Current Collector Design of Experiments. The goal of this subtask is to downselect top ten candidate current collectors for initial evaluation in consultation with leading experts from academia and industry that are committed to supporting this project. The Recipient shall: • Evaluate candidate current collectors based on the following criteria: o Potential for smooth lithium nucleation and growth – thermodynamic nucleation overpotential and Li surface diffusion activation energy evaluated with density functional theory computations o Safety – evaluate thermal stability, conductivity, and “fuse-like” potential with Soteria’s current collector to mitigate shorting hazards o Density – factors directly into cell energy density o Mechanical properties – tensile strength and modulus related to thickness o Availability – is it already commercial or does it need to be produced? o Sustainability – is it composed of low-impact and recyclable materials? o Manufacturability – ease of manufacturing and anticipated cost o Tab bonding – compatibility with standard ultrasonic tab welding for current extraction o Reduction and alloying potential – impact of lithium plating on the fundamental chemistry of the material • Develop current collector testing protocol applying DOE methodology and produce a Current Collector Testing Plan that outlines initial downselect of candidate materials and how current collectors will be evaluated by taking into consideration the following experimental design aspects: o Cell format – current collector NMC cells or asymmetric lithium current collector cells o Data replication – number of cells per formulation and control cells o Electrolyte formula informed by Task 2 o Formation conditions – temperature, rest time, rest voltage, charge/discharge current density o Cell cycling conditions and data collection – Sand’s time, high-precision Coulometry, Coulombic efficiency, impedance, area specific resistance, cycle life to 80% capacity, rate performance o Post-mortem analysis – visual inspection of plated lithium, surface characterization by X-ray photoelectron spectroscopy, scanning electron microscopy of plated lithium with image analysis such as ImageJ Products: • Current Collector Testing Plan
