Ag Nanoparticles Decorated N-Doped Carbon Fiber as 3D Host for Robust Li Metal Anode

Three-dimensional (3D) scaffolds are considered a promising pathway to suppress dendrite issues in the Li metal anode. However, the poor Li affinity of carbonaceous materials causes uneven Li deposition. In this study, a Ag nanoparticle-decorated N-doped 3D carbon fiber is designed as a host to construct a composite Li metal anode (Ag-NC@Li). The molten Li can be rapidly and uniformly infused into the carbon fiber scaffold due to the Li wettability of Ag. The lithiophilic Ag and N elements can act as nucleation sites and induce uniform Li deposition due to their low nucleation barriers. Moreover, the 3D carbon-based skeleton not only effectively reduces the local current density and homogenizes the ion flux but also greatly moderates the volume change of Li metal and inhibits the Li dendrite growth. As a result, the Ag-NC electrode exhibits a long-term lifespan for 1000 cycles with ultrahigh Coulombic efficiency (CE) of 99.7%. The Li||LiFePO4 full cells with Ag-NC@Li anode achieve excellent cycle performance for 800 cycles at 1 C with a high-capacity retention of 99.1%. Further, the Ag-NC@Li anodes matched with high-capacity cathodes (>3 mAh cm–2) also manifest high-rate capability and stable cycling life. This work provides a direction for the design of lithiophilic 3D carbon-based hosts toward dendrite-free Li metal anodes.