Scalable 3D Honeycombed CoO Modified Separators as Polysulfides Barriers for High-Performance Li-S Batteries.

Lithium sulfur batteries (LSBs) are regarded as one of the most promising energy storage devices due to the high theoretical capacity and energy density. However, the shuttling lithium polysulfides (LiPSs) from the cathode and the growing lithium dendrites on the anode limit the practical application of LSBs. To overcome these challenges, a novel three-dimensional (3D) honeycombed architecture consisting of a local interconnected CoO successfully assembled into a scalable modified layer through mutual support, which is coated on commercial separators for high-performance LSBs. On the basis of the 3D honeycombed architecture, the modified separators not only suppress effectively the "shuttle effects" but also allow for fast lithium-ions transportation. Moreover, the theoretical calculations results exhibit that the collaboration of the exposed (111) and (220) crystal planes of CoO is able to effectively anchor LiPSs. As expected, LSBs with 3D honeycombed CoO modified separators present a reversible specific capacity with 1007 mAh g over 100 cycles at 0.1 C. More importantly, a high reversible capacity of 808 mAh g over 300 cycles even at 1 C is also acquired with the modified separators. Therefore, this proposed strategy of 3D honeycombed architecture CoO modified separators will give a new route to rationally devise durable and efficient LSBs.