A highly resilient mesoporous siox lithium storage material engineered by oil-water templating

Mesoporous silicon-based materials gained considerable attention as high-capacity lithium-storage materials. However, the practical use is still limited by the complexity and limited number of available synthetic routes. Here, we report carboncoated porous SiO_x as high capacity lithium storage material prepared by using a sol-gel reaction of hydrogen silsesquioxane and oil-water templating. A hydrophobic oil is employed as a pore former inside the SiO_x matrix and a precursor for carbon coating on the SiO_x. The anode exhibits a high capacity of 730 mAhg^-1 and outstanding cycling performance over 100 cycles without significant dimensional changes. Carbon-coated porous SiO_x also showed highly stable thermal reliability comparable to that of graphite. These promising properties come from the mesopores in the SiO_x matrix, which ensures reliable operation of lithium storage in SiO_x. The scalable sol-gel process presented here can open up a new avenue for the versatile preparation of porous SiO_x lithium storage materials.