The world has witnessed the exponential growth of battery technology over the years. Along the timeline, batteries have become extremely sophisticated and compact and capable of powering more complex devices. However, this growth is also accompanied by the concerns of lithium depletion, the metal that constitutes the core of new rechargeable batteries.
On a brighter side, researchers at the Georgia Institute of Technology have found that batteries based on sodium and potassium can be potential alternatives for lithium batteries as revealed by recent findings.
According to Matthew McDowell, an assistant professor in George W. Woodruff School of Mechanical Engineering, sodium- and potassium-ion batteries tend to decay and degrade faster and hold lesser energy than other alternatives although that’s not always the case.
In a study sponsored by National Science Foundation and the U.S. Department of Energy, the research team monitored how the three different ions of lithium, sodium, and potassium reacted with particles of iron sulfide. As batteries charge and discharge, the ions constantly react and penetrate the particles that form the battery electrode causing considerable volume changes to the electrode particle. Given the size of lithium and sodium being bigger than lithium, it was believed traditionally that sodium and potassium might cause significant degradation while reacting with particles. However, in an experiment to view the reaction with an electron microscope it was observed that iron sulfide was more stable reacting to sodium or potassium than with lithium, indicating that batteries based on sodium and potassium could have a much longer life than expected.
The study also poses a question on the notion that the big volume changes occurring during the electrochemical reaction are always a precursor to particle fracture, which primarily causes electrode failure eventually leading to battery degradation.
While research continues, the new findings could prove instrumental in helping scientists design battery systems based on sodium and potassium cores. As for the time being lithium batteries are high on demand for their higher energy density but speculations are that sodium and potassium batteries could be a thing of the future as they are abundant in supply and might serve as a cheaper alternative. This could be vital for large-scale energy storage such as backup power for homes or the energy grid of the future.