Engineering Papers⌕ Search

DOE OSTI · 1206822

Materials Data on CdBi3O7 by Materials Project

Abstract

CdBi3O7 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Cd2+ is bonded to four O2- atoms to form distorted CdO4 tetrahedra that share corners with three equivalent BiO7 hexagonal pyramids and corners with six equivalent CdO4 tetrahedra. There are a spread of Cd–O bond distances ranging from 2.26–2.30 Å. There are three inequivalent Bi4+ sites. In the first Bi4+ site, Bi4+ is bonded to seven O2- atoms to form distorted BiO7 hexagonal pyramids that share corners with three equivalent CdO4 tetrahedra and edges with six equivalent BiO7 hexagonal pyramids. There are a spread of Bi–O bond distances ranging from 2.29–2.47 Å. In the second Bi4+ site, Bi4+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.13–2.42 Å. In the third Bi4+ site, Bi4+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.33–2.41 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Bi4+ atoms. In the second O2- site, O2- is bonded to four Bi4+ atoms to form OBi4 tetrahedra that share corners with nine OBi4 tetrahedra and edges with six OCdBi3 tetrahedra. In the third O2- site, O2- is bonded to three equivalent Cd2+ and one Bi4+ atom to form corner-sharing OCd3Bi tetrahedra. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to three equivalent Bi4+ atoms. In the fifth O2- site, O2- is bonded to one Cd2+ and three equivalent Bi4+ atoms to form a mixture of distorted edge and corner-sharing OCdBi3 tetrahedra. In the sixth O2- site, O2- is bonded to four Bi4+ atoms to form distorted OBi4 tetrahedra that share corners with nine OCdBi3 tetrahedra and edges with three equivalent OBi4 tetrahedra. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Bi4+ atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-07-20. Materials Data on CdBi3O7 by Materials Project. https://doi.org/10.17188/1206822

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↗