STTR Phase I: Organic Additives to Improve Performance in Zinc-Air Batteries

This STTR Phase I project will remove the most critical roadblock to making long-lasting batteries from safe and economical zinc and air. Zinc is plentiful in the U.S. and zinc-air batteries have the potential to hold more than five times the energy of current lithium-ion batteries, but a key challenge for making rechargeable zinc-air batteries is that the zinc inside the battery naturally forms sharp needles called dendrites during recharging. Over time these dendrites can grow large enough to damage the inner workings of the battery, reducing efficiency and lifetime. This project will borrow principles from an adjacent field, the electroplating industry, to create new organic chemicals that will seek out and stop dendrite growth within the battery during recharging. Chemical additives have a long history in electroplating for controlling the shape of metal surfaces, and the same principles can apply to additives designed here to control zinc growth during battery recharging. This new technology will make zinc-air batteries cheaper and longer-lasting to eventually replace existing battery technologies, enabling longer-distance electric vehicles, reducing equipment weight for soldiers, contributing a valuable technology to the economy, and helping to maintain the role of the U.S. as a leader in energy storage technology. This STTR Phase I project will identify the critical chemistry necessary to elegantly and economically suppress zinc dendrite formation, alleviating one of the most significant challenges complicating the full commercial emergence of Zn-Air battery technology. Eschewing the established tactic of applying existing chemicals from the catalog, this project will take inspiration from the PI?s experience designing additives for similar environments in the electroplating industry to introduce novel proprietary organic chemistry addressing the dendrite bottleneck directly. The key technical challenge will be to optimize the molecular features to simultaneously provide efficient dendrite suppression and low voltage loss. A broad series of molecules will be created to combine strong interactions with zinc, modest polarization, low cost and straightforward scalability. Evaluating and iterating upon these candidates in bench-scale electrochemical analyses and performance tests in coin and pouch cell batteries will yield a dendrite-suppressing product to bring significant value to Zn-Air technology and other Zn-based battery markets. At its successful conclusion, this project will not only produce products for these markets, but it will also provide molecular design principles useful for the development of other metal-based battery additives, and promote the merits of novel additive development for the broader battery industry.