Freestanding Nanoengineered [001] Preferentially Oriented TiO₂ Nanosheets−Graphene Planarly Aligned Nanohybrids with Enhanced Li-Storage Properties

A freestanding film electrode comprising face-to-face alternately stacked 2D TiO₂ nanosheets and reduced graphene oxide (rGO) is designed and fabricated as a binder-free anode for lithium-ion batteries. The ultrathin TiO₂ nanosheets, with (001) facets exposed were face-to-face hetero-assembled onto the conductive rGO, allowing Li⁺ to swiftly diffuse into the TiO₂ nanosheets across the (001) facets with the lowest barrier and a short transfer distance. The configuration of this planar-aligned electrode leads to superior lithium performance, which delivers a large capacity of 132.3 mA h g⁻¹ with a capacity retention of 89 % over 1000 cycles at a high rate of 20 C (1 C=168 mA g⁻¹). This work proves that controlling the arrangement orientation of electrode materials with an anisotropy Li⁺ diffusion barrier could remarkably improve the electrochemical properties, for promising applications in high-power energy-storage devices.