Binder–Free Nanotubular Hetero‐Structured Anodes of α–Fe2O3 (Hematite) and TiN for Li–Ion Battery

Hematite (α‐Fe2O3) has attracted considerable attention as an anode material due to its high theoretical capacity (1,007 mAhg−1), low cost, and non‐toxicity. The conversion reaction, which often leads to the pulverization of hematite and degradation of electrochemical performances (e. g., capacity retention, high rate capability), is also found in hematite as Fe2O3 + 6Li+ + 6e– → 2Fe + Li2O. Here, we synthesized nanotubular hetero‐structures using α‐Fe2O3 and TiN via atomic layer deposition (ALD) without any binders. The initial reversible charge capacity of Fe2O3@TiN nanotubes (NTs) was 952 mAhg−1 with a retention of 673 mAhg−1 after 30 cycles. Porous Fe2O3 NTs with conductive TiN NTs exhibited enhanced electrochemical performances when used as an anode material. α‐Fe2O3@TiN hetero‐structured nanotubes were synthesized via a template‐directed method together with atomic layer deposition (ALD) and used as an anode in a lithium ion battery. In this work, the microstructure of the ALD‐grown α‐Fe2O3@TiN hetero‐structured nanotube electrode was analysed, and its cyclic performance with different wall thicknesses was evaluated. The conductive TiN coating by ALD on the nanotube electrode significantly improved its electrochemical performance.