Coating materials, electrically active polymers

Bipolar plates uniformly distribute air and fuel supplied to FCs. They remove heat from the active area and carry current from cell to cell. Since they should not be too heavy, they are usually made from aluminum or other light metals. However, they are heavily corroded because of harsh conditions to FCs operation. Problems related to materials used for constraction of PEMFCs were reviewed by Hermaim et al. [112]. One of the solutions proposed in order to solve problems related to bipolar plates was coating them with various polymer-carbon-based composites. However, electric conductivity of such coatings may not be sufficient. Another approach proposed... 

The coating operations begin by mixing the active materials, polymer binder and conductive diluent. The objective of the dry blend is to coat the nonconductive particles of the active material with a thin film of the conductive carbon. This coating provides electrical contact to the current collector for full utilization of all the particles in the mix. The polymer is... 

Conductive Polymers Anodes currently available consist of a conductive-polymer graphite material coated on to a multistrand copper conductor. The polymer provides an active surface but shields the conductor from chemical attack. A non-conductive outer braid may be used to give abrasion resistance and avoid direct contact with the cathode. The finished anode has the appearance of an electric cable and is claimed to have applications for buried/immersed structures and for internal protection of tanks, etc. Anode current densities are typically given as 14-30mAm ... 

In three-dimensional mixed-valence systems, electron transfer can manifest itself as electrical conduction, thermally activated. Most work continues to focus on the better known semiconducting materials such as silicon-boron or silicon nitride " (at low temperature), or organic crystals of the anthracene type (at high temperature),or redox polymer-coated electrodes. In the last-mentioned case, the importance of ion migration as well as electron transfer has recently been emphasized. In the mixed-valent Tl(I)3Tl(III)Cl6, conductivity and isotopic exchange studies have been taken to indicate that cation transfer is the principal charge-carrying mechanism, and not electron transfer as such. " Mossbauer... 

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