The growing popularity of smart electronics in wearables, the Internet of Things (IoT), soft robotics, and biomedical implants simultaneously demands more reliable and durable power sources. However, limitations on battery life continue to compromise reliability, prompting the search for sustainable solutions for flexible, self-powered systems. In this work, stretchable self-powered piezoelectric nanogenerators have been designed from functionalized piezoelectric nanofibers with a bioinspired coiled helical microstructure. Composed of two-dimensional (2D) Ti₃C₂T_x MXene and silver nanoparticles (AgNPs) embedded in a poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) matrix, the coiled structure achieves a mechanoelectrical energy conversion efficiency of 17%, and a power output of 6.6 mW cm⁻³ at 50% strain, twice the performance of similarly coiled structures. These improvements were attributed to the threefold increase in the piezoelectric coefficient through the addition of 1 wt% AgNPs to the P(VDF-TrFE)/MXene (0.1 wt%) and the coiled structure further enhancing β-phase formation reaching up to 70%. An electrospun mat sensor with dimensions of 2 × 3 cm generated 3 V at 1 Hz under an applied pressure of 7 kPa. The coil compact and lightweight design enables seamless integration into miniaturized electronics and wearable biomedical devices, promising a sustainable, battery-free power solution.

MXenes, a thriving class of two-dimensional (2D) transition metal carbides, nitrides, and carbonitrides, demonstrate considerable potential in diverse electrochemical energy storage applications. To leverage MXenes for high-performance sulfur-based batteries, researchers have employed various strategies to modify their properties, aiming to tackle challenges such as the notorious shuttle effect induced by soluble polysulfides, sluggish redox reaction kinetics, and substantial volume expansion during the lithiation process. This review article offers an overview of MXene modification strategies, emphasizing their significant potential in adjusting the composition, surface chemistry, and morphology to address one or more challenges specially in sulfur cathodes. We first discuss internal regulation methods of MXene, including surface group engineering, heteroatom doping, and high-entropy MXene synthesis, which have been demonstrated to enhance MXene-polysulfide interactions and facilitate polysulfide conversion. Subsequently, we provide a summary of the recent design methods and advancements made in MXene-derived and MXene-based composites, with a particular emphasis on electronic structure reconstruction at the heterointerface and their synergistic roles in Li-S batteries. Following this, we outline the utilization of MXenes to address the challenges encountered in metal-sulfur batteries beyond Li-S batteries. Concluding the review, we offer prospects for the future development of utilizing MXenes in practical sulfur-based batteries.