Guided lithium nucleation and growth on lithiophilic tin-decorated copper substrate

Lithium metal is the ultimate anode choice for high energy rechargeable lithium batteries owing to its ultra-high theoretical capacity,however,Li dendrites and low Coulombic efficiency(CE)caused by disordered Li plating restrict its practical application.Herein,we develop an ultrathin Sn-decorated Cu substrate(Sn@Cu)fabricated by an electroless plating method to induce ordered Li nucleation and growth behavior.The lithiophilic Sn interfacial layer is found to play a critical role to lower the Li nucleation over-potential and promote fast Li-migration kinetics,and the underlying mechanism is revealed using the first principle calculations.Accordingly,a dense dendrite-free and Li deposition with large granular morphology is obtained,which significantly improved the CE and cycling performance of Li‖Sn@Cu half cells symmetric cells.Symmetric cells using the Li-Sn@Cu electrode display a much-prolonged life span(>1200 h)with low overpotential(~18 mV)at a high current density of 1 mA cm^(-2).Moreover,full cells paired with commercial LiFePO_(4) cathode(1.8 mAh cm^(-2))deliver enhanced cycling stability(0.5 C,300 cycles)and excellent rate performance.This work provides a simple and effective way to bring about high efficiency and long lifespan substrates for practical applications.