Achieving high-rate capacitance of multi-layer titanium carbide (MXene) by liquid-phase exfoliation through Li-intercalation

•The exfoliation efficiency has been improved through Li-intercalation between Ti3C2Tx layers in isopropyl alcohol.•SEM and AFM confirm the delamination of multi-layer Ti3C2Tx into few-layer nanosheets.•The delaminated Ti3C2Tx exhibits excellent capacitive performance and superior cycling stability even at high scan rates.

The stacks of multi-layer Ti3C2Tx and other types of MXene materials limit their electrochemical performance. Herein, we report a facile exfoliation technique to improve the exfoliation efficiency through Li-intercalation into Ti3C2Tx interlayers in isopropyl alcohol (IPA) with LiOH as intercalant. This de-intercalation method presented here not only effectively delaminates the stacked Ti3C2Tx multi-layers into separate few-layer MXene sheets, but also achieves high-rate supercapacitive performance of Ti3C2Tx electrode. The as-produced delaminated Ti3C2Tx shows highly improved electrochemical capacitive properties from 47 to 115 F g− 1 at 200 mV s− 1. Even at extremely high scan rate of 1000 mV s− 1, a specific capacitance of 82 F g− 1 is still obtained. The high-rate capability can be attributed to improved ions accessibility into the few-layer structures. This study offers a new and simple exfoliation pathway for MXenes materials to exploit their full potential in energy storage applications.

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