Jasmyn Shah, energy and carbon analyst, Salix
As we work with projects at Salix, and review technologies, we understand why batteries are recognised as a vital component of a secure and resilient energy system.
Whilst a large part of our work at Salix is supporting governments and delivering decarbonisation programmes for the public sector as well as housing, we are always looking at technologies being developed that could have an impact on our energy future.
There is certainly development happening regarding batteries. They are an important part of the energy picture, because by storing excess electricity and releasing it when demand is highest, they help ease pressure on the grid, improve energy security, and support the transition to a low-carbon economy.
In fact, Lithium-ion batteries have been the leading energy storage solution since the 1990s. They dominate the market due to their high energy density, long lifespan, extended cycle life, fast charging capabilities, versatility and high efficiency.
However, their production relies on increasingly scarce materials such as lithium, cobalt and nickel. The extraction of these materials is a highly energy and water intensive process and can lead to habitat destruction, water contamination and air pollution, damaging local ecosystems.
Equally, since many of these metals are found in less developed nations, the exploitative nature of extraction poses significant health and social risks. Furthermore, supply chain constraints and price volatility is increasingly tied up with geopolitical instability and growing global demand, particularly from the electric vehicle and electronics sectors, reducing resource security.
Lithium-ion batteries also pose several safety and environmental issues, both in use and disposal. The materials used are highly reactive, creating a risk of thermal runaway and fire. Likewise, improper disposal can result in hazardous substances being leached into soil, groundwater and waterways, causing damage to the local environment.
In response to these challenges, there has been increasing investment into the development of innovative energy storage solutions, which can offer improved sustainability, safety and long-term resource security.
One of the most promising alternatives to lithium-ion batteries is sodium-ion batteries.
Like lithium-ion batteries, sodium-ion batteries are rechargeable energy storage systems that operate by exchanging ions between positive and negative electrodes during charging and discharging cycles. The difference is that they use sodium rather than lithium as the primary charge carrier. Sodium can be found abundantly and is readily available in seawater and the Earth’s crust, offering a more a secure and accessible alternative to lithium.
In addition, sodium-ion batteries do not require cobalt, nickel and copper to the same extent as lithium-ion batteries. Instead, they can utilise more abundant and cheaper materials such as iron-based compounds. This has the potential to reduce dependence on increasingly scarce raw materials, improve supply chain resilience, reduce production costs and minimise the use of ethically and environmentally contentious materials.
Sodium-ion batteries offer several additional advantages. Their reliance on abundant materials can make them a lower-cost energy storage solution, particularly as production scales up. Supply chains are generally less exposed to geopolitical risks and resource constraints, as these raw materials are both more accessible and cheaper, reducing price volatility in production.
Furthermore, sodium-ion batteries continue to perform well in low-temperature environments, with lower rates of degradation than many lithium-ion batteries. This makes them especially suitable for applications in regions where cold weather can adversely affect battery health and reliability. Additionally, sodium-ion batteries exhibit greater chemical stability compared to lithium-ion batteries, reducing the likelihood of overheating and combustion.
The sodium-ion battery may appear to offer the ideal alternative to lithium-ion batteries, with more abundant and lower-cost materials, reduced environmental impacts and improved performance in colder temperatures. However, there are some constraints which hinder their widespread adoption, and prevent them from replacing lithium-ion technologies across all applications.
Sodium-ion batteries are significantly less mature than lithium-ion batteries which presents several challenges. One of the main limitations is that they have much lower energy density than lithium-ion batteries. In practice this means that much larger and heavier batteries are required to store the same amount of energy and achieve equivalent performance than with a lithium-ion battery. This limits their suitability for applications such as electric vehicles, where battery weight and density are critical factors.
In addition, as sodium ions are larger and more reactive than lithium, the repeated movement during charging and discharging can place greater stress on electrode materials. This can accelerate degradation and reduce the life cycle of these batteries, reducing the performance over time.
So, is the UK ready for a transition towards sodium-ion batteries? Realistically lithium-ion batteries are likely to remain the dominant energy storage technology for the foreseeable future. However, sodium-ion batteries are well positioned to complement, lithium-ion batteries rather than replace them. Due to their lower material cost, improved safety characteristics and strong performance in cold temperatures, sodium-ion batteries could be suitable to applications where weight, size and energy density are less critical.
One of the most promising uses could be for grid-scale energy storage, where the affordability and abundance of sodium offer significant advantages.
In these applications, the low energy density of sodium-ion batteries is less of a concern, as the batteries can be designed around the available space, rather than strict weight constraints. This would allow the limited supply of lithium and other raw materials to be prioritised for sectors where high energy density is essential, such as electric vehicles, portable electronics and aviation applications.
At Salix, we will continue to research and support emerging technologies like sodium-ion batteries to support the UK’s growing energy storage needs, and contribute to a more resilient and sustainable energy system.
We have also launched our podcast Tomorrow’s Energy to explore further the technologies and talk to the people driving our future.
All episodes are available for streaming or download from your preferred podcast platform including Apple, Amazon and Spotify. The recordings are also available from our website.
I am looking forward to seeing what happens next, as our energy future changes and we open our minds up to all kinds of new possibilities.
This article appeared in the October 2026 issue of Energy Manager magazine. Subscribe here.
