Cellulose-based separator modified with SrTiO 3 enhancement layer for novel high-performance sodium-ion batteries

Abstract Owing to the mismatch between existing commercial separators and sodium-ion batteries, the development of novel separator materials tailored for sodium-ion systems is of critical importance. Herein, a modified cellulose-based separator (denoted as STO@HCMCF) with SrTiO 3 enhancement layer was designed by the in-situ chemical precipitation method, which significantly improved electrolyte wettability and effectively regulated interfacial interactions in the battery. These characteristics feature the separator to more pathways for Na + transport, thereby significantly accelerating the transportation and deposition of Na + . The Prussian blue/sodium (PB/Na) cell assembled with the STO@HCMCF separator exhibited a superior capacity of 96.6 mAh g −1 at 0.5C, surpassing the cells used in the unmodified cellulose-based separator (87.7 mAh g −1 ) and GF (91.2 mAh g −1 ) separator, which validates the superiority of the modified separator and represents a simple and effective way for the development of advanced sodium-ion battery separators.