Nanostructure and Electrochemical Performance

Li, Q., Liu, L, Zou, J., Chunder, A., Chen, Y., Zhai, L., 2011b. Synthesis and electrochemical performance of multi-walled carbon nanotube/polyaniline/Mn02 ternary coaxial nanostructures for supercapacitors. J. Power Sources 196, 565-572. 

Shivakumara, S., T. R. Penki, and N. Munichandraiah. 2014. Preparation and electrochemical performance of porous hematite (a-Fe203) nanostructures as supercapacitor electrode material. Journal of Solid State Electrochemistry 18 1057-1066. 

Zhang, Y Sun, C.S., and Zhou, Z. (2009) Sol-gel preparation and electrochemical performances of LiFei/gMni/gCoi/gPOVC composites with core-shell nanostructure. Electrochem. Commun., 11 (6),... 

Work on the nanostructuring of electrodes with carbon nanotubes by Gooding and coworkers [96, 97] has demonstrated that superior electrochemical performance can be achieved with carbon nanotubes that are vertically aligned compared with being... 

A relatively high reversible capacity (372mAh/g, i.e., one lithium for six carbon atoms in standard conditions) at a potential close to metallic lithium and a moderate irreversible capacity can be obtained with graphite-based anodes. A higher degree of reversible lithium insertion than in graphite, but also an important irreversible capacity, is observed with various kinds of nanostructured carbons. Therefore, an intensive research effort is focused on the optimization of the anodic carbon materials, with the objectives to enhance the reversible capacity and to reduce as much as possible the irreversible capacity and hysteresis, which are often important drawbacks of these materials. The next section will discuss the correlations between the electrochemical performance of nanostructured carbons and their nanotexture/structure and surface functionality. Taking into account the key parameters that control the electrochemical properties, some optimizations proposed in literature will be presented. 

We have already shown here that large surface areas translate into enhanced electrochemical performance and, from this perspective, nanostructures are also very important for fuel cell devices [8,70,88-90], particularly as regards the catalyst part of the cell where the oxygen reduction reaction can only occur in spatially confined regions [8,70,88-90]. 

Abstract There are noteworthy developments in nanotechnology and its relevance to the energy field. Fuel cells especially benefit from electrodes and membrane electrolytes with nanostructured and therefore enlarged surfaces. Fuel cells also derive benefits from the development of nanoparticles and nanombes for catalytic application, allowing also study of the molecular electrochemical behaviour. In this chapter we describe the impact of nanotechnology in the performance of the different components of the fuel cell as well as the impact of nanotechnology in the electrochemistry process. 

An alternative approach to improve the electrochemical performance of a TMO anode is the preparation of nanostructures consisting of an inert but conducting metallic core surrounded by a shell of a selected TMO. For this purpose, special synthetic routes allow the hierarchical separation of phases. Thus, the use of electrostatic spray deposition led to the formation CoO/Co composite thin films consisted of hollow spherical particles delivering a high reversible capacity of 1182.1 mAhg" at 70th cycle and retaining 69.5% of the initial capacity at 10 C [53]. 

Gao et al demonstrated the electrochemical synthesis of layer-by-layer (LBL) rGO/PANI nanocomposites for electrochemical applications [100]. The rGO/PANI nanocomposites consist of a well-compact LBL stacking nanostructure. The improved electrochemical performances of the rGO/ PANI nanocomposites can be attributed to the synergistic effect between the two components. Wei et al prepared GO/PANI nanocomposites by the electropolymerization of aniline onto the GO-coated ITO glass slides [131]. The UV-visible spectra of PANI and GO/PANI nanocomposites were recorded at different potentials. A characteristic band at 750 nm is... 

Due to the enhanced conductivity and consequent improved electrochemical performance, the cathode materials of conjugated polymers/ inorganic have attracted much attention in a wide range, and some novel nanostructures have been recently proposed. Mai et al. reported the preparation of coaxial or triaxial nanowires of MoO and AgVO coated with conducting PTh or PANI based on the in situ polymerization method [29,76], and the capacity retention rates were significantly enhanced due... 

This retaining capability was highly superior to the nanostructured SnO, e.g., hollow nanoboxes and nanosheets [109,110]. The improvement in electrochemical performance should be ascribed to the configuration of SnO /PPy nanocomposites, which offered three distinct advantages. Firstly, the 3D reticular PPy nanowires functioned as the structural support and allowed the convenient gathering and delivering for Fi+ and electron. Secondly, the nanosize SnO was favorable for volume accommodation which thereby resulted in the impressive cycling stability. Thirdly, the 3D porous nature of the nanocomposites was capable of complete penetration of electrolyte which improved the electrochemical reaction dynamics. 

The electrochemical performances of the solid-state supercapacitors are similar to the ones obtained in a liquid electrol de. Owing to the nanostructure nature of the active materials, an effective wettability by the electrotyte and a limited diffusion length of the doping ions within the pol3mier structure were observed however, environmental parameters and liber diameter reduction can be improved in order to produce more efficient materials. 

---