Lithium ion conduction in doped LaLiO2 system
Abstract Solid solutions of the lithium ion conductor LaLiO 2 were synthesized using a solid-state reaction method. For the strontium-doped system, Sr 2 + was partially doped at the La sites with the composition La 1 −  x Sr x Li 1 +  x O 2 ( x  = 0.1, 0.2), which introduced excess lithium into the structure, while for the magnesium-doped system, Mg 2 + was partially doped at the Li + site with LaLi 1 − 2 y Mg y O 2 ( y  = 0.1, 0.2) which introduced Li + vacancies. The magnesium-doped sample with y  = 0.1 in LaLi 1 − 2 y Mg y O 2 showed higher ionic conductivity of 9.22 × 10 − 5  S cm − 1 than that of the respective Sr doped sample of x  = 0.1 in La 1 −  x Sr x Li 1 +  x O 2 (4.64 × 10 − 5  S cm − 1 ) at 300 °C. Higher ionic conductivity in the Mg doped system indicates that vacancies led to high lithium ion conduction in LaLiO 2 . The doped LaLiO 2 systems are a novel lithium conductive oxides family.