Preparation and lithium-storage performance of carbon/silica composite with a unique porous bicontinuous nanostructure

A class of carbon/silica composite with a porous bicontinuous nanostructure is prepared via a simple sol-gel method and then used as anode material for lithium-ion batteries. The reversible specific capacity of the as-prepared composite stays over 560 mAh g−1 after 30 cycles, much higher than that of many other carbon materials including commercial graphite and carbon/silica composites. The good electrochemical performance can be ascribed to the following three factors: (i) continuous silica gel framework stores most of lithium ions; (ii) continuous carbon framework not only restrains the volume change during repeated insertion and extraction of lithium ions, but also represents an excellent conductive skeleton throughout the composite; (iii) nanopores among the carbon/silica bicontinuous framework are helpful to the mass transport and can further buffer the volume change of silica.