3D MXene/ENR hybrid electrodes with enhanced mechanical stability for flexible supercapacitors

Ti₃C₂T_xMXene-based electrodes have attracted significant attention as promising candidates for flexible supercapacitors owing to their high electrical conductivity and mechanical flexibility. However, insufficient ion accessibility and limited structural tunability impede charge transport and active site utilization, thereby reducing energy storage performance. Here, a CaCO₃-template-assisted strategy was employed to fabricate 3D MXene-S-ENR composite electrodes, yielding a porous architecture. The sacrificial CaCO₃ particles acted as spacers to expand the Ti₃C₂T_xMXene interlayer spacing, forming an interconnected 3D framework that facilitated ion transport, exposed more active sites, and enhanced mechanical stability. With an optimized template amount of 0.044 g, the electrode achieved a specific capacitance of 283.44 F·g^-1at 0.2 A·g^-1and retained 86% of its capacity after 2000 charge-discharge cycles at 2 A·g^-1. It also maintained over 96% of its capacitance under 30% tensile strain and 79.9% after 300 stretching cycles. This approach provides a scalable route to fabricating mechanically stable, high-performance Ti₃C₂T_xMXene-based electrodes for flexible energy storage.