Search NASA⌕ Search

DOE OSTI · 1736954

Materials Data on CaMnAl4SiP3(HO4)5 by Materials Project

Abstract

CaMnAl4SiP3H5O18O2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional and consists of four hydrogen peroxide molecules and one CaMnAl4SiP3H5O18 framework. In the CaMnAl4SiP3H5O18 framework, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.63 Å. Mn2+ is bonded in a 6-coordinate geometry to two equivalent H1+ and four O2- atoms. Both Mn–H bond lengths are 1.95 Å. There are a spread of Mn–O bond distances ranging from 1.86–2.12 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two equivalent PO4 tetrahedra and an edgeedge with one AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.76–1.93 Å. In the second Al3+ site, Al3+ is bonded to two H1+ and three O2- atoms to form distorted AlH2O3 trigonal bipyramids that share corners with two equivalent SiHO3 tetrahedra and an edgeedge with one AlH2O3 trigonal bipyramid. There is one shorter (1.67 Å) and one longer (1.70 Å) Al–H bond length. There are a spread of Al–O bond distances ranging from 1.83–1.91 Å. Si4+ is bonded to one H1+ and three O2- atoms to form SiHO3 tetrahedra that share corners with four equivalent AlH2O3 trigonal bipyramids. The Si–H bond length is 1.48 Å. There is two shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.51 Å) and one longer (1.77 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AlO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.63 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one Si4+ atom. In the third H1+ site, H1+ is bonded in a bent 120 degrees geometry to one Mn2+ and one Al3+ atom. In the fourth H1+ site, H1+ is bonded in a water-like geometry to two equivalent Al3+ atoms. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Al3+ and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one Al3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a linear geometry to one Al3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Mn2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to one Al3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Al3+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one P5+ and one O2- atom. The O–O bond length is 1.51 Å. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mn2+ and two equivalent Al3+ atoms. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to one Mn2+ and one H1+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Al3+, and one O2- atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on CaMnAl4SiP3(HO4)5 by Materials Project. https://doi.org/10.17188/1736954

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↗