Search NASA⌕ Search

DOE OSTI · 1286001

Materials Data on Na3Ca3Zr2Si4(O5F)3 by Materials Project

Abstract

Na3Ca3Zr2Si4(O5F)3 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to four O2- and one F1- atom. There are a spread of Na–O bond distances ranging from 2.32–2.62 Å. The Na–F bond length is 2.24 Å. In the second Na1+ site, Na1+ is bonded in a 5-coordinate geometry to four O2- and one F1- atom. There are a spread of Na–O bond distances ranging from 2.33–2.62 Å. The Na–F bond length is 2.28 Å. In the third Na1+ site, Na1+ is bonded in a 7-coordinate geometry to four O2- and three F1- atoms. There are a spread of Na–O bond distances ranging from 2.39–2.76 Å. There are a spread of Na–F bond distances ranging from 2.31–2.93 Å. There are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Ca–O bond distances ranging from 2.14–2.45 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.27–2.80 Å. In the third Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to six O2- and one F1- atom. There are a spread of Ca–O bond distances ranging from 2.17–2.82 Å. The Ca–F bond length is 2.70 Å. There are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six O2- atoms to form distorted ZrO6 pentagonal pyramids that share a cornercorner with one ZrO7 pentagonal bipyramid, a cornercorner with one SiO4 tetrahedra, and an edgeedge with one ZrO6 pentagonal pyramid. There are a spread of Zr–O bond distances ranging from 1.98–2.31 Å. In the second Zr4+ site, Zr4+ is bonded to seven O2- atoms to form distorted ZrO7 pentagonal bipyramids that share a cornercorner with one ZrO6 pentagonal pyramid and an edgeedge with one ZrO7 pentagonal bipyramid. There are a spread of Zr–O bond distances ranging from 1.95–2.49 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to two O2- and one F1- atom. Both Si–O bond lengths are 1.63 Å. The Si–F bond length is 1.69 Å. In the second Si4+ site, Si4+ is bonded to three O2- and two F1- atoms to form edge-sharing SiO3F2 trigonal bipyramids. There are a spread of Si–O bond distances ranging from 1.64–1.88 Å. There is one shorter (1.65 Å) and one longer (1.76 Å) Si–F bond length. In the third Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.62 Å) and two longer (1.66 Å) Si–O bond length. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one ZrO6 pentagonal pyramid and an edgeedge with one SiO3F2 trigonal bipyramid. There are a spread of Si–O bond distances ranging from 1.61–1.72 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+, one Zr4+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two Ca2+, one Zr4+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two Na1+, one Ca2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Na1+, one Ca2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ca2+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Na1+, one Ca2+, and one Zr4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Zr4+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+, two equivalent Ca2+, and one Zr4+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Ca2+, one Zr4+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one Ca2+, and two Zr4+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one Zr4+, and one O2- atom. The O–O bond length is 1.50 Å. In the fourteenth O2- site, O2- is bonded in a 5-coordinate geometry to one Na1+, one Ca2+, two equivalent Zr4+, and one O2- atom. In the fifteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ca2+ and two equivalent Zr4+ atoms. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+, one Ca2+, and one Si4+ atom. In the second F1- site, F1- is bonded in a 1-coordinate geometry to three Na1+ and one Si4+ atom. In the third F1- site, F1- is bonded in a 2-coordinate geometry to one Na1+ and one Si4+ atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on Na3Ca3Zr2Si4(O5F)3 by Materials Project. https://doi.org/10.17188/1286001

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↗