Positive electrode additive for lithium secondary battery and positive electrode for lithium secondary battery comprising same

A method for making a positive electrode additive for a lithium secondary battery comprising:

• mixing an amount of a lithium oxide, an amount of a nickel oxide, and an amount of a nickel fluoride to form an additive mixture;
• applying pressure to the additive mixture in a pelletizer under conditions sufficient to form additive mixture pellets;
• and
• heat-treating the additive mixture pellets in a furnace by increasing the temperature at a heating rate of 2° C./min to 10° C./min to a temperature of 500° C. to 1000° C., and heating for a total time ranging from 5-30 hours to form the positive electrode additive;
• wherein the amount of lithium oxide, the amount of nickel oxide, and the amount of nickel fluoride are added to the additive mixture in a molar ratio to provide a positive electrode additive of Formula 1:
• wherein x is in the range of 0.95<x<1.00, y is in the range of 1.90<y<2.00, z is in the range of 0.00<z<0.10.