In situ synthesis of lithiophilic Ag sites in 3D MOF-derived nitrogen-doped porous carbon composites towards dendrite-free lithium metal anodes†

Abstract

The uncontrolled dendritic lithium growth and excessive volume expansion pose significant challenges to the practical applications of metallic lithium, which is considered as the most promising high-energy-density anode material for rechargeable batteries. In this work, derived from metal organic framework (MOF), we design a novel Ag@nitrogen-doped porous carbon framework (Ag@NPCF) composite with silver (Ag) nanoparticles uniformly distributed. The 3D MOF microporous structure effectively stabilizes the volume changes during the repetitive plating/stripping of Li. Lithiophilic nitrogen-doped carbon and Ag nanoparticles, acting as uniform nucleation sites reduce local current density and guide uniform nucleation and deposition of Li ions. Therefore, the Ag@NPCF electrodes displayed excellent cyclic stability for over 600 cycles with 98.8% coulombic efficiency and a stable cyclic lifespan of 1600 h in the symmetrical cells. Additionally, full cells coupled with an LiFePO₄ commercialized cathode deliver excellent cyclic and rate performance.