N- and S-doped ordered mesoporous carbon tubes with efficient S confinement for high-performance Li-S batteries

The insulating properties of S/Li2S2/Li2S and the soluble Li2S4/Li2S6/Li2S8 obstruct the practical application of Li-S batteries. In this work, highly ordered N and S co-doped mesoporous carbon tubes (NSMCTBs) with high specific surface areas and large pore volume are employed to confine and improve the utilization efficiency of S species in Li-S batteries. The strong SnLi2 center dot center dot center dot N interaction and S-S chemical bond between thiophenic S and Li2Sn guarantee the exceptional electrochemical performance of as-prepared NSMCTBs/S cathode. A relatively high discharge capacity of 1315.2 mAh g(-1) is achieved for the first cycle at 0.5 C and maintained at 644.1 mAh g(-1) after 500 cycles. The NSMCTBs/S with high S content of up to 80%, it also delivers a discharge capacity of 1092.1 mAh g(-1) and considerable cycling performance. More importantly, the NSMCTBs/S can effectively suppress the self-discharge behavior of Li-S batteries. (C)& nbsp;2022 Elsevier Ltd. All rights reserved.