Phenolic resin derived porous carbon/α-Fe2O3 composites with improved lithium storage performance

Porous carbons with large specific surface area and high structural stability are conducive to Li+ diffusion and cycling performance of lithium ion batteries. In this paper, porous carbon/α-Fe2O3 composites were in situ synthesized using water soluble phenolic resin as carbon precursor and environmentally benign NaCl as porogen. The interaction between the metal ions and hydroxyl groups in the resin facilitates the self-assembly of the precursors. The presence of NaCl enables the uniform dispersion of ferrous gluconate in the phenolic resin and prevents the aggregation of α-Fe2O3 during the later thermal treatment. When applied as anode materials for lithium ion batteries, the porous carbon provides short diffusion pathways for Li+ ions and adequate buffer space to accommodate the volume change of α-Fe2O3 during the discharge/charge process, leading to a high reversible capacity of 1272 mAh g−1 at 100 mA g−1 after 200 cycles, which is much higher than that of carbon/α-Fe2O3 without addition of NaCl. This strategy provides a simple and low-cost way for the mass production of novel anode materials of lithium ion batteries.