Enhancing the electrochemical performances of Li2S-based cathode through conductive interface design and addition of mixed conductive materials

The significantly-high theoretical energy density and eco-sustainability of lithium sulfur batteries (LSBs) arouses a rapid surge of interest in recent years. However, some key issues of cathode, for instance, the polysulfides confinement, low ion/electrons transfer and etc., hinder the practical utilization of LSBs. Herein, such issues could be carefully handled by using the conductive polypyrrole as polysulfides wrap-per. The polypyrrole with pyrrole rings can efficiently confine polysulfides inside cathode for redox. Meanwhile, the conductive polypyrrole with delocalized pi-electron cloud can facilitate electrons transfer. Besides, the addition of carbon nanotube (CNT) and oxidized graphene (GO) can enhance the conductiv-ity of cathode material. As a result, the Li2S/CNT/GO/PPy cathode delivers a cycling capacity of 525 mAh g(-1) with a low-capacity decay rate of 0.065 % cycle(-1) after 400 cycles. Therefore, the lithium-sulfur bat-tery with Li2S-based and PPy-wrapped cathode could reasonably be counted as a potential alternative of long-cycling Li-ion cells. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The use of polypyrrole as a polysulfides wrap-per, combined with carbon nanotube and oxidized graphene, can enhance the conductivity of cathode material in lithium sulfur batteries. This leads to improved cycling capacity and cycling performance, making it a potential alternative for long-cycling lithium-ion cells.