Investigations on Electrochemical Behavior and Structural Stability of Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ Lithium-Ion Cathodes via in-Situ and ex-Situ Raman Spectroscopy

Abstract

In the present work, we performed electrochemical measurements to investigate Li (de)intercalation behavior and Raman spectroscopic studies to understand structural changes during charge–discharge processes and verify the structural stability after electrochemical cycling of the AlPO4-coated Li1.2Mn0.54Ni0.13Co0.13O2 composite cathode. Physicochemical characterization techniques confirmed the well-crystalline layered composite nature of the prepared material. Electrochemical measurements indicated high discharge capacities of ∼230 and 160 mAh/g at C/20 and 1C, respectively, with good cycling performance. In-situ Raman spectroscopic studies revealed extraction of lithium and oxide ions from the lattice followed by rearrangement of cations during the first cycle charging process and extraction of oxide ions followed by insertion of lithium ions back in the structure without any major change during the discharging process. Ex-situ Raman and microscopic measurements on the cathode before and after electrochemical cycling indicated the structural stability of the material. Studies performed on the AlPO4-coated composite cathode demonstrate the possibility of using it as next-generation cathode material for advanced lithium-ion batteries.