The pitch-based silicon-carbon composites fabricated by electrospraying technique as the anode material of lithium ion battery.

Silicon is regarded as one of the most promising anode materials for high performance lithium-ion battery (LIB) due to its high theoretical specific capacity. However, the low electrical conductivity and the severe volume change during charging and discharging process result in poor cyclic performance. In this study, a low cost, high-purity silicon powder from the sawing waste in photovoltaic industry was used as the active material. Pitch from petroleum residue was used as carbon source to provide a good conductive pathway and prevent the drastic volume changes of Si. The pitch-based silicon-carbon composites with a porous structure were fabricated by electrospraying technique followed by a sequence of thermal processes. The results of the charge/discharge showed that the 100th charge capacity of 1515 mAh/g at 0.2 C with the retention of 73.95% while the 200th charge capacity of 929 mAh/g at 0.5 C with the retention of 70.61% (Pitch-Si-0.5) can be obtained. On the other hand, the sample with medium content of Si showed charge capacity of 522 mAh/g at 0.5 C with the extremely high retention of 94.99% after 200 cycles. The rate capability indicated that the soft carbon derived from pitch provided a good rate capability because of its amorphous structure. We demonstrated that industrial wastes can form a superior anode material for LIB application. • Spherical silicon-carbon composite was formed as an anode material for LIB. • Silicon was from the waste of the photovoltaic industry and the source of the carbon is petroleum pitch. • The composite demonstrated an excellent capacity and stability (1515 mAh/g at 0.2C, 73.95% retention at 200th cycle). [ABSTRACT FROM AUTHOR]