Binder-free TiO2 anode electrodes by micro-arc oxidation for Li-ion battery

Titanium dioxide (TiO₂) has attracted widespread attention as a promising alternative anode for Li-ion batteries (LIBs) due to its low volume change, excellent operation safety, good discharge potential, green technology, and low cost. In this work, a TiO₂ film was created on a Ti substrate by a one-step micro-arc oxidation (MAO) technique in a phosphate-based electrolyte, and it is specifically utilized as a binder-free anode for LIBs. The battery performance demonstrated a high sustained capacity of 270 µAh/cm² at a current density of 50 µA/cm², attributed to the porous morphology of the TiO₂ sample prepared at an optimized voltage, and excellent cycling stability over 200 cycles. Moreover, the capacity was restored to 90% of its initial capacity during cycling at a high current density of 500 µA/cm², illustrating good rate capability. Overall, the porous structure of TiO₂, along with the channels and cavities generated during the MAO process, serves as penetration pathways for lithium ions and provides surface-active sites for electrochemical reactions. This study presents a high-performance, cost-effective approach to developing binder-free anodes for LIBs with superior performance.