Ti₃C₂T_<i>x</i> MXene-Reduced Graphene Oxide Composite Electrodes for Stretchable Supercapacitors.

The development of stretchable electronics requires the invention of compatible high-performance power sources, such as stretchable supercapacitors and batteries. In this work, two-dimensional (2D) titanium carbide (Ti3C2Tx) MXene is being explored for flexible and printed energy storage devices by fabrication of a robust, stretchable high-performance supercapacitor with reduced graphene oxide (RGO) to create a composite electrode. The Ti3C2Tx/RGO composite electrode combines the superior electrochemical and mechanical properties of Ti3C2Tx and the mechanical robustness of RGO resulting from strong nanosheet interactions, larger nanoflake size, and mechanical flexibility. It is found that the Ti3C2Tx/RGO composite electrodes with 50 wt % RGO incorporated prove to mitigate cracks generated under large strains. The composite electrodes exhibit a large capacitance of 49 mF/cm2 (∼490 F/cm3 and ∼140 F/g) and good electrochemical and mechanical stability when subjected to cyclic uniaxial (300%) or biaxial (200% × 200%) strains. The as-assembled symmetric supercapacitor demonstrates a specific capacitance of 18.6 mF/cm2 (∼90 F/cm3 and ∼29 F/g) and a stretchability of up to 300%. The developed approach offers an alternative strategy to fabricate stretchable MXene-based energy storage devices and can be extended to other members of the large MXene family.