In situ synthesis of ultrafine β-MnO2/polypyrrole nanorod composites for high-performance supercapacitors

We report a remarkable observation that is at odds with the established notion that β-MnO2 was regarded as an undesirable candidate for supercapacitor applications. The specific capacitance of β-MnO2 can reach as high as 294 F g−1, which is comparable to the best crystallographic structure, like α-MnO2. The key is to substantially decrease the size of β-MnO2 powders to ultra small regime. We demonstrate a facile, simple, and effective approach to synthesizing ultrafine (<10 nm in diameter) β-MnO2/polypyrrole nanorod composite powders for high-performance supercapacitor electrodes. Our observation may encourage a revisit of the other good or even bad candidate active materials if we can decrease their size to extremely small scales. In addition, the proposed synthetic mechanism and the developed synthetic strategy may provide design guidelines in synthesizing other energy storage materials toward ultrafine 1D nanostructures.

[1]  F. Favier,et al.  Microstructural effects on charge-storage properties in MnO2-based electrochemical supercapacitors. , 2008, ACS applied materials & interfaces.

[2]  Y. Gogotsi,et al.  Materials for electrochemical capacitors. , 2008, Nature materials.

[3]  S. Devaraj,et al.  Effect of Crystallographic Structure of MnO2 on Its Electrochemical Capacitance Properties , 2008 .

[4]  Yadong Li,et al.  Selected-Control Hydrothermal Synthesis of α- and β-MnO2 Single Crystal Nanowires , 2002 .

[5]  Xin Wang,et al.  Shape-Controlled Synthesis of One-Dimensional MnO2 via a Facile Quick-Precipitation Procedure and its Electrochemical Properties , 2009 .

[6]  Michael M. Thackeray,et al.  Manganese oxides for lithium batteries , 1997 .

[7]  F. Béguin,et al.  Carbon materials for the electrochemical storage of energy in capacitors , 2001 .

[8]  Jim P. Zheng,et al.  A New Charge Storage Mechanism for Electrochemical Capacitors , 1995 .

[9]  Ran Liu,et al.  MnO2/poly(3,4-ethylenedioxythiophene) coaxial nanowires by one-step coelectrodeposition for electrochemical energy storage. , 2008, Journal of the American Chemical Society.

[10]  H. Thomas Hahn,et al.  Fabrication and characterization of iron oxide nanoparticles filled polypyrrole nanocomposites , 2009 .

[11]  C. M. Li,et al.  Well-Aligned Cone-Shaped Nanostructure of Polypyrrole/RuO2 and Its Electrochemical Supercapacitor , 2008 .

[12]  Ye Hou,et al.  Design and synthesis of hierarchical MnO2 nanospheres/carbon nanotubes/conducting polymer ternary composite for high performance electrochemical electrodes. , 2010, Nano letters.

[13]  Zhanhu Guo,et al.  Conductive Polypyrrole/Tungsten Oxide Metacomposites with Negative Permittivity , 2010 .

[14]  Pooi See Lee,et al.  Facile coating of manganese oxide on tin oxide nanowires with high-performance capacitive behavior. , 2010, ACS Nano.

[15]  Jim P. Zheng,et al.  Hydrous Ruthenium Oxide as an Electrode Material for Electrochemical Capacitors , 1995 .

[16]  S. Ardizzone,et al.  "Inner" and "outer" active surface of RuO2 electrodes , 1990 .

[17]  S. Trasatti.  Physical electrochemistry of ceramic oxides , 2010 .

[18]  Chi-Chang Hu,et al.  Hydrothermal Synthesis of Hydrous Crystalline RuO2 Nanoparticles for Supercapacitors , 2004 .

[19]  Mathieu Toupin,et al.  Charge Storage Mechanism of MnO2 Electrode Used in Aqueous Electrochemical Capacitor , 2004 .

[20]  Juan Li,et al.  Preparation and electrochemistry of one-dimensional nanostructured MnO2/PPy composite for electrochemical capacitor , 2010 .

[21]  Qiang Wang,et al.  Polypyrrole/Silicon Carbide Nanocomposites with Tunable Electrical Conductivity , 2010 .

[22]  Wendy G. Pell,et al.  Self-discharge and potential recovery phenomena at thermally and electrochemically prepared RuO2 supercapacitor electrodes , 1997 .

[23]  Hong Xu,et al.  Evolution of Physical and Electrochemical Properties of Polypyrrole during Extended Oxidation , 1992 .