Engineering Papers⌕ Search

DOE OSTI · 1725186

Materials Data on MgCd5 by Materials Project

Abstract

MgCd5 crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Mg is bonded to twelve Cd atoms to form MgCd12 cuboctahedra that share corners with eighteen equivalent CdMg3Cd9 cuboctahedra, edges with six equivalent MgCd12 cuboctahedra, edges with twelve CdMg2Cd10 cuboctahedra, faces with two equivalent MgCd12 cuboctahedra, and faces with eighteen CdMg2Cd10 cuboctahedra. There are six shorter (3.09 Å) and six longer (3.24 Å) Mg–Cd bond lengths. There are three inequivalent Cd sites. In the first Cd site, Cd is bonded to two equivalent Mg and ten Cd atoms to form CdMg2Cd10 cuboctahedra that share corners with eighteen equivalent CdMg2Cd10 cuboctahedra, edges with four equivalent MgCd12 cuboctahedra, edges with fourteen CdMg2Cd10 cuboctahedra, faces with four equivalent MgCd12 cuboctahedra, and faces with sixteen CdMg2Cd10 cuboctahedra. There are six shorter (3.09 Å) and four longer (3.23 Å) Cd–Cd bond lengths. In the second Cd site, Cd is bonded to two equivalent Mg and ten Cd atoms to form CdMg2Cd10 cuboctahedra that share corners with eighteen CdMg2Cd10 cuboctahedra, edges with four equivalent MgCd12 cuboctahedra, edges with fourteen CdMg2Cd10 cuboctahedra, faces with four equivalent MgCd12 cuboctahedra, and faces with sixteen CdMg2Cd10 cuboctahedra. There are three shorter (3.09 Å) and four longer (3.23 Å) Cd–Cd bond lengths. In the third Cd site, Cd is bonded to three equivalent Mg and nine Cd atoms to form distorted CdMg3Cd9 cuboctahedra that share corners with nine equivalent MgCd12 cuboctahedra, corners with nine equivalent CdMg3Cd9 cuboctahedra, edges with eighteen CdMg2Cd10 cuboctahedra, faces with three equivalent MgCd12 cuboctahedra, and faces with seventeen CdMg2Cd10 cuboctahedra. All Cd–Cd bond lengths are 3.09 Å.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-02. Materials Data on MgCd5 by Materials Project. https://doi.org/10.17188/1725186

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↗