Constructing self-healing flexible supercapacitors using a graphene oxide synergistic multi-network polymer-supramolecular hydrogel electrolyte†

Hydrogels are attracting increasing interest and have great potential as electrolytes for flexible supercapacitors (FSCs) in wearable and portable electronic devices. However, for practical applications, hydrogel electrolytes are hampered by factors such as their unsatisfactory temperature tolerance, poor mechanical properties and no self-healing properties. Herein, a novel self-healing and wide temperature-resistant graphene oxide synergistic multi-network polymer-supramolecular (PAM/CMCS/PEG/GO) hydrogel electrolyte is prepared using a one-step radical polymerization method. The design of the cross-linked network structure introduces reversible dynamic interactions that allow the hydrogel electrolyte to have excellent mechanical properties and high self-healing capability. The strong hydrogen bonding in the hydrogel network significantly lowers the freezing point of water and slows down the evaporation of water at high temperatures, thus leading to reliable temperature resistance (−10–90 °C). Meanwhile, the assembled PAM/CMCS/PEG/GO hydrogel electrolyte-based FSC has a high capacitance retention rate; the capacity retention is 83.3% after 6000 charge/discharge cycles, and the capacitance of the FSC retains 92.3% of its original state after 5 cycles of cutting/self-healing.