Cobalt Carbonate/ and Cobalt Oxide/Graphene Aerogel Composite Anodes for High Performance Li-Ion Batteries

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• 作者：Mohammad Akbari Garakani ; Sara Abouali ; Biao Zhang ; Curtis Alton Takagi ; Zheng-Long Xu ; Jian-qiu Huang ; Jiaqiang Huang ; Jang-Kyo Kim
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：November 12, 2014
• 年：2014
• 卷：6
• 期：21
• 页码：18971-18980
• 全文大小：696K
• ISSN：1944-8252

文摘

Nanocomposites consisting of ultrafine, cobalt carbonate nanoneedles and 3D porous graphene aerogel (CoCO₃/GA) are in situ synthesized based on a one-step hydrothermal route followed by freeze-drying. A further heat treatment produces cobalt oxide nanoparticles embedded in the conductive GA matrix (Co₃O₄/GA). Both the composite anodes deliver excellent specific capacities depending on current density employed: the CoCO₃/GA anode outperforms the Co₃O₄/GA anode at low current densities, and vice versa at current densities higher than 500 mA g^鈥?. Their electrochemical performances are considered among the best of similar composite anodes consisting of CoCO₃ or Co₃O₄ active particles embedded in a graphene substrate. The stable multistep electrochemical reactions of the carbonate compound with a unique nanoneedle structure contribute to the excellent cyclic stability of the CoCO₃/GA electrode, whereas the highly conductive networks along with low charge transfer resistance are responsible for the high rate performance of the Co₃O₄/GA electrode.

Keywords:

graphene aerogel; cobalt carbonate; cobalt oxide; hydrothermal process; anode; Li-ion battery