Microfluidic-oriented assembly of Mn3O4@C/GFF cathode with multiscale synergistic structure for high-performance aqueous zinc-ion batteries

The electrochemical activity and long-term stability of cathodic materials, as well as active ion transport, are key factors for efficient energy storage in aqueous zinc-ion batteries (ZIBs). Here, a freestanding Mn3O4@C nanowire-implanted graphene-based fiber fabric (Mn3O4@C/GFF) cathode with a multiscale synergistic structure was fabricated using a facile microfluidic assembly method. In this architecture, Mn3O4 nanowires are hosted by a conductive carbon layer and then anchored in the interlayer of a self-assembled graphene-based fiber framework. The hierarchical structure enhances electrical conductivity and relieves ion leaching, thereby boosting the electrochemical activity and long-term stability of cathodic materials. Furthermore, the layer-by-layer assembled structure of the Mn3O4@C/GFF cathode provides ample available channels for active ion transport, accelerating the electrochemical kinetics. Consequently, the Mn3O4@C/GFF cathode exhibits enhanced electrochemical performance with a high capacity of 374.8 mAh g−1 at 0.2 A g−1 and ultralong cycle life (158.7 mAh g−1 retained over 5000 cycles at 2 A g−1). Therefore, this study provides a multiscale synergistic strategy for fabricating advanced cathodes for high-performance ZIBs.