Synthesis and characterization of Li[Li0.27Cr0.15Al0.05Mn0.53]O-2 cathode for lithium-ion batteries

The effect of doping aluminum in the Li[Li0.27Cr0.15Al0.05Mn0.53]O-2 layered cathode material has been investigated. The citric acid assisted sol-gel process was used to prepare the cathode material. The electrochemical properties of the cathode material were characterized in coin cells assembled in an argon-filled dry glove box. The Al-doped cathode delivered an initial discharge capacity of 198 mAh/g with a current density of 0.12 mA/cm(2). A slight change in the shape of the discharge curve was observed with the substitution of aluminum in Li1.27Cr0.2Mn0.53O2 cathode material. A decreased resistance was observed in the aluminum-doped cathode from the ac impedance spectroscopy. Regarding the state of existence of chromium and manganese ions in the transition metal layer, X-ray photoelectron spectroscopy study results indicated that Mn4+ was reduced to Mn3+ at the end of the discharge.