Effect of Separator and Anode on Electrochemical Characteristics and Crystal Structure of Lithium-ion Battery Cathode Material 0.4Li2MnO3-0.6LiMn1/3Ni1/3Co1/3O2

Abstract

We studied the average crystal structural change during charging and discharging of a 0.4Li2MnO3-0.6LiMn1/3Ni1/3Co1/3O2 battery cathode in combination with a Li-metal anode, graphite anodes, and three types of separators. Prelithiation of the graphite anode enabled stable charge and discharge of the cathode. The average structure of the cathode after the 5th discharge did not change significantly due to the difference in the anodes and separators. However, after the 55th discharge, the difference in the electron density distribution and the distortion of the M-O6 octahedra for the different separators increased. The findings suggest that the changes in the crystal structure of a cathode over a long-term cycle should be studied with the anodes and separators used in actual batteries rather than Li-metal anodes and conventional separators.

Keywords

• lithium ion battery
• prelithiation
• separator
• crystal structure