Rapid synthesis of self-supported three-dimensional bubble-like graphene frameworks as high-performance electrodes for supercapacitors

Abstract

As one of the most desired alternatives for supercapacitor electrodes, three-dimensional graphene-based materials have attracted massive attention. However, they are still far from meeting the requirements for feasible and promising applications due to their low accessible surface area, poor electrical conductivity, unavailable interconnected self-supported frameworks, and complicated fabrication process. Herein, we originally and rapidly fabricated self-supported three-dimensional bubble-like graphene frameworks via the simpler and greener photopolymerization, which can be completed in a few seconds. The obtained graphene frameworks feature interconnected bubble networks composed of few-layered graphitic membranes, which are spatially and mutually supported. Besides, the simultaneously achieved huge available surface area, excellent conductivity, and superior wettability of the graphene frameworks can ensure sufficient active sites and promote efficient ion transportation, which can synergistically result in superior electrochemical performance when used as an electrode for supercapacitors. The resultant graphene-based supercapacitors exhibit a high gravimetric capacitance of 277 F g⁻¹ at 1 A g⁻¹, a remarkable rate-capability maintained at a level of 85% even at 50 A g⁻¹ and superior cycling stability with 94% capacitance retention and ∼100% coulombic efficiency after 10 000 cycles at 5 A g⁻¹. A soft package symmetrical supercapacitor is also successfully assembled to power light-emitting diodes to demonstrate the promising application of the graphene frameworks. Therefore, the self-supported graphene bubble-networks overcome the defects of currently available graphene products and open avenues for fabricating high-performance, low-cost, high-quality graphene-based electrodes useful for supercapacitors.