Introducing Innovative Electrically and Thermally Conductive Coatings.
American Energy Technologies Company is heavily involved in creation of specialty paints and coatings with engineered electrical and thermal conductivity properties. Majority of our coatings are based on graphite pigments.
For instance, we have developed and brought to the market conductive graphite paint, which noticeably improves discharge capacity of Lead Acid and Lithium battery systems by way of minimizing resistance drop between active material and current collector.
Carbon paint is applied to metal substrates so as to stop corrosion of current collectors, reduce ohmic drop, and improve adhesion of active material to the current collector. AETC’s very own solvent based coating, H100, shows outstanding electrochemical and corrosion protection performance in the above applications.
As shown for the example of coated expanded metal substrate, our coating would typically have a purposively engineered rough petal-like structure (see picture above), so as to ensure a firm mechanical grip with the interface it is in contact with. However, we have had projects, where the coating had to be smooth, as shown in the next figure.
Thermally Conductive Paints and Coatings.
In 2010-11 AETC’s engineered thermally conductive coatings were applied to various elements of the carbon fiber reinforced polymer matrix composites with intended application in the airframe technologies.
In these applications, a unique form of graphitic carbon, known as “expanded graphite” was incorporated within the composite.
The benefit of using expanded graphite is that it has a pronounced thermal conductivity over regular graphite. “Expanded” is a form of processed natural flake graphite, which features unique properties of very high thermal conductivity (~190 W/mK in the direction parallel to graphene layers and ~7 W/mK in the direction normal to graphene layers), very low resiliency, e.g. spring back at applied pressure (less than 8% at 10,000 psi), and very high electrical conductivity (an order of magnitude higher than that for conventional graphites).
Figure to the left depicts precursor graphite fibers and AETC’s expanded graphite-coated fibers – a novel backbone material for use in the carbon fiber reinforced polymer matrix composites. Using the latter material, one should be able to manufacture rather complex shapes, such as cylinders, due to the fact that flexibility of graphite fiber felt is not compromised after deposition of our thermally conductive coating.
Besides airframe applications, American Energy Technologies Company is working with customers from the specialty alkaline battery industry to develop a thermally conductive battery cell case and battery containment trays.
A thermal bottleneck that has been identified through finite element modeling – it is the heat removal from the polymer cell cases. With the advances in application of AETC’s thermally conductive forms of graphite in polymers and composites, an improved material of cell cases is being developed.
Newly developed composites are cast into target shapes and undergo engineering testing. These include: resistance to electrolyte degradation, stability in elevated temperatures, mechanical properties, electrical resistance, and engineering properties such as related to the expected integrity of the material when cast into the form of a cell case. The composition of the composite is being optimized per customer’s specifications, so as to achieve the right balance of electrical vs thermal conductivity characteristics in the finished product.
We encourage interested organizations to contact a representative of American Energy Technologies Company with specifics of your thermally and/or electrically conductive application.