Journal of Power Sources, Vol.158, No.1, 620-626, 2006
The effect of compositional change of transition metals on the electrochemical behavior of layered LiMO2 (M = LiwNixCoyMnz) solid solutions
Seven compositions of LiMO2 (M = LiwNixCoyMnz) (w = 1/15 - 1/6; x = 0 -3/10; y = 1/5 - 1/2; z = 13/30 - 1/3; i.e. w + x + y + z = 1) solid solutions were synthesized using the sol-gel method with the following end members LiCoO2, Li2MnO3(Li[Li1/3Mn2/3]O-2), and Li[Ni0.5Mn0.5]O-2. The electrochemical behavior of the solid solutions was analyzed for the various compositions of metals in transition metal sites. All synthesized particles were semi-spherically shaped with a layered structure. When the content of lithium and cobalt was reduced (while the other metals were increased), the lattice parameters, a and c, decreased and were accompanied by a shift in the Raman spectrum. The cycling studies reveal that the compound, Li[Li1/12Ni1/4Co1/4Mn5/12]O-2 was found to be optimal in voltage and from a stability point of view. (c) 2005 Elsevier B.V. All rights reserved.