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 urea-glycerol combustion method. The undoped/doped LiMn2O4 nanoparticles were characterized by XRD, FT-IR, FE-SEM and electrochemical techniques. The LiMn2−X−YTiXFeYO4 spinel shows higher lattice constant of 8.279 Å at X = 0.10 Ti doping, while the Ti and Fe dual doped exhibits a = 8.212 Å. 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 ∼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 Rct values and path lengths. LiMn1.90Ti0.05Fe0.05O4 exhibits a very small increase of 73 Ω cm2 Rct value even after 100th cycle, while that of 1122 Ω cm2 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.