Synthesis and electrochemical properties of Ni doped spinel LiNi (subx)Mn (sub2-x)O(sub)4 (0 ≤ x ≤ 0.5) cathode materials for Li-Ion battery

Abstract

Spherical pristine LiMn(sub2)O(sub4) and Ni doped LiNixMn(sub2-x)O(sub)4 (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 LiN(subi0.5)Mn(sub1.5)O(sub)4 provides higher current of 10nA than pristine LiMn(sub2)O(sub4) of 0.05nA. The EIS result displays that small Ni content (x=0.1, 0.2) doping reduced the impedances of pristine LiMn(sub2)O(sub4). The composition LiN(subi0.1)Mn(sub1.9)O(sub)4 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 LiMn(sub2)O(sub4). All Ni doped LiNixMn(sub2-x)O(sub)4 (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 LiMn(sub2)O(sub)4 retains only 60% of its first cycle discharge capacity of 122 mAh/g after 50 cycles.