Hollow spherical Lanthanum oxide coated separator for high electrochemical performance lithium-sulfur batteries

Highlights: • Hollow spherical La₂O₃ was fabricated by a spray dryer. • Hollow spherical La₂O₃ was coated on the routine separator and equipped in Li-S battery. • La₂O₃ coated layer can effectively trap lithium polysulfides and accelerate the electrochemical kinetics of the redox reactions. - Abstract: In order to alleviate the shuttle effects of lithium polysulfides (LiPSs) in Lithium sulfur batteries. Lanthanum oxide (La₂O₃) with a hollow spherical structure was synthesized by a spray dryer and coated on the routine separator evenly as the main coating material to trap LiPSs and accelerate the electrochemical kinetics of the redox reactions.CV tests and EIS analysis demonstrate that Li-S battery equipped with this modified separator shows higher discharge potential and faster electrochemical reaction in comparison with the routine separator and super P coated separator samples. Charge/discharge measurements at different current densities show that Li-S cell with the hollow spherical La₂O₃ coated separator can deliver an initial capacity of 966 mA hg⁻¹ at 1C and maintains a discharge capacity of 720 mA hg⁻¹ after 200 cycles. Besides, it presents a high discharge capacity of 820 mA hg⁻¹ at 2C which demonstrates a promising rate performance.