Recent Progress in MXene-Based Supercapacitors: From Synthesis and Surface Engineering to Next-Generation Applications

) above 1500 F/g, energy densities close to 80 Wh/kg, power densities greater than 10 kW/kg, and capacitance retention over 90% after 10,000 cycles. Mechanistic insights show that electric double-layer capacitor (EDLC) and pseudocapacitive ion intercalation and surface redox reactions function together to control charge storage and self-discharge characteristics. This review integrates synthesis methods, charge storage mechanisms, and performance correlations, which emphasize new applications in SCs and wearable electronics. MXenes demonstrate their potential as a platform for advanced energy storage systems (ESSs) through their future development capabilities, which enable multifunctional device integration, structural stabilization, and scalable fabrication.