Rapid Fabrication of Porous Graphene Network Derived Using Photothermal Flash Lamp Processing for High Performance Electrochemical Energy Storage Devices

Abstract

Graphene offers superior electrical conductivity and remarkable surface area, which holds great promise for electrochemical energy storage applications including supercapacitors and lithium-ion batteries. Current preparation methods for graphene-like materials require relatively long processing times, extremely high temperatures within controlled atmospheres, and/or involve multi-step reactions that present challenges for high throughput fabrication of graphene-based devices. Moreover, supercapacitor devices fabricated using graphene typically exhibit low areal capacitance, which limits use of the devices. We report a photothermal route to large-scale production of graphene within milliseconds from polymers using high intensity xenon flash lamp on carbon fiber at ambient conditions. The xenon flash lamp provides large-area illumination and a wide emission band (300 nm –1100 nm) that was used to convert the polymeric material directly into graphene upon millisecond exposures. This photothermally heating of polymeric material led to the formation of macroporous few layer graphene-containing network with excellent conductivity, and good adhesion to the carbon fiber all of which facilitate the transport of ions through the material. The fabricated supercapacitor devices exhibited a very high areal capacitance of 200 mF/cm2 at 10 mV/s with retention of more than 70% of its capacitance even after increasing the scan rate to 100 mV/s. Anodes for lithium-ion batteries derived from porous graphene networks on carbon fiber resulted in the device with the performance of 170 mAh/g with mass loading as high as 12 mg/cm2 (including the mass of bare CF). The preparation of high-quality graphene via photothermal pyrolysis of polyaniline is amenable to high throughput processing, enabling large-scale production of electrochemical energy storage devices.