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.