Huang Lei, Wei Qiulong, Xu Xiaoming, Shi Changwei, Liu Xue, Zhou Liang, Mai Liqiang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China.
Phys Chem Chem Phys. 2017 May 31;19(21):13696-13702. doi: 10.1039/c7cp00990a.
Sodium ion batteries (SIBs) possess the potential to realize low-cost and large-scale energy storage due to the abundance of sodium. However, the large ionic radius of sodium often leads to sluggish kinetics and large volume change, limiting the further development of SIBs. Layered MoS, with a large interlayer distance, is a promising intercalation anode material for SIBs. In this work, we report the synthesis of methyl-functionalized MoS (M-MoS) nanosheets through a facile second solvothermal method. During the second solvothermal treatment, the pristine MoS is mostly converted from the 2H to 1T phase and the interlayer distance is expanded from 0.65 to 0.80 nm. When evaluated as the anode for SIBs, the M-MoS exhibits superior cycling stability and rate capability. Kinetic analysis shows that the capacity is mainly contributed from a pseudocapacitive process. Ex situ XRD shows that the M-MoS exhibits inhibited lattice breathing and thus reduced volume change during cycling. This work demonstrates that the M-MoS is a promising candidate for pseudocapacitive sodium storage.
钠离子电池（SIBs）由于钠资源丰富而具有实现低成本大规模储能的潜力。然而，钠的离子半径较大，常常导致动力学迟缓以及体积变化大，这限制了钠离子电池的进一步发展。具有较大层间距的层状二硫化钼是一种很有前景的用于钠离子电池的插层阳极材料。在这项工作中，我们报道了通过一种简便的二次溶剂热法合成甲基官能化二硫化钼（M-MoS）纳米片。在二次溶剂热处理过程中，原始的二硫化钼大多从2H相转变为1T相，层间距从0.65纳米扩大到0.80纳米。当作为钠离子电池的阳极进行评估时，M-MoS表现出优异的循环稳定性和倍率性能。动力学分析表明，容量主要来自赝电容过程。非原位XRD表明，M-MoS在循环过程中晶格呼吸受到抑制，从而体积变化减小。这项工作表明，M-MoS是一种很有前景的赝电容钠存储候选材料。
