Spatially Orchestrated Ion‐Electron‐Thermal Transport in an Ultralight Fibrous Copper Current Collector for Lithium Metal Batteries

ABSTRACT

Lithium metal batteries promise exceptional energy density but remain constrained by nonuniform Li deposition, severe volume fluctuations, and localized electrochemical‐thermal instability. Here, an ultralight conductive‐gradient current collector (UCG CC) is developed to spatially orchestrate ionic, electronic, and thermal transport through an asymmetric fibrous architecture. The UCG CC is fabricated by unilaterally depositing Cu onto a porous polyacrylonitrile nanofiber membrane, producing a Cu‐rich conductive region with a gradual decrease in Cu content across the electrode thickness. The cyano‐rich fibrous scaffold homogenizes Li ⁺ flux, whereas the interconnected Cu network redistributes electron transport, lowers local current density, and facilitates lateral heat dissipation. This spatially differentiated transport architecture directs Li nucleation toward the Cu‐rich bottom region and enables progressive pore filling, thereby suppressing separator‐facing Li accumulation and accommodating electrode‐volume variation. With an areal density of only 1.24 mg cm ⁻² , the UCG CC enables stable Li plating/stripping for over 2000 h in symmetric cells. Li/UCG CC||LFP full cells retain 82.66% of their capacity after 300 cycles, while pouch cells exhibit stable operation, homogeneous temperature evolution. This work establishes a mass‐efficient fibrous current‐collector platform for coordinating ion‐electron‐thermal transport in high‐energy lithium metal batteries.