Fe_3O_4/graphene-oxide/chitosan hybrid aerogel based high performance supercapacitor: effect of aqueous electrolytes on storage capacity cell stability

摘要

In this work, Fe3O4/graphene-oxide/chitosan aerogel (GCFA) with 3-D interconnected structure (average pore size -8.4 nm) and moderate BET surface area (-59 m(2)/g) is synthesized by hydrothermal route. Three different hybrid symmetric supercapacitor cells are fabricated using GCFA as active electrode material, using basic (6M KOH: cell-1), acidic (1M H2SO4: cell-2), neutral (Na2SO4: cell-3) as electrolyte mediums. Subsequently, a comprehensive study is carried out to assess the effect of electrolyte on the porous architecture, charge storage capacity, rate capability and cyclic stability. Besides, cell-3 also shows good cyclic stability with low initial fading (-15), good capacity retention (-84) It has been observed that cell-3 displayed better performance (specific capacitance-160 F g(-1), specific energy-14.6 Wh kg(-1) and specific power-0.77 kW kg(-1)) than either of cell-2 (-160 F g(-1),-7.84 Wh kg(-1) nbsp;and-0.45 kW kg-1) or cell-1 (-102 F g(-1),-1.54 Wh kg(-1) nbsp;and-0.14 kW kg(-1)) and excellent coulombic efficiency (-91) even after 10,000 charge-discharge cycles. This is attributed to the better pore accessibility, stability of residual surface functionalities under potential cycling, and least screening for intra-pore shuttling of counter-ions under neutral medium.