A review of thermoplastic-based low-cost composite bipolar plates for proton exchange membrane fuel cells

PEM fuel cells (PEMFCs) are preferred as a highly favorable, eco-friendly alternate energy source. It directly converts the chemical energy into electrical power, with water as a by-product, without harming the environment. The major issues with PEMFCs are low electrical conductivity, high weight, and high cost. The bipolar plate (BP) is a crucial and indispensable component of PEMFCs. It plays an essential role in performing important functions, including conveying water and reactant gases, facilitating current flow from the membrane electrode assembly to the extremities, and providing mechanical strength. These plates constitute approximately 80% of its weight and 40% of its overall cost. The characteristics of these plates are subjected to modification based on the chosen material and fabrication process. Effective BP materials should possess enough mechanical strength and excellent electrical and thermal conductivity while also being resistant to chemicals and corrosion. BP is generally fabricated from metals, graphite, and polymeric materials. Metallic BP exhibits superior physical, mechanical, and electrical properties but is highly corrosive. On the other hand, graphitic BP is very heavy and possesses low mechanical strength. The PEMFC technology has made significant strides in the stationary field, accounting for over 60% of the global fuel cell market. It offers high efficiency of up to 65%. Companies are developing PEMFCs for various applications, including backup power, forklifts, and buses. Overall, PEMFCs are well positioned for significant growth and development in the coming years, driven by advancements in materials, efficiency, and cost reduction. This article aims to review the utilization of thermoplastic materials as polymer matrix in BP fabrication as alternate materials of graphite and metals. It also covers the various metallic and non-metallic fillers used in polymeric BP, fabrication methods, and comparisons of various properties, including cost.