Surface engineering of M5X4 MXenes for next-gen energy solutions

초록

M5X4 MXenes represent a novel class of two-dimensional transition metal carbides, distinguished by their unique stoichiometry, high electronic conductivity, and versatile surface chemistry. These attributes render them particularly promising for high-performance energy storage applications. This review systematically explores their synthesis methodologies, structural intricacies, and electrochemical behavior across various systems, including supercapacitors, lithium-ion, sodium-ion, and zinc-ion batteries. Emphasis is placed on their dual role in ion intercalation and surface-controlled pseudocapacitive processes, which collectively contribute to superior energy density, rapid charge transport, and prolonged cycle life. Beyond their intrinsic material advantages, M5X4 MXenes offer mechanical resilience and structural adaptability, enabling seamless integration into hybrid and flexible storage platforms. However, practical implementation is currently hindered by challenges associated with large-scale fabrication. Conventional synthesis techniques often involve hazardous reagents and high resource consumption, raising concerns regarding environmental sustainability and economic feasibility. This review critically evaluates these constraints and highlights emerging low-toxicity, cost-effective, and scalable synthesis routes as viable alternatives. By juxtaposing performance metrics with production realities, the review articulates a nuanced perspective on the transformative potential of M5X4 MXenes. These materials not only surpass conventional electrode candidates in electrochemical efficacy but also serve as a foundation for nextgeneration, multifunctional energy storage technologies. Realizing their full potential, however, necessitates continued interdisciplinary efforts to refine synthesis protocols, enhance material stability, and address economic barriers, thereby paving the way for their widespread adoption in advanced energy systems.

키워드