TY - JOUR
T1 - Proton and Oxide Ion Conductivity in Palmierite Oxides
AU - Fop, Sacha
AU - Dawson, James A.
AU - Tawse, Dylan
AU - Skellern, Matthew Graham
AU - Skakle, Janet
AU - McLaughlin, Abbie
N1 - Open Access via the ACS Agreement
PY - 2022/9/27
Y1 - 2022/9/27
N2 - Solid proton and oxide ion conductors have key applications in several hydrogen-based and energy-related technologies. Here, we report on the discovery of significant proton and oxide ion conductivity in palmierite oxides A3V2O8 (A = Sr, Ba), which crystallize with a framework of isolated tetrahedral VO4 units. We show that these systems present prevalent ionic conduction, with a large protonic component under humidified air (tH ∼ 0.6–0.8) and high protonic mobility. In particular, the proton conductivity of Sr3V2O8 is 1.0 × 10–4 S cm–1 at 600 °C, competitive with the best proton conductors constituted by isolated tetrahedral units. Simulations show that the three-dimensional ionic transport is vacancy-driven and facilitated by rotational motion of the VO4 units, which can stabilize oxygen defects via formation of V2O7 dimers. Our findings demonstrate that palmierite oxides are a new promising class of ionic conductors where stabilization of parallel vacancy and interstitial defects can enable high ionic conductivity.
AB - Solid proton and oxide ion conductors have key applications in several hydrogen-based and energy-related technologies. Here, we report on the discovery of significant proton and oxide ion conductivity in palmierite oxides A3V2O8 (A = Sr, Ba), which crystallize with a framework of isolated tetrahedral VO4 units. We show that these systems present prevalent ionic conduction, with a large protonic component under humidified air (tH ∼ 0.6–0.8) and high protonic mobility. In particular, the proton conductivity of Sr3V2O8 is 1.0 × 10–4 S cm–1 at 600 °C, competitive with the best proton conductors constituted by isolated tetrahedral units. Simulations show that the three-dimensional ionic transport is vacancy-driven and facilitated by rotational motion of the VO4 units, which can stabilize oxygen defects via formation of V2O7 dimers. Our findings demonstrate that palmierite oxides are a new promising class of ionic conductors where stabilization of parallel vacancy and interstitial defects can enable high ionic conductivity.
U2 - 10.26434/chemrxiv-2022-58mlf
DO - 10.26434/chemrxiv-2022-58mlf
M3 - Article
C2 - 36193291
SN - 0897-4756
VL - 34
SP - 8190
EP - 8197
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 18
ER -