Iron supported C@Fe ₃O ₄ nanotube array: A new type of 3D anode with low-cost for high performance lithium-ion batteries

Rational design and engineering of materials and/or structures for novel electrodes leading to next-generation lithium-ion batteries with high energy and power densities is a major challenge to the ever-growing needs of the electronic and automobile industries. To tackle this issue, we have designed a new type of 3D anode by anodization of iron foil to form a highly ordered Fe ₃O ₄ nanotube array directly on a low-cost current collector (Fe foil) followed by carbonization of pre-adsorbed glucose on the nanotube array at 500 °C. In such an electrode, each part plays its desired role, with the Fe foil being a low cost and stable current collector, Fe ₃O ₄ working as a high-capacity active material, and the carbon coating forming an electron conducting network and stable solid electrolyte interface. High capacity (1020 μA h cm ^-2 at 20 μA cm ^-2) and high rate capability (176 μA h cm ^-2 at 1000 μA cm ^-2) were achieved in this newly designed electrode. Overall, the results described in this work provide a promising route to facile and large-scale production of a low-cost 3D composite electrode with enhanced electrochemical performance.