Synergistic nanocomposite polymer electrolytes for advanced all-solid-state sodium-ion batteries

Polymer solid composite electrolyte (PSCE) has gained significant attention due to its superior ion conductivity and compatibility with electrodes compared to inorganic solid-state electrolytes, as well as its better safety compared to liquid electrolytes. In this study, Na3Zr2Si2PO12 (NZSP) nanoparticles are synthesized with polyethylene oxide (PEO) and sodium percarbonate (SPC)-based PSCE. The resulting material is evaluated for its application performances in all-solid-state sodium-ion batteries (ASSBs). The addition of Na3Zr2Si2PO12 filler reduces the polymer matrix's crystallinity and decreases the formation of sodium dendrites. As a result, the PSCE delivers an enlarged electrochemical window stability of 4.8 V and improved ion conductivity that can reach as high as 2.6 x 10-4 SCm- 1. When applied in ASSBs, the resulting PSCE shows a high first discharge capacity of 75.4 mAh g- 1 at 0.2C and a promising faradaic efficiency of 97% (for 100 cycles). These results indicate that PEO-SPC-NZSP based PSCE can be significantly improved by adding Na3Zr2Si2PO12 filler, thus enabling its practical application as a form of energy storage.