Preparation and characterization of gold-codeposited LiMn₂O₄ electrodes

Additive-free, gold-codeposited LiMn₂O₄ electrodes are prepared by embedding LiMn₂O₄ particles in an electrodeposited coating of metallic gold on platinum-coated quartz crystals for microgravimetric evaluation with an electrochemical quartz crystal microbalance. The chemical and structural characteristics of the electrodes are studied by Raman spectroscopy and X-ray diffraction and the electrochemical properties by cyclic voltammetry. Test cells are assembled with the gold-codeposited electrode as the working electrode, lithium foil as the counter electrode and a reference electrode. A 1.0 M lithium perchlorate (LiClO₄), propylene carbonate (PC) solution is used as the electrolyte. Gold-codeposited LiMn₂O₄ electrodes prepared at deposition times of 4-8 min have a good adhesion of powder to the substrate. The cyclic voltammograms show little difference in the exchanged charge with cycling. Scanning electron microscopy shows fracture of the LiMn₂O₄ powders induced by a dimensional mismatch in the particles after cyclic voltammetric tests at high scan rates.