High-purity micro-rod beta-Na0.33V2O5 particles 2-5 mm in width and 3-10 mm in length are prepared by the chemical switch method. Electrochemical characterization demonstrates that micro-rod beta-Na0.33V2O5 as a cathode material for lithium ion batteries provides high discharge capacity, good rate-capability, and cyclic stability. It delivers high discharge capacities of 297, 245, 220, and 178 mAh g (1) at current densities of 0.1, 0.2, 0.5, and 1 C-rate, respectively. The capacity fading rate is less than 1% per cycle, with high volumetric discharge capacities (504 mAh cm (3) at 0.1C and 301 mAh cm (3) at 1 C). Scanning electron microscopy images of the micro-rods during cycling indicate that they have excellent crystal structural reversibility in the voltage range of 1.5-4.0 V. These superior electrochemical properties are attributed to the tunneled crystal structure and internal pores formed by crystal defects in the microrods. (C) 2016 Elsevier Ltd. All rights reserved.