Electrochemical behavior of LiMn2-X-YTiXFeYO4 as cathode material for Lithium ion batteries

Solid solutions of LiMn2-X-YTiXFeYO4 (X = 0.0 <= X >= 0.1, Y= 0.05) nanoparticles were synthesized by ureaglycerol combustion method. The undoped/doped LiMn2O4 nanoparticles were characterized by XRD, FTIR, FE-SEM and electrochemical techniques. The LiMn2-X-YTiXFeYO4 spinel shows higher lattice constant of 8.279 angstrom at X = 0.10 Ti doping, while the Ti and Fe dual doped exhibits a = 8.212 angstrom. No obvious impurity phases/structural changes are observed in all the synthesized LiMn2-X-YTiXFeYO4 (X = 0.0 <= X >= 0.1, Y= 0.05) nanomaterials. The appearance of FT-IR band at similar to 603 cm(-1) evidenced the formation of Li-Ti-Mn-O bonds. Increased peak current is observed for the compound LiMn1.90Ti0.05Fe0.05O4 attributable to the improved Li+ diffusion caused by the reduced R-ct values and path lengths. LiMn1.90Ti0.05Fe0.05O4 exhibits a very small increase of 73 Omega cm(2) R-ct value even after 100th cycle, while that of 1122 Omega cm(2) for LiMn2O4. A high specific discharge capacity of 125 mA h g(-1) is retained even after 100th cycle effected by presence of Ti & Fe in the Mn site. The LiMn1.90Ti0.05Fe0.05O4 nanoparticles sample exhibit decent capacity retention of 90% at 100th cycle, and it can be able to deliver higher and constant discharge capacity and it may be a good alternative for the existing cathode materials. (C) 2014 Elsevier B.V. All rights reserved.