Enhancing Capacitance Performance of Ti3C2Tx MXene as Electrode Materials of Supercapacitor: From Controlled Preparation to Composite Structure Construction.

Highlights: The traditional and novel etching methods are summarized and compared, especially fluorine-free method. The methods for accelerating exfoliation of Ti3C2Tx are classified. The energy storage mechanisms of Ti3C2Tx in different electrolytes are compared. Based on energy storage mechanisms, the influencing factors of morphology and surface functional groups are discussed. In response to the problems of the Ti3C2Tx, strategies for improving capacitance from structure modulation to composite structure construction are summarized and compared.Ti3C2Tx, a novel two-dimensional layer material, is widely used as electrode materials of supercapacitor due to its good metal conductivity, redox reaction active surface, and so on. However, there are many challenges to be addressed which impede Ti3C2Tx obtaining the ideal specific capacitance, such as restacking, re-crushing, and oxidation of titanium. Recently, many advances have been proposed to enhance capacitance performance of Ti3C2Tx. In this review, recent strategies for improving specific capacitance are summarized and compared, for example, film formation, surface modification, and composite method. Furthermore, in order to comprehend the mechanism of those efforts, this review analyzes the energy storage performance in different electrolytes and influencing factors. This review is expected to predict redouble research direction of Ti3C2Tx materials in supercapacitors. [ABSTRACT FROM AUTHOR]