Paper-roll-pencils inspired self-assembled multilayer interwoven nanocellulose supercapacitor electrode enables cross-scale stress impedance coupled with electrochemical stability

The practical application of flexible supercapacitors is often constrained by the critical contradiction between structural disintegration of electrode materials under mechanical deformation and deterioration of electrochemical performance. Inspired by the multilayer wrapping structure of paper-roll-pencils, we propose a self-assembled multilayer interwoven electrode architecture. In this design, bacterial cellulose (BC) forms a multilayered outer scaffold via alternating winding, while polydopamine (PDA) enhances interfacial adhesion and electronic coupling between nitrogen-doped graphene (N-rGO). A continuous polypyrrole (PPy) pseudocapacitive layer further encapsulates the structure to form a conductive network, collaboratively forming a continuous cross-interface transport channel from nanoscale to microscale. This unique electrode architecture simultaneously enables stress-gradient buffering and electrochemical stability regulation under mechanical load. As a result, the electrode retains 96.3 % of its capacitance after 10,000 charge-discharge cycles and ultrasonic agitation (40 kHz/200 W). This work offers a novel strategy for constructing flexible energy storage electrodes with integrated cross-scale stress impedance and high electrochemical durability.