Amorphous carbon shell on Si particles fabricated by carbonizing of polyphosphazene and enhanced performance as lithium ion battery anode

A novel strategy was employed to introduce a carbon layer on Si particle to overcome the intrinsic poor electrical conductivity and significant volume change. The carbon layer was fabricated by forming polyphosphazene coating through a facile precipitation polymerization method, followed by carbonization. As a result of formation of core-shell structure, the Si anode exhibited improved cycling stability (740 mA h/g remained after 100 cycles) and rate capability (300 mA h/g at a rate 2C). In addition, 99% coulombic efficiency was remained after 100 cycles.