Influence of electrolyte constitution on metal dissolution and surface free energy correlation

Abstract

One of promising cathode for lithium ion battery is LiMn2O4 (LMO) due to its low cost and environmental inertness. However, LMO suffers from Mn dissolution followed by cell degradation. Mn-dissolution is heavily affected by electrode surface and electrolyte, so it is electrode/electrolyte interfacial phenomenon. However, more methodical research about the relationship between the electrolyte property and Mn-dissolution has not been carried out so far. This study examine the dependence of the Mn-dissolution on electrolyte constitution at various temperature and its kinetics. The Mn2+ ion concentration in the electrolyte at vari-ous temperature storage was analyzed by using atomic absorption spectroscopy (AAS). It was revealed that increasing EC content, storage duration and elevated temperature acceler-ates Mn-dissolution. It is diffusion controlled through the product layer. When increasing EC content, it diminish the activation energy of dissolution on electrode/electrolyte interface. ⓒ 2015 DGIST