In situ Raman spectroscopy of insertion electrodes for lithium-ion batteries and supercapacitors: First cycle effects

详细信息	查看全文 | 推荐本文 |

• 作者：Laurence J. Hardwick ; Patrick W. Ruch ; Matthias Hahn ; Werner Scheifele ; R&#xfc ; diger Kö ; tz ; Petr Nová ; k
• 关键词：A. Electronic ; A. Interfaces ; C. Raman spectroscopy ; D. Electrochemical properties ; D. Defects
• 刊名：Journal of Physics and Chemistry of Solids
• 出版年：2008
• 期刊代码：69_00223697
• 类别：ch
• 出版时间：May-June 2008
• 卷：69
• 期：5-6
• 页码：1232-1237
• 文件大小：397 K

摘要

In situ Raman spectroscopy was used to demonstrate ion intercalation into microcrystalline graphite (KS44) during cyclic voltammetry experiments from the ionic liquid 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)-imide (EMI-TFSI). This was seen by a split of the G-band (1578 cm⁻¹) into the E_2g2(i) band at 1578 cm⁻¹ and E_2g2(b) band at 1600 cm⁻¹, which occurred below +1.0 V for EMI⁺ and above +4.65 V vs. Li/Li⁺ for TFSI⁻. Moreover, ion intercalation was seen to cause irreversible structural changes to the graphitic lattice. The Raman spectrum of activated carbon (Picactif) exhibits broad G- and D-bands around 1587 and 1315 cm⁻¹, respectively. Changes were observed during potential cycling in 1 mol dm⁻³ tetraethylammonium-tetrafluoroborate (TEABF₄) in acetonitrile that concerned only changes in Raman intensity and shifts in wavenumber of both D- and G-bands. It is hypothesised that the D-band could be composed of two contributions reflecting the D-band of crystalline domains and of cross-linkers. After ion insertion, the contribution from stacked sheets maybe lost, resulting in a wavenumber shift of the band.