Search NASA⌕ Search

DOE OSTI · 1274717

Materials Data on Hg6BiSb4Br7 by Materials Project

Abstract

Hg6Sb4BiBr7 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. Hg2+ is bonded in a 5-coordinate geometry to two Sb2- and three equivalent Br1- atoms. There are one shorter (2.73 Å) and one longer (2.75 Å) Hg–Sb bond lengths. There are a spread of Hg–Br bond distances ranging from 3.41–3.57 Å. Bi3+ is bonded in an octahedral geometry to six equivalent Br1- atoms. All Bi–Br bond lengths are 2.90 Å. There are two inequivalent Sb2- sites. In the first Sb2- site, Sb2- is bonded to three equivalent Hg2+ and one Sb2- atom to form corner-sharing SbHg3Sb tetrahedra. The Sb–Sb bond length is 2.92 Å. In the second Sb2- site, Sb2- is bonded to three equivalent Hg2+, one Sb2-, and one Br1- atom to form distorted SbHg3SbBr trigonal bipyramids that share corners with three equivalent SbHg3Sb tetrahedra and a cornercorner with one SbHg3SbBr trigonal bipyramid. The Sb–Br bond length is 3.15 Å. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 4-coordinate geometry to three equivalent Hg2+ and one Bi3+ atom. In the second Br1- site, Br1- is bonded in a linear geometry to two equivalent Sb2- atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-30. Materials Data on Hg6BiSb4Br7 by Materials Project. https://doi.org/10.17188/1274717

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↗