Flexible Lignin Carbon Membranes with Surface Ozonolysis to Host Lean Lithium Metal Anodes for Nickel-Rich Layered Oxide Batteries

The implementation of the high-capacity Li metal anode in practical batteries has not been successful due to the short lifespan and severe safety concerns resulting primarily from low Coulombic efficiency and Li dendritic growth. Lightweight carbon skeletons are considered promising for hosting the lithium metal anode to overcome these limitations. Furthermore, the lithium metal loading must be minimized from the cost and safety standpoint, leading to the need of developing long cycle life “lean Li metal anodes”. Herein, we report a surface ozonolysis approach to homogenize Li nucleation sites and to guide the uniform Li metal deposition on flexible oxygen-enriched lignin-derived carbon membranes (OLCMs). The resulting lean OLCM@Li composite anode allows for stable Coulombic efficiency (>98% over 230 cycles), long cycle life (>1, 000 h), and small voltage hysteresis (<20 mV) in OLCM@Li||Li cells. When assembled in nickel-rich layered oxide batteries with the LiNi0.8Co0.1Mn0.1O2 cathode, the lean OLCM@Li composite anode enables highly reversible capacity, high Li utilization, and improved cell cycle life. Therefore, the low-cost and mild surface ozonolysis processed lignin-based carbon membranes represent a promising class of materials for stabilizing lean Li metal anodes.