Sodium-Ion Intercalation in Bilayered V2O5 Modified Aerogel: Thermodynamic Characteristics of NaxV2O5 (0 ≤ x ≤ 4, and beyond)

Tuesday, 3 October 2017: 18:00
Maryland A (Gaylord National Resort and Convention Center)
W. H. Smyrl and F. Guillaume (University of Minnesota)
Sodium-ion batteries are candidates to replace lithium-ion analogs for energy storage, because of sustainability advantages. The technologies are similar, but the lithium system is much more advanced after two decades of development. A recent review on Na systems is available [Yabuuchi, et al. 2014], which documents the renewed interest for sodium after several years of intermittent research attention. The present study is for vanadium pentoxide modified-aerogel (V2O5/m-ARG) as an electrode material to host Na ion insertion and release. We have discovered that the capacity for sodium to be more than 4 moles of sodium per mole of V2O5, with a flat voltage plateau for 1= x = 4. This corresponds to a specific capacity of about 560 mAh/(g host) for x=4. The Equilibrium Potential vs Composition of Na+ ions was measured with the Galvanostatic Intermittent Titration Technique (GITT). The experimental specific energy is about 1600 WH/kg of the host. Further, the intercalation thermodynamics of Na+ ions has near-ideal behavior. The high specific capacity and the high specific energy makes the host an attractive cathode material for Na-ion systems.