Facile Production of Phosphorene Nanoribbons towards Application in Lithium Metal Battery

Like phosphorene, phosphorene nanoribbon (PNR) promises exotic properties but unzipping phosphorene into edge-defined PNR is non-trivial because of uncontrolled cutting of phosphorene along random directions. Here a facile electrochemical strategy to fabricate zigzag-edged PNRs in high yield (>80%) is reported. The presence of chemically active zigzag edges in PNR allows it to spontaneously react with Li to form a Li⁺ ion conducting Li₃P phase, which can be used as a protective layer on Li metal anode in lithium metal batteries (LMBs). PNR protective layer prevents the parasitic reaction between lithium metal and electrolyte and promotes Li⁺ ion diffusion kinetics, enabling homogenous Li⁺ ion flux and long-time cycling stability up to 1100 h at a current density of 1 mA cm⁻². LiFePO₄|PNR-Li full-cell batteries with an areal capacity of 2 mAh cm⁻², a lean electrolyte (20 µl mAh⁻¹) and a negative/positive (N/P) electrodes ratio of 3.5 can be stably cycled over 100 cycles.