Nanotechnology in Fuel Cells focuses on the use of nanotechnology in macroscopic and nanosized fuel cells to enhance their performance and lifespan. The book covers the fundamental design concepts and promising applications of nanotechnology-enhanced fuel cells and their advantages over traditional fuel cells in portable devices, including longer shelf life and lower cost. In the case of proton-exchange membrane fuel cells (PEMFCs), nano-membranes could provide 100 times higher conductivity of hydrogen ions in low humidity conditions than traditional membranes. For hydrogen fuel cell, nanocatalysts (Pt hybrid nanoparticles) could provide 12 times higher catalytic activity. This is an important reference source for materials scientists and engineers who are looking to understand how nanotechnology is being used to create more efficient macro- and nanosized fuel cells.