Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7736561 | Journal of Power Sources | 2014 | 10 Pages |
Abstract
The effect of Ti-substitution on the electrochemical properties of LiNi0.5Mn1.5âxTixO4 was investigated by using half-cells paired with lithium metal, and full-cells paired with either graphite or Li4Ti5O12 (LTO) negative electrodes. In half-cells, Ti-substitution increased the operation voltage, but reduced the specific capacity. While some improvements in performance, such as higher operation voltage and less self-discharge, could be measured in the half-cells, the critical advantages of the Ti-substitution were readily observed in full-cell cycling. Compared with Ti-free LiNi0.5Mn1.5O4, the LiNi0.5Mn1.5âxTixO4 electrodes delivered improved full-cell performance whether paired with graphite or LTO negative electrodes; greater cycle life, higher cell operating voltage, and lower voltage polarization on charging/discharging. Based on relatively low self-discharge and high Coulombic efficiency, it is suggested that the Ti-substitution in LiNi0.5Mn1.5âxTixO4 retards electrolyte oxidation. In addition, scanning electron microscopy (SEM) images revealed that cycle-aged LiNi0.5Mn1.2Ti0.3O4 particle surfaces remained relatively clean compared with those of LiNi0.5Mn1.5O4 particles. These results are consistent with the hypothesis that Ti-substitution reduces electrolyte oxidation and retards or prevents some of the degradative parasitic reactions at the electrode/electrolyte interfaces during battery cell operation.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Jung-Hyun Kim, Nicholas P.W. Pieczonka, Yang-Kook Sun, Bob R. Powell,