A method of stabilizing a metal oxide or lithium-metal-oxide electrode comprises contacting a surface of the electrode, prior to cell assembly, with an aqueous or a non-aqueous acid solution having a pH greater than 4 but less than 7 and containing a stabilizing salt, for a time and at a temperature sufficient to etch the surface of the electrode and introduce stabilizing anions and cations from the salt into said surface. The structure of the bulk of the electrode remains unchanged during the acid treatment. The stabilizing salt comprises fluoride and at least one cationic material selected from the group consisting of ammonium, phosphorus, titanium, silicon, zirconium, aluminum, and boron.