Ultra-Stable Zn Metal Batteries with Dendrite-Free Cu-Sn Alloy Induced High-Quality Composite Zn Mesh

Aqueous zinc ion battery with high security, lost cost and excellent performance has been one of the most potential storage energy devices. However, the dendrite formation on Zn anode is a stumbling block on the road of development. Utilizing three-dimension (3D) substrates is a valid method to suppress dendrite through reducing local current. Yet, they are also confronted with the issue of uneven deposition. Herein, a low-nucleation-barrier Cu-Sn alloy layer on a stainless-steel mesh (Cu-Sn@SSM) is constructed firstly by a facile co-electrodeposition strategy to eliminate the dendrites formation. The Cu-Sn alloy can easily compound with Zn and transform into Cu-Zn alloy and Sn metal, thus realizing the homogenization of ion distribution and the densification of Zn deposition. As a result, the Cu-Sn@SSM scaffold delivers remarkable Coulombic efficiency (99.4 % for more than 2000 cycles) with an appreciably low nucleation potential of 1 mV at a high current density of 10 mA cm -2 . Such high-quality Zn mesh (Zn@Cu-Sn@SSM) exhibits improved uniformity of Zn plating and effective inhibition of side reactions. A long lifespan of more than 1050 h at 10 mA cm -2 with a capacity of 3 mAh cm -2 can be achieved in Zn@Cu-Sn@SSM symmetric cell. Notably, when pairing with NVO cathode, the full battery renders a capacity of 162 mAh g -1 after 1000 cycles at 2 A g -1 (vs. evident capacity decay and only 400 cycles for the counterpart with Zn@SSM).