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LiCox Mn2-x O4 cathode materials for lithium ion batteries were synthesized by mechanical activation-solid state reaction at 750℃for 24 h in air atmosphere,and their crystal structure,morphology,element composition and electrochemical performance were characterized with XRD,SEM,ICP-AES and charge-discharge test.The experimental results show that all samples have a single spinel structure,well formed crystal shape and uniformly particle size distribution.The lattice parameters of LiCo x Mn 2-x O 4 decrease and the average oxidation states of manganese ions increase with an increase in Co content.Compared with pure LiMn 2 O 4 ,the LiCo x Mn 2-x O 4 (x=0.03-0.12)samples show a lower special capacity,but their cycling life are improved.The capacity loss of LiCo 0.09 Mn 1.91 O 4 and LiCo 0.12 Mn 1.88 O 4 is only 1.85%and 0.95%,respectively,after the 20th cycle.The improvement of the cycle performance is attributed to the substitution of Co at the Mn sites in the spinel structure,which suppresses the Jahn-Teller distortion and improves the structural stability.
LiCox Mn2-x O4 cathode materials for lithium ion batteries were synthesized by mechanical activation-solid state reaction at 750 ℃ for 24 h in air atmosphere, and their crystal structure, morphology, element composition and electrochemical performance were characterized with XRD, SEM, ICP -AES and charge-discharge test. The experimental results show that all samples have a single spinel structure, well formed crystal shape and uniform particle size distribution. The lattice parameters of LiCo x Mn 2-x O 4 decrease and the average oxidation states of manganese ions increase with an increase in Co content. Compared with pure LiMn 2 O 4, the LiCo x Mn 2-x O 4 (x = 0.03-0.12) samples show a lower special capacity, but their cycling life are improved. capacity loss of LiCo 0.09 Mn 1.91 O 4 and LiCo 0.12 Mn 1.88 O 4 is only 1.85% and 0.95% respectively, after the 20th cycle. The improvement of the cycle performance is attributed to the substitution of Co at the Mn sites in the spinel structure, which sup presses the Jahn-Teller distortion and improves the structural stability.