Enhancing ionic conductivity, mechanical stability and electrochemical properties simultaneously by integrating POSS-PEG13.3 hybrid nanoparticles into PEO-NaClO4 solid polymer electrolytes

•A nanocomposite solid polymer electrolyte was developed utilizing a solution casting method.•At 30 °C, the composites exhibit an ionic conductivity reaching up to 1.02 × 10–4 S/cm.•The addition of POSS-PEG13.3 significantly improves the mechanical properties of the SPEs.•The nanocomposite solid polymer electrolyte demonstrates a high ion transport number.•The 70PEO-30NaClO4- 40 wt.% POSS-PEG13.3 electrolyte yielded improved battery performance. The increasing global energy demand and environmental concerns necessitate the development of sustainable energy storage solutions. Sodium-ion batteries have emerged as a promising alternative to lithium-ion batteries due to the abundance and low cost of sodium. This study investigates the impact of incorporating hybrid nanoparticles, specifically polyhedral oligomeric silsesquioxane - poly(ethylene glycol) (POSS-PEG13.3), on the performance of polyethylene oxide (PEO) - sodium perchlorate (NaClO4) based solid polymer electrolytes (SPEs). The results demonstrate that the incorporation of POSS-PEG13.3 effectively disrupts the crystallinity of the PEO matrix, as confirmed by X-ray diffraction and differential scanning calorimetry analyses. Consequently, the ionic conductivity of the SPEs increases with increasing POSS-PEG13.3 content, reaching a maximum of 1.02 × 10–4 S/cm at 30 °C for the electrolyte containing 40 wt.% of POSS-PEG13.3. Furthermore, the addition of POSS-PEG13.3 significantly improves the mechanical properties of the SPEs, enhancing their stability and durability. The ionic transference number (tion = 0.988) confirm that ions are the primary charge carriers in these electrolytes. Additionally, linear sweep voltammetry and battery discharge studies indicate a wide electrochemical stability window of 3.32 V, demonstrating the suitability of these SPEs for Na-ion battery applications. [Display omitted]