Crossing the paths: the possible role of Co-based materials from lithium-ion battery recycling in the efficient electrocatalytic hydrogen production

Cobalt is worldwide recognized as a critical and strategic raw material due to its relevance in the rechargeable battery economy, combined with limited geological availability and uneven distribution. Cobalt is also emerging for the production of electrocatalysts for hydrogen production, thus entering also in the hydrogen economy. These two are the leading technologies in the energy storage and production sector, and are expected to grow even further in the mid term future. The mindful and optimized use of critical raw materials is thus pivotal, as it is urgent to combine the high technological performance (directly associated with the use of such materials) with their adequate supply, acceptable cost, environmental and societal sustainability. In this study, we propose a possible strategy to cross the path between the two ecosystems - rechargeable batteries and hydrogen economy - for the valorization of Co derived from the recycling of spent lithium-ion batteries in the production of electrocatalysts. The materials derived from the two main recycling strategies are fully characterized in terms of Co and carbon content, structure, and morphology, and subsequently electrochemically tested under half cell conditions in alkaline media for oxygen reduction reaction, oxygen evolution reaction and hydrogen evolution reaction, demonstrating the feasibility of valorization.