Understanding the effect of the mesopore volume of ordered mesoporous carbons on their electrochemical behavior as Li-ion battery anodes

This work aims at understanding the effect of the mesopore volume of ordered mesoporous carbons (OMCs) on their behavior as anodes for Li-ion batteries. To that purpose, the hard-templating method was used as an enabling tool, with the controlled partial etching of the silica template to prepare a series of OMCs with a wide range of mesopore volumes. The formed carbon-silica hybrids were processed into electrodes using a water-based ink preparation route in the presence of xanthan gum as a binder, which retained access to the pores after formation of the electrodes. The pore texture of the latter was compared to that of the starting powders. A very good linear relationship could be evidenced between the mesopore volume of the electrodes and the first insertion capacity of Li-ions. The lithium de-insertion also followed a linear trend, but its behavior was dependent on the final applied potential. Indeed, the higher the mesopore volume, the higher the contribution of de-insertion at elevated voltages. This study further points out the importance of the textural characterization of electrodes (instead of just the starting material) as well as the conditions at which the electrochemical measurements are carried out, especially the maximum applied de-insertion voltage.Promotee, Batwa