Comparative performance of birnessite-type MnO₂ nanoplates and octahedral molecular sieve (OMS-5) nanobelts of manganese dioxide as electrode materials for supercapacitor application

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• 作者：Xiong Zhang ; Xianzhong Sun ; Haitao Zhang ; Chen Li ; Yanwei Ma ; ^{ywma@mail.iee.ac.cn" class="auth_mail}
• 关键词：MnO2 ; Supercapacitor ; Crystalline structure ; Specific capacitance
• 刊名：Electrochimica Acta
• 出版年：20 June 2014
• 年：2014
• 卷：132
• 期：Complete
• 页码：315-322
• 全文大小：2882 K

文摘

Na-birnessite-type MnO₂ (Na-OL-1) nanoplates and sodium manganese dioxide nanobelts with a 2 × 4 tunnel (Na-OMS-5) were synthesized by a hydrothermal method via one-pot oxidation reaction at 120 and 200 °C, respectively. The microstructure, morphology, and thermal stability of the MnO₂ products were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, simultaneous thermogravimetric-mass spectrometry, and N₂ adsorption–desorption measurements. Their electrochemical performance was investigated in order to understand the sodium ions intercalation − deintercalation processes in the lamellar or tunnel structure of MnO₂. Na-OL-1 nanoplates exhibited a specific capacitance of 308 F g⁻¹ at a current density of 0.2 A g⁻¹, which is much higher than that of Na-OMS-5 nanobelts (141 F g⁻¹). Moreover, the Na-OL-1 nanoplates showed a good rate capability and electrochemical stability, suggesting that it is a promising electrode material for supercapacitors.