High Fire‐Safety and Multifunctional Eutectogel for Flexible Quasi‐Solid‐State Supercapacitors
Qingtao Zeng, Xuejun Lai, Hongqiang Li, Zhong‐Hua Chen, Xingrong Zeng, Liqun Zhang
Abstract
Abstract The preparation of high‐performance and fire‐safe electrolytes for flexible quasi‐solid‐state supercapacitors is challenging. In this work, a novel fire‐safe and multifunctional deep eutectic solvent gel (DESG) is fabricated using acrylic acid and urea as hydrogen bond donors and choline chloride as a hydrogen bond acceptor. DESG shows a high ionic conductivity (0.552 S m −1 ), good electrochemical performance (specific capacitance: 106.8 F g −1 ), and a wide operating temperature range (−20–90 °C), being a promising candidate for flexible solid‐state supercapacitors. Furthermore, it exhibits a good thermoelectric conversion capability (Seebeck coefficient: 1.56 mV K −1 ), being ideal for thermoelectric capacitors and fire‐warning sensors. The prepared DESG rapidly self‐extinguishes after removal from fire, reaching a limiting oxygen index value of 38.0% and demonstrating its excellent flame retardancy. In addition, DESG has a good self‐healing performance (healing efficiency of 84.3%). The work provides new insights into the preparation and application of high fire‐safety and multifunctional eutectogels for flexible quasi‐solid‐state supercapacitors.