Titanium Carbide MXene and Silver Nanowire Composite Ink for Transparent Flexible Printed Micro‐Supercapacitors

Micro‐supercapacitors ( m ‐SCs) are a competent power source for flexible and transparent electronics due to their compact and adaptive design. However, high‐performance transparent m ‐SCs require an optimum balance between transparency and storage capacity. Herein, a composite of titanium carbide (Ti 3 C 2 T x ) and silver nanowires (Ag NWs) is proposed as electrodes for flexible and transparent m ‐SCs. This composite is synthesized in the form of a printable ink for direct ink writing (DIW) of the m ‐SC using poly(3,4‐ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) as the conductive binder. The concentration of the Ag NWs, Ti 3 C 2 T x , and PEDOT:PSS in the ink is optimized to ensure high optical transparency, flexibility, and electrochemical performance of the m ‐SC. The optimized printed m ‐SC exhibits an areal capacitance of 8.34 mF cm −2 and a transparency of ≈82% (at 550 nm) resulting in a high figure of merit of 15.1 F S −1 cm −2 . It also shows high mechanical stability by retaining ≈97% of its original capacitance in various bent positions. Printing of an m ‐SCs array is demonstrated in a single step by utilizing DIW. This array is used to power a surface‐mount display LED. The obtained results for the developed m ‐SC promise its high suitability for futuristic, fully wearable, and invisible electronics.