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.
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