Designing New Lithium-Excess Cathode Materials from Percolation Theory: Nanohighways in Li[subscript x]N[subscript 2–4x/3]Sb[subscript x/3O[subscript 2]

Abstract

Increasing lithium content is shown to be a successful strategy for designing new cathode materials. In layered Li[subscript x]N[subscript 2–4x/3]Sb[subscript x/3O[subscript 2] (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.