3D Printing of Tunable Energy Storage Devices with Both High Areal and Volumetric Energy Densities

Abstract

materials play a determined role in offering high performance for supercapacitors. There are usually two ways to enhance the electrochemical performance of supercapacitors. One is exploring new electrode materials with high surface area and conductivity, such as advanced carbonbased materials, and the other one is constructing reasonable electrode structure with unimpeded electron and ion pathways. [4][5][6][7][8] To date, many efforts have been dedicated to developing a variety of carbonaceous materials with different morphologies, such as CNT, AC, graphene, carbon nanofibers, whereas less attention has been focused on the optimization of carbon-based electrode structures. [9][10][11][12][13] How to properly design and regulate the electrode microstructures (electrode architecture engineering) based on the existed materials using advanced fabrication and assembly methods to further optimize the performance is also of great significance.A few fabrication and assembly methods, such as vacuum filtration, [14] freeze-casting, [15] solvothermal gelation, [16] and chemical vapor deposition (CVD), [17] have been proposed to adjust the carbon-based electrode architectures. However, for the CVD method, it is expensive and not scalable, and the obtained electrode structures are generally fragile. The electrode architecture prepared by the vacuum filtration, freeze-casting and solvothermal gelation is largely stochastic and highly tortuous, which greatly hinders electrolyte ion transport. Thus, the controllable and scalable electrode fabrication with tailored architectures remains a great challenge. [18] The extrusion-based Developing advanced supercapacitors with both high areal and volumetric energy densities remains challenging. In this work, self-supported, compact carbon composite electrodes are designed with tunable thickness using 3D printing technology for high-energy-density supercapacitors. The 3D carbon composite electrodes are composed of the closely stacked and aligned active carbon/carbon nanotube/reduced graphene oxide (AC/CNT/rGO) composite filaments. The AC microparticles are uniformly embedded in the wrinkled CNT/rGO conductive networks without using polymer binders, which contributes to the formation of abundant open and hierarchical pores. The 3D-printed ultrathick AC/CNT/rGO composite electrode (ten layers) features high areal and volumetric mass loadings of 56.9 mg cm −2 and 256.3 mg cm −3 , respectively. The symmetric cell assembled with the 3D-printed thin GO separator and ultrathick AC/CNT/rGO electrodes can possess both high areal and volumetric capacitances of 4.56 F cm −2 and 10.28 F cm −3 , respectively. Correspondingly, the assembled ultrathick and compact symmetric cell achieves high areal and volumetric energy densities of 0.63 mWh cm −2 and 1.43 mWh cm −3 , respectively. The all-component extrusion-based 3D printing offers a promising strategy for the fabrication of multiscale and multidimensional structures of various high-energy-density electrochemical energy storage devices. 3D-Printed S...

Compact Assembly and Programmable Integration of Supercapacitors

“…As revealed by the Nyquist plot, the CmSC shows a low equivalent series resistance of only 13.8 Ω, indicating fast ion diffusion at the interface of electrode materials and electrolyte. The volume‐specific capacitance is calculated as 47 F cm −3 at a current density of 50 mA cm −3 , which is better than that of other carbon‐based mSCs with gel electrolyte reported previously (Figure d) . The huge volume‐specific surface area and good contact interface between electrode materials and electrolyte, electrode materials and current collector contributed to the outstanding electrochemical performance of CmSC together.…”

“…A computer‐controlled laser engraving system was utilized to prepare the slices of rGO hydrogel block (Figure S1c, Supporting Information) and GO slurry was sandwiched between two rGO slices as separator and binder, together with inserted conductive wires (e.g., gold wires) as current collectors ( Figure a). Thereinto, some adhesion‐related applications have been demonstrated to use GO as glue . This kind of property is mainly related to the proper sheets size (several µm), abundant surface, and edge‐sited oxygenated groups on GO sheets.…”

3D Printing of Ultralight Biomimetic Hierarchical Graphene Materials with Exceptional Stiffness and Resilience

“…On the basis of these demands, several 3D printing methods, including isooctane supported printing, cold sink assisted printing, and directly printing in air environment,12e,18 have been demonstrated for printing graphene aerogel materials. Compared with the conventional bulk graphene aerogels, 3D‐printed graphene materials demonstrated unique properties, such as rapid ions and electrons transportation, which are beneficial for electrochemical performance . Importantly, functional dopants can be easily incorporated into the 3D‐printed graphene materials, which demonstrates a potential of producing multifunctional graphene‐based composites to meet the requirements of diverse applications, such as the high‐performance electrodes for energy‐related applications 12e,18,20.…”

Biomimetic and Radially Symmetric Graphene Aerogel for Flexible Electronics

“…Raman spectra were further used to characterize the chemical reduction and structural information of the rGO. [6,40] The high I D /I G value indicates the high graphitization degree to favorably enhances the conductivity of the rGO, [41] which would play an imperative role in flexible electronics. [6,40] The high I D /I G value indicates the high graphitization degree to favorably enhances the conductivity of the rGO, [41] which would play an imperative role in flexible electronics.…”