Influence of fuels in the sol-gel combustion synthesis of Li2MnO3 positive electrode material for Li-ion battery

Abstract

The capacities of Li2MnO3 depend on the method of synthesis and synthesis conditions. The influence of the nature of fuel and fuel compositions on the sol-gel combustion synthesis (SCS) of Li2MnO3 and the concomitant effect on their electrochemical performance are reported. The use of glycine, citric acid fuels and their mixtures in the fuel stoichiometric compositions resulted in a violent reaction leading to loss of powders. Therefore, the fuel-rich (FR) composition that allows for better complexation of the metals in solution and doesn't result in any violent reaction is recommended in the SCS of Li2MnO3 and other ceramic oxides. The glycine FR composition produced Li2MnO3 with the poorest electrochemical performance that was ascribed to its rough morphology. The citric acid FR Li2MnO3 sample (C-FR) delivered the most comprehensive electrochemical performance considering its increasing discharge capacities with an increase in the current density, its suppression of the charge transfer resistance after the rate capability test, and good rate performance. The improved electrochemical performances of C-FR were attributed mainly to its large particle size and well-developed crystallites. The results show that the SCS of C-FR Li2MnO3 sample could be further optimized to exploit better electrochemical properties of this material.