Ultrastable Polypyrrole Stabilized by Hyper-Cross-Linked Poly(styrene- <i>co</i> -divinylbenzene) for Long-Cycle Supercapacitor Applications

Polypyrrole (PPy) is a promising conducting polymer for supercapacitor electrodes, but its structural degradation during repeated cycling limits its long-term stability. Here, we report the design of a composite based on PPy chemically stabilized by hyper-cross-linked poly-(styrene-<i>co</i>-divinylbenzene) (HPStDVB) microparticles (PPy/HPStDVB) working as a scaffold. This composite possesses a more compact structure, preventing interruptions in the conjugation of PPy. As a result, the PPy/HPStDVB electrode exhibits remarkable electrochemical durability, maintaining its capacitance over 20,000 charge-discharge cycles and demonstrating a dominant capacitive contribution (77.3%) in the hybrid supercapacitor cell. These more stable electrochemical properties of PPy on HPStDVB arise from the interactions of the HPStDVB backbone with PPy, resulting in a more stable structure due to less dynamic functional groups. This study introduces a simple yet efficient strategy for mechanically reinforced conducting-polymer electrodes, providing a new route toward durable, high-performance supercapacitors.