The project will introduce fundamental advances in the theoretical understanding, modeling, simulation, experimental characterization, and development of Li-air flow systems for grid storage, while enhancing the efforts of Florida State University on research and education in energy. Renewable sources produce electric power that is constantly fluctuating in time, sometimes by more than one order of magnitude within a few minutes or hours. At penetrations larger than 20%, these fluctuations require high capacity energy storage devices that are environmentally friendly, reliable, and do not compromise the security of our national grid. The goal of this project is to develop innovative Li-air systems that be scaled-up and used in grid applications. The energy and power ratings of the proposed systems are independently adjustable, making the proposed batteries attractive for building high-capacity and low-cost energy storage devices. In the long term, the project is also expected to impact the current technology for energy storage in electric vehicles and low power electronic devices.