Solid-state batteries (SSBs) promise to bring substantial and critical improvements to cell and pack performance, notably in gravimetric and volumetric energy density, both of which will be necessary to reduce vehicle size, weight and cost. But the potential of SSBs will only be realised if the materials used to make the batteries can be produced cheaply enough. With this in mind, an emerging SSB cell manufacturer asked Exawatt to develop long-term forecasts for the manufacturing cost of certain novel materials that at the time were only being made in lab-scale quantities at high cost. By combining an assessment of the raw materials cost fundamentals with a learning-rate-based model for the materials manufacturing process at all scales, Exawatt was able to develop a forecast that indicated the SSB cell materials costs and prices would be competitive with those of existing technologies. This allowed our customer to plan the development of its technology with greater confidence.