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Environmentally friendly, sustainable and commercial-scale production of highly pure ‘battery-ready’ leady oxide via hydrometallurgical processing of spent battery paste

Our aim is to revolutionise the art of recycling through science, ethical practice, sustainability and technology. Our vision is a web of industries, where one stream's waste is another stream's feedstock – bridging linear and wasteful processes to create circular, energy efficient, non-polluting, zero-waste industries. Our stepping stone towards this vision is a technology for the recycling of lead-acid battery (LAB) paste.

The lead-acid battery (LAB) market is forecast to reach $84 billion USD by 2025 (source: Report ID 4076564, Research & Markets, January 2017). Despite intense competition from alternative and emerging energy storage solutions, LABs continue to deliver the most proven, low-cost, safe and affordable option for electrical energy storage. Indeed, LABs are used widely in automobiles, traction and heavy industry, telecommunications, emergency lighting, renewable energy systems, medical equipment, railway backup systems, oil and gas exploration, and more.

The recycling of LABs via current methods is energy intensive and wasteful. In some parts of the world it produces ‘smelter smoke’ – a toxic mixture of sulphur dioxide, nitrogen dioxide and very often lead metal particles. For this reason, although LABs are the world's most successfully recycled commodity product – a successful multi-million tonne circular economy – the incumbent recycling processes are in need of innovation and modernisation.

Invented in 2006 by Professor Vasant Kumar at the University of Cambridge,1-3 UK, the technology was licensed exclusively in 2016 to Aurelius for further development, scaling up and commercialisation. Our piloting efforts are funded by two Innovate UK awards, a Horizon 2020 Phase 2 SME grant, and our turnover from the collection, dismantling and processing of more than 10,000 tonnes of LAB scrap per year.

The patented hydrometallurgical process, branded as FenixPb, delivers a critical improvement to the lead recycling industry. It enables conversion of spent battery paste to leady oxide (Pb/PbO) without producing or handling an intermediate ingot, and without utilising electrowinning. Our process reduces the carbon footprint by 80-89%; eliminates noxious gases (including sulphur dioxide) at no added cost; reduces overall slag burden by more than 90%; and produces energy (this is because a key stage in the process is highly exothermic, releasing rather than consuming energy).

The process produces battery-ready leady oxide of high quality and purity (more than 99.99%) directly from waste battery paste. Moreover, the leady oxide is nanostructured and has been shown to improve the energy density, cycling and life of the battery. With our process, it is possible to control the ratio of alpha-to-beta lead oxide, enabling production of lead-acid batteries for specific applications. Importantly, the production of leady oxide via our hydrometallurgical process is more cost-effective than the incumbent production of leady oxide using the Barton pot or ball-mill methods.

The technology is due to be commercialised in 2019. Pilot plants are currently being constructed in Brazil and the United Kingdom.


1) M.S. Sonmez, R.V. Kumar, Hydrometallurgy, 95 (2009), 82-86.
2) M.S. Sonmez, R.V. Kumar, Hydrometallurgy, 95 (2009), 53-60.
3) J. Yang, R.V. Kumar, D.P. Singh, J. Chem. Technol. Biotechnol., 87 (2012), 1480-1488.

Athan Fox

Chief Technology & Innovation Officer, Aurelius

Athan is a PhD graduate in Chemistry from the University of Cambridge and a part-qualified UK patent attorney. His previous roles include Technology Transfer at Cambridge Enterprise and management of a chemical research laboratory at the University of Cambridge. Athan’s core interests include the development of new and ground-breaking technology to address the world's challenges in sustainability, recycling and the circular economy - to bring about a 'world without waste'. He was selected to represent the UK and the European Commission on multiple government-led missions to Japan, South Korea, Indonesia, Europe and the Middle East.

In January 2019, Aurelius Environmental won two prestigious Rushlight awards in London, UK. Between 2016 and 2018, the company secured grant-funding of more than £2 million GBP including a Horizon 2020 Phase 2 SME, Innovate UK Newton Fund, and Innovate UK Open Programme awards. Athan is an Executive member of Aurelius Environmental and is involved in technology, research and innovation strategy, technology transfer and commercialisation of the Aurelius value propositions.