Authors: Jie Shu Miao Shui Dan Xu Shan Gao Tingfeng Yi DongJie Wang Xing Li Yuanlong Ren
Publish Date: 2011/04/06
Volume: 17, Issue: 6, Pages: 503-509
Abstract
In this paper ex situ and in situ devices for Raman observations are designed and compared with each other by using lithium titanate as working electrode In situ cell is made for Raman spectroscopy based on a confocal microscope Raman spectrometer The instant evolutions of lithium titanate anode material during cycle can be recorded by in situ Raman in detail Although the in situ technique is an important method to monitor the structure evolution of lithium titanate it is difficult to conduct an in situ experiment in most laboratories Moreover the existence of electrolyte and surface deposits weakens the Raman signals of sample Therefore the structure evolution of Li4Ti5O12 cannot be described accurately For comparison airfree ex situ device is a simple and cheap tool to achieve the information from lithiated and delithiated samples By removing the electrolyte and deposits on the sample with dimethyl carbonate the ex situ Raman pattern shows higher signal to noise ratio than that of in situ Raman result As a result the shift and recovery of ex situ Raman bands confirms that the electrochemical reaction of Li4Ti5O12 with Li in 00–20 V is not a fully reversible process but a partially reversible processThis work is supported by National Science Foundation of China No 50902001 and Key Project of Chinese Ministry of Education No 210083 This is also sponsored by Academic Discipline Program No xkl068 School Research Fund No XYL10009 Hulan Excellent Doctoral Fund and K C Wong Magna Fund in Ningbo University A project supported by Scientific Research Fund of Zhejiang Provincial Education Department No Y200907481 and programs supported by Ningbo Natural Science Foundation No 2010A610145 are appreciated
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