Abstract: A method for preparing a cathode active material for a lithium secondary battery is provided. The preparing method includes: adding a phosphorus compound to a transition metal oxide dispersion liquid to prepare a coating liquid; drying the coating liquid to prepare a powder including phosphorus oxide coated on the surface of the transition metal oxide; and dry-mixing the powder coated with the phosphorus oxide with a lithium intercalation compound, and then firing the mixture to form a solid solution compound of L1-M1-M2-P—O (where M1 is a transition metal derived from transition metal oxide, and M2 is a metal derived from lithium intercalation compound) on the surface of the lithium intercalation compound. The method for preparing a cathode active material for a lithium secondary battery simplifies the conventional preparing process to save process cost, and it provides comparable electrochemical characteristics to a cathode active material obtained from a wet process.

Abstract: Provided are a cathode active material for a lithium secondary battery and a lithium secondary battery including the same. The cathode active material includes a lithium composite oxide represented by the following Chemical Formula 1. Li[LizA]O2 A={M11-x-y(M10.78Mn0.22)x}M2y??[Chemical Formula 1] In Chemical Formula, M1 and M2 are independently one or more selected from a transition element, a rare earth element, or a combination thereof, M1 and M2 are elements that are different from each other, ?0.05?z?0.1, 0.8?x+y?1.8, and 0.05?y?0.35, and Ni has an oxidation number of 2.01 to 2.4.

Abstract: Disclosed is a method for preparing a cathode active material for a lithium secondary battery, and the preparing method includes: adding a phosphorus compound to a transition metal oxide dispersion liquid to prepare a coating liquid; drying the coating liquid to prepare a powder including phosphorus oxide coated on the surface of the transition metal oxide; and dry-mixing the powder coated with the phosphorus oxide with a lithium intercalation compound, and then firing the mixture to form a solid solution compound of Li-M1-M2-P—O (where M1 is a transition metal derived from transition metal oxide, and M2 is a metal derived from lithium intercalation compound) on the surface of the lithium intercalation compound. The method for preparing a cathode active material for a lithium secondary battery simplifies the conventional preparing process to save process cost, and it provides comparable electrochemical characteristics to a cathode active material obtained from a wet process.

Abstract: A battery case for enclosing and hermetically sealing a battery body which generates current. The case includes a first polyethylene terephthalate layer, which is an innermost layer with respect to a battery body, which is adhered to another part of the same layer when sealing the battery body, a polymer layer on the first polyethylene terephthalate layer, a second polyethylene terephthalate layer on the polymer layer, and a polypropylene layer, which is an outermost layer with respect to the battery body, on the second polyethylene terephthalate layer. Therefore, short circuits generated during adhesion between edges of upper and lower portions of the case can be prevented, improving the case sealing process. Also, the deterioration of battery performance, due to a micro short circuit occurring during the sealing of the case, can be avoided. Further, the case sealing process can be safely performed, irrespective of conditions of thermal fusion such as temperature, pressure, and time.