CN116773607B

CN116773607B - Method and equipment for detecting lithium supplementing quantity

Info

Publication number: CN116773607B
Application number: CN202311073497.5A
Authority: CN
Inventors: 谢斌; 陈仕通
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-08-24
Filing date: 2023-08-24
Publication date: 2024-04-12
Anticipated expiration: 2043-08-24
Also published as: CN116773607A

Abstract

The embodiment of the application discloses a method and equipment for detecting lithium supplementing amount, wherein the method comprises the following steps: placing the film with the metal lithium into a container filled with a reaction solution, and obtaining a sample solution after a preset time period; the metal lithium comes from the pole piece; detecting the conductivity of a sample solution, and determining the conductivity of a reaction solution; and determining the lithium supplementing quantity of the unit area of the pole piece according to the conductivity of the reaction liquid. The accuracy of the lithium supplementing quantity can be improved through the lithium supplementing method.

Description

Method and equipment for detecting lithium supplementing quantity

Technical Field

The application relates to the technical field of batteries, in particular to a method and equipment for detecting lithium supplementing quantity.

Background

The lithium ion battery is widely applied to the fields of electronic products, electric automobile power batteries, energy storage and the like due to the advantages of high energy density, long service life, green pollution-free performance, safety performance and the like. The lithium element is supplemented on the surface of a high-capacity low-first-efficiency negative electrode piece (such as a silicon negative electrode, a silicon-carbon negative electrode, a tin-carbon negative electrode and the like), so that the first efficiency (short for first efficiency) of the lithium ion battery with the negative electrode can be effectively improved, and the cycle performance is improved. The calculation of the lithium supplementing amount is taken as one of important control parameters, and if the local lithium supplementing amount is higher, the problem of local lithium precipitation can be caused; if the local lithium supplementing amount is low, the first effect cannot meet the requirement, so that the accurate test of the lithium supplementing amount of the pole piece is required.

In the related art, the electrode membrane is adopted to react with the solution, so that the acid-base value (PH value) of the reaction solution is detected, and the lithium supplementing amount is determined according to the PH value. However, because the electrode membrane active materials have small amounts of acidic/alkaline components in different types of electrode membranes due to different formulation components, after the electrode membrane is dissolved by using the reaction solution, the PH test result of the reaction solution can be interfered by other acidic/alkaline components except lithium, so that the accuracy cannot be ensured, and the accuracy of the lithium supplementing amount is reduced.

Disclosure of Invention

The embodiment of the application provides a method and equipment for detecting the lithium supplementing amount, and the accuracy of the lithium supplementing amount is improved.

The technical scheme of the embodiment of the application is realized as follows:

in a first aspect, an embodiment of the present application provides a method for detecting a lithium supplementing amount, where the method includes: placing the film with the metal lithium into a container filled with a reaction solution, and obtaining a sample solution after a preset time period; the metal lithium comes from the pole piece; detecting the conductivity of a sample solution, and determining the conductivity of a reaction solution; and determining the lithium supplementing quantity of the unit area of the pole piece according to the conductivity of the reaction liquid.

According to the technical means, the electrode diaphragm is not required to be adopted for solution reaction, and the lithium supplementing amount is calculated by adopting a process before lithium supplementing of the electrode diaphragm, so that the electrode diaphragm is not damaged, the interference of other acidic/alkaline components except lithium in the PH value detection is reduced by detecting the conductivity of the reaction liquid, and the lithium supplementing amount of a unit area is determined by the conductivity of the reaction liquid, so that the accuracy of the lithium supplementing amount is improved.

In some embodiments, the first constant and the second constant are determined according to an area of the film, a volume of the reaction liquid, and a kind of the reaction liquid; according to the conductivity of the reaction liquid, determining the lithium supplementing quantity of the unit area of the pole piece, comprising the following steps: and determining the lithium supplementing amount according to the electric conductivity of the reaction liquid, the first constant and the second constant.

Through the technical means, the lithium supplementing quantity of the unit area of the pole piece can be rapidly and accurately determined according to the mathematical relationship among the conductivity of the reaction liquid, the first constant and the second constant.

In some embodiments, determining the amount of lithium replenishment based on the reaction liquid conductivity, the first constant and the second constant comprises: the difference between the reciprocal of the conductivity of the reaction solution and the second constant divided by the product of the first constant is used as the lithium supplementing amount.

By the technical means, the conductivity of the reaction solution, the first constant, the second constant and the lithium supplementing amount meet a certain linear relation, and the lithium supplementing amount per unit area can be accurately determined according to the linear relation.

In some embodiments, the number of films is at least two, the method further comprising: taking the average value of the lithium supplementing amounts corresponding to at least two films as a first lithium supplementing amount; and performing lithium supplementing operation on the polar plate according to the first lithium supplementing amount.

Through the technical means, the first lithium supplementing quantity is determined for the lithium supplementing quantities corresponding to the plurality of at least two films, so that errors caused by the lithium supplementing quantity of a single film can be avoided, and the accuracy of the first lithium supplementing quantity is improved.

In some embodiments, at least one film with metallic lithium is obtained; obtaining at least one film with metallic lithium, comprising: at least one adhesive tape sample is distributed along the axial direction and/or the axial section direction of a rolling roller for rolling the metal lithium and is attached to the roller surface of the rolling roller; applying a predetermined pressure to at least one tape sample such that the tape sample and the roll surface achieve adhesion of a predetermined area; at least one tape sample was peeled from the roll surface of the calender roll to obtain at least one film with metallic lithium.

Through the technical means, the film with metal lithium can be obtained rapidly, and the lithium supplementing quantity in the axial direction and/or the axial direction can be collected simultaneously to be adjusted properly, so that the requirement of lithium supplementing consistency in the axial direction and/or the axial direction can be met, and the interference of pole piece active substances on the test can be effectively avoided.

In some embodiments, the lateral fluctuation is determined according to the lithium replenishment amounts corresponding to at least two first tape samples in the axial direction; determining longitudinal fluctuation according to lithium supplementing amounts corresponding to at least two second adhesive tape samples in the axial tangential direction; and judging whether the lithium supplementing consistency is met according to the transverse fluctuation and the longitudinal fluctuation.

Through the technical means, whether the lithium supplementing consistency is met or not is determined according to the transverse fluctuation in the axial direction and the longitudinal fluctuation in the axial section direction, the consistency in the transverse direction can be fully considered, and the consistency in the longitudinal direction is considered, so that the accuracy of judging the lithium supplementing consistency is improved.

In some embodiments, if the lithium supplementing consistency is judged to be met according to the transverse fluctuation and the longitudinal fluctuation, determining a second lithium supplementing amount according to the lithium supplementing amounts respectively corresponding to at least two first adhesive tape samples in the axial direction and the lithium supplementing amounts respectively corresponding to at least two second adhesive tape samples in the axial section direction; and performing lithium supplementing operation on the polar plate according to the second lithium supplementing amount.

Through the technical means, the second lithium supplementing amount is determined according to the lithium supplementing amounts in the axial direction and the axial direction, so that the lithium supplementing amounts corresponding to the adhesive tape sample are relatively uniform and stable in the axial direction and the axial direction, and the consistency and the stability of lithium supplementing are improved.

In some embodiments, a target lithium replenishment amount corresponding to the lithium ion battery pole piece system is determined based on the lithium ion battery pole piece system and the lithium replenishment amount.

According to the technical means, the target lithium supplementing quantity corresponding to the lithium ion battery pole piece system is obtained according to the lithium ion battery pole piece system and the lithium supplementing quantity of the unit area of the pole piece, so that the lithium supplementing quantity meets different types of pole pieces, and the applicability of the lithium supplementing quantity is improved.

In a second aspect, embodiments of the present application provide a detection apparatus for a lithium supplementing amount, the apparatus including: a bracket; a tray supported on the bracket for placing a container for holding a reaction liquid; a support arm connected to the bracket; each support arm is provided with at least two fixing pieces for fixing each solution conductivity detector; detecting the conductivity of the sample solution in the container through each solution conductivity detector to determine the conductivity of the reaction solution; the conductivity of each reaction solution is used for determining the lithium supplementing quantity of the unit area of the pole piece.

Through the technical means, the conductivity of the sample solution after the reaction of the reaction solution in the container and the film with the metal lithium can be detected through the solution conductivity detectors on the fixing piece, so that the requirement for testing a plurality of sample solutions simultaneously is met, and the testing efficiency is improved.

In some embodiments, the bracket includes a base, and a post vertically connected to the base; the bracket is combined with the support arm to provide support for the solution conductivity detector; the tray is connected on the pillar, and the plane that the tray is located is parallel with the plane that the base is located, and the pillar provides the support for the tray.

Through the technical means, the base is vertically connected with the support column, so that the stability of the support column can be maintained, and the support arm is fixed on the support frame, so that the support can be provided for the solution conductivity detector, and the stability of the solution conductivity detector is maintained.

In some embodiments, each mount comprises a support plate vertically fixed to the support arm, and a telescoping arm fixed to the support plate; the telescopic arm is connected with the solution conductivity detector; the plane of the telescopic arm is parallel to the plane of the supporting plate; the telescoping arm is used to move the solution conductivity detector along the location of the container to move the solution conductivity detector into the sample solution in the container.

By the technical means, the stability of the solution conductivity detector can be maintained by fixing the telescopic arm connected with the solution conductivity detector on the supporting plate, so that the telescopic arm can accurately move the solution conductivity detector into the sample solution in the container.

In some embodiments, each mount further comprises: a slide rail of the firmware on the support plate; the plane of the sliding rail is parallel to the plane of the supporting plate; the slide guides guide the telescopic arm to move along the position of the container.

Through above-mentioned technical means, through setting up the slide rail in the backup pad, can maintain the stability of scalable arm to guide scalable arm to remove along the position that the container is located, avoid scalable arm to produce unstable and the phenomenon that rocks at the removal in-process.

In some embodiments, the base is provided with a display screen and at least one operational control; the display screen is used for displaying the conductivity of the reaction liquid obtained by detecting the conductivity of the sample solution in the container by the solution conductivity detector; the operation control is used for performing operation control on the telescopic arm on the fixed part.

Through the technical means, the visualization of the detection parameters can be realized through the display screen, and the control of the detection equipment for lithium supplementing quantity can be conveniently realized through the operation control, so that the operation is simple, and the practicability of the equipment is improved.

In some embodiments, the tray includes at least two placement holes, each for placement of a container.

Through the technical means, the plurality of placing holes for placing the containers are formed in the tray, so that the requirement for testing a plurality of sample solutions can be met, and the testing efficiency is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and, together with the description, serve to explain the technical aspects of the application. It is apparent that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

The flow diagrams depicted in the figures are exemplary only, and do not necessarily include all of the elements and operations/steps, nor must they be performed in the order described. For example, some operations/steps may be decomposed, and some operations/steps may be combined or partially combined, so that the order of actual execution may be changed according to actual situations.

Fig. 1 is a schematic flow chart of an alternative method for detecting lithium supplementing amount according to an embodiment of the present application;

fig. 2 is a second flow chart of an alternative method for detecting lithium supplementing amount according to an embodiment of the present application;

fig. 3 is a flow chart III of an alternative method for detecting lithium supplementing amount according to an embodiment of the present application;

FIG. 4 is a schematic illustration of an alternative film with metallic lithium acquisition provided in an embodiment of the present application;

fig. 5 is a flow chart diagram of an alternative method for detecting lithium supplementing amount according to an embodiment of the present application;

FIG. 6 is a front view of an alternative lithium replenishment amount detection device provided in an embodiment of the present application;

FIG. 7 is a left side view of an alternative lithium replenishment amount detection device in accordance with an embodiment of the present application;

fig. 8 is a top view of an alternative lithium supplementing amount detection device according to an embodiment of the present application.

In the drawings, the drawings are not drawn to scale.

Reference numerals in the specific embodiments are as follows:

1-a bracket; 11-a base; 12-a pillar; 111-a display screen; 112-an operation control;

2-a tray; 21-placing holes;

3-a support arm; 31-a fixing piece; 311-a support plate; 312—a telescopic arm; 313—a solution conductivity detector; 314—a slide rail;

4-container.

Detailed Description

In order to make the objects, technical solutions and advantages of the present embodiment more apparent, the specific technical solutions of the present application will be described in further detail below with reference to the accompanying drawings in the present embodiment. The following examples are illustrative of the present application, but are not intended to limit the scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing the embodiments only and is not intended to be limiting of the application.

In the following description reference is made to "some embodiments," "this embodiment," and examples, etc., which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with one another without conflict.

If a similar description of "first/second" appears in the application document, the following description is added, in which the terms "first/second/third" are merely distinguishing between similar objects and not representing a particular ordering of the objects, it being understood that the "first/second/third" may be interchanged with a particular order or precedence, where allowed, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

The term "and/or" in this embodiment is merely an association relationship describing an associated object, and indicates that three relationships may exist, for example, object a and/or object B may indicate: there are three cases where object a alone exists, object a and object B together, and object B alone exists.

In order to better understand the detection method of the lithium supplementing amount provided in the embodiment of the present application, before the technical solution of the embodiment of the present application is introduced, an application background and related technologies are described.

Lithium batteries are high-energy density, high-voltage, lightweight secondary batteries, and are widely used in the fields of portable electronic devices, electric vehicles, energy storage systems, and the like.

By way of example, the power utilization device to which the lithium battery may be applied may take various forms, such as a cellular phone, a portable device, a notebook computer, an electric car, a ship, a spacecraft, an electric toy, and an electric tool, etc., for example, a spacecraft including an airplane, a rocket, a space plane, and a spacecraft, etc., an electric toy including a stationary or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric plane toy, etc., an electric tool including a metal cutting electric tool, a grinding electric tool, an assembling electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, an electric planer, etc., to which the embodiment of the present application is not limited in any way.

Further, the basic principle of operation of lithium batteries is that upon charging, lithium ions are released from the positive electrode (typically an oxide material) and migrate through the electrolyte layer into the negative electrode (typically a graphite material) to form a lithium intercalation compound. During discharge, lithium ions are released from the negative electrode, migrate through the electrolyte layer, and into the positive electrode, forming a lithium intercalation compound. This charge and discharge process allows the lithium battery to be reused.

The battery electrode sheet is one of the important components constituting the battery, and it is generally referred to as a positive electrode sheet and a negative electrode sheet of the battery:

positive plate: the positive electrode sheet is one polarity in a battery and is generally composed of a thin film containing a positive electrode active material (e.g., a positive electrode material). The positive electrode sheet is a portion that receives current and accommodates lithium ions during charge and discharge. When the battery is discharged, lithium ions are deintercalated from the positive electrode sheet, and electrons are released from the positive electrode active material to form a current.

Negative electrode plate: the negative electrode sheet is another polarity in a battery, and is generally composed of a thin film containing a negative electrode active material (e.g., a negative electrode material). During charge and discharge, the negative electrode sheet is a portion that discharges current and accommodates lithium ions. When the battery is charged, external current passes through the battery, lithium ions are inserted into the negative electrode sheet, and chemical reaction with the negative electrode active material occurs.

In the related art, in order to solve the problem of reduction of the initial efficiency of the battery caused by lithium ion consumption due to generation of an SEI film (Solid Electrolyte Interphase, solid electrolyte interface) in the initial efficiency process of the battery, a pole piece lithium supplementing technology is introduced. The pole piece lithium supplementing technology is a method for solving the problem of lithium ion consumption in the initial effect process of the battery. During the first charge and discharge cycle of the battery, a SEI film is formed due to the reaction between the battery positive electrode material and the electrolyte layer. The formation process of the SEI film consumes a part of lithium ions, so that the phenomenon of first effect reduction of the battery occurs in the first charge and discharge cycle. In order to reduce lithium ion loss caused by SEI film formation, a pole piece lithium supplementing technology can be adopted in the battery manufacturing process. The pole piece lithium supplementing technology is to supplement a certain amount of lithium ions to the negative electrode of the battery through a specific lithium supplementing process in the manufacturing process of the battery. In this way, the battery negative electrode has been partially replenished with lithium ions during the first charge-discharge cycle, thereby reducing loss of lithium ions when forming the SEI film.

Through the pole piece lithium supplementing technology, the phenomenon of first effect reduction of the battery can be effectively reduced, and the first charge and discharge efficiency and the performance stability of the battery are improved. The method has important significance for improving the energy density, the cycle life and the reliability of the lithium ion battery, and particularly has application scenes such as electric vehicles and the like which need high-performance first charge and discharge efficiency. Meanwhile, the pole piece lithium supplementing technology is also used for accurately controlling the lithium supplementing amount and the lithium supplementing rate, so that the problems of overcharge or overheat of the battery caused by excessive lithium supplementing are avoided, and the safety and the stability of the battery are ensured.

For the lithium supplementing process of the battery pole piece, ensuring the accuracy of the lithium supplementing amount is very important. If the local lithium supplement amount is too high, a problem of local lithium precipitation is caused, which may cause precipitation of lithium metal in the battery during charging, resulting in safety risk. If the local lithium supplementing amount is low, the first-effect performance of the battery cannot meet the requirement, and the performance stability and the cycle life of the battery are affected.

The traditional weighing method has certain problems in lithium supplementing amount test: on the one hand, the weight fluctuation of the pole piece can influence the accuracy of the lithium supplementing amount, because the lithium supplementing amount is a small value relative to the weight of the pole piece, and is difficult to accurately measure by a traditional weighing method. On the other hand, the number of lithium supplementation bases is low relative to the weight of the pole piece, which makes the traditional weighing method unsuitable for testing the lithium supplementation of the pole piece.

Based on this, the embodiment of the application provides a method for detecting the lithium supplementing amount, and the main idea of the method is that: firstly, putting a film with metallic lithium into a container filled with a reaction solution, and obtaining a sample solution after a preset time period; then, detecting the conductivity of the sample solution to determine the conductivity of the reaction solution; and finally, determining the lithium supplementing quantity of the pole piece according to the conductivity of the reaction liquid. Therefore, the lithium supplementing amount is calculated through a process before the lithium supplementing of the electrode membrane, the electrode membrane is protected from being damaged, and the interference of other acidic/alkaline components except lithium during the PH value detection is reduced through detecting the conductivity of the reaction liquid, so that the accuracy of the lithium supplementing amount is improved.

The technical scheme of the present application will be described in detail with reference to the accompanying drawings.

Referring to fig. 1, fig. 1 is a schematic flow chart of an alternative method for detecting a lithium supplementing amount according to an embodiment of the present application, where the method includes S101 to S103:

s101, putting a film with metal lithium into a container filled with a reaction solution, and obtaining a sample solution after a preset time period; the metallic lithium comes from the pole piece.

In the embodiment of the application, the metal lithium is placed in a container filled with the reaction liquid, so that the metal lithium is ensured to be fully contacted with the reaction liquid, and the metal lithium is reacted with the reaction liquid in a preset time period. During the reaction, lithium ions dissolve from the metallic lithium into the reaction solution, forming a solution of lithium ions, i.e., a sample solution.

In the embodiment of the application, the sample solution is a mixed solution with lithium metal.

In the embodiment of the present application, the reaction solution is generally a solution for reacting with lithium metal in the detection process of the lithium supplementing amount. The reaction liquid may be an electrolyte, a battery electrolyte or other reactant-containing liquid. The composition of the reaction solution depends on the specific experimental purpose and requirements, and it is generally necessary to design an appropriate reaction solution according to the experimental needs.

In the embodiment of the application, the reaction solution may be a single chemical solution or a complex solution formed by mixing multiple chemical substances.

The reaction solution may be a mixed solution of at least one of ionized water, hydrochloric acid, sulfuric acid, acetic acid, nitric acid and phosphoric acid, which is not limited in any way in the embodiment of the present application.

In the embodiment of the application, the volume of the reaction solution can influence the stability of the reaction between the metallic lithium and the reaction solution to a certain extent. In the actual detection process, the volume of the reaction solution can be determined in combination with specific experimental conditions.

In the embodiment of the present application, the volume of the reaction solution is 50 to 1000ml, which is not limited in any way.

It can be understood that the volume of the reaction liquid is set in a proper interval range, so that the situation that the metal lithium on the film cannot fully react due to too little reaction liquid and the measured parameter value is too low to be detected due to too much reaction liquid can be avoided.

In this embodiment of the present application, the preset time period is a preset time interval.

In the embodiment of the application, the preset time period is determined according to the chemical reaction time of the lithium metal and the reaction liquid. In a preset time period, the metal lithium and the reaction liquid can be ensured to fully react, and lithium ions are ensured to be dissolved into the reaction liquid from the metal lithium, so that a sample solution with lithium ions is formed.

It can be understood that by setting a proper preset time period, the metal lithium can be ensured to fully react with the reaction liquid, so that the accuracy of the conductivity of the reaction liquid is ensured in the subsequent process of detecting the conductivity of the sample solution, thereby improving the accuracy of the lithium supplementing amount.

In the present embodiment, the lithium metal comes from the pole piece.

In embodiments of the present application, the metallic lithium in the pole pieces is adhered by a film, and these pole pieces with metallic lithium may be lithium metal electrode materials for batteries or other applications, such as the negative electrode of lithium ion batteries (i.e., lithium metal negative electrode).

In the examples herein, a tape (film) with metallic lithium was put into a container containing a reaction solution, and a sample solution was obtained after a preset period of time.

The film with metallic lithium may be any shape. The film may be circular, square, polygonal, etc., and the shape of the film is not limited in this embodiment, and may be specifically selected according to the actual application scenario.

S102, detecting the conductivity of the sample solution, and determining the conductivity of the reaction solution.

In the embodiment of the application, the metal lithium is placed in a container filled with a reaction solution, and in a preset period of time, the metal lithium reacts with the reaction solution, and lithium ions may be dissolved into the reaction solution from the metal lithium to form a solution of lithium ions. After the preset period of time is over, the conductivity of the sample solution is detected by a conductivity measuring device (also called a solution conductivity detector), so that the conductivity of the reaction solution is determined.

The conductivity of the reaction solution reflects the ability of the conductor to conduct current per unit length and per unit cross-sectional area, which is related to the concentration of the electrolyte contained in the solution. In the detection process of the lithium supplementing amount, if a large amount of lithium ions are contained in the reaction liquid, the conductivity of the reaction liquid of the sample solution is higher; conversely, if the lithium ions dissolve less, the conductivity of the reaction solution will be lower.

S103, determining the lithium supplementing quantity of the unit area of the pole piece according to the conductivity of the reaction liquid.

In the embodiment of the application, after the conductivity of the reaction solution of the sample solution is determined, the lithium supplementing amount of the unit area of the pole piece is determined according to the conductivity of the reaction solution.

In the embodiment of the present application, the lithium supplementing amount per unit area is the lithium supplementing amount per unit.

In some embodiments of the present application, the amount of lithium supplementation is inversely related to the conductivity of the reaction solution.

In the embodiment of the application, the conductivity of the reaction solution is inversely related to the resistivity of the reaction solution, so that the lithium supplementing amount is positively related to the resistivity of the reaction solution.

In the embodiment of the application, after the lithium supplementing amount of the pole piece is determined, the pole piece of the lithium battery is subjected to lithium supplementing operation according to the lithium supplementing amount.

It can be understood that the lithium supplementing amount of the unit area of the pole piece can be determined through the calculation relation between the conductivity of the reaction liquid and the lithium supplementing amount of the unit area, so that the accuracy of the lithium supplementing amount is improved, and the efficiency of determining the lithium supplementing amount is improved.

In some embodiments of the present application, the method for detecting the lithium supplementing amount further includes: the first constant and the second constant are determined according to the area of the film, the volume of the reaction liquid, and the kind of the reaction liquid.

In the embodiment of the present application, the first constant and the second constant are fixed values related to the kind and the volume of the reaction liquid.

In the present embodiment, the area of the film is related to the shape of the film.

In the embodiment of the present application, the first constant and the second constant are determined together by the area of the film, the volume of the reaction liquid, and the kind of the reaction liquid.

In the embodiment of the present application, the first constant and the second constant may be obtained by fitting experimental data.

It can be understood that the lithium supplementing amount of the unit area of the pole piece can be rapidly and accurately determined according to the mathematical relationship among the conductivity of the reaction liquid, the first constant and the second constant.

In some embodiments of the present application, determining the lithium supplement amount per unit area of the pole piece in S103 according to the conductivity of the reaction solution may include: and determining the lithium supplementing amount according to the electric conductivity of the reaction liquid, the first constant and the second constant.

In the embodiment of the present application, the resistivity of the reaction solution, the first constant, the second constant, and the lithium supplementing amount satisfy the formula (1):

（1）

in the case of the formula (1),the resistivity of the reaction liquid is expressed,a first constant is indicated and a second constant is indicated,a second constant is indicated as such,indicating the amount of lithium supplement.

In some embodiments of the present application, the inverse of the conductivity of the reaction solution is calculated according to equation (1) And a second constantDivided by a first constantIs used as the lithium supplementing amount.

In the embodiment of the present application, first, the resistivity of the reaction solution is determined based on the conductivity of the reaction solutionThe method comprises the steps of carrying out a first treatment on the surface of the Then, according to the reaction liquid resistivity by the formula (1)First constantAnd a second constantDetermining the lithium supplementing amount。

In the embodiment of the application, for the formula (1), data fitting is performed through a large amount of experimental data, so as to determine the first constant and the second constant.

It can be understood that the conductivity of the reaction solution, the first constant, the second constant and the lithium supplementing amount satisfy a certain linear relationship, and according to the linear relationship, the lithium supplementing amount per unit area can be accurately determined.

In some embodiments of the present application, the number of films is at least two.

In some embodiments of the present application, the method for detecting the lithium supplementing amount further includes:

taking the average value of the lithium supplementing amounts corresponding to at least two films as a first lithium supplementing amount;

and performing lithium supplementing operation on the polar plate according to the first lithium supplementing amount.

In the embodiment of the application, when the number of the films is at least two, the metal lithium carried by each film is put into a container filled with the reaction solution to obtain sample solutions corresponding to each film, and conductivity detection is performed on each sample solution to obtain the conductivity of the reaction solution of each sample solution, so that the lithium supplementing amount corresponding to each film is obtained. Further, a first lithium replenishment amount is determined based on the lithium replenishment amounts corresponding to the respective ones of the at least two films.

The lithium supplementing amount corresponding to each film can be averaged to obtain a first lithium supplementing amount, and the lithium supplementing operation is performed on the pole piece according to the first lithium supplementing amount.

It should be noted that, the first lithium supplementing amount may be an average value of lithium supplementing amounts corresponding to at least two films, or may be a maximum value, a minimum value, a median value, etc. of lithium supplementing amounts corresponding to at least two films, which is not limited in this application, and may be specifically selected according to an actual scene.

It can be appreciated that by determining the first lithium-compensating amount for the lithium-compensating amounts corresponding to the plurality of at least two films, an error caused by the lithium-compensating amount of a single film can be avoided, and thus the accuracy of the first lithium-compensating amount can be improved.

In some embodiments of the present application, implementation after determining the lithium supplement amount per unit area of the pole piece according to the conductivity of the reaction solution in S103 may include: and determining a target lithium supplementing amount corresponding to the lithium ion battery pole piece system according to the lithium ion battery pole piece system and the lithium supplementing amount.

In the embodiments of the present application, the lithium ion battery pole piece system is also referred to as a battery pole piece system.

In the embodiment of the application, the pole piece system of the lithium ion battery is equivalent to different types of pole pieces, and the lithium supplementing amount required by different systems is different.

In the embodiment of the application, since the lithium supplementing amounts corresponding to different battery pole pieces are different, the lithium supplementing amounts can be adaptively adjusted according to the lithium ion battery pole piece system, so that the target lithium supplementing amount corresponding to the lithium ion battery pole piece system is determined.

It can be understood that the target lithium supplementing quantity corresponding to the lithium ion battery pole piece system is obtained according to the lithium ion battery pole piece system and the lithium supplementing quantity of the unit area of the pole piece, so that the lithium supplementing quantity meets different types of pole pieces, and the applicability of the lithium supplementing quantity is improved.

In the embodiment of the application, a method for detecting the lithium supplementing amount is provided, firstly, an adhesive tape with metal lithium is put into a container filled with a reaction solution, and a sample solution is obtained after a preset time period; detecting the conductivity of a sample solution, and determining the conductivity of a reaction solution; and determining the lithium supplementing quantity of the unit area of the pole piece according to the conductivity of the reaction liquid. According to the technical scheme, the electrode diaphragm is not required to be adopted for solution reaction, but the calculation of the lithium supplementing amount is carried out by adopting a process before lithium supplementing of the electrode diaphragm, so that the electrode diaphragm is not damaged, the acid/alkaline component interference except lithium is reduced in the PH value detection process by detecting the conductivity of the reaction liquid, the lithium supplementing amount of the unit area is determined by the calculation relation between the conductivity of the reaction liquid and the lithium supplementing amount of the unit area, and the accuracy of the lithium supplementing amount is improved.

In some embodiments of the present application, as shown in fig. 2, before S101, the method for detecting the lithium supplementing amount further includes S104: at least one film with metallic lithium is obtained.

In some embodiments of the present application, as shown in fig. 3, the implementation of obtaining at least one film with metallic lithium in S104 may include: s1041 to S1043:

s1041, at least one adhesive tape sample is distributed along the axial direction and/or the axial section direction of a rolling roller for rolling the metallic lithium respectively and is attached to the roller surface of the rolling roller.

S1042, applying preset pressure to at least one adhesive tape sample, so that the adhesive tape sample and the roller surface reach adhesion of preset area.

S1043, peeling at least one adhesive tape sample from the roller surface of the calendaring roller to obtain at least one film with metal lithium.

In embodiments of the present application, the tape sample may be an adhesive tape or other suitable material. It should be noted that the size and shape of the tape sample should be designed according to the actual needs to ensure matching with the calender rolls.

In this embodiment of the present application, the preset area is a preset value, and the preset area is consistent with the unit area of the film.

In the embodiment of the present application, the axial direction of the calender roll is also referred to as the lateral direction of the calender roll, and the axial section direction of the calender roll is also referred to as the longitudinal direction of the calender roll.

In the embodiment of the application, the adhesive tape sample is distributed along the axial direction and/or the axial section direction of the calendaring roller for calendaring the metal lithium and is attached to the roller surface, so that the surface of the adhesive tape sample can be fully contacted with the surface of the calendaring roller, that is, the metal lithium can be fully contacted with the adhesive tape sample.

In an embodiment of the present application, a preset pressure is applied to at least one tape sample, so that the tape sample and the roller surface reach adhesion of a preset area. By applying pressure, a sufficient contact force can be generated between the tape sample and the calender roll, thereby promoting the transfer and adhesion of the metallic lithium to the tape, that is, the contact between the metallic lithium and the tape sample can be made more intimate, facilitating the transfer of the metallic lithium.

In embodiments of the present application, at least one tape sample is peeled from the roll surface of the calender roll under conditions that ensure that the metallic lithium is not damaged or lost, to obtain at least one film with metallic lithium.

It can be appreciated that by distributing at least one tape sample along the axial direction and/or the axial direction of the calender roll for performing the calendering operation on the metal lithium, the film with the metal lithium can be obtained rapidly, and the lithium supplementing amount in the axial direction and/or the axial direction can be collected at the same time for proper adjustment, so that the requirement of lithium supplementing consistency in the axial direction and/or the axial direction can be satisfied, and in addition, the interference of the pole piece active substance on the test can be effectively avoided.

Exemplary, fig. 4 is a schematic diagram of an alternative method for obtaining a film with metal lithium according to an embodiment of the present application, as shown in fig. 4, a round film (adhesive tape) with a specific area (i.e., a preset area) is torn off from a release paper, then the adhesive tape is attached to a roll surface, and is lightly pressed, so that the adhesive surface is fully combined with a lithium layer (i.e., a lithium film), and the whole wafer adhesive tape is peeled off from the roll surface, so as to obtain the film with metal lithium (adhesive tape with metal lithium).

determining transverse fluctuation according to lithium supplementing amounts corresponding to at least two first adhesive tape samples in the axial direction;

determining longitudinal fluctuation according to lithium supplementing amounts corresponding to at least two second adhesive tape samples in the axial tangential direction;

and judging whether the lithium supplementing consistency is met according to the transverse fluctuation and the longitudinal fluctuation.

In the embodiment of the application, after the lithium supplementing amounts corresponding to at least two adhesive tape samples are obtained, transverse fluctuation is determined according to the lithium supplementing amounts corresponding to at least two first adhesive tape samples in the axial direction, longitudinal fluctuation is determined according to the lithium supplementing amounts corresponding to at least two second adhesive tape samples in the axial section direction, and whether the lithium supplementing consistency is met is judged according to the transverse fluctuation and the longitudinal fluctuation.

It can be understood that whether the lithium supplementing consistency is satisfied is determined according to the transverse fluctuation in the axial direction and the longitudinal fluctuation in the axial section direction, so that the consistency in the axial direction can be fully considered, and the consistency in the axial section direction is considered, thereby improving the accuracy of judging the lithium supplementing consistency.

It should be noted that, the uniformity of lithium replenishment is an important control parameter in the lithium replenishment process, which affects whether the distribution of the lithium replenishment amount corresponding to the tape sample is uniform and stable. If the lithium supplementing consistency is not good, the battery performance is possibly unstable or inconsistent, and the working performance and the service life of the battery are affected. Therefore, evaluation and optimization of lithium replenishment uniformity are very important to ensure performance and stability of the battery.

In the embodiment of the application, the magnitude of the transverse fluctuation can be calculated according to the lithium supplementing amounts corresponding to at least two first adhesive tape samples in the axial direction.

The lateral fluctuation refers to a difference in lithium supplementing amount of at least two first tape samples in the axial direction.

Illustratively, at least two first tape samples corresponding in the lateral direction are selected from the same batch of tape samples, and their lithium replenishment amounts are measured. Then, the difference in lithium replenishment amount between these first tape samples was calculated to obtain the magnitude of the lateral fluctuation.

In the embodiment of the present application, the calculation of the lateral fluctuation may be implemented by calculating statistical indexes such as standard deviation, variance, mean, etc., which is not limited in this embodiment of the present application, and may specifically be selected according to actual situations.

In the embodiment of the application, the magnitude of the longitudinal fluctuation can be calculated according to the lithium supplementing amount corresponding to at least two second adhesive tape samples in the axial tangential direction.

The longitudinal fluctuation refers to a difference in lithium supplementing amount of at least two second tape samples in the axial tangential direction.

Illustratively, at least two second tape samples corresponding in the axial tangential direction are selected from the same batch of tape samples, and their lithium supplementation amounts are measured. Then, the difference in lithium replenishment amount between these second tape samples was calculated to obtain the magnitude of longitudinal fluctuation.

In the embodiment of the present application, the calculation of the longitudinal fluctuation may also be implemented by calculating statistical indexes such as standard deviation, variance, mean, etc., which is not limited in this embodiment of the present application, and may specifically be selected according to actual situations.

In the embodiment of the application, the uniformity of lithium supplementing refers to that the lithium supplementing amounts corresponding to the tape samples at different positions or directions are kept relatively consistent, namely, the fluctuation of the lithium supplementing amounts in the axial direction and the axial tangential direction is smaller, and the difference is smaller. If the fluctuation of the axial direction and the axial tangential direction is smaller, the lithium supplementing quantity corresponding to the adhesive tape sample is relatively consistent, and the lithium supplementing consistency requirement is met.

That is, by comparing the magnitudes of the lateral and longitudinal undulations, it can be determined whether the amounts of lithium replenishment corresponding to the tape samples are relatively uniform. If the fluctuation of the axial direction and the axial tangential direction is smaller, namely the difference of the lithium supplementing quantity corresponding to the adhesive tape sample is smaller, the lithium supplementing process is relatively consistent, and the lithium supplementing consistency requirement is met. Conversely, if the lateral or longitudinal fluctuations are large, it may be necessary to optimize the relevant process or adjust the operating parameters to improve lithium replenishment consistency.

It can be understood that if the fluctuation of the axial direction and the axial direction is found to be larger when the uniformity of lithium supplement is judged, that is, the difference of the lithium supplement between different adhesive tape samples is larger, the relative process is further optimized or the operation parameters are adjusted to ensure that the lithium supplement amounts of the adhesive tape samples are relatively uniform, so that the uniformity of lithium supplement is improved, a more stable and uniform lithium supplement effect can be obtained, and the performance and stability of the battery are improved.

In some embodiments of the present application, the method for detecting the lithium supplementing amount further includes: if the lithium supplementing consistency is judged to be met according to the transverse fluctuation and the longitudinal fluctuation, determining a second lithium supplementing amount according to the lithium supplementing amounts respectively corresponding to at least two first adhesive tape samples in the axial direction and the lithium supplementing amounts respectively corresponding to at least two second adhesive tape samples in the axial section direction; and performing lithium supplementing operation on the polar plate according to the second lithium supplementing amount.

In this embodiment of the present application, when it is determined that the lithium supplementing amounts corresponding to the at least two tape samples respectively meet the lithium supplementing consistency according to the lateral fluctuation and the longitudinal fluctuation, the second lithium supplementing amount may be further determined according to the lithium supplementing amounts corresponding to the at least two first tape samples respectively in the axial direction and the lithium supplementing amounts corresponding to the at least two second tape samples respectively in the axial direction.

In the embodiment of the application, the lithium supplementing operation on the polar plate includes two implementation modes:

mode 1, taking the average value of lithium supplementing amounts corresponding to at least two films as a first lithium supplementing amount; and performing lithium supplementing operation on the polar plate according to the first lithium supplementing amount.

Mode 2, under the condition that the lithium supplementing consistency is met, determining a second lithium supplementing amount according to the lithium supplementing amounts respectively corresponding to at least two first adhesive tape samples in the axial direction and the lithium supplementing amounts respectively corresponding to at least two second adhesive tape samples in the axial section direction; and performing lithium supplementing operation on the polar plate according to the second lithium supplementing amount.

In an embodiment of the present application, determining the second lithium supplementing amount according to the lithium supplementing amounts respectively corresponding to the at least two first tape samples in the axial direction and the lithium supplementing amounts respectively corresponding to the at least two second tape samples in the axial direction may include the following steps:

1) Judging whether the consistency of lithium supplement is satisfied:

in this embodiment of the present application, first, according to the lithium supplementing amounts corresponding to at least two first tape samples in the axial direction and at least two second tape samples in the axial direction, average values of the lithium supplementing amounts corresponding to these tape samples are calculated respectively, and standard deviations or variances of the lithium supplementing amounts in the axial direction and the axial direction are calculated, and if the fluctuation in the axial direction and the axial direction is smaller, it is indicated that the lithium supplementing amounts of the tape samples are relatively consistent, and the requirement of lithium supplementing consistency is satisfied.

2) Determining a second lithium supplementing amount:

in the embodiment of the present application, if the requirement of uniformity of lithium replenishment is satisfied, that is, fluctuation in the axial direction and the axial direction is small, an average value of the lithium replenishment amounts in the axial direction and the axial direction may be used as the determination value of the second lithium replenishment amount.

It will be appreciated that the second amount of lithium is determined based on the amounts of lithium in the axial and tangential directions of the shaft, thus taking into account both the uniformity in the axial direction and the uniformity in the tangential direction of the shaft.

Specifically, first, the average value of at least two first tape samples in the axial direction is calculated as a determination value of the second lithium replenishment amount in the lateral direction from the respective lithium replenishment amounts of these first tape samples. In this way, the amount of lithium replenishment can be ensured to be relatively uniform in the axial direction.

Then, an average value of the second tape samples is calculated as a determined value of the second lithium supplementing amount in the axial direction based on the lithium supplementing amounts of the at least two second tape samples in the axial direction. In this way, the amount of lithium supplement can be ensured to be relatively uniform in the axial tangential direction.

Further, the obtained determined values in the axial direction and the axial direction are combined to obtain a final second lithium supplementing amount, and the final second lithium supplementing amount is used as a reference for subsequent lithium supplementing operation and is used for carrying out lithium supplementing operation on the pole piece.

3) And performing lithium supplementing operation on the pole piece according to the second lithium supplementing amount:

in the embodiment of the application, the second lithium supplementing amount is a unit lithium supplementing amount, and the target lithium supplementing amount corresponding to the lithium ion battery pole piece system is determined according to the lithium ion battery pole piece system and the lithium supplementing amount.

In the embodiment of the application, the lithium supplementing operation is performed on the pole piece according to the second lithium supplementing amount determining value. The lithium supplementing operation can be realized through a series of process steps so as to ensure that the metal lithium is fully embedded into the pole piece, thereby realizing the lithium supplementing operation on the pole piece.

It can be understood that through the above-mentioned flow, can ensure the stability and the uniformity of mending lithium process for the lithium quantity that the sticky tape sample corresponds is all relatively even and stable in axial and axial tangent plane direction, thereby improves the uniformity and the stability of mending lithium, and this helps improving performance and the stability of battery, and ensures that the quality of battery accords with the requirement.

Further, fig. 5 is a flow chart four of an alternative method for detecting a lithium supplementing amount according to an embodiment of the present application, and as shown in fig. 5, the method for detecting a lithium supplementing amount may include: s201 to S207:

s201, at least one film with metal lithium is obtained.

In the embodiment of the present application, implementation of S201 may include S2011 to S2013:

and S2011, at least one adhesive tape sample is distributed along the axial direction and/or the axial section direction of a calendaring roller for calendaring the metallic lithium respectively and is attached to the roller surface.

And S2012, applying preset pressure to at least one adhesive tape sample so that the adhesive tape sample and the roller surface reach adhesion of a preset area.

S2013, peeling at least one adhesive tape sample from the roller surface of the calendaring roller to obtain at least one film with metal lithium.

S202, placing the film with the metal lithium into a container filled with a reaction solution, and obtaining a sample solution after a preset time period.

S203, detecting the conductivity of the sample solution to determine the conductivity of the reaction solution.

In the embodiment of the present application, implementation of S203 may include S2031 to S2032:

s2031, determining a first constant and a second constant according to the area of the film, the volume of the reaction liquid, and the type of the reaction liquid.

S2032 is obtained by dividing the difference between the reciprocal of the conductivity of the reaction solution and the second constant by the product of the first constant.

S204, taking the average value of the lithium supplementing amounts corresponding to at least two films as a first lithium supplementing amount.

S205, determining transverse fluctuation according to lithium supplementing amounts corresponding to at least two first adhesive tape samples in the axial direction; determining longitudinal fluctuation according to lithium supplementing amounts corresponding to at least two second adhesive tape samples in the axial tangential direction; and judging whether the lithium supplementing consistency is met according to the transverse fluctuation and the longitudinal fluctuation.

And S206, if the lithium supplementing consistency is judged to be met according to the transverse fluctuation and the longitudinal fluctuation, determining a second lithium supplementing amount according to the lithium supplementing amounts respectively corresponding to at least two first adhesive tape samples in the axial direction and the lithium supplementing amounts respectively corresponding to at least two second adhesive tape samples in the axial section direction.

Wherein S204, S205 to S206 are parallel schemes, and after S203, S203 may be executed, or S205 to S206 may be executed.

S207, determining a target lithium supplementing amount corresponding to the lithium ion battery pole piece system according to the lithium ion battery pole piece system and the lithium supplementing amount (the first lithium supplementing amount or the second lithium supplementing amount).

It can be understood that, the technical scheme of the embodiment of the application does not need to adopt the electrode membrane to perform solution reaction, but adopts a process before lithium supplementation of the electrode membrane to calculate the lithium supplementation amount, so that the electrode membrane is not damaged, and the interference of other acidic/alkaline components except lithium in PH value detection is reduced by detecting the conductivity of the reaction solution, and the lithium supplementation amount of unit area is determined by the calculation relation between the conductivity of the reaction solution and the lithium supplementation amount of unit area, thereby improving the accuracy of the lithium supplementation amount.

In order to implement the method for detecting the amount of lithium supplement in the embodiment of the present application, the embodiment of the present application further provides a device for detecting the amount of lithium supplement, fig. 6 is a front view of an alternative device for detecting the amount of lithium supplement provided in the embodiment of the present application, fig. 7 is a left view of an alternative device for detecting the amount of lithium supplement provided in the embodiment of the present application, fig. 8 is a top view of an alternative device for detecting the amount of lithium supplement provided in the embodiment of the present application, as shown in fig. 6 to 8, the device 1000 for detecting the amount of lithium supplement includes:

a bracket 1;

a tray 2 supported on the bracket 1 for placing a container 4 for containing a reaction liquid;

a support arm 3 connected to the bracket 1; at least two fixing members 31 are provided on each arm 3 for fixing the respective solution conductivity detectors 313; detecting the conductivity of the sample solution after the reaction of the reaction solution in the container 4 and the film with the metal lithium by each solution conductivity detector 313 to determine the conductivity of the reaction solution; the conductivity of each reaction solution is used for determining the lithium supplementing quantity of the unit area of the pole piece.

In this embodiment, the tray 2 is placed on the support 1, and the support 1 provides support for the tray 2, and the tray 2 may be in a fixed state or in a rotating state.

It will be appreciated that when the tray 2 is rotatable, it is convenient for the person concerned to take the container 4 and to place the tape with metallic lithium in the container 4.

In this embodiment of the application, tray 2 connects perpendicularly on support 1, and support 1 provides support for tray 2, has improved tray 2's stability.

In some embodiments of the present application, the tray 2 comprises at least two placement holes 21, each placement hole 21 for placing a container 4.

In this embodiment of the present application, the tray 2 may include a plurality of placement holes 21, that is, a plurality of containers 4 may be placed in the tray 2, so that, by setting a plurality of placement holes 21 for placing the containers 4 in the tray 2, the requirement of testing a plurality of sample solutions at the same time may be satisfied, thereby improving the detection efficiency of the lithium supplementing amount.

In this embodiment, the support 1 is connected with a support arm 3, at least two fixing members 31 are disposed on the support arm 3, and the support arm 3 provides support for the fixing members 31.

In this embodiment, each fixing member 31 is provided with a solution conductivity detector 313, and the fixing member can move the solution conductivity detector 313 into the sample solution contained in the container 4 to perform conductivity detection, so as to determine the conductivity of the reaction solution.

In the embodiment of the present application, at least one support arm 3 is connected to the support 1, and each support arm 3 is provided with at least one fixing member 31, so that simultaneous detection of a plurality of sample solutions can be achieved.

It can be understood that the conductivity of the sample solution in the container can be detected simultaneously by each solution conductivity detector on the fixing piece, so that the requirement of simultaneously testing a plurality of sample solutions is met, and the testing efficiency is improved.

In some embodiments of the present application, the stand 1 includes a base 11, and a pillar 12 vertically connected to the base 11; the bracket 1 is combined with the support arm 3 to provide support for the solution conductivity detector 313; the pallet 2 is connected to a support 12, the plane of the pallet 2 being parallel to the plane of the base 11, the support 12 providing support for the pallet 2.

It will be appreciated that by vertically connecting the base 11 to the support post 12, stability of the support post 12 is maintained, and fixing the arm 3 to the support frame 1 provides support for the solution conductivity detector 313, thereby maintaining stability of the solution conductivity detector 313.

In some embodiments of the present application, each fixing member 31 includes a support plate 311 vertically fixed to the arm 3, and a telescopic arm 312 fixed to the support plate 311; the telescopic arm 312 is connected with a solution conductivity detector 313; the plane of the telescopic arm 312 is parallel to the plane of the support plate 311; the telescopic arm 312 is used to move the solution conductivity detector 313 down into the sample solution in the container 4 to detect the conductivity of the sample solution.

It will be appreciated that by fixing the telescopic arm 312 to which the solution conductivity detector 313 is attached to the support plate 311, the stability of the solution conductivity detector 313 can be maintained so that the telescopic arm 312 can accurately move the solution conductivity detector 313 down into the sample solution held in the container 4.

In some embodiments of the present application, each fastener 31 further comprises: a slide rail 314 fixed to the support plate 311; the plane of the slide rail 314 is parallel to the plane of the support plate 311; slide 314 provides support for telescoping arm 312 and guides telescoping arm 312 downward.

It can be appreciated that by providing the sliding rail 314 on the supporting plate 311, support can be provided for the telescopic arm 312, so as to maintain the stability of the telescopic arm 312, and thus guide the telescopic arm 312 to move downward, and avoid the unstable and swaying phenomenon of the telescopic arm 312 during the moving process.

In some embodiments of the present application, the base 11 is provided with a display 111 and at least one operating control 112; the display screen 111 is used for displaying the conductivity of the reaction solution obtained by detecting the conductivity of the sample solution by the solution conductivity detector 313; the operation control 112 is used for operation control of the telescopic arm 312 on the mount 31.

It can be appreciated that, through the display screen 111, the visualization of the detection parameters can be realized, and the control of the detection device for the lithium supplementing amount can be facilitated through the operation control 112, so that the operation is simple, and the practicability of the device is improved.

Illustratively, the telescoping arm 312 is controlled by an operating control to move the solution conductivity detector 313 downwardly into the sample solution held by the container 4, and the arm 3 is controlled by an operating control to horizontally rotate so that the relevant person places the container 4 in the placement hole 21. The tray 2 can be controlled to horizontally rotate by operating the control, so that the relevant personnel can put the adhesive tape with the metal lithium in the container 4. The embodiment of the application does not limit the control functions which can be realized by the operation control, and can be specifically selected according to the actual application scene.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present application are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), if the specific posture is changed, the directional indicators correspondingly change, and the connection may be a direct connection or an indirect connection.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to the specific circumstances.

In the following, an exemplary application of the embodiments of the present application in a practical application scenario will be described.

In the embodiment of the application, a method for detecting the lithium supplementing amount is provided, and in the embodiment of the application, a metal lithium raw material is pressed into a film (also called a lithium film) under the action of rolling, adhered to the surface of a rolling roller, and then transferred to an electrode plate. Sampling by a method of sticking a tape (corresponding to a tape sample) on the surface of a calendaring roller, putting the tape sample with the metal lithium into a container filled with a reaction solution, and fully reacting the metal lithium with the reaction solution to obtain a sample solution. Further, the conductivity of the sample solution is tested by using the lithium supplementing amount detection device in the embodiment of the application, and the lithium supplementing amount of the unit area of the pole piece is obtained according to the conductivity value of the sample solution. The detection method for the lithium supplementing quantity can realize accurate test of the lithium supplementing quantity of the pole piece, and is simple to operate.

It can be appreciated that the method for detecting the lithium supplementing amount provided by the embodiment of the application can select mild reaction liquid, does not need to add reaction liquid with high reactivity with metal lithium such as strong acid, and avoids the safety risk when the metal lithium is dissolved, thereby improving the accuracy of the lithium supplementing amount.

The method for detecting the lithium supplementing amount provided by the embodiment of the application specifically comprises the following steps: firstly, placing a wafer adhesive tape (namely a film) stuck with metal lithium into a container filled with a reaction solution to prepare a mixed solution dissolved with the metal lithium; then, testing a specific parameter value in the mixed solution, wherein the parameter value is the conductivity of the mixed reaction solution; and finally, calculating the lithium supplementing weight of the area of the wafer according to the parameter value through a formula (1), namely the lithium supplementing amount of the unit area of the pole piece.

In the embodiment of the application, a method for obtaining a film with metal lithium is also provided, which is also called a sampling method for lithium supplementing weight test or a sampling method for sticking a wafer adhesive tape to roll surface metal lithium, and the method comprises the following steps:

1) And tearing the wafer adhesive tape with a specific area from the release paper.

2) And sticking the adhesive tape on the roller surface, and lightly pressing to ensure that the adhesive surface is fully combined with the lithium layer.

3) And stripping the whole wafer adhesive tape from the roll surface to obtain the film with the metal lithium.

It can be appreciated that by testing only the parameters of the metallic lithium sample, the embodiments of the present application can avoid the interference effects of other components in the pole piece, as compared to a method of directly transferring metallic lithium to the pole piece.

In an embodiment of the present application, a method for detecting a lithium supplementing amount is provided, including:

1) And placing the wafer tape stuck with the metal lithium into a container filled with a reaction solution to prepare a mixed solution (namely a sample solution) dissolved with the metal lithium.

2) And testing specific parameter values (namely the conductivity of the reaction solution) in the mixed solution.

3) And (3) calculating the lithium supplementing weight of the area of the wafer (namely, the lithium supplementing amount of the unit area of the pole piece) by using the parameter value through the formula (1).

In one embodiment, the method for detecting the lithium supplementing amount includes the following steps:

1) And attaching the round films 1, 2, 3 and 4 to the surface of the calendaring roller, lightly pressing the adhesive surface to fully combine the adhesive layer with the metal lithium, and taking down the 4 round films (namely the film with the metal lithium).

2) And dissolving the film 1, the film 2, the film 3 and the film 4 with the metal lithium in 100ml of deionized water reaction liquid, waiting for a preset time period, taking the reaction liquid after the metal lithium fully reacts with the reaction liquid, putting the reaction liquid into a container of a sample turntable (namely a tray) of test equipment, and testing the conductivity of the reaction liquid by a solution conductivity detector.

3) And (3) calculating the lithium supplementing weight (namely the lithium supplementing amount of the unit area of the pole piece) in the circular film area through the conductivity of the reaction liquid and the formula (1).

In the examples herein, table 1 is the test data for 4 round films under the same experimental conditions, each film's test data including its corresponding conductivity and lithium replenishment weight.

TABLE 1

The lithium supplementing amount detection method and the lithium supplementing amount detection device provided by the embodiment of the application have the beneficial effects that:

1) The method and the device for detecting the lithium supplementing quantity can accurately test the lithium supplementing quantity, are simple and quick, and the test device corresponding to the lithium supplementing quantity can simultaneously support the test of at least two samples, so that a plurality of samples can be tested simultaneously, the test efficiency is obviously improved, and the method and the device have an important guiding effect on the lithium supplementing process;

2) The detection method for the lithium supplementing amount can realize rapid sampling, can collect the lithium supplementing amount in the axial/axial tangential direction at the same time for proper adjustment, can meet the requirement of lithium supplementing consistency in the axial/axial tangential direction, and simultaneously avoids the interference of pole piece active substances on the test;

3) According to the detection method for the lithium supplementing amount, the reaction liquid can be prepared on the premise of safety and no risk, and the lithium supplementing amount of a specific area (unit area) of the battery pole piece can be accurately calculated through the conductivity value of the reaction liquid.

It should be noted that, when the lithium-supplementing amount detection device provided in the foregoing embodiment performs detection of the lithium-supplementing amount, only the division of the foregoing program modules is used as an example, in practical application, the foregoing processing allocation may be performed by different program modules according to needs, that is, the internal structure of the device is divided into different program modules, so as to complete all or part of the processing described above. In addition, the detection device for the lithium supplementing amount and the detection method embodiment for the lithium supplementing amount provided in the foregoing embodiments belong to the same concept, and specific implementation processes and beneficial effects thereof are detailed in the method embodiment and are not described herein again. For technical details not disclosed in the embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the embodiments, and are intended to be included within the scope of the present disclosure. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A method for detecting the amount of lithium supplement, the method comprising:

placing the film with the metal lithium into a container filled with a reaction solution, and obtaining a sample solution after a preset time period; the metal lithium on the film is obtained by sticking the metal lithium in the pole piece through the calendaring operation of the calendaring roller;

detecting the conductivity of the sample solution to determine the conductivity of the reaction solution;

determining the lithium supplementing amount of the pole piece in unit area according to the conductivity of the reaction liquid;

the method further comprises the steps of:

determining a first constant and a second constant according to the area of the film, the volume of the reaction liquid and the type of the reaction liquid;

the method for determining the lithium supplementing amount of the pole piece in unit area according to the conductivity of the reaction liquid comprises the following steps:

determining the lithium supplementing amount according to the conductivity of the reaction liquid, the first constant and the second constant;

the determining the lithium supplementing amount according to the reaction liquid conductivity, the first constant and the second constant comprises the following steps:

dividing the difference between the inverse of the conductivity of the reaction solution and the second constant by the product of the first constant to obtain the lithium supplementing amount;

the number of films is at least two, the method further comprising:

Under the condition that the lithium supplementing consistency is judged to be met according to the transverse fluctuation and the longitudinal fluctuation of the lithium supplementing amounts corresponding to the at least two films, determining a second lithium supplementing amount according to the lithium supplementing amounts respectively corresponding to the at least two first adhesive tape samples in the axial direction and the lithium supplementing amounts respectively corresponding to the at least two second adhesive tape samples in the axial section direction; wherein the lateral fluctuations characterize differences in the axial direction of the amounts of lithium supplementation corresponding to the at least two films; the longitudinal fluctuation represents the difference of the lithium supplementing amounts corresponding to the at least two films in the axial tangent direction;

and carrying out lithium supplementing operation on the polar plate according to the second lithium supplementing amount.

2. The method of claim 1, wherein the number of films is at least two, the method further comprising:

and carrying out lithium supplementing operation on the polar plate according to the first lithium supplementing amount.

3. The method according to claim 1, wherein the method further comprises:

obtaining at least one film with metal lithium;

the obtaining at least one film with metallic lithium comprises:

At least one adhesive tape sample is distributed along the axial direction and/or the axial section direction of a rolling roller for rolling the metal lithium and is attached to the roller surface of the rolling roller;

applying a preset pressure to at least one adhesive tape sample, so that the adhesive tape sample and the roller surface reach adhesion of a preset area;

and stripping at least one adhesive tape sample from the roller surface of the calendaring roller to obtain the at least one film with metal lithium.

4. A method according to claim 3, characterized in that the method further comprises:

5. The method according to any one of claims 1 to 4, wherein after the determination of the lithium replenishment amount per unit area of the pole piece based on the reaction liquid conductivity, the method further comprises:

and determining a target lithium supplementing amount corresponding to the lithium ion battery pole piece system according to the lithium ion battery pole piece system and the lithium supplementing amount.