Blends of silicon with various organic precursors were pyrolyzed for constructing the Si-containing disordered carbon and the effects of the amorphous carbon on the electrochemical performances of the resulting Si/C composites were investigated. It was found that the pyrolysis of poly(vinylidene fluoride) provided an appropriate carbon matrix to suppress the pulverizing of Si by the volume changes during lithium intercalation and extraction. Accordingly, nanosized Si was dispersed within the pyrolyzed poly(vinylidene fluoride). The porous composite exhibited a specific capacity of approximately 660mAhg−1 with a 75% capacity retention after 50 cycles. The cycling stability is a substantial improvement over nanosized silicon where a rapid drop in capacity occurred within a few cycles.