Hydrogels

Abstract

Metal-ion batteries act as prominent performing electrochemical energy storage devices. To attain a non-flammable, highly stable, and flexible battery, the battery component separators, electrodes, and electrolytes should possess soft flexibility, mechanical durability, thermal stability, and effective electrochemical performance. Lithium-ion batteries dominate the battery industry owing to their high energy density. In this regard, the use of hydrogels is inevitable due to their versatility and stability. Hydrogels are extensively applied in various fields and hold unique properties of stretchability, self-healing, and anti-freezing. The relevance of conventional liquid electrolytes in the electrochemical device can be replaced using hydrogels, which is a convenient candidate for balancing the flowable ionic conductivity with superior mechanical stability. In particular, employing hydrogel as an electrolyte notably controls dendrite growth issues and thus protects lithium-ion batteries from short-circuiting and explosion. In addition, hydrogels as electrolytes can enhance the smooth transport of ions between electrodes to the electrolyte, and thus chemical stability with superior electrochemical performance can be achieved. Hydrogel usage in metal-ion batteries increases the charge/discharge capacity, life cycle, and energy density of flexible batteries. This chapter reviews and depicts the benefits of hydrogels for metal-ion batteries. © 2024 selection and editorial matter, Ram K. Gupta and Anuj Kumar; individual chapters, the contributors.