Phenolic Resin-coated Porous Silicon/carbon Microspheres Anode Materials for Lithium-ion Batteries

Porous silicon/carbon (Si/C) anode materials for Lithium-ion batteries was synthesized successfully by hydrochloric acid etching and calcination method using micron Si-Al alloy as silicon source and phenolic resin as carbon source. The microstructure and morphology were characterized by XRD, SEM, TEM, XPS and BET. The electrochemical performance were measured by constant current charge-discharge test and EIS. The results show that Si/C is porous structure and its pores are distributed between 1 and 6 nm. The specific discharge specific capacity of Si/C is 1287.0 mAh/g at a current density of 100 mA/g after 50 cycles, corresponding to the capacity retention of 91.0 % (for the second cycle). Si/C delivers a high specific discharge capacity of 605.9 and 359.0 mAh/g at 1 A/g and 2 A/g, respectively. The lithium ion diffusion coefficient of Si/C is 5.98 × 10− 11 cm2 s− 1, which is higher than that of 7.57 × 10− 12 cm2 s− 1 for porous Si.