3D Hierarchical Cu Nanowire Scaffolds with Rest-Free Symmetric Pulsed Plating/Stripping for Stable Lithium-Metal Anodes

초록

Stabilizing lithium-metal anodes requires cooptimization of the current-collector surface architecture and the deposition protocol. In this study, morphology-controlled Cu-based scaffolds were integrated with symmetric, rest-free pulse-current strategies. Three Cu nanostructures-nanoneedles (NN), 3D hierarchical nanowires (HN), and pinecone-like nanostructures (PLN)-were fabricated by linear sweep voltammetry; CuO-rich HN afforded the most uniform Li nucleation. Pulse durations of 100 ms, 500 ms, and 1 s were then screened; 500 ms was identified as the optimal condition, offering the best compromise between deposition uniformity and interfacial stability. Finally, three protocols were compared at 500 ms: plating/stripping (P-S), plating/rest (P-R), and plating/rest/stripping/rest (P-R-S-R). The rest-free P-S protocol delivered superior durability by leveraging rapid flux reversal for dynamic surface smoothing and helping to preserve the solid-electrolyte interphases. With HN + P-S(500 ms), symmetric cells cycled >1000 h and Li & Vert;Cu half-cells maintained CE >= 90% for >120 cycles, outperforming the other conditions. These results show that eliminating rest periods and rapidly alternating plating and stripping-combined with a lithiophilic 3D host-provides a simple, effective route to durable lithium-metal anodes.

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