Nanocellulose and Its Composites Toward Flexible Supercapacitor

Abstract Flexible wearable devices are revolutionizing the electronics industry with their lightweight, flexible, intelligent, and efficient characteristics. Flexible supercapacitors (FSCs) are promising energy storage devices for wearable electronics due to their high security, high power density, and long service life. Nanocellulose, a low‐cost and environmentally friendly material, has emerged as a promising candidate for FSC electrodes and electrolytes, owing to its degradable and renewable properties, and excellent mechanical behaviors. This review aims to provide a fresh perspective on optimizing FSCs by nanocellulose for superior energy storage. The exploration begins by detailing the preparation of various types of nanocellulose with unique structures. Subsequently, the latest research progress in crafting FSC electrodes with nanocellulose and its diverse composites, including conductive polymers, metal compounds, and carbon nanomaterials is comprehensively discussed. Additionally, gel electrolyte materials composed of nanocellulose composites are examined in detail. The previous research findings are consolidated, offering a reference point for further exploration of nanocellulose in this context.