The Electrochemical Stability of Spinel Electrodes Coated with ZrO[sub 2], Al[sub 2]O[sub 3], and SiO[sub 2] from Colloidal Suspensions

Stoichiometric LiMn2O4 and substituted Li 1.05M0.05Mn1.9O4 (M = Al,Ni) spinel electrodes, coated with ZrO2, Al2O3, and SiO2 from colloidal suspensions, have been evaluated in lithium cells. ZrO2-coated Li1.05Ni0.05Mn 1.9O4 electrodes provide the best cycling stability at 50°C. The excellent cycling stability is attributed to a porous network of amphoteric ZrO2 particles, less than 4 nm in dimension, that protect the spinel surface from acid attack by scavenging HF and H2O from the electrolyte, while still allowing access of the electrolyte to the active electrode.