Hierarchical Co@C Nanoflowers: Synthesis and Electrochemical Properties as an Advanced Negative Material for Alkaline Secondary Batteries

详细信息    查看全文

• 作者：Li Li ; Jianmin Ma ; Zichao Zhang ; Bingqiang Cao ; Yijing Wang ; Lifang Jiao ; Huatang Yuan
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：November 4, 2015
• 年：2015
• 卷：7
• 期：43
• 页码：23978-23983
• 全文大小：391K
• ISSN：1944-8252

文摘

Hierarchical Co@C nanoflowers have been facilely synthesized via a simple route based on a low-temperature solid-phase reaction. The obtained hierarchical Co@C nanoflowers, each constructed of a number of nanosheets, display a three-dimensional architecture with an average grain size of about 300 nm. The electrochemical properties of the Co@C nanoflowers as the negative material for Ni/Co cells have been systemically researched. In particular, Co@C material exhibits high discharge-specific capacity and good cycling stability. The discharge-specific capacity of our Co@C-3 electrode can reach 612.1 mA h g^鈥?, and the specific capacity of 415.3 mA h g^鈥? is retained at a current density of 500 mA g^鈥? after 120 cycles, indicating its great potential for high-performance Ni/Co batteries. Interestingly, the as-synthesized Co@C electrode also exhibits favorable rate capability. These desirable properties can be attributed to porous pathways, which allow fast transportation of ions and electrons and easy accessibility to the electrolyte. The dominant electrochemical mechanism of Co@C can be attributed to the reduction鈥搊xidation reaction between metallic cobalt and cobalt hydroxide in alkaline solution.