Two-dimensional layered lithium lanthanum titanium oxide/graphene-like composites as electrodes for lithium-ion batteries

Abstract

Perovskite-structured (ABO₃) lithium lanthanum titanate (Li_xLa_(2−x)/3TiO₃, LLTO) is widely used in all solid state lithium ion batteries due to its high ionic conductivity. In this study, a two-dimensional LLTO nanosheet/graphene (LLTO/C) nanosheet composite has been designed as an electrode material for lithium-ion batteries (LIBs). LLTO/C not only exhibits the ionic conductivity properties of perovskite-type LLTO, but the graphene between the layers of LLTO nanosheets also endows the material with additional electronic conductivity. Moreover, LLTO@C-600 exhibits an excellent rate capability as the electrode for delithiation with a high specific capacity of 350 mA h g⁻¹ at 20 mA g⁻¹, and 70% of the specific capacity can be maintained at 1.0 A g⁻¹ after 800 cycles. The excellent electrochemical performances can be attributed to the superior interficial capacitive Li⁺ storage capability.