Breakthrough improvements in conductive polymer boost fuel cell performance and exceed US Department of Energy conductivity targets for automotive applications
Southampton, UK, April 30, 2007: Bac2, the fuel-cell materials company, has announced substantial conductivity improvements for its patented ElectroPhen conductive polymer. Independent test have shown that the latest version of the thermoset material, which uses a new curing agent, demonstrates a dramatic improvement in in-plane electrical conductivity to nearly 500 Siemens per centimeter. Crucially, the material now comfortably exceeds the US Department of Energy conductivity target of 200 Siemens per centimeter for such materials used to make bipolar plates for fuel cell applications. The target primarily relates to fuel cells for use in automotive applications.
Bipolar plates and end plates for connecting to the outside world make up to 70% of the weight and 30% of the cost of a typical Polymer Electrolyte Membrane (PEM) fuel cell stack. Making them from ElectroPhen will deliver substantial cost savings without compromising performance. ElecroPhenís raw state conductivity is in the order of 109 (a billion times) more conductive than commonly used resin binders, which means that no post-processing, such as extreme temperature or surface machining, are required. This makes ElectroPhen plates easy and economical to produce in the high volumes anticipated for full-scale deployment of fuel cells. Furthermore, the ratio of ElecroPhen to graphite resin makes for a tougher plate ñ essential for automotive usage - and further modification with plasticisers, reinforcers, and conductive fillers enable the composition to be fine-tuned for specific applications and customer requirements.
Other important physical characteristics of ElecroPhen are its thermal stability, resilience to temperature and inertness towards fuel cell catalysts and membranes. This means that fuel cell stack manufacturers can safely explore the use of more economical MEA (membrane-electrode assembly) materials that may yield greater efficiency with higher temperatures at the reaction surface. The basic raw materials for ElectroPhen are widely available from major chemical suppliers and curing is achieved at room temperature.