6 - Biopolymer Composites in Fuel Cells

Abstract

The wide use of fossil fuels, which resulted in severe pollutant emissions, present a menace to the wellness of mankind. In addition, a steady diminution of world’s limited fossil fuel reserves call for efficient, benign, and sustainable technologies for energy transition and power generation. Fuel cells have been identified as one of the most efficient and promising alternative technologies to traditional power sources due to its lower carbon footprint and greater conversion efficiency. A fuel cell is an energy conversion device that generates DC electrical power by converting the chemical energy of a fuel into electrical energy and heat through catalyzed electrochemical reactions. Fuel cells typically utilize hydrogen as the fuel, and oxygen (or oxygen from the air) as the oxidant. Generally fuel cells are classified based on electrolyte material used, among them polymer electrolyte membranes (PEMs) offer advantages such as high efficiency and high energy density. Nevertheless, most of the present-day polymers that are being presently applied in PEM fuel cell applications are synthetic materials; their biocompatibility and biodegradability are much more limited than those of natural polymers such as cellulose, starch, glycogen, chitin and chitosan, and their derivatives. The utilization of biopolymer for fuel cell technologies is novel and challenging where biological products are usually considered as waste, nonhazardous, and environmentally benign. Especially, the low production cost of the biopolymer is an attractive feature. Hence recently, profusely available biopolymers and their composites have been widely analyzed as materials for membrane electrolytes and electrodes in low to intermediate temperature hydrogen polymer electrolyte fuel cells, direct methanol fuel cells, alkaline fuel cells, and biofuel cells. The chapter provides an overview of applications of novel biopolymers and their composites in fuel cells technology.