3D printing method based on direct ink writing (DIW) opens a novel idea for the structural design of micro supercapacitor electrode with excellent hole structure. However, at present, how to select and broaden the kinds of active materials suitable for printing is still the focus of attention. In this study, two-dimensional lamellar graphene oxide (GO) used as the binder and nano-rod KCu₇S₄ with excellent tunnel shuttle conductivity are used as the raw material to prepare ink suitable for 3D printing through the simple mechanical mixing. After DIW printing, the conductivity of electrode is realized after simple one-step reduction. Printed rGO/KCu₇S₄ electrode shows 815.83 F/g for gravimetric capacitance at 0.5 A/g, corresponding to 7.33 F/cm², and 27.7 F/cm³ for the areal and volumetric capacitance, respectively. At a power density of 2.16 mW/cm², the assembled symmetrical supercapacitor obtains the areal energy density of 286 μWh/cm² and excellent cycle stability. This study reveals a simple, economical, and feasible method for the application of metal sulfide materials for DIW printing of supercapacitors and other electrochemical devices.

Graphical abstract

Reduced graphene oxide and KCu7S4 are printed to fabricate electrodes for high performance supercapacitors.

中文翻译：

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用于高性能超级电容器的直接油墨印刷还原氧化石墨烯/KCu7S4电极

基于直接墨水书写（DIW）的3D打印方法为具有优异孔结构的微型超级电容器电极的结构设计开辟了新思路。然而，目前如何选择和拓宽适合印刷的活性材料种类仍是人们关注的焦点。本研究以二维层状氧化石墨烯（GO）为粘合剂，以具有优异隧道穿梭电导率的纳米棒KCu ₇ S ₄为原料，通过简单的机械混合制备适用于3D打印的油墨。DIW印刷后，经过简单的一步还原，即可实现电极的导电性。印刷 rGO/KCu ₇ S ₄电极显示 0.5 A/g 的重量电容为 815.83 F/g，对应于面积电容和体积电容分别为 7.33 F/cm ²和 27.7 F/cm ^{3 。}在2.16 mW/cm ²的功率密度下，组装的对称超级电容器获得了286 μWh/cm ²的面能量密度和优异的循环稳定性。本研究揭示了一种简单、经济、可行的方法，将金属硫化物材料应用于超级电容器和其他电化学装置的 DIW 打印。

图形概要

印刷还原氧化石墨烯和 KCu7S4 以制造用于高性能超级电容器的电极。