The inventor of the lithium-ion battery is developing sodium-ion batteries as a cheaper alternative. Sodium, the main component of salt, is cheaper and more abundant than lithium.
The study is done by Professor John Goodenough, inventor of the lithium-ion battery, and his team from Cockrell School of Engineering at The University of Texas at Austin.
Sodium-ion batteries work just like lithium-ion batteries. During the discharge, sodium ions travel from the anode to the cathode, while electrons pass to the cathode through an external circuit. The electrons can then be used to perform electrical work.
Although sodium-ion batteries hold tremendous potential, there are obstacles to advancing the technology including issues related to performance, weight and instability of materials.
The team identified a new cathode material to address the instability. Its structure consists of fixed sodium and iron layers that allow for sodium to be inserted and removed while retaining the integrity of the structure.
The new cathode material is made of the nontoxic and inexpensive mineral eldfellite. It presents a significant advancement in the race to develop a commercially viable sodium-ion battery. The researchers reported their findings August 27 in the journal Energy & Environmental Science.
“At the core of this discovery is a basic structure for the material that we hope will encourage researchers to come up with better materials for the further development of sodium-ion batteries,” said Preetam Singh, a postdoctoral fellow and researcher in Goodenough’s lab.
One challenge the team is currently working through is that their cathode would result in a battery that is less energy dense than today’s lithium-ion batteries. The UT Austin cathode achieved a specific capacity (the amount of charge it can accommodate per gram of material) that is only two-thirds of that of the lithium-ion battery.
“There are many more possibilities for this material, and we plan to continue our research.” Singh said. “We believe our cathode material provides a good baseline structure for the development of new materials that could eventually make the sodium-ion battery a commercial reality.”