Electric batteries, Vol. 7, Pages fifty five: Carbon Monoliths with Hierarchical Porous Structure for All-Vanadium Redox Flow Batteries
Batteries doi: 10. 3390/batteries7030055
Writers: Jose Francisco Vivo-Vilches Blagoj Karakashov Alain Celzard Vanessa Fierro Ranine El Hage Nicolas Brosse Anthony Dufour Mathieu Etienne
Co2 monoliths were tested since electrodes for vanadium redox batteries. The materials were synthesised by a hard-templating route, employing sucrose because carbon precursor and salt chloride crystals as the hard template. For the particular preparation process, both sucrose and sodium chloride had been ball-milled together and molten into a paste that was hot-pressed to achieve polycondensation of sucrose into a hard monolith. The resulting material was pyrolysed in nitrogen at 750 °C, and then washed to remove the salt by dissolving it in drinking water. Once the porosity had been opened, a second pyrolysis step at 900 °C was performed for the particular complete conversion from the materials into carbon. The items were next characterised in terms of textural attributes and composition. Changes in porosity, obtained by varying the proportions of sucrose to sodium chloride in the initial mixture, had been correlated with the electrochemical performances of the sample, along with a good agreement between capacitive response and microporosity was indeed observed featured by an increase in the cyclic voltammetry competition area when the SBET increased. In contrast, the reversibility of vanadium redox reactions measured as a function of the difference in between reduction and oxidation possibilities was correlated with the accessibility of the active v (symbol) species to the co2 surface, i. e., was correlated with the macroporosity. These was a critical unbekannte for understanding the distinctions of energy and voltage efficiencies among the materials, those with larger macropore volumes having the increased efficiencies.
