School of Materials Science & Engineering , Central South University , Changsha , Hunan 410083 , China.
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) , Nankai University , Tianjin 300071 , China.
ACS Appl Mater Interfaces. 2018 Mar 14;10(10):8730-8738. doi: 10.1021/acsami.7b19719. Epub 2018 Mar 5.
Three-dimensional (3D) binary oxides with hierarchical porous nanostructures are attracting increasing attentions as electrode materials in energy storage and conversion systems because of their structural superiority which not only create desired electronic and ion transport channels but also possess better structural mechanical stability. Herein, unusual 3D hierarchical MnCoO porous dumbbells have been synthesized by a facile solvothermal method combined with a following heat treatment in air. The as-obtained MnCoO dumbbells are composed of tightly stacked nanorods and show a large specific surface area of 41.30 m g with a pore size distribution of 2-10 nm. As an anode material for lithium-ion batteries (LIBs), the MnCoO dumbbell electrode exhibits high reversible capacity and good rate capability, where a stable reversible capacity of 955 mA h g can be maintained after 180 cycles at 200 mA g. Even at a high current density of 2000 mA g, the electrode can still deliver a specific capacity of 423.3 mA h g, demonstrating superior electrochemical properties for LIBs. In addition, the obtained 3D hierarchical MnCoO porous dumbbells also display good oxygen evolution reaction activity with an overpotential of 426 mV at a current density of 10 mA cm and a Tafel slope of 93 mV dec.
具有分级多孔纳米结构的三维（3D）二元氧化物作为储能和转换系统中的电极材料引起了越来越多的关注，因为它们的结构优势不仅创造了所需的电子和离子传输通道，而且具有更好的结构机械稳定性。在此，通过简便的溶剂热法结合随后在空气中的热处理，合成了异常的 3D 分级 MnCoO 多孔哑铃。所获得的 MnCoO 哑铃由紧密堆叠的纳米棒组成，具有 41.30 m² g 的大比表面积，孔径分布为 2-10 nm。作为锂离子电池（LIBs）的阳极材料，MnCoO 哑铃电极表现出高可逆容量和良好的倍率性能，在 200 mA g 的电流密度下 180 次循环后可保持 955 mA h g 的稳定可逆容量。即使在 2000 mA g 的高电流密度下，电极仍可提供 423.3 mA h g 的比容量，表现出优异的 LIBs 电化学性能。此外，所获得的 3D 分级 MnCoO 多孔哑铃还表现出良好的析氧反应活性，在 10 mA cm 的电流密度下的过电势为 426 mV，塔菲尔斜率为 93 mV dec。
