Search NASA⌕ Search

DOE OSTI · 1654316

Materials Data on Sr2Zn5Si3 by Materials Project

Abstract

Sr2Zn5Si3 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 8-coordinate geometry to twelve Zn and four equivalent Si atoms. There are a spread of Sr–Zn bond distances ranging from 3.27–3.49 Å. All Sr–Si bond lengths are 3.26 Å. In the second Sr site, Sr is bonded in a 8-coordinate geometry to eight Zn and eight Si atoms. There are four shorter (3.39 Å) and four longer (3.41 Å) Sr–Zn bond lengths. There are four shorter (3.25 Å) and four longer (3.26 Å) Sr–Si bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded in a 2-coordinate geometry to four Sr, two equivalent Zn, and two equivalent Si atoms. Both Zn–Zn bond lengths are 2.61 Å. Both Zn–Si bond lengths are 2.58 Å. In the second Zn site, Zn is bonded to four Sr and four Si atoms to form a mixture of distorted edge and face-sharing ZnSr4Si4 tetrahedra. All Zn–Si bond lengths are 2.57 Å. In the third Zn site, Zn is bonded in a distorted single-bond geometry to four equivalent Sr, four equivalent Zn, and one Si atom. The Zn–Si bond length is 2.48 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to four equivalent Sr, four equivalent Zn, and one Si atom. The Si–Si bond length is 2.41 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to four equivalent Sr, four equivalent Zn, and one Si atom. In the third Si site, Si is bonded in a 9-coordinate geometry to four equivalent Sr and five Zn atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-20. Materials Data on Sr2Zn5Si3 by Materials Project. https://doi.org/10.17188/1654316

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↗