Inkjet-Printing Technology for Supercapacitor Application: Current State and Perspectives.

Inkjet-printing (IJP) technology is recognized as a significant breakthrough in manufacturing high-performance electrochemical energy storage systems. In comparison to conventional fabrication protocols, this printing technique offers various advantages, such as contact-less high-resolution patterning capability; low-cost, controlled material deposition; process simplicity; and compatibility with a variety of substrates. Due to these outstanding merits, significant research efforts have been devoted to utilizing IJP technology in developing electrochemical energy storage devices, particularly in supercapacitors (SCs). These attempts have focused on fabricating the key components of SCs, including electrode, electrolyte, and current collector, through rational formulation and patterning of functional inks. In an attempt to further expand the material design strategy and accelerate technology development, it is urgent and essential to obtain an in-depth insight into the recent developments of inkjet-printed SCs. Toward this aim, first, a general introduction to the fundamental principles of IJP technology is provided. After that, the latest achievements in IJP of capacitive energy storage devices are systematically summarized and discussed with a particular emphasis on the design of printable functional materials, the printing process, and capacitive performance of inkjet-printed SCs. To close, existing challenges and future research trends for developing state-of-the-art inkjet-printed SCs are proposed.