Facile Lithiophilic 3D Copper Current Collector for Stable Li Metal Anode

Abstract

Lithiophilic hosts are confirmed to effectively enhance the electrochemical stability of lithium (Li) anodes, thereby guaranteeing the safe, practical application of Li metal as the anode in rechargeable Li-ion batteries. This study reveals a lithiophilic three-dimensional copper current collector (Ag@CF). Silver (Ag) nanoparticles were anchored on the surface of a skeleton of copper foam (CF) via a facile displacement reaction under ultrasonic conditions. The introduced Ag nanoparticle layer reduces the nucleation barrier of Li, leading to a homogeneous Li nucleation and plating. Simultaneously, porous Ag@CF provides the structural support and storage volume of the Li anode, eliminating its volume change in the process of plating/stripping. Benefiting from the above, the Ag@CF electrode shows a superior electrochemical performance in half-type cells (near 100% coulomb efficiency for 350 cycles at 1 mA cm−2). Composite electrodes (Li-Ag@CF) preloaded in the Ag@CF network deliver an ultra-long lifespan of over 1600 h with a low over-potential at 1 mA cm−2 in Li-Ag@CF symmetric cells. Furthermore, LiFePO4∣Li-Ag@CF full cells display enhanced capacity retention (over 80% for 800 cycles at 1 or 3 C). More importantly, this method is facile, large-scalable, and low-cost, which offers an alternation strategy for the practical application of stable Li anodes. Graphical Abstract