Challenges to Li7La3Zr2O12 system electrolyte and the modification: From powder to ceramic

The solid-state electrolyte Li7La3Zr2O12(LLZO) system exhibits high ionic conductivity, good resistance to lithium filament growth, exceptional chemical stability with electrode enabling the direct use of lithium metal as an anode, thereby enhancing the energy density of batteries. Solid-state battery using LLZO electrolyte from powder to ceramic forms, holds promise as a replacement for traditional Li-ion batteries in both vehicular power and consumer electronics owing to its outstanding stability and high energy density. However, despite these promising attributes, the practical application of LLZO electrolytes faces a spectrum of challenges. Foremost among these are reaction with H2O/CO2, interface problems and lithium filament growth. This review comprehensively summarizes these challenges and the modification methods employed to surmount them, spanning from powder to ceramic forms of application. Furthermore, this review outlines three future directions aimed at overcoming the aforementioned challenges, providing guidance for enhanced practical application of LLZO electrolytes in solid-state batteries.