Supercapacitors with nanostructured activated carbon electrodes from natural precursors have sparked huge attention due to its great stability of cycle as well as low cost and excellent performance. In this study, activated carbon was produced from desiccated coconut residue by chemical activation with KOH. The supercapacitor was characterized in a supercapacitor configuration by cyclic voltammetry and charge-discharge with potential window of 1V and current loads of 1A/g. Supercapacitor electrodes prepared from desiccated coconut residue exhibited excellent specific capacitance of 83 F/g.

Activated carbon derived from desiccated coconut residue was treated with sodium hydroxide (NaOH) and analyzed for its supercapacitor performance. The sample was then characterized by N2 adsorption at -196°C, Energy dispersive x-ray (EDX) analysis and X-ray diffraction (XRD) in order to investigate its surface area, porosity and microcrystalline properties. Specific surface area (SSA) was found to be 1394.79 m2/g with high microporosity of 76.92 %. Electrochemical double-layer capacitance was studied by cyclic voltammetry with potential window of 1V. The presence of high microporosity properties affects the supercapacitor performance due to lack of accessibility of the electrolyte into the activated carbon pores. The calculated specific capacitance was found to be 42 F/g.

An electrochemical symmetric capacitor with a modest energy and power densities has been fabricated using a commercially prepared carbon nanotubes as electrode and hybrid solid polymer electrolyte. This integrated separator and electrolyte layer is made up of a filter paper, a polyvinyl alcohol (PVA) doped with phosphoric acid at three different concentrations. The electrode material consisted of 90 % of the said carbon nanotubes and 10 % of Poly (Vinylidene Fluoride-Co-Hexafluoropropylene) (PVdF-HFP). Three cells were then assembled as follows; cell-A (N90PVdF-HFP10 |H50| N90PVdF-HFP10), cell-B (N90PVdF-HFP10 |H60| N90PVdF-HFP10) and cell-C (N90PVdF-HFP10 |H70| N90PVdF-HFP10). These as-assembled symmetric supercapacitor with an optimal mass ratio was able to be operated reversibly over a wide voltage range of 0.0–3.0 V, depending on the cell-type. Overall, the supercapacitor fabricated from cell A exhibits excellent rate capability with a capacitance, energy and power densities of 163.66 Fg?1, 822.00 Jg?1 and 5.38 Jg?1s?1 respectively, and long-term cycling stability of 5000 cycles.

This paper discusses the numerical solution of the 1-dimensional Schrödinger equation using method of lines approach (MOL) where the spatial dimension is discretize using some finite difference approximation leaving the time dimension to be the only independent variable in the resulting system of initial value problems. The effect of changing the discretization size on the stability of the solution procedure with respect to the absolute stability property of the numerical method used has been studied. In the study the use of Simpson’s rule in MATLAB has also been incorporated. The result indicates that there is some relationship between the discretization size and the convergence property. Further work will look into the modeling this equation to the application in Physics.

The nobility of solid polymer electrolyte (SPEs) has made them a subject of interest, especially in the arena of science and technology, and most importantly as they are used as separators in industries and by researchers for the assembly of some “few battery types” and supercapacitors. This paper, highlights the nobility of the hybrid solid polymer electrolyte (HSPE), particularly at room temperature such that, it can be used as an electrolyte as well as a separator in supercapacitor fabrication. The hybrid SPEs were produced from the composition of polyvinyl alcohol (PVA) and Phosphoric acid (H3PO4), where the PVA samples were kept constant while the phosphoric acid concentration was varied at 0, 10, 20, 30, 40, 50, 60, and 70 wt. %. XRD results show that, the crystallinity decreases as the acid concentration increases and consequently, there is an enhancement in the amorphicity of the samples responsible for the process of ion transport. This characteristic behavior was confirmed by the analysis of the differential scanning calorimetry results. FESEM result pictured the entangling nature of the combined samples. High conductivity of 1.67 x 10-3. Scm-1 was recorded for the HSPE at the composition of 70:30 wt. %. It was also noticed that, the bulk modulus, Rb of the HSPE (5.73 ?) at the aforementioned composition decreases with the increase in concentration.

This study investigates the effect of temperature and impregnation ratio on the physicochemical properties of activated carbon prepared from agricultural waste; desiccated coconut residue (DCR) by chemical activation using sodium hydroxide (NaOH). DCR sample was first carbonized at three different temperatures for 1 hour at 400°C, 500°C, and 600°C respectively. The resulting chars were impregnated with NaOH at three different impregnation ratio; 1:1, 1:2, and 1:3 respectively and activated under nitrogen atmosphere for 1 hour at three different temperatures based on its carbonization temperature. The specific surface area was strongly affected by impregnation ratio in which increased with impregnation ratio. The specific surface area also increased with temperature but then decreased at highest desired temperature.

A separator is prepared from the resulting mixture of hybrid polymer electrolyte polyvinyl alcohol (PVA) (70%) and Phosphoric acid (H3PO4) (30%) immersed in the solution of the combination of polymethyl (methacrylate) and lauroyl chitosan (PLC), for supercapacitor application. The Electrochemical Impedance Spectroscopy (EIS) was conducted twice at normal temperature in an interval of Seven days with very high electrical conductivity of to be 6.42 × 10-4 S cm-1 and 1.84 × 10-4 S cm-1 within these intervals respectively and very low resistance. The supercapacitor was then fabricated using a Commercially Prepared Multi-walled Carbon Nanotube (CPMWCNT) which was sized to an area of 3.5 cm2 and assembled in an innovative supercapacitor tester. The result indicates a relatively high efficiency of about 90% and also exhibited long and excellent cycleability of life time (>1000 cycles) under different voltage windows.

A separator is prepared from the resulting mixture of hybrid polymer electrolyte polyvinyl alcohol (PVA) (70%) and Phosphoric acid (H3PO4) (30%) immersed in the solution of the combination of polymethyl (methacrylate) and lauroyl chitosan (PLC), for supercapacitor application. The Electrochemical Impedance Spectroscopy (EIS) was conducted twice at normal temperature in an interval of Seven days with very high electrical conductivity of to be 6.42 × 10-4 S cm-1 and 1.84 × 10-4 S cm-1 within these intervals respectively and very low resistance. The supercapacitor was then fabricated using a Commercially Prepared Multi-walled Carbon Nanotube (CPMWCNT) which was sized to an area of 3.5 cm2 and assembled in an innovative supercapacitor tester. The result indicates a relatively high efficiency of about 90% and also exhibited long and excellent cycleability of life time (>1000 cycles) under different voltage windows.