Zinc iso-plating/stripping: toward a practical Zn powder anode with ultra-long life over 5600 h

Abstract

Zn powder with large-scale production and good tunability is promising for aqueous Zn-ion batteries, but its extremely short lifespan seriously hinders the practical application. Herein, we disclose that Zn powder anode failure is majorly caused by top-down plating and bottom-up stripping behaviors. Therefore, an iso-plating/stripping strategy has to be developed accordingly to achieve an ultra-long lifetime Zn powder anode for practical applications. Zincophilic Bi-metal nanosheets are anchored on the Zn powder surface, which could serve as preferred Zn nucleation sites and charge-aggregated protrusions, leading to homogeneous plating/stripping and gradient-free Zn²⁺ distribution throughout the powder electrode. Furthermore, Bi has additional advantages including the ability to guide Zn(002)-orientated growth and suppress side reactions for achieving further structural stability, permitting unprecedented stable cycling of over 5600 h at 1 mA cm⁻² and 585 h even at 15 mA cm⁻². The corresponding Bi@Zn powder//MnO₂ full batteries feature an extraordinary capacity retention of 82.12% after 1150 cycles at 2 A g⁻¹ and a low negative/positive electrode capacity ratio of 6.65. When applied in pouch-type batteries, Bi@Zn powder delivers an impressive energy density of 138.6 W h kg⁻¹ at a superfast power density of 700 W kg⁻¹. This study clarifies the failure mechanism of the Zn powder anode and develops a concise yet effective strategy that paves the way for fabricating practical Zn anodes with a long life and dendrite-free structure.