Isdiriayani Nurdin

Effect of hydrogen temperature and current load on the performance of proton exchange membrane fuel cell under start-stop operation

Proton Exchange Membrane Fuel Cell (PEMFC) is one of fuel cell type that suitable for vehicular application because it has low operation pressure and temperature, stable, relatively small, and highly mobile. The major concern of PEMFC as vehicular power is its resistance toward start-stop cycle and constant load. PEMFC on vehicular application require fuel processor to produce hydrogen as fuel source. Output temperature of hydrogen from fuel processor is about 80°C, which is high enough for PEMFC. The temperature is allegedly affecting the performance of PEMFC. This research is focused on studying the effect of hydrogen feed temperature on the performance of PEMFC. Fuel cell is operated in the start-stop cycle and constant load to simulate the conditions in vehicular application. PEMFC stack has been operated with 10 start-stop cycles under constant load of 0.05 and 0.1 A/cm2 at temperatures 25, 40, 60, and 80°C. The electrochemical characterizations were carried out using chronopotentiometry and potentiodynamic polarization, while post experimental physical observations were carried out by using XRD and SEM. The experimental results show that under low constant load (0.05 A/cm2), the increase of hydrogen temperature has raised stack performance when operated with start-stop cycles, but lowered the stack performance when operated without start-stop cycle. Under high constant load (0.1 A/cm2), higher hydrogen temperature increased the stack performance, either operated with or without start-stop cycle. Post experimental XRD and SEM analysis show that the decrease of PEMFC performance is caused by platinum catalyst particles growth and MEA thickness alteration.

Effect of start-stop cycle on Direct Ethanol Fuel Cell for transportation purpose

Energy has become fundamental human needs throughout the world. One form of renewable energy as an alternative fuel is hydrogen fuel cell. Fuel cell is an electrochemical device that can convert chemical energy directly into electrical energy and heat with high efficiency and a low negative impact on the environment. Direct Ethanol Fuel Cell (DEFC) is one type of fuel cell that can utilize ethanol derived from biomass. Studies have shown that addition of sodium hydroxide is able to improve the performance of DEFC. However, the effect of pH in the fuel cell has not been studied. In addition, application of DEFC always works with start and stop cycle, which may affect its durability. This study focused on the endurance test of DEFC fueled with synthetic bioethanol influenced by start-stop cycles in various pH (6-8). Constant load of 1 and 2 mA/cm2 were given. The performance of DEFC was analyzed using electrochemical characterization methods, such as the Open Circuit Potential and Potentiodynamic. Physical characterization using Scanning Electron Microscopy (SEM). The Results shown ethanol variation pH 8 produce best power density than the others after repeated cycles on a certain constant load. The addition of sodium hydroxide push electro-oxidation reaction perfectly takes place. Degradation phenomenon occurred particularly detachment catalyst that affected performance of DEFC.

Effect of start-stop cycles and hydrogen temperature on the performance of Proton Exchange Membrane Fuel Cell (PEMFC)

Vehicular application of Proton Exchange Membrane Fuel Cells (PEMFC) poses durability and stability issues toward the multiple start-stops operation. Start-stop cycle leads to performance decay for PEMFC over time. Considering its reliability, PEMFCs performance recovery becomes a major concern. In electrical vehicle which does not used hydrogen tank due to safety, PEMFC require fuel processor to produce hydrogen as fuel source from ethanol. Output temperature of hydrogen from fuel processor is about 80°C, which is quite high for PEMFC. Temperature is alleged having an impact on the performance of PEMFC. This research is focused on studying the effect of start-stop cycle and hydrogen temperature on the performance of PEMFC under constant loads using electrochemical characterisation. The number of start-stop cycle was varied by 10, 20 and 30 cycles under constant loads of 1 and 0.5 ampere. The temperature that used for hydrogen was 40°C. The result shows that heating hydrogen to 40°C does not have significant effect to PEMFCs performance. However, enhancing start-stop cycle number has increased degradation of PEMFC stack.

SO X and NO X impurities effect on the performance of proton exchange membrane fuel cell (PEMFC) for electric vehicle application

Exposure to polluted ambient air is inevitable in vehicular application of proton exchange membrane fuel cell (PEMFC). SO₂ and NO₂ are common pollutants which in individual are known to alter PEMFC performance for their presence in the oxidant, as indicated by preceding researchers. However, interacting effects of SO₂ and NO₂ in the oxidant on PEMFC have not been extensively studied. Concerning the vehicular application of PEMFC, durability issue related with SO₂ and NO₂ - poisoned PEMFC are also necessary to be studied in order to maintain the vehicles performance. Hence this research encompasses the poisoning effects of SO₂ and NO₂ on PEMFC performance. Polluted air resulted a significant decrease in performance of PEMFC.