Crystallization control and defect reduction for superior corrosion resistance of zinc anodes in aqueous zinc-ion batteries
Abstract
Anode corrosion in aqueous zinc-ion batteries (AZIBs) leads to electrochemically inert surface and uncontrolled deposition, severely impeding the batteries' lifespan. Efforts to stabilize the zinc anode have primarily focused on modifying external environmental factors, which seldom address the defects inherent to these zinc anodes. Here, we elucidate the relationship between the prevalent dislocation defects in the pristine commercial Zn and their propensity for severe corrosion in aqueous electrolytes. A pressurized recrystallization strategy that fundamentally suppresses the formation of defects is proposed through a dislocation-based creep mechanism. This strategy induces the formation of a nearly single (002) crystal plane-oriented texture and millimeter-scale grains, which homogenizes the surface potential and effectively suppresses galvanic corrosion. As a result, the zinc half-cell stably operates for over 2500 hours at 10 mA cm−2 and the Coulombic efficiency reaches 99.97%. Furthermore, the as-fabricated zinc–iodine full cell retains 96% and 75% of its initial capacity after 5000 and 20 000 cycles at 2 A g−1, respectively. A large-sized pouch cell is also assembled, achieving a reversible capacity of approximate 120 mAh for over 1500 cycles. The proposed facile and efficient pressurized recrystallization strategy addresses the key issue of zinc corrosion and advances the practical applications of AZIBs.