阅读说明：本技术 预测电极浆料的工艺性和选择电极粘合剂的方法 (Method for predicting manufacturability of electrode slurry and selecting electrode binder ) 是由 梁辉秀 曺炯锡 薛琮宪 崔相勳 于 2018-09-27 设计创作，主要内容包括：根据本公开内容的方法允许通过确定电极浆料的粘度的变化的简单方法来预测电极浆料的相稳定性。因此,在将电极浆料引入到制造电极的工艺中之前,仅选择具有高的相稳定性的电极浆料。然后,将所选择的电极浆料引入到该工艺中,以提供改善的工艺效率的效果。(The method according to the present disclosure allows predicting the phase stability of the electrode paste by a simple method of determining the change in viscosity of the electrode paste. Therefore, only electrode pastes having high phase stability are selected before the electrode pastes are introduced into the process of manufacturing electrodes. The selected electrode paste is then introduced into the process to provide the effect of improved process efficiency.)

1. A method of selecting an electrode paste, the method comprising: determining a particle size distribution of composite particles in a mixed sample including a plurality of electrode active material particles, a polymer resin for a binder, and a solvent; and comparing the particle size distribution with a particle size distribution of the electrode active material particles to judge phase stability of the electrode slurry.

2. The method of selecting an electrode slurry according to claim 1, wherein the mixed sample includes an electrode active material, a polymer resin for a binder, and a solvent, and the electrode active material is a carbonaceous material, and the solvent is water.

3. The method of selecting an electrode slurry according to claim 1, wherein the mixed sample includes an electrode active material, a polymer resin for a binder, and a solvent, and the binder is used in an amount of 0.05-0.3 parts by weight based on 1 part by weight of the electrode active material, and the solvent is used in an amount of 8-15 parts by weight based on 1 part by weight of the electrode active material.

4. The method of selecting an electrode slurry according to claim 1, wherein the polymer resin for the binder is a particulate polymer.

5. The method of selecting an electrode slurry according to claim 1, wherein the composite particles are formed from aggregation of solids content contained in the electrode slurry.

6. The method of selecting an electrode slurry of claim 1, wherein the D of the composite particles in the mixed sample₅₀With anode active material particles D₅₀A comparison is made.

7. The method of selecting an electrode slurry of claim 6, further comprising comparing D of the composite particles in the sample₁₀And/or D₉₀And D of the anode active material particles₁₀And/or D₉₀A comparison is made.

8. The method of selecting an electrode paste according to claim 6, wherein the binder introduced into the mixed sample is selected as a binder for preparing an electrode paste when the condition of formula 1 is satisfied:

[ formula 1]

D of the composite particles₅₀<D of the negative active material particles₅₀×A，

Wherein A is 0.001-10.0.

9. The method of selecting an electrode paste according to claim 6, wherein when the condition of formula 2 and/or the condition of formula 3 is satisfied in addition to the condition of formula 1, the binder introduced to the mixed sample is selected as a binder for preparing an electrode paste:

[ formula 2]

D of the composite particles₁₀<D of the negative active material particles₁₀×A

[ formula 3]

D of the composite particles₉₀<D of the negative active material particles₉₀×A

In formulas 2 and 3, each a independently represents 0.001 to 10.0.

10. The method of selecting an electrode paste according to claim 6, wherein when the condition of formula 2 and the condition of formula 3 are satisfied in addition to the condition of formula 1, the binder introduced to the mixed sample is selected as a binder for preparing an electrode paste:

[ formula 2]

D of the composite particles₁₀<D of the negative active material particles₁₀×A

[ formula 3]

D of the composite particles₉₀<D of the negative active material particles₉₀×A

In formulas 2 and 3, each a independently represents 1 to 3.

11. The method of selecting an electrode paste according to claim 6, wherein in formulas 1 to 3, A ranges from 0.001 to 10.0, and is determined in consideration of at least one selected from the group consisting of an introduced material, a paste concentration, a processing time, a transfer distance of the paste, a temperature condition of the paste storage location, a humidity condition of the paste storage location, and a paste storage time.

Technical Field

The present application claims priority from korean patent application No. 10-2017-0126526, filed in korea at 28.9.2017, the disclosure of which is incorporated herein by reference. The present disclosure relates to a method of predicting process compatibility, e.g., changes in viscosity, of an electrode slurry and selecting an appropriate type and content of binder in the manufacture of an electrode for an electrochemical device.

Background

As the technical development and demand for mobile devices increase, the demand for secondary batteries as an energy source is increasing. Among these secondary batteries, lithium secondary batteries having high energy density and operating voltage, long cycle life, and low self-discharge rate have been commercialized and widely used.

Such a lithium secondary battery has developed a model capable of realizing a high voltage and a high capacity corresponding to the demand of consumers. In order to achieve high capacity, four main elements of the lithium secondary battery, i.e., a positive electrode material, a negative electrode material, a separator, and an electrolyte, need to be optimized in a limited space.

Specifically, the anode includes an anode mixture layer formed on at least one surface of a current collector, and the anode mixture layer is prepared by coating and drying an anode slurry including an anode active material, a binder polymer, a conductive material, and a dispersion medium.

The binder polymer serves to stably fix the electrode active material in the electrode and prevent particles from falling off. However, the binder polymer tends to increase the viscosity of the electrode slurry or to gel with the lapse of time. When the slurry is gelled or its viscosity is excessively increased, filter clogging and viscosity increase occur during the manufacture and transportation of the negative electrode slurry. This may result in discarding of the anode slurry or coating defects. Therefore, a method of preparing an anode slurry for a secondary battery that undergoes small changes over time is required.

Disclosure of Invention

Technical problem

The present disclosure is directed to providing a method of predicting process compatibility, such as changes in viscosity and phase stability, of an electrode slurry and selecting an appropriate electrode slurry composition and binder composition and content in the manufacture of an electrode for an electrochemical device. These and other objects and advantages of the present disclosure will be understood from the following detailed description, and will become more apparent from the exemplary embodiments of the present disclosure. Further, it will be readily understood that the objects and advantages of the present disclosure may be realized by the means as set forth in the appended claims and combinations thereof.

Technical scheme

The present disclosure is directed to solving the problems of the related art. In one aspect of the present disclosure, a method of selecting an electrode paste capable of judging phase stability of the electrode paste is provided. According to a first embodiment of the present disclosure, there is provided a method of selecting an electrode paste, the method comprising: determining a particle size distribution of composite particles in a mixed sample including a plurality of electrode active material particles, a polymer resin for a binder, and a solvent; and comparing the particle size distribution with a particle size distribution of electrode active material particles to judge phase stability of the electrode slurry.

According to a second embodiment of the present disclosure, there is provided the method of selecting an electrode slurry as defined in the first embodiment, wherein the mixed sample includes an electrode active material, a polymer resin for a binder, and a solvent, and the electrode active material is a carbonaceous material and the solvent is water.

According to a third embodiment of the present disclosure, there is provided the method of selecting an electrode slurry as defined in the first or second embodiment, wherein the mixed sample includes an electrode active material, a polymer resin for a binder, and a solvent, and the binder may be used in an amount of 0.05 to 0.3 parts by weight based on 1 part by weight of the electrode active material, and the solvent may be used in an amount of 8 to 15 parts by weight based on 1 part by weight of the electrode active material.

According to a fourth embodiment of the present disclosure, there is provided the method of selecting an electrode paste as defined in any one of the first to third embodiments, wherein the polymer resin for the binder is a particulate polymer.

According to a fifth embodiment of the present disclosure, there is provided a method of selecting an electrode paste as defined in any one of the first to fourth embodiments, wherein the composite particles are formed by aggregation of solid contents contained in the electrode paste.

According to a sixth embodiment of the present disclosure, there is provided the method of selecting an electrode slurry as defined in any one of the first to fifth embodiments, wherein D of the composite particles in the mixed sample is₅₀With anode active material particles D₅₀A comparison is made.

According to a seventh embodiment of the present disclosure, there is provided the method of selecting an electrode paste as defined in any one of the first to sixth embodiments, further comprising subjecting D of the composite particles in the sample to₁₀And/or D₉₀With anode active material particles D₁₀And/or D₉₀A comparison is made.

According to an eighth embodiment of the present disclosure, there is provided the method of selecting an electrode paste as defined in any one of the first to seventh embodiments, wherein the binder introduced to the mixed sample is selected as the binder for preparing the electrode paste when the condition of formula 1 is satisfied:

[ formula 1]

D of the composite particles₅₀<D of the negative active material particles₅₀×A，

Wherein A is 0.001-10.0.

According to a ninth embodiment of the present disclosure, there is provided the method of selecting an electrode paste as defined in any one of the first to eighth embodiments, wherein when the condition of formula 2 and/or the condition of formula 3 is satisfied in addition to the condition of formula 1, the binder introduced to the mixed sample is selected as the binder for preparing the electrode paste:

[ formula 2]

D of the composite particles₁₀<D of the negative active material particles₁₀×A，

[ formula 3]

D of the composite particles₉₀<D of the negative active material particles₉₀×A，

In formulas 2 and 3, each a independently represents 0.001 to 10.0.

According to a tenth embodiment of the present disclosure, there is provided the method of selecting an electrode paste as defined in any one of the first to ninth embodiments, wherein when the condition of formula 2 and the condition of formula 3 are satisfied in addition to the condition of formula 1, the binder introduced to the mixed sample is selected as the binder for preparing the electrode paste:

[ formula 2]

D of the composite particles₁₀<D of the negative active material particles₁₀×A，

[ formula 3]

D of the composite particles₉₀<D of the negative active material particles₉₀×A，

In formulas 2 and 3, each a independently represents 1 to 3.

According to an eleventh embodiment of the present disclosure, there is provided the method of selecting an electrode paste as defined in any one of the first to tenth embodiments, wherein in formulas 1 to 3, a ranges from 0.001 to 10.0, and a is determined in consideration of at least one selected from the group consisting of an introduced material, a slurry concentration, a processing time, a transport distance of the slurry, a temperature condition of a slurry storage location, a humidity condition of a slurry storage place, and a slurry storage time.

Advantageous effects

According to the present disclosure, the phase stability of the electrode paste may be predicted by a simple method of determining the change in viscosity of the electrode paste. Therefore, only electrode pastes having high phase stability are selected before the electrode pastes are introduced into the process of manufacturing electrodes. The selected electrode paste is then introduced into the process to provide the effect of improved process efficiency.