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.