Random interstratification of antimonene with V2CTx MXene: An electrode material with superior charge storage characteristics

Self-agglomeration and restacking of MXene layers limits their application in energy storage owing to reduced active sites availability to electrolyte ions. Thus, enhancing the number of electroactive sites in MXene while maintaining its structural stability still remains a challenge. To overcome this, we have utilized conducting and hydrophilic antimonene as a spacer in-between MXene nanosheets resulting in a heterostructure with abundant electroactive sites (1.35 mmol g- 1 @ 5 mV s-1) and enlarged electroactive surface area (ECSA990 m2g-1). As a result, MXene/antimonene composite manifests high specific capacitance of 568 F g- 1 @ 2 A g-1. To verify practical application of the fabricated electrode in energy storage, a symmetric cell was assembled in 1.0 M H2SO4 that delivered an energy density of 22.5 Wh Kg- 1 @473.4 W kg-1. Charge storage characteristics of symmetric device are well maintained with only a 11 % degradation in specific capacitance after 10000 Galvanostatic charge-discharge (GCD) cycles @ 5 A g- 1. The current study can be extended to other MXene based nanocomposites for applications in high performance portable electronics.