Research Progress of Three-dimensional Graphene-based Electrodes Based on 3D Printing

Supercapacitor (SC) is a kind of high⁃performance energy storage devices. It has attracted extensive attention due to the advantages of high power density, fast charge and discharge rate, high safety performance, excellent cycle stability and wide operating temperature range. Such advantages bestow SC to be widely used in the fields of clean energy, electric vehicles, wireless communications, aerospace, military and consumer electronics. Electrode material is one of the key factors that determine the energy storage performance of SC. Thus, it is a research hotspot to develop novel and high⁃efficiency electrode material. Conventional electrode materials have achieved some technological innovation and breakthroughs with unremitting efforts, while the disadvantages such as low capacity of carbonaceous electrodes, low conductivity of transition metal compounds and insufficient cycling stability of conductive polymers still limit their further development. Graphene is a kind of carbon⁃based nanomaterial, which composed of a single layer of carbon atom. It has become the new favorite of SC electrode material originated from its excellent physical and chemical properties. Three⁃dimensional graphene (3DG) not only retains the unique physical and chemical properties of the single⁃layer or few⁃layer graphene, but also has the characteristics of low density, porosity, highly connected structure and microscale reaction environment, which endows it with a wider application prospect than graphene, and attracts more attention in the field of SC. At present, wet chemical technology, CVD technology and 3D printing technology are proposed for the preparation of 3DG. Among them, the 3D printing technology has been developed rapidly in the fields of biomedicine and energy devices due to the unique advantages in design of space configuration and optimization of chemical composition. Graphene⁃based materials manufactured by 3D printing not only have good pore distribution as well as excellent mechanical properties, but their unique structure derived from 3D printing also endows the electrodes with new functions and characteristics. Therefore, they play an important role in the development of microelectronic devices towards miniaturization and flexibility. This article reviews the charge storage mechanism and classification of SC electrode materials, and introduces the research progress of 3D printed graphene and its composite system in the application of electrode materials in detail. Moreover, the main problems and challenges encountered by current 3D printed graphene⁃based electrodes were also discussed. It provided new ideas for design, development and application of 3D printed graphene⁃based electrodes. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.