Preparation of porous carbon spheres from porous starch

Porous carbon spheres were prepared through two steps: (a) coating a Na2SnO3 or Na2SiO3 protective layer onto the surface of porous starch, and then (b) carbonizing the products. The carbon spheres were characterized with X-ray diffraction, scanning electron microscopy and Raman spectroscopy. The porous carbon spheres inherited the morphology and texture of the porous starch during carbonization. A mechanism for the morphology preservation of the porous starch is proposed. The electrochemical performance of carbon spheres as anode material of lithium ion battery was detected. It showed that the carbon spheres maintain a specific capacity of 513 mAh/g after 50 cycles.