SYNTHESIS AND PROPERTIES OF Li2MnSiO4 COMPOSITE CATHODE MATERIAL FOR SAFE Li-ION BATTERIES

Abstract

Lithium silicates Li 2 MnSiO 4 (where M is a 3d metal) with their theoretical capacity up to 333 mAh⋅g-1 and high chemical stability, thanks to a presence of strong covalent bonds Si – O , seem to be a good potential cathode material for Li -ion batteries. The main drawback of those materials is their low electric conductivity which can be enhanced by coating the material with conductive carbon layer (CCL). This work concerns the synthesis of CCL / Li 2 MnSiO 4 composite material and investigation of its physicochemical properties. The material was successfully produced using sol-gel Pechini method. In order to find the best way of receiving Li 2 MnSiO 4 product various synthesis conditions were applied. CCL / Li 2 MnSiO 4 composite was produced in a one-step process using organic precursor matrix as a source of carbon. Both Li 2 MnSiO 4 material and CCL/ Li 2 MnSiO 4 composite were investigated using thermal analysis (EGA-TGA/DTG/SDTA), X-ray diffraction (XRD) and electrical conductivity measurements to find the relations between structure, morphology and electrochemical properties.