01786nas a2200205   4500000000100000008004100001260003000042100001800072700001800090700001800108700001800126700002200144700001600166245011400182856004300296300001600339490000600355520120500361020001401566       2015                            d  bAmerican Chemical Society1 aAnanta Sarkar1 aSudeep Sarkar1 aTanmay Sarkar1 aParveen Kumar1 aMridula Bharadwaj1 aSagar Mitra00aRechargeable Sodium-Ion Battery: High-Capacity Ammonium Vanadate Cathode with Enhanced Stability at High Rate  uhttps://doi.org/10.1021/acsami.5b03210  a17044-170530 v73 aSodium-ion battery (NIB) cathode performance based on ammonium vanadate is demonstrated here as having high capacity, long cycle life and good rate capability. The simple preparation process and morphology study enable us to explore this electrode as suitable NIB cathode. Furthermore, density functional theory (DFT) calculation is envisioned for the NH4V4O10 cathode, and three possible sodium arrangements in the structure are depicted for the first time. Relevant NIB-related properties such as average voltage, lattice constants, and atomic coordinates have been derived, and the estimated values are in good agreement with the current experimental values. A screening study shows ammonium vanadate electrodes prepared on carbon coat onto Al-current collector exhibits a better electrochemical performance toward sodium, with a sustained reversible capacity and outstanding rate capability. With the current cathode with nanobelt morphology, a reversible capacity of 190 mAh g–1 is attained at a charging rate of 200 mA g–1, and a stable capacity of above 120 mAh g–1 is retained for an extended 50 cycles tested at 1000 mA g–1 without the addition of any expensive electrolyte additive.  a1944-8244