Improve electrochemical performance of CeO₂ surface modification LiNi_0.80Co_0.15Al_0.05O₂ cathode material

¹ Faculty of Chemistry & Chemical Engineering, Qujing Normal University, Qujing 655011, P.R. China
² Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, P.R. China

^a e-mail: zyj0904@yahoo.com

Received: 22 January 2014
Revised: 27 February 2014
Accepted: 10 March 2014
Published online: 12 June 2014

Abstract

Lithium ion battery cathode material LiNi_0.8Co_0.15Al_0.05O₂ cathode has successfully prepared by co-precipitation. CeO₂ surface modification has improved LiNi_0.80Co_0.15Al_0.05O₂ electrochemical performance use sol-gel method and subsequent heat treatment at 600 °C for 5 h. Different to other conventional coating material, CeO₂ coating layer can not only inhibit the reaction of the electrode and the electrolyte, but also can reduce the impedance of electron transfer due to its high conductivity, and inhibit the production of Ni²⁺ because of its high oxidation. The surface-modified and pristine LiNi_0.80Co_0.15Al_0.05O₂ powders are characterized by XRD, SEM, TEM, XPS, CV and DSC. When CeO₂ coating is 0.02% (mole ratio), contrast to pristine NCA, the CeO₂-coated NCA cathode exhibits no decrease in its initial specific capacity of 184 mAh g ⁻¹ (at 0.2 C) and excellent capacity retention (86% of its initial capacity at 1 C) between 2.75 and 4.3 V after 100 cycles. The results indicate that the CeO₂ surface treatment should be an effective way to improve cycle properties due to CeO₂ inhibit the electrodes and the electrolyte side effects.