Engineering Papers⌕ Search

DOE OSTI · 1205308

Materials Data on Na2Sb4O7 by Materials Project

Abstract

Na2Sb4O7 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.55 Å. There are two inequivalent Sb3+ sites. In the first Sb3+ site, Sb3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 2.01–2.21 Å. In the second Sb3+ site, Sb3+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 1.99–2.38 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Na1+ and two equivalent Sb3+ atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 tetrahedra. In the second O2- site, O2- is bonded to two equivalent Na1+ and two Sb3+ atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 tetrahedra. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three Sb3+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Na1+ and two equivalent Sb3+ atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 tetrahedra.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-18. Materials Data on Na2Sb4O7 by Materials Project. https://doi.org/10.17188/1205308

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↗