Hypercrosslinking-induced self-assembled carbon nanospheres: a synergistic system integrating hollow structures, micro–mesopores, and nitrogen doping for supercapacitors

Abstract

Polylactide-b-polystyrene (PLA-b-PS) was used as the precursor to prepare hollow microporous organic nanospheres (H-MONSs) via hypercrosslinking self-assembly. Subsequently, nitrogen was introduced into H-MONSs through the hypercrosslinking reaction between aniline and PLA-b-PS, and finally nitrogen-doped hollow porous carbon nanospheres (N-HPCNSs) were obtained by further pyrolysis. Experimental results revealed that the molar ratio of aniline to benzene groups from PLA-b-PS and the carbonization conditions have crucial impacts on the sample's morphology, porous structure and corresponding electrochemical performance. Benefiting from the synergistic effect of the hollow structure design, micro–mesoporous architecture construction, and nitrogen doping modification, PLA₁₅₀-PS₂₅₀-N₄-900-10H, which has a nitrogen content of 3.57% and a surface area of up to 945 m² g⁻¹, exhibits the best capacitance of 250 F g⁻¹ at a current density of 1.0 A g⁻¹. Furthermore, ∼98% of the capacitance of N-HPCNSs is retained after 1500 cycles at a current density of 25 A g⁻¹. The above results enable the construction of an excellent electrochemical platform featuring “high accessible specific surface area, short diffusion path and continuous electron/ion dual transport”.