Three-dimensional (3D) printing is gaining importance as a sustainable route for the fabrication of high-performance energy storage devices. It enables the streamlined manufacture of devices with programmable geometry at different length scales down to micron-sized dimensions. Miniaturized energy storage devices are fundamental components for on-chip technologies to enable energy autonomy. In this work, we demonstrate 3D printed microsupercapacitor electrodes from aqueous inks of pristine graphene without the need of high temperature processing and functional additives. With an intrinsic electrical conductivity of ∼1370 S m^–1 and rationally designed architectures, the symmetric microsupercapacitors exhibit an exceptional areal capacitance of 1.57 F cm^–2 at 2 mA cm^–2 which is retained over 72% after repeated voltage holding tests. The areal power density (0.968 mW cm^–2) and areal energy density (51.2 μWh cm^–2) outperform the ones of previously reported carbon-based supercapacitors which have been either 3D or inkjet printed. Moreover, a current collector-free interdigitated microsupercapacitor combined with a gel electrolyte provides electrochemical performance approaching the one of devices with liquid-like ion transport properties. Our studies provide a sustainable and low-cost approach to fabricate efficient energy storage devices with programmable geometry.

中文翻译：

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用于具有高电容的 3D 打印微型超级电容器的原始石墨烯水性油墨

三维 (3D) 打印作为制造高性能储能设备的可持续途径越来越重要。它可以简化制造具有不同长度尺度的可编程几何形状的设备，直至微米尺寸。小型化储能设备是实现能源自主的片上技术的基本组件。在这项工作中，我们展示了从原始石墨烯的水性墨水中 3D 打印的微型超级电容器电极，而无需高温处理和功能添加剂。凭借~1370 S m ^–1的本征电导率和合理设计的架构，对称微型超级电容器在 2 mA cm ^{–2 下}表现出 1.57 F cm ^–2的特殊面电容经过反复电压保持测试后，仍保持在72%以上。面功率密度 (0.968 mW cm ^–2 ) 和面能量密度 (51.2 μWh cm ^–2 ) 优于先前报道的 3D 或喷墨打印的碳基超级电容器。此外，无集电器的叉指微超级电容器与凝胶电解质相结合，提供了接近具有液体离子传输特性的器件之一的电化学性能。我们的研究提供了一种可持续且低成本的方法来制造具有可编程几何形状的高效储能设备。