High-performance all-solid-state flexible asymmetric supercapacitors composed of PPy@Ti3C2Tx/CC and Ti3C2Tx/CC electrodes

Supercapacitors have attracted enormous attention for energy storage in the past years. In this study, an all-solid-state flexible asymmetric supercapacitor was assembled with PPy@Ti3C2Tx composite material deposited on carbon cloth (CC) as the positive electrode (PPy@Ti3C2Tx/CC) and the CC with Ti3C2Tx (CC) as the negative electrode (Ti3C2Tx/CC) in the absence of any binder. The PPy@Ti3C2Tx/CC composite electrode was prepared by facile one-step electrochemical co-deposition at a suitable concentration ratio of Ti3C2Tx nanosheets and pyrrole monomers in an aqueous solution. The excellent conductivity of Ti3C2Tx and the porous structure of PPy@Ti3C2Tx/CC composite electrode greatly facilitated the charge' transfer and ions' diffusion across the composite films, leading to better utilization of the active materials inside the composite films. As a result, the all-solid-state flexible binder-free PPy@Ti3C2Tx/CC//Ti3C2Tx/CC asymmetric supercapacitor exhibited a large operating voltage of 1.2 V, high energy density of 15.7 Wh kg(-1) at the power density of 620.8 W kg(-1), and excellent cycling stability (88.7% capacitance retention after 5000 cycles). This work presented a simple and efficient approach to prepare composite electrodes and fabricated all-solid-state asymmetric supercapacitors with high electrochemical performances for flexible electronics.

Automated summary

In this study, a flexible asymmetric supercapacitor was assembled using PPy@Ti3C2Tx composite material as the positive electrode and Ti3C2Tx as the negative electrode without any binder. The composite electrode exhibited excellent conductivity and porous structure, facilitating charge transfer and ions diffusion, resulting in improved utilization of active materials. The all-solid-state asymmetric supercapacitor showed high energy density, large operating voltage, and outstanding cycling stability, providing a promising approach for flexible electronics.