Additively manufactured electrodes for supercapacitors: A review

Abstract Three-dimensional (3D) printing, a form of additive manufacturing (AM), has been adapted across industries to manufacture customized structures using multiple materials. This has been of special advantage in applications where conventional manufacturing techniques limit the potential of the products either due to the inability to impart complex geometries or utilize different materials in their production. Energy storage devices, such as electrochemical capacitors attract increasing interest for applications in disparate fields ranging from automobiles to heath care. As such, the need of the hour is to develop low-cost, long-lasting, and environmentally friendly devices. The development of 3D printed electrodes for supercapacitors is increasingly being seen as a more viable alternative to conventionally manufactured ones. Different structures and forms of electrodes can be produced with 3D printing, all of which contribute to optimizing the performance of the supercapacitor. A comprehensive review that unifies the current research on 3D printed supercapacitors will help researchers establish a baseline on which to base future studies. This review focuses on the current state of both ECs and AM techniques and takes a critical look at the fabrication processes and materials used for 3D printed electrodes. An in-depth analysis of associations between the electrochemical properties of the device and the methods and materials used is provided. Following that, recommendations are made regarding possible research directions to overcome the existing shortcomings of 3D printed supercapacitors.