Studies of a solid electrolyte interface coated with Li2CO3 on the carbon electrode in Li-ion batteries

Carbon material was prepared as a negative electrode to study the nature of the irreversible capacities in Li-ion battery. Typically, irreversible capacities of carbon anodes results from solvent decomposition reactions at the carbon surface and the irreversible insertion of lithium into the carbon layers. Solvent decomposition leads to a solid electrolyte interface (SEI) layer, an important factor related to internal cell resistance. To suppress the decomposition of electrolyte, an artificial SEI layer was formed on the carbon surface using Li2CO3 prior to the electrochemical experiments. The Li2CO3-coated carbon anode showed a decreased level of solvent decomposition. Chronopotentiometry, cyclic voltammetry, impedance spectroscopy, scanning electron microscopy, energy dispersive analysis of X-ray, and X-ray diffraction spectroscopy were used in an investigation of this effect.