Electrochemical Dealloying-Enabled 3D Hierarchical Porous Cu Current Collector of Lithium Metal Anodes for Dendrite Growth Inhibition

Lithium metal anodes are the most attractive for high-energy-density batteries because of their high theoretical capacity of 3860 mA h g–1. However, their practical application is hindered by many challenges such as lithium dendrite growth, volume change of anodes, unstable anode/electrolyte interphase, and so on. Here, we demonstrate a three-dimensional hierarchical porous copper (3DHP Cu) current collector derived using a highly efficient electrochemical dealloying method that can suppress lithium dendrite growth during cycling. The micropores on the surface of the porous copper facilitate the insertion/extraction of lithium ions, which accelerates fast electrochemical reaction kinetics, and the interconnected copper network within the porous copper holds the volume change during lithium plating/stripping. Moreover, the nanopores on the surface further enable a high surface area and even current distribution. Symmetric cells assembled with the 3DHP Cu exhibit stable cycling over 850 h at 1 mA cm–2 with a low voltage hysteresis of 33 mV. In addition, compared with a full cell using a planar Cu foil, a Li@3DHP Cu||LiFePO4 full cell exhibits better cycle stability that results in 110.2 mA h g–1 at 1C after 150 cycles. Our work paves the way for developing safe and longevous lithium metal anodes with a porous Cu current collector derived using a highly efficient electrochemical dealloying strategy.