We report a novel configuration of symmetrical electric double-layer capacitors (EDLCs) comprising a plastic crystalline succinonitrile (SN) based flexible polymer gel electrolyte, incorporated with sodium trifluoromethane sulfonate (NaTf) immobilised in a host polymer poly (vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP). The cost-effective activated carbon powder possessing a specific surface area (SSA) of similar to 1700 m(2)g(-1) containing a large proportion of meso-porosity has been derived from tea waste to use as supercapacitor electrodes. The high ionic conductivity (similar to 3.6x10(-3) S cm(-1) at room temperature) and good electrochemical stability render the gel polymer electrolyte film a suitable candidate for the fabrication of EDLCs. The performance of the EDLCs has been tested by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge-discharge studies. The performance of the EDLC cell is found to be promising in terms of high values of specific capacitance (similar to 270 F g(-1)), specific energy (similar to 36 Wh kg(-1)), and power density (similar to 33 kW kg(-1)).

Graphene/semicrystalline-carbon in the form of carbon flakes is produced by carbonization up to 600, 700, 800, 900 and 1000 degrees C, respectively, of the amylose films prepared by a casting method on copper foil substrate. The carbon flakes are characterized by X-ray diffraction (XRD) method to determine their microcrystallite interlayer spacing, width and stack-height; and Raman spectroscopy (RS) method to obtain structural information from the D-, D2- and G-bands peak-intensities. The XRD results show that increase in carbonization temperature lead to similar to(1-3 %), similar to 85 % and similar to 30 % increase in the microcrystallites interlayer spacing, width and stack-height, respectively, indicating that a larger growth of microcrytallite of carbon flakes occurs in the direction parallel to (001) plane or film planar surface. The specific surface area of carbon flakes estimated from the XRD results in decreases from similar to 4400 to similar to 3400 m(2)/g, corresponding to the specific capacitance between similar to 500 to similar to 400 F/g, which are well within the range of specific capacitance for typical electrodes carbon for supercapacitor application. The RS results show that the multilayer graphene co-exist with semicrystalline-carbon within the carbon flakes, with the multilayer graphene relative quantities increase with increasing carbonization temperature.

A good thermoelectric material is known to have a high value of dimensionless figure-of-merit (ZT). Determination of ZT has been proposed in many ways either using analytical or experimental approach where ZT measure experimentally can be obtained directly or indirectly. Although measuring ZT directly will give quick and reliable results, the measurement has lack in accuracy compared to indirect measurement technique. By having many research on improving the thermoelectric materials performance, quick, easy and reliable technique to determine its performance is one of the of the important factors. Not many techniques can give direct ZT value especially at high temperature difference for thermoelectric generators application. Generally ZT is measured under small temperature difference in each of homogeneous single leg thus does not suitable for segmented leg which is useful in higher operation of temperature range. This review paper focused on research had been done relating to the technique available to measure ZT at macroscale level. It is reveals the possibilities of ZT measurement at large temperature difference and under operational condition. This is important as progress in materials requires easy and reliable method to determine performance at real condition of thermoelectric operation.

The growth of Sn:ZnO nanowires on a silicon substrate using a low thermal evaporation method is reported. A horizontal quartz tube with controlled supply of O-2 gas were used to fabricate the samples where Zn and Sn metal powders were previously mixed and heated at 500 degrees C. This allows the reactant vapours to deposit onto the substrate, which placed at a certain distance from the source materials. The samples were characterized using FESEM, EDX and HRTEM measurements. Randomly oriented nanowires were formed with varying dopant concentrations from 3 to 15 at%. It was observed that from FESEM images, when the dopant concentrations were increased, a hexagonal rod with a wire extended at its end was clearly formed and the best images of nanowires were shown at the highest concentration of 15 at% measuring between 26 to 35 nm and roughly 500 nm in diameter and length respectively. The doping process played an important role in order to alter the morphological properties of Sn: ZnO nanowires. Sn: ZnO nanowires have large potential in many applications such as in selected sensor technology including gaseous sensors, liquid sensors and others.

The main objective of the present work is to develop a high conducting hybrid solid polymer electrolyte (HSPE) using polyvinyl alcohol as the host polymer and H(3)PO(4) as the ionic dopant. Owing to its porous nature, the introduction of a Whatman filter paper helps to increase the electrical conductivity by acting as a support to the electrolyte system. This allows more H(3)PO(4) acid to be loaded into the system and thus helps to improve the mechanical strength of the electrolytes. The highest conducting HSPE was obtained at 1.04 x 10(-4) S cm(-1) for samples containing 70% loading of acid (P30H70-C). Such conductivity is sufficient for application in an electrical double layer capacitor (EDLC). The EDLC was fabricated using the hybrid electrolyte with its activated carbon electrodes soaked in H(3)PO(4). A specific capacitance of 34 F g(-1) with internal resistance of as low as 1 Omega cm(-2) was obtained when the cell was charged-discharged at 10 mA. The working voltage for this EDLC is 1 V with efficiency ranging between 85 and 97%.

Binderless electrodes of activated carbon monoliths (ACMs) and its composites with graphene are prepared by carbonization and activation of green monoliths consisting of self-adhesive carbon grains and 0-10 wt% KOH-treated graphene. Compared with ACMs, the optimized composite containing 6 wt% graphene exhibits more ordered micro-structures with increased crystallite height, and graphitic sp(2) carbons (I (D) /I (G) = 0.49 vs. 0.91) along with enhanced porosity; as revealed by X-ray diffraction, Raman, and N-2 adsorption-desorption studies. These modifications lead to increased electrical conductivity (13 vs. 9 S cm(-1)) through improved interconnections of carbon particles by graphene, and surface area similar to (800 vs. 456 m(2) g(-1)) due to increased inter-particle spacing. Further, contrary to ACMs, the composite electrodes can offer faster delivery of energy in almost 50% less response time (5 vs. 8 s) due to reduced equivalent series resistance (1.67 vs. 2.65 Omega) and charge transfer resistance (0.55 vs. 1.33 Omega).