Synthesis of Na_1.25V₃O₈ nanobelts with excellent long-term stability for rechargeable lithium-ion batteries

Sodium vanadium oxide (Na_1.25V₃O₈) nanobelts have been successfully prepared by a facile sol-gel route with subsequent calcination. The morphologies and the crystallinity of the as-prepared Na_1.25V₃O₈ nanobelts can be easily controlled by the calcination temperatures. As cathode materials for lithium ion batteries, the Na_1.25V₃O₈ nanobelts synthesized at 400 C exhibit a relatively high specific discharge capacity of 225 mA h g^-1 and excellent stability at 100 mA g^-1. The nanobelt-structured electrode can retain 94% of the initial capacity even after 450 cycles at the current density of 200 mA g^-1. The good electrochemical performance is attributed to their nanosized thickness and good crystallinity. The superior electrochemical performance demonstrates the Na _1.25V₃O₈ nanobelts are promising cathode materials for secondary lithium batteries.