Developing advanced bifunctional water splitting electrodes that can perform both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is critically important for sustainable hydrogen production because of the simplicity...

Metallic aerogels emerge as a group of materials for various applications since they exhibit the merits of both metal and aerogel. However, their performance characteristics are largely depreciated by the poor compressibility, elasticity, and complicated preparation process. Herein, a highly compressible and air-dryable nickel nanowire aerogel (NNWA) is prepared via a facile magnetic-field-assisted gelation strategy. Its unique anisotropic lamellar structure and abundant cold-welded junctions of intertwined nanowires enable superior electric conductivity and compression fatigue resistance. Such a free-standing NNWA featured with ultralow density (20 mg cm −3 ) can be directly used as electrode scaffolds for energy storage and electrocatalysis purposes even at high mass loading (e.g., 10 mg cm −2 ) and large current density (e.g., 1 A cm −2 ) with superior performance. This method represents a general strategy for producing metallic aerogels with excellent comprehensive performance and mass-production capability, providing a versatile platform for advanced applications.

Poor stability of nanostructured electrocatalysts at rigorous industrial conditions significantly inhibits their performances in practical electrolyzers. Although many substrate‐supported nanostructured electrocatalysts present attractive performance at small currents, they cannot sustain industry‐level high current densities for long‐term operation. Herein, by chemically organizing nanoscale electrocatalysts into a macroscopic substrate‐free metallic alloy aerogel, this NiFe‐based nano‐catalyst achieves 1000‐h durability at industrial‐level current densities, with exceptionally high activities of 500 mA at the overpotential of only 281 mV. This NiFe alloy aerogel is constructed by a magnetic‐field assisted growth and assembly of ferromagnetic NiFe nanoparticles, in which nanowires are loosely crosslinked by metallic joints. This alloy aerogel shows a high electric conductivity of 500 S m−1, structural stability for more than 1.5 years in alkaline electrolyte, and almost complete recovery after compression exceeding 50% strain for 1000 cycles. The excellent mechanical stability of this metallic aerogel behaves as the key contributor to the superior electrocatalytic stability under industrially relevant conditions. This work offers a paradigm for electrode design for the practical application of nano‐catalysts in industrial alkaline water electrolysis.