Methods of measuring electrode density and electrode porosity
View Patent ↗Provided is a method for non-destructively measuring an electrode density and an electrode porosity of an electrode active material coated on an electrode base material using X-ray diffraction. According to the methods of the present invention, a value of I peak in parallel direction /I peak in perpendicular direction of the electrode active material is obtained by X-ray diffraction and an electrode density and an electrode porosity are calculated according to previously obtained correlations between the electrode density and I peak in parallel direction /I peak in perpendicular direction and between the electrode porosity and I peak in parallel direction /I peak in perpendicular direction .
1. A method of non-destructively measuring an electrode density of an electrode active material coated on an electrode base material, the method comprising:
obtaining non-destructively an I peak in parallel direction /I peak in perpendicular direction value of an electrode active material coated on an electrode base material by X-ray diffraction; and
calculating an electrode density according to a previously obtained correlation between the electrode density and the I peak in parallel direction /I peak in perpendicular direction value of the same type of electrode active material,
wherein the electrode active material is a crystalline material,
wherein I peak in parallel direction is an intensity peak when the crystal planes for the electrode active material are arranged parallel to a base plane of the electrode,
wherein I peak in perpendicular direction is an intensity peak when the crystal planes for the electrode active material are arranged perpendicular to a base plane of the electrode,
wherein the correlation between the electrode density and the I peak in parallel direction /I peak in perpendicular direction value is obtained in advance by obtaining electrode densities of at least three or more electrodes including a same electrode active material according to Equation 2, measuring an I peak in parallel direction /I peak in perpendicular direction value of the electrode active material of the corresponding electrode by X-ray diffraction, and analyzing a correlation between the three or more values of electrode density according to Equation 2 and I peak in parallel direction /I peak in perpendicular direction value of the electrode active material:
D=M /( S×H ) <Equation 2>,
where D represents an electrode density, S is an electrode area, M is a mass of an electrode active material excluding an electrode base material in an electrode, and H represents a thickness of the electrode active material excluding the electrode base material in the electrode.
2. The method of claim 1 , wherein the electrode active material comprises a crystalline carbon-based active material.
3. The method of claim 1 , wherein the I peak in parallel direction /I peak in perpendicular direction of the electrode active material is I 002 /I 100 , I 002 /I 110 , I 004 /I 100 , I 004 /I 110 , I 006 /I 100 , or I 006 /I 110 .
4. The method of claim 1 , wherein in the correlation, the electrode density and the I peak in parallel direction /I peak in perpendicular direction of the electrode active material have a linear relationship.
5. The method of claim 4 , wherein in the correlation, a coefficient of determination (R 2 ) of the electrode density is in a range of 0.6 to 1.0.
6. A method of non-destructively measuring an electrode porosity of an electrode active material coated on an electrode base material, the method comprising:
obtaining non-destructively an I peak in parallel direction /I peak in perpendicular direction value of an electrode active material coated on an electrode base material by X-ray diffraction; and
calculating an electrode porosity according to a previously obtained correlation between the electrode porosity and the I peak in parallel direction /I peak in perpendicular direction value of the same type of electrode active material,
wherein the electrode active material is a crystalline material,
wherein I peak in parallel direction is an intensity peak when the crystal planes for the electrode active material are arranged parallel to a base plane of the electrode,
wherein I peak in perpendicular direction is an intensity peak when the crystal planes for the electrode active material are arranged perpendicular to a base plane of the electrode,
wherein the correlation between the electrode porosity and I peak in parallel direction /I peak in perpendicular direction value of the electrode active material is obtained in advance by obtaining electrode porosities of at least three or more electrodes including a same electrode active material according to Equation 3 and measuring an I peak in parallel direction /I peak in perpendicular direction value of the electrode active material of the corresponding electrode by X-ray diffraction, and analyzing a correlation between the electrode porosity obtained according to Equation 3 and the I peak in parallel direction /I peak in perpendicular direction value of the electrode active material:
P=[ 1−( D/T )]×100 <Equation 3>,
where P represents an electrode porosity, D represents an electrode density, and T represents a true density of an electrode active material excluding an electrode base material in an electrode.
7. The method of claim 6 , wherein the electrode active material comprises a crystalline carbon-based active material.
8. The method of claim 6 , wherein the I peak in parallel direction /I peak in perpendicular direction of the electrode active material is I 002 /I 100 , I 002 /I 110 , I 004 /I 100 , I 004 /I 110 , I 006 /I 100 , or I 006 /I 110 .
9. The method of claim 6 , wherein in the correlation, the electrode porosity and the I peak in parallel direction /I peak in perpendicular direction of the electrode active material have a linear relationship.
10. The method of claim 6 , wherein in the correlation, a coefficient of determination (R 2 ) of the electrode porosity is in a range of 0.6 to 1.0.