KR102523354B1 - Surface treatment method of electrode terminal for secondary battery and electrode terminal for secondary battery surface-treated using the same - Google Patents

Abstract

A surface treatment method for electrode terminals for secondary batteries and electrode terminals for secondary batteries surface-treated using the same are disclosed. According to one aspect of the present invention, a degreasing step of degreasing the conductive strip, an etching step of etching the conductive strip that has passed through the degreasing step, a chemical conversion film treatment step of subjecting the conductive strip that has undergone the etching step to a chemical conversion film, and a chemical conversion film treatment step A surface treatment method of a secondary battery electrode terminal including an organic film treatment step of treating a conductive strip with an organic film is provided.

Description

Surface treatment method of electrode terminal for secondary battery and surface treatment electrode terminal for secondary battery using the same

The present invention relates to a surface treatment method of an electrode terminal for a secondary battery and an electrode terminal for a secondary battery surface-treated using the same.

The present invention relates to a surface treatment method for an electrode terminal for a secondary battery.

Along with semiconductors and displays, the secondary battery industry is in the limelight as a key component of IT devices. In recent years, its use has increased for applications such as electric bicycles, hybrid vehicles (HEV), electric vehicles (EV), plug-in hybrid vehicles (PHEV), and energy storage devices (ESS) in which large-capacity batteries are used.

An electrode terminal (positive terminal and negative terminal), which is one of the parts of a general secondary battery, serves to electrically connect the current collector to the outside by being in contact with or connected to the distal end (ie, electrode tab) of the current collector. One side of these electrode terminals is located inside the unit cell case of the secondary battery, and the other side is located outside the unit cell case. In order to prevent the electrolyte inside the unit cell from leaking through the joint between the electrode terminal and the case, an insulating film is placed. It is attached in the middle of this electrode terminal.

These electrode terminals usually use the same material as the current collector, and are plated with a corrosion-resistant metal to prevent corrosion by external air and foreign substances. Specifically, the positive electrode terminal and the positive electrode current collector may be made of aluminum, and the negative electrode terminal and the negative electrode current collector may be made of copper. Since the electrode terminal made of aluminum or copper is easily oxidized and weak against corrosion, the surface thereof is coated with nickel. It is used by plating the back.

Republic of Korea Patent Registration No. 10-1213352 (2012.12.18. Notice)

The present invention provides a surface treatment method for secondary battery electrode terminals capable of improving the adhesion between the surface of the conductive strip and the film by treating the surface of the conductive strip with a chemical conversion film and an organic film, and a surface-treated electrode terminal for secondary batteries using the same is to do

According to one aspect of the present invention, a degreasing step of degreasing the conductive strip, an etching step of etching the conductive strip that has passed through the degreasing step, a chemical conversion film treatment step of subjecting the conductive strip that has undergone the etching step to a chemical conversion film, and a chemical conversion film treatment step A surface treatment method of a secondary battery electrode terminal including an organic film treatment step of treating a conductive strip with an organic film is provided.

In the conversion film treatment step, the conductive strip that has undergone the etching step may be subjected to a conversion film treatment using a coating agent containing chromium.

In the organic film treatment step, the conductive strip that has undergone the chemical conversion film treatment step may be film-treated using an organic film agent containing an amine-based compound.

The organic coating agent may include 92 to 94 parts by weight of water and 1 to 3 parts by weight of an amine-based compound.

The surface treatment method of the secondary battery electrode terminal may further include a water washing step of washing the surface of the conductive strip between at least one of the degreasing step, the etching step, the chemical conversion film treatment step, and the organic film treatment step.

The etching step may be performed by a soft etching process for forming fine irregularities on the conductive strip.

The method of treating the surface of the electrode terminal for a secondary battery may further include an unwinding step of unwinding the conductive strip provided in a state wound around the first reel unit from the first reel unit before the degreasing step.

The surface treatment method of the electrode terminal for a secondary battery includes a drying step of drying the conductive strip that has undergone the organic film treatment step after the organic film treatment step and a rewinding of winding and storing the conductive strip that has undergone the drying step on the second reel unit. ) step may be further included.

In addition, according to another aspect of the present invention, a secondary battery electrode terminal surface-treated using the surface treatment method of the secondary battery electrode terminal of claims 1 to 8 is provided.

According to the present invention, the adhesion between the surface of the conductive strip and the film can be improved by treating the surface of the conductive strip with a chemical conversion film and an organic film.

1 is a flowchart illustrating a surface treatment method of an electrode terminal for a secondary battery according to an embodiment of the present invention.
2 is a diagram showing a surface treatment apparatus for a secondary battery electrode terminal for performing a surface treatment method for an electrode terminal for a secondary battery according to an embodiment of the present invention.
3 is a view showing a secondary battery surface-treated using the surface treatment method of an electrode terminal for a secondary battery according to an embodiment of the present invention.
4 is a view showing adhesion between a secondary battery and a film surface-treated using a method for treating the surface of an electrode terminal for a secondary battery according to an embodiment of the present invention.
5 is a graph showing the adhesive strength of a secondary battery and a film surface-treated using the surface treatment method of an electrode terminal for a secondary battery according to an embodiment of the present invention.
6 is a diagram illustrating a case in which electrolyte leakage occurs between a case of a battery and an electrode terminal.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

In addition, coupling does not mean only the case of direct physical contact between each component in the contact relationship between each component, but another configuration intervenes between each component so that the component is in the other configuration. It should be used as a concept that encompasses even the case of contact with each other.

Hereinafter, an embodiment of the electrode terminal 100 for a secondary battery according to the present invention and surface-treated using the same will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals, and overlapping descriptions thereof will be omitted.

According to an embodiment of the present invention, a degreasing step (S120) of degreasing the conductive strip 110, an etching step (S130) of etching the conductive strip 110 having passed through the degreasing step (S120), and an etching step (S130). A chemical conversion film treatment step (S140) of chemical conversion film treatment of the rough conductive strip 110 and an organic film treatment step (S150) of organic film treatment of the conductive strip 110 that has undergone the chemical conversion film treatment step (S140). A surface treatment method of the electrode terminal 100 is disclosed.

The electrode terminal 100 for a secondary battery electrically connects between a battery and an electronic device, and a film 140 may be attached to prevent leakage of electrolyte between the case of the battery and the electrode terminal.

In this embodiment, the adhesive strength between the surface of the conductive strip 110 and the film 140 can be improved through the chemical conversion film treatment step (S140) and the organic film treatment step (S150), thereby preventing leakage of the electrolyte solution. You can (see Figure 6).

When charging and discharging of such a secondary battery is repeated, expansion may occur, resulting in defects in the battery pouch or leakage of the electrolyte.

Hereinafter, each step of the surface treatment method of the electrode terminal 100 for a secondary battery according to the present embodiment will be described with reference to FIGS. 1 to 5 .

As shown in FIG. 1, the present embodiment includes a delamination step (S120) of delaminating the conductive strip 110, an etching step (S130) of etching the conductive strip 110 that has passed through the delamination step (S120), and an etching step (S130). A chemical conversion film treatment step (S140) of subjecting the conductive strip 110 passed through (S130) to a chemical conversion film treatment (S140) and an organic film treatment step (S150) of performing an organic film treatment on the conductive strip 110 that passed through the conversion film treatment step (S140). Thus, the surface of the secondary battery electrode terminal 100 can be treated.

As shown in FIG. 2, this embodiment includes a first reel unit 210, a degreasing unit 220, an etching unit 230, a chemical conversion film processing unit 240, an organic film processing unit 250, water washing It may be performed by the electrode terminal surface treatment apparatus 200 including the unit 260 and the second reel unit 270 .

In addition, in this embodiment, the conductive strip 110 is unwound from the first reel unit 210 on which the conductive strip 110 is wound in a reel-to-reel manner, and the above-described stripping step (S120) and etching step (S130) ), the chemical conversion film treatment step (S140) and the organic film treatment step (S150) may be performed (S110), and the organic film treatment finished conductive strip 110 may be wound around the second reel unit 270 and stored. Yes (S170).

Therefore, as shown in FIG. 1 , prior to the degreasing step (S120), unwinding the conductive strip 110 provided in a state wound around the first reel unit 210 from the first reel unit 210 is performed. ) step (S110) may be performed, and after the organic film treatment step (S150), the conductive strip 110 that has passed through the organic film treatment step (S150) is wound around the second reel unit 270 and stored. Rewinding A (rewinding) step (S170) may be performed.

As shown in FIGS. 1 and 2, the degreasing step may be performed in the degreasing unit 220, and removes foreign matter attached to or contained on the surface of the conductive strip 110 provided from the first reel unit 210. tell the steps

More specifically, in the degreasing step (S120), an electrolytic degreasing method may be performed in which foreign substances adhered to or contained on the surface of the conductive strip 110 are removed by applying a voltage while passing an electrolyte solution through the conductive strip 110 .

Meanwhile, since the conductive strip 110 may be discolored if the degreasing step (S120) is performed beyond a predetermined time, it must be performed within a predetermined time.

Next, as shown in FIGS. 1 and 2 , the etching step (S130) may be performed in the etching unit 230, and the conductive strip 110 subjected to the stripping step (S120) is provided and the conductive strip 110 ) A step of removing unnecessary parts on the surface or processing the surface, which may be performed in a wet or dry manner.

More specifically, the etching step (S130) may be performed by a soft etching process for forming fine irregularities on the conductive strip 110, and the conductive strip 110 performed by the soft etching process has fine irregularities formed on the surface of the film. Adhesion may be improved by increasing the contact area with (140).

Next, as shown in FIGS. 1 and 2, the chemical conversion film processing step (S140) may be performed in the chemical conversion film processing unit 240, and the conductive strip 110 that has gone through the etching step (S130) is converted into a chemical conversion film. This is the processing step. More specifically, in the chemical conversion film treatment step (S140), the conductive strip 110 that has passed through the etching step (S130) may be subjected to a chemical conversion film treatment using a coating agent containing chromium.

The chemical conversion coating layer 120 may also generate a risk of permeation of the electrolyte solution in a high-temperature electrolyte environment.

Next, as shown in FIGS. 1 and 2, in the organic film treatment step (S150), the conductive strip 110 that has undergone the chemical conversion film treatment step (S140) is treated with an organic film using the organic film treatment unit 250. More specifically, in the organic film treatment step (S150), the conductive strip 110 that has undergone the chemical conversion film treatment step (S140) may be coated with an organic film agent containing an amine-based compound.

As shown in Table 1 below, the composition of the organic coating agent may be formed, the amine compound may include triethanolamine (2.2'.2"-Nitrilotriethanol), and the organic coating agent may contain 92 to 94 parts by weight of water and amine compound 1 to 3 parts by weight, and more specifically, 20,000 to 30,000 PPM of the amine-based compound may be included in the organic coating agent.

Substance name Alias (usual name) CAS number content(%) water dihydrogen oxide; Oksashidan 7732-18-5 / KE-35400 92~94 triethanolamine 2.2'.2"-Nitrilotriethanol 102-71-6 1 to 3 other additives 4 to 6

As shown in (a) of FIG. 3, when the film 140 is attached to the conductive strip 110 that has undergone the chemical conversion film treatment step (S140), as shown in (b) of FIG. 3, the organic film treatment step (S150) is also performed. Corrosion resistance is weaker than when the film 140 is attached to the rough conductive strip 110, and thus, the adhesive strength between the conductive strip 110 and the film 140 may be lowered.

As shown in (a) of FIG. 4, when the organic film treatment step (S150) is not performed, the chromium of the conversion film layer 120 may be oxidized, and the film 140 and the conductive strip 110 are formed by the oxide film. ) may be lowered, and as shown in (b) of FIG. 4, when the organic film treatment step (S150) is performed, the surface treatment of chrome of the conversion film layer 120 and the organic film layer 130 The compound may be stably bonded to improve the adhesive strength between the film 140 and the conductor.

Meanwhile, in the organic film treatment step (S150), the film may be subjected to electrolytic treatment so that the thickness of the film can be adjusted.

As shown in FIGS. 1 and 2, the water washing step (S200) is performed in at least one of the degreasing step (S120), the etching step (S130), the chemical conversion film treatment step (S140), and the organic film treatment step (S150). The surface of the conductive strip 110 may be cleaned using the water washing unit 260, and may be performed even after the organic film treatment step (S150) is performed.

Also, as shown in FIG. 1 , after the organic film treatment step ( S150 ), a drying step ( S160 ) of drying the conductive strip 110 that has undergone the organic film treatment step ( S150 ) may be performed.

Next, referring to FIGS. 1 to 5 , the surface-treated electrode terminal 100 for a secondary battery using the method for treating the surface of the electrode terminal 100 for a secondary battery according to the present embodiment will be described.

As shown in FIGS. 1 and 2 , the electrode terminal 100 for a secondary battery of this embodiment includes an unwinding step (S110), a degreasing step (S120), an etching step (S130), and a chemical conversion film treatment on the conductive strip 110. The surface treatment may be performed by performing step S140, organic film treatment step S150, rewinding step S170, and water washing step S200.

As shown in (b) of FIG. can be coated. The chemical conversion coating layer 120 and the organic coating layer 130 can protect the conductive strip 110 and at the same time improve adhesive strength with the film 140 attached to the outside of the electrode terminal.

The electrode terminal 100 for a secondary battery of this embodiment can be used by unwinding the conductive strip 110 from the second reel and cutting it to a predetermined length by a cutter, and after cutting, the film 140 can be attached.

Therefore, the electrode terminal 100 for a secondary battery of the present embodiment prevents oxidation of chromium of the chemical conversion film layer 120 and improves adhesion to the film 140, thereby preventing leakage of electrolyte solution of the battery.

On the other hand, as a result of comparing the adhesive strength of the electrode terminal 100 for a secondary battery according to this embodiment with the film 140, it was shown in FIG. 5.

As shown in Tables 2 and 3 below, the adhesive strength when the conductive strip 110 is nickel or copper and the adhesive strength when the conductive strip 110 is aluminum can be measured, and FIG. 5(a) shows the adhesive strength between the film 140 and the conductive strip 110 when the conductive strip 110 is nickel or copper, and FIG. 5(b) shows the film 140 when the conductive strip 110 is aluminum. ) and the conductive strip 110, respectively, it can be seen that this embodiment can maintain a higher adhesive strength than the comparative groups as time passes.

The above-described measurement of the adhesive strength of the electrode terminal 100 for a secondary battery with the film 140 can be performed in an environment of 10,000 PPM of moisture at an electrolyte of 85 ° C, and takes 7 days when the conductive strip 110 is made of nickel or copper. , The Example was found to have a higher adhesive strength than the comparative group by about 60% or more.

On the other hand, the electrode terminal 100 for a secondary battery of this embodiment may use a conductive strip 110 of 0.2 to 0.4 T (mm), and at this time, in the case of the organic film layer 130, it may be formed with a thickness of nano units. .

Although one embodiment of the present invention has been described above, those skilled in the art can add, change, delete, or add components within the scope not departing from the spirit of the present invention described in the claims. The present invention can be variously modified and changed by the like, and this will also be said to be included within the scope of the present invention.

100: electrode terminal for secondary battery
110: conductive strip
120: conversion film layer
130: organic film layer
140: film
200: electrode terminal surface treatment device
210: first reel unit
220: degreasing unit
230: etching unit
240: conversion coating processing unit
250: organic film treatment unit
260: water washing unit
270: second reel unit

Claims (9)

a degreasing step of degreasing the conductive strip;
an etching step of etching the conductive strip that has undergone the degreasing step;
a chemical conversion film treatment step of performing a chemical conversion film treatment on the conductive strip that has undergone the etching step; and
An organic film treatment step of treating the conductive strip that has undergone the chemical conversion film treatment step with an organic film,
In the chemical conversion film treatment step, the conductive strip subjected to the etching step is subjected to a chemical conversion film treatment using a coating agent containing chromium to improve corrosion resistance of the conductive strip,
In the organic film treatment step, the conductive strip subjected to the chemical conversion film treatment step is treated with a film using an organic film agent containing an amine compound to improve adhesive strength with a film attached to the conductive strip,
Prior to the degreasing step,
and an unwinding step of unwinding the conductive strip provided in a state wound around the first reel unit from the first reel unit.
After the organic film treatment step,
a drying step of drying the conductive strip that has undergone the organic film treatment step; and
Further comprising a rewinding step of winding and storing the conductive strip that has passed through the drying step around a second reel unit,
In the process of moving the conductive strip from the first unit to the second reel unit, the degreasing step, the etching step, the chemical conversion film treatment step, and the organic film treatment step are performed.
delete delete According to claim 1,
The organic coating agent comprises 92 to 94 parts by weight of water and 1 to 3 parts by weight of an amine compound, a surface treatment method for a secondary battery electrode terminal.
According to claim 1,
In at least one of the degreasing step, the etching step, the chemical conversion film treatment step, and the organic film treatment step,
Further comprising a water washing step of washing the surface of the conductive strip, the method of treating the surface of the electrode terminal for a secondary battery.
According to claim 1,
Wherein the etching step is performed as a soft etching process for forming fine irregularities on the conductive strip.
delete delete An electrode terminal for a secondary battery surface-treated using the method of treating the surface of an electrode terminal for a secondary battery according to any one of claims 1 and 4 to 6.

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