Graphene-like g-C3N4 nanosheets/sulfur as cathode for lithium-sulfur battery

Recently, various sulfur anchoring materials have been implied to improve the performance of lithium sulfur (Li-S) battery. Herein, we introduced graphene-like g-C3N4 nanosheets (GCN), a sheet-like material with high nitrogen (N) content of 56 wt % and high specific surface area of 209.8 m(2) g(-1), as a host to anchor lithium polysulfides. The composite with 70.4 wt % sulfur loading exhibited an initial reversible capacity of 1250 mA h g(-1) at 0.05C and a discharge capacity of 578.0 mA h g(-1) at 0.5C over 750 cycles. The excellent electrochemical performances can be attributed to the abundant N atoms in the GCN, which have the ability to anchor lithium polysulfides. Meanwhile, the high surface area of the GCN prevent sulfur, Li2S2 and Li2S from agglomerating. The result demonstrates that the GCN with abundant N atoms and high specific surface area could improve the electrochemical performance of Li-S battery effectively. (C) 2016 Elsevier Ltd. All rights reserved.