A high-powered concentration-gradient Li(Ni0.85Co0.12Mn0.03)O2 cathode material for lithium ion batteries

A high-powered concentration-gradient cathode material with an average composition of Li(Ni0.85Co0.12Mn0.03)O-2 has been successfully synthesized by a co-precipitation method. The Li(Ni0.85Co0.12Mn0.03)O-2 has a core of Li(Ni0.9Co0.1)O-2 that is rich in Ni and a concentration-gradient shell having decreased Ni content and increased Mn content. The electrochemical properties of the concentrationgradient material are studied and compared to those of the core Li(Ni0.9Co0.1)O-2 material alone. In the concentration-gradient material of Li(Ni0.85Co0.12Mn0.03)O-2 , the Ni-rich core delivers a very high capacity, while the Mn-rich concentration-gradient shell improves the cycling stability and rate performance. The electrochemical properties of this cathode material are found to be far superior than those of the core Li(Ni0.9Co0.1)O-2 material. At room temperature, the initial capacity of the concentration-gradient Li(Ni0.85Co0.12Mn0.03)O-2 is 195 mAh g(-1) at 1C between 2.8 and 4.3 V and retains 95.5% after 100 cycles. Moreover, the composite has a good rate performance with a high capacity of about 190 mAh g(-1)even at 2C rate. (C) 2014 Elsevier B.V. All rights reserved.