Scalable One-Step Microfluidic Spinning of a Fibrous Supercapacitor with Double Helical Electrodes and Integrated Electrolyte–Electrode Interfaces

It is highly desired to develop continuous and scalable fabrication strategies for fibrous supercapacitors (FSCs) with helically structured electrodes, and the comprehensive performance, including long-term stability and operational safety, of the obtained devices is simultaneously desired to be optimized. In this work, we develop a one-step rotating microfluidic spinning technique for continuously preparing the CMC@MXene/PEDOT:PSS/CMC fibrous supercapacitor (CMC@MPC FSC) with helical structured electrodes and integrated electrode–electrolyte interfaces, which ensures the excellent ion migration capability, long-term stability, and operational safety of the obtained FSC. Therefore, the CMC@MPC FSC presents high energy storage capabilities including high volumetric capacitance (6.21 F cm–3), high energy density (3.35 mWh cm–3), high power density (50.01 mW cm–3), high rate capability (83.90% capacitance retention at 50 mA cm–3), and excellent electrochemical durability and stability, endowing it with great potential for wearable energy storage application, especially in the energy harvesting systems where high charge–discharge speed and frequency are required. This work presents a scalable, one-step approach for fabricating high-performance, all-in-one FSCs and lays the foundation for the next generation of flexible, integrated energy storage systems in smart textile technologies.