Current Status and Challenges in Printed Batteries: Toward Form Factor-Free, Monolithic Integrated Power Sources

With the advent of the ubiquitous electronics era, high-performance power sources with aesthetic diversity are indispensably needed as a key-enabling technology. Printed batteries have recently emerged as a crispy energy storage system to address this issue. Printed batteries are fabricated through simple, low-cost, and scalable printing processes. Their salient features include various form factors, shape conformability, and monolithic integration with devices of interest. Research directions on printed batteries are currently focused on (i) the design of battery shapes and configurations, (ii) synthesis of battery component inks with tunable rheological properties and electrochemical performances, and (iii) adoption of suitable printing techniques. We describe the current status and challenges of printed batteries, with a particular focus on the form factors, battery component inks, printing techniques, cell performances, and integration with other systems. The development directions and outlook of printed batteries are also discussed along with their potential applications. This Review provides new insight into printed batteries and their opportunity as an efficient and versatile platform technology to enable shape-versatile/monolithic-integrated power sources with functionalities far beyond those of conventional batteries.