Design of Experiments Electrolyte Evaluation Plan. The goal of this subtask is to perform an extensive Design of Experiments (DOE) to deliver a high- fidelity, high-volume dataset that maximizes the accuracy and efficiency of the data-driven electrolyte downselection process. The first screen will involve up to 100 electrolyte formulations for initial model training with subsequent screens anticipated to consist of 50‒100 formulations resulting in > 250 unique electrolyte formulations being screened during this project. The Recipient shall: • Evaluate the variables listed below for the DOE process. Those identified as providing the greatest return on investment (ROI) will be included in the electrolyte screen. ROI will be determined by weighting existing knowledge about electrolyte properties and impact on cell performance, ease of measurement, and anticipated quality of collected data. o Electrolyte formulation – solvents, salts, additives, and ratios with a fixed cost threshold. Targeting over 250 unique formulations over the course of this project. o Measured or computed electrolyte properties – conductivity, density, freeing point, viscosity, flash point, voltage stability, and water concentration o Membrane identity – Recipient will test between one and three of their leading XXXX membrane designs o Cell format – full Li|NMC cells, symmetric Li|Li cells, asymmetric Li|Cu cells o Data replication – number of cells per formulation and control cells o Formation conditions – temperature, rest time, rest voltage, charge/discharge current density o Cell cycling conditions and data collection – coulombic efficiency, impedance, area specific resistance, cycle life to 80% capacity, and rate performance o Post-mortem analysis – visual inspection of lithium metal anode, surface characterization by X-ray photoelectron spectroscopy, scanning electron microscopy of lithium metal anodes with image analysis such as ImageJ • Create a DOE Electrolyte Test Plan that includes a detailed assessment of each variable listed above, the potential impact on the electrolyte screen, anticipated ROI, key risks, risk mitigation plan, a list of the electrolyte formulations to be tested, and an action plan to execute the data-driven electrolyte optimization. Products: • DOE Electrolyte Test Plan
