Designing and preparing carbon anode materials modified with N and Fe-nanoparticle: Creating the interior electric field to improve their electrochemical performance. (1st July 2021) - Li, Qiongguang
Abstract: The increasing market demand calls for novel anode materials with low cost, high capacity, good rate performance, and high cycle stability. Here we report a facile method for preparing chitosan-derived and N-doped carbon composite (Fe-CDNC) decorated with Fe nanoparticles (NPs) as an efficient carbon anode material. The prepared Fe-CDNC composite could deliver a high reversible lithium capacity of 770 mAh g −1 at 100 mA g −1, much higher than that of both the bare CDNC (426 mAh g −1 ) and the theoretical capacity of commercial graphite (372 mAh g −1 ). The retention of lithium and sodium capacity was 95.5% after 10000 cycles and 98.7% after 5000 cycles at 2000 mA g −1, respectively, and thus the lithium and sodium capacity loss rates were 0.00045% and 0.00026% per cycle, respectively. Density functional theory calculations revealed that the strong coupling between the Fe NPs and the N-doped carbon layer via Fe-N bond formation contributed to constructing a built-in electric field, which boosted ions/charge diffusion dynamics, leading more lithium ions to be inserted/extracted to carbon layer during the lithiation/delithiation processes. Therefore, the Fe-CDNC composite performed an outstanding rate performance, cycle stability, and high reversible capacity. This work is promising to develop novel carbon anode materials for high-energy storage devices.