Wang Xuefeng, Li Yejing, Guan Zhaoruxin, Wang Zhaoxiang, Chen Liquan
Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing 100190 (P. R. China).
Chemistry. 2015 Apr 20;21(17):6465-8. doi: 10.1002/chem.201406635. Epub 2015 Mar 9.
Low storage capacity and poor cycling stability are the main drawbacks of the electrode materials for sodium-ion (Na-ion) batteries, due to the large radius of the Na ion. Here we show that micro-structured molybdenum disulfide (MoS2 ) can exhibit high storage capacity and excellent cycling and rate performances as an anode material for Na-ion batteries by controlling its intercalation depth and optimizing the binder. The former method is to preserve the layered structure of MoS2 , whereas the latter maintains the integrity of the electrode during cycling. A reversible capacity of 90 mAh g(-1) is obtained on a potential plateau feature when less than 0.5 Na per formula unit is intercalated into micro-MoS2 . The fully discharged electrode with sodium alginate (NaAlg) binder delivers a high reversible capacity of 420 mAh g(-1) . Both cells show excellent cycling performance. These findings indicate that metal chalcogenides, for example, MoS2 , can be promising Na-storage materials if their operation potential range and the binder can be appropriately optimized.
由于钠离子半径较大，存储容量低和循环稳定性差是钠离子电池电极材料的主要缺点。在此我们表明，通过控制其嵌入深度并优化粘结剂，微结构二硫化钼（MoS2）作为钠离子电池的负极材料可展现出高存储容量以及出色的循环和倍率性能。前一种方法是保留MoS2的层状结构，而后一种方法是在循环过程中保持电极的完整性。当每分子式单元中嵌入少于0.5个钠时，在微MoS2上的一个电位平台特征处可获得90 mAh g(-1)的可逆容量。使用海藻酸钠（NaAlg）粘结剂的完全放电电极具有420 mAh g(-1)的高可逆容量。两种电池均展现出出色的循环性能。这些发现表明，如果金属硫族化合物（例如MoS2）的工作电位范围和粘结剂能够得到适当优化，它们有望成为有前景的钠存储材料。
