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One-Step Carbonization Synthesis of Hollow Carbon Nanococoons with Multimodal Pores and Their Enhanced Electrochemical Performance for Supercapacitors
journal contribution
posted on 2014-02-12, 00:00 authored by Jianan Zhang, Kaixi Wang, Shaojun Guo, Shoupei Wang, Zhiqiang Liang, Zhimin Chen, Jianwei Fu, Qun XuHollow
carbon capsules with multimodal pores are highly promising
for developing novel electrode materials for high-performance electrochemical
devices due to their more active sites for ion and electron transfer.
However, at present, most of the previous efforts are focused on the
multistep process for the synthesis of hollow carbon nanostructures
with individual pores. Herein, hollow carbon nanococoons (HCNCs) with
non-spherical cavity and multimodal hierarchical pores have been facilely
synthesized via a one-step carbonization of a Fe2O3/carbon precursor core/shell nanospindle at 850 °C. We
interestingly found that during the carbonization, Fe2O3 was automatically “escaped” from the inside
nanospindle, leading to the formation of new HCNCs. Most importantly,
the spindle-shaped cavity of the obtained HCNCs with high conductivity
can offer a multimodal ion diffusion pathway, which can facilitate
the reaction kinetics in a supercapacitor. As a result, the HCNCs-based
supacapacitor exhibits the capacitance of 220.0 F g–1 at a given scan rate of 5 mV s–1, 3.5 times higher
than that of hollow carbon spheres, high stability with 98% of the
initial capacity maintained even after 1000 cycles, and high rate
capability. This work provides a new and facile avenue for enhancing
performance of a HCNCs-based supercapacitor by using the non-spherical
hollow structures with multimodal pores.