The interest in developing clean and environmentally-friendly energy devices to be used on vehicles is intensifying because of emissions from conventional internal combustion engines considered as one of the significant contributors to the rapidly changing climate. Fuel cell energy devices, especially the proton exchange membrane (PEM) type, are the solid contender to replace the conventional vehicle propulsion technology in the transport sector. The PEM fuel cell technology needs a lot of efforts to overcome some existing problems such as durability, hydrogen storage, and cost for its successful worldwide commercialisation. This chapter deals with the durability, cost, and performance challenges related to the utilization of PEM fuel cell technology in electrified transportation. Recent advancements concerning the current challenges have been discussed. Moreover, issues of hydrogen storage and infrastructure are outlined.
Top1. Introduction
With the increase of global concerns on climate change, sustainability and development, the interest in using innovative, renewable energy technologies especially PEM fuel cell have been a focus of attention in recent years in the transport sector, due to their higher effeciency, high power to weight ratio, quick start-up time, environmentally friendly nature, potential to replace conventional engine technology and low Green house gas (GHG) emissions (A. Alaswad et al., 2015). A fuel cell is an electrochemical device that converts chemical energy (stored in hydrogen) into electrical energy. Unlike conventional batteries, PEM fuel cell uses external source to supply hydrogen as a reactant to the cell. Similarly, the electrodes in a PEM fuel cell do not participate in the reaction. The applications of PEM fuel cells include vehicles, sub-marines, spacecraft and electricity generators (A. Alaswad et al., 2015, 2016a). PEM fuel cell devices are especially reasonable for use in passenger vehicles, for example, light duty vehicles and heavy duty vehicles.
The transport sector have been cited as one of the major contributors of the GHG emissions into the environment for the past several years (A. Alaswad et al., 2016a). Researchers have been trying to develop fuel cell systems that may capable of using different fuels rather than hydrogen (Ou et al., 2012). Through this developement, the fossil fuel consumption could be significantly reduced in the transport sector and may pave the way for alternative technologies of the same nature for the better and sustainable future (Hao et al., 2010). Consequently,two different approaches have been found in the open literature to manage vehicle GHG emissions issues. The primary approach concerns with the type of fuel that can be applied either by upgrading quality of the conventional fuels or through using alternative fuels (such as bio-fuels), while the secondary approach deals with the vehicle emissions that must be in accordance with the emission standards/measures. These approaches might play a vital role in reducing fuel consumption and GHG emissions in the transport sector (Achour et al., 2011, 2012; Achour & Olabi, 2016; Saboohi & Farzaneh, 2009).
The concept of fuel cell was first introduced by Sir William Grove in 18th century and it was developed in mid of 19th century. Since then, special focus were laid upon development of fuel cell as the researchers/scientists were keen to explore strategies to power spacecrafts through using fuel cell technology (A. Alaswad et al., 2016a). Fuel cells are classified on the basis of electrolyte being utilised. Among all, the most prominent is the PEM fuel cell which uses solid polymer as electrolyte and permeable carbon electrodes (coated with platinum alloy catalyst). The PEM fuel cell uses clean and pure hydrogen supplied from reformers or capacity tanks. As far as the matter of PEM fuel cell working is concerned, the hydrogen is supplied to the anode (where electrons are separated from protons). The protons pass through the permeable membrane and strike the cathode, while the membrane does not allow the electrons to pass through it so that they can make their way through the outer circuit and produce electricity. The water is formed as a by-product on cathode where oxygen combines with electrons and protons. Pure oxygen can be supplied or it can be separated from the air, at the electrode during the process.