Promising High-Durability Anode for Lithium-Ion Batteries Using Optimally Sized Silicon Particles Embedded in TiO₂ Nanotubes

Silicon (Si) is a highly promising anode material for Li-ion batteries due to its exceptional theoretical capacity; however, its practical application is hindered by significant volume expansion and low electrical conductivity. In this study, anodic oxidation was employed to fabricate well-organized open TiO₂ nanotubes (ONTs) as a scaffold, enabling the deposition of nanoscale Si particles with precisely controlled dimensions. The uniform distribution and reduced size of Si nanoparticles (NPs) significantly mitigated mechanical stress during lithiation/delithiation cycles, enhancing electrode stability. Optimized Si/ONT electrodes achieved areal capacity of 310 μAh/cm² at a current density of 65 μA/cm² over 50 cycles—five times greater than bare ONTs and superior to conventional Si-based anodes. Additionally, the electrodes exhibited excellent cycling stability (308 μAh/cm² at 100 cycles) and high-rate capability, with a capacity of 185 μAh/cm² at 500 μA/cm². These results were achieved without the need for electrolyte additives, highlighting the intrinsic electrochemical stability of the Si/ONTs. This work demonstrates that the combination of anodic oxidation for TNT synthesis and the controlled deposition of Si NPs presents a scalable and effective strategy for the development of high-performance, durable Li-ion battery anodes.