Hygroscopic chemistry enables fire-tolerant supercapacitors with a self-healable “solute-in-air” electrolyte

• Main Authors: Xia, Huarong, Lv, Zhisheng, Zhang, Wei, Wei, Jiaqi, Liu, Lin, Cao, Shengkai, Zhu, Zhiqiang, Tang, Yuxin, Chen, Xiaodong
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Science::Chemistry::Physical chemistry::Electrochemistry; Engineering::Materials::Energy materials; Li‐Ion Batteries; Dual-Ion Batteries; Deep Cycling Batteries
• Online Access: https://hdl.handle.net/10356/161506
• Institution: Nanyang Technological University

High-temperature-induced fire is an extremely serious safety risk in energy storage devices; which can be avoided by replacing their components with nonflammable materials. However; these devices are still destroyed by the high-temperature decomposition; lacking reliability. Here, a fire-tolerant supercapacitor is further demonstrated that recovers after burning with a self-healable "solute-in-air" electrolyte. Using fire-tolerant electrodes and separator with a semiopen device configuration; hygroscopic CaCl2 in the air ("CaCl2 -in-air") is designed as a self-healable electrolyte; which loses its water solvent at high temperatures but spontaneously absorbs water from the air to recover by itself at low temperatures. The supercapacitor is disenabled at 500 °C; while it recovers after cooling in the air. Especially; it even recovers after burning at around 647 °C with enhanced performance. The study offers a self-healing strategy to design high-safety; high-reliability; and fire-tolerant supercapacitors; which inspires a promising way to deal with general fire-related risks.