Ti3C2Tx MXenes reinforced PAA/CS hydrogels with self‐healing function as flexible supercapacitor electrodes

Abstract

AbstractLightweight, thin, and stretchable flexible microelectronic devices have become a new challenge for researchers. To provide power for these conformable devices, it is necessary to design the energy storage device into a flexible and stretchable structure. In this paper, a two‐step method was used to prepare a dual‐physical cross‐linked polyacrylic acid/chitosan/Ti3C2Tx(PCT) conductive hydrogel flexible electrode. The three‐dimensional (3D) porous structure not only offers a good electrical connection, but also saves the use of binder and additional current collector, which helps to enhance the electrochemical properties of electrode. The unique two‐dimensional layered structure of Ti3C2Tx enables the hydrogel electrode to withstand considerable pressure deformation without breaking, and has excellent tensile properties. The flexible electrode exhibited an excellent tensile strength of 0.083 MPa if only introduced 0.31 wt% of Ti3C2Tx with the tensile strain of 158.63% and owned remarkable self‐healing properties after injury. Thereby, the hydrogel electrode renders a maximum capacitance of 291.8 mF g−1 at 0.5 mA/g and a good cycling stability with 64.24% capacitance retention after 2000 charge–discharge cycles. This provides a research and development strategy for binder‐free, non‐toxic, and mini‐size flexible energy storage devices.