An Alternative to Lithium Metal Anodes: Non‐dendritic and Highly Reversible Sodium Metal Anodes for Li–Na Hybrid Batteries

Highly reversible, stable, and non‐dendritic metal anode (Li, Na etc.) is a crucial requirement for next‐generation high‐energy batteries. Herein, we have built a Li–Na hybrid battery (LNHB) based on Na plating/stripping, which features a high and stable coulombic efficiency of 99.2 % after 100 cycles, low voltage hysteresis (42 mV at 2 mA cm −2 ), and fast charge transfer. As a result of the Li + electrostatic shield layer, the Na deposition showed cubic morphology rather than dendritic, even at high current density of 5 mA cm −2 . The solvation/desolvation of Li + and Na + were modelled by density functional theory calculations, demonstrating the fast desolvation kinetics of Na + . Owing to the superior performance of the Na metal anode, the LNHB coupled with LiFePO 4 cathode exhibited low voltage hysteresis and stable cycling performance that demonstrates its feasibility in practical applications.