Computational modelling and experimental science for sustainable energy storage, mineral processing and alloy development

“We have such a lot of potential insight and capacity in Africa which can contribute towards the whole wellbeing of the world and the good of humankind.”

Prof. Phuti Ngoepe, GCRF START Co-Investigator, Director Materials Modelling Centre, University of Limpopo, South Africa

Computational modelling and experimental science have always gone hand in hand. In the past, in my research, this was with laser spectroscopy to extract optimum information from both techniques. Now we have built up the base for computer modelling here in Southern Africa, the GCRF START grant will help us take experimental science, simulations and capacity building even further, addressing global energy and climate challenges, building on more than 30 years of successful collaboration with UK scientists.

My name is Phuti Ngoepe, and I am Senior Professor and Director of the Materials Modelling Centre at the University of Limpopo (UL) in South Africa and a GCRF START Co-Investigator.  Our group uses computational modelling to study materials related to energy storage, mineral processing and alloy development themes. This research contributes to important energy and climate Sustainable Development Goals by investigating energy materials (including raw materials) for improvements in batteries central to the development of electric vehicles, solar energy storage and electricity utility backups.  Efficient mineral processing methods, which focus on water, energy and environmental conservation in the mining sector, are becoming imperative in Africa. Therefore, ‘greener’ water conserving and cost-effective approaches to mineral recovery and processing are also explored.

These themes are studied through collaborations with experimental teams using UL’s computational facilities and a petascale national computational facility at the South African national Centre for High Performance Computing (CHPC) in Cape Town, using a wide range of academic and commercial software for simulations.  Specific areas of study include computational approaches to produce nanostructures for cathodes of Li-ion batteries and emerging batteries, beneficiation of raw materials within all three themes of energy storage, and mineral processing and alloy development.

Phase stabilities of precious and light metal alloys have been examined from a combination of energetics, elastic properties and phonon dispersions, providing valuable information for aerospace applications, shape memory devices and generally powder metallurgy processing. The latter is undertaken in collaboration with South Africa’s Council for Scientific and Industrial Research (CSIR) and the University of South Africa (UNISA), the University of Cardiff (UK) and University College London (UK). Commercialisation processes are continuously pushing us out of our comfort zones, and we have even stretched ourselves to image and imitate processes that take place inside reactors in industrial pilot and production plants to help understand and solve challenging problems.

A decade ago, the mineral processing industry in South African mines approached South African universities, including UL and the Department of Science and Innovation (DSI) to employ blue sky research in modernising ways of mining and mineral extraction. In response, our group has developed stability protocols for metal sulphides hosting precious metals and proofs of concept, using computational modelling for the design of reagents that can efficiently extract metals from mineral ores, including those occurring in the Limpopo Province here in South Africa. Mineral processing is conducted with the University of Cape Town (UCT), the BGRIMM (Beijing General Research Institute of Mining and Metallurgy, China) and South Africa’s mineral mining research organisation, Mintek.

Prof. Phuti Ngoepe, Director of the Materials Modelling Centre at the University of Limpopo in South Africa and GCRF START Co-Investigator. ©Diamond Light Source

African perspectives on impact: energy storage solutions, capacity building and job creation

Ultimately, the potential impact of our collaborative research is huge.  For example, improved battery solutions for solar energy storage in Africa would mean better access to clean, affordable energy for working, cooking and learning at any time of the day or night. In addition, more efficient batteries in devices like mobile phones brings hope that one day phone batteries could be recharged just once a year!  The latter would make a huge difference to our rural people, the majority of whom rely on cell phones for communication but often struggle to access reliable energy sources to recharge.  With regards to industry and job creation, most of the materials involved in making the compounds we are investigating are mined in our region, such as manganese ores (South Africa has 80% of the world’s manganese ores), which means in terms of their beneficiation, we have possibility to harness the benefits locally by establishing industries related to energy storage.

Of course, impact is not just about scientific results; it is also about building the expertise of people. All our programmes have played and continue to play an important role in the training of postgraduate students and emerging researchers in South Africa and further afield. Much of this capacity building has benefitted from a fruitful collaboration of more than 30 years with Professor Sir Richard Catlow, Professor of Catalytic and Computational Chemistry at the University of Cardiff and Professor of Chemistry at University College London in the UK. Initially funded by The Royal Society, London (UK), and South Africa’s National Research Foundation (NRF), this partnership has afforded UK and African scientists opportunities to share skills, build capacity, and get involved in diverse and sustainable projects related to energy storage, mineral processing and alloy development. Today, our energy storage programme at the University of Limpopo is broad and involves several researchers and postgraduate students, with national and international collaborators from the South African Energy Storage Research Initiative (ESRDI), and from leading research organisations in the UK, USA and China.

We have produced highly competent systems administrators, many of whom are now based at other institutions and thus have been able to grow the capacity in computer modelling in our country. Students who qualified for PhDs in our programmes have continued and established computer modelling activities at other research institutions/universities, such as the University of South Africa (UNISA), Tshwane University of Technology, amongst others. National Laboratories such as the CSIR, Centre for High Performance Computing, Statistics South Africa, and commercial companies and SOE like Johnson and Matthey, Microsoft SA and Transnet are a few of the many high-profile labs we have been able to connect with in this way. The GCRF START grant will further assist us in our mission to develop expertise and people to take up leadership positions in South Africa and across the African continent, sharing their African perspectives on science with their counterparts in the UK.

Prof. Phuti Ngoepe, Director of the Materials Modelling Centre at the University of Limpopo in South Africa and GCRF START Co-Investigator. ©Diamond Light Source

A very promising START! Setting up of a new Li-ion battery cathode synthesis laboratory

“It is important that we invest for the long term and that the African scientific community engages with synchrotron science with the view to an African synchrotron being a reality in the not too distant future.” 

Professor Sir Richard Catlow, GCRF START Co-Investigator, The Royal Society, London; Cardiff Catalysis Institute (UK) and University College London (UK).

In terms of the science, the GCRF START grant enables us to use the latest synchrotron techniques on Diamond beamlines such as Extended X-ray Absorption Spectroscopy techniques (EXAS) and X-ray atomic pair distribution function (PDF), with our simulations complemented by experiments using samples produced from our new Li-ion Battery Cathode Synthesis Laboratory to help us understand how structural and electronic properties of the battery materials can be improved, especially in relation to the charging and discharging of batteries. 

The Li-ion Battery Cathode Synthesis Laboratory is being commissioned and co-ordinated by Dr Noko Ngoepe at the University of Limpopo. Dr Noko Ngoepe has the necessary experience through working with the cathode materials group which runs the manganese-based pilot plant in Nelspruit, and through his collaboration with the Argonne National Laboratory (USA) on the synthesis of the Nickel-Manganese-Cobalt (NMC) cathode materials. The products are lined up for further fluorination processing in South Africa, and for characterisation at Diamond together with our GCRF START Post-Doctoral researcher, Dr Cliffton Masedi.

This research also complements work carried out at the Cathode Materials Pilot Plant based in Nelspruit, South Africa, which was launched in Nelspruit in October 2017. It aims to see beneficiated manganese-based cathode materials for lithium-ion batteries developed locally at highly competitive costs, using South African raw materials. Our research is mainly intended to produce manganese rich cathode materials using the synthesis reactor. These materials will be characterised at UL and other collaborating institutions in South Africa that are participating in the Energy Storage Research Development Initiative, supported by the South African Department of Science and Innovation. It is further envisaged that some of the synthesised cathode materials will be doped in order to enhance their stability. 

Aerial view of Diamond Light Source Ltd, Harwell Campus, UK. ©Diamond Light Source

Nanostructures for cathodes of Li-ion batteries and emerging batteries

High energy density batteries are central to development of electric vehicles, solar energy storage and electricity utility backups – crucial in mitigating adverse effects of global climate change. In terms of vehicle batteries, the three major considerations are the distance vehicles such as cars can travel before recharging their batteries; how quickly the batteries can be charged; and reasonable prices of batteries. Our research is contributing to global research efforts that will ultimately produce safe, cheap, ‘green’ batteries with a longer life cycle, increased storage capacity, a wider optimal temperature operating range, and higher power output.  Many of the technologies are there, it is now a question of how to improve them: how to increase the range of travel, the length of use, how to reduce cost, and how to reduce the carbon footprint.

The enhanced performance of batteries is now achieved with nano-architecture electrodes which is at the core of what we are doing. We use world leading computational approaches to produce such nanostructures for cathodes of Li-ion batteries and emerging batteries. Valuable insights are shed on disruptive structural changes that occur during charging and discharging, and how these can be brought under control. The electrodes we study consist of nanoparticles that aggregate to form bigger/secondary particles. The nano-architecture helps to increase the capacity of the batteries, the coherence and stability of which during operation, is vital.  Currently, computational modelling studies of manganese-based cathodes such as the spinel lithium manganese oxides and manganese rich NMCs of these are explored, predicting structural stabilities, especially during charging and discharging in order to ensure long life of the batteries. These predictions guide where to put emphasis on experiments and aid in the interpretation of results. For this, access to the UK’s national synchrotron, Diamond Light Source (Diamond) with the START grant will be of enormous value.

Lithium-ion battery. Photo credit Rebekka Stredwick. ©Diamond Light Source

The impact for humanity and our planet is worth it!

“It takes more than a scientist to put things together. One must have one’s feet in different worlds: capacity building, relevance, the requirements of the science itself, and sustainable funding – it is a huge demand but worth it for humanity!”

Prof. Phuti Ngoepe, GCRF START Co-Investigator, Director Materials Modelling Centre, University of Limpopo, South Africa

With climate change and increasing socio-economic challenges facing both developing countries and the developed world, it has become more pressing than ever to invest in the next generation of scientists, and find novel, cost effective and clean energy storage solutions for the good of humanity and our planet. Most recently, during the global Covid-19 ‘lockdown’, we have watched how the world reduced its human activity (such as fossil fuel emissions) and for a short time in places nature bounced back! Yet creating sustained, lasting impact takes time and investment, as demonstrated by our research collaboration successes with the UK and others. In the space we find ourselves now (the ‘new normal’) how are we in Africa and the UK going to redefine our parameters for the benefit of future generations? What kind of world do we want to see post-Covid-19?  Collaborating well into the future with synchrotron science through the GCRF START grant is one positive answer to these difficult questions and the global challenges we all face.

It is an opportune time to strengthen this approach, as we are now in the era of Big Data, and the amount of data coming from various experimental facilities requires an integrated approach with modelling and simulation to exploit new approaches, such as Artificial Intelligence and Machine Learning. This GCRF START grant opens new avenues for exploring more hidden parameters and presents us with good opportunities.”

Dr Happy Sithole, Director of South Africa’s Centre for High Performance Computing (CHPC) and Centre Manager of the South African National Integrated Cyber infrastructure System (NICIS).

“It has been hugely rewarding working with Phuti and colleagues and with other African scientists over the last 30 years. I first visited the University of the North (now University of Limpopo) in autumn 1994. I met Phuti and a young colleague working enthusiastically in a small computer lab with one Silicon graphics machine. Over the ensuing decades we have seen develop, from this very modest beginning, a strong and successful centre that has not only produced excellent science but has populated, universities and research centres with its graduates. And I am very pleased and proud that UK scientists were able to contribute to this remarkable achievement.” – Prof. Catlow, GCRF START Co-Investigator, Foreign Secretary and Vice President at The Royal Society, London (UK), Professor of Catalytic and Computational Chemistry at Cardiff Catalysis Institute (UK), and Professor of Chemistry at University College London (UK).

Professor Sir Richard Catlow, GCRF START Co-Investigator, Professor of Catalytic and Computational Chemistry at the University of Cardiff, and Professor of Chemistry at University College London in the UK. Photo credit: The Royal Society. ©Diamond Light Source
Click here to read more about the UN’s Sustainable Development Goals.

About Prof. Phuti Ngoepe

Prof. Phuti E Ngoepe is Senior Professor, Director of the Materials Modelling Centre at the University of Limpopo and holds the South African Research Chair on Computational Modelling of Materials. Awarded South Africa’s Order of Mapungubwe Silver, Prof. Ngoepe is a Founder Member of Academy of Science South Africa. Click here for a full biography. Prof. Ngoepe is a GCRF START Co-Investigator.

Prof. Phuti Ngoepe’s Publications

About Prof. Sir Richard Catlow

Prof. Sir Richard Catlow is Foreign Secretary and Vice President at The Royal Society, London, Professor of Catalytic and Computational Chemistry at Cardiff Catalysis Institute (UK), Professor of Chemistry at University College London (UK), and a co- founder of the UK Catalysis Hub. Professor Catlow develops and applies computer models to solid state and materials chemistry — areas of chemistry that investigate the synthesis, structure and properties of materials in the solid phase. “By combining powerful computational methods with experiments, Richard has made considerable contributions to areas as diverse as catalysis and mineralogy.[1]Prof. Catlow is a GCRF START Co-Investigator.

Prof. Sir Richard Catlow’s Publications


[1] Source: The Royal Society: