Superior supercapattery performance enabled by MnS/Fe₂O₃ nanosheets and theoretical evaluation of contributing currents

Supercapattery has attracted significant attention for its exceptional energy storage capabilities. These devices provide far higher energy and power densities than supercapacitors and batteries. Herein, we investigate the novel MnS/Fe₂O₃ nanosheets (NS), synthesized by rapid, low cost and facile co-precipitation approach for supercapattery applications. A detailed structural, morphological and electrochemical analysis of synthesized materials, have been carried out. Benefiting from the enhanced surface area, MnS/Fe₂O₃ NS exhibits higher energy density of 90 Wh kg⁻¹ at power density of 5800 W kg⁻¹, as well superior specific capacitance of 950 F g⁻¹ as compared to the pristine MnS (470 F g⁻¹) with in potential window of −0.2 to 0.75 V. The initial characterization of synthesized material anticipates the battery type nature which was verified via theoretical Dunn's differentiation approach. Due to the superior electrochemical performance, the electrode was further considered for supercapattery applications. A full cell supercapattery is fabricated by MnS/Fe₂O₃ NS as anode and reduce graphene oxide (rGO) as cathode which shows higher specific capacitance of 220 F g⁻¹ at 1 A g⁻¹ current density, demonstrating higher energy density 120 Wh kg⁻¹ and power density of 6050 W kg⁻¹. The device also exhibits outstanding capacitance retention (90 %) and coulombic efficiency (95 %) at 20 A g⁻¹ over 3000 cycles.