In‐Situ Impedance Spectroscopy of LiMn _1.5 Ni _0.4 Cr _0.1 O ₄ Cathode Material

Abstract

LiMn1.5Nio.4Cro.1O4 cathode material has been synthesized using sol-gel method for possible application in high energy density Li ion rechargeable batteries. The half cells were tested using cyclic voltammetry and charge discharge cycling. Doping with 5% Cr seems to improve operating voltage (4.88V) and cell stability compared to un-doped material (4.7V). In-situ electrochemical impedance spectroscopic measurements were performed before and after each charge and discharge cycle, respectively. After several cycles the diffusional impedance for lithium at the cathode electrolyte interface was found to be high compared to the electron transfer impedance that followed a slight decrease in discharge capacity.