Conductive Network Endows Uniform Lithium Deposition and Reduced Dead Lithium

Lithium metal batteries (LMBs) face commercialization challenges because of safety risks and undesirable electrochemical characteristics, primarily attributed to the uncontrolled growth of lithium dendrites during cycling. To reduce the current density and embed lithiophilic nitrogen on the surface of Cu foil, an intertwined nitrogen-doped carbon network is constructed in situ by a sequential immersion of Cu foil in TCNQ (7,7,8,8-tetracyanoquinodimethane) solution, followed by calcination. The Cu foil with secondary nitrogen-doped carbon branches (Cu-SC) features a hyperbranched and intertwined conductive network with a large specific surface area. The abundant nitrogen species within this structure promote uniform lithium deposition and facilitate the formation of a homogeneous and compatible Cu/Li interface, effectively inhibiting both lithium dendrite formation and dead lithium accumulation. Furthermore, the branched architecture accommodates the volume change during lithium deposition while maintaining structural integrity throughout the whole cycle. Electrochemical characterizations reveal that the Li–Cu–SC||Li symmetric cell operates continuously for over 3000 h at 0.5 mA cm–2 with a small voltage hysteresis, while the Li–Cu–SC||LFP cell maintains a superb capacity retention over 180 cycles at a 2 C rate. This study established an effective methodology for fabricating durable and dendrite-free lithium metal anodes, representing a significant advancement toward practical LMB applications.