ic8b03155_si_001.pdf (1.12 MB)
High-Pressure Synthesis, Crystal Chemistry, and Ionic Conductivity of a Structural Polymorph of Li3BP2O8
journal contribution
posted on 2018-12-06, 14:35 authored by Eiichi Hirose, Kunimitsu Kataoka, Hiroshi Nagata, Junji Akimoto, Takuya Sasaki, Ken Niwa, Masashi HasegawaA new
structural polymorph of Li3BP2O8 has
been successfully synthesized via a solid-state reaction between Li3PO4 and BPO4 at 4 GPa and 600 °C.
The high-pressure phase of Li3BP2O8 (HP-Li3BP2O8) was found to crystallize
in monoclinic symmetry with the cell parameters of a = 8.57010(4) Å, b = 11.11812(5) Å, c = 5.55380(3) Å, and β = 97.7269(3)° [space
group P21/a (No. 14)].
HP-Li3BP2O8 has a new crystal structure
that has not been reported so far. The total ionic conductivities
measured for the polycrystalline sample by alternating-currrent impedance
were 3.4 × 10–7 and 2.1 × 10–6 S/cm at 399 and 456 K, respectively. The lithium ionic conductivity
of HP-Li3BP2O8 was higher than that
of the low-pressure phase Li3BP2O8 in the temperature range of 375–456 K. This is caused by
the difference in the dimensions of the lithium arrangements between
LP- and HP-Li3BP2O8.