Sodium-ion batteries offer promising technology
“Lithium-ion batteries are becoming a dominant technology in the world and they are better for the climate than fossil-based technology is, especially when it comes to transport. But lithium poses a bottleneck. You can’t produce lithium-based batteries at the same rate as you want to produce electric cars, and the deposits risk being depleted in the long term,” says Rickard Arvidsson. In addition to this, critical battery materials, such as lithium and cobalt, are largely mined in just a few places in the world, posing a risk to the supply.
The development of new battery technologies is moving fast in the quest for the next generation of sustainable energy storage – which should preferably have a long lifetime, have a high energy density, and be easy to produce. The research team at Chalmers chose to look at sodium-ion batteries, which contain sodium – a very common substance found in common sodium chloride – instead of lithium. In a new study, they have carried out a so-called life cycle assessment of the batteries, where they have examined their total environmental and resource impact during raw material extraction and manufacturing.
Today’s sodium-ion batteries are already expected to be used for stationary energy storage in the electricity grid, and with continued development, they will probably also be used in electric vehicles in the future.
“Energy storage is a prerequisite for the expansion of wind and solar power. Given that the storage is done predominantly with batteries, the question is what those batteries will be made from? Increased demand for lithium and cobalt could be an obstacle to this development,” says Rickard Arvidsson.
The major advantage of the technology is that the materials in the sodium-ion batteries are abundant and can be found all over the world. One electrode in the batteries – the cathode – has sodium ions as a charge carrier, and the other electrode – the anode – consists of hard carbon, which in one of the examples the Chalmers researchers have investigated can be produced from biomass from the forest industry. In terms of production processes and geopolitics, sodium-ion batteries are also an alternative that can accelerate the transition to a fossil-free society.“Batteries based on abundant raw materials could reduce geopolitical risks and dependencies on specific regions, both for battery manufacturers and countries,” says Rickard Arvidsson.
