Ultrahigh Energy Charge–Discharge Efficiency in Olefinic Elastomer with POSS Cage‐Linking Construction (Adv. Mater. Technol. 15/2025)

Polymer Dielectrics To meet the demands of miniaturized and high-frequency electronics, in article number 2500020, Lixin Xu, Huijian Ye, and co-workers design a thiol-functionalized POSS cage with a wide-bandgap of 5.22 eV as a crosslinker in the elastomer via click chemistry. The POSS/SBS composite with its cage architecture traps charge carriers, suppressing leakage current, and achieves an ultrahigh charge–discharge efficiency of 97.5% over 105 cycles. This breakthrough enables reliable energy storage for next-generation flexible capacitors.