Dual modification of current collector for high-performance lithium metal batteries by laser etching

Despite the lithium metal anode is regarded as the next generation of anode for its high energy density and low redox potential, the huge volume expansion and high reactivity between lithium and electrolyte still limit its application. Herein, a multilayer Cu current collector is designed to accommodate the volume expansion and suppress the high reactivity. Through laser etching, the structure and the chemical component of Cu foil are deeply changed. Planar Cu is etched to construct regular microstructure with different length in interval, which regulate the current density distribution and alleviate the massive volume expansion during the charging process. And the surface of microstructure reacts with air to form lithiophilic phase CuxO layer in situ resulting in stable surface of lithium metal anodes. The simple dual-modification strategy enables the half-cell to achieves a cycle life of over 240 cycles with the CE above 98%. In contrast, the initial Cu only achieve a cycle life of less than 50 cycles. Meanwhile, full battery based on multilayer current collector delivered outstanding cycle stability. This work shows an innovative sight for the modification of current collector and safe Li metal anode.