Ag+ preintercalation enabling high performance AgxMnO2 cathode for aqueous Li-ion and Na-ion hybrid supercapacitors

Abstract Cations preintercalation is an effective way to optimize the crystal structure and improve the electrochemical behavior. An Ag+ pre-intercalated AgxMnO2 material with ultrafine nanowire structure is prepared by a facile hydrothermal method. With optimized crystalline microstructure including expanded interlayer space and introduced multivalence of Mn, the as-prepared material exhibits superior performance as cathode for both Li-ion and Na-ion hybrid supercapacitors (HSCs). High specific capacitance of 424.7 F g−1 in Li2SO4 electrolyte and 450.1 F g−1 in Na2SO4 system are achieved. The assembled HSCs using AgxMnO2 and activated carbon (YEC-8A) as electrode materials deliver a wide operation potential window of 0–2.2 V and a high energy density of 204.30 Wh kg−1 at the power density of 167.15 W kg−1 for Li-ion HSCs and 131.08 Wh kg−1 at 107.25 W kg−1 for Na-ion HSCs. Furthermore, the as-fabricated HSCs deliver excellent cyclic stability. The capacitance retention is 79.4% after 20,000 cycles for Li-ion HSC and 84.9% after 10,000 cycles for Na-ion HCS.