Search NASA⌕ Search

DOE OSTI · 1705530

Materials Data on Ba6Si6CN14 by Materials Project

Abstract

Ba6Si6CN14 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are six inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to nine N+2.86- atoms. There are a spread of Ba–N bond distances ranging from 2.90–3.27 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine N+2.86- atoms. There are a spread of Ba–N bond distances ranging from 2.87–3.33 Å. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine N+2.86- atoms. There are a spread of Ba–N bond distances ranging from 2.85–3.27 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to nine N+2.86- atoms. There are a spread of Ba–N bond distances ranging from 2.88–3.35 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to nine N+2.86- atoms. There are a spread of Ba–N bond distances ranging from 2.87–3.36 Å. In the sixth Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine N+2.86- atoms. There are a spread of Ba–N bond distances ranging from 2.86–3.32 Å. There are six inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four N+2.86- atoms to form corner-sharing SiN4 tetrahedra. There is three shorter (1.73 Å) and one longer (1.74 Å) Si–N bond length. In the second Si4+ site, Si4+ is bonded to four N+2.86- atoms to form corner-sharing SiN4 tetrahedra. There is three shorter (1.73 Å) and one longer (1.74 Å) Si–N bond length. In the third Si4+ site, Si4+ is bonded to four N+2.86- atoms to form corner-sharing SiN4 tetrahedra. There is two shorter (1.72 Å) and two longer (1.74 Å) Si–N bond length. In the fourth Si4+ site, Si4+ is bonded to four N+2.86- atoms to form corner-sharing SiN4 tetrahedra. There are a spread of Si–N bond distances ranging from 1.72–1.74 Å. In the fifth Si4+ site, Si4+ is bonded to four N+2.86- atoms to form corner-sharing SiN4 tetrahedra. All Si–N bond lengths are 1.73 Å. In the sixth Si4+ site, Si4+ is bonded to four N+2.86- atoms to form corner-sharing SiN4 tetrahedra. There is three shorter (1.73 Å) and one longer (1.74 Å) Si–N bond length. There are three inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a linear geometry to two equivalent N+2.86- atoms. Both C–N bond lengths are 1.25 Å. In the second C4+ site, C4+ is bonded in a linear geometry to two equivalent N+2.86- atoms. Both C–N bond lengths are 1.25 Å. In the third C4+ site, C4+ is bonded in a linear geometry to two equivalent N+2.86- atoms. Both C–N bond lengths are 1.25 Å. There are twelve inequivalent N+2.86- sites. In the first N+2.86- site, N+2.86- is bonded in a distorted bent 120 degrees geometry to three Ba2+ and two Si4+ atoms. In the second N+2.86- site, N+2.86- is bonded in a distorted single-bond geometry to six Ba2+ and one C4+ atom. In the third N+2.86- site, N+2.86- is bonded in a distorted bent 120 degrees geometry to three Ba2+ and two Si4+ atoms. In the fourth N+2.86- site, N+2.86- is bonded in a distorted bent 120 degrees geometry to three Ba2+ and two Si4+ atoms. In the fifth N+2.86- site, N+2.86- is bonded in a distorted linear geometry to four Ba2+ and two Si4+ atoms. In the sixth N+2.86- site, N+2.86- is bonded in a distorted linear geometry to four Ba2+ and two Si4+ atoms. In the seventh N+2.86- site, N+2.86- is bonded in a single-bond geometry to six Ba2+ and one C4+ atom. In the eighth N+2.86- site, N+2.86- is bonded in a distorted single-bond geometry to six Ba2+ and one C4+ atom. In the ninth N+2.86- site, N+2.86- is bonded in a distorted bent 120 degrees geometry to three Ba2+ and two Si4+ atoms. In the tenth N+2.86- site, N+2.86- is bonded in a distorted bent 120 degrees geometry to three Ba2+ and two Si4+ atoms. In the eleventh N+2.86- site, N+2.86- is bonded in a distorted linear geometry to four Ba2+ and two Si4+ atoms. In the twelfth N+2.86- site, N+2.86- is bonded in a distorted bent 120 degrees geometry to three Ba2+ and two Si4+ atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on Ba6Si6CN14 by Materials Project. https://doi.org/10.17188/1705530

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↗