Mesoporous and Nanostructured TiO 2 layer with Ultra‐High Loading on Nitrogen‐Doped Carbon Foams as Flexible and Free‐Standing Electrodes for Lithium‐Ion Batteries

A simple and green method is developed for the preparation of nanostructured TiO 2 supported on nitrogen‐doped carbon foams (NCFs) as a free‐standing and flexible electrode for lithium‐ion batteries (LIBs), in which the TiO 2 with 2.5–4 times higher loading than the conventional TiO 2 ‐based flexible electrodes acts as the active material. In addition, the NCFs act as a flexible substrate and efficient conductive networks. The nanocrystalline TiO 2 with a uniform size of ≈10 nm form a mesoporous layer covering the wall of the carbon foam. When used directly as a flexible electrode in a LIB, a capacity of 188 mA h g −1 is achieved at a current density of 200 mA g −1 for a potential window of 1.0–3.0 V, and a specific capacity of 149 mA h g −1 after 100 cycles at a current density of 1000 mA g −1 is maintained. The highly conductive NCF and flexible network, the mesoporous structure and nanocrystalline size of the TiO 2 phase, the firm adhesion of TiO 2 over the wall of the NCFs, the small volume change in the TiO 2 during the charge/discharge processes, and the high cut‐off potential contribute to the excellent capacity, rate capability, and cycling stability of the TiO 2 /NCFs flexible electrode.