Electrochemical and structural investigations of different polymorphs of TiO2 in magnesium and hybrid lithium/magnesium batteries. (1st July 2018)

• Record Type: Journal Article
• Authors: Fu, Qiang; Azmi, Raheleh; Sarapulova, Angelina; Mikhailova, Daria; Dsoke, Sonia; Missiul, Aleksandr; Trouillet, Vanessa; Knapp, Michael; Bramnik, Natalia; Ehrenberg, Helmut
• Is Part Of: Electrochimica acta. Volume 277(2018)
• Page Start: 20
• Page End: 29
• Publication Date: 2018-07-01
• Subjects: TiO2 -- Hybrid lithium/magnesium batteries -- In situ synchrotron -- X-ray photoelectron spectroscopy (XPS) -- Electrochemical performance; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.04.200
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Commercial nanocrystalline TiO2 anatase and self-prepared TiO2 (B) bronze synthesized by hydrothermal method were used as the cathode materials for Mg-ion and hybrid Li/Mg-ion batteries. The TiO2 anatase delivers high initial discharge/charge capacities of 225 mAh g −1 /204 mAhg −1 in a mixture of Phenylmagnesium chloride-AlCl3 /LiCl in tetrahydrofuran (APC/LiCl) hybrid electrolyte, while the TiO2 (B) shows high initial discharge/charge capacities of 260 mAh g −1 /231 mAh g −1 in the same hybrid electrolyte. Low discharge capacities of 67 and 57 mAh g −1 and strong polarization are observed for both TiO2 anatase and TiO2 (B) samples in pure APC electrolyte, respectively. In situ synchrotron diffraction strongly identifies that in APC/LiCl hybrid electrolyte, the TiO2 anatase undergoes structural evolution via a solid solution and a two-phase reaction mechanism, while TiO2 (B) exhibits a solid solution reaction during the discharge-charge processes. The analysis of X-ray photoelectron spectra for the TiO2 anatase and TiO2 (B) cathodes in the discharged/charged states reveals a change of Mg/Ti as well as Li/Ti ratios at different stages, which may indicate a contribution of both Mg and Li to the charge storage mechanism in the hybrid electrolyte. Graphical abstract: In APC/LiCl hybrid electrolyte, TiO2 anatase undergoes a phase transition mechanism, while TiO2 (B) exhibits a solid solution reaction. Image 1