Mns@N/S-C Anode Electrode with High Lithium Storage Property By Simple Polyol Refluxing Method

Abstract

Transition-metal sulfides are of significant interest as rechargeable battery anodes owing to their low cost, wide availability, eco-friendliness, and high theoretical capacities. However, the structural change due to the volume change during the electrochemical reaction and the capacity decrease due to the dissolution of polysulfide remain as problems. Herein, a simple one-pot polyol refluxing method is used for fabricating a manganese sulfide (MnS) electrode composited with nitrogen and sulfur co-doped carbon (MnS@NS-C) for high-power lithium-ion batteries. This composite electrode is a carbon-coated nanostructure, exhibits unique spherical particle morphology with optimized average partical size (300 < x < 500nm) and porous features. Owing to its nanostructure, porous nature, and an electrically conducting carbon coating network co-doped with heteroatoms, the composite electrode overcomes the strong structural variations and polysulfide dissolution to afford high practical storage capacities, long-term cycle stability, and outstanding rate capability. The MnS@NS-C electrode demonstrated high reversible lithium storage capacities of 999 mAh g-1 at 0.1 A g-1, the highest reversible capacity of 761 mAh g-1 at 2 A g-1 for over 300 cycles, and average rate capacities of 453 mAh g-1 at 10 A g-1. In-situ X-ray diffraction investigations indicated a uniquely combined intercalation-cum-conversion reaction mechanism leading to β-Li2(1-x)MnS, Li2S, and Mn discharge products. The results of this study can provide deep insights into understanding reaction mechanism and motivate further study of transition-metal sulfides for prospective high-energy battery applications. References N. Nitta, F. Wu, J. T. Lee and G. Yushin, Mater. Today, 2015, 18, 252–264. V. Etacheri, R. Marom, R. Elazari, G. Salitra and D. Aurbach, Energy Environ. Sci., 2011, 4, 3243–3262. Y. Hao, C. Chen, X. Yang, G. Xiao, B. Zou, J. Yang and C. Wang, J. Power Sources, 2017, 338, 9–16. Y. Ye, C. Jo, I. Jeong and J. Lee, Nanoscale, 2013, 5, 4584–4605. L. Zhang, L. Zhou, H. Bin Wu, R. Xu and X. W. Lou, Angew. Chemie - Int. Ed., 2012, 51, 7267–7270.