@article{Yang2017, 
author = {Wanfeng Yang and Jiawei Wang and Conghui Si and Zhangquan Peng and Zhonghua Zhang},
title = {Tungsten diselenide nanoplates as advanced lithium/sodium ion electrode materials with different storage mechanisms},
year = {2017},
journal = {Nano Research},
volume = {10},
number = {8},
pages = {2584-2598},
keywords = {X-ray diffraction, lithium/sodium ion battery anodes, WSe2 nanoplates, lithium/sodium storage mechanisms},
url = {https://www.sciopen.com/article/10.1007/s12274-017-1460-3},
doi = {10.1007/s12274-017-1460-3},
abstract = {Transition-metal dichalcogenides (TMDs) exhibit immense potential as lithium/ sodium-ion electrode materials owing to their sandwich-like layered structures. To optimize their lithium/sodium-storage performance, two issues should be addressed: fundamentally understanding the chemical reaction occurring in TMD electrodes and developing novel TMDs. In this study, WSe2 hexagonal nanoplates were synthesized as lithium/sodium-ion battery (LIB/SIB) electrode materials. For LIBs, the WSe2-nanoplate electrodes achieved a stable reversible capacity and a high rate capability, as well as an ultralong cycle life of up to 1,500 cycles at 1,000 mA·g–1. Most importantly, in situ Raman spectroscopy, ex situ X-ray diffraction (XRD), transmission electron microscopy, and electrochemical impedance spectroscopy measurements performed during the discharge–charge process clearly verified the reversible conversion mechanism, which can be summarized as follows: WSe2 + 4Li+ + 4e– ↔ W + 2Li2Se. The WSe2 nanoplates also exhibited excellent cycling performance and a high rate capability as SIB electrodes. Ex situ XRD and Raman spectroscopy results demonstrate that WSe2 reacted with Na+ more easily and thoroughly than with Li+ and converted to Na2Se and tungsten in the 1st sodiated state. The subsequent charging reaction can be expressed as Na2Se → Se + 2Na+ + 2e–, which differs from the traditional conversion mechanism for LIBs. To our knowledge, this is the first systematic exploration of the lithium/sodium-storage performance of WSe2 and the mechanism involved.}
}