Electrochemically Exfoliated Graphene Additive-Free Inks for 3D Printing Customizable Monolithic Integrated Micro-Supercapacitors on a Large Scale.

Zhang, Longlong; Qin, Jieqiong; Das, Pratteek; Wang, Sen; Bai, Tiesheng; Zhou, Feng; Wu, Mingbo; Wu, Zhong-Shuai · Adv Mater · 2024

basic_science · Level V

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Abstract

Three-dimensional (3D) printing technology with enhanced fidelity can achieve multiple functionalities and boost electrochemical performance of customizable planar micro-supercapacitors (MSCs), however, precise structural control of additive-free graphene-based macro-assembly electrode for monolithic integrated MSCs (MIMSCs) remains challenging. Here, the large-scale 3D printing fabrication of customizable planar MIMSCs is reported utilizing additive-free, high-quality electrochemically exfoliated graphene inks, which is not required the conventional cryogenic assistance during the printing process and any post-processing reduction. The resulting MSCs reveal an extremely small engineering footprint of 0.025 cm<sup>2</sup>, exceptionally high areal capacitance of 4900 mF cm<sup>-2</sup>, volumetric capacitance of 195.6 F cm<sup>-3</sup>, areal energy density of 2.1 mWh cm<sup>-2</sup>, and unprecedented volumetric energy density of 23 mWh cm<sup>-3</sup> for a single cell, surpassing most previously reported 3D printed MSCs. The 3D printed MIMSC pack is further demonstrated, with the maximum areal cell count density of 16 cell cm<sup>-2</sup>, the highest output voltage of 192.5 V and the largest output voltage per unit area of 56 V cm<sup>-2</sup> up to date are achieved. This work presents an innovative solution for processing high-performance additive-free graphene ink and realizing the large-scale production of 3D printed MIMSCs for planar energy storage.