Fracture toughness of single grains and polycrystalline Li7La3Zr2O12 electrolyte material based on a pillar splitting method

Abstract

In the present study an advanced pillar splitting method is used to determine the fracture toughness of a garnet-type Li7La3Zr2O12 (LLZO) electrolyte. The obtained results are compared to data derived on the basis of conventional Vickers indentation. Furthermore, potential micro-pillar size effects are investigated. The estimated fracture toughness values for single grains and polycrystalline LLZO material obtained via both methods are in good agreement, yielding ∼ 1 MPa m0.5, hence the data indicate that LLZO exhibits relatively low fracture toughness and has a brittle behavior.