DOE OSTI2020
Li7(NiO2)11 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six NiO6 octahedra, edges with three LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 8–12°. There are a spread of Li–O bond distances ranging from 2.03–2.24 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six NiO6 octahedra, edges with two equivalent LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 9–15°. There are four shorter (2.09 Å) and two longer (2.16 Å) Li–O bond lengths. In the third Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six NiO6 octahedra, edges with three LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 10–13°. There are a spread of Li–O bond distances ranging from 2.06–2.17 Å. In the fourth Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six NiO6 octahedra, edges with three LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 8–12°. There are a spread of Li–O bond distances ranging from 2.06–2.19 Å. There are six inequivalent Ni+3.36+ sites. In the first Ni+3.36+ site, Ni+3.36+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three LiO6 octahedra, edges with four LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 10–11°. There are a spread of Ni–O bond distances ranging from 1.87–2.09 Å. In the second Ni+3.36+ site, Ni+3.36+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with five LiO6 octahedra, edges with three LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 8–15°. There are a spread of Ni–O bond distances ranging from 1.88–2.01 Å. In the third Ni+3.36+ site, Ni+3.36+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three LiO6 octahedra, edges with four LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 8–10°. There are a spread of Ni–O bond distances ranging from 1.84–1.93 Å. In the fourth Ni+3.36+ site, Ni+3.36+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four LiO6 octahedra, edges with four LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 9–11°. There are a spread of Ni–O bond distances ranging from 1.86–1.98 Å. In the fifth Ni+3.36+ site, Ni+3.36+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four LiO6 octahedra, edges with four LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are a spread of Ni–O bond distances ranging from 1.88–2.06 Å. In the sixth Ni+3.36+ site, Ni+3.36+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four LiO6 octahedra, edges with four LiO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 10–13°. There are a spread of Ni–O bond distances ranging from 1.87–2.07 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the second O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+ and three Ni+3.36+ atoms. In the fourth O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the fifth O2- site, O2- is bonded to two equivalent Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the sixth O2- site, O2- is bonded to two equivalent Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the seventh O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the eighth O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the ninth O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the tenth O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids. In the eleventh O2- site, O2- is bonded to two Li1+ and three Ni+3.36+ atoms to form a mixture of edge and corner-sharing OLi2Ni3 square pyramids.