Ag_xMn₈O₁₆Cathode Enables High-Performance Aqueous Li-Ion Hybrid Supercapacitors

As an energy storage device with high energy density and power density simultaneously, hybrid supercapacitors (HSCs) have attracted more and more attention. The electrochemical performance of electrode material has a decisive effect on hybrid devices. To develop excellent faradaic electrode material for aqueous hybrid Li-ion HSCs, the silver ion pre-embedded manganese oxide materials (marked as AMO) are successfully synthesized by a high-temperature solid-phase method. In comparison to MnO₂, the specific capacitance of AMO-400 is greatly improved from 246.0 to 326.1 F g^-1at 0.5 mV s^-1. When matched with activated carbon to assemble the Li-ion HSCs with the widened voltage window of 0-2.1 V, the highest power density of 3211.0 W kg^-1and energy density of 111.0 Wh kg^-1are obtained.