Carbons heat-treated

There remains the question why activated carbons differ from carbons heat-treated at 1200° with respect to the relative position of the carboxyl groups. Perhaps this difference is based on the structure of the edges of the carbon layers. Hennig (87, 88) found, by observations with single crystals of graphite, that after oxidation with dry oxygen the armchair configuration of the periphery resulted ... 

Figure 10.12 Voltammetry of ascorbic acid at glassy carbon heat-treated at (a) 520°C, (b) 650°C, (c) 750°C. Scan rate = 0.1 V/s. [Adapted from Ref. 41.]...

FIG U RE 12.2 Typical voltage profiles from carbon materials with different heat-treatment temperatures and different structural variations. The profiles were obtained at the second cycle, and (a) and (b) show discharge and charge cycles by using graphitizable carbon heat-treated at 3000°C, graphitizable carbon heat-treated at 2000°C, and nongraphitic carbon obtained at 700°C. (Reprinted from Endo, M., et al., Carbon, 38, 183, 2000. With permission.)... 

FIG. 4 Microtextural particularities of the structure of microporous activated carbons heat-treated at a low temperature (a) and partially graphitized (b) in compliance with the data of Ref. 74. 

Dibenzotetraazaannulen-cobalt(ll) (CoTAA), [15% on carbon], heat-treated in argon at900K,5h... 

Fig. 8.2 Steady-state current-potential curves in 4 N H2SO4 for adsorbed CoTAABr2 on acetylene-black carbon, heat-treated at 500 °C for 30 min in various atmospheres ...

To explain the relationship between the electrical conductivity and the infrared absorption parameters, a model including the semiconducting phase for the structure of carbons heat treated at lower temperatures was proposed using the effective medium theory to simulate conductivity [103] (see Fig. 30). 

Furthermore, the preparation of graphitic carbon materials requires high temperature heat-treatment, which is disadvantageous in production cost. Non-graphitic carbon heat-treated at around 700 °C shows excellent capacities over 1000 mAh/g... 

Figures 2 and 3 illustrate the evolution of the microstructure for the samples comprising 1 wt.% of calcium carbonate heat treated at 700-900 °C. The foams sintered under 850°C present well-dispersed, ovoid shaped, small pores (0.2-0.4 mm in diameter). For higher sintering temperature, due to a lowering of the liquid glass phase viscosity, gas bubbles growth and contacts lead to larger cavities (0.5-3 mm in diameter). As the mechanical and the insulation properties are influenced by the process temperature in opposite directions, a compromise around 800°C has been found.

Cycle life data for (a) TANS9S series and (b) TANllS series of graphitic carbons heat-treated at 900°C and 1100°C respectively, with sulphuric acid treatment denoted by S followed by the duration of the treatment in hours. (Reprinted with permission from Carbon, 43, Y.J. Kim et al.. Effects of sulfuric acid treatment on the microstructure and electrochemical performance of a polyacrylonitrile (PAN)-based carbon anode, 2005,163-169, Copyright 2005, Elsevier.)... 

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