Solid polymer electrolyte based on methyl cellulose (MC)-lithium triflate (LiCF3SO3) plasticised with ethylene carbonate (EC) was prepared using solution cast technique. The X-ray diffraction (XRD) studies proved that the amorphous nature of the electrolyte systems was increases due to the addition of salt and plasticiser. The improved surface morphology of plasticised polymer system ensures it has good electrode-electrolyte contact during performance testing. The polymer electrolyte was found to have high thermal stability indicating that the electrolyte can be used at higher temperature. The ionic conductivity increased up to 1.24 x 10-4 S cm-1 at optimum amount of EC plasticiser associated to the effect of plasticiser that initially leads to the formation of Li+-EC complex. Consequently, it reduces the fraction of polymer-Li+ complex which contributes to the increase of the segmental chain flexibility in the plasticized system. Temperature dependent studies indicate ionic conductivity increase due to the temperature increase and is in line with Arrhenius behaviour pattern. An activation energy of 0.26 eV at highest conductivity sample was obtained. The addition of plasticiser lowers the activation energy thus increasing the ion mobility of the system and contributing to ionic conductivity increment. The plasticization method is a promising means to dealing with the solid polymer electrolyte problem and producing electrolytes that meet the needs of electrochemical devices.
This study investigates the effect of oxalic acid at different concentrations as doping agent on
the electrical properties of polyaniline (PANI). The polymerization of aniline to produce
PANI was carried out in media containing oxalic acid at 0.08 M, 0.09 M, 0.1 M, 0.2 M and
0.3 M in the presence of ammonium persulphate as oxidizing agent. The successful formation
of PANI doped with oxalic acid was confirmed by FTIR and the morphology studied using
XRD. An impedance investigation on the series of PANI formed revealed that doping in 0.1M
oxalic acid produced PANI of the highest conductivity of 2.52 x 10-6
Scm-1.
Many kinds of substrates have been used to investigate bioelectricity production with Microbial Fuel Cell (MFC). Dry algae biomass has the highest maximum power density compared to other substrates due to high carbon sources from its lipid. However, the bacterial digestion of algae biomass is not simple because of the complexity and strength of the algal cell wall structure. An algae biomass extraction is needed to break the cell wall structure and facilitate digestion. Spray drying method is commonly used in highvalue products but may degrade some algal components which are crucial for microbial degradation in MFC, while the freeze-drying method is able to preserve algal cell constituents. The MFC was fed with freeze dried and spray dried algae biomass to produce energy and determine the degradation efficiency. Results showed the average voltage generated was 739 mV and 740 mV from freeze dried and spray dried algae biomass, respectively. The maximum power density of freeze dried algae biomass is 159.9 mW/m2 and spray dried algae biomass is 152.3 mW/m2. Freeze dried algae biomass has 54.2% of COD removal and 28.4% of Coulombic Efficiency while spray dried algae biomass has 50.1% of COD removal and 24.9% of Coulombic Efficiency.