Researchers from Washington State University and Pacific Northwest National Laboratory have created a sodium-ion battery that holds as much energy and works as well as some commercial lithium-ion battery chemistries. The breakthrough makes for a potentially viable battery technology using abundant and cheap materials. Researchers on the project have reported one of the best results to date for a sodium-ion battery.
The battery they created can keep more than 80% of its charge after 1000 charging cycles. Scientists say that the new battery is a major development for sodium-ion batteries. There is interest in many applications for replacing lithium-ion batteries with Na-ion units.
While lithium-ion batteries are used in many applications ranging from smartphones and laptops to electric cars, they are made using materials such as cobalt and lithium that are rare and expensive. Those materials are also found mostly outside of the United States. With the demand for electric vehicles and electricity storage increasing, the materials are harder and harder to come by. Scientists also say that lithium-based batteries are problematic in meeting the tremendous growing demand for power grid energy storage.
Sodium-ion batteries, on the other hand, are made using cheap, abundant, and sustainable sodium from the Earth’s oceans or crust. Batteries are also believed to be a good candidate for large-scale energy storage. The challenge right now is that they don’t hold as much energy as lithium batteries and have trouble being recharged as is required for efficient energy storage.
As part of the new research, the team created a layered metal oxide cathode and a liquid electrolyte that included extra sodium ions to create a saltier “soup” that had a better interaction with the cathode. The design electrolyte system allows for continued movement of sodium ions preventing an active surface crystal buildup and allowing for unimpeded electricity generation. The new cathode provided scientists with their best results ever for a sodium-ion battery. The team is currently working to improve the design by researching different materials that can be used in their construction.