Novel Electrolyte Membrane for Fuel Cell Utilizing Nano Composite

Abstract

In the previous study [1], we reported the achievement of nano scale particles of carbon black by multiple diazo coupling of specific anchor groups having electrolytic functionality onto the same material. As a result, the pseudo products called as the “liquid” nano carbon (LNC) having average particle size down to the range between 20-30nm, can be isolated by water flush. It is discovered in the present study that the electrolytic groups is the main cause for the significant reduction of the electrical conductivity of the carbon black raw material and believed due to the enhanced proton transport efficiency associated with the electrolytic chemistry. We reported here, a novel type of proton transport material comprised of LNC embedded in a polymer matrix to form proton conducting nano composite. The LNC proves stable nano scale [1] in aqueous environment and the nano composit demonstrated excellent film forming properties with a wide range of binders, especially, aqueous emulsion polymers and highly cross linking polymers. The nano composite also exhibits the excellent uniformity of membrane with well known coating process such as dip coating, spin coating, spray coating, roll coating, blade coating, rod coating, brush painting , inkjet printing.... It is found that the nano composite shows stabilization of DTA/TG data curve over that of the single LNC itself. The nano composite also exhibits remarkable thermal stability over wide range of temperature up to 350C in the ambient environment compared to the Nafion 117, a well known proton exchange membrane (PEM) material in the PEM fuel cell [2] market. In fact, in a PEMFC configuration, the nano composite PEM shows higher current density and 2X higher power efficiency than that of Nafion 117. The PEMFC using LNC nano composite PEM also exhibits superior shelf life exceeding 3.5 months when an aqueous methanol liquid fuel system is continuously fed.