Carbon Monoliths with Hierarchical Porous Structure for All-Vanadium Redox Flow Batteries

Carbon monoliths were tested as electrodes for vanadium redox batteries. The materials synthesised by a hard-templating route, employing sucrose carbon precursor and sodium chloride crystals the hard template. For preparation process, both ball-milled together molten into paste which was hot-pressed to achieve polycondensation of monolith. resultant material pyrolysed in nitrogen at 750 °C, then washed remove salt dissolving it water. Once porosity opened, second pyrolysis step 900 °C performed complete conversion carbon. products next characterised terms textural properties composition. Changes porosity, obtained varying proportions initial mixture, correlated with electrochemical performances samples, good agreement between capacitive response microporosity indeed observed highlighted an increase cyclic voltammetry curve area when SBET increased. In contrast, reversibility reactions measured function difference reduction oxidation potentials accessibility active species surface, i.e., macroporosity. latter critical parameter understanding differences energy voltage efficiencies among materials, those larger macropore volumes having higher efficiencies.