Synthesis of a novel magnetite/nitrogen-doped reduced graphene oxide nanocomposite as high performance supercapacitor

Newly Design Porous/Sponge Red Phosphorus@Graphene and Highly Conductive Ni2P Electrode for Asymmetric Solid State Supercapacitive Device With Excellent Performance

“…6 c, which shows that the highest capacitance (294 F g −1 ) was observed at 1.5 A g −1 , and at 2.5, 4, 5, 7, and 10 A g −1 , capacitance values of 225, 200, 150, 147, and 120 F g −1 were observed, respectively. Additionally, the calculated specific capacitance of the rP@rGO electrode was higher than those reported in the previous studies [ 19 , 21 , 28 ]. Apart from CV and CD measurements, the cyclic stability of the rP@rGO electrode was also measured during consecutive 4500 charge/discharge cycles at a current density of 5 A g −1 .…”

“…The basic spectroscopic and microscopic characteristics of this electrode, as well as its individual electrochemical performance, were studied in detail, before the asymmetric solid-state device was assembled. At 1.5 A g −1 , this negative electrode showed a capacitance of 294 F g −1 , which is approximately higher than those of other electrodes that have reported in the previous studies [ 19 , 21 ]. Additionally, without using any surfactant, a positive electrode (Ni 2 P) was developed using simple steps, considering the abundance of its precursor, red phosphorus (rP).…”

“…To obtain high energy and power densities, the development of negative carbonaceous electrodes is also important [ 19 , 21 ]. Various types of materials have been targeted for developing negative electrodes for use in hybrid supercapacitor devices; e.g., owing to their high power density, large surface area, and long life cycle, carbon- (CNT, AC) and graphene-based materials have been extensively employed as the most preferred electrode materials for electric double-layer capacitors (EDLC) [ 18 , 19 , 22 ].…”

“…However, like its composite materials, it has not yet been used as the negative electrode in asymmetric supercapacitors. Hence, its application in this context might open a new window for the development of advanced negative electrodes in the field of energy storage devices [ 21 , 26 ]. Apart from the challenges associated with the positive and negative electrodes, the use of liquid or electrolyte-based asymmetric supercapacitive devices is still an issue that affects the overall performance of the supercapacitor.…”

Toward Low-Cost and Sustainable Supercapacitor Electrode Processing: Simultaneous Carbon Grafting and Coating of Mixed-Valence Metal Oxides by Fast Annealing

“…Similar redox peaks for carbon-Fe 3 O 4 composites in the potential range of 0 to −0.5 V vs. Hg/Hg 2 Cl 2 in sodium sulfate solution have been also reported by other groups. The redox peaks are attributed to Fe II /Fe III electron transfer reaction, and as observed here, they are significantly promoted by the carbon supports such as reduced graphene oxide (Rebuttini et al, 2015; Naderi et al, 2016; Li et al, 2018) and carbon black (Sayahi et al, 2014). For Mn 3 O 4 , the redox peaks between 0.4 and 0.6 V are attributed to the reversible redox reaction between tetrahedral [Mn II O 4 ] and octahedral [Mn III O 6 ] (Yeager et al, 2013), in contrast to MnO 2 which does not show any obvious redox peaks (Wang et al, 2017).…”