Magnesium (Mg) foil and three-dimensional nanoporous Mg (3D-NPMg) as anodes in Mg metal batteries (MMBs). The left side shows how the Mg foil leads to uneven Mg deposition, which results in dendritic growth and poor cycling stability. The right side shows how 3D-NPMg provides a hierarchical structure, which allows for uniform Mg deposition, reduces top-plating, and improves the electrochemical performance.

Abstract

This study introduces monolithic three-dimensional nanoporous magnesium (3D-NPMg) fabricated through a scalable solution-based dealloying process as electrodes. By employing a naphthalene-based reductive environment, this approach forms a hierarchically porous 3D structure with clean metallic surfaces, thereby forming a free-standing 3D bicontinuous nanostructure. The resulting 3D-NPMg addresses critical challenges in magnesium metal battery (MMB) anodes, including high polarization, dendritic growth, and limited cycling stability. Electrochemical performance tests show that 3D-NPMg exhibits lower overpotentials, improved charge-transfer kinetics, and a significantly extended cycling life. The interconnected porous structure facilitates efficient ionic transport and uniform Mg deposition, thus suppressing volume expansion and reducing top-plating during cycling. With its rapid oxidation-minimizing synthesis, this solution-based dealloying process offers broad applications across various metals, which can advance the development of stable, high-performance anodes for next-generation MMBs.