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

Tabea Sinn,Andreas Wolf,Hermann Nirschl,Wolfgang Witt,Thomas Stübinger,Marco Gleiß,Andreas Flegler

doi:10.3390/met10121617

Tabea Sinn, Andreas Wolf + Show 5 more

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https://doi.org/10.3390/met10121617

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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.

Highlights

The threat of global climate change and environmental pollution are, among other reasons, fueling the electric revolution in mobility [1], which in turn increases the demand for powerful batteries.Lithium-ion batteries (LIBs) are mostly regarded as most suitable battery type for this and other applications [2]
Centrifugation was investigated as a technique for a physical separation step of black mass into its components as part of a direct recycling process chain for lithium-ion batteries
Operated at fixed settings, tubular centrifuges do not deliver constant output properties, but separation conditions that diminish over time, which would not serve the purpose to recover pure fractions of LFP and carbon black

Summary

Introduction

The threat of global climate change and environmental pollution are, among other reasons, fueling the electric revolution in mobility [1], which in turn increases the demand for powerful batteries. Lithium-ion batteries (LIBs) are mostly regarded as most suitable battery type for this and other applications [2]. The performance of every LIB suffers from ageing mechanisms which inevitably lead to its withdrawal, eventually [3]. With a foreseeable increasing number of LIBs in use and withdrawn thereafter, the amount of LIB material that can and should be recycled increases since permanent disposal seems not to become a practical option for the upcoming mass of LIBs. Environmental issues again and scarce resources primarily drive the development of comprehensive, flexible and large-scale suitable recycling strategies for the valuable LIB materials [4].

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