Mass-Produced Electrochemically Exfoliated Graphene for Ultrahigh Thermally Conductive Paper Using a Multimetal Electrode System

Abstract

Herein, the development of a cost-effective system is reported for the mass production of electrochemically exfoliated graphene (EEG) using multiple graphite–stainless-steel electrodes (multicells) in a series configuration and its application to heat transfer. Exfoliation using series-configured multicells leads to the production of high-quality graphene (a few layers of graphene sheets with a low oxygen content and a high C/O ratio of 16.2) at a rate of 30 g per half hour (one-batch). Furthermore, EEG paper is fabricated by the vacuum filtration of the EEG dispersion, and further thermal annealing and mechanical-compression processes are used to investigate the effects of heat and pressure on the thermal conductivities of the EEG paper. EEG paper with wide (100–1000 W m −1 K −1 ) and narrow (100–200 W m −1 K −1 ) ranges of thermal conductivity is obtained when thermally annealed and mechanically compressed, respectively, highlighting the high quality of the massively produced and solution processable graphene. This approach provides a cost-effective process for the mass production of graphene, as well offering a feasible route to highly thermally conductive graphene paper for heat-management applications, such as heat-dissipating media in light-emitting-diode displays, and electronic and photonic devices. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim