Microphase Separation Engineering toward 3D Porous Carbon Assembled from Nanosheets for Flexible All-Solid-State Supercapacitors

Although hierarchitectures could energize carbon materials to address the challenges encountered in emerging flexible energy storage, how to make the trade-offs among specific surface area, pore configuration, and conductivity is still a lingering issue. Herein, 3D porous carbon assembled by nanosheets (HCAs) with tunable hierarchical porous structure is acquired from amphiphilic coal tar pitch and chitosan by means of a facile microphase separation strategy without any templates. The polar molecular chains of chitosan and the surrounding pitch molecules with strong pi-pi* bonds self-assemble respectively to form hierarchical pores and a network of nanosheets in a stepped pyrolysis process. Due to the combined effects of the mesodominant porous structure, high specific surface area, and nitrogen-rich nature, the as-assembled symmetric all-solid-state supercapacitor with a wide voltage range of 0-1.8 V delivers a specific capacitance of 296 F g(-1) at 0.2 A g(-1) and an energy density of 27 Wh kg(-1) at a power density of 450 W kg(-1). The strategy of microphase separation is proposed originally to design and to fabricate carbon materials with multilevel nanoarchitectural trade-offs for high-performance supercapacitors.

Automated summary

In this study, a template-free microphase separation strategy was proposed to fabricate 3D porous carbon materials with tunable hierarchical structure for high-performance supercapacitors. The self-assembly of chitosan and coal tar pitch resulted in the formation of hierarchical pores and a network of nanosheets. The assembled supercapacitor exhibited advantages of wide voltage range, high specific capacitance, and energy density.