Battery processing method and battery processing device

Abstract

The present application provides a battery treatment method, a battery treatment device, a battery, and an electrical device. The battery treatment method includes: obtaining a battery to be treated, wherein the anode surface of the battery has a solid electrolyte interface membrane formed thereon and the battery has a first preset voltage; controlling the battery to discharge from the first preset voltage to a second preset voltage, wherein the second preset voltage is at least lower than the decomposition voltage of the solid electrolyte interface membrane and higher than the decomposition voltage of water; and performing constant voltage charging on the battery at the second preset voltage.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery processing method and a battery processing device. Background Art

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0003] During the manufacturing and use of batteries, moisture often exists in the materials inside the battery. This moisture exists in various forms, such as free water, bound water, etc. The moisture in the battery will affect the battery performance and service life. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of this application is to provide a battery treatment method, a battery treatment device, and a battery to reduce moisture in the battery and alleviate the impact of moisture in the battery on battery performance and service life.

[0005] An embodiment of the first aspect of the present application provides a battery processing method, comprising:

[0006] Obtaining a battery to be processed, wherein a solid electrolyte interface film is formed on an anode surface of the battery, and the battery has a first preset voltage;

[0007] controlling the battery to discharge from the first preset voltage to a second preset voltage, wherein the second preset voltage is at least lower than a decomposition voltage of the solid electrolyte interface membrane and higher than a decomposition voltage of water; and

[0008] The battery is charged at a constant voltage at the second preset voltage.

[0009] In the technical solution of the embodiment of the present application, a battery having a first preset voltage after forming a solid electrolyte interface membrane is discharged to a second preset voltage, and the battery is constant-voltage charged at the second preset voltage. Since the battery has the first preset voltage before discharge, that is, the battery is charged to the first preset voltage before constant-voltage charging at the second preset voltage, the water in the pores of the battery's electrode material is fully released. Since the second preset voltage is greater than the decomposition voltage of the solid electrolyte interface membrane and higher than the decomposition voltage of water, when the battery is constant-voltage charged at the second preset voltage, the water released from the pores of the electrode material can be electrolyzed, and damage to the formed solid electrolyte interface membrane can be avoided. While avoiding damage to battery performance, the water in the pores of the electrode material can be reduced, thereby more thoroughly removing water from the battery, improving the dehydration effect, reducing the water in the battery, and alleviating the impact of the water in the battery on battery performance and service life.

[0010] In some embodiments, the first preset voltage is a preset multiple of the full charge voltage of the battery, and the preset multiple is in a range of 0.4 to 1. The battery to be processed has a first preset voltage that is a preset multiple of the full charge voltage, so that the battery to be processed is a battery that has been charged to the first preset voltage, wherein the electrode sheet is fully expanded, thereby fully releasing water in the pores of the electrode material, thereby improving the effect of subsequent removal of the released water in the pores of the electrode material.

[0011] In some embodiments, the second preset voltage ranges from 1.5 V to 2.0 V. By performing constant voltage charging to remove water at the second preset voltage within the range of 1.5 V to 2.0 V, the water removal efficiency is improved while avoiding affecting the electrode materials in the battery.

[0012] In some embodiments, the constant-voltage charging of the battery at the second preset voltage is performed at a preset temperature, and the preset temperature range is 25° C. to 60° C. By performing constant-voltage charging of the battery at the second preset voltage at a preset temperature within the range of 25° C. to 60° C., water removal efficiency is improved.

[0013] In some embodiments, performing constant voltage charging on the battery at the second preset voltage includes:

[0014] In response to the battery being electrically connected to a constant-voltage charging power supply having the second preset voltage, obtaining a time when the battery is electrically connected to the constant-voltage charging power supply; and

[0015] In response to the time when the battery is electrically connected to the constant-voltage charging power supply reaching a preset time, the battery is disconnected from the constant-voltage charging power supply, and the preset time ranges from 6 hours to 24 hours.

[0016] By removing water within a preset time of 6 hours to 24 hours, the water removal efficiency is improved while avoiding affecting battery production efficiency.

[0017] In some embodiments, performing constant voltage charging on the battery at the second preset voltage includes:

[0018] In response to the battery being electrically connected to a constant voltage charging power source having the second preset voltage, obtaining a volume of gas in the battery at a plurality of time points; and

[0019] In response to a difference between a gas volume obtained at a first time point and a gas volume obtained at a second time point among the multiple time points being not greater than a preset value, the battery is disconnected from the constant voltage charging power supply.

[0020] For the batteries to be processed, the gas volume inside the batteries is measured to determine the end time point of constant-voltage charging of the batteries at a second preset voltage. This allows different constant-voltage charging times to be used for dehydration of different batteries to be processed, so that each battery to be processed can reach the same state after dehydration, ultimately achieving balanced dehydration and further improving battery performance.

[0021] In some embodiments, obtaining the battery to be processed comprises:

[0022] Dehydrating the battery after packaging the positive electrode sheet, the negative electrode sheet and the separator;

[0023] performing a solid electrolyte interface film forming process on the battery after water removal; and

[0024] The battery having the solid electrolyte interface film formed thereon is charged to the first preset voltage.

[0025] Batteries that have been dehydrated before the formation process are used as batteries to be processed, so that the batteries are completely dehydrated before shipment, thereby improving the performance of the batteries when shipped.

[0026] In some embodiments, the step of removing water from the battery after packaging the positive electrode sheet, the negative electrode sheet, and the separator comprises:

[0027] The packaged battery is charged at a constant voltage at a third preset voltage, wherein the third preset voltage is at least higher than the hydrolysis voltage of water.

[0028] Before the formation process, the battery is dehydrated by electrolysis, so that the battery has high dehydration efficiency and good dehydration effect before formation.

[0029] In some embodiments, the third preset voltage is lower than the reaction voltage of the electrolyte in the packaged battery, so as to avoid decomposition of the electrolyte during the process of removing water from the battery by electrolysis before the formation process, thereby preventing the battery performance from being affected.

[0030] In some embodiments, the third preset voltage is lower than a voltage for forming the solid electrolyte interface film.

[0031] Avoid the formation of a solid electrolyte interface film during the process of dehydrating the battery by electrolysis before the formation process, which will affect the subsequent formation process and thus affect the battery performance.

[0032] In some embodiments, the third preset voltage ranges from 0.5V to 2V.

[0033] By removing water from the battery before performing the formation process at a third preset voltage of 0.5V to 2V, the water removal efficiency is improved.

[0034] In some embodiments, obtaining the battery to be processed comprises:

[0035] In response to obtaining a battery that has been charged and discharged a preset number of times, the battery that has been charged and discharged a preset number of times is determined as the battery to be processed.

[0036] Batteries that have been charged and discharged multiple times after shipment are used as batteries to be processed, so that the batteries can be further dehydrated during use after shipment, thereby improving the performance of the batteries during use and extending the life of the batteries during use.

[0037] According to another aspect of the present application, a battery processing device is provided, comprising:

[0038] a battery acquisition unit configured to obtain a battery to be processed, wherein a solid electrolyte interface film is formed on an anode surface of the battery, and the battery has a first preset voltage;

[0039] a discharge unit configured to control the battery to discharge from the first preset voltage to a second preset voltage, wherein the second preset voltage is at least lower than a decomposition voltage of the solid electrolyte interface membrane and higher than a decomposition voltage of water; and

[0040] The charging unit is configured to perform constant voltage charging on the battery at the second preset voltage.

[0041] In the technical solution of the embodiment of the present application, a battery having a first preset voltage after forming a solid electrolyte interface membrane is discharged to a second preset voltage, and the battery is constant-voltage charged at the second preset voltage. Since the battery has the first preset voltage before discharge, that is, the battery is charged to the first preset voltage before constant-voltage charging at the second preset voltage, the water in the pores of the battery's electrode material is fully released. Since the second preset voltage is greater than the decomposition voltage of the solid electrolyte interface membrane and higher than the decomposition voltage of water, when the battery is constant-voltage charged at the second preset voltage, the water released from the pores of the electrode material can be electrolyzed, and damage to the formed solid electrolyte interface membrane can be avoided. While avoiding damage to battery performance, the water in the pores of the electrode material can be reduced, thereby more thoroughly removing water from the battery, improving the dehydration effect, reducing the water in the battery, and alleviating the impact of the water in the battery on battery performance and service life.

[0042] In some embodiments, the first preset voltage is a preset multiple of the full charge voltage of the battery, and the preset multiple is in a range of 0.4 to 1. The battery to be processed has a first preset voltage that is a preset multiple of the full charge voltage, so that the battery to be processed is a battery that has been charged to the first preset voltage, wherein the electrode sheet is fully expanded, thereby fully releasing water in the pores of the electrode material, thereby improving the effect of subsequent removal of the released water in the pores of the electrode material.

[0043] In some embodiments, the second preset voltage ranges from 1.5 V to 2.0 V. By performing constant voltage charging to remove water at the second preset voltage within the range of 1.5 V to 2.0 V, the water removal efficiency is improved while avoiding affecting the electrode materials in the battery.

[0044] In some embodiments, the constant-voltage charging of the battery at the second preset voltage is performed at a preset temperature, and the preset temperature range is 25° C. to 60° C. By performing constant-voltage charging of the battery at the second preset voltage at a preset temperature within the range of 25° C. to 60° C., water removal efficiency is improved.

[0045] In some embodiments, the charging unit includes:

[0046] a time acquisition unit configured to obtain a time when the battery is electrically connected to the constant-voltage charging power supply having the second preset voltage in response to the battery being electrically connected to the constant-voltage charging power supply; and

[0047] The first control unit is configured to disconnect the battery from the constant-voltage charging power supply in response to the time when the battery is electrically connected to the constant-voltage charging power supply reaching a preset time, where the preset time ranges from 6 hours to 24 hours.

[0048] By removing water within a preset time of 6 hours to 24 hours, the water removal efficiency is improved while avoiding affecting battery production efficiency.

[0049] In some embodiments, the charging unit includes:

[0050] a gas volume detection unit configured to obtain the gas volume in the battery at a plurality of time points in response to the battery being electrically connected to a constant voltage charging power supply having the second preset voltage; and

[0051] The second control unit is configured to disconnect the battery from the constant voltage charging power supply in response to a difference between the gas volume obtained at a first time point and the gas volume obtained at a second time point among the multiple time points being not greater than a preset value.

[0052] For the batteries to be processed, the gas volume inside the batteries is measured to determine the end time point of constant-voltage charging of the batteries at a second preset voltage. This allows different constant-voltage charging times to be used for dehydration of different batteries to be processed, so that each battery to be processed can reach the same state after dehydration, ultimately achieving balanced dehydration and further improving battery performance.

[0053] In some embodiments, the battery acquisition unit includes:

[0054] a dehydration unit configured to dehydrate the battery after the positive electrode sheet, the negative electrode sheet and the separator are packaged;

[0055] a solid electrolyte interface film forming unit configured to perform a solid electrolyte interface film forming process on the battery after water removal;

[0056] The first charging subunit is configured to charge the battery having the solid electrolyte interface membrane formed thereon to the first preset voltage.

[0057] Batteries that have been dehydrated before the formation process are used as batteries to be processed, so that the batteries are completely dehydrated before shipment, thereby improving the performance of the batteries when shipped.

[0058] In some embodiments, the water removal unit comprises:

[0059] The second charging subunit is configured to perform constant voltage charging on the packaged battery at a third preset voltage, wherein the third preset voltage is at least higher than the hydrolysis voltage of water.

[0060] Before the formation process, the battery is dehydrated by electrolysis, so that the battery has high dehydration efficiency and good dehydration effect before formation.

[0061] In some embodiments, the third preset voltage is lower than the reaction voltage of the electrolyte in the packaged battery, so as to avoid decomposition of the electrolyte during the process of removing water from the battery by electrolysis before the formation process, thereby preventing the battery performance from being affected.

[0062] In some embodiments, the third preset voltage is lower than a voltage for forming the solid electrolyte interface film.

[0063] Avoid the formation of a solid electrolyte interface film during the process of dehydrating the battery by electrolysis before the formation process, which will affect the subsequent formation process and thus affect the battery performance.

[0064] In some embodiments, the third preset voltage ranges from 0.5 V to 2 V. By removing water from the battery before performing the formation process at the third preset voltage of 0.5 V to 2 V, the water removal efficiency is improved.

[0065] In some embodiments, the battery acquisition unit includes:

[0066] The determining unit is configured to, in response to obtaining a battery that has been charged and discharged a preset number of times, determine the battery that has been charged and discharged a preset number of times as the battery to be processed.

[0067] Batteries that have been charged and discharged multiple times after shipment are used as batteries to be processed, so that the batteries can be further dehydrated during use after shipment, thereby improving the performance of the batteries during use and extending the life of the batteries during use.

[0068] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0070] Figure 1 is a flow chart of a battery processing method according to some embodiments of the present application;

[0071] Figure 2 A flowchart of a process for obtaining a battery to be processed in a battery processing method according to some embodiments of the present application;

[0072] Figure 3is a schematic diagram of a process of charging and discharging a packaged battery according to some embodiments of the present application; and

[0073] Figure 4 is a schematic block diagram of a battery processing device according to some embodiments of the present application. DETAILED DESCRIPTION

[0074] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0076] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0077] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0078] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0079] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0080] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0081] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0082] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0083] The inventors have noted that electrode materials contain various forms of water, such as free water and bound water. These various forms of water have different adsorption energies and corresponding evaporation temperatures, making them difficult to remove all at once. For example, during battery manufacturing, electrode materials are often stirred into a slurry, coated onto a substrate, and cold-pressed to form electrode sheets. Because the particles are tightly packed together, some of the water trapped between the particles of the electrode material is difficult to remove.

[0084] During battery charging, the electrode sheets often expand. For example, during battery manufacturing, from the time the battery is dehydrated to the first charge and charged to full voltage, the thickness of the anode electrode sheet can increase by 15%, and the thickness of the cathode electrode sheet can increase by 4.8%. This expansion of the electrode sheet often releases water from the gaps between the electrode material particles, and this released water affects the battery life and performance.

[0085] According to one aspect of the present application, a battery processing method is provided. Figure 2 As shown, a battery processing method 100 according to an embodiment of the present application includes:

[0086] Step S110: obtaining a battery to be processed, wherein a solid electrolyte interface film is formed on an anode surface of the battery, and the battery has a first preset voltage;

[0087] Step S120: controlling the battery to discharge from the first preset voltage to a second preset voltage, where the second preset voltage is at least lower than the decomposition voltage of the solid electrolyte interface membrane and higher than the decomposition voltage of water; and

[0088] Step S130: performing constant voltage charging on the battery at the second preset voltage.

[0089] According to an embodiment of the present application, the battery to be processed can be an unused battery after the positive electrode sheet, negative electrode sheet and battery cell are packaged; or it can be a used battery that has been charged and discharged several times.

[0090] It is understood that an unused battery may be one that has not yet been shipped ("shipped" means shipped by the battery manufacturer after the battery manufacturing process has been completed). A used battery may be one that has been shipped and then charged or discharged several times by the user of the battery (the person who purchased the battery or the electrical device containing the battery).

[0091] In some embodiments, a solid electrolyte interface film is formed on the anode surface of the battery to be processed and has a first preset voltage, that is, the battery is a battery after a solid electrolyte interface film is formed through a formation process, and is charged to the first preset voltage.

[0092] As the battery undergoes the formation process and is charged to a first preset voltage, the electrode plates expand, increasing the gaps between the electrode material particles on the plates. This releases moisture from the gaps between the electrode material particles. This released moisture affects the battery's lifespan and performance.

[0093] In an embodiment of the present application, controlling the battery to discharge from the first preset voltage to the second preset voltage may include electrically connecting the battery to a power consumption device to discharge the battery. The power consumption device may be, for example, a resistor, an electrical device, etc., which is not limited herein.

[0094] In some embodiments, during the process of discharging the battery from a first preset voltage to a second preset voltage, the battery voltage can be monitored by a voltage measuring device, so that when the battery voltage reaches the second preset voltage, the battery is disconnected from the power consuming device. It is understood that the first preset voltage is greater than the second preset voltage.

[0095] In some embodiments, the battery is discharged at a preset temperature and pressure to a second preset voltage, for example, below 0° C., to avoid damaging electrode materials in the battery.

[0096] In some embodiments, a constant voltage charging device is used to perform constant voltage charging on the battery at a second preset voltage.

[0097] By discharging a battery having a first preset voltage after forming a solid electrolyte interface membrane to a second preset voltage, and then subjecting the battery to constant voltage charging at the second preset voltage, the battery has the first preset voltage before being discharged, i.e., the battery is charged to the first preset voltage before being subjected to constant voltage charging at the second preset voltage, so that water in the pores of the battery's electrode material is fully released. Since the second preset voltage is greater than the decomposition voltage of the solid electrolyte interface membrane and higher than the decomposition voltage of water, when the battery is subjected to constant voltage charging at the second preset voltage, the water released from the pores of the electrode material can be electrolyzed while avoiding damage to the formed solid electrolyte interface membrane. This can more thoroughly remove water from the battery by reducing the water in the pores of the electrode material while avoiding damage to battery performance, thereby improving the dehydration effect, reducing the water content in the battery, and alleviating the impact of water content in the battery on battery performance and service life.

[0098] In some embodiments, as Figure 2 As shown, obtaining the battery to be processed includes:

[0099] Step S210: dehydrating the battery after packaging the positive electrode sheet, the negative electrode sheet and the separator;

[0100] Step S220: performing a solid electrolyte interface film forming process on the battery after water removal; and

[0101] Step S230: charging the battery having the solid electrolyte interface membrane formed thereon to the first preset voltage.

[0102] In some embodiments, the process of preparing a battery includes: preparing a positive electrode sheet; preparing a negative electrode sheet, preparing an electrolyte, and packaging the positive electrode sheet, the negative electrode sheet, and a separator.

[0103] In some embodiments, the process of preparing a positive electrode sheet includes: mixing a positive electrode active material, a conductive agent, and a binder, adding a solvent and stirring to form a positive electrode slurry; coating the positive electrode slurry on a positive electrode collector, and drying and cold pressing to obtain a positive electrode sheet.

[0104] In some embodiments, the positive electrode active material may be lithium nickel cobalt manganese oxide, the conductive agent may be acetylene black, the binder may be polyvinylidene fluoride, the solvent may be N-methylpyrrolidone, etc., which are not limited here.

[0105] In some embodiments, the process of preparing a negative electrode sheet includes: mixing a negative electrode active material, a conductive agent, and a binder, adding deionized water and stirring to form a negative electrode slurry; coating the negative electrode slurry on a negative electrode collector, and drying and cold pressing to obtain a negative electrode sheet.

[0106] In some embodiments, the negative electrode active material may be graphite, the conductive agent may be acetylene black, the binder may be styrene-butadiene rubber, etc., which are not limited here.

[0107] In some embodiments, the electrolyte may include lithium salts, additives, etc., which are not limited here.

[0108] In some embodiments, the process of packaging the positive electrode sheet, the negative electrode sheet and the separator into a battery includes: stacking the positive electrode sheet, the separator and the negative electrode sheet in sequence, and then winding them to obtain a battery cell; after placing the battery cell in an outer packaging foil, injecting the electrolyte into the dried battery, and then vacuum packaging and standing to obtain a packaged battery.

[0109] It can be understood that the above process of preparing the positive electrode sheet and the negative electrode sheet causes moisture in various forms to exist in the packaged battery.

[0110] In some embodiments, a drying method is used in a vacuum environment to remove water from the battery after the positive electrode sheet, the negative electrode sheet and the separator are packaged.

[0111] In some embodiments, the battery after packaging is charged at a constant voltage to electrolyze the water in the battery after packaging, thereby removing water from the battery after packaging the positive electrode sheet, the negative electrode sheet and the separator.

[0112] In some embodiments of the present application, during the battery preparation process, after the battery is dehydrated, a solid electrolyte interface film formation process (i.e., a formation process) is further performed. In some embodiments, the battery is charged with a constant current to activate the positive electrode active material and the negative electrode active material in the battery, and form a solid electrolyte interface film.

[0113] During the solid electrolyte interface film formation process, the materials in the positive electrode sheet and the negative electrode sheet expand slightly, so that a small amount of water in the gaps between the electrode sheet materials is released.

[0114] In some cases, batteries with a solid electrolyte interface membrane (SEI) are charged to full charge voltage to complete the battery manufacturing process. The fully charged batteries undergo subsequent quality inspection before shipment. When batteries with a solid electrolyte interface membrane (SEI) are charged to full charge voltage, the materials in the positive and negative electrode sheets expand sufficiently, completely releasing any moisture trapped in the gaps between the sheet materials. Consequently, the battery's performance during shipment may not be optimal due to the residual moisture.

[0115] Batteries that have been dehydrated before the formation process are used as batteries to be processed, so that the batteries are completely dehydrated before shipment, thereby improving the performance of the batteries when shipped.

[0116] In some embodiments, the step of removing water from the battery after packaging the positive electrode sheet, the negative electrode sheet, and the battery cell comprises:

[0117] The packaged battery is charged at a constant voltage at a third preset voltage, wherein the third preset voltage is at least higher than the hydrolysis voltage of water.

[0118] The battery after packaging and before the formation process is subjected to constant voltage charging at a third preset voltage. Since the third preset voltage is higher than the hydrolysis voltage of water, water in the battery can be hydrolyzed during the constant voltage charging of the battery at the third preset voltage. In some embodiments, the free water in the battery is electrolyzed by the reactions shown in the following formulas (1) and (2):

[0119] 2H2O+2e - →H2+2OH - (Formula 1)

[0120] 2H2O+LiPF6+4e - →LiPO2F2+2H2+4F - (Formula 2)

[0121] In some embodiments, the third preset voltage is 1.0V.

[0122] See Figure 3 , shows a schematic diagram of the process of charging and discharging the packaged battery in the battery processing method according to an embodiment of the present application. Figure 3 As shown, the horizontal axis represents the various stages in the battery processing method, and the vertical axis represents the voltage when the battery is charged and discharged.

[0123] In the dehydration stage 1, the packaged battery is dehydrated. In this stage, the packaged battery is charged at a constant voltage of V0 to hydrolyze the free water in the packaged battery. Because the electrode sheet material is compacted, the water (e.g., bound water) in the gaps between the electrode sheet materials cannot be removed.

[0124] During the formation phase, the battery undergoes a formation process to form a solid electrolyte interface layer after the dehydration phase 1. During this phase, a constant charging current is applied to the battery, increasing the battery voltage to V2. During this phase, the electrode sheet expands slightly, releasing a small amount of water from the gaps between the electrode sheet materials.

[0125] In the charging stage, the formed battery is charged to V3. During this stage, the electrode material is fully expanded, so that the moisture in the gap of the electrode material is fully released.

[0126] During the discharge phase, the battery is discharged from V3 to V1.

[0127] In the dehydration 2 stage, the discharged battery is dehydrated. In this stage, the battery is charged at a constant voltage at a voltage V1 so that the released water in the gaps between the electrode materials is hydrolyzed.

[0128] Before forming the solid electrolyte interface film, the battery is dehydrated by electrolysis, so that the battery has high dehydration efficiency and good dehydration effect before formation.

[0129] In some embodiments, the third preset voltage is lower than the reaction voltage of the electrolyte in the packaged battery.

[0130] The electrolyte contains a large amount of additives. The third preset voltage is set to be lower than the reaction voltage of the electrolyte in the packaged battery, so that the substances in the electrolyte do not undergo decomposition reaction during the electrolysis of water in the battery.

[0131] It can be understood that the voltage that can cause the substances in the electrolyte to undergo decomposition reactions is related to the components of the electrolyte.

[0132] In some embodiments, the third preset voltage is set to be lower than 2.5V so as to be lower than the reaction voltage of the electrolyte in the packaged battery.

[0133] Avoid decomposing the electrolyte during the process of removing water from the battery by electrolysis before the formation process, which may affect the battery performance.

[0134] In some embodiments, the third preset voltage is lower than a voltage for forming the solid electrolyte interface film.

[0135] The solid electrolyte interface (SEI) film is usually formed at the solid-liquid interface between the electrode material and the electrolyte. When the formation process begins, the lithium ions in the positive electrode active material enter the electrolyte, penetrate the diaphragm, and then enter the electrolyte, and are embedded in the layered voids of the negative electrode active material, allowing the lithium ions to complete the deintercalation behavior. At this time, electrons exit the positive electrode along the outer end loop and enter the negative electrode carbon material. Redox reactions occur between the electrons, the solvent in the electrolyte, and the lithium ions. After receiving the electrons, the solvent molecules combine with the lithium ions to form SEI and generate gases such as H2, CO, and CH2. As the SEI thickness increases until the electrons can no longer penetrate, a passivation layer is formed, which inhibits the continuation of the redox reaction. The thickness of the SEI film will affect the performance of the battery.

[0136] In an embodiment of the present application, the third preset voltage is set to be lower than the voltage for forming the SEI film, so that the SEI film is not formed during the electrolysis of water in the battery.

[0137] It can be understood that the voltage that enables the formation of the SEI film is related to the components of the positive electrode active material, the negative electrode active material, and the electrolyte.

[0138] In some embodiments, the third preset voltage is set to be lower than 2.0 V to be lower than a voltage at which a SEI film is formed.

[0139] Avoid the formation of a solid electrolyte interface film during the process of dehydrating the battery by electrolysis before the formation process, which will affect the subsequent formation process and thus affect the battery performance.

[0140] The third preset voltage ranges from 0.5V to 2V.

[0141] By removing water from the battery before performing the formation process at a third preset voltage of 0.5V to 2V, the water removal efficiency is improved.

[0142] In some embodiments, obtaining the battery to be processed comprises:

[0143] In response to obtaining a battery that has been charged and discharged a preset number of times, the battery that has been charged and discharged a preset number of times is determined as the battery to be processed.

[0144] During the battery's post-shipment use, as ions are embedded or extracted from the positive and negative active materials during the battery's charge and discharge cycles, the accumulation of side reaction products in the cell system and the exfoliation of graphite flakes cause the positive and negative electrode sheets to further expand. This further expansion releases moisture from the electrode materials, and the occurrence of side reactions also increases the amount of moisture in the battery, affecting its lifespan and performance.

[0145] In the embodiment of the present application, the battery has been charged and discharged for a preset number of times, that is, the battery has been used for a long time after shipment. Since the positive electrode active material and the negative electrode active material of the battery undergo several processes of embedding or de-ionizing ions during use, the water content therein increases compared to before shipment, affecting the performance and service life of the battery.

[0146] Batteries that have been charged and discharged multiple times after shipment are used as batteries to be processed, so that the batteries can be further dehydrated during use after shipment, thereby improving the performance of the batteries during use and extending the life of the batteries during use.

[0147] According to some embodiments of the present application, the first preset voltage is a preset multiple of the full charge voltage of the battery, and the preset multiple is in the range of 0.4 to 1. This allows the battery to be charged to the first preset voltage and dehydrated after the battery undergoes a formation process (forming a solid electrolyte interface film), thereby further dehydrating the battery after formation.

[0148] In some embodiments, the full charge voltage is determined by the battery's electrode material, and different battery materials have different full charge voltages. In one example, the battery's electrode material is a lithium-containing compound, and its full charge voltage is 4.2V.

[0149] In some embodiments, during the battery preparation process, the battery having a solid electrolyte interface membrane formed thereon through a formation process is charged to a first preset voltage to obtain a battery to be processed, wherein the first preset voltage is any value between the formation process voltage and the full charge voltage.

[0150] In one example, the preset multiple is 0.9.

[0151] The battery to be processed has a first preset voltage that is a preset multiple of the full charge voltage, so that the battery to be processed is a battery that has been charged to the first preset voltage, and the electrode sheets therein are fully expanded, so that the water in the pores of the electrode material is fully released, so that the subsequent removal of the water released in the pores of the electrode material is more effective.

[0152] In some embodiments, during battery use, batteries that have undergone multiple charge and discharge cycles are treated as batteries to be processed, wherein the first preset voltage can be any value between the charge cutoff voltage (i.e., the full charge voltage) and the discharge cutoff voltage. In one example, the discharge cutoff voltage is set based on the charge cutoff voltage and is a preset multiple of the charge cutoff voltage.

[0153] In some embodiments, the second preset voltage ranges from 1.5V to 2.0V.

[0154] The second preset voltage is a voltage used to hydrolyze water in the battery after constant voltage charging of the battery.

[0155] By performing constant voltage charging to remove water at a second preset voltage within a range of 1.5V to 2.0V, the water removal efficiency is improved while avoiding affecting the electrode materials in the battery.

[0156] In one example, the second preset voltage is 1.7V.

[0157] In some embodiments, the constant voltage charging of the battery at the second preset voltage is performed at a preset temperature, and the preset temperature ranges from 25° C. to 60° C.

[0158] In some embodiments, constant voltage charging of the battery is performed at the second preset voltage by placing the battery in an environment with a preset temperature.

[0159] In one example, an environment with a preset temperature is provided by a thermostat.

[0160] The inventors have found that by performing constant voltage charging on the battery at a second preset voltage in a constant temperature environment, the efficiency of water electrolysis is high and the electrolysis is sufficient, thereby improving the efficiency of water electrolysis. In one example, the constant voltage charging of the battery at the second preset voltage is performed at a preset temperature of 45°C.

[0161] By performing constant voltage charging on the battery at a second preset voltage at a preset temperature within a range of 25° C. to 60° C., the water removal efficiency is improved.

[0162] In some embodiments, constant voltage charging of the battery at the second preset voltage may also be performed in an environment where the temperature varies between 25° C. and 60° C. For example, constant voltage charging of the battery at the second preset voltage may be performed in multiple stages, wherein the first stage is constant voltage charging of the battery at the second preset voltage at 30° C.; the second stage is constant voltage charging of the battery at the second preset voltage at 40° C.; the third stage is constant voltage charging of the battery at the second preset voltage at 50° C., and so on.

[0163] In some embodiments, performing constant voltage charging on the battery at the second preset voltage includes:

[0164] In response to the battery being electrically connected to a constant-voltage charging power supply having the second preset voltage, obtaining a time when the battery is electrically connected to the constant-voltage charging power supply; and

[0165] In response to the time when the battery is electrically connected to the constant-voltage charging power supply reaching a preset time, the battery is disconnected from the constant-voltage charging power supply, and the preset time ranges from 6 hours to 24 hours.

[0166] In some embodiments, a first charging device is used to implement constant-voltage charging of a battery at a second preset voltage, wherein the first charging device includes a constant-voltage charging power supply of the second preset voltage and a timing unit, and a first control unit communicatively connected to the constant-voltage charging power supply and the timing device, respectively. When the constant-voltage charging power supply is electrically connected to the battery, a signal is sent to the first control unit to cause the first control unit to control the timing unit to start timing, wherein the time point at which the timing unit starts timing is a first time point. Simultaneously, in response to the time from the first time point reaching a preset time, the timing unit sends a signal to the first control unit to cause the first control unit to control the constant-voltage charging power supply to disconnect from the battery, thereby terminating constant-voltage charging of the battery at the second preset voltage.

[0167] In some embodiments, the first control unit may be a printed circuit board formed with a control circuit, or may be a control device including a memory storing program instructions and a processor.

[0168] The inventors found that by performing constant voltage charging on the battery at a second preset voltage for 6 to 24 hours, the efficiency of water electrolysis can be high and the electrolysis can be sufficient, thereby improving the water removal efficiency. At the same time, if the preset time range is exceeded, the water removal efficiency will no longer increase, and production efficiency may be affected.

[0169] In one example, constant voltage charging of the battery is performed at the second preset voltage for 12 hours.

[0170] By removing water within a preset time of 6 hours to 24 hours, the water removal efficiency is improved while avoiding affecting battery production efficiency.

[0171] It should be understood that the above embodiment is described by taking the example of performing constant-voltage charging of the battery at the second preset voltage for 6 hours to 24 hours. This is merely exemplary. Those skilled in the art should understand that the constant-voltage charging of the battery at the second preset voltage can be performed for any time, and the water released in the pores of the electrode material can be electrolyzed and removed, thereby achieving the technical effect of the present application.

[0172] In some embodiments, performing constant voltage charging on the battery at the second preset voltage includes:

[0173] In response to the battery being electrically connected to a constant voltage charging power source having the second preset voltage, obtaining a volume of gas in the battery at a plurality of time points; and

[0174] In response to a difference between a gas volume obtained at a first time point and a gas volume obtained at a second time point among the multiple time points being not greater than a preset value, the battery is disconnected from the constant voltage charging power supply.

[0175] In some embodiments, a second charging device is used to implement constant-voltage charging of the battery at a second preset voltage, wherein the second charging device includes a constant-voltage charging power supply and a gas detection unit of the second preset voltage, and a second control unit communicatively connected to the constant-voltage charging power supply and the gas detection unit. When the constant-voltage charging power supply is electrically connected to the battery, a signal is sent to the second control unit so that the second control unit controls the gas detection unit to begin detecting the gas inside the battery. Simultaneously, the gas detection unit sends the value of the detected gas volume inside the battery to the second control unit. In response to the difference between the two consecutively received gas volume values ​​being no greater than a preset value, the second control unit determines that the gas inside the battery is no longer changing, and therefore controls the constant-voltage charging power supply to be disconnected from the battery, thereby ending constant-voltage charging of the battery at the second preset voltage.

[0176] In some embodiments, the second control unit may be a printed circuit board formed with a control circuit, or may be a control device including a memory storing program instructions and a processor.

[0177] In some embodiments, for different batteries to be processed, the expansion degree of the electrode material is different, resulting in different amounts of water released from the pores of the electrode material.

[0178] For the batteries to be processed, the gas volume inside the batteries is measured to determine the end time point of constant-voltage charging of the batteries at a second preset voltage. This allows different constant-voltage charging times to be used for dehydration of different batteries to be processed, so that each battery to be processed can reach the same state after dehydration, ultimately achieving balanced dehydration and further improving battery performance.

[0179] According to another aspect of the present application, a battery processing device is also provided. Figure 4 As shown, the battery processing device 400 includes:

[0180] The battery acquisition unit 410 is configured to obtain a battery to be processed, wherein a solid electrolyte interface film is formed on an anode surface of the battery, and the battery has a first preset voltage;

[0181] a discharge unit 420 configured to control the battery to discharge from the first preset voltage to a second preset voltage, wherein the second preset voltage is at least lower than the decomposition voltage of the solid electrolyte interface membrane and higher than the decomposition voltage of water; and

[0182] The charging unit 430 is configured to perform constant voltage charging on the battery at the second preset voltage.

[0183] In some embodiments, the battery processing device according to the present application is implemented by a device comprising a memory storing program instructions and a processor, wherein each unit is implemented by each program module.

[0184] In some embodiments, the battery acquisition unit 410 determines the electrically connected battery as a battery to be processed in response to being electrically connected to the battery.

[0185] In some embodiments, the discharge unit 420 further includes a power consumption device, which is electrically connected to the battery to be processed to discharge the battery. The power consumption device is, for example, a resistor, an electrical device, etc., which is not limited here.

[0186] In some embodiments, the charging unit 430 includes a charging power source that can provide various voltages for constant voltage charging.

[0187] By discharging a battery having a first preset voltage after forming a solid electrolyte interface membrane to a second preset voltage, and then subjecting the battery to constant voltage charging at the second preset voltage, the battery has the first preset voltage before being discharged, i.e., the battery is charged to the first preset voltage before being subjected to constant voltage charging at the second preset voltage, so that water in the pores of the battery's electrode material is fully released. Since the second preset voltage is greater than the decomposition voltage of the solid electrolyte interface membrane and higher than the decomposition voltage of water, when the battery is subjected to constant voltage charging at the second preset voltage, the water released from the pores of the electrode material can be electrolyzed while avoiding damage to the formed solid electrolyte interface membrane. This can more thoroughly remove water from the battery by reducing the water in the pores of the electrode material while avoiding damage to battery performance, thereby improving the dehydration effect, reducing the water content in the battery, and alleviating the impact of water content in the battery on battery performance and service life.

[0188] In some embodiments, the first preset voltage is a preset multiple of the full charge voltage of the battery, and the preset multiple ranges from 0.4 to 1.

[0189] The battery to be processed has a first preset voltage that is a preset multiple of the full charge voltage, so that the battery to be processed is a battery that has been charged to the first preset voltage, and the electrode sheets therein are fully expanded, so that the water in the pores of the electrode material is fully released, so that the subsequent removal of the water released in the pores of the electrode material is more effective.

[0190] In some embodiments, the second preset voltage ranges from 1.5V to 2.0V.

[0191] By performing constant voltage charging to remove water at a second preset voltage within a range of 1.5V to 2.0V, the water removal efficiency is improved while avoiding affecting the electrode materials in the battery.

[0192] In some embodiments, the constant voltage charging of the battery at the second preset voltage is performed at a preset temperature, and the preset temperature ranges from 25° C. to 60° C.

[0193] By performing constant voltage charging on the battery at a second preset voltage at a preset temperature within a range of 25° C. to 60° C., the water removal efficiency is improved.

[0194] In some embodiments, the charging unit includes:

[0195] a time acquisition unit configured to obtain a time when the battery is electrically connected to the constant-voltage charging power supply having the second preset voltage in response to the battery being electrically connected to the constant-voltage charging power supply; and

[0196] The first control unit is configured to disconnect the battery from the constant-voltage charging power supply in response to the time when the battery is electrically connected to the constant-voltage charging power supply reaching a preset time, where the preset time ranges from 6 hours to 24 hours.

[0197] In some embodiments, the charging unit includes a constant-voltage charging power supply with a second preset voltage, a timing unit, and a first control unit communicatively connected to the constant-voltage charging power supply and the timing unit, respectively. When the constant-voltage charging power supply is electrically connected to the battery, the first control unit is sent a signal to control the timing unit to start timing, wherein the time point at which the timing unit starts timing is a first time point. Simultaneously, in response to the time from the first time point reaching a preset time, the timing unit is sent a signal to the first control unit to control the constant-voltage charging power supply to disconnect from the battery, thereby terminating constant-voltage charging of the battery at the second preset voltage.

[0198] In some embodiments, the first control unit may be a printed circuit board formed with a control circuit, or may be a control device including a memory storing program instructions and a processor.

[0199] In some embodiments, by removing water within a preset time of 6 hours to 24 hours, the water removal efficiency is improved while avoiding affecting the battery production efficiency.

[0200] In some embodiments, the charging unit includes:

[0201] a gas volume detection unit configured to obtain the gas volume in the battery at a plurality of time points in response to the battery being electrically connected to a constant voltage charging power supply having the second preset voltage; and

[0202] The second control unit is configured to disconnect the battery from the constant voltage charging power supply in response to a difference between the gas volume obtained at a first time point and the gas volume obtained at a second time point among the multiple time points being not greater than a preset value.

[0203] In some embodiments, the charging unit includes a constant-voltage charging power supply with a second preset voltage and a gas detection unit, and a second control unit communicatively connected to the constant-voltage charging power supply and the gas detection unit, respectively. When the constant-voltage charging power supply is electrically connected to the battery, it sends a signal to the second control unit so that the second control unit controls the gas detection unit to start detecting the gas inside the battery. Simultaneously, the gas detection unit sends the value of the detected gas volume inside the battery to the second control unit. In response to the difference between the two consecutively received gas volume values ​​being no greater than a preset value, the second control unit determines that the gas inside the battery is no longer changing, and therefore controls the constant-voltage charging power supply to be disconnected from the battery, thereby ending constant-voltage charging of the battery at the second preset voltage.

[0204] In some embodiments, the second control unit may be a printed circuit board formed with a control circuit, or may be a control device including a memory storing program instructions and a processor.

[0205] For the batteries to be processed, the gas volume inside the batteries is measured to determine the end time point of constant-voltage charging of the batteries at a second preset voltage. This allows different constant-voltage charging times to be used for dehydration of different batteries to be processed, so that each battery to be processed can reach the same state after dehydration, ultimately achieving balanced dehydration and further improving battery performance.

[0206] In some embodiments, the battery acquisition unit 410 includes:

[0207] a dehydration unit configured to dehydrate the battery after the positive electrode sheet, the negative electrode sheet and the separator are packaged;

[0208] a solid electrolyte interface film forming unit configured to perform a solid electrolyte interface film forming process on the battery after water removal;

[0209] The first charging subunit is configured to charge the battery having the solid electrolyte interface membrane formed thereon to the first preset voltage.

[0210] In some embodiments, the water removal unit is configured with a water removal charging subunit for applying a voltage at least higher than the electrolysis voltage of water to the battery to remove water by electrolysis.

[0211] In some embodiments, the solid electrolyte interface film forming unit includes a current charging subunit for applying a charging current to the battery to form the solid electrolyte interface film.

[0212] Batteries that have been dehydrated before the formation process are used as batteries to be processed, so that the batteries are completely dehydrated before shipment, thereby improving the performance of the batteries when shipped.

[0213] In some embodiments, the water removal unit comprises:

[0214] The second charging subunit is configured to perform constant voltage charging on the packaged battery at a third preset voltage, wherein the third preset voltage is at least higher than the hydrolysis voltage of water.

[0215] Before the formation process, the battery is dehydrated by electrolysis, so that the battery has high dehydration efficiency and good dehydration effect before formation.

[0216] In some embodiments, the third preset voltage is lower than the reaction voltage of the electrolyte in the packaged battery.

[0217] Avoid decomposing the electrolyte during the process of removing water from the battery by electrolysis before the formation process, which may affect the battery performance.

[0218] In some embodiments, the third preset voltage is lower than a voltage for forming the solid electrolyte interface film.

[0219] Avoid the formation of a solid electrolyte interface film during the process of dehydrating the battery by electrolysis before the formation process, which will affect the subsequent formation process and thus affect the battery performance.

[0220] In some embodiments, the third preset voltage ranges from 0.5V to 2V.

[0221] By removing water from the battery before performing the formation process at a third preset voltage of 0.5V to 2V, the water removal efficiency is improved.

[0222] In some embodiments, the battery acquisition unit includes:

[0223] The determining unit is configured to, in response to obtaining a battery that has been charged and discharged a preset number of times, determine the battery that has been charged and discharged a preset number of times as the battery to be processed.

[0224] Batteries that have been charged and discharged multiple times after shipment are used as batteries to be processed, so that the batteries can be further dehydrated during use after shipment, thereby improving the performance of the batteries during use and extending the life of the batteries during use.

[0225] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery processing method, comprising: Obtaining a battery to be processed, wherein a solid electrolyte interface film is formed on an anode surface of the battery, and the battery has a first preset voltage; Controlling the battery to discharge from the first preset voltage to a second preset voltage, where the second preset voltage is at least lower than a decomposition voltage of the solid electrolyte interface membrane and higher than a decomposition voltage of water; as well as The battery is charged at a constant voltage at the second preset voltage.

2. The method according to claim 1, wherein The first preset voltage is a preset multiple of the full charge voltage of the battery, and a value range of the preset multiple is 0.4 to 1.

3. The method according to claim 1 or 2, wherein: The second preset voltage ranges from 1.5V to 2.0V.

4. The method according to any one of claims 1 to 3, wherein The constant voltage charging of the battery at the second preset voltage is performed at a preset temperature, and the preset temperature range is 25° C. to 60° C.

5. The method according to any one of claims 1 to 4, wherein The constant voltage charging of the battery at the second preset voltage includes: In response to the battery being electrically connected to a constant-voltage charging power supply having the second preset voltage, obtaining a time when the battery is electrically connected to the constant-voltage charging power supply; and In response to the time when the battery is electrically connected to the constant-voltage charging power supply reaching a preset time, the battery is disconnected from the constant-voltage charging power supply, and the preset time ranges from 6 hours to 24 hours.

6. The method according to any one of claims 1 to 4, wherein The constant voltage charging of the battery at the second preset voltage includes: In response to the battery being electrically connected to a constant voltage charging power source having the second preset voltage, obtaining a volume of gas in the battery at a plurality of time points; and In response to a difference between a gas volume obtained at a first time point and a gas volume obtained at a second time point among the multiple time points being not greater than a preset value, the battery is disconnected from the constant voltage charging power supply.

7. The method according to any one of claims 1 to 6, wherein obtaining the battery to be processed comprises: Dehydrating the battery after packaging the positive electrode sheet, the negative electrode sheet and the separator; performing a solid electrolyte interface film forming process on the battery after water removal; as well as The battery having the solid electrolyte interface film formed thereon is charged to the first preset voltage.

8. The method according to claim 7, wherein: The dehydration of the battery after packaging the positive electrode sheet, the negative electrode sheet and the separator comprises: The packaged battery is charged at a constant voltage at a third preset voltage, wherein the third preset voltage is at least higher than the hydrolysis voltage of water.

9. The method according to claim 8, wherein The third preset voltage is also lower than the reaction voltage of the electrolyte in the packaged battery.

10. The method according to claim 8 or 9, wherein: The third preset voltage is also lower than the voltage for forming the solid electrolyte interface film.

11. The method according to any one of claims 8 to 10, wherein: The third preset voltage ranges from 0.5V to 2V.

12. The method according to any one of claims 1 to 6, wherein obtaining the battery to be processed comprises: In response to obtaining a battery that has been charged and discharged a preset number of times, the battery that has been charged and discharged a preset number of times is determined as the battery to be processed.

13. A battery processing device comprising: a battery acquisition unit configured to obtain a battery to be processed, wherein a solid electrolyte interface film is formed on an anode surface of the battery, and the battery has a first preset voltage; a discharge unit configured to control the battery to discharge from the first preset voltage to a second preset voltage, wherein the second preset voltage is at least lower than a decomposition voltage of the solid electrolyte interface membrane and higher than a decomposition voltage of water; as well as The charging unit is configured to perform constant voltage charging on the battery at the second preset voltage.

14. The device according to claim 13, wherein The first preset voltage is a preset multiple of the full charge voltage of the battery, and a value range of the preset multiple is 0.4 to 1.

15. The device according to claim 13 or 14, wherein The second preset voltage ranges from 1.5V to 2.0V.

16. The device according to any one of claims 13 to 15, wherein: The constant voltage charging of the battery at the second preset voltage is performed at a preset temperature, and the preset temperature range is 25° C. to 60° C.

17. The device according to any one of claims 13 to 16, wherein: The charging unit includes: a time acquisition unit configured to obtain a time when the battery is electrically connected to the constant-voltage charging power supply having the second preset voltage in response to the battery being electrically connected to the constant-voltage charging power supply; and The first control unit is configured to disconnect the battery from the constant-voltage charging power supply in response to the time when the battery is electrically connected to the constant-voltage charging power supply reaching a preset time, where the preset time ranges from 6 hours to 24 hours.

18. The device according to any one of claims 13 to 16, wherein: The charging unit includes: a gas volume detection unit configured to obtain the gas volume in the battery at a plurality of time points in response to the battery being electrically connected to a constant voltage charging power supply having the second preset voltage; and The second control unit is configured to disconnect the battery from the constant voltage charging power supply in response to a difference between the gas volume obtained at a first time point and the gas volume obtained at a second time point among the multiple time points being not greater than a preset value.

19. The device according to any one of claims 13 to 18, wherein: The battery acquisition unit includes: a dehydration unit configured to dehydrate the battery after the positive electrode sheet, the negative electrode sheet and the separator are packaged; a solid electrolyte interface film forming unit configured to perform a solid electrolyte interface film forming process on the battery after water removal; The first charging subunit is configured to charge the battery having the solid electrolyte interface membrane formed thereon to the first preset voltage.

20. The device according to claim 19, wherein The water removal unit comprises: The second charging subunit is configured to perform constant voltage charging on the packaged battery at a third preset voltage, wherein the third preset voltage is at least higher than the hydrolysis voltage of water.

21. The device according to claim 20, wherein The third preset voltage is also lower than the reaction voltage of the electrolyte in the packaged battery.

22. The device according to claim 20 or 21, wherein The third preset voltage is also lower than the voltage for forming the solid electrolyte interface film.

23. The device according to any one of claims 20 to 22, wherein: The third preset voltage ranges from 0.5V to 2V.

24. The device according to any one of claims 13 to 18, wherein The battery acquisition unit includes: The determining unit is configured to, in response to obtaining a battery that has been charged and discharged a preset number of times, determine the battery that has been charged and discharged a preset number of times as the battery to be processed.

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