Interlayer Sodium Plating/Stripping in Van der Waals‐Layered Quantum Dot Superstructure

Abstract Assembling quantum dots (QDs) into van der Waals (vdW)‐layered superstructure holds great promise for the development of high‐energy‐density metal anode. However, designing such a superstructure remains to be challenging. Here, a chemical‐vapor Oriented Attachment (OA) growth strategy is proposed to achieve the synthesis of vdW‐layered carbon/QDs hybrid superlattice nanosheets (Fe₇S₈@CNS) with a large vdW gap of 3 nm. The Fe₇S₈@CNS superstructure is assembled by carbon‐coated Fe₇S₈ (Fe₇S₈@C) QDs as building blocks. Interestingly, the Fe₇S₈@CNS exhibits two kinds of edge dislocations similar to traditional atom‐layered materials, suggesting that Fe₇S₈@C QDs exhibit quasi‐atomic growth behavior during the OA process. More interestingly, when used as host materials for sodium metal anodes, the Fe₇S₈@CNS shows the interlayer sodium plating/stripping behavior, which well suppresses Na dendrite growth. As a result, the cell with Fe₇S₈@CNS anode can keep stable cycling for 1000 h with a high Coulombic efficiency (CE) of ≈99.5% at 3.0 mA cm⁻² and 3.0 mAh cm⁻². Noticeably, the Na@Fe₇S₈@CNS||Na₃V₂(PO₄)₃ full cells can attain a capacity of 88.8 mAh g⁻¹ with a retention of 97% after 1000 cycles at 1.0 A g⁻¹ (≈8 C), showing excellent cycle stability for practical applications. This work enriches the vdW‐layered QDs superstructure family and their application toward energy storage.