In situ formation of a lithiophilic surface on 3D current collectors to regulate lithium nucleation and growth for dendrite-free lithium metal anodes

As the most promising anode material for lithium batteries, lithium metal faces rigorous challenges such as uncontrollable Li dendrite growth and safety risks, which hinder its practical applications. Herein, a uniform indium layer-decorated Ni foam is constructed as a three-dimensional current collector by electroplating to understand the effects of different substrates on the Li deposition morphology and electrochemical performance and to explore the mechanism for Li dendrite growth. The results indicate that an In3Li13 alloy layer is formed by an alloying reaction, which provides abundant nucleation sites for uniform Li deposition. Both simulations and experiments demonstrate that Li ions tend to deposit on the In3Li13 substrate rather than the Li nucleus, while they prefer to plate onto Li particles rather than onto the Ni substrate. Benefiting from the strong interaction, the In3Li13 substrate shows dispersed Li deposition behavior with a grain-like shape, which is different from the severe dendrite formation of bare Ni substrate. As a result, the In3Li13@NF electrode delivers an enhanced Coulombic efficiency of 97.4% for 300 cycles even under a severe cycling condition of 2 mA cm-2, and the Li-In3Li13@NF anode presents increased cycling stability in symmetric cells. Impressively, the Li-In3Li13@NF// LiFePO4 full cell delivers a remarkable capacity retention of 82.8% for 1000 cycles at 2 C. This work not only sheds light on the growth mechanism for Li dendrites but also provides a new strategy to develop high-energy density lithium metal batteries.