Hydrogel Electrolyte Enabled High‐Performance Flexible Aqueous Zinc Ion Energy Storage Systems toward Wearable Electronics

Abstract

To cater to the swift advance of flexible wearable electronics, there is growing demand for flexible energy storage system (ESS). Aqueous zinc ion energy storage systems (AZIESSs), characterizing safety and low cost, are competitive candidates for flexible energy storage. Hydrogels, as quasi‐solid substances, are the appropriate and burgeoning electrolytes that enable high‐performance flexible AZIESSs. However, challenges still remain in designing suitable and comprehensive hydrogel electrolyte, which provides flexible AZIESSs with high reversibility and versatility. Hence, the application of hydrogel electrolyte‐based AZIESSs in wearable electronics is restricted. A thorough review is required for hydrogel electrolyte design to pave the way for high‐performance flexible AZIESSs. This review delves into the engineering of desirable hydrogel electrolytes for flexible AZIESSs from the perspective of electrolyte designers. Detailed descriptions of hydrogel electrolytes in basic characteristics, Zn anode, and cathode stabilization effects as well as their functional properties are provided. Moreover, the application of hydrogel electrolyte‐based flexible AZIESSs in wearable electronics is discussed, expecting to accelerate their strides toward lives. Finally, the corresponding challenges and future development trends are also presented, with the hope of inspiring readers.

Hydrogel-stabilized zinc ion batteries: progress and outlook

“…With the advancements in sensor technology and flexible display technology, there is a growing and urgent demand for energy storage devices (ESDs) compatible with these developments. [1][2][3] In addition to providing a consistent power supply, ESDs for wearable electronics must also possess the necessary flexibility. Traditional ESDs, due to their rigidity, bulkiness, and cumbersome nature, are unable to meet the requirements of wearable electronics.…”

Design Principles and Development Status of Flexible Integrated Thin and Lightweight Zinc-Ion Batteries

“…Therefore, a key focus should be placed on the rational selection of materials and the design of the battery structure to enhance energy density. Additionally, ensuring outstanding cycle performance is essential [12,13] in the development of thin and lightweight zinc-ion batteries. In the realm of research and development for thin and lightweight zinc-ion batteries, there are five fundamental research directions that merit attention.…”

High toughness antifreeze conductive double network zwitterionic gel electrolyte for flexible supercapacitors

“…Great efforts have been made to develop flexible energy storage systems, but maintaining mechanical and electrochemical stability during multiple irregular bending processes is still a major challenge, device integrity is compromised, and it is not possible to design and fabricate flexible shapes of devices that can be scaled, stretched, and so forth 9–12 . In recent years, conductive hydrogel electronic materials designed with hydrogel as a substrate have experienced rapid development, 13–15 showing broad application prospects in the field of flexible electronics, such as electronic skin, flexible sensors, and flexible supercapacitors 16–19 . However, the water content of hydrogel is usually more than 90%, when the ambient temperature is lower than the freezing point, the water molecules tend to arrange in an orderly and regular manner to form a more stable ice crystal state, which leads to the freezing phenomenon of traditional hydrogel, thus seriously weakening its ion transport ability, greatly limiting the electrochemical performance of hydrogel electronic devices in the low‐temperature environment and the actual applications 20–23 .…”