Influence of Lattice Parameter Differences on the Electrochemical Performance of the 5 V Spinel LiMn[sub 1.5−y]Ni[sub 0.5−z]M[sub y+z]O[sub 4] (M=Li, Mg, Fe, Co, and Zn)

Cation substituted spinel cathodes exhibit superior capacity retention and rate capability in the 5 V region compared to the unsubstituted cathode. For example, , , and exhibit capacity fades of in 50 cycles with at rate compared to 8% fade and for . Also, retains 92% of its capacity on going from to the 4C rate compared to 82% for . The superior performances of these cathodes are attributed to the smaller lattice parameter differences among the three cubic phases formed during the charge-discharge process.