A 3D lithium metal anode reinforced by scalable in-situ copper oxide nanostick copper mesh

Abstract

Lithium metal anodes (LMAs) have exceptional promises for rechargeable Li-metal batteries. However, their practical applications have long been hindered by the safety concerns related to excessive Li dendrite growth and huge volume expansion during cycling, especially in high-capacity cycles. In this work, we developed a new strategy to suppress the dendrite growth via a 3D reinforced lithium metal composite anode with a nanostick structured copper oxide @copper mesh. Such nanostick structured copper oxide would not only reduce the lithium nucleation overpotential to 11 mV, but also would uniformly accommodate lithium ions to suppress the dendrite effect. Moreover, the 3D structure of copper mesh could effectively alleviate the aggressive volume changes of the lithium metal electrode after hundreds of cycles. Based on CuO@copper mesh, highly reversible lithium stripping/plating are achieved for LMAs at current density of 1 mA cm–2 with a limited volume fluctuation of 13.6% after 1000 h. With ultrahigh capacity densities of 5 mAh cm−2, the CuO@Cu mesh/Li cell exhibits low overpotential of 12 mV and ultralong cycle life over 600 h, which is 2–3 times of the reported average cycling lifespan. The proposed preparation process is simple and easy to scale-up, demonstrating a promising prospect as a commercial Li metal anode with large capacity.