Customizable Supercapacitors via 3D Printed Gel Electrolyte

Abstract New manufacturing strategies toward customizable energy storage devices (ESDs) are urgently required to allow structural designability for space and weight‐sensitive electronics. Besides the macroscopic geometry customization, the ability to fine‐tune the ESD internal architectures are key to device optimization, allowing short and uniform electrons/ions diffusion pathways and increased contact areas while overcoming the issues of long transport distance and high interfacial resistance in conventional devices with planar thick electrodes. ESDs with 2D or 3D electrodes filled with liquid or gel‐like electrolyte have been reported, yet they face significant challenges in design flexibility for 3D ESD architectures. Herein, a novel method of assembling ESDs with the ability to customizing both external and internal architectures via digital light processing (DLP) technique and a facile sequential dip‐coating process is demonstrated. Using supercapacitors as prototype device, the 3D printing of ESDs with areal capacity of 282.7 mF cm −2 which is higher than a reference device with same mass loading employing planar stacked configuration (205.5 mF cm −2 ) is demonstrated. The printed devices with highly customizable external geometry conveniently allow the ESDs to serve as structural components for various electronics such as watchband and biomimetic electronics which are difficult to be manufactured with previously reported strategies.