Search NASA⌕ Search

DOE OSTI · 1355287

Materials Data on V2FeSe4 by Materials Project

Abstract

FeV2Se4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. V+2.50+ is bonded to six Se2- atoms to form distorted VSe6 octahedra that share corners with six equivalent FeSe6 octahedra, edges with six equivalent VSe6 octahedra, and a faceface with one FeSe6 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of V–Se bond distances ranging from 2.44–2.72 Å. Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with twelve equivalent VSe6 octahedra, edges with two equivalent FeSe6 octahedra, and faces with two equivalent VSe6 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are two shorter (2.46 Å) and four longer (2.55 Å) Fe–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent V+2.50+ and two equivalent Fe3+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent V+2.50+ and one Fe3+ atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-23. Materials Data on V2FeSe4 by Materials Project. https://doi.org/10.17188/1355287

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗