9.1 Introduction
97
leads to more power generation, high energy densities, easy miniaturization, and
longer shelf life. All of these characteristics are vital for the preparation of powerful
fuel cell for transportable electric devices [8, 9]. This chapter will discuss various
aspects of nanotechnology that are involved in hydrogen fuel cells.
9.2 Fuel Cell Electrolytic Membranes
Different types of nanomaterials have been employed in the hydrogen generation,
decontamination, and storage in fuel cells [13]. In this passage, the nanostructured
membranes employed in fuel cells will be discussed. Nanostructured membranes
have garnered significant attention, particularly the nanostructured proton electrolyte
membrane (PEM) of fuel cells, which have been extensively researched and studied
[14]. The PEM is regarded as the “heart of the fuel cell.” It is the membrane which
has several important abilities like large proton conduction with electrical isolation,
chemical and thermal stability, sufficient mechanical strength, and improved water
administration features over widespread ranges of humidity and temperature [14].
The most commonly employed PEM in fuel cells is Nafion, which fundamentally
consists of perfluorinated polymer [15]. PEM membranes have the issue of poor
performance at high temperatures and low humidity [16]. Nanomaterials are being
used for the eradication of this problem.
In an investigation, Nafion-silicon oxide-phosphotungstic acid nanocomposite
membrane was fabricated via sol–gel method. The nanocomposite membranes were
fabricated by casting the mixture of Nafion solution, phosphotungstic acid, and tetra
ethoxy orthosilane solution. Infrared (IR) spectroscopic analysis confirms the peaks
of silicon oxide and phosphotungstic acid and other inorganic and organic components of the nanocomposite membranes. When the membrane was employed in the
fuel cell for analysis, it showed current density of 82 mA cm
−2 at 0.6 V where
pristine Nafion membrane depicted the current density of 30 m A cm
−2 at 0.2 V at
40% relative humidity and 90 °C temperature. The internal resistance offered by the
membranes was found to be in direct relation with the inorganic constituents. The
prepared membranes performed better than commercial Nafion membranes in terms
of internal resistance, Tafel constants, and overall performance [17].
In another investigation, modified Nafion nanocomposite membranes were fabricated for the purpose of achieving high proton conductivity and water preservation
at lower humidity (~40%) and elevated temperatures (120 °C) along with enhanced
mechanical and thermal strength of the membranes. The nanocomposite membranes
were prepared by the integration of the metal oxide nanoparticles. Sol–gel method
was used for the fabrication of Zr, Si, and Ti oxide nanoparticles and further these
prepared nanoparticles were integrated in the pores of the Nafion membranes. The
membranes fabricated with nanoparticles were entirely clear and homogeneous in
composition, in contrast to the other membranes which turn cloudy due to casting with
large size particles. All the modified nanocomposite membranes showed higher water
retention capacity in comparison to the pristine Nafion membranes at 90 and 120 °C.
97
leads to more power generation, high energy densities, easy miniaturization, and
longer shelf life. All of these characteristics are vital for the preparation of powerful
fuel cell for transportable electric devices [8, 9]. This chapter will discuss various
aspects of nanotechnology that are involved in hydrogen fuel cells.
9.2 Fuel Cell Electrolytic Membranes
Different types of nanomaterials have been employed in the hydrogen generation,
decontamination, and storage in fuel cells [13]. In this passage, the nanostructured
membranes employed in fuel cells will be discussed. Nanostructured membranes
have garnered significant attention, particularly the nanostructured proton electrolyte
membrane (PEM) of fuel cells, which have been extensively researched and studied
[14]. The PEM is regarded as the “heart of the fuel cell.” It is the membrane which
has several important abilities like large proton conduction with electrical isolation,
chemical and thermal stability, sufficient mechanical strength, and improved water
administration features over widespread ranges of humidity and temperature [14].
The most commonly employed PEM in fuel cells is Nafion, which fundamentally
consists of perfluorinated polymer [15]. PEM membranes have the issue of poor
performance at high temperatures and low humidity [16]. Nanomaterials are being
used for the eradication of this problem.
In an investigation, Nafion-silicon oxide-phosphotungstic acid nanocomposite
membrane was fabricated via sol–gel method. The nanocomposite membranes were
fabricated by casting the mixture of Nafion solution, phosphotungstic acid, and tetra
ethoxy orthosilane solution. Infrared (IR) spectroscopic analysis confirms the peaks
of silicon oxide and phosphotungstic acid and other inorganic and organic components of the nanocomposite membranes. When the membrane was employed in the
fuel cell for analysis, it showed current density of 82 mA cm
−2 at 0.6 V where
pristine Nafion membrane depicted the current density of 30 m A cm
−2 at 0.2 V at
40% relative humidity and 90 °C temperature. The internal resistance offered by the
membranes was found to be in direct relation with the inorganic constituents. The
prepared membranes performed better than commercial Nafion membranes in terms
of internal resistance, Tafel constants, and overall performance [17].
In another investigation, modified Nafion nanocomposite membranes were fabricated for the purpose of achieving high proton conductivity and water preservation
at lower humidity (~40%) and elevated temperatures (120 °C) along with enhanced
mechanical and thermal strength of the membranes. The nanocomposite membranes
were prepared by the integration of the metal oxide nanoparticles. Sol–gel method
was used for the fabrication of Zr, Si, and Ti oxide nanoparticles and further these
prepared nanoparticles were integrated in the pores of the Nafion membranes. The
membranes fabricated with nanoparticles were entirely clear and homogeneous in
composition, in contrast to the other membranes which turn cloudy due to casting with
large size particles. All the modified nanocomposite membranes showed higher water
retention capacity in comparison to the pristine Nafion membranes at 90 and 120 °C.