Scalable and template-free synthesis of nanostructured Na_1.08V₆O₁₅ as high-performance cathode material for lithium-ion batteries

Developing high-capacity cathode material with feasibility and scalability is still challenging for lithium-ion batteries (LIBs). In this study, a high-capacity ternary sodium vanadate compound, nanostructured NaV₆O₁₅, was template-free synthesized through sol-gel process with high producing efficiency. The as-prepared sample was systematically post-treated at different temperature and the post-annealing temperature was found to determine the cycling stability and capacity of NaV₆O₁₅. The well-crystallized one exhibited good electrochemical performance with a high specific capacity of 302 mAh g^-1 when cycled at current density of 0.03 mA g^-1. Its relatively long-term cycling stability was characterized by the cell performance under the current density of 1 A g^-1, delivering a reversible capacity of 118 mAh g^-1 after 300 cycles with 79% capacity retention and nearly 100% coulombic efficiency: all demonstrating its significant promise of proposed strategy for large-scale synthesis of NaV₆O₁₅ as cathode with high-capacity and high energy density for LIBs.