Polymer electrolytes early years developments

Fuel cells [i.e., polymer electrolyte membrane fuel cells (PEMFCs)] in vehicle drivetrains returned to the agenda in the early 1990s with the Mercedes-Benz NECAR van in 1994. A substantial number of concepts have been developed since then, and several manufacturers envisage market introduction within a few years. The following section describes in detail concepts and components of fuel cell (hybrid) electric vehicles. 

Since the realization in the early 1980s that poly(ethylene oxide) could serve as a Hthium-ion conductor in Hthium batteries, there has been continued interest in polymer electrolyte batteries. Conceptually, the electrolyte layer could be made very thin (5 rm) and so provide higher energy density. Fauteux et al. [47] reviewed the state of polymer electrolyte technology in 1995. To summarize here briefly, a polymer electrolyte with acceptable conductivity (>10 Scm ), transport number (>0.9), mechanical properties, and electrochemical stability to high voltage positives has yet to be developed. Ten years later the situation has not changed. 

Electrochemical technology has a history dating back deep into the nineteenth century and carbon electrodes have been major players in this success [1-4]. In the early cells for both the two largest electrolytic industries, chlor-alkali and aluminum extraction, the electrodes were blocks of carbon or graphite. The past 50 years, however, has seen the development of carbons with different structures and often their availability in a range of forms. Thus, it is possible to purchase electrodes based on graphites, carbons, thermally treated carbons (e.g., vitreous or glassy carbon), expanded carbons, carbon/polymer composites, and doped diamond materials. Moreover, some of these materials are available in many forms as follows ... 

---