Development of a high-rate-capable O3-structured ‘layered’ Na transition metal oxide by tuning the cation–oxygen bond covalency

Abstract

By developing a high-rate-capable O3-structured Na(Li_0.05Ni_0.3Si_0.05Ti_0.45Cu_0.1Mg_0.05)O₂-based cathode material for Na-ion batteries, wherein partial substitution of more electronegative Si⁴⁺ for Ti⁴⁺ in the transition metal layer has weakened-cum-lengthened the Na–O bond, enlarged the ‘inter-slab’ spacing and, thus, enhanced the Na-transport kinetics, a design criterion has been laid-out in the above context.