Super-tough and self-healable all-cellulose-based electrolyte for fast degradable quasi-solid-state supercapacitor

Recyclable and degradable supercapacitors have promising applications for a sustainable energy storage industry. Herein, we prepare a dual-physical crosslinking (DP) carboxymethyl cellulose (CMC) hydrogel with high-toughness, healability, and electric conductivity by integrating abundant ions into the matrix. The prepared hydrogel displays a maximum compressive fracture stress of 4.42 MPa, fast healing in five seconds, and full degradation within eight days. Moreover, the fabricated supercapacitor shows high specific capacitance (309 F g−1) and volumetric capacitance (2.60 F cm−3). The supercapacitor achieves a healing efficiency of 93.9 % after five cuttings, and exhibits a cycling stability of 84.6 % capacitance retention after 1000 cycles. These merits ensure that the all-cellulose-based supercapacitor can operate in case of sudden collision and deformation, which contribute to reducing the environmental hazards from supercapacitor's preparation to its abandonment. A dual-physical crosslinking strategy for the fabrication of super-tough, self-healable, and fast degradable CMC hydrogel as quasi-solid-state electrolyte with outstanding electrochemical properties. [Display omitted] •Fully degradable all-cellulose electrolytes are fabricated as supercapacitors.•The supercapacitors combine superior mechanical and electrochemical performance.•Dual-physical networks provide its strength, self healing, and ions conduction.•A route avoids petrochemical polymers, chemical crosslinking agents, and UV light.