Aqueous Rechargeable Sodium-Ion Batteries: From Liquid to Hydrogel

Sodium-ion batteries stand out as a promising technology for developing a new generation of energy storage devices because of their apparent advantages in terms of costs and resources. Aqueous electrolytes, which are flame-resistant, inexpensive, and environmentally acceptable, are receiving a lot of attention in light of the present environmental and electronic equipment safety concerns. In recent decades, numerous improvements have been made to the performance of aqueous sodium-ion batteries (ASIBs). One particular development has been the transition from liquid to hydrogel electrolytes, whose durability, flexibility, and leakproof properties are eagerly anticipated in the next generation of flexible wearable electronics. The current review examines the most recent developments in the investigation and development of the electrolytes and associated electrode materials of ASIBs. An overview of new discoveries based on cycle stability, electrochemical performance, and morphology is presented along with previously published data. Additionally, the main milestones, applications, and challenges of this field are briefly discussed.