β-V(2)O(5) as Magnesium Intercalation Cathode

[Image: see text] Magnesium batteries have attracted great attention as an alternative to Li-ion batteries but still suffer from limited choice of positive electrode materials. V(2)O(5) exhibits high theoretical capacities, but previous studies have been mostly limited to α-V(2)O(5). Herein, we report on the β-V(2)O(5) polymorph as a Mg intercalation electrode. The structural changes associated with the Mg(2+) (de-) intercalation were analyzed by a combination of several characterization techniques: in situ high resolution X-ray diffraction, scanning transmission electron microscopy, electron energy-loss spectroscopy, and X-ray absorption spectroscopy. The reversible capacity reached 361 mAh g(–1), the highest value found at room temperature for V(2)O(5) polymorphs.