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

Cations preintercalation is an effective way to optimize the crystal structure and improve the electrochemical behavior. An Ag pre-intercalated Ag 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 electrolyte and 450.1 F g system are achieved. The assembled HSCs using Ag 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- for Li-ion HSCs and 131.08 Wh kg- at 107.25 W kg- 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.

Automated summary

Cation preintercalation can optimize crystal structure and improve the electrochemical behavior, as demonstrated by the Ag pre-intercalated material prepared in this study. The HSCs assembled using Ag and activated carbon show a high specific capacitance, wide operation potential window, and excellent cyclic stability, making them promising for energy storage applications.