Rationally designed metal–organic framework templated iron-molybdenum sulfide for high energy density hybrid supercapacitors

The rational design of high-performance electrodes is of major significance for the fabrication of advanced energy storage technologies. Herein, surface engineering has been extensively implemented to obtain nonprecious metal organic frameworks (MOFs) as a template, to carry out in-situ growth of iron molybdenum sulfide on nickel foam (denoted as Fe-MoS₂@NF). The novel architecture of the synthesized electrode demonstrates a high-performance supercapacitor. Fe-MoS₂@NF electrode delivers a high areal capacity of 3565 mC cm⁻² at a current density of 4 mA cm⁻² in 6 M KOH aqueous electrolyte and retains 89 % of areal capacity after 5000 cycles. In addition, a hybrid supercapacitor (HSC) was fabricated comprising the Fe-MoS₂@NF and O, N, S@AC as positive and negative electrodes, respectively. The fabricated HSC exhibits a high specific capacity of 60 mAh g⁻¹ at 1 A g⁻¹ and delivers an excellent specific energy of 49.4 Wh kg⁻¹ corresponding to a specific power of 827 W kg⁻¹ and maintains the specific energy of 10.2 Wh kg⁻¹ at a high specific power of 13.42 kW kg⁻¹. Moreover, the device showed a better cyclic stability ∼ 91 % for 10,000 charge/discharge cycles. Thus, the design concept of the electrode opens a new avenue towards the battery type supercapacitor applications.