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

Highlights: • An in-situ CuO @ Cu mesh reinforced Li metal anode is prepared. • CuO Nanostick can help to reduce the Li nucleation overpotential to 11 mV. • 3D structure can alleviate the aggressive volume changes of Li anode. • An average CE of 99.5% could be achieved over 250 cycles at 1 mA cm⁻². • 12 mV overpotential and 600 h cycle life are achieved at 5 mAh cm⁻². -- 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.