Optimizing all-solid-state sodium-ion batteries: Insights from a P2D Model on NaSICON-based polymer–ceramic electrolyte

Rechargeable batteries are integral to modern technology, with lithium-ion batteries (LIBs) leading in portable electronics and electric vehicles. However, the abundance and global distribution of sodium have renewed interest in sodium-ion batteries (SIBs) as a sustainable alternative, particularly for stationary energy storage and applications with less stringent energy density needs. This study develops a pseudo-two-dimensional (P2D) model to investigate the performance of all-solid-state sodium-ion batteries (ASSSIBs) with hybrid polymer–ceramic electrolytes. We compare this model with a particle-resolved microstructure model to derive effective transport parameters. Our results highlight the significance of electrolyte composition and cell design to mitigate transport limitation in the electrolyte and maximize battery performance. Optimal cell design varies with C-rate, requiring lower active material fractions and more uneven particle distributions for higher rates. Optimization shows that the charge process can harness more cell capacity than discharging, suggesting a bottleneck in the discharge process. These insights guide the development of more efficient and reliable ASSSIBs, emphasizing the importance of fast-ion conducting solid electrolytes for future advancements.