This report aims at identifying and discussing how circular economy strategies may support the development of a sustainable battery value chain in Europe and what challenges, including data and information gaps, could hinder it. The aim is to keep product and materials value in the production loop as long as possible and avoid the use of mined Primary Raw Materials in the manufacturing phase. In order to achieve this, this report aims to assess the contribution of reuse, repurposing, remanufacturing, material substitution and recycling of Li-ion batteries to move the EU towards a Circular Economy for the Li-ion battery value chain. Myriad of raw and processed materials are used in the production of the Li-ion battery and this report will focus on the four most emblematic of them: Co, Li, Ni and natural graphite. The timeframe of the analysis starts from the past, goes through the present and looks at the future of the Li-ion battery value-chain. Preliminary conclusion of the analysis is that using the recycling of Li-ion batteries as Secondary Raw Material source and efforts to substitute specific materials are necessary and very important steps that will certainly mitigate supply issues of the incipient European Li-ion manufacturing industry. However, the availability of recycled Secondary Raw Materials is first conditioned by the access to the waste li-ion battery, which is obviously linked to the amount of li-ion battery put on the market and on how much of it is collected. Several obstacles are of political and regulatory nature, and a strong effort is required to European policy makers for removing them. The EU recycling industry should keep pursuing technological innovation to develop sustainable, scalable and flexible recycling processes able to deal with the incoming growing volumes of Li-ion battery waste and its expected uncertain chemical mix. For Electric Vehicle batteries, before recycling, the options for remanufacturing for reuse and repurposing in a second use applications are also interesting circular economy approaches capable of keeping materials and products value in the loop. However, the efficiency related to environmental, economic and safety aspects of reuse and repurposing practices is not yet properly assessed. It is of paramount importance to be able to estimate the stocks and flows of materials embedded in Li-ion batteries and quantify the present and future availability of secondary raw materials in different scenarios. A robust Material Flow Analysis model is necessary. In this report we propose a simplified Material Flow Analysis model that allows us to perform a qualitative analysis of stocks and flows of cobalt embedded in traction Li-ion batteries.JRC.C.1-Energy Storag