KR20190011945A - Analysis method of boron contents in anode materials of lithium secondary battery - Google Patents

Abstract

The present invention provides a method for accurately and rapidly performing quantitative-analysis of boron contents in an anode material of a lithium secondary battery. An existing method for performing a quantitative-analysis of boron of the anode material by heating and acidizing the anode material in a vial or heating and acidizing the anode material after adding mannitol into the anode material has inconvenience in which an accurate amount of boron contents is not be acquired. To solve this, according to the method of the present invention, boron of the anode material can be accurately and rapidly quantitative-analyzed as the anode material is acidized in an airtight plastic container by using a closed system preprocessing system.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for analyzing a boron content in an anode material of a lithium secondary battery,

The present invention relates to a method for quantitative analysis of boron present in an anode material of a lithium secondary battery.

The lithium secondary battery comprises a cathode material that provides lithium ions when charged, an anode material that stores lithium ions, a separator that prevents internal shorts, and an electrolyte that provides space and environment for lithium ions to move. The cathode material and the anode material are respectively coated on both sides of the separator, and lithium ions move through charging and discharging through the separator.

The cathode material of the lithium secondary battery is a source of lithium, which is a main raw material that releases and absorbs lithium from the crystal lattice of the cathode material during charging and discharging of the battery to store and discharge electric energy in the battery. Boron is used as a dopant material of the cathode material to improve the performance of the anode material, thereby improving the cycle characteristics of the battery. Boron is also used as an additive in electrolytic solutions composed of organic solvents and the like. Therefore, it is necessary to analyze the boron content in order to analyze the raw materials in the cathode material and the electrolytic solution. Further, boron in the negative electrode material is necessary for the analysis of the boron content reduced in the negative electrode after the cycle degeneration of the battery.

The difficulty faced in the analysis of boron is that it should suppress the volatilization loss of boron. (BCl ₃ , bp: 12.5 ° C) or boron trifluoride (BF ₃ , bp: -) when hydrochloric acid, hydrofluoric acid (HF) or the like is used on the hot plate on the hot plate during decomposition of the anode re- Lt; RTI ID = 0.0 > 101 C). ≪ / RTI > A decomposition method using mannitol (C ₆ H ₁₄ O ₆ ) is known to suppress the volatilization loss of boron. It has been reported that when mannitol is added together with the decomposed anode sample, mannitol binds to boron to form a stable complex, thereby suppressing the volatilization loss of boron even in the presence of hydrofluoric acid, hydrochloric acid, and the like. In addition, due to the difficulty of decomposing the sample, studies have been reported on decomposing an anode material sample using a microwave digestion system (MDS). However, the MDS method has the advantage that the sample can be decomposed quickly and effectively as compared with the acid decomposition under the atmospheric pressure on the hot plate, but it has a disadvantage that a microwave decomposition apparatus is necessarily required. In addition, since boron is also present in the glass as a main reaction vessel, when F-based substances are present in the case of decomposition using an acid or mannitol in a glass vessel (vial), the boron component Can be measured together and the results of the boron content analysis can be confused. Therefore, it is possible to accurately measure the boron content without contamination by using an appropriate analysis tool according to the composition of the sample.

The present inventors have recognized this problem of the prior art and explored a method for analyzing the boron content in an anode material using an inductively coupled plasma spectrophotometer (ICP-OES). In general, various element components contained in the negative electrode material or reduced after the cycle test of the battery are analyzed by treatment with hydrochloric acid, nitric acid, hydrofluoric acid, or the like in a glass container. In the case of boron, since the main component is glass, , The boron content in the glass was also eluted due to the damage of the glass container due to the formation of HF when the anode material sample containing the F series binder was placed in the glass container and the acid treatment was performed.

In the present invention, a method of easily and rapidly measuring the content of boron in the anode material without causing the above problems has been studied. As a result, it is possible to easily measure the boron content in the anode material in a short time by preparing a closed system pretreatment system using a conical tube made of a plastic material, It turned out.

Accordingly, in the present invention, a new method for quantitatively analyzing boron in an anode material, which can prevent the disadvantages that the boron content analysis value is inaccurate when the content of boron in the anode material is analyzed using a glass container and an acid, . ≪ / RTI >

An object of the present invention is to provide a method for accurately and rapidly quantitatively analyzing the amount of boron in an anode material of a lithium secondary battery.

To achieve the above object, the present invention provides, in one embodiment,

Weighing the negative electrode re-sample into a closed plastic container;

Adding acid and hydrogen peroxide to the sample and closing the cap of the container;

Heating the solution in the vessel with a water bath to dissolve the sample;

Diluting the solution with ultrapure water; And

And analyzing the boron content in the diluent. The method for analyzing the content of boron in an anode material of a lithium secondary battery is provided.

In one embodiment, the closed plastic container is a PET conical tube, for example a PET Corning tube.

In one embodiment, the acid is hydrochloric acid, hydrofluoric acid, nitric acid or a mixture of two or more thereof.

In one embodiment, the hydrogen peroxide can be used at a level of 1/10 of the acid.

In one embodiment, the ratio of the anode material to the acid, for example, hydrochloric acid, is 1: 5 to 1:15 by weight.

In one embodiment, the water bath is performed on a hot plate set at 100 to 200 ° C.

In one embodiment, the water bath is performed for less than 3 hours.

In one embodiment, ICP-OES is used to measure the boron content in the negative electrode material.

In one embodiment, the relative standard deviation (RSD) of the quantitative analysis results of boron by the ICP-OES is 7% Or less.

The quantitative analysis method of the present invention can obtain an accurate quantitative analysis result of boron contained in an anode material of a lithium secondary battery by using a closed system pretreatment system using a closed plastic tube.

Hereinafter, the present invention will be described in more detail.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor can properly define the concept of the term to describe its invention in the best possible way And should be construed in accordance with the principles and meanings and concepts consistent with the technical idea of the present invention.

In one embodiment, a method for quantitative analysis of boron in an anode material of a lithium secondary battery comprises:

Weighing the negative electrode re-sample into a closed plastic container;

Adding acid and hydrogen peroxide to the sample and closing the cap of the container;

Heating the solution in the vessel with a water bath to dissolve the sample;

Diluting the solution with ultrapure water; And

And analyzing the boron content in the diluent.

Quantitative analysis of boron in an anode material of the lithium secondary battery The present invention relates to a method for detecting boron contained in an anode material or reduced after a cycle test of a battery.

The methods of quantitative analysis of boron that have been used in the past are methods by an acid decomposition method under an atmospheric pressure on a hot plate or an open system in which mannitol is added to form a complex of mannitol and boron and pretreatment. However, in these methods, HF is formed when an anode material sample containing an F series binder is placed in a glass container and the boron component in the glass is eluted due to the damage of the glass container due to HF, so that the boron content analysis result is obtained accurately .

However, according to the quantitative analysis method of the present invention, by applying the anode material to a closed system pretreatment system using a plastic material conic tube instead of an open system pretreatment system using a glass container, The amount of boron present in the anode material can be quantitatively analyzed accurately and quickly.

In one embodiment, the conical tube is, for example, a PET Corning tube.

In one embodiment, the acid is the acid is hydrochloric acid, hydrofluoric acid, nitric acid or a mixture of two or more thereof, preferably hydrochloric acid.

In one embodiment, the hydrogen peroxide can be used at a level of 1/10 of the acid.

In one embodiment, the use ratio of the negative electrode material and the acid is 1: 5 to 1:15, preferably 1:10 to 1:12 by weight.

In one embodiment, the water bath is performed on a hot plate set at 100 to 200 캜, preferably at 100 to 150 캜.

In one embodiment, the water bath is performed for 3 hours or less, preferably 1 to 3 hours.

In one embodiment, ICP-OES is used to measure the boron content in the negative electrode material.

In one embodiment, the relative standard deviation (RSD) of the quantitative analysis results of boron by the ICP-OES is 7% Or less.

The quantitative analysis method according to the present invention can accurately and quickly measure the boron content in the anode material which is inaccurate by the method using the open system pretreatment system using the conventional glass vessel. According to the quantitative analysis method of the present invention, the content of boron in the anode material of the lithium secondary battery can be easily analyzed within a short time.

Hereinafter, the present invention will be described in more detail with reference to Examples. It will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples in accordance with the gist of the present invention, It will be self-evident.

<Examples>

One. Anode material  Pretreatment method

1) According to the prior art Open system  Preprocessing system ( Comparative Example  1 to 3)

(1) Comparative Example 1

In this Comparative Example 1, an open system pretreatment system using a glass container and mannitol was used as a pretreatment method for an anode material according to a conventional method.

(1) About 0.1 g of the negative electrode re-sample was accurately measured in the vial.

(2) About 0.5 g of mannitol (5 times of the anode material sample) was added to the vial to prevent the volatilization of boron in the sample of the anode material in the vial.

(3) 1 mL of hydrochloric acid (36 to 38% (v / v)) was added to the vial, and the mixture was heated on a hot plate set at 70 DEG C, .

(4) When the anode material sample dissolved, 10 mL of ultrapure water was added to dilute the solution.

(5) After cooling the solution to room temperature, the content of elements contained in the anode material sample was measured using ICP-OES. The analytical wavelengths of boron were 249.577 nm and 249.772 nm.

(2) Comparative Example 2

The procedure of Comparative Example 1 was repeated except that mannitol was not used and the setting temperature of the hot plate was changed to 100 캜.

(3) Comparative Example 3

Comparative Example 1 was repeated except that mannitol was not used and the setting temperature of the hot plate was changed to 130 캜.

2) According to the present invention Closed system  Preprocessing system ( Example )

In this embodiment, the closed-system pretreatment system according to the present invention is used in a pretreatment method of an anode material.

(1) About 0.1 g of an anode re-sample was accurately measured in a PET Corning tube.

(2) 1 mL of hydrochloric acid (36 to 38% (v / v)) was placed in the Corning tube containing the negative electrode material sample.

(3) Five drops of hydrogen peroxide (100 μl; 1 drop = 20 μl) were placed in a Corning tube containing the sample, and the tube was closed by closing the tube.

(4) The tube was heated on a hot plate set at 130 DEG C for 2 hours with a water bath to dissolve the sample, and then 10 mL of ultrapure water was added to dilute the solution.

(5) After cooling the solution to room temperature, the content of elements contained in the anode material sample was measured using ICP-OES. The analytical wavelengths of boron were 249.577 nm and 249.772 nm.

2. Analysis data (ICP)

The contents of the elements in the anode material samples analyzed according to Comparative Examples 1 to 3 and Examples are shown in Table 1 below. In addition, the contents of the elements in the anode material samples analyzed after heating the cathode material samples at 100 ° C. and 130 ° C. according to the prior art, respectively, after acid treatment (open system) are also shown in Table 1 below.

Pre-treatment type Content (mg / kg) Ni Co Mn Fe B Zr One 70 ° C Mannitol-vial (Comparative Example 1) 29 3 3 5 389 38 2 100 DEG C heat-vial (Comparative Example 2) 24 2 2 4 466 35 3 130 ° C heat-vial (Comparative Example 3) 35 7 3 3 671 35 4
130 ℃ water bath heating - Corning tube
(Example) 37 3 2 2 141 37

In the case of pretreating the anode material samples in the vial according to Comparative Examples 1 to 3 (corresponding to pretreatment types 1 to 3 in Table 1), although the boron component in the anode material sample was well volatilized by heating and acid treatment, (389 mg / kg → 466 mg / kg → 671 mg / kg) as measured by the temperature (70 ° C. → 100 ° C. → 130 ° C.). This result is expected to be due to the elution of boron from the vial, and therefore, it is difficult to know the exact content of boron in the anode material by pretreatment of the anode material through heating and acid treatment.

On the other hand, in the case of the pretreatment in which the volatilization of boron was prevented by using a closed system pre-treatment system (corning tube) according to the embodiment of the present invention and contamination was prevented (corresponding to pretreatment type 4 in Table 1), the analyzed boron content Was 141 mg / kg, it can be seen that boron in the anode material was accurately analyzed without any external influences. This conclusion is similar to that of pretreatment type 3 in the analysis of Ni, Co, Mn, Fe and Zr according to pretreatment type 4 in Table 1, while only the analysis value of boron was 141 mg / kg (pretreatment type 4) kg (pretreatment type 3).

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It will be appreciated that other embodiments are possible. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (8)

Weighing the negative electrode re-sample into a closed plastic container;
Adding acid and hydrogen peroxide to the sample and closing the cap of the container;
Heating the solution in the vessel with a water bath to dissolve the sample;
Diluting the solution with ultrapure water; And
And analyzing the boron content in the diluent. &Lt; Desc / Clms Page number 19 &gt; The method of claim 1, wherein the acid is hydrochloric acid, hydrofluoric acid, nitric acid or a mixture of two or more thereof. The method for analyzing the content of boron in an anode material for a lithium secondary battery according to claim 1, wherein the ratio of the anode material to the acid is 1: 5 to 1:15 by weight. The method according to claim 1, wherein the water bath is performed on a hot plate set at 100-200 占 폚. The method of claim 1, wherein the water bath is performed for 3 hours or less. The method of claim 1, wherein the closed plastic container is a PET conical tube. The method of claim 6, wherein the conical tube is a PET Corning tube. A method for analyzing the content of boron in an anode material of a lithium secondary battery. The method of claim 1, wherein an inductively coupled plasma spectrophotometer (ICP-OES) is used to measure the boron content in the anode material.