Cobalt Sulfide Confined in N-Doped Porous Branched Carbon Nanotubes for Lithium-Ion Batteries

• Main Authors: Yongsheng Zhou, Yingchun Zhu, Bingshe Xu, Xueji Zhang, Khalid A. Al-Ghanim, Shahid Mahboob
• Format: Article
• Language: English
• Published: SpringerOpen 2019-03-01
• Series: Nano-Micro Letters
• Subjects: Lithium-ion batteries; Nitrogen doping; Cobalt sulfide; Branched carbon nanotubes
• Online Access: http://link.springer.com/article/10.1007/s40820-019-0259-z

Abstract Lithium-ion batteries (LIBs) are considered new generation of large-scale energy-storage devices. However, LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability. In this work, we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes (NBNTs) for LIBs. The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAh g−1 at a current density of 0.1 A g−1, and was able to maintain a stable reversible discharge capacity of 1109 mAh g−1 at a current density of 0.5 A g−1 with coulombic efficiency reaching almost 100% for 200 cycles. The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks, the incorporation of nitrogen doping, and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.