Synthesis of morphology controllable free-standing Co3O4 nanostructures and their catalytic activity for Li-O2 cells
Synthesis of morphology controllable free-standing Co3O4 nanostructures and their catalytic activity for Li-O2 cells
复制标题
形貌可控自支撑Co3O4纳米结构的合成及其对Li-O2电池的催化活性
DOI：
10.1016/j.electacta.2019.03.188
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发表时间：
2019
影响因子：
6.6
通讯作者：
Ting-feng Yi
中科院分区：
文献类型：
--
作者：
Hong-bo Huang;Shao-hua Luo;Cai-ling Liu;Qing Wang;Yu-chun Zhai;Ting-feng Yi
以六水合硝酸钴为钴源，尿素为沉淀剂，采用简单的水热法在泡沫镍上合成了自支撑Co 3 O 4。详细研究了尿素对材料结构和电化学性能的影响。随着尿素含量的增加，自支撑Co 3 O 4的形貌由六方纳米片转变为纳米片，最后转变为纳米片/纳米线混合结构。这种混合结构由多孔纳米片和锚定在纳米片边缘的短纳米线组成，这可以提高电解质和O-2的扩散速率，并为O-2还原和释放反应提供更多的活性位点。当用作Li-O-2电池的自支撑阴极时，纳米片/纳米线混合结构比其他结构显示出更好的性能。该材料在0.1mA cm（-2）时的比容量高达5958 mA h g（-1），循环寿命长达108次，极限容量为500 mA h g（-1），放电产物形貌独特。
Free-standing Co3O4 on nickel foam is synthesized by a simple hydrothermal route, using cobalt nitrate hexahydrate as the cobalt source, and urea as the precipitator. The effects of urea on the structural and electrochemical characteristics are investigated in detail. As the urea increased, the morphology of the free-standing Co3O4 turns from hexagonal nanosheets to nanoflakes, and finally turns to nanoflakes/nanowires hybrid structure. This hybrid structure is made up of ultrathin porous nanoflakes, and short nanowires anchored at the edge of the nanoflakes, which may enhance the diffusion rate of the electrolyte and O-2 and provide more active sites for both O-2 reduction and evolution reactions. When applied as a free-standing cathode for the Li-O-2 cells, it shows better performance for the nanoflakes/nanowires hybrid structure than the others. It exhibits a high specific capacity of 5958 mA h g(-1) at 0.1 mA cm(-2), a long cycle life of 108 cycles with a limited capacity of 500 mA h g(-1), and unique morphology of the discharge products.