A flexible Zn-ion hybrid micro-supercapacitor based on MXene anode and V2O5 cathode with high capacitance

In recent years, the metal ion hybrid micro-supercapacitor (MSC) comprised of the battery-type Faradaic cathode based electrode and capacitor-type anode based electrode, can realize both high power and energy density, which becomes one of the most hottest areas of energy device. Herein, we demonstrated a zinc-ion hybrid micro-supercapacitor (ZIHMSC) by designing a Ti3C2Tx MXene based electrode as capacitor-type anode and vanadium pentoxide (V2O5) based electrode as battery-type cathode. In addition, the polyacrylamide (PAM) hydrogel where ZnSO4 dissolved was chosen as the electrolyte, which effectively avoids the security risks, unlike other hybrid MSC based on the organic electrolytes. Meanwhile, the flexible ZIHMSC also exhibits well electrochemical properties, displaying a remarkable capacitance (129 mF cm−2 under 0.34 mA cm−2), high energy density (48.9 μWh cm−2 at 673 μW cm−2) and well-cycle stability (retaining ~ 77% capacitance after 10,000 cycles). This work supports a prospective routine for constructing the new-generation flexible micro-energy storage systems.