A recent study by the Karlsruhe Institute of Technology (KIT) has shown that the formation of the solid electrolyte interphase, which is crucial for the functioning of lithium-ion batteries, occurs through the aggregation of solutions rather than directly at the electrode.

The findings offer insights into developing more efficient and long-lasting batteries in the future.

The researchers reached this conclusion through simulations, and the results of their study have been published in the Advanced Energy Materials journal.

These batteries, including liquid electrolyte batteries, function reliably on a solid electrolyte interphase (SEI) that forms when voltage is applied for the first time.

The passivation layer, also known as the solid electrolyte interphase (SEI), plays a crucial role in a lithium-ion battery’s electrochemical capacity and lifetime, as it is subjected to high stress during every charging cycle.

When the SEI is broken down, the electrolyte is further decomposed, resulting in reduced battery capacity, ultimately determining the battery’s lifetime.

Controlling the properties of a battery requires a thorough understanding of the SEI’s growth and composition. However, hitherto no approach has been able to decipher SEI’s complex growth processes at broad scales and dimensions.

It has remained a mystery how the particles in the electrolytes form a passivation layer up to 100 nanometers thick on the surface of the electrode, as the decomposition reaction is only possible within a few nanometers distance from the surface.

The new study from KIT has successfully characterized the formation of the solid electrolyte interphase (SEI) using a multi-scale approach, solving a major mystery regarding the functioning of liquid electrolyte batteries.

To understand the formation and properties of the passivation layer in liquid electrolyte batteries, KIT’s Institute of Nanotechnology conducted over 50,000 simulations with various reaction conditions.

The team discovered that the SEI follows a solution-mediated pathway, where SEI precursors formed directly at the surface join far away from the electrode surface via nucleation.

This process forms a porous layer that eventually covers the electrode surface.

Researchers can develop suitable electrolytes and additives to control SEI properties and optimize battery performance and lifespan by identifying key reaction parameters that determine SEI thickness.

Recently, researchers at the Shandong Academy of Medical Sciences, China, and Kyushu Institute of Technology, Japan, upcycled crab shells into porous, carbon-filled materials with various uses, including crab carbon, to create anode materials for sodium-ion batteries.

Earlier this month, researchers at South Korea’s Ulsan National Institute of Science and Technology developed a perovskite solar cell using alkylammonium chloride to control the formation of defects in the perovskite layer.