Review of Flash Joule Heating for the Synthesis of Graphene and Other Functional Carbon Materials

ABSTRACT Flash Joule heating (FJH), as a high‐efficiency and low‐energy consumption technology for advanced materials synthesis, has shown significant potential in the synthesis of graphene and other functional carbon materials. Based on the Joule effect, the solid carbon sources can be rapidly heated to ultra‐high temperatures (> 3000 K) through instantaneous high‐energy current pulses during FJH, thus driving the rapid rearrangement and graphitization of carbon atoms. This technology demonstrates numerous advantages, such as solvent‐ and catalyst‐free features, high energy conversion efficiency, and a short process cycle. In this review, we have systematically summarized the technology principle and equipment design for FJH, as well as its raw materials selection and pretreatment strategies. The research progress in the FJH synthesis of flash graphene, carbon nanotubes, graphene fibers, and anode hard carbon, as well as its by‐products, is also presented. FJH can precisely optimize the microstructures of carbon materials (e.g., interlayer spacing of turbostratic graphene, defect concentration, and heteroatom doping) by regulating its operation parameters like flash voltage and flash time, thereby enhancing their performances in various applications, such as composite reinforcement, metal‐ion battery electrodes, supercapacitors, and electrocatalysts. However, this technology is still challenged by low process yield, macroscopic material uniformity, and green power supply system construction. More research efforts are also required to promote the transition of FJH from laboratory to industrial‐scale applications, thus providing innovative solutions for advanced carbon materials manufacturing and waste management toward carbon neutrality.