title: Phase-selective synthesis of nickel phosphide in high-boiling solvent for all-solid-state lithium secondary batteries.
abstract: Nickel phosphide particles were synthesized by thermal decomposition of a nickel precursor in a mixed solution of trioctylphosphine and trioctylphosphine oxide. The crystal phase and morphology of samples prepared by changing the solvents, the amount of trioctylphosphine as a phosphorus source, the reaction temperature, and the nickel precursor were characterized using X-ray diffraction and transmission electron microscopy. Spherical Ni(5)P(4) particles with diameters of 500 nm were obtained using nickel acetylacetonate as a nickel precursor at 360 °C for 1 h in trioctylphosphine oxide. NiP(2) particles with diameters of 200-500 nm were obtained using nickel acetate tetrahydrate at 360 °C for 5 h in trioctylphosphine oxide. All-solid-state cells were fabricated using NiP(2) particles as an active material and 80Li(2)S·20P(2)S(5) (mol %) glass-ceramic as a solid electrolyte. The Li-In/80Li(2)S·20P(2)S(5)/NiP(2) cell exhibited an initial discharge capacity of 1100 mAh g(-1) at a current density of 0.13 mA cm(-2) and retained a discharge capacity of 750 mAh g(-1) after 10 cycles.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Aso
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Hayashi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tatsumisago