Silicon based materials have been studied as alternative anode materials for lithium ion batteries due to high theoretical capacities(4200 mAh/g)and high energy density.However silicon based materials have several problems such as drastic volume change(>300%),and low electrical conductivity of silicon itself.Doping can be a solution to improve electrical conductivity of silicon itself.Phosphorous doping in silicon nanoparticles had been expected to enhance the lithium ion batterys performance due to improved conductivity of silicon nanoparticles.