This method allows the manufacture of more reliable and durable solid-electrolyte batteries – technology – hybrid and electric

researchers Indian Institute of Science (IISc) They discovered a major reason why solid-state lithium batteries fail. Taking advantage of this knowledge, they devised a method that allows them to develop a creation strategy Longer life, faster and more reliable charging from current. To reach these conclusions, the team studied the formation of dendrites in solid-state batteries, which are one of the most viable alternatives to replacing existing lithium batteries with liquid electrolytes.

The researchers found that the appearance of microscopic spaces on one of the poles of the device It is a major cause of the formation of dendrites, which are thin filaments that cross the barrier separating the cathode and anode. Can cause dendrites shorts Thus the entire battery malfunctions, which is why scientists have worked for years to get to the root of the problem.

Bifurcations in solid electrolyte batteries?

In batteries with a solid electrolyte, the medium through which the lithium ions travel from the electrode becomes a liquid, a solid, usually ceramic. In addition, the graphite that is commonly used in the anode is replaced to create its microstructure metallic lithium.

At higher temperatures, ceramic electrolytes tend to perform better than those based on other materials (which is particularly useful in the country in which the research was conducted). The lithium anode is also lighter and stores more charge than the graphite, which greatly reduces the cost of battery production.

However, as with wet electrolyte batteries, Solid state batteries also suffer from dendrite growth Under certain conditions, which can also cause a short circuit between the anode and cathode, explains Naga Phani Aetukuri, assistant professor in the Structural and Solid State Chemistry Unit (SSCU) at the Indian Institute of Science and project manager.

To investigate why this happens, PhD student Vikalp Raj of the Aetukuri team Artificially forming dendrites in the battery By repeatedly charging hundreds of cells, sculpting thin sections of the lithium-electrolyte interface, and examining them under a scanning electron microscope.

In this way, the team discovered that microscopic voids with currents at their edges about 10,000 times greater than average currents were forming at the lithium anode during discharge, causing the Stress the solid electrolyte and accelerate the growth of dendrites.

Solution: add metals to the electrolyte

As Aetukuri explained, “This means that our task now to make very good batteries is very simple: all we need to do is make sure that no voids form.”

However, he also acknowledges that this is easier said than done. The IISc team used their finding to develop a technique that they said could significantly delay the formation of these dendrites: Add a thin layer of metals to the surface of the electrolytealso. This solution also extends battery life and enables faster charging.

To solve the problem, the researchers placed an extremely thin layer of refractory metal between the lithium anode and the solid electrolyte as a shield to protect the solid electrolyte from stress and redistribute the current. A heat-resistant metal is a metal that is resistant to heat and corrosion.

To implement this part of the project, the Indian team collaborated with researchers from Carnegie Mellon University Perform the computational analysis. This study showed to the research team that the refractory metal layer effectively inhibited the growth of lithium microscopic voids.