Synthesis of Na(1.25)V(3)O(8) nanobelts with excellent long-term stability for rechargeable lithium-ion batteries.

Sodium vanadium oxide (Na1.25V3O8) nanobelts have been successfully prepared by a facile sol-gel route with subsequent calcination. The morphologies and the crystallinity of the as-prepared Na1.25V3O8 nanobelts can be easily controlled by the calcination temperatures. As cathode materials for lithium ion batteries, the Na1.25V3O8 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 Na1.25V3O8 nanobelts are promising cathode materials for secondary lithium batteries.