Enabling “Sodium–Metal-Free” Manufacturing of Solid-State Batteries

The Na–metal-free manufacturing approach can improve both the manufacturing and performance of Na metal solid-state batteries. While significant research has been dedicated to Li–metal-free manufacturing, the exploration of Na-based counterparts remains relatively nascent. Similar to Li–metal-free manufacturing, achieving uniform Na deposition remains a challenge when using a solid-state electrolyte. In this work, we demonstrated the ability to plate a uniform 2.0 mAh cm–2 Na metal anode by the simple placement of an Al foil-based current collector on NASICON solid-state electrolyte. The Na anode uniformity was dramatically improved by functionalizing the Al CC with a ∼96 nm thick layer of Au. It was shown that the in situ plated Na is homogeneous and dense and can be reversibly stripped and plated at a Coulombic efficiency of >90%. Our findings advance the understanding of Na nucleation and growth and offer insights into streamlining manufacturing processes for future all-solid-state Na anodes.