Abstract: A positive electrode active material for a lithium secondary battery includes a lithium cobalt complex oxide containing an alkali earth metal and a transition metal in a predetermined mixture ratio. A method of preparing the positive electrode active material includes mixing a lithium salt, a transition metal precursor, and an alkali earth metal salt to form a mixture, and performing at least one thermal treatment on the mixture. A positive electrode for a lithium secondary battery includes the positive electrode active material, and a lithium secondary battery includes the positive electrode.

Abstract: Provided is a pouch-type rechargeable battery. A rechargeable battery according to an exemplary embodiment of the present invention includes: an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; a case receiving the electrode assembly; an electrolyte solution injection member positioned at one side of the case and forming an injection hole; and a sealing member covering and sealing the injection hole.

Abstract: A positive electrode active material for a lithium secondary battery includes a lithium cobalt complex oxide containing an alkali earth metal and a transition metal in a predetermined mixture ratio. A method of preparing the positive electrode active material includes mixing a lithium salt, a transition metal precursor, and an alkali earth metal salt to form a mixture, and performing at least one thermal treatment on the mixture. A positive electrode for a lithium secondary battery includes the positive electrode active material, and a lithium secondary battery includes the positive electrode.

Abstract: Provided is a pouch-type rechargeable battery. A rechargeable battery according to an exemplary embodiment of the present invention includes: an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; a case receiving the electrode assembly; an electrolyte solution injection member positioned at one side of the case and forming an injection hole; and a sealing member covering and sealing the injection hole.

Abstract: Embodiments of the present invention are directed to electrode assemblies and secondary batteries using the same. The secondary battery includes an electrode assembly including a positive electrode having a positive active material, a negative electrode including a negative active material, and a separator between the positive and negative electrodes. The positive active material includes a lithium composite oxide represented by LiCO1?x?yMgxTiyO2 where 0.0056?x?0.0089, and 0.0029?y?0.0045. The electrode assembly and the lithium secondary battery including the same show good discharge efficiency even with increases in C-rate, and substantially prevent reductions in battery capacity resulting from battery deterioration, thereby improving battery lifespan.