Ultra-thin (<10nm diameter) VO2(B) nanowires have been synthesised, characterised structurally and morphologically and their lithium intercalation electrochemistry investigated. The wires exist in bundles and exhibit significant preferred orientation. They have a capacity to intercalate lithium of 265 mAh g(-1) (Li0.82VO2(B)) at a rate of 10 mA g(-1) compared with thicker wires of 50-100 nm diameter which exhibit a capacity of 200 mAh g(-1) at the same rate. The load curves, structure and morphology remain stable on cycling. (C) 2007 Elsevier B.V. All rights reserved.