Nanoporous Pb Anodes for Sodium-Ion Batteries Synthesized by Free Corrosion Dealloying of Pb-Na Parent Alloys in Pure Water

Abstract

Lead (Pb) is a highly promising anode material for sodium-ion batteries (SIBs) due to its high theoretical volumetric capacity, a suitable working potential above the Na-plating threshold, and low cost. However, its practical application is severely hindered by sluggish sodiation kinetics and massive volume expansion (∼365%) during cycling, which leads to pulverization and rapid capacity fading. Herein, we report a green, scalable, and ultrafast liquid-phase dealloying strategy to fabricate three-dimensional (3D) nanoporous Pb (NP-Pb) with a bicontinuous ligament–pore structure. By leveraging the specific thermodynamic immunity of Pb in neutral aqueous media (based on Pourbaix diagrams) and the distinct chemical activity differences in a Na-rich precursor (Na90Pb10), we achieved the selective removal of the sacrificial Na phase within only 1 min in pure water. The resulting NP-Pb structure effectively accommodates the mechanical strain of volume expansion and provides abundant active sites for rapid Na+ transport. Consequently, the NP-Pb anode exhibits superior electrochemical performance compared to commercial Pb microparticles, delivering a high reversible capacity of ∼480 mAh g–1 at 0.1C with exceptional rate retention of 350 mAh g–1 at 5C (73%), and robust cycling stability. Kinetic analysis reveals that the improved performance stems from a markedly reduced charge-transfer resistance and a high Na+ diffusion coefficient, confirming that the nanoporous architecture effectively shortens solid-state diffusion pathways. This work not only revitalizes Pb-based anodes for SIBs but also offers a sustainable, etchant-free, water-based manufacturing route for advanced porous metal electrodes.