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Metal sulfide-based composites have become increasingly common as materials used for electrodes in supercapacitors because of their excellent conductivity, electrochemical activity, and redox capacity. This study synthesized a composite of NiFeS@MoS2@rGO nanostructure using a simple hydrothermal approach. The synthesized nanocomposite consisted of the composite of nickel sulfide and iron sulfide doped with MoS2@rGO. A three-electrode cell is employed to investigate the electrochemical properties of the NiFeS@MoS2@rGO electrode. The results demonstrated an optimal specific capacitance of 3188 F/g at 1.4 A/g in a 1 M KOH electrolyte. Furthermore, a supercapattery is designed utilizing NiFeS@MoS2@rGO//AC as the positive electrode and activated carbon (AC) as the negative electrode materials. The resulting supercapattery is designed at a cell voltage of 1.6 V, achieving a specific capacity value of 189 C/g at 1.4 A/g. It also demonstrated an excellent energy density of 55 Wh/kg with an enhanced power density of 3800 W/kg. Furthermore, the hybrid device demonstrated remarkable stability with a cycling stability of 95% over 30,000 charge–discharge cycles at a current density of 1.4 A/g. The supercapattery, which has excellent energy storage capabilities, is used as a power source for operating different portable electronic devices. [ABSTRACT FROM AUTHOR]

Supercapattery is an energy storage device which shows high power and energy densities compared to supercapacitors and batteries. A simple and cost‐effective sol‐gel method was used to synthesize the aluminium‐doped cobalt oxide (Al‐Co3O4). The structural, morphological and composition analyses were investigated using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and X‐ray photoelectron spectroscopy (XPS). Further, Brunauer‐Emmett‐Teller (BET) calculations were performed, which showed an enhancement in surface area. The specific capacity of the Al‐doped sample was increased up to 708 C/g compared to the reference sample (Co3O4=420 C/g). A supercapattery device was designed by using the activated carbon as a negative electrode and the Al‐Co3O4 as the positive electrode in two electrode assemblies. The estimated value of the specific capacity of Al‐Co3O4 was 189 C/g. Furthermore, the obtained energy and power density values were 42 Wh/kg and 2080 W/kg, respectively. To investigate the stability, this device was subjected to 5000 charging/discharging cycles that maintained 90 % of its initial capacity. Our findings provide a foundation for improving the performance of energy storage devices. [ABSTRACT FROM AUTHOR]

Supercapattery combines the properties of supercapacitors and batteries and has excellent energy and power densities. It has gotten much attention as compared to supercapacitors and batteries because of its high energy storage capability and stability. To design a supercapattery device, the strontium phosphate, copper phosphate, and their three composites with different weight ratios such as Sr0.75 Cu0.25 PO4, Sr0.5.0, Cu0.50PO4, and Sr0.25 Cu0.75 PO4 and named as S1, S2, and S3 were synthesized using a hydrothermal approach. X-ray diffraction and scanning electron microscopy to examine the structural characterization as well as the surface morphology of all the samples. More specific capacity was calculated for all the samples, and found that the specific capacity having its maximum value of 856 C/g at 2.0 A/g was attributed to S1 sample due to the overall effect of strontium with copper. The hybrid device S2 was also prepared using activated carbon which is considered a positive electrode, while S2 worked as a negative electrode. SrCuPo4 has an estimated power density of 793.92 W/Kg, the energy density is 31.4 Wh/Kg. A reliability measurement was performed on this real device for assessing stability, and after 1000 charging/discharging cycles, it was observed that 87 percent of the initial capacity was retained. Thus strontium copper phosphate can help us in the future for industrial applications of supercapattery for high energy density and power density. [ABSTRACT FROM AUTHOR]

Summary: A supercapattery is a device that combines the benefits of supercapacitors' superior power density and cycle stability with the advantages of batteries' higher energy density. We used a simple hydrothermal method to synthesize nickel sulfide (NiS), silver sulfide (Ag2S), and nickel silver sulfide (NiAg2S). The NiS and Ag2S were combined in the best 50/50 weight ratio and found that the specific capacity for NiAg2S is 571.2 C/g which is higher as compared to individual NiS and Ag2S 305.2 C/g and 364 C/g, respectively. Even at 2 A/g, more than 69% of the specific capacity is retained. For asymmetric device fabrication (NiAg2S//AC), the activated carbon was selected as a negative electrode, while NiAg2S was chosen as a positive electrode. A specific capacity of 130.4 C/g was achieved with this device. Energy density for NiAg2S was observed to be 28.97 Wh/kg having a power density of 640 W/kg. To investigate stability, a durability test was performed by subjecting this device to 1000 charging/discharging cycles, which maintain 86% of the initial capacity. Our findings suggest that a mixture of nickel and silver sulfide having a 50/50 weight ratio functioning as an electrode material for supercapattery applications may be more appropriate. [ABSTRACT FROM AUTHOR]