Abstract: A lithium secondary battery includes a positive electrode including a lithium manganese-based first positive electrode active material having a spinel structure and a lithium nickel-manganese-cobalt-based second positive active material and a negative electrode including artificial graphite having a specific surface area (BET) of 0.1-1.2 m2/g and natural graphite having a greater specific surface area than the artificial graphite. The lithium manganese-based first positive electrode active material includes a lithium manganese oxide and a coating layer positioned on the surface of the lithium manganese oxide and including one or more elements selected from the group consisting of Al, Ti, W, B, F, P, Mg, Ni, Co, Fe, Cr, V, Cu, Ca, Zn, Zr, Nb, Mo, Sr, Sb, Bi, Si, and S.

Abstract: A bridge structure for combining a first electrode assembly stacked with a second electrode assembly includes a first welding part to which a first electrode tab of the first electrode assembly is bonded; a second welding part to which a second electrode tab of the second electrode assembly is bonded; and a connecting part which connects the first welding part and the second welding part to each other. The first and second welding parts are offset from one another in a diagonal direction that is oblique to the stacking direction of the first and second electrode assemblies. The connecting part extends in the diagonal direction to connect the first and second welding parts to each other.

Abstract: A lithium secondary battery includes a positive electrode including a lithium manganese-based first positive electrode active material having a spinel structure doped and coated and a lithium nickel-manganese-cobalt-based second positive active material, a negative electrode including artificial graphite having a specific surface area (BET) of 0.1-1.2 m2/g and at least one selected from the group consisting of soft carbon and natural graphite which have a greater specific surface area than the artificial graphite, a separator interposed between the positive electrode and the negative electrode, and an electrolyte.

Abstract: A lithium secondary battery includes a positive electrode including a lithium manganese-based first positive electrode active material having a spinel structure doped and coated and a lithium nickel-manganese-cobalt-based second positive active material, a negative electrode including artificial graphite having a specific surface area (BET) of 0.1-1.2 m2/g and at least one selected from the group consisting of soft carbon and natural graphite which have a greater specific surface area than the artificial graphite, a separator interposed between the positive electrode and the negative electrode, and an electrolyte.

Abstract: The present invention relates to a compound which can be used as a material for a hole injection layer or a hole transporting layer of organic light emitting diodes (OLEDs) or electroluminescent elements. The compound is synthesized into a conductive polymer using liquid polymer ions, and this conductive polymer can be used as a material for a hole injection layer or a hole transporting layer of an organic light emitting diode. The compound is advantageous in that a hole injection layer formed using the compound has more excellent performance and can be maintained over a longer lifespan than a hole injection layer formed using conventional compounds.