Galvanostatic deposition of lithiophilic nanosized LixSn nucleation sides and inorganic-rich@polymer dual layer for anode-free lithium metal batteries

Abstract

Anode-free lithium-metal batteries (AFLMBs) offer high energy density. However, lithium dendrite growth and interfacial instability remain critical obstacles to their commercialization. Here, lithiophilic nanosized (∼5 nm) LixSn combined with an inorganic-rich@polymer dual-layer structure was constructed on a Cu current collector, prepared via a galvanostatic process using a dual-lithium salt electrolyte in a Cu||Cu configuration. The polymer outer layer, initiated by LixSn, reinforces the solid electrolyte interphase (SEI), providing mechanical robustness and enabling stable cycling in an ether-based electrolyte. Furthermore, the Sn and LixSn particle sizes can be effectively tuned by adjusting the galvanostatic discharge current. The nanosized LixSn significantly lowers the nucleation overpotential and creates abundant lithiophilic nucleation sites, resulting in uniform, dense Li plating/stripping. The modified Cu collector demonstrates superior performance in ether-based electrolytes, achieving over 92 % capacity retention after 100 cycles at a current density of 1.5 mA cm−2 and an area capacity of 1.1 mAh cm−2. This work provides a simple, eco-friendly, and scalable approach for fabricating high-performance anode-free current collectors for AFLMBs.