Simple Synthesis of Flower-like Manganese Dioxide Nanostructures on Cellulose Nanocrystals for High-Performance Supercapacitors and Wearable Electrodes

This work first reports cellulose nanocrystal/manganese dioxide (CNC-MnO2) electrode composites with flower-like MnO2 nanostructures via facile one-step in situ controlled synthesis. The denser flower-shaped nanostructures of CNC-MnO2 composites improved the electrolyte/electrode contact interface, providing nanochannels for ions diffusion that enhanced both electrolyte infiltration and active material utilization. A large specific capacitance of 306.3 F g–1 with high energy density was achieved due to good cycling stability and ultralow resistance. Moreover, the CNC-MnO2 composites were successfully assembled into flexible solid-state supercapacitors with good electrochemical performance, excellent bending stability, and light up a commercial light-emitting diode. This study provides a simple approach to combine a CNC-MnO2 composite electrode with commercial textile and conductive polymers (e.g., polypyrrole) to produce wearable electronic/energy devices.