Hierarchically Designed Electron Paths in 3D Printed Energy Storage Devices.

Three-dimensional (3D) microsupercapacitors (MSC) have been spotlighted, because they overcome limited areal capacitance of two-dimensional planar MSCs. Specially, 3D printing technology offers numerous advantages to generate 3D electrodes for MSCs, which includes time-saving, cost-effective manufacturing, and realization of tailorable complex electrode designs. In this paper, we report novel hierarchical 3D designs of conductive 3D electrodes for MSC by digital light processing (DLP)-based 3D printing. Photocurable composite resin with silver nanowires was optimized for DLP printing for the hierarchical design of high aspect ratio in 3D electrodes. The hierarchical 3D electrodes showed unique patterns on the structure corresponding to stacking of layers in the direction of 3D printing. The fabricated 3D MSCs demonstrated low electrical resistance to be used as feasible MSC electrodes. Energy storage from silver redox reactions was demonstrated in hierarchical 3D electrodes designed with mechanically durable 3D octet trusses.