The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is the development of a grid-scale battery to enable large-scale energy storage. Such a battery would improve the performance and reliability of existing power infrastructure, and it would ultimately enable storing backup power from intermittent renewable sources, such as wind and solar. US grid storage capacity today is less than 0.01% of daily generation, 95% of which is geographically-limited pumped hydroelectric storage technology that is already installed where possible. The demand for new grid-level energy storage is seen in the growing use of portable lithium ion technology as a stopgap measure, with storage deployments in 2019 nearly doubling compared to 2018. Specifically, this project will enable a new battery with instant response that is inexpensive, has a 20+ year stability, and is non-flammable. This SBIR Phase I project proposes to validate the use of inexpensive and easy-to-manufacture materials in the fabrication of the cell components of a pH-neutral aqueous, organic redox flow battery (RFB). Current commercial RFBs, such as vanadium systems, utilize expensive materials to withstand their corrosive electrolytes and extreme pH levels. This leads to high component and fabrication costs for the electrochemical cell, inhibiting translation of the technology. Using mild chemistry in pH-neutral conditions is likely to enable the use of inexpensive cell materials. This research project will work to ensure that ubiquitous, inexpensive, and easy-to-manufacture fabrication materials do not impact the stability of a novel 20+ year lifetime pH-neutral aqueous organic flow battery. These materials, such as polyethylene, polypropylene, polyvinyl chloride and other common rubbers and plastics, will be systematically exposed to both the charged and neutral electrolyte for subsequent analysis by NMR, LC/MS, mass spectrometry, surface characterization, stress tests, and various other techniques to ensure that no degradation of their chemical or physical properties occurs. Additional performance tests will be conducted and a prototype will be developed.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.