High-Performance Solid Acid Fuel Cells Through Humidity Stabilization

Although they hold the promise of clean energy, state-of-the-art fuel cells based on polymer electrolyte membrane fuel cells are inoperable above 100°C, require cumbersome humidification systems, and suffer from fuel permeation. These difficulties all arise from the hydrated nature of the electrolyte. In contrast, "solid acids" exhibit anhydrous proton transport and high-temperature stability. We demonstrate continuous, stable power generation for both H₂/O₂ and direct methanol fuel cells operated at ∼250°C using a humidity-stabilized solid acid CsH ₂PO₄ electrolyte.