Journal of Power Sources, Vol.268, 7-13, 2014
Al-Ga coating mechanism and discharge-charge characteristics of Li-Mn-O cathode powders at-30-55 degrees C
In the present study, LiMn2O4 cathode powders were coated with aluminum and gallium using a solution method with two-stage surface modification to obtain a Mn-based powder with an Al-Ga surface modification layer (MAG). It was found that the MAG powders have a higher capacity and excellent cycle characteristics at 55 degrees C at various current rates, and that the Al-Ga coating layer inhibits the precipitation of Mn ions, which increases the stability of the structure. In addition, although low temperatures generally lead to a reduction of conductivity and capacitance, the Al-Ga coating layer gives the MAG powders low-temperature resistance, with charge-discharge characteristics better at -30 degrees C. The Al-Ga surface modification coating layer of LiMn2O4 powder is the LiMn2-x-yAlxGayO4 phase, which reduces the negative impact of temperature variation. As a result, the MAG powders can be used for high C-rate charging discharging. (C) 2014 Elsevier B.V. All rights reserved.