Three-Dimensional Nanoporous Fe(2)O(3)/Fe(3)C-Graphene Heterogeneous Thin Films for Lithium-Ion Batteries

[Image: see text] Three-dimensional self-organized nanoporous thin films integrated into a heterogeneous Fe(2)O(3)/Fe(3)C-graphene structure were fabricated using chemical vapor deposition. Few-layer graphene coated on the nanoporous thin film was used as a conductive passivation layer, and Fe(3)C was introduced to improve capacity retention and stability of the nanoporous layer. A possible interfacial lithium storage effect was anticipated to provide additional charge storage in the electrode. These nanoporous layers, when used as an anode in lithium-ion batteries, deliver greatly enhanced cyclability and rate capacity compared with pristine Fe(2)O(3): a specific capacity of 356 μAh cm(–2) μm(–1) (3560 mAh cm(–3) or ∼1118 mAh g(–1)) obtained at a discharge current density of 50 μA cm(–2) (∼0.17 C) with 88% retention after 100 cycles and 165 μAh cm(–2) μm(–1) (1650 mAh cm(–3) or ∼518 mAh g(–1)) obtained at a discharge current density of 1000 μA cm(–2) (∼6.6 C) for 1000 cycles were achieved. Meanwhile an energy density of 294 μWh cm(–2) μm(–1) (2.94 Wh cm(–3) or ∼924 Wh kg(–1)) and power density of 584 μW cm(–2) μm(–1) (5.84 W cm(–3) or ∼1834 W kg(–1)) were also obtained, which may make these thin film anodes promising as a power supply for micro- or even nanosized portable electronic devices.