Electrochemical kinetics and cycling performance of nano Li[Li0.23Co0.3Mn0.47]O2 cathode material for lithium ion batteries

Li[Li0.23CO0.3Mn0.47]O-2 cathode material was prepared by a sol-gel method. The material had a primary particle size of about 100 nm, covered by a 30 angstrom of Li2CO3 layer. The material showed promising electrochemical performance when cycled up to 3C rate. The electrochemical kinetics of the first charge was much slower than that of the second charge, due to the complex electrochemical process which involved not only Li+ diffusion but also release of oxygen. By taking account of this, the material was pre-charged very slowly (similar to C/50) in the first cycle. This led to excellent electrochemical performance in the following cycles. For instance, the 1 C-rate capacity increased to 168 mA h g(-1) after 50 cycles, comparing with the 145 mA h g(-1) obtained without pre-charging. (C) 2009 Elsevier B.V. All rights reserved.