Tough, self-healable, antifreezing and redox-mediated gel polymer electrolyte with three-role K3[Fe(CN)]6 for wearable flexible supercapacitors

Supercapacitors exhibiting toughness, self-healing, and high specific capacitance have practical significance for use in flexible and wearable electronic equipment. To meet these requirements, a novel multifunctional gel polymer electrolyte (GPE) consisting of polyvinyl alcohol (PVA)-sodium alginate (SA)-K3[Fe(CN)]6-Na2SO4 was prepared. In this GPE, K3[Fe(CN)]6 plays three crucial roles by serving as a carrier donor, ionic crosslinking agent and redox-active mediator. Consequently, the usual conflict between the conductivity and mechanical properties of GPEs is alleviated to some extent. In addition, the electrode specific capacitance and the energy density of the assembled supercapacitor are obviously improved because of the pseudocapacitance generated from the redox reaction of K3[Fe(CN)]6. Based on this GPE, the supercapacitor exhibits outstanding bending and stretching stabilities, significant self-healing, and anti-freezing properties. Therefore, the prepared GPE and supercapacitor are promising for application in flexible and wearable electronic equipment with complex service conditions.