New hierarchical hollow SiO2 spheres (HHSs) decorated with metal nanoparticles (i.e., Co, Co–HHS) were designed using an in situ self-assembly approach. The Co nanoparticles were found to have a catalytic effect on (de-)lithiation of SiO2 and hence in storing lithium. Then, an extremely high capacity of 932 mA h g−1 and good cycling stability for more than 1000 cycles were demonstrated in the corresponding lithium battery. In addition, the lithium-ion full batteries of the Co–HHS versus lithium layered oxide cathode (e.g., LiNi1/3Co1/3Mn1/3O2, NCM333) were introduced and showed good performance, demonstrating the promising application of the Co–HHS, in particular for pursuing high-energy-density batteries.