A new study has given hope to the trial-and-error theory of all-solid lithium batteries. Scientists from the National Institute for Materials Science have managed to visualize the nanoscale range in potential distribution in the composite cathode materials of solid state lithium ion batteries. This was accomplished both before and after charging the batteries. It’s hard to overstate the significance of these results regarding lithium ion batteries; it could pinpoint one of the most taxing problems in creating high power density batteries of this nature.
The problem, in short, is the high resistance of the electrode-electrolyte interfaces. The solid state lithium ion batteries have a significantly higher transfer resistance rate, compared to the current models that power our home devices. Increasing the power density is easier said than done; scientists have struggled to find a way to make these batteries more reliable and feasible in daily life.
Unfortunately, the batteries do not lend themselves to easy research. Electrical potential distribution — a vital component to understanding the solid state batteries — was difficult if not impossible without compromising the performance of the battery as a whole. The test results would be unreliable at best, useless at worst. This new nanoscale visualization may hold the key.
The research team managed this feat by cutting out samples from the sold state batteries. These samples were then treated and measured with a scanning probe microscope while under an inert gas (or in a vacuum). By doing this, the researchers were able to visualize the change in distribution as the battery charged and discharged. The batteries operated at normal capacity, allowing scientists to review them as if they were still whole while reviewing the electrical potential distribution. Testing showed that areas where lithium ion concentrations decreased were expanded in the solid electrolyte region.
This new method of visualization has not only given scientists a new understanding of solid state lithium ion batteries. It has managed to offer insight into the design and production of these power sources for mass production and usage.