The solid electrolyte system, Li3PO4Li4SiO4

A lithium ion conductor in Li4SiO4-Li3PO4-LiBO2 ternary system

“…x P x O 4 with the composition of 0 b x b 0.12 is stable in the Li 4 SiO 4 monoclinic structure, while the Li 4 − x Si 1 − x P x O 4 with composition 0.12 b x b~0.6 is metastable in the orthorhombic structure similar to γ-Li 3 PO 4 12 . The ion conductivities of the solid solutions are several orders of magnitude greater than those of either end group.…”

“…The binary system of Li 3 PO 4 -Li 4 SiO 4 solid solution has been investigated extensively [10][11][12][13][14]. Li 4 SiO 4 material has the structure generally described in terms of isolated (SiO 4 ) 4− anionic clusters with ordered distribution of Li + ions over available cationic sites which are coordinated with 4, 5 or 6 oxygen atoms in a monoclinic unit cell (P21/m space group).…”

Synthesis and electrical property of Li2−FeSi1−P O4 as positive electrodes by spark-plasma-sintering process

“…Although the SPS process can significantly reduce the sintering period, the obtained samples are in a metastable state. The compositional dependence on the lattice parameters showed a formation of solid solutions between Li 4 SiO 4 and Li 3 PO 4 , in which Si was replaced by P. The solid solution region seems to be wider than those reported in the past [8]. The literature have described that Li 4 SiO 4 forms an extensive range of metastable solid solutions containing up to x ¼ 0.6.…”

“…However, the conductivity of x ¼ 0.5 by SPS was slightly higher than that of by SS due to the improved sintered density. It is known that the complex salts of Li 4 SiO 4 eLi 3 PO 4 exhibits much higher electrical conductivity than those of two end members, Li 4 SiO 4 and Li 3 PO 4 [8,13,14]. They have an ordered structure concerning Li þ ions, thus exhibiting a very low ionic conductivity.…”

“…The samples were prepared by spark-plasma-sintering (SPS) method and for comparison, the conventional solid state reaction (SS) to recognize the phase relationship of Li 4 SiO 4 and Li 3 PO 4 system which is available in the literature [8]. The chemical composition was controlled precisely by depressing the loss of Li as described in the Experimental section.…”