Synthesis of TiO₂ hollow nanofibers by co-axial electrospinning and its superior lithium storage capability in full-cell assembly with olivine phosphate

We report the formation and extraordinary Li-storage properties of TiO ₂ hollow nanofibers by co-axial electrospinning in both the half-cell and full-cell configurations. Li-insertion properties are first evaluated as anodes in the half-cell configuration (Li/TiO₂ hollow nanofibers) and we found that reversible insertion of ∼0.45 moles is feasible at a current density of 100 mA g^-1. The half-cell displayed a good cyclability and retained 84% of its initial reversible capacity after 300 galvanostatic cycles. The full-cell is fabricated with a commercially available olivine phase LiFePO₄ cathode under optimized mass loading. The LiFePO ₄/TiO₂ hollow nanofiber cell delivered a reversible capacity of 103 mA h g^-1 at a current density of 100 mA g ^-1 with an operating potential of ∼1.4 V. Excellent cyclability is noted for the full-cell configuration, irrespective of the applied current densities, and it retained 88% of reversible capacity after 300 cycles in ambient conditions at a current density of 100 mA g^-1.