Carbon nanotube coating silicon doped with Cr as a high capacity anode

Effects of dopant and coating carbon nanotube on anodic performance of Si were studied for metallic anode Li ion rechargeable battery with large capacity. Although the large Li intercalation capacity higher than 1500 mAh g−1 is exhibited on pure Si, it decreased drastically with increasing cycle number. Increasing the electrical conductivity by doping Cr or B is effective for increasing the initial capacity and the cycle stability of Si for Li intercalation. Coating semiconductive Si with the carbon nanotube by decomposition of hydrocarbon is effective for increasing the cycle stability, though the initial Li intercalation capacity slightly decreased. Conducting binder is also important for increasing the cycle stability and it was found that Li intercalation capacity higher than 1500 mAh g−1 can be sustained by using poly vinyliden fruolide. Consequently, reversible Li intercalation capacity of 1500 mAh g−1 was successfully sustained after 10th cycles of charge and discharge by doping Cr and coating with carbon nanotube.