Sandwiched Li plating between Lithiophilic-Lithiophobic gradient Silver@Fullerene interphase layer for ultrastable lithium metal anodes

Abstract

Constructing a multi-functionally artificial interphase layer is an emerging strategy to possibly address the issues of inhomogeneous Lithium (Li) nucleation and dendrite growth. In this study, a silver@fullerene (Ag@C60) interphase layer with lithiophilic-lithiophobic gradient was designed, which was fabricated by series of deposition of silver and fullerene (Ag@C60) on Cu foam current collector (ACCF). In this way, the typically uncontrolled Li deposition process will become a highly nucleation-guided process, due to the preferentially induced Li nucleation of Ag nanoparticles, which will guide the Li deposition sandwiched in C60 and Ag layers. While the top lithiophobic fullerene layer is beneficial for regulating uniform Li-ion flux and facilitating the formation of LiF-rich SEI layer, finally suppressing the top deposition of Li metal, due to the high nucleation energy barrier on fullerene. Consequently, Li@ACCF exhibits a low overpotential of 14 mV and an ultra-stable cyclic life for more than 2500 h in symmetric cells. Besides, it also displays excellent long-term cycle life and high-rate performance in lithium-metal full cells. This deliberate design of the “push–pull” Li could ensure the uniform Li deposition sandwiched fullerene and silver layers and provide a feasible and efficient approach to advance the practical use of lithium-metal anodes for high-energy–density batteries.