Facile manufacturing solutions for ultra-durable flexible MXene micro-supercapacitors in 8-inch scale

The increasing demand for portable and wearable electronic devices has intensified the need for flexible and miniaturized energy storage solutions. Micro-supercapacitors (MSCs) have emerged as promising candidates due to their high power density, rapid charge–discharge capabilities, and long cycle life. Among various materials, MXenes-two-dimensional transition metal carbides and nitrides-stand out for their exceptional electrical conductivity and tunable surface chemistry. However, scalable fabrication of MXene-based flexible MSCs (fMSCs) remains a challenge. This work presents a facile method for the large-scale production of MXene-based fMSCs, enabling the fabrication of up to 100 devices in a single step. Our approach addresses the limitations of current techniques by offering an efficient and scalable solution that ensures high yield and mechanical robustness. We encountered electrochemical performance degradation during repetitive bending due to weak durability when directly fabricating photomasks onto PI films. This issue was mitigated by introducing a polymer buffer layer, resulting in an increase in volumetric capacitance from 1,093.1F cm −3 for MXene alone fMSCs to 1,487.7F cm −3 for BL-MXene fMSCs (MXene flexible micro-supercapacitors with a buffer layer). Additionally, capacitance retention improved significantly from 24.4 % to 90.3 % after 10,000 bending cycles. Importantly, our findings reveal that using the same material (PVA) for both the buffer layer and the electrolyte significantly enhances device performance and durability. This approach not only benefits MXene-based flexible supercapacitors but also has broad implications for the wider field of supercapacitor research. Improving performance through material compatibility can lead to more efficient and robust energy storage solutions, advancing flexible energy storage devices for industrial and commercial applications.