Preparing Two-Dimensional Ordered Li0.33La0.557TiO3 Crystal in Interlayer Channel of Thin Laminar Inorganic Solid-State Electrolyte towards Ultrafast Li+ Transfer

Inorganic superionic conductor holds great promise for high-performance all-solid-state lithium batteries. However, the ionic conductivity of traditional inorganic solid electrolytes (ISEs) is always unsatisfactory owing to the grain boundary resistance and large thickness. Here, a 13 mu m-thick laminar framework with approximate to 1.3 nm interlayer channels is fabricated by self-assembling rigid, hydrophilic vermiculite (Vr) nanosheets. Then, Li0.33La0.557TiO3 (LLTO) precursors are impregnated in interlayer channels and afterwards in situ sintered to large-size, oriented, and defect-free LLTO crystal. We demonstrate that the confinement effect permits ordered arrangement of LLTO crystal along the c-axis (the fastest Li+ transfer direction), permitting the resultant 15 mu m-thick Vr-LLTO electrolyte an ionic conductivity of 8.22x10(-5) S cm(-1) and conductance of 87.2 mS at 30 degrees C. These values are several times' higher than that of traditional LLTO-based electrolytes. Moreover, Vr-LLTO electrolyte has a compressive modulus of 1.24 GPa. Excellent cycling performance is demonstrated with all-solid-state Li/LiFePO4 battery.

Automated summary

A 13 µm-thick laminar framework with 1.3 nm interlayer channels was fabricated by self-assembling vermiculite nanosheets, enabling high ionic conductivity of the LLTO electrolyte for all-solid-state lithium batteries. The ordered arrangement of LLTO crystal along the c-axis significantly enhances Li+ transfer and leads to excellent cycling performance.