טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentShasha Hila
SubjectCathode Materials for Secondary Magnesium Batteries
DepartmentDepartment of Materials Science and Engineering
Supervisor Professor Yair Ein-Eli
Full Thesis textFull thesis text - English Version


Abstract

Secondary magnesium batteries, based on a reversible intercalation of Mg ion into a solid host, are a promising alternative to Li-ion batteries, which have almost reached their theoretical capacity. Mg-based battery is attractive as Mg anode is inexpensive, safe and has low equivalent weight.

In this research, pure spinel intercalation MgzNiMn2-zO4 (0 < z ≤ 1) compounds were synthesized and studied as a cathode material for rechargeable Mg battery. The Mg-based spinel oxides are promising candidates owing to cross-linked channels in their three-dimensional lattice structure, allowing a fast cation insertion and extraction. The materials were characterized using X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS), high resolution scanning electron microscopy (HRSEM) and energy dispersive spectroscopy (EDS).

The viability of the spinel phase as a reversible intercalation Mg ion host was investigated using Mg metal as a negative electrode and organometallic electrolyte solution (DCC). In order to use high voltage Mg insertion material and to tackle the challenges of corrosion and irreversible metallic magnesium deposition, Mg-ion cells comprised of MgNiMn2O4 spinel cathode, Mo6S8 chevrel anode and AN or ionic liquid electrolytes were studied.

CVs of the spinel electrode and DCC, 0.25 M Mg(TFSI)2/AN or 0.25M Mg(TFSI)2/BMPTFSI did not show indications of Mg2 extraction at room temperature. Elevating the temperature (80 °C) resulted in decomposition of the MgNiMnO4 cathode.