PEM fuel cell research
2008-02 Calculating the coverage of carbon monoxide adsorbed onto platinum
2008-05 The role of adsorbed hydroxyl species on platinum
2010-08 What happens inside a fuel cell?
This Minireview explores a range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an ‘experimental functional map’ of fuel cell performance.
2010-12 Low-cost fuel cell range extenders
2012-01 Hydrogen PEMFC system for automotive applications
2014-05 Fuel cell supercapacitor passive hybrid system
We describe a 9.5 kWe PEMFC-33 × 1500 F supercapacitor passive hybrid system using no DC/DC converter showing 5% efficiency gain over a non-hybrid system and mitigating 2 out of the 3 main fuel cell degradation mechanisms.
2016-08 Real-time monitoring of PEM fuel cell stack failure
Uneven pressure drops in a 75-cell 9.5-kWe proton exchange membrane fuel cell stack with a U-shaped flow configuration have been shown to cause localised flooding. Condensed water then leads to localised cell heating, resulting in reduced membrane durability. Upon purging of the anode manifold, the resulting mechanical strain on the membrane can lead to the formation of a pin-hole/membrane crack and a rapid decrease in open circuit voltage due to gas crossover. This failure has the potential to cascade to neighbouring cells due to the bipolar plate coupling and the current density heterogeneities arising from the pin-hole/membrane crack. Reintroduction of hydrogen after failure results in cell voltage loss propagating from the pin-hole/membrane crack location due to reactant crossover from the anode to the cathode, given that the anode pressure is higher than the cathode pressure. Through these observations, it is recommended that purging is avoided when the onset of flooding is observed to prevent irreparable damage to the stack.
2016-11 Improving PEM fuel cell performance with short circuiting
A systematic study on the use of short circuiting for the improvement of proton exchange membrane fuel cell performance. G. Gupta, B. Wu, S. Mylius and G. J. Offer. International Journal of Hydrogen Energy. 2016
Proton exchange membrane fuel cells suffer from reversible performance loss during operation caused by the oxidation of the Pt catalyst which in turn reduces the electrochemically active surface area. Many fuel cell manufacturers recommend using short circuiting during the operation of the fuel cell to improve the performance of the cells over time. However, there is lack of understanding on how it improves the performance as well as on how to optimise the short circuiting strategy for different fuel cell systems. We present a simple procedure to develop an optimised short circuiting strategy by maximising the cumulative average power density gain and minimising the time required to recover the energy loss during short circuiting. We obtained average voltage improvement from 10 to 12% at different current densities for a commercial H-100 system and our short circuiting strategy showed ∼2% voltage improvement in comparison to a commercial strategy. We also demonstrated that the minimum short circuiting time is a function of double layer capacitance by the use of electrochemical impedance spectroscopy.