**4. The new trend in enhancement fuel cell performance**

All types of fuel cells are a good source of green energy, but none is yet suitable enough to replace traditional sources. That leads the designers to spend their efforts on improving efficiency, size, weight, and cost. Some new trends to enhance fuel cell performance are explained as the following:

A single fuel cell generates a little electrical current, so a group of cells is connected in a geometrical form called a stack. The bipolar plates in any fuel cell stack cause most of the weight and participate in the cost. Hence, the dimensions and manufacturing cost of the stick can be significantly reduced if the bipolar plate is removed. Some designers used laser ablation to sculpture microchannels on the cell electrodes to increase the gas flow rate. They found that by this simple idea the bipolar plates could be excluded [32].

Oxidation and reduction process occurs on the surface of the catalyst, which necessitates an increase in the reaction space between the catalyst and the reaction gases. But this contradicts the continuous tendencies to lower the cost of fuel cell since Platinum is very expensive. Although platinum is preferred as a catalyst in most fuel cell types because it is a stable and active substance, a less expensive alternative should be found. So it was replaced by palladium. One way to increase the active surface areas of the catalysts is to reduce particles size. For this, nanotechnology had been used in many research works to manufacture porous nanocatalyst to exclude bulk catalyst and gas diffusion layer [32].

## **5. Conclusions**

According to the explanations given in the previous syllabuses of the chapter, the following conclusions can be reached.

1.Energy extraction by the burning of fossil fuels goes through three stages and in each stage is spent energy to complete the process. Therefore, the efficiency

**233**

*Fuel Cells as a Source of Green Energy*

have not petroleum.

tally friendly.

**Acknowledgements**

sponsorship of academics.

**Author details**

Rabea Q. Nafil1

Baghdad, Iraq

Baghdad, Iraq

\* and Munaf S. Majeed<sup>2</sup>

\*Address all correspondence to: 100068@uotechnology.edu.iq

provided the original work is properly cited.

devices.

*DOI: http://dx.doi.org/10.5772/intechopen.89736*

of internal combustion generators is low. Whereas in fuel cells, production is direct and not subject to Carnot limitations, which increases fuel cell efficiency.

2.Fuel cells use hydrogen gas, which is available in air and can be produced in secondary ways such as the electrolysis of water. Therefore, fuel cells are economical and there are no difficulties in manufacturing them in countries which

3.It does not cause harmful gas emissions and thus it is considered environmen-

4.Using laser and nanotechnology, fuel cells can be manufactured in very small sizes that can be included in micro devices such as mobile phones and medical

The authors are pleased to thank their academic institutions, which are the University of Technology/Department of Applied Sciences and the AL-Nahrain Nanorenewable Energy Research Center/AL-Nahrain University for their continued

1 Applied Physics Branch, Applied Sciences Department, University of Technology,

2 AL-Nahrain Nanorenewable Energy Research Center, AL-Nahrain University,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Thermodynamics and Energy Engineering*

contact with the reactant gases and the electrolyte.

cell performance are explained as the following:

to exclude bulk catalyst and gas diffusion layer [32].

bipolar plates could be excluded [32].

following conclusions can be reached.

**4. The new trend in enhancement fuel cell performance**

The catalysts are special chemical materials used to increase the rate of reactions without being consumed. The main condition of the material to be used as a catalyst is to stay unchanged after reactions. Therefore, they could be recovered from the reaction mixture chemically. The existing of catalysts reduces the reaction energy barrier and thus speeds up the reaction at low temperatures [30]. Most types of fuel cells used platinum (Pt) and its group as a catalyst at the two electrodes. At the anode, the Pt catalyst helps in splitting the hydrogen molecules into free electrons and positive cations. While at the cathode, it enables oxygen reduction [31]. A perfect catalyst for a fuel cell is the one with high electric conductivity, stable during

All types of fuel cells are a good source of green energy, but none is yet suitable enough to replace traditional sources. That leads the designers to spend their efforts on improving efficiency, size, weight, and cost. Some new trends to enhance fuel

A single fuel cell generates a little electrical current, so a group of cells is connected in a geometrical form called a stack. The bipolar plates in any fuel cell stack cause most of the weight and participate in the cost. Hence, the dimensions and manufacturing cost of the stick can be significantly reduced if the bipolar plate is removed. Some designers used laser ablation to sculpture microchannels on the cell electrodes to increase the gas flow rate. They found that by this simple idea the

Oxidation and reduction process occurs on the surface of the catalyst, which necessitates an increase in the reaction space between the catalyst and the reaction gases. But this contradicts the continuous tendencies to lower the cost of fuel cell since Platinum is very expensive. Although platinum is preferred as a catalyst in most fuel cell types because it is a stable and active substance, a less expensive alternative should be found. So it was replaced by palladium. One way to increase the active surface areas of the catalysts is to reduce particles size. For this, nanotechnology had been used in many research works to manufacture porous nanocatalyst

According to the explanations given in the previous syllabuses of the chapter, the

1.Energy extraction by the burning of fossil fuels goes through three stages and in each stage is spent energy to complete the process. Therefore, the efficiency

*3.5.3 The catalysts*

*Nafion chemical chain [28].*

**Figure 5.**

**232**

**5. Conclusions**

of internal combustion generators is low. Whereas in fuel cells, production is direct and not subject to Carnot limitations, which increases fuel cell efficiency.

