Hierarchical TiO2-B nanowire@α-Fe2O3 nanothorn core-branch arrays as superior electrodes for lithium-ion microbatteries

This paper reports a simple yet efficient method for the synthesis of hierarchical TiO 2 -B nanowire@α-Fe 2 O 3 nanothorn core-branch arrays based on a stepwise hydrothermal approach. The as-fabricated hybrid arrays show impressive performance as a high-capacity anode for lithium-ion batteries. The key design in this study is a core-branch hybrid architecture, which not only provides large surface active sites for lithium ion insertion/extraction, but also enables fast charge transport owing to the reduced diffusion paths for both electrons and lithium ions. The peculiar combination of attributes of TiO 2 (good structural stability) and Fe 2 O 3 (large specific capacity) provides the hybrid array electrodes with several desirable electrochemical features: large reversible capacity (∼800 mA·h·g −1 for specific mass capacity and ∼750 μA·h·cm −2 for specific areal capacity), good cycling stability, and high rate capability. The impressive electrochemical performance, together with the facile synthesis procedure, may provide an efficient platform to integrate the TiO 2 nanowire@Fe 2 O 3 nanothorn core-branch arrays as a three-dimensional thin film electrode for lithium-ion microbatteries.