Abstract: A method that allows prediction of phase stability of an electrode slurry through a simple method of determining a change in viscosity of the electrode slurry. Therefore, only the electrode slurry having high phase stability is selected before electrode slurry is introduced to a process for manufacturing an electrode. Then, the selected electrode slurry is introduced to the process to provide an improved effect of process efficiency.

Abstract: A method for evaluating phase stability of an electrode mixture slurry, including the steps of: (S1) introducing the electrode mixture slurry to a rheometer; (S2) applying a first shear rate to the electrode mixture slurry; (S3) applying a second shear rate after applying the first shear rate to the electrode mixture slurry, wherein the second shear rate is higher than the first shear rate; (S4) applying a third shear rate after applying the second shear rate to the electrode mixture slurry, wherein the third shear rate is lower than the second shear rate; and (S5) comparing the shear viscosity at the first shear rate with the shear viscosity at the third shear rate. An apparatus for evaluating phase stability of the electrode mixture slurry is also provided.

Abstract: A positive electrode for a lithium secondary battery includes a positive electrode current collector; a lower positive electrode active material layer disposed on at least one surface of the positive electrode current collector; and an upper positive electrode active material layer disposed on the lower positive electrode active material layer, wherein the lower positive electrode active material layer includes 90% or more of a sphere-type carbonaceous conductive material as a conductive material, the upper positive electrode active material layer includes 90% or more of a needle-type carbonaceous conductive material as a conductive material, and the content of the conductive material contained in the lower positive electrode active material layer is larger than the content of the conductive material contained in the upper positive electrode active material layer.

Abstract: Provided herein are a positive electrode for a secondary battery and a secondary battery including the same. The positive electrode includes a positive electrode active material layer including a positive electrode active material, a conductive material, and a dispersant, wherein the conductive material includes bundle-type carbon nanotubes, units of which have an average strand diameter of 15 nm or less, and the positive electrode active material layer has a packing density of 3.0 g/cc or more, and has an average pore diameter of 0.1 ?m to 0.5 ?m at the packing density when a pore size distribution is measured by mercury intrusion porosimetry, and thus may exhibit excellent electrolyte wetting properties. As a result, when the positive electrode is applied to a battery, wetting time of the positive electrode is shortened, and an area of the positive electrode that is not filled with an electrolyte is reduced, resulting in enhanced battery performance.

Abstract: The present invention provides a conductive material dispersed liquid including a conductive material which includes bundle-type carbon nanotubes; a dispersant which includes a hydrogenated nitrile-based rubber; and a dispersion medium, where a complex modulus (|G*| @ 1 Hz) is in a range of 20 to 500 Pa when measured by a rheometer at a frequency of 1 Hz, and a secondary battery manufactured using the same. The conductive material dispersed liquid has a controlled complex modulus to exhibit excellent dispersibility and powder resistance characteristics, and as a result, can greatly improve the output characteristics of batteries.

Abstract: The present invention provides: a conductive material dispersed liquid containing a conductive material, a dispersant, and a dispersion medium, wherein the conductive material comprises bundle-type carbon nanotubes having a bulk density in a range of 10-50 kg/m3 and a conductivity satisfying the conditions of Equation 1 below, thereby exhibiting excellent dispersibility and conductivity; and a lithium secondary battery, which is manufactured using the conductive material dispersed liquid and thus can exhibit excellent battery functions, especially, excellent output characteristics at low temperatures: ?X?10 log R??0.6X??[Equation 1] (in Equation 1 above, X is a bulk density of the carbon nanotubes, and R is a powder resistance of the carbon nanotubes under a pressure of 10 to 65 MPa.).

Abstract: A negative electrode including: a current collector; a first negative electrode active material layer positioned on at least one surface of the current collector for a negative electrode and containing a first carbonaceous active material; and a second negative electrode active material layer positioned on a surface of the first negative electrode active material layer and containing a silicon-based active material and carbon nanotubes. A lithium secondary battery including the negative electrode is also disclosed.

Abstract: The present invention provides a conductive material dispersed liquid, including: a conductive material which includes bundle-type carbon nanotubes; a dispersant; a dispersion medium, where a phase angle is in a range of 3° to 18° when measured by a rheometer at a frequency of 1 Hz; and a lithium secondary battery manufactured using the conductive material dispersed liquid. The conductive material dispersed liquid has high solid-like properties, and thus allows the formation of an electrode active material layer having a uniform thickness with no concern for collapse or occurrence of cracks during manufacture of an electrode, and thereby can improve the performance characteristics, particularly capacity characteristics, of a battery.

Abstract: A method for evaluating phase stability of an electrode mixture slurry, including the steps of: (S1) introducing the electrode mixture slurry to a rheometer; (S2) applying a first shear rate to the electrode mixture slurry; (S3) applying a second shear rate after applying the first shear rate to the electrode mixture slurry, wherein the second shear rate is higher than the first shear rate; (S4) applying a third shear rate after applying the second shear rate to the electrode mixture slurry, wherein the third shear rate is lower than the second shear rate; and (S5) comparing the shear viscosity at the first shear rate with the shear viscosity at the third shear rate. An apparatus for evaluating phase stability of the electrode mixture slurry is also provided.

Abstract: A method that allows prediction of phase stability of an electrode slurry through a simple method of determining a change in viscosity of the electrode slurry. Therefore, only the electrode slurry having high phase stability is selected before electrode slurry is introduced to a process for manufacturing an electrode. Then, the selected electrode slurry is introduced to the process to provide an improved effect of process efficiency.

Abstract: The present invention provides a conductive material for a secondary battery, and a secondary battery containing the same, the conductive material comprising carbon nanotubes, having a secondary structure in which carbon nanotube units having a diameter of 20-150 nm are entangled, having a ratio of true density to bulk density (TD/BD) of 30-120, having a metal content of 50 ppm or less, and having both excellent dispersibility and high purity, thereby being capable of improving, by increasing the conductivity within an electrode, battery performance, particularly, battery performance at room temperature and low temperature when applied to a battery.

Abstract: Disclosed is a positive electrode for a lithium secondary battery which uses a positive electrode active material containing secondary particles with a relatively weak particle strength to improve the adhesion between a positive electrode mixture layer and a current collector, and the positive electrode includes a positive electrode current collector; a primer coating layer including a first polymer binder and a first conductive material, having surface roughness (Ra) of 85 nm to 300 nm and formed on at least one surface of the positive electrode current collector; and a positive electrode mixture layer formed on an upper surface of the primer coating layer and including a positive electrode active material containing secondary particles with a compressive breaking strength of 1 to 15 MPa, a second polymer binder and a second conductive material.

Abstract: An electrode for a lithium secondary battery includes a current collector, primer layer formed on a side of the current collector and includes a first conductive agent, a first binder and a first dispersant. Further, an active material layer is formed on a side of the primer layer disposed opposite to the current collector and includes an active material. Additionally, the lithium secondary battery includes a positive electrode, a negative electrode or both, a separator disposed between the positive electrode and the negative electrode and an electrolyte. The structural stability and adhesion of the electrode is improved, a ratio of a binder in the active material layer is reduced and the internal resistance is reduced.

Abstract: Provided are a positive electrode material mixture, in which, the positive electrode material mixture includes a positive electrode active material, a conductive agent, and a binder, wherein the conductive agent includes a particulate conductive agent, a fibrous conductive agent, and a plate-shaped conductive agent, and the binder includes a crystalline binder having a weight-average molecular weight (Mw) of 500,000 g/mol to 900,000 g/mol and an amorphous binder having a weight-average molecular weight (Mw) of 200,000 g/mol to 400,000 g/mol.

Abstract: A positive electrode for a lithium secondary battery includes a positive electrode current collector; a lower positive electrode active material layer disposed on at least one surface of the positive electrode current collector; and an upper positive electrode active material layer disposed on the lower positive electrode active material layer, wherein the lower positive electrode active material layer includes 90% or more of a sphere-type carbonaceous conductive material as a conductive material, the upper positive electrode active material layer includes 90% or more of a needle-type carbonaceous conductive material as a conductive material, and the content of the conductive material contained in the lower positive electrode active material layer is larger than the content of the conductive material contained in the upper positive electrode active material layer.

Abstract: The present invention provides a conductive material dispersed liquid including a conductive material which includes bundle-type carbon nanotubes; a dispersant which includes a hydrogenated nitrile-based rubber; and a dispersion medium, where a complex modulus (|G*| @ 1 Hz) is in a range of 20 to 500 Pa when measured by a rheometer at a frequency of 1 Hz, and a secondary battery manufactured using the same. The conductive material dispersed liquid has a controlled complex modulus to exhibit excellent dispersibility and powder resistance characteristics, and as a result, can greatly improve the output characteristics of batteries.

Abstract: Provided herein are a positive electrode for a secondary battery and a secondary battery including the same. The positive electrode includes a positive electrode active material layer including a positive electrode active material, a conductive material, and a dispersant, wherein the conductive material includes bundle-type carbon nanotubes, units of which have an average strand diameter of 15 nm or less, and the positive electrode active material layer has a packing density of 3.0 g/cc or more, and has an average pore diameter of 0.1 ?m to 0.5 ?m at the packing density when a pore size distribution is measured by mercury intrusion porosimetry, and thus may exhibit excellent electrolyte wetting properties. As a result, when the positive electrode is applied to a battery, wetting time of the positive electrode is shortened, and an area of the positive electrode that is not filled with an electrolyte is reduced, resulting in enhanced battery performance.

Abstract: The present invention provides: a conductive material dispersed liquid containing a conductive material, a dispersant, and a dispersion medium, wherein the conductive material comprises bundle-type carbon nanotubes having a bulk density in a range of 10-50 kg/m3 and a conductivity satisfying the conditions of Equation 1 below, thereby exhibiting excellent dispersibility and conductivity; and a lithium secondary battery, which is manufactured using the conductive material dispersed liquid and thus can exhibit excellent battery functions, especially, excellent output characteristics at low temperatures: ?X?10 log R??0.6X??[Equation 1] (in Equation 1 above, X is a bulk density of the carbon nanotubes, and R is a powder resistance of the carbon nanotubes under a pressure of 10 to 65 MPa.).

Abstract: The present invention provides a conductive material for a secondary battery, and a secondary battery containing the same, the conductive material comprising carbon nanotubes, having a secondary structure in which carbon nanotube units having a diameter of 20-150 nm are entangled, having a ratio of true density to bulk density (TD/BD) of 30-120, having a metal content of 50 ppm or less, and having both excellent dispersibility and high purity, thereby being capable of improving, by increasing the conductivity within an electrode, battery performance, particularly, battery performance at room temperature and low temperature when applied to a battery.

Abstract: The present invention provides a conductive material dispersed liquid, including: a conductive material which includes bundle-type carbon nanotubes; a dispersant; a dispersion medium, where a phase angle is in a range of 3° to 18° when measured by a rheometer at a frequency of 1 Hz; and a lithium secondary battery manufactured using the conductive material dispersed liquid. The conductive material dispersed liquid has high solid-like properties, and thus allows the formation of an electrode active material layer having a uniform thickness with no concern for collapse or occurrence of cracks during manufacture of an electrode, and thereby can improve the performance characteristics, particularly capacity characteristics, of a battery.