Designing new lithium-excess cathode materials from percolation theory: Nanohighways in Li_xNi_{2-4 x /3}Sb_x/3O₂

Increasing lithium content is shown to be a successful strategy for designing new cathode materials. In layered Li_xNi_2-4x/3Sb_x/3O₂ (x = 1.00-1.15), lithium excess improves both discharge capacity and capacity retention at 1C. Structural studies reveal a complex nanostructure pattern of Li-Sb and Ni-Sb ordering where the interface between these domains forms the correct local configuration for good lithium mobility. The <1 nm Li-Sb stripe domains and their interfaces thereby effectively act as nanohighways for lithium diffusion.