Next-Generation Rechargeable Zn Batteries for Electric Vertical Takeoff and Landing (eVTOL) Aircraft

Rechargeable batteries with high specific energy and power, long cycle life, and high safety are needed to enable the emerging Electric Vertical Takeoff and Landing/Urban Air Mobility (eVTOL/UAM) market for potential disaster response, humanitarian aid, and logistics missions. Rechargeable zinc-air batteries (ZABs) are listed as a promising candidate in the battery market, owing to their advantages in terms of environmental friendliness, abundance of the constituent elements, and safe operation. Especially Zn is highlighted as a high-capacity, sustainable, cost-efficient, and recyclable material. ZABs may achieve gravimetric and volumetric energy densities of 500 Wh/kgcell and 1400 Wh/Lcell (based on the practical attainable values of commercially available primary ZABs in coin cell format), which is by good approximation twice as much as today’s commercialized Li-ion batteries (350 Wh/kgcell and 810 Wh/Lcell). Rechargeable ZABs are, however, not yet realized in practice despite 50 years of intensive research because of two major degradation phenomena: (i) the fast degradation of the cathode materials such as catalyst, binder, or carbon additive and (ii) the morphological changes of the Zn anode during repeated cycling, leading to an irreversible deformation of the entire anode. Lynntech proposes to develop next-generation high performance and cost-effective rechargeable ZABs based on the combination of an advanced rechargeable Zn anode developed by Georgia Institute of Technology (Georgia Tech.), and a bifunctional holey graphene-based cathode developed by Lynntech, as well as a salt-in-water electrolyte. During the Phase I, Lynntech, in collaboration with Georgia Tech., will fabricate and test lab-scale next-generation ZAB cells. During the Phase II, Lynntech will work with Georgia Tech. and a battery manufacturer to further improve the electrodes and electrolytes as well as battery design. We will fabricate and demonstrate prototype rechargeable ZABs. High energy, high power, and long cycle life ZABs have tremendous market opportunities for both Air Force/DoD and commercial applications.