All-Hand-Drawn Zn-Air Batteries: Toward User-Customized On-the-Fly Power Sources

The upcoming ubiquitous era, which will foresee the widespread popularity of Internet of Things (IoT) and wearable electronics, is in urgent need of high-performance/flexible power sources with various form factors. Here, a new class of user-customized, on-the-fly power source based on an all-hand-drawn primary zinc (Zn)-air battery system is demonstrated. The all-hand-drawn Zn-air batteries are fabricated directly on A4 paper (serving as a mechanical substrate and gas diffusion layer) under ambient conditions by using a simple pen/pencil-based hand drawing technique. The Zn-air batteries consist of pen-drawn silver current collectors, pen-drawn Zn anodes, pencil-drawn carbon air cathodes, and pen-drawn gel electrolytes. Notably, oil painting-inspired Zn anode ink presents well-tailored rheological properties for the pen drawing. Subsequent UV curing enables the pen-drawn Zn anode to show dimensional stability and long-term structural integrity. The resulting Zn-air batteries exhibit reliable electrochemical performance and on-demand control of cell voltage/capacity. The all-hand-drawn Zn-air batteries are aesthetically unitized with various IoT devices including an e-sketch of a light bulb and a smart paper lampshade as an unprecedented on-the-fly power source, underscoring the exceptional process simplicity, ubiquitous portability and design versatility that lie far beyond those achievable with conventional battery technologies.