battery of an electronic device such as a mobile phone, the voltage reached by the first charge is about 3.8V-full voltage (e.g., 4.2V, etc.).

The battery of the electronic device such as a mobile phone comprises a battery with a full charge voltage of 4.0V-4.6V, such as 4.2V, or a battery with a capacity of 1000mAh-5000mAh, such as 3000 mAh:

s12, charging and discharging the formed battery to separate the capacity, and screening out the battery with the capacity meeting the requirement.

For example, in some possible cases, the formed battery may be charged and then discharged to about the preset voltage 1 to determine the capacity of the battery, and then the battery with the capacity meeting the requirement is selected.

It should be understood herein that the preset voltage 1 may be a voltage value smaller than the shutdown voltage and close to the shutdown voltage, for example, the preset voltage 1 may be 3.0V, etc., and may also be another value, for example, 3.2V, which is not limited in the embodiment of the present application.

The capacity division includes distinguishing the batteries based on the capacity of the batteries, and determining whether the batteries are batteries with the capacity meeting the requirement. When it is determined that the capacity of the battery meets the requirement, the following step S13 is performed.

It should be understood here that the definition of capacity compliance is different for different batteries. For example, when the battery is a battery of an electronic device such as a mobile phone, the capacity meeting requirements may include that the battery has a capacity of 1000mAh-5000mAh, for example 3000mAh, or other values, for example 5500mAh, which is not limited in the embodiment of the present application.

The method for determining the capacity of the battery comprises the following steps: and fully charging the battery after formation, discharging, and recording the total discharged electric quantity as the capacity of the battery.

S13, packaging the battery meeting the requirements and the like to obtain the target battery.

The target battery can be obtained after the packaging and other treatments. The target battery can also be understood as a finished battery as referred to above.

In some possible cases, except for the encapsulation process. The method also comprises air extraction treatment and shaping treatment. The suction process may be performed before the encapsulation process is performed. In step S13, the pumping process includes: the gas formed in the formation or volumetric phase is collected in a gas pouch disposed on the cell, and the gas pouch is removed from the cell.

The target battery can be obtained by performing the above steps S11 to S13. However, the SEI film generated during the formation is inferior in oxidation resistance. In the later period, in the use process of the battery, when the battery is in an overdischarge state, the SEI film can be oxidized and decomposed. The electrolyte cannot be prevented from reacting with the negative electrode. In the case of the electrolyte reacting with the negative electrode, a gas may be generated, including but not limited to one or more of hydrogen, methane, ethane, carbon dioxide, etc. The generation of gas may cause battery failure, and some flammable and explosive gases may also deteriorate the thermal stability of the battery, so that the battery explodes, with a certain safety risk.

It should be appreciated that the foregoing references to the battery being in an over-discharged state include a state in which the battery voltage continues to drop after the battery voltage drops to the shutdown voltage of the electronic device during use. The shutdown voltage is a voltage corresponding to the shutdown time when the voltage drops to a threshold voltage in the use process of the battery, and the threshold voltage can be understood as the shutdown voltage.

It should be understood that the shutdown voltages corresponding to the different batteries during use are different, for example, when the battery is a battery of an electronic device such as a mobile phone, the shutdown voltage may be 3.0V-3.5V, for example, 3.5V, etc.

Wherein, the reasons that different batteries are in the overdischarge state in the use process are different. For example, when the battery is a battery of an electronic device such as a mobile phone. Reasons for being in an over-placed condition during use include, but are not limited to, one or more of the following.

Overdischarge cause 1: the electronic equipment is shut down due to insufficient electric quantity of the battery, the subsequent electronic equipment is not charged in a high-temperature and high-humidity environment, and the battery is still continuously discharged, so that the battery is in an overdischarge state. In this scenario, the gas generated when the electrolyte reacts with the anode may mainly include: hydrogen (H) ₂ ) Carbon monoxide (CO), carbon dioxide (CO) ₂ ) Alkane gas.

Overdischarge cause 2: the electronic device may cause a short circuit of the battery due to a drop or the like, for example, the battery outer ring diaphragm may shrink inwards to cause a short circuit. The battery is easily in an overdischarge state during use after short circuit. In this scenario, the gas generated when the electrolyte reacts with the anode may mainly include: alkane gas.

In another aspect of the embodiment of the present application, after formation of the battery, the generated SEI film may be further reprocessed before capacity division to obtain a new protective film (also referred to as an SEI film) having a higher oxidation resistance.

The SEI film generated upon formation of the battery may also be referred to as a protective film 1. The new protective film may be referred to as protective film 2.

Wherein, the process of reprocessing the generated SEI film to obtain the protection film 2 comprises the following steps: the formed battery is subjected to at least one deep discharge to decompose the components having poor oxidation resistance in the protective film 1 while generating other components, so as to obtain a protective film 2 having more oxidation resistance (oxidation resistance is better than that of the protective film 1). The component having poor oxidation resistance includes a portion having poor oxidation resistance in the protective film 1, and may be, for example, lithium alkyl carbonate. The other component is a component having poor oxidation resistance different from that decomposed in the protective film 1. That is, it is understood that the negative electrode of the battery is exposed to the decomposition site of the protective film 1, so that the electrolyte reacts with the negative electrode to form a new component, thereby obtaining the protective film 2. The protective film 2 can also be understood as: including the remaining protective film 1 and the newly formed other components.

In some possible cases, the protective film 1 may also be referred to as a first protective film, and the protective film 2 may also be referred to as a second protective film.

The deep discharging includes discharging the battery to the corresponding voltage as overdischarge voltage, which is smaller than the capacity-variable voltage and the shutdown voltage.

It should be understood here that the overdischarge voltages corresponding to the different types of batteries are different. For example, when the battery is a lithium battery, the over-discharge voltage may be 0V-2.5V, for example, 1.8V or 2.5V. Other values are possible, such as 2.8V, which is not limiting in this embodiment of the application.

The process of obtaining the protective film 2 based on the protective film 1 can be regarded as a simulation of the decomposition of the protective film 1 during use of the battery and in an overdischarged state. Before use, the components of the protective film 1 having poor oxidation resistance are decomposed in the case of deep discharge, and the protective film 2 having more oxidation resistance is produced. The protective film 2 can remain stable during use of the battery in an overdischarged state without causing oxidative decomposition of the protective film 2. Thus, the electrolyte can be prevented from reacting with the negative electrode, and the safety and reliability of the battery can be improved.

After at least one deep discharge, the deeply discharged battery is charged so that the voltage corresponding to the charged battery is the aforementioned capacity-separable voltage, thereby performing capacity separation.

And subsequently, after the treatments of capacity division, encapsulation and the like are carried out on the charged battery, the target battery can be obtained.

Fig. 2 shows an exemplary flow chart of a battery processing method according to an embodiment of the present application.

The battery processing method according to the embodiment of the present application may refer to the following description of step S101 to step S105.

S101, forming the battery to obtain a formed battery, wherein a protective film 1 is formed on the negative electrode of the formed battery.

The protective film 1 may be an SEI film formed by chemical conversion of the battery described above.

In some possible cases, the process of forming the battery may include: the battery injected with the electrolyte is charged for the first time to form the protective film 1.

In some possible cases, in particular, the battery may be placed in a formation device that satisfies the condition A1, and the first charge is performed with the current A2, where the voltage reached by the first charge is about 3.8V-full voltage (e.g., 4.5V, etc.).

The current A2 involved in the formation of the batteries may be different or the same. When the battery is a battery of an electronic device such as a mobile phone, the condition A1 includes that the surface pressure of the formation device is 0.1Mpa-5Mpa, for example 2Mpa, and the temperature is 45 ℃ to 100 ℃, for example 50 ℃. The magnitude of the current A2 may be 0.001C-5C. Wherein C represents the capacity value of the battery.

Fig. 3 shows a schematic view of the negative electrode formation protective film 1 in the battery after formation.

As shown in fig. 3, the protective film 1 covers the negative electrode, and prevents the electrolyte from contacting the negative electrode and further reacting. In one possible case, the components in the protective film 1 mainly include lithium-containing compounds. For example, component 1, component 2 and component 3 are included, and the component 1-component 3 can be lithium fluoride (LiF) and lithium oxide (Li) ₂ O), lithium carbonate (Li) ₂ CO ₃ ) Etc. Other compounds may also be included, such as polyolefins (polyoleephines) and the like.

S102, discharging the formed battery for N times, so that the voltage corresponding to the battery after each discharge is over-discharge voltage which is smaller than the capacity-separable voltage, and generating a protective film 2 on the negative electrode of the battery after N times of discharge, wherein the protective film 2 is obtained based on the protective film 1.

Each of the N discharges of the formed battery in step S102 can be understood as one deep discharge of the formed battery as described above.

The protective film 2 is understood to be a new protective film as referred to above, which is obtained by decomposing a part of the protective film 1 and generating a new component (which may be different from the decomposed component).

It should be understood here that the overdischarge voltage and the partial capacity voltage corresponding to different batteries are different. For example, when the battery is a battery of an electronic device such as a mobile phone, the capacity-variable voltage may be typically 3.0V to 3.5V, for example, 3.0V, etc. The over-discharge voltage may be 0V-2.5V, for example 1.8V or 2.5V. The embodiment of the present application is not limited thereto.

In step S102, the manner of discharging the formed battery N times includes, but is not limited to, the following manner.

Deep discharge mode 1: each of the N discharges performed on the formed battery was discharged to an overdischarge voltage (referred to as overdischarge voltage 11) with the same current (referred to as current 11). The overdischarge voltage 11 reached by the battery per discharge may be the same or different. For example, the jth overdischarge voltage 11 may be 2.2V, and the kth overdischarge voltage 11 may be 1.8V, which is not limited in the embodiment of the present application. Wherein N is an integer greater than or equal to 1. j and k are not equal and are positive integers less than N.

It should be understood here that the current 11 used by the different batteries at each discharge is different. For example, when the battery is a battery of an electronic device such as a mobile phone, the current 11 may be 0.001C-2C. Wherein C represents the capacity value of the battery.

For an exemplary case of the deep discharge pattern 1, reference may be made to the following description of step S102a and step S102b, which are not repeated here.

Deep discharge pattern 2: dividing the process of discharging the battery after formation into T different ordersSegments. Wherein, the current output when the battery is discharged in different stages in the T stages is different. In the same phase among the T phases, the current output to discharge the battery is the same (the same magnitude) each time. The current outputted by discharging the battery in the h stage of the T stages is referred to as current 2h, and the overdischarge voltage reached by discharging the battery is referred to as overdischarge voltage 2h. The overdischarge voltages used when discharging the battery at different stages may be different or the same. Wherein T is an integer greater than or equal to 2. h is an integer with a value between 1 and T. The number of times the battery is discharged in the h stage is denoted as F _h Then

Here, the description is given by taking T equal to 2 as an example. The process of discharging the formed battery N times may be divided into 2 different stages. The current involved in discharging the battery in the 1 st stage is referred to as a current 21, and the overdischarge voltage to which the battery is discharged is referred to as an overdischarge voltage 21. The current involved in discharging the battery in the 2 nd stage is referred to as current 22, and the overdischarge voltage to which the battery is discharged is referred to as overdischarge voltage 22. The current 21 and the current 22 are different, and the overdischarge voltage 21 and the overdischarge voltage 22 may be the same or different, which is not limited in the embodiment of the present application.

It should be understood here that in step S102, each of the N discharges the battery using a small current (0.001C-2C in magnitude). The discharge process can be made more stable and the duration is long, which is favorable for the generation of the protective film 2. The N-time discharge is performed for the purpose of making the protective film 2 more resistant to oxidation.

In step S102, in some possible cases, the process of discharging the formed battery N times includes: after the r-th discharge, the battery after the r-th discharge is obtained, and after the discharge interval time, the battery after the r-th discharge is discharged again to obtain the battery after the r+1th discharge. Wherein r is an integer of 1 or more and less than N. The discharge interval may be 2min-10min, for example 5min.

The purpose of setting the discharge interval time in the two discharge operations of the battery is to: the voltage of the battery obtained after the previous discharge may rise within the discharge interval time, and the discharge is performed again after the discharge interval time, so that the voltage of the battery may more easily reach the overdischarge voltage in the next discharge.

S103, charging the battery after N times of discharging, so that the voltage corresponding to the charged battery is a capacity-variable voltage.

It should be understood here that in step S103, the current (denoted as current B) used when charging is performed after N times of discharging is different for different batteries. For example, when the battery is a battery of an electronic device such as a mobile phone, the current B may be 0.001C-5C. Wherein C represents the capacity value of the battery.

In some possible cases, the current used when the battery is charged after N times of discharging in step S103 may also be referred to as a first current. That is, the aforementioned current B may also be referred to as a first current.

In some possible cases, the charging may be performed using a constant (same) current B, so that the voltage corresponding to the charged battery is a capacity-separable voltage. For example, the current B may be 2C or the like.

In other possible cases, the process of charging the battery after N discharges is divided into D stages. The current B used when charging the battery is different in different stages of the D stages. The current B used when charging the battery in the same one of the D stages is the same (the same magnitude). For example, the current B used in charging the battery in one of the D phases may be 2C, and the other phases may be a different value than 2C, such as 1.5C, etc. And D is an integer greater than or equal to 2.

S104, carrying out capacity division based on the charged battery, and determining that the capacity of the battery meets the requirement.

The voltage corresponding to the battery after charging in step S104 is a scalable voltage.

It should be understood here that the respective partial capacity voltages of the different batteries are different. For example, when the battery is a battery of an electronic device such as a mobile phone, the capacity-variable voltage may be typically 3.0V to 3.5V, for example, 3.0V, etc.

The capacity division includes distinguishing the batteries based on the capacity of the batteries, and determining whether the batteries are batteries with the capacity meeting the requirement. When it is determined that the capacity of the battery meets the requirements, the following step S105 is performed.

It should be understood here that the definition of capacity compliance is different for different batteries. For example, where the battery is a battery of an electronic device such as a cell phone, the capacity compliance may include a battery capacity of 1000mAh to 5000mAh, for example 3000mAh, or the like.

The method for determining the capacity of the battery comprises the following steps: and continuously charging the charged battery to be fully charged by the current D, discharging, and recording the total discharged electric quantity as the capacity of the battery.

In some possible cases, this current D may also be referred to as a second current. The second current may also be understood as a current involved in charging the battery after the formation in the step S12.

The current D is larger than the current B used when the battery is charged N times after the discharge in the aforementioned step S103. This is because: the voltage of the battery is not in an overdischarge state after the voltage reaches the capacity-variable voltage, and the battery can be charged with a larger current.

The term "partial volume voltage" is understood here to mean a voltage greater than the overdischarge voltage and less than the full voltage. The full-point voltage is the corresponding voltage when the battery is fully charged.

The overdischarge voltage is smaller than the shutdown voltage of the battery (target battery) during use.

S105, packaging the battery meeting the requirements and the like to obtain the target battery.

In some possible cases, except for the encapsulation process. The method also comprises air extraction treatment and shaping treatment. The suction process may be performed before the encapsulation process is performed. In step S105, the pumping process includes: the gas formed in the formation, deep discharge or capacity-division stage is collected in a gas pouch disposed on the battery, and then the gas pouch is removed from the battery.

It can also be understood that the operations performed in step S104 and step S105 include: continuously charging the charged battery to be fully charged to obtain a fully charged battery; discharging the fully charged battery, and recording the total discharged electric quantity as the capacity of the battery; and after the capacity of the battery meets the requirement, packaging the battery with the capacity meeting the requirement and the like to obtain the target battery.

It should be understood here that, by implementing the battery processing method according to the embodiment of the application, the negative electrode of the battery can be provided with the protective film (protective film 2) which is more resistant to oxidation, the effect of the reaction between the electrolyte and the negative electrode is prevented, and the safety and reliability of the battery are improved. The battery with the protective film 2 is still very resistant to oxidation and does not decompose in an overdischarge state, can effectively prevent the electrolyte from reacting with the negative electrode, and does not generate gas or generates less gas in the overdischarge state. Therefore, when the battery used by the electronic equipment is the battery with the protective film 2, the shutdown voltage of the electronic equipment can be downwards adjusted, and the whole machine endurance is improved. And in the use process of the battery, the safety can be improved, and the risk of swelling of the battery is reduced.

Based on the content of the foregoing steps S101-S105, the example 3 sets of parameters are used to implement the foregoing steps S101-S105 to obtain the target battery in the embodiment of the present application.

Fig. 4 shows a schematic diagram of the target cell obtained under the 1 st set of parameters.

Wherein the 1 st set of parameters comprises: in step S102, N is 100, the overdischarge voltage is 2.2V, and the discharge interval time is 5min. Each of the 100 discharges was discharged with a current of 0.1C. The current used when charging the battery in step S103 is 2C.

The process of obtaining the target battery based on the 1 st group parameter may refer to the following description of step S101a to step S105 a.

And S101a, performing formation on the battery to obtain a formed battery, wherein a protective film 1 is formed on the negative electrode of the formed battery.

The content related to this step S101a is the same as that related to the foregoing step S101, and reference may be made to the foregoing description of step S101, which is not repeated here.

S102a. discharging the battery to a voltage of 2.2V by a current of 0.1C to obtain a battery after one discharge, and then performing operation 1 in a cycle of 99 times, the operation 1 comprising: after 5 minutes, the battery after the last discharge was discharged again to a voltage of 2.2V by a current of 0.1C, and a battery after 100 discharges was obtained, in which a protective film 2 was formed on the negative electrode in the battery after 100 discharges, and the protective film 2 was obtained based on the protective film 1.

This step S102a can be regarded as one exemplary scenario of discharging the battery using the deep discharge mode 1.

Fig. 5 illustrates an exemplary flow chart involved in deep discharging a battery.

As shown in fig. 5, the process involved in obtaining the battery after 100 discharges may refer to the following description of step S201 to step S204.

S201. setting i=1, discharging the battery to a voltage of 2.2V by a current of 0.1C, and obtaining the battery after the ith discharge.

S202, determining whether i is equal to 100.

In the case where it is determined that i is less than 100, the following step S203 is performed to continue discharging the battery.

In the case where it is determined that i is equal to 100, the following step S204 is performed to end discharging the battery.

S203. after setting i=i+1 for 5 minutes, discharging the battery after the i-1 th discharge again to a voltage of 2.2V by a current of 0.1C, to obtain the battery after the i-1 th discharge.

S204, finishing the cyclic discharging operation of the battery to obtain a battery after 100 times of discharging, wherein a protective film 2 is generated on the negative electrode of the battery after 100 times of discharging, and the protective film 2 is obtained based on the protective film 1.

And S103a, charging the battery after 100 times of discharging through the current with the size of 2C, so that the voltage corresponding to the charged battery is a capacity-separable voltage.

After the step S102, the battery after 100 times of discharging is in an overdischarge state, and the battery after 100 times of discharging may be charged with a current having a magnitude of 2C, so that a voltage corresponding to the charged battery is a capacity-separable voltage.

It should be understood here that the current of 2C is a small current, and charging the battery after 100 times of discharging based on the current of 2C can protect the battery to the maximum. Because the battery is not suitable for charging using the current (e.g., 10A) involved in normal charging at this time, damage may be caused to the battery.

The current involved in normal charging is the charging current used in the use process of the battery.

S104a, carrying out capacity division based on the charged battery, and determining that the capacity of the battery meets the requirement.

The content related to the step S104a is the same as that related to the step S104, and the description of the step S104 is referred to and will not be repeated here.

S105a, packaging the battery meeting the requirements and the like to obtain the target battery.

The content related to this step S105a is the same as that related to the foregoing step S105, and reference may be made to the foregoing description of step S105, which is not repeated here.

Fig. 6 shows a schematic diagram of the target cell obtained under the group 2 parameters.

Wherein the group 2 parameters include: in step S102, N is 50, the overdischarge voltage is 2.2V, and the discharge interval time is 5min. Each of the 50 discharges was discharged with a current of 0.1C. The current used when charging the battery in step S103 is 2C.

The group 2 parameters differ from the group 1 parameters in that N is set to 50 times.

The process of obtaining the target battery based on the 2 nd group parameter may refer to the following description of step S101 b-step S105 b.

S101b, forming the battery to obtain a formed battery, wherein a protective film 1 is formed on the negative electrode of the formed battery.

The content related to this step S101b is the same as that related to the foregoing step S101, and reference may be made to the foregoing description of step S101, which is not repeated here.

S102b. discharging the battery to a voltage of 2.2V by a current of 0.1C to obtain a battery after one discharge, and then performing operation 1 in a cycle 49 times, the operation 1 comprising: after 5 minutes, the battery after the last discharge was discharged again to a voltage of 2.2V by a current of 0.1C, and a battery after 50 discharges was obtained, in which a protective film 2 was formed on the negative electrode in the battery after 50 discharges, and the protective film 2 was obtained based on the protective film 1.

The content related to the step S102b is similar to the content related to the step S102a, and reference may be made to the description of the step S102a, where 100 is changed to 50, 99 is changed to 49, which is not repeated in the embodiment of the present application.

And S103b, charging the battery after 100 times of discharging through the current with the size of 2C, so that the voltage corresponding to the charged battery is a capacity-separable voltage.

The content related to the step S103b is the same as that related to the step S103a, and the description of the step S103a is referred to and will not be repeated here.

S104b, carrying out capacity division based on the charged battery, and determining that the capacity of the battery meets the requirement.

The content related to the step S104b is the same as that related to the step S104, and the description of the step S104 is referred to and will not be repeated here.

S105b, packaging the battery meeting the requirements and the like to obtain the target battery.

The content related to this step S105b is the same as that related to the foregoing step S105, and reference may be made to the foregoing description of step S105, which is not repeated here.

Fig. 7 shows a schematic diagram of the target cell obtained under the 3 rd set of parameters.

Wherein the 3 rd set of parameters comprises: in step S102, N is 150, and the process of discharging the formed battery 150 times is divided into 2 different stages. The 1 st stage includes 100 discharges, the overdischarge voltage in the 1 st stage is 2.2V, and each discharge in the 1 st stage is discharged with a current of 0.1C. The 2 nd stage includes 50 discharges, the overdischarge voltage in the 2 nd stage is 1.8V, and each discharge in the 2 nd stage is discharged with a current of 0.01C. In both phases, the discharge interval time was 5min. The current used when charging the battery in step S103 is 2C.

The process of obtaining the target battery based on the 2 nd group parameter may refer to the following description of step S101 c-step S105 c.

S101c, forming the battery to obtain a formed battery, wherein a protective film 1 is formed on the negative electrode of the formed battery.

The content related to this step S101c is the same as that related to the foregoing step S101, and reference may be made to the foregoing description of step S101, which is not repeated here.

S102c. discharging the battery to a voltage of 2.2V by a current of 0.1C to obtain a battery after one discharge, and then performing operation 1 in a cycle of 99 times, the operation 1 comprising: after 5 minutes, the cell after the last discharge was discharged again to a voltage of 2.2V by continuing to pass a current of 0.1C. Operation 2 is then performed 50 times in a loop, and operation 2 includes: after 5 minutes, the battery after the last discharge was discharged again to a voltage of 1.8V by a current of 0.01C, to obtain a battery after 150 discharges, in which the negative electrode produced a protective film 2, the protective film 2 being obtained based on the protective film 1.

This step S102c can be regarded as an exemplary scenario of discharging the battery using the deep discharge pattern 2.

In step S102c, 150 discharges are performed on the formed battery, and a battery after 150 discharges is obtained. The process of 150 discharges of the battery after formation is divided into 2 different stages. The discharge was performed 100 times in the 1 st stage, and then the discharge was performed in the 2 nd stage, and 50 times in the 2 nd stage. The discharging process in each of the two stages is similar to the step S102a, and reference is made to the description of the step S102a, which is not repeated here.

And S103C, charging the battery after 100 times of discharging through the current with the size of 2C, so that the voltage corresponding to the charged battery is a capacity-separable voltage.

The content related to the step S103c is the same as that related to the step S103a, and the description of the step S103a is referred to and will not be repeated here.

S104c, carrying out capacity division based on the charged battery, and determining that the capacity of the battery meets the requirement.

The content related to the step S104c is the same as that related to the step S104, and the description of the step S104 is referred to and will not be repeated here.

S105c, packaging the battery meeting the requirements and the like to obtain the target battery.

The content related to this step S105c is the same as that related to the foregoing step S105, and reference may be made to the foregoing description of step S105, which is not repeated here.

It should be understood that the 3 sets of parameters referred to above are merely exemplary descriptions and should not be construed as limiting embodiments of the application. In the actual processing process of the battery, the target battery can be obtained based on other parameters, and the specific setting of the parameters is not limited in the embodiment of the application, and the adjustment can be performed according to the capacity of the battery.

Fig. 8 shows a schematic diagram of a battery processing apparatus according to an embodiment of the present application.

As shown in fig. 8, the battery processing apparatus may include a formation device, a charge and discharge device, and a packaging device.

The formation device can be used for forming the battery to obtain the formed battery.

The charging and discharging device can be used for discharging the formed battery for N times, so that the voltage corresponding to the battery after each discharge is the overdischarge voltage, and the battery after N times of discharge is obtained.

The method can also be used for charging the battery after N times of discharging, so that the voltage corresponding to the charged battery is the capacity-variable voltage.

The method can also be used for carrying out capacity division on the charged battery to determine the battery meeting the requirements.

The packaging device can be used for packaging the battery meeting the requirements and the like to obtain the target battery.

An exemplary electronic device provided by an embodiment of the present application is first described below.

The embodiment will be specifically described below with reference to an electronic device as an example. It should be understood that the electronic device may have more or fewer components than shown in fig. 9, may combine two or more components, or may have a different configuration of components. The various components shown in fig. 9 may be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and/or application specific integrated circuits.

The electronic device may include: processor 110, external memory interface 120, internal memory 121, universal serial bus (universal serial bus, USB) interface 130, charge management module 140, power management module 141, battery 142, antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, audio module 170, speaker 170A, receiver 170B, microphone 170C, headset interface 170D, sensor module 180, keys 190, motor 191, indicator 192, camera 193, display 194, and subscriber identity module (subscriber identification module, SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyro sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, and the like.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

As used in the above embodiments, the term "when …" may be interpreted to mean "if …" or "after …" or "in response to determination …" or "in response to detection …" depending on the context. Similarly, the phrase "at the time of determination …" or "if detected (a stated condition or event)" may be interpreted to mean "if determined …" or "in response to determination …" or "at the time of detection (a stated condition or event)" or "in response to detection (a stated condition or event)" depending on the context.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk), etc.

Those of ordinary skill in the art will appreciate that implementing all or part of the above-described method embodiments may be accomplished by a computer program to instruct related hardware, the program may be stored in a computer readable storage medium, and the program may include the above-described method embodiments when executed. And the aforementioned storage medium includes: ROM or random access memory RAM, magnetic or optical disk, etc.

Claims

1. A battery processing method, the method comprising:

charging the battery injected with the electrolyte for the first time to perform formation to obtain a formed battery; the anode of the battery after formation is provided with a first protective film, and the first protective film is generated by the reduction reaction of the electrolyte on the anode in the formation process;

discharging the formed battery for N times, so that the voltage corresponding to the battery after each discharge is over-discharge voltage, and obtaining the battery after N times of discharge; the negative electrode in the battery after the N times of discharging is provided with a second protective film; the second protective film is obtained after the electrolyte and the negative electrode are in contact reaction to generate other components after part or all of the components in the first protective film are decomposed in the N discharging processes; the overdischarge voltage is smaller than the shutdown voltage of the battery in the using process; the N is an integer greater than or equal to 1;

Charging the battery after the N times of discharging with a first current, so that the voltage corresponding to the charged battery is a capacity-separable voltage; the capacity-separable voltage is larger than the overdischarge voltage and smaller than the full-charge voltage; and the full-charge voltage is the voltage corresponding to the condition that the charged battery is continuously fully charged.

2. The method of claim 1, wherein after charging the N discharged batteries with a first current such that the voltages corresponding to the charged batteries are the partitionable voltages, the method further comprises:

continuously charging the charged battery to be fully charged by a second current to obtain a fully charged battery; the second current is greater than the first current;

discharging the fully charged battery, and recording the total discharged electric quantity as the capacity of the battery;

and after the capacity of the battery meets the requirement, packaging the battery with the capacity meeting the requirement to obtain the target battery.

3. The method according to claim 1 or 2, characterized in that the formed battery is discharged N times, in particular comprising:

the process of discharging the formed battery for N times comprises T different stages, wherein the currents output by the different stages in the T stages are different when the battery is discharged, and the currents output by the battery in each stage in the T stages are the same.

4. The method according to claim 1 or 2, characterized in that the formed battery is discharged N times, in particular comprising:

and discharging the battery to an overdischarge voltage by using the same current in each of N times of discharging of the battery after formation.

5. The method according to any one of claims 1-4, characterized in that charging the battery after said N discharges with a first current, in particular comprises:

the process of charging the battery after the N times of discharging comprises D stages, wherein the first current used when the battery after the N times of discharging is charged in different stages in the D stages is different; the same phase of the D phases is the same as the first current used when the battery after the N times of discharging is charged; and D is an integer greater than or equal to 2.

6. The method according to any one of claims 1-4, characterized in that charging the battery after said N discharges with a first current, in particular comprises:

and charging the battery after the N times of discharging with the first current with the same magnitude.

7. The method according to claim 3, wherein the process of discharging the formed battery N times is divided into T different phases, the currents output when the battery is discharged in different phases of the T phases are different, and the currents output when the battery is discharged each time in the same phase of the T phases are the same, specifically including:

Dividing the process of discharging the battery subjected to the formation for N times into 2 different stages;

in a first stage, discharging the formed battery to a voltage of 2.2V by a current of 0.1C to obtain a discharged battery, and then performing a first operation cycle 99 times, the first operation comprising: after 5 minutes, the battery after the last discharge is discharged again to a voltage of 2.2V by continuing to pass through 0.1C current;

a second stage of performing a second operation loop 50 times, the second operation comprising: after 5 minutes, the battery after the last discharge was discharged again to a voltage of 1.8V by a current of 0.01C; then, a battery after 150 discharges was obtained; wherein C indicates a capacity value of the battery.

8. The method of claim 4, wherein each of the N discharges of the formed battery discharges the battery to an overdischarge voltage at the same current, comprising:

discharging the formed battery to a voltage of 2.2V by a current of 0.1C to obtain a battery after one discharge, and then performing a first operation cycle 99 times, the first operation comprising: after 5 minutes, the battery after the last discharge is discharged again to a voltage of 2.2V by continuing to pass through 0.1C current; then, a battery after 100 discharges was obtained; wherein C indicates a capacity value of the battery.

9. The method of claim 4, wherein each of the N discharges of the formed battery discharges the battery to an overdischarge voltage at the same current, comprising:

discharging the formed battery to a voltage of 2.2V by a current of 0.1C to obtain a discharged battery, and then performing a first operation cycle 49 times, the first operation comprising: after 5 minutes, the battery after the last discharge is discharged again to a voltage of 2.2V by continuing to pass through 0.1C current; then, a battery after 50 discharges was obtained; wherein C indicates a capacity value of the battery.

10. The method of any one of claims 6-8, wherein the battery is a full voltage equal to 4.0V-4.6V battery; the first current is 0.001C-5C.

11. A battery comprising electrolyte and a negative electrode, wherein the battery is formed by charging the battery injected with the electrolyte for the first time to obtain a formed battery; the anode in the battery after formation is provided with a first protective film; the battery after formation is subjected to N times of discharging, so that the voltage corresponding to the battery after each time of discharging is over-discharge voltage, and the battery after N times of discharging is obtained; after part or all of the components in the first protective film of the negative electrode in the battery after N times of discharging are decomposed, the electrolyte and the negative electrode are in contact reaction to generate other components, and then the second protective film is obtained.