Fabrication of metal-organic framework@cellulose nanofibers/reduced graphene oxide-Vitrimer composite electrode materials with shape memory for supercapacitors

Abstract

With the rapid development of flexible electronic devices towards small, light, and high-performance, people's requirements for electrode materials that affect energy storage devices are also increasing. It is crucial to prepare composite electrode materials with excellent comprehensive performance through reasonable design. This study successfully prepared a novel Ni-metal-organic framework (Ni-MOF) @ cellulose nanofibers (CNF)/reduced graphene oxide (rGO) -Vitrimer (MOF@CNF/rGO-V) electrode material through freeze-drying and solvent-thermal methods. In the hybrid, CNF not only prevents the stacking of rGO but also serves as a flexible substrate for loading Ni-MOF, while the porous structure of the CNF aerogel provides numerous channels for electrolyte ions to store and transport. The presence of Ni-MOF loaded on the conductive substrate contributes to a high pseudo-capacitance, ultimately yielding a composite material with a high specific capacitance (189.9 F g−1). Furthermore, when the composite was assembled into a symmetric supercapacitor device, it exhibited an energy density of 35.61 W h kg−1 at a power density of 641.07 W kg−1 and a remarkable cycling stability of up to 96.59% after experiencing 20,000 cycles. In addition, the introduction of Vitrimer successfully prevented electrode material detachment or fracture during use while maintaining excellent electrochemical and mechanical properties, imparting shape-memory functionality. The as-fabricated MOF@CNF/rGO-V composite electrode material holds significant promise and attractiveness in the field of flexible wearable electronics.