Longevous Sodium Metal Anodes with High Areal Capacity Enabled by 3D-Printed Sodiophilic Monoliths

Abstract

Sodium metal anode, featured by favorable redox voltage and material availability, offers a feasible avenue toward high-energy-density devices. However, uneven metal deposition and notorious dendrite proliferation synchronously hamper its broad application prospects. Here, a three-dimensional (3D) porous hierarchical silver/reduced graphene oxide (Ag/rGO) microlattice aerogel is devised as a sodiophilic monolith, which is realized by a direct ink writing 3D printing technology. The thus-printed Na@Ag/rGO electrode retains a durable cycling lifespan over 3100 h at 3.0 mA cm^-2/1.0 mAh cm^-2, concurrently harvesting a high average Coulombic efficiency of 99.80%. Impressively, it can be cycled for 340 h at a stringent condition of 6.0 mA cm^-2 with a large areal capacity of 60.0 mAh cm^-2 (∼1036.31 mAh g^-1). Meanwhile, the well-regulated Na ion flux and uniform deposition kinetics are systematically probed by comprehensive electroanalytical analysis and theoretical simulations. As a result, assembled Na metal full battery delivers a long cycling sustainability over 500 cycles at 100 mA g^-1 with a low per-cycle decay of 0.85%. The proposed strategy might inspire the construction of high-capacity Na metal anodes with appealing stability.