Scientists create new solid-state sodium-ion battery — they say it’ll make EVs cheaper and safer
Breakthrough battery technology could significantly improve the safety of batteries used for electric vehicles (EVs) and strengthen the stability of energy networks, scientists say.
Researchers have made a breakthrough by developing solid-state sodium-ion (Na-ion) batteries, which could one day complement and replace the lithium-ion (Li-ion) batteries used in many everyday devices today.
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Li-ion batteries, the dominant battery technology found in products ranging from cell phones to electric cars, can suffer from a process known as “thermal runaway.” This happens when a battery experiences a short circuit or physical damage, which sets off a self-sustaining chain reaction that dramatically increases the heat inside the cells.
Commercial Li-ion batteries also typically contain organic liquid electrolytes, which are an essential component for energy density, as well as efficient charging and discharging. These liquid electrolytes are highly flammable and can cause batteries to catch fire or even explodes when damaged.
Na-ion batteries could be a safer alternative because they contain more stable cathode materials and sodium ions have a lower electrochemical potential than lithium ions, making them less prone to thermal runaway.
The downside is that Na-ion batteries have a relatively low energy density compared to Li-ion batteries, meaning they last less time between charges. Additionally, Na-ion batteries can currently degrade more quickly, which would result in a lower overall lifespan. These two factors have historically prevented Na-ion batteries from becoming widespread.
But as noted in the new research, scientists have produced a solid material containing sulfur and chlorine that promotes conductivity in the same way as liquid electrolytes while providing much greater stability. The new battery had a Coulomb efficiency of 99.26% after 600 charge cycles at 0.1°C (a 10-hour discharge), close to the 99% or more achieved by lithium batteries.
Challenging lithium’s dominance
“We replaced the liquid electrolyte in the battery with a solid electrolyte – it is non-flammable,” Yang Zhaoprofessor in the Department of Mechanical and Materials Engineering at Western University, said in a video uploaded to YouTube.
The team also used the Canadian Light Source, Canada’s national light source. synchrotron facility, to examine the movement of ions inside their solid electrolyte, which confirmed their results.
“These X-ray tools allow us to see the local chemical environment, ionic pathways and binding structures in a way that conventional laboratory instruments cannot see,” Zhao said in another paper. statement. “They are absolutely essential to the development of solid-state battery materials.”
The new battery technology could contribute to widespread use of Na-ion batteries, particularly for critical workloads currently filled by more volatile Li-ion batteries, the researchers said. Next, they will need to demonstrate that their approach offers the right balance between safety and energy density, as well as a manufacturing method that can be scaled to meet the immense demand for batteries seen around the world.
Although it represents approximately 70% of the world’s rechargeable battery batteries, Li-ion batteries are primarily used in only a handful of critical applications.
For example, the recent initiative of the International Energy Agency (IEA) data found that the energy sector accounts for more than 90% of Li-ion demand.
Currently, domestic battery energy storage systems (BESS) are underestimated. scrutinyespecially after repeated fires at BESS sites in Californiaand require the construction of fire suppression systems. Na-ion could help ease these concerns and accelerate the deployment of BESS, which stores intermittent supply of renewable energy to be delivered later based on demand.
Since sodium is abundant compared to lithium, mass production of Na-ion batteries could significantly reduce the overall cost of the battery supply chain.
Na-ion batteries also have the added benefit of being easier to recycle than Li-ion batteries, as noted in a Study 2023because they contain fewer hazardous materials and no heavy metals.
A number of well-known automotive brands are already working on Na-ion batteries. In April, the world’s largest battery manufacturer, Contemporary Amperex Technology Co., Limited (CATL), announced that it was mass producing Na-ion batteries using its new “Naxtra” battery platform. The product is expected to be used in cars from 2026. Chinese auto giant BYD is also develop Na-ion batteries for network-wide storage purposes.
