Coating of spinel LiNi0.5Mn1.5O4 cathodes with SnO2 by an electron cyclotron resonance metal–organic chemical vapor deposition method for high-voltage applications in lithium ion batteries.

Tin oxide coating by employing electron cyclotron resonance metal–organic chemical vapor deposition was performed on 5 V-class spinel LiNi 0.5 Mn 1.5 O 4 cathode electrodes prepared by a conventional tape-casting method. The pristine and SnO 2 -deposited LiNi 0.5 Mn 1.5 O 4 electrodes were characterized by X-ray diffraction, field-emission electron probe microanalyzer, field-emission scanning electron microscopy, Auger electron spectroscopy, charge–discharge measurements, and electrochemical impedance spectroscopy were evaluated in lithium cells using the fabricated electrodes. The SnO 2 -deposited LiNi 0.5 Mn 1.5 O 4 electrodes exhibited better rate capability at room temperature and superior electrochemical performance during the storage test evaluated at 60 °C in a fully charged state than the pristine LiNi 0.5 Mn 1.5 O 4 electrode. Also, surface modification of the LiNi 0.5 Mn 1.5 O 4 electrode was found by impedance analyses to be effective for suppressing the increase of the charge transfer resistance during the storage test at elevated temperatures. [ABSTRACT FROM AUTHOR]