Search NASA⌕ Search

DOE OSTI · 1751266

Materials Data on K2Co(B2O5)6 by Materials Project

Abstract

K2Co(B2O5)6 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. K is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of K–O bond distances ranging from 2.74–2.94 Å. Co is bonded to six O atoms to form distorted CoO6 octahedra that share corners with four BO4 tetrahedra. There are a spread of Co–O bond distances ranging from 1.77–2.49 Å. There are six inequivalent B sites. In the first B site, B is bonded to four O atoms to form BO4 tetrahedra that share a cornercorner with one CoO6 octahedra and a cornercorner with one BO4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of B–O bond distances ranging from 1.42–1.63 Å. In the second B site, B is bonded in a trigonal planar geometry to three O atoms. There are a spread of B–O bond distances ranging from 1.36–1.39 Å. In the third B site, B is bonded to four O atoms to form BO4 tetrahedra that share a cornercorner with one CoO6 octahedra and a cornercorner with one BO4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of B–O bond distances ranging from 1.43–1.57 Å. In the fourth B site, B is bonded in a trigonal planar geometry to three O atoms. All B–O bond lengths are 1.38 Å. In the fifth B site, B is bonded in a trigonal planar geometry to three O atoms. There are a spread of B–O bond distances ranging from 1.36–1.44 Å. In the sixth B site, B is bonded in a trigonal planar geometry to three O atoms. There are a spread of B–O bond distances ranging from 1.35–1.45 Å. There are fifteen inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to three B atoms. In the second O site, O is bonded in a distorted single-bond geometry to one K and one B atom. In the third O site, O is bonded in a bent 120 degrees geometry to two B atoms. In the fourth O site, O is bonded in a bent 120 degrees geometry to two B atoms. In the fifth O site, O is bonded in a distorted single-bond geometry to one K and one B atom. In the sixth O site, O is bonded in a distorted bent 120 degrees geometry to one K and two B atoms. In the seventh O site, O is bonded in a bent 120 degrees geometry to two B atoms. In the eighth O site, O is bonded in a distorted single-bond geometry to one K, one B, and one O atom. The O–O bond length is 1.36 Å. In the ninth O site, O is bonded in a distorted bent 120 degrees geometry to one K and two B atoms. In the tenth O site, O is bonded in a bent 120 degrees geometry to two B atoms. In the eleventh O site, O is bonded in a distorted bent 150 degrees geometry to one Co and one B atom. In the twelfth O site, O is bonded in a single-bond geometry to one O atom. The O–O bond length is 1.24 Å. In the thirteenth O site, O is bonded in a distorted bent 150 degrees geometry to one Co and one B atom. In the fourteenth O site, O is bonded in a distorted trigonal planar geometry to one K, one Co, and one O atom. In the fifteenth O site, O is bonded in an L-shaped geometry to one K and one O atom.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-30. Materials Data on K2Co(B2O5)6 by Materials Project. https://doi.org/10.17188/1751266

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↗