A Novel Fabrication Technique for Producing Dense Li[Ni[sub x]Li[sub (1∕3–2x∕3)]Mn[sub (2∕3−x∕3)]]O[sub 2], 0≤x≤1∕2

Abstract

Using a novel synthesis technique similar to the Columbite method, we have prepared materials from the series Li[NixLi(1∕3–2x∕3)Mn(2∕3−x∕3)]O2Li[NixLi(1∕3–2x∕3)Mn(2∕3−x∕3)]O2 , 0⩽x⩽1∕20⩽x⩽1∕2 , with high density and average particle size greatly in excess of 1μm1μm , without the aid of a sintering agent. The structure of NixMn(1−x)(OH)2NixMn(1−x)(OH)2 precursors, as a function of temperature and composition, was studied in detail. These materials phase-separate into mixed oxides at approximately 500°C500°C for most compositions, but compositions with x⩾3∕14x⩾3∕14 convert to single-phase spinel upon further heating. This allows for the production of a single-phase precursor with a homogeneous cation distribution and large particle size and density. By reacting these mixed-metal oxide spinel precursors with LiOH·H2OLiOH·H2O , we have prepared dense Li[NixLi(1∕3–2x∕3)Mn(2∕3−x∕3)]O2Li[NixLi(1∕3–2x∕3)Mn(2∕3−x∕3)]O2 materials without heating over 900°C900°C . These dense materials will allow production of electrodes for advanced LiLi -ion cells with greater volumetric energy density.