| 摘要 |
Disclosed are a cathode active material and a secondary battery including the same. Herein, the cathode active material includes (a) a first lithium-containing metal composite oxide and (b) a second lithium-containing metal composite oxide coated on an entire particle surface of the first lithium-containing metal composite oxide, the second lithium-containing metal composite oxide having a higher resistance and a lower potential vs. lithium potential (Li/Li″ 1) than the first lithium-containing metal composite oxide. In the disclosed cathode active material, an entire surface of a first lithium-containing metal composite oxide is coated with a second lithium-containing metal composite oxide having a high resistance value and a low potential vs. lithium potential. Therefore, during an internal short of a secondary battery, it is possible to slow down the moving rate of a large amount of lithium ions and electrons from an anode to a cathode, and thus to prevent heat generation caused by the occurrence of temporary over-current. Also, it is possible to increase the temperature where a cathode active material is decomposed and gas is generated, and to improve thermal stability by inhibiting side reactions of the cathode active material and electrolyte. |
