Hierarchically Nanostructured Electrode Materials

1 Sphere-Like Nano/Micro Hierarchical Structures for Electrode Materials 

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Hierarchically Nanostructured Electrode Materials for Lithium-Ion Batteries... 

Carbon nanostructures often serve as components in hierarchically structured electrode materials. Conductive carbon, for example, is densely packed, sp -bonded, and classified based on its dimensions. A major asset of nanostmctured carbon is its high relative surface area, which facditates an increase of both MET and DET. 

Conducting polymers can be mixed with or electrochemically deposited onto transition metal oxides to achieve better performances as electrode materials. However, the wrapping of conducting polymers on metal oxides may reduce the effective contact area between metal oxides and electrolytes. This will further impede insertion of alkali ions into metal oxides and result in poor rate performance with low specific capacitance. A rational strategy is to use conducting polymers as active electrode materials directly and optimize their structures. To this end, a hierarchically nanostructured conductive polymer hydrogel was synthesized by a facile interfacial polymerization (Shi et al., 2014). 

Kosidlo U, et al (2013) Nanocarbon based ionic actuators-a review. Smart Mater Struct 22 104022 Li J, et al (2011) Superfest-response and ultrahigh-power-density electromechanical actuators based on hierarchal carbon nanotube electrodes and chitosan. Nano Lett 11 4636-4641 Lima MD, et al (2012) Electrically, chemically, and photonically powered torsional and tensile actuation of hybrid carbon nanotube yam muscles. Science 338 928-932 Liu Q, et al (2014) Nanostructured carbon materials based electrothermal air pump actuators. Nanoscale 6 6932-6938... 

The proper design and organization of hierarchically structured electrodes optimize the bioelectronic performance and enhance mass transport of fuel to the biocatalysts. By using nanostructured materials at the interface, the relative surface area for catalyst loading is increased compared with bulk materials and the distance between catalyst and the conductive surface may be decreased to enhance DET. Nanostructured modification or functionalization of 2D surfaces may enhance power output however, the essentially planar surface can limit scalability. 

Various groups have reported promising EC electrode materials using hierarchical nanostructured carbons with well-organised pore structures, large specific surface areas and, particularly, an interconnected pore network. Portet et al. has reported 146 F g for zeolite-templated hollow-core mesoporous carbon s)mthesised by chemical vapor deposition (CVD) method [43]. Murali et al. has also reported hollow carbon capsules with specific capacitance of... 

The significant improvement in electrochemical performances of the HMC as an anode in the LIB, electrode material for the EC and cathode catalyst support for Pt in H2-fueled PEMFC are attributed to unique structural properties of the HMC. In particular, the 3D-interconnected nanostructure with hierarchical porosity, providing not only large specific surface area and high mesopore volume for high specific capacitance and homogeneous dispersion of nano-sized Pt and Pt-based alloy nanoparticles but also highly developed hierarchical macro/mesoporosity for fast mass transport. 

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