| abstract |
Positive electrodes (2) including a lithium nickel cobalt oxide are disclosed. The lithium nickel cobalt metal oxides have the general formula LixNiyCozMnO2, where M is selected from the group consisting of aluminum, titanium, tungsten, chromium, molybdenum, magnesium, tantalum, silicon, and combinations thereof, x is between about 0 and about 1 and can be varied within this range by electrochemical insertion and extraction, the sum of y+z+n is about 1, n ranges between above 0 to about 0.25, y and z are both greater than 0, and the ratio of z/y ranges from above 0 to about 1/3. Also disclosed are composite positive electrodes including the above-described lithium nickel cobalt metal oxides together with a lithium manganese metal oxide of the formula LixMn2-rM1rO4, where r is a value between 0 and 1 and M1 is chromium, titanium, tungsten, nickel, cobalt, iron, tin, zinc, zirconium, silicon, or a combination thereof. |