Significant effects of electron transport on the electrochemical properties of Ni2+- and Al3+-doped LiMn2O4

Abstract

The impedance spectra of undoped and Ni2- and Al 3-doped LiMn2O4 have been successfully modeled by an equivalent circuit. The results clearly evidence the coupling of the chemical diffusivity of Li ions evaluated from Warburg impedance and the electron transport in the cathode, which significantly influences the electrochemical properties of charge-transfer resistance and double layer capacitance. More importantly, the results not only provide insights into understanding their related physical fundamentals but also convey an important message that the performance of the lithium ion batteries can become optimal by manipulating the electron transport in cathode via the selection of proper additives. © 2011 The Electrochemical Society.