Binder-free SnO2–TiO2 composite anode with high durability for lithium-ion batteries

A SnO2–TiO2 electrode was prepared via anodization and subsequent anodic potential shock for a binder-free anode for lithium-ion battery applications. Perpendicularly oriented TiO2 microcones are formed by anodization; SnO2, originating in a Na2SnO3 precursor, is then deposited in the valleys between the microcones and in their hollow cores by anodic potential shock. This sequence is confirmed by SEM and TEM analyses and EDS element mapping. The SnO2–TiO2 binder-free anode is evaluated for its C-rate performance and long-term cyclability in a half-cell measurement apparatus. The SnO2–TiO2 anode exhibits a higher specific capacity than the one with pristine TiO2 microcones and shows excellent capacity recovery during the rate capability test. The SnO2–TiO2 microcone structure shows no deterioration caused by the breakdown of electrode materials over 300 cycles. The charge/discharge capacity is at least double that of the TiO2 microcone material in a long-term cycling evaluation.