Search NASA⌕ Search

DOE OSTI · 1298831

Materials Data on Li4Ti2Mn7O18 by Materials Project

Abstract

Li4Ti2Mn7O18 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.06–2.47 Å. In the second Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.24–2.62 Å. In the third Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.24–2.62 Å. In the fourth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.06–2.47 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent MnO6 octahedra, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Ti–O bond distances ranging from 1.92–2.08 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent MnO6 octahedra, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Ti–O bond distances ranging from 1.88–2.09 Å. There are eight inequivalent Mn+3.43+ sites. In the first Mn+3.43+ site, Mn+3.43+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There is two shorter (1.91 Å) and four longer (2.08 Å) Mn–O bond length. In the second Mn+3.43+ site, Mn+3.43+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with six MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 52–65°. There are four shorter (1.99 Å) and one longer (2.08 Å) Mn–O bond lengths. In the third Mn+3.43+ site, Mn+3.43+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent MnO5 square pyramids, and edges with four MnO6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are a spread of Mn–O bond distances ranging from 1.93–2.00 Å. In the fourth Mn+3.43+ site, Mn+3.43+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four MnO5 square pyramids, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–1.97 Å. In the fifth Mn+3.43+ site, Mn+3.43+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four MnO5 square pyramids, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. There is two shorter (1.93 Å) and four longer (1.95 Å) Mn–O bond length. In the sixth Mn+3.43+ site, Mn+3.43+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent MnO5 square pyramids, and edges with four MnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Mn–O bond distances ranging from 1.94–1.98 Å. In the seventh Mn+3.43+ site, Mn+3.43+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with six MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Mn–O bond distances ranging from 1.98–2.09 Å. In the eighth Mn+3.43+ site, Mn+3.43+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There is two shorter (1.92 Å) and four longer (2.07 Å) Mn–O bond length. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.43+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+ and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded to two equivalent Li1+, two equivalent Ti4+, and one Mn+3.43+ atom to form distorted OLi2Ti2Mn trigonal bipyramids that share corners with six OLiTiMn2 trigonal pyramids and edges with two equivalent OLi2Ti2Mn trigonal bipyramids. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and three Mn+3.43+ atoms. In the fifth O2- site, O2- is bonded to one Li1+ and three Mn+3.43+ atoms to form distorted OLiMn3 trigonal pyramids that share corners with four OLi2Ti2Mn trigonal bipyramids and corners with two equivalent OLiMn3 trigonal pyramids. In the sixth O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.43+ atoms to form a mixture of edge and corner-sharing OLi2Mn3 trigonal bipyramids. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three Mn+3.43+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ti4+ and two equivalent Mn+3.43+ atoms. In the ninth O2- site, O2- is bonded to one Li1+, one Ti4+, and two equivalent Mn+3.43+ atoms to form distorted OLiTiMn2 trigonal pyramids that share corners with two equivalent OLi2Ti2Mn trigonal bipyramids, corners with two equivalent OLiTiMn2 trigonal pyramids, and edges with two equivalent OLi2Mn3 trigonal bipyramids. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one Ti4+, and two equivalent Mn+3.43+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ti4+ and two equivalent Mn+3.43+ atoms. In the twelfth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three Mn+3.43+ atoms. In the thirteenth O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.43+ atoms to form OLi2Mn3 trigonal bipyramids that share corners with two equivalent OLi2Mn3 trigonal bipyramids, edges with three equivalent OLi2Mn3 trigonal bipyramids, and edges with two equivalent OLiTiMn2 trigonal pyramids. In the fourteenth O2- site, O2- is bonded to one Li1+ and three Mn+3.43+ atoms to form distorted OLiMn3 trigonal pyramids that share corners with four OLi2Ti2Mn trigonal bipyramids and corners with two equivalent OLiMn3 trigonal pyramids. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and three Mn+3.43+ atoms. In the sixteenth O2- site, O2- is bonded to two equivalent Li1+, two equivalent Ti4+, and one Mn+3.43+ atom to form distorted OLi2Ti2Mn trigonal bipyramids that share corners with four OLiMn3 trigonal pyramids and edges with two equivalent OLi2Ti2Mn trigonal bipyramids. In the seventeenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+ and two equivalent Ti4+ atoms. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.43+ atoms.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

2020-04-29. Materials Data on Li4Ti2Mn7O18 by Materials Project. https://doi.org/10.17188/1298831

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↗