MXene films are attractive for advanced supercapacitor electrodes requiring high volumetric energy density due to their high redox capacitance combined with extremely high packing density. However, the self‐restacking of MXene flakes unavoidably decreases the volumetric performance, mass loading, and rate capability. Herein, a simple strategy is developed to prepare a flexible and free‐standing modified MXene/holey graphene film by filtration of the alkalized MXene and holey graphene oxide dispersions, followed by a mild annealing treatment. After terminal groups (—F/—OH) are removed, the increased proportion of Ti atoms enables more pseudocapacitive reaction. Meanwhile, the embedded holey graphene effectively prevents the self‐restacking of MXene and forms a high nanopore connectivity network, which is able to immensely accelerate the ion transport and shorten transport pathways for both ion and electron. When applied as electrode materials for supercapacitors, it can deliver an ultrahigh volumetric capacitance (1445 F cm−3) at 2 mV s−1, excellent rate capability, and high mass loading. In addition, the assembled symmetric supercapacitor demonstrates a fantastic volumetric energy density (38.6 Wh L−1), which is the highest value reported for MXene‐based electrodes in aqueous electrolytes. This work opens a new avenue for the further exploration of MXene materials in energy storage devices.

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MXene (Ti3C2Tx) is a new 2D material with both hydrophilicity and high electrical conductivity, and it has shown promise in smart electronic devices. Reported herein is a homogeneous MXene film actuator with high electrical conductivity triggered by moisture gradients. The actuator is highly sensitive to moisture and undergoes deformation, with the maximum bending angle as high as 155° at a relative humidity difference of 65 %. Several analysis methods show that the humidity drive and large deformation of the MXene film occur in situ by asymmetric expansion of the bilayer structure. The combination of deformation and electrical conductivity makes this film applicable to flexible excavators, electrical switches, and other fields, applications that are difficult to achieve directly by using other 2D materials. More importantly, this work further expands the new application range of MXene materials and provides new opportunities for building the next generation of high‐conductivity smart actuators.