VS4 nanoarrays pillared Ti3C2Tx with enlarged interlayer spacing as anode for advanced lithium/sodium ion battery and hybrid capacitor

Aiming to improve the sluggish ion insertion/extraction at the battery-type anode in lithium-ion/sodium-ion hybrid capacitor (LIC/SIC), herein, a VS4@L-Ti3C2Tx composing of VS4 nanoarrays and MXene with enlarged interlayer spacing is developed through a facile hydrothermal approach. Benefiting from the merits of building blocks, the VS4@L-Ti3C2Tx based lithium-ion half-cell exhibits superior specific capacity (1328 mAh g-1 after 170 cycles at 0.1 A g-1), rate performance (808 mAh g-1 after 10 cycles at 20 A g-1) and cycling stability (721 mAh g-1 after 500 cycles at 1.0 A g-1), surpassing most of the reported VS4 based counterparts. The sodium-ion half-cell with VS4@L-Ti3C2Tx anode also shows good performances. Moreover, LIC and SIC based on VS4@LTi3C2Tx anodes deliver high energy densities of 122.5 Wh kg- 1 and 117.0 Wh kg- 1 at a low power density 100.3 W kg- 1, respectively. Additionally, they exhibit excellent cycling lifespans with capacity retention of 60% after 20000 cycles for LIC at a high current rate 1.0 A g-1, outperforming most of the reported analogues. This study may shed light on the development of other layered anode materials for energy storage devices.

Automated summary

In this study, a VS4@L-Ti3C2Tx composed of VS4 nanoarrays and MXene with enlarged interlayer spacing was synthesized via a facile hydrothermal method for lithium-ion/sodium-ion hybrid capacitor. The lithium-ion half-cell and sodium-ion half-cell based on this material exhibited superior electrochemical performance and cycling stability. Furthermore, the LIC and SIC based on this material also showed high energy densities and excellent cycling stability.