A preliminary investigation of fracture toughness of Li7La3Zr2O12 and its comparison to other solid Li-ionconductors

This is the first report of fracture toughness analysis of a new ceramic electrolyte (Li7La3Zr2O12). The fracture toughness was measured using an indentation technique and subsurface crack propagation was analyzed using a novel focused ion beam/scanning electron microscope (FIB–SEM) technique. The fracture toughness of polycrystalline Li7La3Zr2O12 was between 0.86–1.63 MPa√m. FIB–SEM analysis of the indentation cracks suggested that both half-penny and Palmquist cracks were present. The fracture toughness of Li7La3Zr2O12 is comparable to other state of the art ceramic electrolytes such as Li0.33La0.57TiO3 and Li1.3Al0.3Ti1.7(PO4)3.

► This is the first fracture analysis of the ceramic electrolyte Li7La3Zr2O12.
► The fracture toughness of Li7La3Zr2O12 ranges between 0.86–1.63 MPa√m.
► Half-penny and Palmquist cracks were observed using FIB/SEM analysis.