The effect of annealing on TiO2 nanotube arrays as anode for lithium ion batteries by X-ray diffraction, field
emission scanning electron microscopy, cyclic voltammetry, galvanostatic charge-discharge testing, and electrochemical
impedance spectroscopy was investigated. The crystalline structure of TiO2 nanotube can be changed
by controlling the annealing temperature and the crystallization also has considerable effect on electrochemical
performance. Amorphous TiO2 annealed at 250 C shows the highest discharge capacity in coin cell tests with
a discharge capacity of about 67 Ah cm−2 and good cycling stability during 50 charge-discharge cycles. The
electrochemical impedance spectroscopy results show the smallest resistance compared to the other samples.