Abstract
Constructing 3D Cu-based current collectors (CCs) is a promising strategy to stabilize Li metal anodes. However, the intrinsic lithiophobic nature of Cu hinders uniform Li diffusion and induces inhomogeneous Li deposition, whereas the insufficient understanding of stress evolution during Li deposition limits insights into its role in dendrite formation. Herein, a dual-gradient patterned Cu-Ag CC (PCA-CC) is designed with spatially ordered microstructures. The patterned architecture increases the electrode-electrolyte contact area and redistributes local current density through regularly aligned surface microgrooves. A gradient in lithiophilicity and conductivity directs Li nucleation, promoting uniform deposition and improved cycling stability. In addition, the ordered microgrooves provide a pathway for stress relaxation during Li plating, which helps suppress dendrite formation. As a result, the PCA-CC enables stable and durable electrochemical performance. Li/PCA-CC symmetric cells achieve long-term cycling for over 900 h at 1 mA cm~(-2) and 1 mAh cm~(-2). Furthermore, Li/PCA-CC | LFP full cells demonstrate excellent capacity retention and rate capability, maintaining stability across a wide range of rates. This study presents a scalable dual-gradient CC that integrates structural design, surface chemistry, and stress regulation to advance safer and high-performance Li metal batteries.
NETL
NSTL
Wiley