**Author details**

According to research conducted by Nam and colleagues, electroplating Cr-C coatings on SS304 offers an excellent conductivity and corrosion resistance [38]. The deposition was done under different current densities, and it was discovered that carbon content of the composite coating decreased with increasing current density. The surface roughness of Cr-C plated at current density of was observed to be smooth and crack-free. In addition, the lowest contact resistance was recorded at this value. Beyond this current density was formation of cracks and

A novel epoxy resin (EP)-based system containing polyaniline (PANI) was developed in the research work carried out by Baldissera and Ferreira [39] The PANI serves as an anticorrosive agent to monitor corrosion behavior of mild steel samples. It was found out that the addition of three different forms of PANI-undoped, sulfonated, and fibers to the epoxy resin increased its corrosion protection capacity. Based on the good outcomes, paints prepared with EP and PANI is able to be used as protective coating to metals even when exposed to aggressive marine

In the study conducted by Hung et al. (2009) [40], coated aluminum and graphite composite bipolar plates were installed in separate single PEM fuel cells and tested under normal operating conditions and cyclic loading. After 1000 hours of operation, samples of both the bipolar plates and the membrane electrode assembly (MEA) were collected and characterized. The purpose was to examine the stability and integrity of the plate's coating and evaluate possible changes of the ionic conductivity of the membrane. The SEM/EDX analysis showed very small variation in the surface composition of the coated aluminum bipolar plate after 1000 hours of operation. Chromium was observed in one of the three cathode samples of the MEA. However, it was confirmed that the released Cr did not react with Pt. The microcracks that were observed in the corrosion resistance coating did not seem to completely penetrate through the substrate layer. Aluminum was also detected in the GDLs that were used in both coated aluminum and graphite composite fuel cell which is believed to come from aluminum

oxide carried by the reactant gases from the uncoated back plate and gas manifold.

Conducting polymers as a new type of material have high redox potential complimented with properties of both metals and polymers. Polypyrrole coatings have gained outstanding recognition over the years as one of the most important conductive polymers successfully used in fuel cells, chemical sensors, batteries, anti-corrosion coatings, and drug delivery systems. Graphite-polypyrrole has been successfully coated on SS316L substrate as the bipolar plate for polymer electrolyte membrane electrode [41]. Synergy of graphite and polypyrrole as com‐ posite imparts good surface barrier and conductive properties. The polypyrrole enhances good corrosion resistance and electrical conductivity. The graphite further improves the electrical

It has been shown that metallic bipolar plates are prone to corrosion attack in the fuel cell environment. In addition, the use of precious noble metals is not economical in meeting the

pinholes in the coating network.

248 Electrodeposition of Composite Materials

conductivity of the bipolar plate.

**4. Summary**

environment.

Peter Odetola1 , Patricia Popoola1\*, Olawale Popoola2 and David Delport1

\*Address all correspondence to: popoolaapi@tut.ac.za

1 Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria, South Africa

2 Centre for Energy and Electrical Power, Department of Electrical Engineering, Tshwane University of Technology, Pretoria, South Africa
