Electrochemical and Structural Properties of Li[LixNiyMn1-x-y]O2 Cathode Materials for Lithium Secondary Batteries

초록

The layered lithium metal oxides such as LiCoO2, LiNiO2 and LiMnO2 have been of great interesting as positive electrode materials for secondary lithium batteries. Among these, LiMnO2 is one of the most promising cathode materials due to low cost, abundance, and nontoxicity [1]. The search for layered LiMnO2 is being pursued, but the materials tend to transform to the more stable spinel phase during cycling. Recently, some research groups have studied to stabilize layered structure by using solid solution between Li2MnO3 and LiMO2 (M = Cr, Ni, Co) such as Li[Li(1-2x)/3 Nix Mn(2-x)/3]O2 and Li[Li(1-x)/3Co(Cr)xMn(2-2x)/3]O2 [2,3]. In this system, M is the redox-active species from Mn+ to M(n+1)+ or M(n+2) or M(n+3)+, while Li1/3Mn2/3 clusters with tetravalent manganese act as inert matrix. In this work, we report the structural and electrochemical properties of a layered Li[LixNiyMn1-x-y]O2 materials.