微米尺寸二硫化钼层间化合物的电化学制备及其储镁性能

采用一种简便的电化学方法制备了有机阳离子(1-丁基-3-甲基咪唑阳离子,BMIM~+)插层的微米尺寸MoS_2层间化合物,并将其用作镁离子电池正极材料。所制备的MoS_2层间化合物(MoS_2-BMIM~+)具有扩大的层间距(0.98 nm),能有效降低Mg~(2+)的嵌入/脱出势垒,为存储Mg~(2+)提供了更多的活性位点,从而表现出显著提高的充电比容量和良好的倍率性能。MoS_2-BMIM~+在20 mA·g~(-1)电流密度下的充电比容量可达101.93 mAh·g~(-1)(约4倍于初始体相MoS_2)。我们进一步证明了这一方法同样适用于插层1-丁基-1-甲基吡咯烷双阳离子(Pyr~+_(14)),所得化合物的层间距为1.04 nm。

Electrochemical Preparation of MoS2 Intercalated Compound with Micron Size for Magnesium-Ion Storage

The micro-sized MoS₂ intercalated compound with the intercalant of 1-butyl-3-methyl-imidazolium cation (BMIM⁺) was prepared by a simple electrochemical method and used as cathode material of magnesium ion batteries. The MoS₂ intercalated compound (denoted as MoS₂-BMIM⁺) has an expanded interlayer spacing of 0.98 nm, which effectively reduced the insertion/extraction barrier of Mg²⁺ and provided abundant active sites for Mg²⁺ intercalation. Therefore, the MoS₂-BMIM+ deliverd a significantly improved charging capacity (101.93 mAh·g^-1 at 20 mA· g^-1, about 4 times as much as bulk MoS₂) and a good rate performance. We further show that this method can also be applied for the intercalation of 1-butyl-1-methylpyrrolidinium cation (Pyr₁₄⁺), which showed an interlayer spacing of 1.04 nm.