Reconfiguration of lithium sulphur batteries: Enhancement of Li-S cell performance by employing a highly porous conductive separator coating

Li-S batteries are an emerging technology and the most promising successor of current lithium ion technology. While there is great perspective in terms of superior theoretical specific capacity and energy density great challenges have to be addressed. One major challenge, severely limiting cycle performance and capacity retention, is the shuttling of polysulphide species. In this contribution we show a reconfiguration of the usual Li-S cell. Instead of generating a carbon/sulphur composite by melt infiltration a highly porous, conductive nitrogen-rich carbon material (TNC) is coated onto a commercial polypropylene separator foil. The thin conductive coating of TNC on the separator enables the application of very simple sulphur/carbon black cathodes. Because the melt infiltration of sulphur in a porous host material becomes unnecessary the electrode processing is significantly simplified. The specific capacity and cycling stability of reconfigurated cells are both improved significantly compared to the performance of a standard cell setup using a pristine separator. At a constant charging rate of C/5 cells with modified separator showed 2.5 times higher residual capacity (1016 mAh g(-1)) than cells with pristine separator (405 mAh g(-1)). (C) 2015 Elsevier B.V. All rights reserved.