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

Abstract

The 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.

Non-Noble Metal High-Entropy Alloy-Based Catalytic Electrode for Long-Life Hydrogen Gas Batteries

“…14,45 However, this will not affect its application in Ni-H 2 batteries, because it only requires a low enough overpotential to drive the reversible HER/HOR process. 46 The exchange current density (j 0 ) of NNM-HEA@CF can be estimated from the micropolarization region (−5 to 5 mV vs RHE) according to the simplified Butler−Volmer equation…”

“…By contrast, the Pt/C@CF cannot support a current density of 10 mA cm –2 below 0.3 V, suggesting the superior HOR activity of NNM-HEA@CF under alkaline conditions (Table S3). The breakdown voltage of NNM-HEA@CF is higher than 0.25 V, which may be due to the surface passivation of the activate sites at high potentials, thus inhibiting the adsorption of H 2 molecules. , However, this will not affect its application in Ni-H 2 batteries, because it only requires a low enough overpotential to drive the reversible HER/HOR process …”

RuNi single-atom alloy anchored on rGO as an outstanding bifunctional catalyst for efficient electrochemical water splitting

“…30 In addition, Chen et al prepared RuNi alloy nanoparticles anchored on a carbon substrate (RuNi/C) with an ultra-low HER overpotential of 19.5 mV at a current density of 10 mA cm −2 . 31 In spite of these achievements, the fabrication process of RuNi/carbon composites is usually tedious and expensive, and the electrocatalytic performance still need to be improved to meet the demand of large-scale commercial application. Therefore, it is still a daunting challenge to construct novel RuNi/carbon-based catalysts with excellent electrocatalytic properties with a simple and cost-effective strategy.…”

Rechargeable Hydrogen–Chlorine Battery Operates in a Wide Temperature Range

“…With growing concerns over energy and the environment, the pursuit for renewable solar and wind energy is of great prominence. Due to the intermittence of these sustainable energies, however, their integration into the electrical power grid has become urgent and indispensable. − Developing robust energy storage systems is thus vital to mitigate conventional energy depletion and provide an option to address the intermittent issues of renewable energy. − Hydrogen-based fuel cells offer a promising solution given the abundance of hydrogen gas (H 2 ) and its sustainable nature. , Endeavors have been made to develop catalysts with high activity toward the hydrogen oxidation reaction (HOR) to facilitate the performance of the fuel cell, , or the reverse hydrogen evolution reaction (HER) to produce H 2 with a high rate. , The hydrogen–chlorine (H 2 –Cl 2 ) fuel cell is one derivative of the well-known hydrogen–oxygen fuel cell to render high-power-density characteristic due to the fast kinetics of the Cl 2 /Cl – redox couple compared to the sluggish oxygen redox reactions with a four-electron transfer . Besides, the Cl 2 /Cl – redox couple features a high redox potential (1.36 V vs SHE) and a specific capacity of 755 mAh/g .…”