CNT@SrTiO₃ Nanocomposites Synthesized by In Situ Reaction for a High-Performance Flexible Supercapacitor

This study presents the in situ synthesis of CNT@SrTiO₃ nanocomposite films for the development of high-performance flexible supercapacitors. The synthesis process involved the use of organic-inorganic hybrid polymers containing metal elements as precursors for thermal decomposition reaction under a reducing atmosphere. Due to the formation of chemical bonding between Ti elements and the CNTs, the interface between STO and CNT surface could provide additional active sites for ion transport and storage. Thereby, the incorporation of SrTiO₃ nanoparticles into CNTs enhanced the electrochemical performance of the resulting nanocomposite membranes. To further investigate the influence of STO content and synthesis temperature, we conducted a detailed analysis. The findings indicated that the CNT@STO film with 25% STO content, synthesized at 700 °C, and possessed optimal performance with an areal capacitance of 6682 mF·cm^-2 at 5 mV·s^-1. Furthermore, a symmetrical flexible supercapacitor assembled by two CNT@STO-25 electrodes demonstrated strong application potential in wearable devices, owing to its long cycle life, excellent flexibility, and high energy density of 430.2 μWh·cm^-2 (corresponding power density of 4.5 mW·cm^-2). Based on these results, we believe that this study provides a fresh idea for the development of novel flexible energy storage materials.