Correlation of synthesis parameters and physicochemical properties of biomass-derived carbon-titania composites

Abstract

The synthesis of an efficient lithium battery anode requires active and conductive materials. Composites are often used, but their preparation requires numerous parameters and attempts to maximize the crystalline phase or texture. To limit the number of syntheses, factor analysis is a useful tool for determining the critical parameters. This method has been applied to titania-based anodes. Biomass-derived carbon-titania composites were prepared through sol–gel synthesis followed by drying and pyrolysis under a nitrogen gas flow. Four synthesis parameters were investigated: the presence of kapok-based carbon fiber, the acid used as the sol–gel catalyst, the drying process, and the pyrolysis temperature. Owing to the Yates formula, the optimal conditions leading to an optimized specific surface area (SSA) enhancing lithium-ion diffusion are highlighted. Conclusively, whereas kapok-based carbon and supercritical drying are essential for achieving high SSAs, the effect of pyrolysis temperature on TiO₂ crystallinity depends on the acid-based sol–gel conditions, and to favor anatase instead of rutile, acetic acid should be used. As a result, this method of synthesis and implementation has made it possible to use the most suitable samples without extra conductive carbon as anodes in lithium-ion batteries and their electrochemical characteristics have been obtained using galvanostatic measurements over 40 cycles.

Graphical abstract