Developing two-dimensional titanium carbide (MXene) multilayer films with combing high conductive and resistant to mechanical deformations through solution-based layer-by-layer (LbL) assembly still remains a challenge. Because recent research efforts all used the polyelectrolytes to LbL assemble the MXene multilayer to achieve a high mechanical strength at the expense of conductivity. Here, we report a strategy of using a small molecule of tris(2-aminoethyl) amine (TAEA) for the LbL assembly of MXene multilayers onto a wide range of substrates from planar, fiber to 3D porous aerogel and foam. In the LbL assembly process, the small-molecule TAEA as the pillars form small gaps in-between adjacent MXene flakes, resulting in a face-to-face quasi-intimate dense contact. The pillaring effect expanded the interlayer of MXene layers by only 1.03 Å, and also reinforced the interconnection between MXene flakes to enhance the interface strain for LbL MXene films. To our best knowledge, the TAEA-pillared MXene multilayers show the highest electronic conductivity of 7.3 × 104 S m-1 among the MXene multilayers produced by LbL assembly. We also first reported a compressible 3D MXene-based hybrid with a highly reversible conductivity with a normalized resistance of 1.23 even after 80% compressible strain. Additionally, the TAEA-pillared MXene multilayers as the electrodes for flexible all-solid-state supercapacitors show highly practical volumetric capacitance of 583 F cm-3 and an integrated high energy density of 3.0 Wh L-1 corresponding to a power density of 4400 W L-1. Our strategy opens the way to construct high conductive MXene multilayers for structural energy storage, wearable electronics, and more, and also provide possibility to fabricate other types of 2D material multilayers.

Layer-by-layer assembly of pillared MXene multilayers for high volumetric energy storage and beyond

2019 Spring National Meeting

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