کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
187334 | 459640 | 2013 | 7 صفحه PDF | دانلود رایگان |
• Co3O4 nanocapsules with onion-like carbon shell have been synthesized.
• Co3O4 nanocapsules deliver an initial discharge capacity of 1467.6 mAh g−1 at 0.5 C.
• Co3O4 nanocapsules maintain a reversible capacity of 1026.9 mAh g−1 after 50 cycles.
• Onion-like carbon shells can improve the electrochemical performance of Co3O4.
The synthesis and characterization of core/shell-type Co3O4/C nanocapsules for application as anode material in lithium ion batteries are reported in this paper. The synthesis process involves the preparation of Co/C nanocapsules using a modified arc-discharge method and the annealing of the Co/C nanocapsules at 300 °C for 2 h in air. The as-synthesized products show a spherical shape and a core/shell-type structure in which a Co3O4 nanoparticle core of diameter 10–30 nm is encapsulated by an onion-like carbon shell of thickness approximately 1 nm. The Co/C nanocapsules can be stable below 130 °C, and be oxidized above 205 °C in air. The Co3O4/C nanocapsules deliver an initial discharge capacity of 1467.6 mAh g−1 at 0.5 C and maintain a high reversible capacity of 1026.9 mAh g−1 after 50 charge–discharge cycles, much higher than the Co3O4 nanoparticles (471.5 mAh g−1). A postmortem analysis of the Co3O4 and Co3O4/C anodes subjected to prolonged cycling reveals the existence of a lower degree of surface cracking and particle breakage in the Co3O4/C anode than the Co3O4 anode. The improved electrochemical performance and structural stability in the Co3O4/C nanocapsules are attributed to the enhanced electrical conductivity and structural buffering provided by the onion-like carbon shell.
Co3O4 nanocapsules with the onion-like carbon shells were synthesized. As anode materials for lithium ion battery, the Co3O4 nanocapsules deliver an initial discharge capacity of 1467.6 mAh g−1 at 0.5 C and maintain a high reversible capacity of 1026.9 mAh g−1 after 50 cycles.Figure optionsDownload as PowerPoint slide
Journal: Electrochimica Acta - Volume 100, 30 June 2013, Pages 140–146