The novel melted electrolyte can be coated onto the electrodes in lithium-ion batteries.
The novel melted electrolyte can be coated onto the electrodes in lithium-ion batteries.

A team of researchers from South Korea and the US has discovered a new way to produce all-solid-state lithium-ion batteries. Their method involves melting the solid electrolyte and then coating it onto the battery electrodes, and is detailed in a paper in Advanced Materials.

The organic liquid electrolyte used in existing lithium-ion batteries is highly flammable at high temperatures, hence the interest in solid-sate lithium batteries with solid electrolytes that are not flammable. Unfortunately, solid electrolytes do not transport lithium ions as effectively as liquid electrolytes and also do not interact as well with the electrodes, hampering the performance of solid-state lithium-ion batteries.

To solve these problems, the research team, led by Yoon Seok Jung at the Ulsan National Institute of Science and Technology (UNIST), has developed a way to coat a solid electrolyte onto the electrodes. This process involves dissolving the electrode material as a powder in the melted solid electrolyte and then vaporizing the solvent, which in this case is methanol. This converts the melted electrolyte into a form that can subsequently be coated onto the electrodes, where it cools to form a solid covering.

The research team also developed a novel solid electrolyte for this purpose. They did this by adding lithium iodide (LiI) to a compound comprising lithium, tin and sulfur (Li4SnS4), with the LiL helping to enhance the compound's ionic conductivity. Consequently, by combining two materials together, it became possible to produce a solid electrolyte with high ion conductivity and air stability.

"A newly developed solid electrolyte has the high ion conductivity and no toxicity problem," said Jung. "In addition, the prices of a raw material and methanol are comparatively low. With this technology, commercialization of solid lithium battery will be available sooner than we thought."

This story is adapted from material from UNIST, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.