In Situ Synthesis of a Lithiophilic Ag-Nanoparticles-Decorated 3D Porous Carbon Framework toward Dendrite-Free Lithium Metal Anodes

摘要

Three-dimensional (3D) porous N-doped carbon nanoflake structures decorated with in situ formed Ag nanoparticles (Ag-NCNS) have been synthesized for the first time by a feasible salt-assisted polymer blowing-up method. The 3D porous carbon materials can be an effective lithium host for the application of lithium metal batteries (LMBs) in addressing the challenging issues of the growth of lithium dendrites and the uncontrollable formation of a solid electrolyte interphase (SEI). The 3D hosts can effectively restrain the growth of Li dendrites by trapping metallic Li in the matrix as well as decreasing local current. Ag nanoparticles act as heterogeneous nucleation sites because of the low nucleation overpotential, and therefore, spatial control of Li metal is realized. The as-fabricated Ag-NCNS electrode presents a dendrite-free plating morphology and long-term cycling stability with the Coulombic efficiency maintained at more than 98% for 200 cycles at 0.5 mA cm(-2) with a cycling capacity of 1.0 mA h cm(-2). In symmetric cells, the Ag-NCNS/Li electrode exhibits much lower voltage hysteresis and stable cycling performance for more than 2000 h.