Calendar aging of zinc-ion batteries

Zinc-ion batteries (ZIBs) have garnered significant attention as potential candidates for large-scale energy storage. In recent years, researchers have made notable progress in extending the cycle life of ZIBs. However, another critical factor, calendar aging, also plays a significant role in applying ZIBs practically. The current research achievements and expectations for the practical application of ZIBs highlight the urgent need for an in-depth investigation of their calendar aging. Nevertheless, the stimuli affecting the calendar aging of ZIBs remain unclear. Before conducting a systematic study, it is essential to identify and clarify the stimuli that may influence the calendar aging of ZIBs and understand the interlaced relationships between them. This perspective comprehensively discusses the potential effects of internal stimuli, such as Zn anode passivation, Zn depletion, electrolyte consumption, and cathode dissolution, as well as external stimuli, including the state of charge (SOC), temperature, pressure, and battery packaging, on the calendar aging of ZIBs. Additionally, some promising research methods are proposed to help researchers further understand and improve the calendar aging of ZIBs.