Recovery of Critical Raw Materials from Batteries Emma Goosey

1 2, Karl Ryder

1, Martin Goosey

2

1Materials Centre, Department of Chemistry, University of Leicester, erg5@le.ac.uk,

2MTG Research Ltd,

Introduction

To limit environmental impacts caused by batteries the

European Commission in 2008, updated its regulations

with Batteries & Accumulators Directive (2006/66/EC)1.

This directive regulates battery chemistries (restricting Hg,

Cd, and Pb), collection and disposal routes, and

responsibilities, and recovery of materials from waste

batteries.

The EU battery market is set to grow considerably in the

near future, with a major contribution expected to come

from the electric (and hybrid) vehicles market.

The chemistries in batteries are quite diverse and ever

changing. Thus they can contain a large inventory of raw

materials. For the EU, recovering some of these materials

can mean resource market stability, reduced production

costs and lower environmental impacts2.

Process for the Recovery of Raw Materials from Batteries

A proposed methodology (Figure 1.) for the recovery of materials from batteries uses DES to get the

waste material into solution and then, after filtration, employs task specific ionic liquids (TSILs) to

selectively retrieve metals from the DES. Once metals are transferred into the TSILs, the metals can

be recovered through electro-winning, precipitation and electro-deposition.

Once all materials have been retrieved, stripping of residues from the DES allows a final clean-up of

the solvent, which can then be reused at the start of the process. Essentially, the process is cyclic and

allows for the regeneration and reuse of all the DES and ILs. This process therefore produces very

little waste, reduces costs and has a lower environmental impact compared to typical hydro- (acid

leaching) and pyro-(incineration) metallurgical processes, which are currently used to recover

materials from batteries.

A European project; CoLaBATS is midway through the process of designing and operating a pilot

plant for the recovery of Co and Ln from batteries with the use of DES and IL chemistries. A

summary of the developed chemistries is described below.

Hybrid Vehicle Market and Batteries

Hybrid vehicles can contain two types of batteries:

1. Industrial—power train (used to propel the vehicle),

2. Automotive—starter, lighter and ignition,

100% of batteries used in vehicles must be sent for recycling,

Lifetime of an industrial vehicle battery is ca. 5-10 years3

Recycling is the producers or suppliers responsibility and

recycling options include:

Repair—exchange of faulty cells for new ones,

Repurposing—good cells used for less-critical

applications,

Recovery—extraction of useful materials,

The directive requires that >50% material recovery must be

achieved from recycled batteries (excluding the casing),

By 2030 an estimated 10 million vehicles on UK roads will be

hybrid/electric4.

Ionic Liquids & Deep Eutectic Solvents

Ionic liquids (IL) and deep eutectic solvents (DES) are

categorised as salt solutions in which the ions are poorly

coordinated. Most commonly used in green chemistry

applications are room temperature ionic liquids (RTILs). The

physic-chemical properties of some of these solvents are often

what allows them to be thought of as green chemicals5:

- Liquid at < 100°C - Low vapour pressures

- High solute selectivity - Low combustibility

- Thermal stability - Low toxicity

- More environmentally benign

Conclusions and Expected Results

Novel DES and ILs have been created and are effective for the dissolution of metal mixtures.

The use of TSILs allows for specific recovery of individual metals, producing high grade raw

materials suitable for direct manufacturing use, and providing a higher return value for the

producer.

The metals retrieved from the batteries can be used to alleviate EU supply needs, aid market

stability and prevent the use of conflict minerals.

The designed process allows different battery chemistries to be handled in one single facility.

The chosen DES and ILs are less toxic than traditional hydro-metallurgical chemistries.

Little waste is produced from the process as a by-product.

Recovery of materials from batteries exceeds the current threshold of 50%.

References

1 Directive 2006/66/EC of the European Parliament and of the Council of 6 Septem-

ber 2006 on batteries and accumulators and waste batteries and accumulators 2 DEFRA, 2012. Resource security action plan: making the most of valuable materi-

als. Department for Business Innovation and Skills. Available online: https://

www.gov.uk/government/uploads/system/uploads/attachment_data/file/69511/

pb13719-resource-security-action-plan.pdf 3 Cairns, E.J., Albertus, P., 2010. Batteries for Electric and Hybrid-Electric Vehicles. Annu. Rev. Chem. Biomol. Eng. 2010.1:299-320 4 Committee on Climate Change, 2014. Meeting carbon budgets, 2014 progress re-

port to parliament. Presented to Parliament pursuant to section 36(1). and 36(2) of

the Climate Change Act 2008. 5 www.leicester-ils.co.uk/research

Acknowledgements

*Thanks to D2.2 Leaders in the CoLaBATS project, University of

Leicester for allowing use of figures. The CoLaBATs project has

received funding from the European Union’s Seventh Programme for

Research, technological development and demonstration under grant

agreement No 603482. For further project see: www.colabats.eu

Results

Metal content of shredded (black mass) lithium

ion (Li-ion) and nickel metal hydride (NiMH)

batteries were analysed via ICP-MS (Figure 2).

Concentrations vary between shredded batches

depending on variety of waste batteries

collected, manufacturer specifications and

amount of impurity metals present.

Leaching of the metals from the battery black

mass were tested with a variety of different

solvents including DES (Figure 3). Preferential

leaching of individual elements varied between

solvent type and concentration.

Leaching efficiencies (Figure 4) increased with:

exposure time of black mass in DES,

higher solvent temperatures,

higher additive concentration (5– 25%).

However, leaching efficiency did not increase

with DES volume, and leaching could be

optimised at 30:1 DES to black mass.

Figure 2. Metals in NiMH shredded batteries*

Figure 1. CoLaBATS battery recycling process.

Figure 3. Metal leaching from shredded batteries using

different solvents*

Figure 4. Metal leaching efficiency from 3—48 hours*