MXenes for Supercapacitor Applications

Abstract

Owing to their unique physicochemical properties, MXenes, a relatively new class of 2D transition metal carbides, nitrides, and carbonitrides, have emerged as promising electrode materials for next-generation supercapacitors. This chapter provides a comprehensive overview of the synthesis, properties, and applications of MXenes in supercapacitor systems. A discussion of various synthesis strategies, including top-down methods (hydrofluoric acid, alkali, salt, and electrochemical etching) as well as bottom-up techniques (chemical vapor deposition), is given to highlight their influence on MXene structure and performance. The chapter explores the electrical, mechanical, and chemical properties of MXenes, emphasizing their modulation through surface functional groups. Further, it explores the application of MXenes for electric double-layer capacitors (EDLCs), pseudocapacitors, and hybrid systems, both in pristine and composite forms. Specific emphasis is on composites with carbonaceous materials, polymers, metal oxides, and sulfides to enhance electrochemical performance and address the restacking issue in MXenes. The Charge storage mechanisms in MXenes in different electrolytes—acidic, basic, and neutral—have also been discussed. Finally, the chapter outlines the challenges associated with synthesis scalability and material stability, and proposes future research direction for advancing the MXene-based supercapacitors. © 2026 Scrivener Publishing LLC.