Effect of Mg and Al Dual Doping on High Voltage Cycling of LiNi0.4Mn0.4Co0.2O2 Lithium-ion Battery Cathode Material

Abstract

Nano-sized LiNi0.4Mn0.4Co0.2O2 lithium-ion battery cathode materialswith and without dual Mg & Al doping were synthesized by Pechini method. Thepowdered materials were characterized using X-ray diffraction, scanning electronmicroscopy and electrochemical techniques. X-ray analyses showed that 003/104peaks intensity ratio increased from 0.95 for undoped material to 1.27 for dopedmaterial, thereby suggesting that dual doping was beneficial in terms reducingLi/Ni cation mixing. Although dual doping caused some reduction in initialdischarge capacity (140 vs. 128 mAh/g) and increase in charge transfer resistancerelative to the undoped material, it noticeably helped increase capacity retentionduring battery testing at high voltage.