This Batteries Technology Development 2020 presents an assessment of the state of the art, development trends, targets, technological barriers and research and innovation needs for all solid state Li-ion batteries with lithium metal anodes, lithium-sulphur and sodium-ion batteries as well as redox flow batteries with organic shuttles. Particular attention is paid to how Horizon 2020 funded projects contributed to technology advancements. The report includes an overview of Member States' activities, most relevant international programmes as well as a patent landscape study for the latter three battery technologies.