Fabrication of dual-function conductive cellulose-based composites with layered conductive network structures for supercapacitors and electromagnetic shielding

In this work, a conductive TEMPO-cellulose nanofibers(TONF)/conductive carbon black(CCB)/ Vinasse activated carbon(VAC)(TCA) composite was constructed by electrostatic adsorption, freeze-drying, and hot pressing. In this composite, a conductive TONF composite with good electrical conducting properties was constructed by electrostatic adsorption between TONF and CCB. And the conductive TONF can be used as an ideal dispersant to effectively prevent accumulation between VACs. In addition, TONF imparts TCA composites with excellent mechanical properties. Due to the layered conductive network structure formed by the effective tight stacking between the highly conductive TONF layer and the VAC, the assembled supercapacitor exhibits a high specific capacitance of 263F g−1 (672 mF cm−2), energy density of 23.8 Wh kg−1, and power density of 5.7 KW kg−1. What's more, the assembled supercapacitor can exhibit excellent cycle stability after 12,000 cycles. In addition, An intelligent electromagnetic(EMI) shielding TCA-V composite material with shape memory function was prepared by introducing a dynamically cross-linked polymer Vitrimer. In summary, TCA composites have excellent integration properties, especially electrochemical properties with good stability performance and excellent EMI shielding properties. These remarkable features make nano cellulose/carbon-matrix composites have great attraction and potential in the field of supercapacitors and intelligent EMI shielding.