Three-dimensional lithiophilic Cu@Sn nanocones for dendrite-free lithium metal anodes

The uneven deposition of lithium (Li) on current collectors causes serious dendrite growth and volume expansion. Commercial foamed copper (Cu) current collectors are unsuitable for Li anodes because of their large volume and mass and lithiophobic nature. Herein, a three-dimensional (3D) copper@tin (Cu@Sn) nanocone current collector with small volume, light weight, and lithiophilic nature was prepared by a simple electrodeposition method. The synergy of the nanoconical structure and lithiophilic Sn promotes the even deposition of Li and effectively inhibits the formation of Li dendrites. The resultant half batteries exhibit high Coulombic efficiency of 97.6% after 100 cycles at 1 mA cm −2 , and the symmetrical Li battery demonstrates a prolonged lifespan of over 600 h at 1 mA cm −2 . The full battery based on organic liquid electrolyte with LiFePO 4 also exhibits a long lifespan of 550 cycles with high capacity retention of 95.1% at 1 C. Moreover, 3D Cu@Sn nanocone-based solid-state batteries exhibit excellent electrochemical performance and show no decay after 500 cycles at 1 C. Our work provides a strategy for fabricating 3D current collectors for high-energy-density Li metal batteries.