A Hierarchical Silver‐Nanowire–Graphene Host Enabling Ultrahigh Rates and Superior Long‐Term Cycling of Lithium‐Metal Composite Anodes

Abstract Metallic lithium (Li) is a promising anode for next‐generation high‐energy‐density batteries, but its applications are still hampered due to the limited charging/discharging rate and poor cycling performance. Here, a hierarchical 3D porous architecture is designed with a binary network of continuous silver nanowires assembled on an interconnected 3D graphene skeleton as the host for Li‐metal composite anodes, which offers a significant boost in both charging/discharging rates and long‐term cycling performance for Li‐metal batteries. This unique hierarchical binary network structure in conjunction with optimized material combination provides ultrafast, continuous, and smooth electron transportation channel and non‐nucleation barrier sites to direct and confine Li deposition. It also offers outstanding mechanical strength and toughness to support massive Li deposition and buffer the internal stress fluctuations during long‐term repeated Li stripping/plating thereby minimizing fundamental issues of dendrite formation and volume change even under ultrafast charging/discharging rates. As a result, the composite anode using this hierarchical host can work smoothly at an unprecedented high current density of 40 mA cm ‐2 over 1000 plating/stripping cycles with low overpotential (<120 mV) in symmetric cells. The as‐constructed full cell, paired with LiNi 0.5 Co 0.2 Mn 0.3 O 2 cathode, also exhibits excellent rate capability and high‐rate cycling stability.