Hierarchical architectures of TiO₂ nanowires—CNT interpenetrating networks as high-rate anodes for lithium-ion batteries

Two hierarchical hybrid nanostructures consisting of TiO₂ nanowires /nanoparticles that interact with carbon nanotubes (CNTs) have been designed and synthesized via an in situ solvothermal method, following a simple thermal treatment. The TiO₂ nanowires were grown among the gap in the CNT networks, forming three-dimensional interpenetrating network composites. The TiO₂ nanoparticles adhered to the surface of the CNT to develop a ‘coating’ CNT network. The two composites with different structures were evaluated as electrodes for lithium-ion storage upon testing in a Li electrochemical half-cell. Compared with the nanoparticle composites, the composite electrodes of the nanowires demonstrated higher capacities (over 150 mA h g⁻¹ at a current density of 0.5 C) and better rate capabilities (over 80 mA h g⁻¹ at 10 C) due to its larger surface active sites and shorter diffusion paths for Li⁺. These results imply that the special structure is promising as anode materials for energy application. (paper)