Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 1699526

Materials Data on KNaCl2 by Materials Project

View original source ↗Read source document ↗Export metadata ↓

Abstract

KNaCl2 is Caswellsilverite structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. K1+ is bonded to six equivalent Cl1- atoms to form KCl6 octahedra that share corners with six equivalent NaCl6 octahedra, edges with six equivalent KCl6 octahedra, and edges with six equivalent NaCl6 octahedra. The corner-sharing octahedral tilt angles are 6°. All K–Cl bond lengths are 3.13 Å. Na1+ is bonded to six equivalent Cl1- atoms to form NaCl6 octahedra that share corners with six equivalent KCl6 octahedra, edges with six equivalent KCl6 octahedra, and edges with six equivalent NaCl6 octahedra. The corner-sharing octahedral tilt angles are 6°. All Na–Cl bond lengths are 2.91 Å. Cl1- is bonded to three equivalent K1+ and three equivalent Na1+ atoms to form a mixture of edge and corner-sharing ClK3Na3 octahedra. The corner-sharing octahedral tilt angles are 0°.

Explore related subjects

36 MATERIALS SCIENCECl-K-Nacrystal structureKNaCl2

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-05-02. Materials Data on KNaCl2 by Materials Project. https://doi.org/10.17188/1699526

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2026

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↗