Zincophilic Cu/flexible polymer heterogeneous interfaces enable stable zinc metal anode

Aqueous zinc-ion batteries (AZIBs) are regarded as promising electrochemical energy storage systems for various applications because of their high safety, low cost, and high capacity. However, dendrite formation and side reactions occurring during zinc plating/stripping, greatly reduce the capacity and cycle life of the battery and subsequently limit its practical application. To address these issues, the surface of the zinc anode was modified by functional double layers, which consist of a zincophilic Cu layer and a flexible polymer layer. The zincophilic Cu interfacial layer was prepared by CuSO4 solution pretreatment, which works as a nucleation site to guide uniform Zn deposition, while the polymer layer acting as a protective layer was coated onto the Cu interface layer to prevent side reactions between zinc and electrolytes. Benefiting from the synergistic effect of a zincophilic Cu layer and a polymer protective layer, the symmetric battery exhibits an impressive cycle life of over 2900 hours at the current density of 1 mA·cm-2 with the capacity of 1 mAh·cm-2. Moreover, the full battery paired with vanadium oxide cathode achieves a remarkable capacity retention of 72% even after 500 cycles.