T‐Nb2O5 Surface Coating Enables a Stable Zinc Anode

The surface reactions of zinc anode, including dendrite formation, corrosion, and passivation, hinder the aqueous zinc‐ion batteries. Surface engineering is one effective strategy for zinc protection. Herein, a high dielectric constant and stable and easily prepared T‐Nb 2 O 5 first demonstrate as the surface coating for zinc anode. The hydrophilic T‐Nb 2 O 5 coating can restrict the migration path of zinc ions and induce the bottom‐up orderly deposition of zinc ions instead of disordered deposition. The T‐Nb 2 O 5 coating zinc anode (T‐Nb 2 O 5 /Zn) shows improved electrochemical performance. The voltage of T‐Nb 2 O 5 /Zn symmetric cell is stable in the long cycle of 1600 h and about 50 mV in the first 20 h and 25 mV in the last 20 h. After 150 cycles, the discharge capacity of T‐Nb 2 O 5 /Zn || MnO 2 full battery is 209 mAh g −1 , showing a capacity retention rate of 94%. The design of T‐Nb 2 O 5 coating provides an attractive strategy for stable and reversible aqueous zinc metal batteries.