MXenes in Advanced High‐Performance Energy Storage Technologies: Synthesis, Properties, Applications, and Challenges

ABSTRACT The global transition to renewable energy is bottlenecked by the efficiency, safety, and environmental limitations of conventional electrochemical storage. MXenes are two‐dimensional transition‐metal carbides and nitrides. They offer a transformative alternative due to their exceptional electrical conductivity and tunable surface chemistry. However, their commercial viability is severely hindered by key pain points: hazardous synthesis routes, oxidative instability, and nanosheet restacking that restricts ion transport. Despite a rapidly expanding body of literature, existing reviews predominantly evaluate MXene synthesis and device performance in isolation. This review provides a unified framework focused specifically on the intersection of green synthesis and biomimetic architecture. This approach establishes a unique perspective on how nature‐inspired designs can simultaneously resolve MXene's structural bottlenecks and broader environmental concerns. This article systematically evaluates the transition from toxic, top‐down etching to scalable, fluoride‐free, and bio‐derived synthesis methods. We highlight how utilizing agricultural biomass achieves competitive electrochemical performance while maximizing cost‐effectiveness. Furthermore, we rigorously analyze how biomimetic configurations (nacre‐inspired brick‐and‐mortar layering, honeycomb porosity, and wood vascular channels) directly mitigate restacking. These designs significantly enhance charge transport, yielding superior specific capacitance, energy density, and cyclic stability. The integration of conductive additives and mathematical modeling frameworks further grounds these structural improvements in theoretical optimization. Finally, by confronting ongoing challenges in economic feasibility and manufacturing scalability, this review outlines commercial implementation pathways for electric vehicles and grid storage. These pathways are uniquely augmented by recent advances in artificial intelligence and circular economy principles and establish a comprehensive roadmap for next‐generation, sustainable MXene technologies.