A distinctive strategy of Sb doped quaternary oxide cathodes materials toward energy storage of electric equipment for sodium-ion batteries

Abstract

The poor cycle stability and rate capability for sodium-ion batteries is largely due to electrochemical irreversibility and sluggish mobility of Na+ in the cathode materials. Herein, a new strategy of introducing Sb ions into the ternary oxide NiMnTi-based layer-structured cathode material is designed. Reversible phase transition in this cathode NMTSb0.03 restraint the rapid capacity decay issued from intense volume variation, exhibiting a reversible capacity of 147.8 mAh g−1 and retaining 103.5 mAh g−1 over 200 cycles at 1C. The enough space after Sb substitution allows the effective accommodation of Na+ intercalation and deintercalation, affording a specific capacity of 90 mAh g−1 at 8C. The improvement is attributed to the enhanced Na+ diffusion kinetics with the meliorative equilibrium conductance and the higher cohesive energy after Sb doping. Considering its simple preparation and scale-up capability, the O3-type NaNi0.5Mn0.3Ti0.2O2 with Sb5+may find extensive applications in designing electrode for sodium-ion batteries.