Ezra Morris

Characterization of conducting cellulose acetate based polymer electrolytes doped with “green” ionic mixture

Polymer electrolytes were developed by solution casting technique utilizing the materials of cellulose acetate (CA), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and deep eutectic solvent (DES). The DES is synthesized from the mixture of choline chloride and urea of 1:2 ratios. The increasing DES content well plasticizes the CA:LiTFSI:DES matrix and gradually improves the ionic conductivity and chemical integrity. The highest conducting sample was identified for the composition of CA:LiTFSI:DES (28 wt.%:12 wt.%:60 wt.%), which has the greatest ability to retain the room temperature ionic conductivity over the entire 30 days of storage time. The changes in FTIR cage peaks upon varying the DES content in CA:LiTFSI:DES prove the complexation. This complexation results in the collapse of CA matrix crystallinity, observed from the reduced intensity of XRD diffraction peaks. The DES-plasticized sample is found to be more heat-stable compared to pure CA. Nevertheless, the addition of DES diminishes the CA:LiTFSI matrixs heat-resistivity but at the minimum addition the thermal stability is enhanced.

Novel Fuzzy Controlled Energy Storage for Low-Voltage Distribution Networks with Photovoltaic Systems under Highly Cloudy Conditions

AbstractThe amount of small-scaled renewable energy sources is anticipated to increase on the low-voltage distribution networks for the improvement of energy security and reduction of greenhouse gas emission. Malaysia has a high solar irradiance level that is ideal for photovoltaic (PV) systems. However, the growth of the PV systems on the low-voltage distribution networks can create a number of technical issues such as voltage rise, voltage unbalance, and reversed power flow. Usually, these issues happen with little fluctuations. However, these issues tend to fluctuate very rapidly in Malaysia because this region has a very low clear sky index. A large amount of clouds often passes over the country, hence making the incident solar irradiance to be highly scattered and fluctuating. Therefore, the power output of the PV systems fluctuates substantially. To ensure an effective operation of the distribution networks with the PV systems, a novel fuzzy control method is developed and implemented to govern the ...

Characterization of High Molecular Weight Poly(vinyl chloride) - Lithium Tetraborate Electrolyte Plasticized by Propylene Carbonate

An electrolyte is a substance consisting of free ions and acts as a medium channel for transferring the charges between a pair of electrodes. Sometimes, they are also referred as “lytes” which is derived from the Greek word, “lytos”, which means “it may be dissolved”. Electrolyte is comprised of positively charged species which is called as cation and negatively charged species, anion. The properties of an electrolyte can be exploited via electrolysis process: separation of chemically bonded element or compounds by applying the electrical current. In the early stage, liquid electrolytes have been discovered and investigated. Liquid electrolyte is a substance that conducts the electricity in an aqueous solution by migrating both cations and anions to the opposite electrodes through an electrically conducting path as a useful electric current. However, it faces problem of leakage of hazardous liquids or gases. Other drawbacks are formation of lithium dendrite, electrolytic degradation of electrolyte and uses of flammable organic solvent (Ramesh et al., 2011a). Apart from that, it exhibits poor long–term stability due to the evaporation of the liquid phase in the cells (Yang et al., 2008). Therefore, solid polymer electrolytes (SPEs) were synthesized to prevail over the limitations of conventional liquid electrolytes.

Utilisation of corn starch in production of 'green' polymer electrolytes

Abstract ‘Green’ polymer electrolytes were fabricated from corn starch (CS), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 1-allyl-3-methylimidazolium chloride, [Amim] Cl by solution casting method. This communication covers the influence of different proportions of [Amim] Cl concentration in plasticising the CS∶LiTFSI matrix in term of the degree of co-ordination, ionic conductivity and relative viscosity. The possible dipole–dipole interaction between the chemical constituents was confirmed based on the Fourier transform infrared analysis. The highest ionic conductivity of 4·18×10−4 S m−1 was achieved at room temperature for the composition of CS∶LiTFSI∶[Amim] Cl (14 wt-%∶6 wt-%∶80 wt-%). The incorporation of environmental-friendly [Amim] Cl in the polymer electrolyte is significantly important in improving the ionic conductivity by increasing the amorphous morphology that consequently improves the ion transport mechanism. The highest conducting sample possesses the lowest relative viscosity with the value of 3·98 attributed to the greater structural disorderliness.

Distributed Energy Storage Systems with an Improved Fuzzy Controller for Mitigating Voltage Unbalance on Low-Voltage Networks

AbstractThe growth of photovoltaic (PV) systems on low-voltage distribution networks can create technical issues such as voltage rise, voltage unbalance, unnecessary neutral current circulation, and reverse power flow. Usually, these happen with little fluctuation. However, they tend to fluctuate seriously because of the low clear sky index in Malaysia and they become more severe when the installation and distribution of single-phase renewable energy sources are rather arbitrary and not monitored by utility companies. To ensure effective operation of distribution networks with PV systems, an improved version of a three-phase fuzzy control algorithm for distributed energy storage (ES) systems is proposed. With this algorithm, distributed energy storage systems can control individual phase voltage to mitigate the voltage unbalance factor effectively, maintaining voltage magnitude without cutting any excess renewable energy. An experimental low-voltage distribution network with two 3.6-kWp PV systems was set...

Fuzzy-driven energy storage system for mitigating voltage unbalance factor on distribution network with photovoltaic system

The amount of small-scaled renewable energy sources is anticipated to increase on the low-voltage distribution networks for the improvement of energy efficiency and reduction of greenhouse gas emission. The growth of the PV systems on the low-voltage distribution networks can create voltage unbalance, voltage rise, and reverse-power flow. Usually these issues happen with little fluctuation. However, it tends to fluctuate severely as Malaysia is a region with low clear sky index. A large amount of clouds often passes over the country, hence making the solar irradiance to be highly scattered. Therefore, the PV power output fluctuates substantially. These issues can lead to the malfunction of the electronic based equipment, reduction in the network efficiency and improper operation of the power protection system. At the current practice, the amount of PV system installed on the distribution network is constraint by the utility company. As a result, this can limit the reduction of carbon footprint. Therefore,...

Investigation on the Morphology of Sintered Silver Nanomaterial for Electronic Packaging Application

Silver nanoparticles are seen as a possible replacement for high temperature solders containing 90-95 wt.% Pb, which is widely used in various applications e.g. automotives. These high temperature solders have been exempted from the Restriction of Hazardous Substances (RoHS) Directive due to very limited drop-in replacement for the high temperature solders. Although the effect of sintering temperature of silver nanoparticles has been studied, the mechanism involved in the changes in the morphology of the particles and interfacial reaction with the substrate as a function of sintering temperature must be understood. In this study the effect of sintering temperature on the morpohology of Ag nanoparticles is discussed. The Scanning Electron Microscopy (SEM) analysis was used to analyze the changes in morphology of silver particles agglomerates with sintering temperatures. Results showed necking of the nanosilver powder, which indicated the occurrence of sintering through grain boundary diffusion process. Meanwhile, the micro-silver powder showed agglomeration of particles but no necking was observed. The study has shown that the Ag agglomerates was observed to undergo various changes to the particle morphology with different sintering temperatures.