Sustainable Storage: How Sodium-Ion Batteries Can Empower South Africa’s Energy Future

Abstract:

Sodium-ion batteries (SIBs) are gaining recognition as a sustainable and scalable option for energy storage, positioned to contribute meaningfully to an inclusive and equitable energy transition. In South Africa (SA), a nation grappling with frequent load shedding and a growing need for reliable energy storage, SIBs present a compelling alternative that balances affordability with strong technical potential. This article explores the role SIBs could play in strengthening grid stability, enabling rapid-charging infrastructure for electric vehicles (EVs), and providing long-duration energy storage through advanced high-voltage technologies. It highlights how these batteries could serve as a practical solution for promoting energy access, resilience, and youth-driven innovation across the country.

Introduction:

The growing global demand for energy is driving an urgent need for innovative energy storage technologies. As nations shift toward greater use of renewable energy sources, there is a rising requirement for both fast-charging solutions and large-scale stationary energy storage systems. As a result, rechargeable batteries are playing an increasingly vital role across various sectors, including portable electronics, electric vehicles (EVs), and grid-level storage. This trend has fueled a surge in demand for batteries that offer higher energy density, longer cycle life, lower cost, and are made from materials that are readily available and sustainable.

Rechargeable batteries, also referred to as secondary batteries, have the ability to store energy by converting electrical energy from an external power source into chemical energy during charging, and then releasing that stored energy as electrical power when needed. Among these, lithium-ion batteries (LIBs) have become widely favoured due to their excellent energy and power densities, long cycle life, and overall strong performance. However, the finite supply of lithium (Li) resources limits the capacity of LIBs to fully meet the growing global battery demand. Sodium-ion batteries (SIBs) have emerged as a highly promising alternative to LIBs, offering several key advantages, including lower manufacturing costs, the abundance of sodium (Na) as a raw material, and competitive energy density. Furthermore, SIBs bring additional benefits such as high specific capacity, reliable performance at elevated temperatures, enhanced safety, and environmentally friendly characteristics, positioning them as a strong candidate for future energy storage solutions.

SIBs are regarded as a more environmentally friendly option, as the extraction and processing of sodium typically require less energy and have a lower environmental footprint compared to some other battery materials. Chemically, SIBs share many similarities with LIBs, operating on comparable principles but substituting sodium for lithium as the charge-carrying ion. The larger ionic radius of sodium, however, introduces distinct electrochemical characteristics, which influence the choice of electrode materials and the overall cell architecture. Current research is focused on developing advanced high-voltage SIB cathode materials, such as layered transition metal oxides and polyanionic compounds, in combination with hard carbon anodes. Despite these efforts, SIBs have yet to achieve the commercial success of LIBs. This is largely due to the fact that the performance of key SIB components, including electrolytes and electrode materials, still lags behind the well-optimized counterparts found in LIB technology.

South Africa continues to grapple with chronic energy insecurity (persistent energy instability) and frequent load shedding, challenges that hit low-income and rural areas the hardest. Achieving a clean, dependable, and inclusive energy future for the nation will require the widespread adoption of advanced energy storage solutions that can effectively integrate intermittent renewable sources like solar and wind power. SIBs offer a promising pathway to address these needs, providing an opportunity to reduce dependence on diesel-powered backup systems and support affordable, decentralized energy storage in townships and off-grid regions. Notably, high-voltage sodium-ion configurations stand out for their potential to boost energy density while lowering overall system costs for grid-connected battery energy storage systems (BESS) and electric mobility solutions.

There are promising opportunities for the deployment of SIBs within South Africa’s evolving energy landscape. High-voltage SIBs are well positioned to help meet the country’s critical energy storage demands in several key areas:

1. Grid-connected BESS: High-voltage SIBs can play a vital role in delivering grid services such as frequency regulation, load shifting, and peak demand reduction, while also facilitating the integration of renewable energy sources like wind and solar. Their cost-effectiveness and scalability make them an appealing solution for municipalities, state utilities, and independent power producers looking to strengthen grid resilience.
2. EVs: As global momentum around EV research and development accelerates, SIBs emerge as a compelling choice for EV batteries. They offer lower manufacturing costs, improved safety performance, and strong compatibility with electric mobility applications. These advantages could help make next-generation energy vehicles (NEVs) more affordable and accessible, particularly in developing economies like South Africa.
3. EV charging infrastructure: The expansion of fast-charging networks depends on batteries that can deliver high power output and maintain thermal stability under demanding conditions. SIBs, with their superior safety characteristics at higher voltages, present a promising alternative for developing cost-efficient and reliable fast-charging solutions tailored to the needs of price-sensitive EV markets.

LIBs carry notable environmental and ethical issues tied to the mining of critical minerals, intensive water consumption, and challenges around recycling and safe disposal at the end of their life cycle. In contrast, SIBs offer a more sustainable and environmentally friendly alternative. Importantly, tapping into local sodium sources (such as seawater or residue salt from water desalination processes) has the potential to foster new industrial value chains that align with national strategic initiatives, including the South African Renewable Energy Master Plan (SAREM) and the Hydrogen Society Roadmap. This could support both economic development and the country’s transition to cleaner energy technologies.

Li-ion and Na-ion batteries share parallels in terms of performance characteristics, physical configuration, and production methods. Using comparable equipment and processes, these similarities have enabled manufacturers to leverage existing LIB production infrastructure to significantly accelerate progress in SIB development. Over the past decade, the scientific expertise and technological advancements gained through LIB research have been effectively applied to advance SIB commercialization efforts. One of the most promising outcomes of this synergy is the emergence of a diverse range of cathode materials suitable for SIBs, all relying on earth-abundant elements. This raises a critical and timely question: what specific knowledge and technological synergies from LIB development can be harnessed to further propel SIB innovation?

Establishing a domestic SIB industry in South Africa could play a vital role in tackling load shedding and advancing energy equity, delivering broad societal, economic, and environmental benefits. At the core of these efforts is the need for robust battery modeling and monitoring, which are essential for ensuring grid stability, supporting the integration of renewable energy sources, and enabling the widespread adoption of EVs. As South Africa advances it’s just energy transition (JET), it is crucial for policymakers to have access to evidence-based guidance on battery safety standards, lifecycle cost analyses, and the selection of optimal battery chemistries for national-scale deployment. Advanced battery modeling techniques capable of simulating internal battery behaviour and accurately estimating battery states are key tools for evaluating performance and understanding how batteries will operate under different conditions and applications.

Physics-based electrochemical models (both detailed and reduced-order) provide fast and dependable insights into key battery metrics, including terminal voltage, state of charge (SOC), state of health (SOH), state of power (SOP), remaining useful life (RUL), thermal behaviour, and cycle life. These insights are instrumental in refining battery designs to achieve superior performance. Additionally, such models are valuable for generating prognostic information within battery management systems (BMS), supporting predictive maintenance and safety measures. My research contributes directly to this field by enhancing the accuracy of state estimation, which is vital for the safe, reliable, and efficient operation of SIBs. Improved state estimation reduces the likelihood of battery failures, thus prolongs battery service life, and helps reduce the total cost of ownership thereby making clean energy storage solutions more accessible to communities with limited resources. This work advances energy justice and supports the achievement of Sustainable Development Goal (SDG) 7: Affordable and Clean Energy.

By enhancing the predictability and operational efficiency of SIB systems, my research lays important groundwork for the local manufacturing and deployment of these technologies. While much of the current SIB and hybrid modeling research originates from high-resource contexts (like, Europe and China) and often centers on Li-ion chemistries, there remains a significant gap in local, open-access datasets and models designed specifically for sodium-ion systems that address the unique environmental conditions and load demands of sub-Saharan Africa. Given that sodium is abundant within South Africa, this presents a distinctive opportunity to develop localized battery value chains, drive job creation, and strengthen industrial capacity in clean energy technologies. Ultimately, this work contributes to building foundational tools that empower African-led innovation in sustainable energy solutions.

In the long term, these advanced models have the potential to simplify system design, making it easier for small and medium-sized enterprises (SMEs) and local energy startups to roll out battery storage solutions confidently without relying on costly imported BMSs. In doing so, this research strengthens South Africa’s economic competitiveness in the growing global clean energy sector. This work is well aligned with the priorities outlined in the South African National Decadal Plan for Science, Technology and Innovation (2022–2032), especially within the key focus areas of energy security and climate change mitigation, digital futures, and the development of future skills and capabilities critical for a knowledge-based economy.

Youth Month presents the perfect opportunity to spotlight this cutting-edge battery technology. SIBs are especially important for South Africa’s youth and the country’s future. Advancing and implementing SIB technology will require the creativity, expertise, and strong capabilities of young engineers and scientists to lead innovation both locally and globally. SIBs offer multiple benefits: i) they open pathways for local manufacturing (fostering job creation, development of specialized skills, research opportunities, and youth-driven innovation), ii) they improve energy access for low-income communities, and
iii) they provide a practical, cleaner, and scalable energy storage solution for township mini-grids and rural electrification efforts.

Conclusion:

In summary, the development of (high voltage) SIB technology is closely aligned with national and regional objectives for delivering affordable, reliable, and sustainable energy. This article has explored the technological progress, promising opportunities, and key challenges linked to the deployment of SIBs in grid energy storage and fast-charging electric vehicle infrastructure.

As South Africa intensifies its focus on Fourth Industrial Revolution (4IR) technologies and green industrialization, the country is well-positioned to become a frontrunner in SIB research, pilot initiatives, and manufacturing. Strategic investments in local research and development, workforce skills enhancement, and collaborative industry partnerships will be essential to address existing challenges and unlock the full potential of this technology.

Khanyisile Masemola

I, Khanyisile, am an interdisciplinary researcher, writer, and PhD candidate in Electrical Engineering, at the University of the Witwatersrand. My work focuses on renewable energy systems, energy transition, and digital innovation, ensuring that technological advancements align with sustainability goals and equitable access. I have presented my work in various national conferences and have published several research articles in reputable journals, particularly the greater IEEE. In 2024, I received the prestigious GoldenKey award for outstanding research in energy transition and renewable energy systems for my MSc studies. In the same year, I was awarded as one of South Africa’s prestigious GradStar #Top100 most employable graduates and further awarded as one of the #Top10 future leaders. Beyond my academic achievements, I am deeply committed to leadership, STEM advocacy, and capacity building. I have contributed to the InnovateHer booklet project by African Female Voices, this STEM booklet is a 15-page guide designed to empower female students and leaders in high school to assist them with exam preparations and motivate them for their future journeys. I currently serve as a student member of the South African Institute of Electrical Engineers (SAIEE), a South African National Energy Association (SANEA) NPC Youth Member, and an active participant in Cigre Southern Africa and Cigre Women in Energy. I am passionate about education and regularly engages in initiatives such as the Sasol science fair called the Energy Innovation Challenge in collaboration with Nka’Thuto EduPropeller and the Eskom Expo for Young Scientists which aim to empower students, particularly young women, to pursue careers in science and engineering. I am a proud regional Ambassador of the South African AI Association (SAAIA) which hosts the grand AI Expo Africa conference every year. I am also a 2025 Black Women in Science (BWIS) Fellow, and a mentee for The Southern African Youth in Energy Sector (SAYES) Mentorship programme 2025 provided by the Southern African Energy Efficiency Confederation (SAEEC). Above all, Khanyisile is a firm Christian believer, believing in Jesus Christ as her Lord and Saviour.

The Intertwined Path: SDG 7, SDG 12, and South Africa’s Energy Future.

Empowering Youth for a Low-Carbon Future: Technical Skills and Entrepreneurial Pathways

2025 SAEEC 20th Annual Conference

NOMINATE HERE FOR SAEEC ENERGY AWARDS

APPLY OR RENEW YOUR MEMBERSHIP HERE