Facial preparation of N-doped carbon foam supporting Co3O4 nanorod arrays as free-standing lithium-ion batteries’ anode

Here, free-standing lithium-ion batteries (LIBs) anodes were fabricated through using flexible N-doped carbon foam (NCF) derived from melamine foam as substrate and current collector based on triethylamine (TEA)-assisted burning of Co(CO 3 ) 0·5 OH/NCF in air. The burning not only achieved the simple transformation from Co(CO 3 ) 0·5 OH to porous Co 3 O 4 nanorods which were arrayed on NCFs evenly, but also maintained the flexibility and integrity of NCF. The as-obtained NCF/Co 3 O 4 composites had a robust three-dimensional framework and porous structure, which improved the electron/ion transfer, enhanced contact area with electrolyte and prevented the volume inflation in discharging/charging process. In the combusting process, TEA was transformed into N and carbon atom coating on NCF and Co 3 O 4 nanorods, and eventually formed cross-linked NCF frame helpful to stabilize Co 3 O 4 nanorods. When the NCF/Co 3 O 4 composites were applied directly as free-standing LIBs’ anode, it had a higher loading mass of ∼2.5 mg cm −2 compared to traditional anode. In addition, the low charge transfer impedance and easy separation caused by the addition of traditional inactive materials were eliminated. Therefore, the flexible porous NCF/Co 3 O 4 anode without any conductive additives and binders showed the discharge capacity of 576 mAh g −1 at 1 A g −1 after 300 cycles and excellent rate capability.