Investigation of Centrifugal Fractionation with Time-Dependent Process Parameters as a New Approach Contributing to the Direct Recycling of Lithium-Ion Battery Components

Abstract

Recycling of lithium-ion batteries will become imperative in the future, but comprehensive and sustainable processes for this are still rather lacking. Direct recycling comprising separation of the black mass components as a key step is regarded as the most seminal approach. This paper contributes a novel approach for such separation, that is fractionation in a tubular centrifuge. An aqueous dispersion of cathode materials (lithium iron phosphate, also referred to as LFP, and carbon black) serves as exemplary feed to be fractionated, desirably resulting in a sediment of pure LFP. This paper provides a detailed study of the commonly time-dependent output of the tubular centrifuge and introduces an approach aiming to achieve constant output. Therefore, three different settings are assessed, constantly low, constantly high and an increase in rotational speed over time. Constant settings result in the predictable unsatisfactory time-variant output, whereas rotational speed increase proves to be able to maintain constant centrate properties. With further process development, the concept of fractionation in tubular centrifuges may mature into a promising separation technique for black mass in a direct recycling process chain.

A toolbox for improved recycling of critical metals and materials in low-carbon technologies

“…Using high accelerations (similar to fractionators), the use of centrifugation was reported to separate lithium-containing materials from carbon-black of spent LiBs. 104 Physical techniques are promising for the recycling of emerging end-of-life materials as they are mature and easy to implement on an industrial scale. However, these techniques are used for pre-concentration purposes and the purity of recovered metals is oen too low aer their application.…”

Roadmap for a sustainable circular economy in lithium-ion and future battery technologies

“…Advances in the understanding of the magnetic susceptibility of the cell components will allow for more selective separation of active materials. Separation of conductive carbon from the active material will allow further flexibility in the recycling of active materials, separating the conductive additives and binders from the potentially outdated active material which may have lost the necessary structure to perform adequately [129,130].…”

Autonomous Processes in Particle Technology

“…Generally, adjustments can be made via the operational parameters, i.e., rotational speed and feed flow rate, whereby the model‐based increase of rotational speed has been examined in the experiments elucidated below. More detailed information can be found in 38. It is worth noting that the properties of LFP particles require strong centrifugal forces and a tubular centrifuge was the first choice, justified under research conditions.…”

“…The mentioned model for fractionation of LFP and CB in a tubular centrifuge was correspondingly applied to design a model‐based feed forward control for first examinations within a feasibility study for the intended adjustment of rotational speed. The entire study and more background information is accessible in 38. The aim of the study was to prove that the model‐based rotational speed increase results in the desired output over the entire operational time, namely a constant particle size distribution in centrate.…”