Controlled Lithium Deposition on Alq ₃ Coated Substrate

High theoretical charge capacity (3,860 mAh g⁻¹) and low redox potential (−3.04 V vs. standard hydrogen electrode) make lithium metal a promising anode for next-generation high energy density battery. However, the practical implementation of Li-metal anode is still elusive due to poor coulombic efficiency and cycling performance as well as safety concerns caused by lithium dendrite formation and poor compatibility of liquid electrolyte with lithium. In this work, we developed a strategy to control lithium deposition and growth by using surface modified electrodes coated by a conductive chelate compound tris-(8-hydroxyquinoline) aluminum (Alq³) onto copper current collector. As a result, Alq₃ exhibits good conductivity and electrochemical stability verified by cyclic voltammetry test. The Alq₃ can modulate lithium metal growth on Cu surface, in addition, it demonstrates morphology control of deposited lithium by tuning variables such as current density and coating thickness. Optimal cycling stability and stable coulombic efficiency over 300 cycles are observed on the Li||Alq₃/Cu cell at 50 nm coating thickness – an evidence shows controlled lithium deposition by this simple but effective surface modified electrode.