Multifunctional roles of MXenes in flexible lithium–sulfur batteries: Mechanistic insights, computational perspectives, and future standards

The growing demand for wearable electronics and smart textiles has intensified research into flexible, miniaturized, high-performance, and safe energy storage devices. Lithium-sulfur (Li–S) batteries, with their high theoretical energy density supported by sulfur’s multielectron chemistry and cost-effectiveness, are highly promising, yet they face critical bottlenecks. These challenges include low long-cycle capacity retention and inadequate cycling durability during bending. Conventional materials such as graphene and conductive polymers fall short in interface stability or scalable synthesis, failing to balance electrical conductivity with mechanical strength simultaneously. MXene emerges as a breakthrough, offering metal-grade conductivity, tunable surface chemistry, abundant functional groups, and exceptional mechanical resilience. Its layered structure not only anchors polysulfides but also withstands repeated deformations. This review systematically examines the design strategies for Li–S batteries that integrate flexibility, high energy density, and cycling stability. Firstly, synthesis, structure, properties, and analysis of advantages of MXene used in Li–S batteries are summarized. Subsequently, computational and simulation approaches are employed to analyze MXene’s role in addressing shuttle effects and lithium dendrite growth. Applications of MXene-based materials in various components of flexible Li–S batteries are then discussed. Finally, insights are provided on challenges and future developments for MXene-based flexible Li–S batteries.