Lithiophilic polymer interphase anchored on laser-punched 3D holey Cu matrix enables uniform lithium nucleation leading to super-stable lithium metal anodes

Abstract

Metallic lithium is regarded as the “Holy Grail” among various anode materials for the next-generation rechargeable batteries. Unfortunately, the inhomogeneous Li deposition and uncontrolled dendrite growth during repeated cycling lead to low Coulombic efficiency, poor performance, and serious safety issues. Herein, a novel two-pronged strategy is proposed to effectively guide Li nucleation and suppress the unwanted Li dendrites growth, by a synergized approach of combining the laser-machined 3D holey Cu matrix (3D Cu) and lithiophilic polydopamine (PDA) surface coating layer. The PDA@3D Cu scaffold is shown to exhibit the wanted dendrite-free Li plating/stripping behavior. It delivers a remarkable Coulombic efficiency of 96.4% after 150 cycles (2.0 ​mA ​cm−2 ​at 1.0 mAh cm−2), and achieves an excellent lifespan of over 1000 ​h operation tested in Li/Li symmetric cells, together with good stability for Li//FePO4 full batteries. Our molecular dynamics (MD) simulations, density functional theory (DFT) calculations, and in-situ real-time monitoring using optical microscopy together have established the direct correlation between reversible Li electrodeposition and lithiophilic 3D holey structure scaffold. Significantly, the new findings suggest that a synergistic combination of 3D Cu with lithiophilic PDA coating layer represents an effective pathway to regulate metallic Li anodes towards practical applications.