A lithium ion conductor in Li4SiO4 Li3PO4 LiBO2 ternary system
Abstract We developed a lithium ion conductor in Li 4 SiO 4 Li 3 PO 4 LiBO 2 ternary ceramic system comprising of the mole ratio as Li 4 SiO 4 :Li 3 PO 4 :LiBO 2 60:40:20 (termed as 40LP 20B) exhibiting the ion conductivity of 5.7 x 10 6 s/cm at room temperature. From the X ray diffraction patterns, the ternary solid solution has the orthorhombic phase structure with the increased unit cell volume due to the substitution of boron in lattice. The SEM images show that the high densification of the 40LP 20B samples sintered at 900 degC for 6 h, and EDS mappings illustrate that the incorporating boron is distributed homogenously in the grains and no precipitated impurity was observed on grain surface or around grain boundaries. The data of electrochemical impedance spectroscopy (EIS) reveal the low resistance from grain boundary, giving rise to the high bulk ion conductivity. The lithium ion conductor in Li 4 SiO 4 Li 3 PO 4 LiBO 2 system is of great potential as practical solid electrolyte for all solid state battery.