Since their discovery, lithium batteries have dominated the energy storage sector, a dominance that has led to a notable increase in demand for this mineral.
This surge in demand has raised concerns about potential shortages, a situation that could result in price hikes and delays due to supply constraints.
In light of this scenario, the industry has been focused on searching for viable alternatives, with sodium emerging as a highly promising element to transform the market.
“It is an innovative technology that is about to enter the market, as its TRL is practically at 7 or 8,” says Lluís Trilla, Senior Researcher at the Catalonia Institute for Energy Research (IREC).
The Technology Readiness Level (TRL) assesses the maturity of a technology, where level 1 represents the most basic stage and level 9 indicates the most advanced phase.
It is a very similar technology in operational terms, with the difference that lithium is replaced by sodium and, instead of graphite, hard carbon is used in the anode.
These batteries are presented as a more economical and sustainable alternative to traditional ones.
The IREC Senior Researcher explains to Mobility Portal España that, although these cells lose a little energy density compared to lithium cells, they are “perfectly viable for urban vehicles.”
However, this technology still has a lower energy density than LFP, which is a crucial factor in high energy demand applications such as long-range electric cars.
What are the main differences between these two technologies?
First, lithium is a scarce and expensive resource, concentrated in a few regions of the world.
In this regard, Laura Cebrián, researcher on the RECILION project at the Instituto Tecnológico de la Energía (ITE), points out:
“It is a difficult material to obtain and its extraction has a high environmental impact.”
On the other hand, sodium is abundant and found in large quantities in the Earth’s crust and seawater, which makes it a more accessible, less expensive, less polluting and safer option.
Northvolt claims its carbon footprint is 10-20 kg CO2 per kWh, compared to 100-150 kg CO2 per kWh for LFP batteries.
Not only that, but they are also easier to recycle.
Despite their numerous advantages, sodium cells still face certain challenges before their mass adoption.
Currently, their manufacturing is more expensive due to low production volumes and the lack of a consolidated supply chain.
However, these costs are expected to decrease as implementation increases and technologies improve.
Companies that are already betting on sodium batteries
Stellantis Ventures has announced its stake in Tiamat, a French company that plans to build a gigafactory dedicated to the production of sodium batteries, with a capacity of 5 GWh.
This factory is expected to begin operations in 2025.
At the same time, Chinese brands such as JAC and JMEV have already launched the first electric vehicles equipped with these cells.
It is important to note that both companies are majority owned by two European groups: Volkswagen owns 50 per cent of JAC and Renault 50 per cent of JMEV.
BYD has announced the construction of a gigafactory with a capacity of 30 GWh for the production of sodium batteries for two of its most popular models: Seagull and Dolphin.
While European brands such as Dacia are also considering its adoption.
Another technology expected to hit the market is solid-state batteries, a process that involves changing the electrolyte in cells from a liquid to a solid state.
According to Lluís Trilla, these are still in an early phase of research and development, with a lower TRL.
