Surface modification of LiSr0.002Ni0.9Co0.1O2 by overcoating with a magnesium oxide

Commercially obtained LiSr0.002Ni0.9Co0.1O2 was modified by overcoating its surface with MgO. As the surface was modified, onset temperature of therma l dissociation was increased about 10 degrees C, and heat dissipation durin g thermal decomposition was diminished to a substantial extent. Lithium-ion batteries whose cathodes were made from the surface-modified LiSr0.002Ni0. 9Co0.1O2 exhibited improved performance, especially at the demanding rate o f 1 C. Tendency toward explosion in the cylindrical battery was largely all eviated by the surface treatment, even though thr safety rating has not yet reached the industrial criterion. (C) 2000 The Electrochemical Society. S1 099-0062(99)07-054-6. All rights reserved.