All-Solid-State Lithium Ion Batteries Using Self-Organized TiO₂ Nanotubes Grown from Ti-6Al-4V Alloy

All-solid-state batteries were fabricated by assembling a layer of self-organized TiO₂ nanotubes grown on as anode, a thin-film of polymer as an electrolyte and separator, and a layer of composite LiFePO₄ as a cathode. The synthesis of self-organized TiO₂ NTs from Ti-6Al-4V alloy was carried out via one-step electrochemical anodization in a fluoride ethylene glycol containing electrolytes. The electrodeposition of the polymer electrolyte onto anatase TiO₂ NTs was performed by cyclic voltammetry. The anodized Ti-6Al-4V alloys were characterized by scanning electron microscopy and X-ray diffraction. The electrochemical properties of the anodized Ti-6Al-4V alloys were investigated by cyclic voltammetry and chronopotentiometry techniques. The full-cell shows a high first-cycle Coulombic efficiency of 96.8% with a capacity retention of 97.4% after 50 cycles and delivers a stable discharge capacity of 63 μAh cm^-2 μm^-1 (119 mAh g^-1) at a kinetic rate of C/10.