Bioleaching and bioelectrochemistry, eco-efficient technologies for the recycling of electric vehicle lithium-ion batteries. A review

Lithium-ion batteries (LiBs) are widely used today in many different applications. This provokes an increasing demand on critical raw materials (CRMs) which currently are difficult to obtain. This slows down the achievement of energy sovereignty. In this sense, recycling appears as a solution to avoid the over-exploitation of natural resources and to contribute to the energy self-sufficiency of the European Union. It is therefore necessary to develop efficient recycling processes as early as possible. In this sense, bioleaching and bioelectrochemistry have been raised to be a cost-effective and sustainable technologies, which can be applied sequentially to remove and recover critical metals from spent LiBs. According to the results obtained under optimised laboratory conditions, bio-produced acids have been reported to leach 80–100 % of Ni, Mn, Co and Li and bioelectrochemistry can achieve recovery rates in excess of 95 %. The main objective of this review is to present the recent advances in these technologies for batteries used in Electric Vehicles, which will allow the definition of the challenges that need to be addressed by research in order to achieve their implementation on an industrial scale. • World lithium-ion battery (LiBs) waste is expected to reach 112 GWh by 2030. • Recycling is the solution to avoid polluting and depleting natural resources. • Recent advances in bioleaching and bioelectrochemistry are summarised. • 80–100 % of the Ni, Mn, Co and Li from LiBs can be solubilised by bioleaching. • Bioelectrochemistry can achieve recovery rates of over 95 % for Ni, Mn, Co, Li.