Challenges and protective strategies on zinc anode toward practical aqueous zinc-ion batteries

Over the past decades, there has been a growing interest in rechargeable aqueous Zn-ion batteries (AZIBs) as a viable substitute for lithium-ion batteries. This is primarily due to their low cost, lower redox potential, and high safety. Nevertheless, the progress of Zn metal anodes has been impeded by various challenges, including the growth of dendrites, corrosion, and hydrogen evolution reaction during repeated cycles that result in low Coulombic efficiency and a short lifetime. Therefore, we represent recent advances in Zn metal anode protection for constructing high-performance AZIBs. Besides, we show in-depth analyses and supposed hypotheses on the working mechanism of these issues associated with mildly acidic aqueous electrolytes. Meanwhile, design principles and feasible strategies are proposed to suppress dendrites' formation of Zn batteries, including electrode design, electrolyte modification, and interface regulation, which are suitable for restraining corrosion and hydrogen evolution reaction. Finally, the current challenges and future trends are raised to pave the way for the commercialization of AZIBs. These design principles and potential strategies are applicable in other metal-ion batteries, such as Li and K metal batteries.