Effect of Structural Integration on Electrochemical Properties of 0.5Li2MnO3-0.5Li(Mn0.375Ni0.375Co0.25)O2 Composite Cathodes for Lithium Rechargeable Batteries

In the present work, we have investigated the effect of the structural integration between Li2MnO3 and Li(Mn0.375Ni0.375Co0.25)02 components on the electrochemical properties of the resultant compounds. We have adopted three processing methodologies to attain the structural integration of Li2MnO3 component in Li(Mn(0.375)Ni(0.375)Co0 025)02 layered cathode. The best electrochemical properties are achieved in the composites where Li2MnO3 type nano-domains were formed in situ in Li(Mn(0.37)sNi(0.375)Co(0.25))02 particles. For these composites the 1st cycle discharge capacity (at 10 mAg(-1) rate) was measured to be 300 mAhg(-1) with a capacity retention 220 mAhg(-1) after 50 cycles. These cathodes exhibit decent rate capability with typical discharge capacity 120 mAhg(-1) at 300 mAg(-1) rate. One of the remarkable finding of the present work is to demonstrate that in order to yield attractive electrochemical performance of such integrated cathode; structural integration between the Li2MnO3 and Li(Mn-0.375 Ni-0.375 Co0,25)02 is essential. To achieve better structural integrity in the physically mixed composites, finer particle size of the individual (Li2MnO3 and Li(Mn0.375Ni0.375Co0.25)02) components, through intermixing between them, and optimization of calcinations temperature and time are recommended. (C) 2013 The Electrochemical Society.