Scientists have discovered the source of a problem limiting the durability of sodium-ion batteries. Scientists provided manufacturers with new strategies for powering the 21st century. Sodium-ion batteries are a promising technology for electric vehicles. As they are made from abundant materials that are energy dense.
Also, they operate well in colder temperatures. Scientists have yet to perfect the chemistry. The lithium-ion batteries found in modern electronics can recharge thousands of times. But most variations of sodium-ion batteries can only cycle a small fraction of that.
The poor durability stems from a specific atomic reshuffling in the battery’s operation. It is the P2-O2 phase transition. Ions travel through the battery disorder crystal structures. They eventually break them. The phase transition has been of interest to scientists. The mechanisms behind it have been difficult to study.
Key aspects of that mechanism have been discovered by scientists. The study has been published in the journal Advanced Energy Materials.
Scientists found that sodium ions move through the battery. The misorientation of crystal layers inside individual particles increases before the layers. They align just prior to the P2-O2 phase transition.
Scientists observed the phenomenon after developing a new X-ray imaging technique. It allowed them to observe the behaviour of single particles within their battery sample, in real time and in mass scale.
The new findings led scientists to propose new design options for the type of sodium-ion battery they were using. They planned to investigate in future research projects. They said, one solution is to modify the battery chemistry to introduce a strategic disorder to the particles. It needs to happen just before the flawed transition phase.
Scientists said the new characterization technique can reveal complex phase behaviours in other nanoparticle systems. It can also be used in next-generation energy storage technologies.