Very High Performance Alkali Anion‐Exchange Membrane Fuel Cells

Abstract

Abstract Anion‐exchange membrane fuel cells (AEMFCs) have emerged as an alter‐native technology to overcome the technical and cost issues of proton‐exchange membrane fuel cells (PEMFCs). In this study, we describe a new electrocatalyst for AEMFCs composed of carbon nanotubes (CNTs), KOH‐doped polybenzimidazole (PBI) and platinum nanoparticles (Pt), in which the CNTs are wrapped by KOH‐doped PBI at a nanometer thickness and Pt is efficiently loaded on the wrapping layer. In the electrocatalyst, it is revealed that the CNTs and the KOH‐doped PBI layer function as electron‐ and hydroxide‐conductive paths, respectively, and the large exposed surface of the Pt allows an effective access of the fuel gas. Quantitative formation of the well‐defined interfacial structure formed by these components leads to an excellent mass transfer in the catalyst interface and realizes a high fuel‐cell performance. Membrane electrode assemblies fabricated with the electrocatalyst show a high power density of 256 mW cm −2 . To the best of our knowledge, this is the highest value for AEMFC systems measured in similar experimental conditions.