Reduced Energy Recycling of Lead Acid Batteries (RELAB)

Lead Research Organisation: Imperial College London
Department Name: Materials


The need to reduce energy demand is felt most keenly in the energy intensive industries (EEIs), of which the manufacturing of metals such as iron and steel, as well as non-ferrous metals, are a large constituent. The lead industry has in the last few decades developed effective processes for the recycling of metallic lead from (principally) lead acid batteries. The batteries are crushed (to remove the plastic), desulfurised, smelted and then refined to produce lead bullion which can be reused to make new batteries. Whilst very high rates of recycling are achieved, the entire process in very energy intensive, mainly from the milling and the smelting but also from the need to eliminate any lead-to-air emissions. Whilst the principles of this pyrometallurgical process have remained relatively unchanged for centuries, this proposal seeks to develop a novel solution-based electrochemical route to lead recycling using deep eutectic solvents (DESs).

Deep eutectic solvents have been applied to a number of different technological applications, owing to their relatively low cost, ease of handling, low environmental impact and, most importantly, their ability to dissolve a wide range of inorganic compounds - including oxides. We propose to dissolve lead paste - from lead acid batteries - in DESs and design novel electrochemical cells for the extraction of high purity metallic lead. This will be done in conjunction with Envirowales Ltd, a lead-acid battery recycler, as our project partner.

The main objective of the project is to develop a new electrochemical technology for lead-acid battery recycling based on a solution-based processing. We aim to understand the behaviour of speciation of Pb within the solvent, as well as the effects of secondary cations and electrode poisoning. We aim to design and build a number electrochemical cells (from bench-top to pilot plant prototype), that will replace the smelting steps in the current high temperature process. This will be supported by accurate total energy modelling of the current pyrometallurgical process with which to benchmark our energy gains by switching to the new technology. We envisage that not only will this technology have a lower overall energy demand, but will also be cleaner, due to a significant reduction in lead-to-air emissions.

Planned Impact

This project has secured the support of a UK-based secondary lead production company (EnviroWales Ltd) thus ensuring that the project team have excellent opportunities to maximise the commercial impact of this research. The outputs from the collaboration will help establish a strong UK business opportunity centred on the design, manufacture and utilisation of an emerging and highly versatile electrochemical technology. This would contribute to the growing increasing lead-acid battery market, which is currently worth over $30 billion, and projected to be $50bn by 2020. We are also developing a technology that has the added benefit of reducing the environmental issue to lead-to-air emissions from lead smelting.

As well as the direct economic impact of this work, there will be further academic impact, with the research team contributing to the scientific literature through high impact publications and presentations at many international conferences, such as the Materials Research Symposia (in both Europe and USA), Electrochemical Society meetings and also more technical lead-acid battery and market-orientated conferences.

A key aspect of our programme is the interaction with our industrial partner EnviroWales Ltd. They are providing us with waste battery material so the development of our process is based upon real feedstocks. They will also allow us full access to their plant to perform detailed process analysis of their current energy demands and efficiencies, as well as engaging with the project at our advisory board, and general industrial expertise. We will also provide training for three postdoctoral researchers who we would expect to go on to become research leaders in their field, providing direction to this research area, whilst developing future directions. These researchers will also engage in training, through collaboration with the CDTs, with the next generation of researchers, providing clear pathways to secure the future of this research area in the UK.

We will be fully engaged with the End Use Energy Demand Centres around the UK, participating in events and providing regular updates on our progress, and demonstrating advances.

Intellectual property will be fully protected through discussion with Imperial Innovations, a subsidiary of Imperial College responsible for technology transfer, and patents filed where appropriate. In terms of the manufacturing aspects of this work we will explore any opportunities to spin-out companies to further develop the technology used in this project.


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Description We are into year 4 of the 4 year award, and whilst there have been some key findings, we are currently in the process of patenting them so cannot divulge any more details yet.

We have published these papers:

- Developments in electrochemical processes for recycling lead-acid batteries. S.-Y. Tan, D.J. Payne, J.P. Hallett, G.H. Kelsall Current Opinion in Electrochemistry, 16, 83 (2019).
- Lead Acid Battery Recycling for the 21st Century. A. Ballantyne, J. Hallett, D.J. Riley, N.S. Shah, D.J. Payne, Open Science, 5, 171368 (2018).
Exploitation Route We are building a patent portfolio and look to commercialise in the future.
Sectors Chemicals




including Industrial Biotechology

Description Our first patent in 2018 (WO2016198872A1) was awarded in Europe and is being examined in China and the USA: - Electrochemical Recycling Of Lead-Based Materials. C. Poll, D.J. Riley and D.J. Payne. Our second patent (WO 2020/025970 A1) has just been published (2020): Recycling of lead- and tin-based materials. O. Hekselman, A.D Ballantyne, Y. Wang and D.J. Payne We spun out a company - Solveteq in 2021 and completed our first round of investment (£250k). In addition we were awarded £330k by InnovateUK
First Year Of Impact 2018
Sector Chemicals,Energy,Environment,Manufacturing, including Industrial Biotechology,Transport
Impact Types Economic

Description Sustainable Alternative to Informal Recycling of Lead-acid Batteries
Amount £210,347 (GBP)
Funding ID 83896 
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start 12/2021 
End 11/2022
Title Data from: Lead acid battery recycling for the 21st century 
Description There is a growing need to develop novel processes to recover lead from end-of-life lead-acid batteries, due to increasing energy costs of pyrometallurgical lead recovery, the resulting CO2 emissions and the catastrophic health implications of lead exposure from lead-to-air emissions. To address these issues, we are developing an iono-metallurgical process, aiming to displace the pyrometallurgical process that has dominated lead production for millennia. The proposed process involves the dissolution of Pb salts into the DES Ethaline 200, a liquid formed when a 1:2 molar ratio of choline chloride and ethylene glycol are mixed together. Once dissolved the Pb can be recovered through electrodeposition and the liquid can then be recycled for further Pb recycling. Firstly, deep eutectic solvents (DESs) are being used to dissolve the lead compounds (PbCO3, PbO, PbO2 and PbSO4) involved and their solubilities measured by inductively coupled plasma optical emission spectrometry (ICP-OES). The resulting Pb2+ species are then reduced and electrodeposited as elemental lead at the cathode of an electrochemical cell; cyclic voltammetry and chronoamperometry are being used to determine the electrodeposition behaviour and mechanism. The electrodeposited films were characterised by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). We discuss the implications and opportunities of such processes. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
Description RELAB 
Organisation Envirowales Limited
Country United Kingdom 
Sector Private 
PI Contribution Envirowales Ltd are a lead smelter in Ebbw Vale, South Wales, UK.
Collaborator Contribution They are providing us technical expertise and materials (lead paste) for our experiments.
Impact Too early.
Start Year 2017
Title ??????????? 
Description The present application relates to the electrochemical extraction of lead (Pb) from a lead- containing material using a deep eutectic solvent. This is of particular use in the recycling of the lead-based materials that result from energy generation processes. 
IP Reference CN107820521 
Protection Patent granted
Year Protection Granted 2018
Licensed No
Impact We have spun out a company (Solveteq) and we will use this as a vehicle to exploit the IP generated through RELAB.
Description The present application relates to the electrochemical extraction of lead (Pb) from a lead- containing material using a deep eutectic solvent. This is of particular use in the recycling of the lead-based materials that result from energy generation processes. 
IP Reference WO2016198872 
Protection Patent application published
Year Protection Granted 2016
Licensed No
Impact We have had this patent granted in Europe and it is being examined in the US and China.
Description This invention relates to the electrochemical extraction of lead (Pb) from a lead-containing material. This invention is particularly useful for the recycling of the lead-based materials that result from energy generation processes, such as the waste products from lead acid batteries and spent lead perovskite solar cells. 
IP Reference EP3308419 
Protection Patent granted
Year Protection Granted 2018
Licensed No
Impact We have spun out a company, Solveteq, which will be the vehicle for us to exploit the IP generated in this project.
Description This invention relates to a process for obtaining lead (Pb) and/or tin (Sn) from a lead- and/or tin-based material using a deep eutectic solvent. 
IP Reference WO2020025970 
Protection Patent application published
Year Protection Granted 2020
Licensed No
Impact We have spun out a company, Solveteq, which we will use to exploit the IP generated with the RELAB project.
Company Name Solveteq 
Description Solveteq develops sustainable automotive battery recycling technology. 
Year Established 2020 
Impact We have raised £250,000 from private investment and will be raising more money in 2023. Solveteq's CEO, Dr Ola Hekselman, has just been awarded a £50,000 Women in Innovation Award by InnovateUK.
Description Great Exhibition Road Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact We had a stand at the Great Exhibition Road Festival from 28-30 June 2019. The Great Exhibition Road Festival is a three-day celebration of curiosity, discovery and exploration in South Kensington. The Festival is a collaboration between 19 cultural institutions including Imperial College London, the Natural History Museum, the Science Museum, the V&A and the Royal Albert Hall. It attracts over 20,000 visitors.
Year(s) Of Engagement Activity 2019