Investigation of Capacity Fading Mechanism on Nanocrystalline LiNi_0.5Mn_0.5O₂ Synthesized by Autocombustion Technique

As potential cathode material for lithium ion batteries, nanocrystalline LiMn_0.5Ni_0.5O₂ is successfully synthesized by low cost solution based combustion synthesis route. Structural and morphological characterizations of these materials are carried out at pristine state as well as after long cycling to investigate the changes that occur during cycling. Extensive electrochemical characterizations such as galvanostatic charge discharge-cycling, cyclic voltammetry, electrochemical impedance spectroscopy are reported for this layered cathode materials. A reversible capacity of ~ 100 mAhg⁻¹ with 20% capacity fading after 100 cycles without any structural change in bulk of the materials and moderate rate performance at different current rate are observed in the developed cathode material. A systematic change in electrochemical impedance taken at different state of charge and at different cycle and calculation of lithium ion diffusion coefficient suggest that any deterioration in electrochemical properties is mainly due to the side reaction and formation of solid electrolyte interface (SEI) layer on surface of the particle, not due to the change in bulk of the materials.