| abstract |
50 cycles of charge / discharge when comparing the capacity after the 52nd cycle when cycled between 2.5V and 4.7V against Li / Li + at 30 ° C with the capacity after the second cycle. A positive electrode for a lithium ion electrochemical cell having a capacity retention greater than about 95% after cycling is provided. Compositions useful in the positive electrode provided are: Li 1 + x (Ni a Mn b Co c ) 1-x O 2 , where 0.05 ≦ x ≦ 0.10, a + b + c = 1, 0.6 ≦ b / a ≦ 1.1, c / (a + b) <0.25, a, b, and c are all greater than 0]. The process for producing these positive electrodes involves firing the composition at 850 ° C. to 925 ° C. [Selection] Figure 1 |