Study On Ternary Si Based Anode Composite Mateirals For Lithium-Ion Batteries

With the exploitation and application of new energy and new materials, much effort hasbeen focused on investigation of new electrode materials. Si has a high specific capacity (4200mA·h/g) and perfect rate discharge, so it has become one of the research hotspots of anodematerials for lithium-ion batteries.In this paper, electrochemical properties of Mg-Ni-Si and Al-Ti-Si system anode compositehas been investigated. For Mg-Ni-Si system, Si content has obvious influence on theelectrochemical properties. Heat treatment can effectively increase the circulation performanceand the coulomb efficiency of higher Si content sample. When Si content (according to the moleratio) is15%, the first coulomb efficiency is64%; when Si content is30%, the first coulombefficiency is52%. When Si content is less than15%, the cycling performance reduces by7%asthe content of Si increasing by5%. When Si content is more than15%, the content of Si hasgreater effect on cycling performance. For Al-Ti-Si system, its charge-discharge curve showssamples change into amorphous from crystal after the first charging-discharging cycling. ForAl-Ti-Si system, the first coulomb efficiency is low and then the second coulomb efficiencyincreases, but reversible capacity is low. Al30Ti45Si25sample with700℃and800℃hearttreatment has good cycle performance, showing the sample heat treatment above700℃has goodcycling properties.