TU Munich develops electrolyte for solid-state battery with high conductivity

Long range and short charging times – that is the dream of all electric car drivers. Solid-state batteries, also known as solid-state batteries, should make this possible. A team at the Technical University of Munich (TUM) has developed a new material that should make these batteries more powerful.

The team led by chemist Thomas Fässler has developed an electrolyte that conducts lithium ions faster than any previously known material. The material consists of lithium, antimony, and scandium. Until now, lithium-sulphur compounds have been used for solid electrolytes, to which five other elements are added for optimization.

The researchers have also modified the crystal lattice of the electrolyte: They have replaced three lithium atoms with one scandium atom, in each case – Scandium is a transition metal and belongs to the rare earth metals. This creates vacancies in the lattice that enable lithium ions to move more easily and quickly.

Significantly improved conductivity

This significantly improves the conductivity of the material. It conducts lithium ions over 30 percent faster than all previously known materials, the team writes in the journal Advanced Energy Materials. Because the conductivity is so much better than that of other materials, the team turned to colleagues from the Chair of Technical Electrochemistry to verify the result.

“Our combination consists of lithium antimony and can easily be transferred to lithium phosphorus,” said Jingwen Jiang, first author of the study. “We assume that our discovery may have significance beyond this example for increasing conductivity in other substances.”

According to Fässler, the result is an important step forward in basic research: “By incorporating small amounts of scandium, we have discovered a new principle that could prove to be groundbreaking for other element combinations.” As it conducts not only ions but also electrons, the material could also be integrated as an additive in electrodes.

However, he emphasized that many tests are still required before it can be used in battery cells. However, the team has already applied for a patent for the development.

Solid-state batteries not only have a significantly higher energy density, they can also be charged faster than a lithium-ion battery. In addition, they cannot catch fire and are therefore safer. However, they are currently still more expensive than conventional lithium-ion batteries.

(wpl)