Architecture-Controlled Hierarchical Carbon-Based Current Collector for Mitigating Interfacial Instabilities in...

The growing demand for lightweight and high-energy-density storage systems has renewed interest in lithium metal batteries. Despite this interest, their commercialization is still constrained by challenges such as dendritic Li growth and parasitic interfacial reactions. In this study, an architecture-controlled hierarchically porous carbon-based current collector consisting of carbon nanotubes and mildly steam-activated carbon black is proposed, in which controlled defects in the carbon black provide lithiophilic nucleation sites while causing minimal degradation of its electronic conductivity. This lightweight and mechanically robust architecture (0.69 mg cm^{- 2}) ensures efficient electron transport and promotes spatially uniform Li-ion flux, thereby confining lithium nucleation within the porous matrix and effectively suppressing dendrite formation and interfacial instabilities at the Li-metal interface. Electrochemical characterization reveals that the current collector retains 50.4% of its initial capacity at 2C, maintains 77.6% of its original capacity over extended cycling, and achieves an average Coulombic efficiency of 96.2%. Additionally, scanning electron microscopy analysis confirms that Li nucleation predominantly occurs within the internal pore network rather than on the external surface. These findings demonstrate that the proposed architecture-controlled carbon current collector offers a scalable strategy for stabilizing Li-metal anodes in safe, high-energy-density rechargeable batteries for applications in electric mobility and aerospace systems.