Controllable synthesis of MnO2 nanostructures anchored on graphite foam with different morphologies for a high-performance asymmetric supercapacitor
Controllable synthesis of MnO2 nanostructures anchored on graphite foam with different morphologies for a high-performance asymmetric supercapacitor
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可控合成不同形貌石墨泡沫上的 MnO2 纳米结构，用于高性能不对称超级电容器
DOI：
10.1039/c7ce02108a
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发表时间：
2018-03-28
期刊：
影响因子：
3.1
通讯作者：
Ji, Junyi
中科院分区：
文献类型：
--
作者：
Lv, Xingbin;Zhang, Hualian;Ji, Junyi
通过调节KMnO 4溶液的浓度，采用简单的水热法制备了不同形貌的MnO 2纳米结构（纳米线、纳米线束和花状纳米片束）。MnO 2纳米线和纳米片都具有约10-30纳米的纳米厚度。这种“开放”的纳米结构可以促进电解质渗透并提高活性材料的利用效率。由于石墨烯/Ni泡沫（GNF）基底的高电子传导性以及大的电解质/电极接触界面，在1 M Na 2SO 4电解质中可以获得201 F g-1的比电容。在GNF和活化的微波剥离氧化石墨（a-MEGO）上组装有花状MnO 2纳米片束的非对称超级电容器分别产生44.5 W h kg−1的能量密度和50.0 kW kg−1的功率密度。这些独特且可控的MnO 2纳米结构在能量存储和传感器领域具有巨大的潜在应用。
MnO2 nanostructures with different morphologies (nanowires, nanowire bundles and flower-like nanosheet bundles) were synthesized by adjusting the concentration of KMnO4 solution using a simple and surfactant-free hydrothermal method. Both MnO2 nanowires and nanosheets have ultrathin thickness of about 10–30 nanometers. Such ‘open’ nanostructures can facilitate the electrolyte infiltration and increase the active material utilization efficiency. Owing to the high electron conductivity of the graphene/Ni foam (GNF) substrate as well as the large electrolyte/electrode contact interface, a specific capacitance of 201 F g−1 can be obtained in 1 M Na2SO4 electrolyte. An asymmetric supercapacitor assembled with flower-like MnO2 nanosheet bundles on GNF and activated microwave exfoliated graphite oxide (a-MEGO) yields an energy density of 44.5 W h kg−1 and a power density of 50.0 kW kg−1, respectively. These unique and controllable MnO2 nanostructures may have enormous potential applications in the fields of energy storage and sensors.