Anisotropic Nanoporous Nickel Obtained through the Chemical Dealloying of Y2Ni7 for the Comprehension of Anode Surface Chemistry of Ni‐MH Batteries

For the first time, the nickel layer formed during the corrosion of intermetallic alloys with a stacked structure has been isolated. This nickel layer has been produced by chemical dealloying of Y2Ni7 through a corrosion process in alkaline medium. This anisotropic and nanoporous phase has been fully characterized regarding its morphology, chemical and structural properties, as well as its electrochemical behavior. The metallic phase is made of interconnected nanocrystalline cubic nickel, showing preferential orientation and nanopores. A cavity microelectrode has been used in addition to classical methods using bulk electrodes for electrochemical investigations of the layer. This full characterization is of primary importance to better understand the behavior of metallic anodes in Ni‐MH batteries upon cycling and to ensure a longer lifetime. Increased life expectancy: An anisotropic nanoporous and nanocrystalline nickel material is produced by chemical dealloying of stacking‐structure Y2Ni7. A cavity microelectrode is used in addition to classical bulk electrodes for electrochemical investigations. This enables an increased understanding of the behavior of metallic anodes in Ni‐MH batteries to ensure a longer lifetime.