Binder-free stainless steel@Mn3O4 nanoflower composite: a high-activity aqueous zinc-ion battery cathode with high-capacity and long-cycle-life

Rechargeable aqueous zinc-ion batteries (ZIBs) are highly desirable for large-scale energy storage to meet the increasing demand for safe and sustainable energy storage devices. Herein, we report a binder-free stainless steel welded mesh@flower-like Mn3O4 (SSWM@Mn3O4) composite with high zinc storage capability for aqueous ZIBs. Chemical conversion reaction mechanism is proposed for this material. The hierarchical nanoflower structure composed of ultrathin nanosheets facilitates electrolytic infiltration and diffusion of Zn2+. Benefiting from the binder-free conductive substrate, SSWM@Mn3O4 exhibits lower electrode reaction resistance and smaller slope of Warburg diffusion element, which contributes to the excellent electrochemical performances, including high specific capacity of 296 mA h g(-1) at 100 mA g(-1) and long-term cyclic stability up to 500 cycles at 500 mA g(-1), thus demonstrating a promising cathode for aqueous ZIBs.