MOF-derived vertically stacked Mn2O3@C flakes for fiber-shaped zinc-ion batteries

Manganese (Mn)-based compounds including Mn2O3 and MnO2 have been considered promising cathode materials for aqueous zinc-ion batteries (ZIBs) due to their higher energy density, low reaction potential, and low cost. However, they intrinsically suffer from low electrical conductivity and rate capability, which largely impede their further development. Herein, we report the fabrication of a new type of 3D vertically stacked Mn2O3@C flake derived from an array of Mn-based metal-organic-framework (MOF) sheets (Mn-MIL-100) for fiber-shaped ZIBs. The fiber-shaped ZIBs made from the 3D vertically stacked Mn2O3@C flakes exhibit a high reversible volumetric capacity of 154.9 mA h cm(-3), a high energy density of 30.1 mW h cm(-3), and good cyclability (decreasing to 79.6% of the initial capacity after 3000 cycles). Due to their structural properties, the fiber-shaped ZIBs can be easily connected in series or in parallel to further offer a higher level of output voltage and energy density. This work not only broadens the horizons of cathode material design, but will also be of practical benefit in the development of wearable power sources.