Adverse Effect of Ag Treatment on the Electrochemical Performance of the 5 V Nanometric Spinel LiNi[sub 0.5]Mn[sub 1.5]O[sub 4] in Lithium Cells

Abstract

The effect of coating the nanometric spinel with Ag on its rate capability was studied. The X-ray photoelectron spectroscopy (XPS) concentration depth profiles obtained reveal that the intensity of the Ag 3d peak remains unchanged for a long sputtering time, so the spinel particles do not seem to be coated by an Ag layer. The effect is detrimental at high charge/discharge rates and the addition of silver significantly degrades the rate capability of the spinel. Ag oxide nanoclusters formed in the first charge process possibly establish a barrier that hinders transfer of the high ion flux between the electrolyte and electrode.