LiMn2O4@Au Particles as Cathodes for Li-Ion Batteries

LiMn2O4 (LMO) particles were coated with a Au shell by a simple and scalable electroless deposition for use as Li-ion battery cathodes. The Au shell was intended to limit the capacity fade commonly seen with LMO cathodes. Characterization by SEM, TEM, EELS, and AFM showed that the Au shell was approximately 3 nm thick. The Au shell prevented much of the Mn from dissolving in the electrolyte with 82% and 88% less dissolved Mn in the electrolyte at room temperature and 65 degrees C, respectively, as compared to the uncoated LMO. Electrochemical performance studies with half cells showed that the Au shell maintained a higher discharge capacity over 400 cycles by nearly 30% with 110 mA hr g(-1) for the 400th cycle as compared to a commercial LMO at 85 mA hr g(-1). Similarly, the capacity fade was reduced in full cells, where the coated LMO had 47% greater capacity after 400 cycles over the control. (C) 2014 The Electrochemical Society. All rights reserved.