State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering , Wuhan University of Technology , Luoshi Road 122 , Wuhan , 430070 Hubei , China.
ACS Appl Mater Interfaces. 2018 Oct 31;10(43):36988-36995. doi: 10.1021/acsami.8b12662. Epub 2018 Oct 18.
As a novel and potential transition metal dichalcogenide (TMDC), NbSe has low ion diffusion barrier when applied in energy-storage systems, such as traditional lithium-ion batteries and novel magnesium-ion batteries (MIBs). In this work, we have developed a novel hexagonal NbSe material with a nanosized surface via a facile microwave-hydrothermal method. The Li-storage mechanism of NbSe with surface conversion and internal intercalation is thoroughly revealed by in situ X-ray diffraction (XRD), ex situ high-resolution transmission electron microscopy, and ex situ scanning electron microscopy. Besides, Mg intercalation mechanism is confirmed via ex situ XRD and ex situ X-ray photoelectron spectroscopy for the first time. In addition, as the cathode for MIBs, NbSe with a nanosized surface exhibits a high rate capacity of 101 mA h g at 200 mA g with a high discharge plateau at 1.30 V. Our work builds a deep understanding of ion-storage mechanisms in TMDCs and provides guidance for designing new electrode materials with high electrochemical performances.
作为一种新型的潜在过渡金属二卤化物（TMDC），NbSe 在储能系统中具有较低的离子扩散势垒，例如传统的锂离子电池和新型的镁离子电池（MIB）。在这项工作中，我们通过简便的微波水热法开发了一种具有纳米表面的新型六方 NbSe 材料。通过原位 X 射线衍射（XRD）、非原位高分辨率透射电子显微镜和非原位扫描电子显微镜彻底揭示了 NbSe 的表面转化和内部插层的储锂机制。此外，首次通过非原位 XRD 和非原位 X 射线光电子能谱证实了 Mg 嵌入机制。此外，作为 MIB 的正极，具有纳米表面的 NbSe 在 200 mA g 的高电流密度下表现出 101 mA h g 的高倍率容量，在 1.30 V 时具有高放电平台。我们的工作深入了解了 TMDC 中的离子存储机制，并为设计具有高电化学性能的新型电极材料提供了指导。
