Electrospun Fe2TiO5–TiO2@Graphene Nanofibers as Highly Durable Insertion Anode with Enhanced Lithium Storage Properties

Iron titanate is of considerable interest as a potential anode material for electrochemical energy storage and conversion. Herein, a fiber-like Fe 2 TiO 5 –TiO 2 @graphene (rGO–FTO–TO) hybrid structure is rationally designed and delicately fabricated by anchoring reduced graphene oxide (rGO) nanosheets on Fe 2 TiO 5 –TiO 2 (FTO–TO) nanofibers. The effective wrapping of rGO nanosheets can greatly improve the electrical conductivity and reduce the volume expansion. When evaluated as an anode, the rGO–FTO–TO exhibits remarkable lithium storage properties in terms of high capacity, long-term cycling stability, and excellent rate capability. Moreover, there exists a strong electrostatic interaction between rGO nanosheets and FTO–TO nanofibers by the introduction of aminopropyltriethoxysilane to induce the immobilization of a positively charged  NH 3 + group on the FTO–TO surface, promoting the bonding with negatively charged carboxylic acid (  COO − ) and hydroxyl (  OH) groups on the rGO. With strong electrostatic interaction, the rGO–FTO–TO exhibits appreciably enhanced initial capacity, elevated capacity retention, and high columbic efficiency compared with those of pristine FTO–TO nanofibers. This work provides a feasible strategy for fabricating a graphene-encapsulated FTO–TO fiber-like composite as a promising high-performance anode for lithium-ion batteries.