Ultrafast Electrical Pulse Synthesis of Highly Active Electrocatalysts for Beyond‐Industrial‐Level Hydrogen Gas Batteries

Abstract

AbstractThe high reliability and proven ultra‐longevity make aqueous hydrogen gas (H2) batteries ideal for large‐scale energy storage. However, the low alkaline hydrogen evolution and oxidation reaction (HER/HOR) activities of expensive platinum catalysts severely hamper their widespread applications in H2 batteries. Here, cost‐effective, highly active electrocatalysts, with a model of ruthenium‐nickel alloy nanoparticles in ≈3 nm anchored on carbon black (RuNi/C) as an example, are developed by an ultrafast electrical pulse approach for nickel‐hydrogen gas (NiH2) batteries. Having a competitive low cost of about one fifth of Pt/C benckmark, this ultrafine RuNi/C catalyst displays an ultrahigh HOR mass activity of 2.34 A mg−1 at 50 mV (vs RHE) and an ultralow HER overpotential of 19.5 mV at a current density of 10 mA cm−2. As a result, the advanced NiH2 battery can efficiently operate under all‐climate conditions (from −25 to +50 °C) with excellent durability. Notably, the NiH2 cell stack achieves an energy density up to 183 Wh kg−1 and an estimated cost of ≈49 $ kWh−1 under an ultrahigh cathode Ni(OH)2 loading of 280 mg cm−2 and a low anode Ru loading of ≈62.5 µg cm−2. The advanced beyond‐industrial‐level hydrogen gas batteries provide great opportunities for practical grid‐scale energy storage applications.