Flexible ceramic based ‘paper separator’ with enhanced safety for high performance lithium-ion batteries: Probing the effect of ceramics impregnation on electrochemical performances

Cellulose is now considered as an appealing environment friendly material for the development of sustainable separators for rechargeable batteries. This study thus aims to develop high performance paper based ceramic separators with superior electrolyte wettability (>170 %), high thermal stability (>200 °C) and excellent flame safety. While developing paper based ceramic separator, extensive studies are carried out to understand thenature and functionality of different nano-structured ceramic materials (Al2O3, BaTiO3 and ZrO2) impregnated in paper matrix. Nano-ZrO2 facilitates an effective pathway for Li +-ion transport (tLi+ = 0.51), whereas BaTiO3 and Al2O3 ceramics show moderate Li +-ion transport properties (tLi+ of 0.29 and 0.30 respectively). Electrochemical Impedance Spectroscopy (EIS) measurement clearly reveals that ZrO2 exhibits more interfacial compatibility with the electrodes (MCMB and LiNi1/3Mn1/3Co1/3O2) compared to the other two ceramic separators during full cell operation. The developed paper separators show excellent electrochemical properties in terms of cycling (tested 300 cycles), multi-electrode compatibility and rate capabilities at different current densities of 0.1–1.2 mAcm−2. The pre- and post-electrochemical EIS data reveal that ZrO2 based impregnation offers significantly lower charge transfer resistance compared to the other two separators. The study thus demonstrates a real promise for its successful application in Li-ion battery towards achieving sustainability and safety.