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Nature employs supramolecular self-assembly to organize many molecularly complex structures. Based on this, we now report for the first time the supramolecular self-assembly of 3D lightweight nanocellulose aerogels using carboxylated ginger cellulose nanofibers and polyaniline (PANI) in a green aqueous medium. A possible supramolecular self-assembly of the 3D conductive supramolecular aerogel (SA) was provided, which also possessed mechanical flexibility, shape recovery capabilities, and a porous networked microstructure to support the conductive PANI chains. The lightweight conductive SA with hierarchically porous 3D structures (porosity of 96.90%) exhibited a high conductivity of 0.372 mS/cm and a larger areanormalized capacitance (C s ) of 59.26 mF/cm 2 , which is 20 times higher than other 3D chemically cross-linked nanocellulose aerogels, fast charge−discharge performance, and excellent capacitance retention. Combining the flexible SA solid electrolyte with low-cost nonwoven polypropylene and PVA/H 2 SO 4 yielded a high normalized capacitance (C m ) of 291.01 F/g without the use of adhesive that was typically required for flexible energy storage devices. Furthermore, the supramolecular conductive aerogel could be used as a universal sensitive sensor for toxic gas, field sobriety tests, and health monitoring devices by utilizing the electrode material in lightweight supercapacitor and wearable flexible devices.

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Cellulose is the most abundant renewable natural polymer on earth, but it does not conduct electricity, which limits its application expansion. The existing methods of making cellulose conductive are combined with another conductive material or high-temperature/high-pressure carbonization of the cellulose itself, while in the traditional method of sulfuric acid hydrolysis to extract nanocellulose, it is usually believed that a too high temperature will destroy cellulose and lead to experimental failure. Now, based on a new research perspective, by controlling the continuous reaction process and isolating oxygen, we directly extracted intrinsically conductive cellulose nanofiber (CNF) from biomass, where the confined range molecular chains of CNF were converted to highly graphitized carbon at only 90 °C and atmospheric pressure, while large-scale twisted graphene films can be synthesized bottom-up from CNFene suspensions, called CNFene (cellulose nanofiber–graphene). The conductivity of the best CNFene can be as high as 1.099 S/cm, and the generality of this synthetic route has been verified from multiple biomass cellulose sources. By comparing the conventional high-pressure hydrothermal and high-temperature pyrolysis methods, this study avoided the dangerous high-pressure environment and saved 86.16% in energy. These findings break through the conventional notion that nanocellulose cannot conduct electricity by itself and are expected to extend the application potential of pure nanocellulose to energy storage, catalysis, and sensing.