| 초록 |
Edge-NFx (x=1 or 2) protected graphitic nanoplatelets (NFGnPs) are synthesized for the first time as a stable anode material for lithium storage. The NFGnPs are prepared by ball-milling graphite in the presence of nitrogen trifluoride gas. The average grain size of the NFGnPs is dramatically reduced compared to the starting graphite. The ball-milling effectively unzips graphitic C-C bonds, which form edge C-NFx bonds and delaminate the graphite layers into a few layered NFGnPs. The resulting NFGnPs have a large specific surface area (671.0 m2g-1). Because of their large specific surface area, the NFGnPs display high average reversible capacities of 850.5, 722.4, 576.4, 482.0, 369.1, 229.7, 127.5 mAhg-1 at 0.2, 0.5, 1, 2, 5 and 10 C, respectively. More importantly, due to the edge protection provided by the stable C(C)=NF1 bonds (pseudo-aromatic), the NFGnPs maintain a high reversible charge capacity of 421.6 mAhg-1 at 2 C, with an initial capacity retention of 78.3% after 200 cycles. |
