Positive-electrode active material for elevation of output and lithium secondary battery including the same

摘要

A lithium secondary battery having improved output characteristics is provided. A high voltage mixed positive electrode active material has an even profile without causing a rapid voltage drop over the entire SOC area by improving a rapid voltage drop phenomenon occurring due to the difference between the operation voltages of mixed lithium transition metal oxides, and improves output characteristics at a low voltage. The lithium secondary battery includes the mixed positive electrode active material. In particular, the lithium secondary battery can sufficiently satisfy the required conditions such as output characteristics, capacity, stability, and the like, when it is used as a power source of a midsize or large device such as an electric vehicle.

主权项

1. A lithium secondary battery comprising:
a mixed positive electrode active material comprising a lithium manganese oxide of a layered structure represented by [Chemical Formula 1] shown below and a metal oxide having an olivine structure represented by [Chemical Formula 2] shown below and charged at a voltage of 4.6 V or higher based on a positive electrode potential, wherein the mixed positive electrode active material includes the metal oxide having the olivine structure in an amount of 10-40 wt %, and wherein the metal oxide having the olivine structure in the mixed positive electrode active material is coated with a conductive material;
0.5Li2MnO3-0.5Li(Mn0.33Ni0.33Co0.33)O2  [Chemical Formula 1]LiFePO4.  [Chemical Formula2]