The Main Types of Fuel Cell

The classification of fuel cells can be done according to several criteria that take into account certain common features. Thus, depending on the type of fuel (gases, solids, liquids), depending on the electrolyte used (liquid or solid), depending on how the fuel is consumed (directly and indirectly), but the most widely used classification method is the one takes into account the operating temperature:


Currently in (or close to) current usage, there are six types of fuel cells, with various operating temperatures, as follows [38,42]:


Each of these fuel cell types has specific characteristics. They have obvious advantages, but also disadvantages (in fact limited possibilities of use, now or in the near future) [24,41,42,56]. Apart from these six types there are others, more or less different from the first ones, which will probably be used in the near future: the zinc-air fuel cell (ZAFC) which uses a zinc anode similar to a battery; the ceramic proton exchanger fuel cell (PCFC), a relatively new type of fuel cell; the regenerative fuel cell (RFC) which is based on the most attractive way of generating hydrogen and oxygen by electrolysis, having the Sun as an energy source; in the fuel cell hydrogen and oxygen produce electricity, heat and water, which is then recycled and used for electrolysis.

With regard to the applicability of these typologies of energy conversion technologies for the stationary applications, five of them have been identified in the specialized literature which are used to serve stationary consumers, as follows: DMFC is particularly suited to the supply of electricity in small domestic applications, while MCFC, PAFC, PEMFC, SOFC are used to serve the large consumer market in the stationary field [45,56–58].
