Synthesis of ultralong ZnFe2O4@polypyrrole nanowires with enhanced electrochemical Li-storage behaviors for lithium-ion batteries

Spinel ZnFe2O4 (ZFO) has been emerging as promising anode material for lithium-ion batteries (LIBs) due to its intrinsic merits. However, inferior electrical conductivity and severe volume change hinder its practical applications. Herein, we developed a bottom-up electrospinning and gas-phase polymerization strategy for purposeful fabrication of one-dimensional (1D) nano-architecture with continuous polypyrrole (PPY) nanoshell coating on each ZFO nano-subunit throughout the whole nanowires (NWs). Benefiting from unique compositional and structural advantages, the resultant 1D hybrid product (denoted as ZFO@PPY) with large electroactive sur-/interfaces and robust structural stability displayed superior Li-storage performance with high initial Coulombic efficiency, large reversible capacities, high-rate capability and long-term cycling performance, when evaluated as a competitive anode for low-cost LIBs. Furthermore, In-situ X-ray diffraction measurement provided insights into the underlying Li-storage process of the ZFO@PPY NWs. More significantly, we strongly envision that our integrated electrode design would pave a promisingly feasible avenue for advanced hybrid anodes for advanced LIBs. 1D ultralong ZnFe2O4@polypyrrole hybrid nanowires were elegantly fabricated and displayed superior Li-storage behaviors for advanced Li-ion batteries as a competitive anode. [Display omitted] •Scalable electrospinning method along with gas-phase polymerization is developed to synthesize 1D ultralong ZFO@PPY NWs.•1D ZFO@PPY NWs are endowed with continuous PPY nanoshell coating on each ZFO subunits throughout the hybrid NWs.•The hybrid NWs exhibit short Li+ transport length, large electroactive sur-/interfaces, and superior structural stability.•The ZFO@PPY NWs display large reversible and stable capacities, and high initial Columbic efficiency at high rates.