Hierarchically porous Cu current collector with lithiophilic Cu O interphase towards high-performance lithium metal batteries

Abstract

The HPCu-Cu x O can guide homogeneous Li nucleation and provide space to alleviate the volume expansion of Li metal, resulting in a smooth and dendrite-free lithium surface. Lithium metal is one of the most promising anode materials for next-generation electrochemical energy storage due to low electrochemical potential and high specific capacity. However, large volume change and uncontrollable formation of lithium dendrite during cycling severely hinder the practical application of rechargeable Li metal batteries. Herein, we report a hierarchically porous Cu covered with lithiophilic Cu x O (HPCu-Cu x O) via femtosecond laser strategy in about 2 min as current collector for high-performance Li metal batteries. With precisely tunable pore volume and depth as well as lithiophilic Cu x O interphase, the HPCu-Cu x O not only guides homogeneous Li nucleation, resulting in a smooth and dendrite-free lithium surface, but also provides space to alleviate the volume expansion of Li metal anode, achieving excellent structure stability. Consequently, highly stable Coulombic efficiency and ultra-low overpotential of 15 mV even up to 1000 h were achieved at the current density of 1 mA cm −2 . Moreover, the resultant Li@HPCu-Cu x O//LiFePO 4 full battery delivered outstanding cycle stability and rate capability. These results offer a pathway toward high-energy-density and safe rechargeable Li metal batteries.