Lg Chem, Ltd

Jong Heon Seol

Sang Hoon Choy

Ye Lin Kim

Je Young Kim

Jung Keun Yoo

Dong Hyun Cho

Kyung Yeon Kang

Ki Yeon Jo

Ji Hee Woo

Min Hee Lee

Seul Ki Kim

Jae Woong Kim

Sun Kyu Kim

Dong Kyu Kim

Hyung Suk Cho

Hee Soo Na

Chan Sub Lee

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 &#x3bc;m to 0.5 &#x3bc;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.

Positive electrode having improved pore structure in positive electrode active material layer

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.

Conductive material dispersed liquid and secondary battery manufactured using the same

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/mand 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:&#x2212;&#x2264;10 log&#x2264;&#x2212;0.6&#x2003;&#x2003;[Equation 1]

Conductive material dispersed liquid and lithium secondary battery manufactured using the same

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&#xb0; to 18&#xb0; 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.

Conductive material dispersed liquid and lithium secondary battery manufactured using same

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.

Conductive material for secondary battery, and secondary battery containing same

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.

Electrode for lithium secondary battery and lithium secondary battery including the same

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.

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Daejeon, South Korea

Jong Heon Seol