Fabrication of MXene/cellulose composite-based flexible supercapacitor: Synthesis, properties, and future perspectives

MXenes have attracted considerable research interest in the field of energy storage due to their unique structure and favourable surface functional group properties. Recent efforts are focused extensively on synthesizing MXene composites for fabricating ideal electrode materials for energy storage applications. To fully exploit the characteristic features of MXene nanosheets and to ensure superb mechanical properties, cellulose is frequently used in combination with MXene to design high-potential functional nanocomposites. Cellulose serves as a promising reinforcing filler and flexible substrate due to its excellent mechanical strength. Its one-dimensional filamentous structure minimizes insulating contacts between 2D materials, enhancing both supercapacitive and mechanical properties. Furthermore, the 3D printing of micro-supercapacitors (MSCs) using MXene/cellulose inks yields desired printed interdigitated patterns with higher geometric accuracy, resulting in superior mechanical strength and capacitive performance. In this article, we present a comprehensive and timely review of recent research efforts and their outcomes related to the fabrication of flexible supercapacitors (SCs) based on MXene/cellulose composites. The scope extends to the fabrication of MXene/cellulose MSCs and electrodes that are wearable or free-standing. The initial sections of the article delve into the current synthesis methodologies for MAX phase and MXene, highlighting structural variations resulting from different synthesis procedures. Subsequently, we discuss the synthesis procedures for MXene/cellulose composites, the fabrication of MXene/cellulose based SCs, and their performance. Towards the end, we address existing research gaps and provide insights into future perspectives regarding MXene/cellulose SCs, drawing from the latest research findings. This review underscores the pivotal role played by MXene/cellulose composites in advancing the field of energy storage. © 2024 Elsevier Ltd.