Preparation of ternary phase Li4Ti5O12/anatase/rutile nanocomposites with defects and their enhanced capability for lithium ion storage.

Abstract Developing anode materials that have high safety and high performance is essential for their application in Li ion batteries. Ternary phase Li 4 Ti 5 O 12 /rutile/anatase (N-LTO/A/R) nanocomposites that have abundant phase boundaries and structure defects are prepared via solvothermal synthesis and following calcination under an Ar/NH 3 atmosphere. With the introduction of multiple phases and defects, the as-prepared ternary phase nanocomposites display excellent lithium storage capability in a Li half-cell as well as in full-cell batteries. The nanocomposites deliver a reversible specific capacity of 149.0 mAh g−1 at a current density of 10 A g−1 and maintain about 85% of the specific capacity after 800 cycles at a higher rate of 5 A g−1 for the Li half-cell. Even in the Li ion full-cell, the as-prepared nanocomposites deliver specific capacities of 210 and 124 mAh g−1 at current densities of 0.05 and 1 A g−1, respectively. The extraordinary electrochemical performance of the N-LTO/A/R nanocomposites is attributed to the nanostructures, phase boundaries, presence of structure defects, and larger specific surface area, which favor facilitating lithium ion diffusion and electron transfer. This study shows that the ternary phase nanocomposites are very promising as a high-performance anode in lithium ion batteries. Highlights • Li 4 Ti 5 O 12 /anatase/rutile with structural defects prepared by NH 3 /Ar atmosphere. • Superior rate performance and cycle stability in Li-ion half-cell and full-cell. • Performance enhanced by the combination of phase boundaries and defects. [ABSTRACT FROM AUTHOR]