All-polymer ultrathin flexible supercapacitors for electronic skin

Ultrathin flexible supercapacitors (UF-SCs) are highly desired for powering electronic skin devices. Most of current UF-SCs require electrochemically inactive substrates and binders to load electro-active materials, which limit the volumetric capacitance and stability of these UF-SCs. Herein, we report an all-polymer UF-SC based on conductive polypyrrole (PPy) film, which is constructed by the dynamic network formed by rigid PPy (similar to 90 wt%) and soft polyethylene glycol (PEG, only 10 wt%) through supramolecular interactions. The network structure can effectively dissipate the destructive energy during mechanical or electrochemical deformation, making the PPy film strong and robust; and also helps to maximize the utilization of PPy, enabling the PPy film better electric conductivity and electrochemical capacitance than conventional PPy materials. After systematic optimization, we found the PEG600-PPy as the optimal electrode material, which can serve as electroactive material, current collector, and mechanical support simultaneously. Therefore, without using any substrate or current collector, these high-performance PEG600-PPy films can be directly used as electrodes for making all-polymer UF-SC. With high volumetric capacitance (547 F/cm(3)), outstanding mechanical and electrochemical stability, our all-polymer UF-SC (similar to 80 mu m in thickness, thinner than a piece of A4 paper) is a promising power device for electronic skin devices.

Automated summary

An all-polymer ultrathin flexible supercapacitor based on conductive polypyrrole film was developed, with a unique dynamic network structure formed by rigid PPy and soft PEG, resulting in high electric conductivity and capacitance. This supercapacitor showed promising performance as a power device for electronic skin devices, with high volumetric capacitance, mechanical and electrochemical stability.