High capacitive storage behavior of hierarchically porous hollow‑carbon spheres derived from the coupling of template-directing and post-activation methodology

The hierarchically porous hollow‑carbon spheres (HPHCSs) are synthesized by activating the hollow‑carbon spheres (HCSs) derived from the template-directing method using SiO 2 spheres and waste tire pyrolysis oil (WTPO) as templates and carbon precursor, respectively. The developed template-directing coupled with post-activation methodology can not only adjust the pore structure of HPHCSs, but also can not destroy the hollow-sphere-like micromorphology. HPHCSs with a relative-intact hollow sphere microarchitecture and abundant micro-mesoporous structure possess the outstanding hydrophilcity and electrical conductivity. As the capacitive energy-storage electrode, HPHCSs electrode presents excellent rate capability, high capacitance retention and good durability in aqueous and organic electrolytes, exhibiting a good compatibility to different kind of electrolyte ions. Besides, the increased ratio of IR drop of HPHCSs electrode is relatively small among the contrast samples possessing different pore structures with the decrease of the test temperature, exhibiting its exceptional low-temperature performance. The favorable combination of template-directing and post-activation is able to realize the controllability of the pore structure of HPHCSs electrode with high capacitive storage behavior. Furthermore, this work also provides a valuable strategy for the preparation of electrode materials with high capacitive energy-storage ability through the high value-added utilization of WTPO. • HPHCSs are synthesized by the coupling of template-directing and post-activation methodology. • HPHCSs electrode possesses the outstanding compatibility to different electrolyte systems. • The superior capacitive behavior of HPHCSs is mainly benefited from the micro-mesoporous structure. • The high value-added utilization of WTPO is realized by the construction of the capacitive electrode material.