Facile fabrication and electrochemical oxidation of activated carbon microtube bundles for advanced all-solid-state supercapacitor.

The energy density of carbon microtube bundles is usually low and the preparation process is also complex. By carbonization, washing and activation, the prepared metaplexis shell-based carbon microtube bundles has not only an open structure, but also a rich porous structure on the tube wall. The pulsed electrooxidation technology can promote the formation of functional groups on the tube wall and further enhance the energy density of the material. After assembling the electrooxidized material into an all-solid-state supercapacitor, the capacitor has a capacity of 15.1 Wh kg-1 at 0.5A g-1 and a capacity retention rate of 95.9% after 10000 cycles at 10 A g-1, indicating that these functional groups are relatively stable. The results show that the metaplexis shell-based carbon microtube bundles before pulsed electrooxidation is more suitable as a positive electrode material, while the electrooxidized material can be either positive or negative electrode material. This work provides an idea for the design and development of the electrode materials in the high-performance all-solid-state supercapacitor.