An interfacial self-assembly strategy to fabricate graphitic hollow porous carbon spheres for supercapacitor electrodes

Graphitic hollow porous carbon spheres (GHPCSs) have the advantages of a unique cavity structure, high surface area and excellent conductivity, and are promising electrode materials for energy storage. A Fe-tannic acid (TA) framework synthesized using TA as the carbon source and K-3[Fe(C2O4)(3)] as a complexing agent, was self-assembled onto a melamine foam, which was converted to GHPCSs by carbonization, where the K-3[Fe(C2O4)(3)] also acts as an activating-graphitizing agent. The outer shell of the as-prepared GHPCSs has a large specific surface area, a micropore-dominated structure and excellent electrical conductivity, which ensure a large enough active surface area for charge accumulation and fast ion/electron transport in the partially graphitized carbon framework and pores. The optimum GHPCS has a high capacitance of 332.7 F g(-1) at 1 A g(-1) . An assembled symmetric supercapacitor has a high energy density of 23.7 Wh kg(-1) at 459.1 W kg(-1) in 1 mol L-1 Na2SO4. In addition, the device has long-term cycling stability with a 92.1% retention rate after 10,000 cycles. This study not only provides an economic and time-saving approach for constructing GHPCSs by a self-assembly method, but also optimizes ion/electron transport in the carbon spheres to give them excellent performance in capacitive energy storage.

Automated summary

The translation introduces the advantages, preparation method, and performance of graphitic hollow porous carbon spheres. The study successfully constructs graphitic hollow porous carbon spheres using an economic, time-saving self-assembly method and optimizes ion/electron transport in the carbon spheres, resulting in excellent performance in capacitive energy storage.