Y.Y. Zhu, J.X. Ma, P. Das, S. Wang, and Z.-S. Wu*
Small Methods, 2023, 7.
DOI: 10.1002/smtd.202201609 [PDF]
As an emerging class of two-dimensional materials, MXene exhibits broad prospects in the field of supercapacitors (SCs). However, the working voltage of MXene-based SCs is relatively limited (typically ≤ 0.6 V) due to the oxidation of MXene electrode and the decomposition of electrolyte, ultimately leading to low energy density of the device. To solve this issue, high-voltage MXene-based electrodes and corresponding matchable electrolytes are developed urgently to extend the voltage window of MXene-based SCs. Herein, we present a comprehensive overview and systematic discussion regarding the effects of electrolytes (aqueous, organic, and ionic liquid electrolytes), asymmetric device configuration, and material modification on the operating voltage of MXene-based SCs. We take a deep dive into the latest advances in electrolyte design, structure regulation and high-voltage mechanism of MXene-based SCs. Finally, we outline and discuss in depth the future perspectives on high-voltage MXene-based SCs and their possible development directions, providing new insights for the rational design and realization of advanced next-generation MXene-based electrodes and high-voltage electrolytes.