Carbon paper substrate for silicon–carbon composite anodes in lithium-ion batteries

We have developed a new Si-based anode for lithium secondary batteries consisting of a carbon paper substrate and Si/C composite deposited on it (Si/C/CP electrode). The Si/C composite was formed by pyrolysis of a slurry consisting of Si power and THF solution of PVC as the carbon precursor. The electrode contains no additional conductive carbon and binder, which supports the tight contact among the Si particle, pyrolytic carbon and carbon paper. The Si/C/CP electrode with the three-dimensional carbon fiber framework of the carbon paper was also advantageous to absorb severe volume changes of silicon particles. The electrode performance revealed that the Si/C/CP electrode prepared from the mixture of Si and PVC with the ratio of 10:90 by weight had a quite high initial capacity of 1720 mAh g−1 and initial Coulombic efficiency of 90%, and also exhibited excellent capacity retention with a reversible capacity of 1200 mAh g−1 even after 100 cycles.