All-in-One Configured Flexible Supercapacitor for Wide-Temperature Operation and Integrated Application

The advantages of stretchable supercapacitors (SCs), such as fast charging and discharging speed, high power density, and long cycle life, have attracted the research interest of many researchers. However, conventional SCs have limited applications in energy storage devices due to their unsatisfactory environmental tolerance, easy detachment of electrodes and electrolytes, and poor stretchability. In this work, a poly(vinyl alcohol) (PVA)–(acrylic acid) (AA) double-network hydrogel electrolyte was prepared by a one-pot method, followed by in situ polymerization of aniline (PANI) to fabricate all-in-one polyaniline SCs (PANI-SCs) devices. Multiple hydrogen bonds and in situ polymerization of PANI and dimethyl sulfoxide (DMSO) endow the PANI-SCs integrated, flexible SCs with good mechanical properties and electrochemical performance in a wide temperature range. The PANI-SCs device exhibits an excellent tensile elongation strain of 413.7% and a mechanical strength of 137.1 kPa. At room temperature, the areal capacitance of the PANI-SCs device is 48.1 mF cm –2 . PANI-SCs contains a DMSO component; DMSO lowers the saturated vapor pressure of water to lower its freezing point and suppress the formation of ice crystallites and exhibits normal electrochemical performance over a wide temperature range of −80 to 100 °C. PANI-SCs drive LED lights and integrate with sensors for human health monitoring applications. Potential applications extend the development of flexible SCs in wearable electronics.