Recent progress of stretchable MXene based micro-supercapacitors

The rapid development of wearable electronics has stimulated the urgent demand for compatible, miniaturized energy storage devices. As one of the most promising candidates, micro-supercapacitors (MSCs) have attracted significant attention, owing to their high power densities, long operation life, and fast charge/discharge rate. In comparison to conventional, rigid MSCs, deformable MSCs are attracting more and more attention for their superior tolerance to various deformations, including stretching, bending, and twisting, guaranteeing smooth operation of the wearable electronics. MXenes, a class of emerging two-dimensional transition metal carbonitrides/nitrides, have metallic conductivity, high specific surface area, good hydrophilicity, and surface chemical tunability, showing great potential as electrode material for MSCs. In this paper, the recent progress, focused on the MXene-based, stretchable MSCs with fiber-shaped, planar configuration, is systematically summarized. Moreover, the key challenges and prospects of MXene-based, stretchable MSCs for practical application are discussed, which are critical for further development of them.