High-Performance Flow Alkali-Al/Acid Hybrid Fuel Cell for High-Rate H2 Generation

Hydrogen (H₂) has been utilized as a versatile feedstock or promising energy carrier in a variety of fields, yet the implementation of high-rate H₂ production presents a grand challenge for its readily accessible application. Herein, a newly alkali-Al/acid hybrid fuel cell (3AHFC) that shows the capability of rapidly producing H₂ upon delivering a considerably high energy density is reported, which is set up by paring Al anode in alkaline anolyte with acidic catholyte and a relatively cheap nanohybrid of Ru nanoparticle decorating crumpled reduced graphene oxide (Ru/c-rGO) as cathode catalysts. It is demonstrated that the 3AHFC can release a power density of up to 240.6 mW cm⁻² with a Faradic efficiency of approaching 99% for fast H₂ generation (300 mA cm⁻²). Such hybrid electrolyte H₂-generation fuel cell can also be extended for either seawater anolyte or metallic Mg anode, presenting great promise for the practice feasibility of on-site H₂ production for applications in tough or even extreme environments.