γ′-V 2 O 5 Polymorph: A Genuine Zn Intercalation Material for Nonaqueous Rechargeable Batteries

International audienceThe electrochemical properties of the puckered layered '-V 2 O 5 polymorph as cathode material in a non-aqueous Zn-metal cell using acetonitrile-Zn(CF 3 SO 3) 2 electrolyte are investigated here for the first time. The typical galvanostatic profile in the 2 V-0.3 V vs. Zn 2+ /Zn voltage range shows a sloping discharge curve involving a capacity of 130 mAh g-1 at C/20 in one single step centered at 0.9 V vs. Zn 2+ /Zn. The structural response of '-V 2 O 5 during the discharge-charge cycle is investigated by ex-situ X-ray diffraction (XRD) and Raman spectroscopy. Up to 0.41 Zn mol-1 can be accommodated between the '-V 2 O 5 layers, inducing only a moderate interlaye