Interface-engineered all-solid-state Li-ion batteries based on garnet-type fast Li+ conductors

Abstract

All-solid-state Li-ion batteries based on Li7La3Zr2O12 (LLZO) garnet structures require novel electrode assembly strategies to guarantee a proper Li+ transfer at the electrode–electrolyte interfaces. Here, first stable cell performances are reported for Li-garnet, c-Li6.25Al0.25La3Zr2O12, all-solid-state batteries running safely with a full ceramics setup, exemplified with the anode material Li4Ti5O12. Novel strategies to design an enhanced Li+ transfer at the electrode–electrolyte interface using an interface-engineered all-solid-state battery cell based on a porous garnet electrolyte interface structure, in which the electrode material is intimately embedded, are presented. The results presented here show for the first time that all-solid-state Li-ion batteries with LLZO electrolytes can be reversibly charge–discharge cycled also in the low potential ranges (≈1.5 V) for combinations with a ceramic anode material. Through a model experiment, the interface between the electrode and electrolyte constituents is systematically modified revealing that the interface engineering helps to improve delivered capacities and cycling properties of the all-solid-state Li-ion batteries based on garnet-type cubic LLZO structures.