Synthesis and Electrochemical Properties of Ni Doped Spinel LiNixMn2-xO4 (0 ≤ x ≤ 0.5) Cathode Materials for Li-Ion Battery

Abstract

Spherical pristine LiMn2O4 and Ni doped LiNixMn2-xO4 (x=0.1, 0.2, 0.3, 0.4, 0.5) cathode materials for lithium ion battery with high first cycle discharge capacity and excellent cycle performance were synthesized using the solution-combustion technique. XRD analysis revealed peak shift towards higher angle and lattice shrink as a result of Ni doping. CSAFM result confirms LiNi0.5Mn1.5O4 provides higher current of 10nA than pristine LiMn2O4 of 0.05nA. The EIS result displays that small Ni content (x=0.1, 0.2) doping reduced the impedances of pristine LiMn2O4. The composition LiNi0.1Mn1.9O4 exhibits higher capacity and better cycleability than other Ni content compositions. Charge/discharge cycling result shows that Ni substitution substantially improved the capacity retention of LiMn2O4. All Ni doped LiNixMn2-xO4 (x= 0.1, 0.2, 0.3,0.4, 0.5) compositions are able to retain 99% of their respective first cycle discharge capacities, whereas LiMn2O4 retains only 60% of its first cycle discharge capacity of 122 mAh/g after 50 cycles.