Electrochemical Dealloying-Enabled 3D Hierarchical Porous Cu Current Collector of Lithium Metal Anodes for Dendrite Growth Inhibition
Chen Luan, Chen Lu, Bin Li, Lin Zhu, Wenzhen Li
Abstract
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.